body.training-page {
  text-align: left;
  --trainer-header: 3.5rem;
  --trainer-chrome: 7rem;
  --trainer-side-max: calc(100dvh - var(--trainer-header) - 18px);
}

html[data-theme="dark"] body.training-page {
  background:
    radial-gradient(ellipse 90% 42% at 50% -8%, color-mix(in srgb, var(--gold) 14%, transparent), transparent 58%),
    radial-gradient(ellipse 36% 28% at 100% 108%, color-mix(in srgb, var(--gold) 7%, transparent), transparent 55%),
    var(--bg);
}

html[data-theme="dark"] body.training-page #info-box,
html[data-theme="dark"] body.training-page #line-menu-container {
  position: relative;
  background: var(--bg-2);
  border: 1px solid color-mix(in srgb, var(--gold) 34%, transparent);
  box-shadow:
    inset 0 1px 0 color-mix(in srgb, var(--gold-bright) 16%, transparent),
    0 0 0 1px color-mix(in srgb, var(--gold) 8%, transparent),
    0 18px 44px rgba(0, 0, 0, 0.42);
}

html[data-theme="dark"] body.training-page #info-content {
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.045), color-mix(in srgb, var(--gold) 6%, transparent));
  border: 1px solid color-mix(in srgb, var(--gold) 22%, transparent);
  box-shadow: none;
}

html[data-theme="dark"] body.training-page #board {
  box-shadow:
    0 0 0 1px color-mix(in srgb, var(--gold) 24%, transparent),
    0 18px 48px rgba(0, 0, 0, 0.46);
}

html[data-theme="dark"] body.training-page .line-progress-wrap,
html[data-theme="dark"] body.training-page .practice-points-hud,
html[data-theme="dark"] body.training-page .line-status-panel,
html[data-theme="dark"] body.training-page .studio-section {
  border-color: color-mix(in srgb, var(--gold) 22%, transparent);
  background:
    linear-gradient(180deg, color-mix(in srgb, var(--gold) 8%, transparent), rgba(255, 255, 255, 0.03));
}

html[data-theme="dark"] body.training-page main.course-studio .line-menu-count {
  border-color: color-mix(in srgb, var(--gold) 38%, transparent);
  color: var(--gold-bright);
}

html[data-theme="dark"] body.training-page main.course-studio #studio-line-list li.active {
  background: linear-gradient(90deg, color-mix(in srgb, var(--gold) 20%, transparent), color-mix(in srgb, var(--gold) 4%, transparent));
}

html[data-theme="dark"] body.training-page #line-progress-fill {
  background: linear-gradient(90deg, var(--gold), var(--gold-bright));
  box-shadow: 0 0 10px color-mix(in srgb, var(--gold) 40%, transparent);
}

html[data-theme="dark"] body.training-page main.opening-view .trainer-session .trainer-mode.active,
html[data-theme="dark"] body.training-page main.opening-view .trainer-session .side-choice.active {
  background: color-mix(in srgb, var(--gold) 16%, transparent);
  color: #f5f3ff;
}

html[data-theme="dark"] body.training-page main.opening-view #line-menu-container .line-menu-count {
  border-color: color-mix(in srgb, var(--gold) 38%, transparent);
  color: var(--gold-bright);
}

html[data-theme="dark"] body.training-page main.opening-view #line-menu li.selected-line,
html[data-theme="dark"] body.training-page main.opening-view #line-menu li.active {
  background: color-mix(in srgb, var(--gold) 14%, transparent);
  border-color: color-mix(in srgb, var(--gold) 30%, transparent);
}

@media (min-width: 1181px) {
  body.training-page {
    height: 100dvh;
    overflow: hidden;
  }

  body.training-page .page-shell {
    flex: 1;
    min-height: 0;
    overflow: hidden;
  }

  body.training-page .page-shell:has(> .opening-view),
  body.training-page .page-shell:has(> .tree-view),
  body.training-page .page-shell:has(> .course-studio) {
    padding: 12px;
    container-type: inline-size;
  }

  main.opening-view,
  main.tree-view {
    flex: none;
    min-height: 0;
    padding: 0;
    --trainer-rail: 280px;
    --trainer-gap: 8px;
    --trainer-board: min(
      calc(100dvh - var(--trainer-header) - 24px),
      calc(100vw - 48px - (var(--trainer-rail) * 2) - (var(--trainer-gap) * 2))
    );
    display: grid;
    grid-template-columns: var(--trainer-rail) var(--trainer-board) var(--trainer-rail);
    grid-template-rows: auto;
    column-gap: var(--trainer-gap);
    row-gap: 0;
    align-items: start;
    justify-content: center;
    width: max-content;
    max-width: 100%;
    margin-inline: auto;
  }

  main.opening-view #board-container,
  main.tree-view #board-container {
    display: contents;
  }

  main.opening-view #info-box,
  main.tree-view #info-box {
    grid-column: 1;
    grid-row: 1;
    height: var(--trainer-board);
    max-height: var(--trainer-board);
    align-self: start;
  }

  main.opening-view #board-stage,
  main.tree-view #board-stage {
    grid-column: 2;
    grid-row: 1;
    width: 100%;
    max-width: none;
    justify-self: center;
    align-self: start;
  }

  main.opening-view #line-menu-container,
  main.tree-view #line-menu-container {
    grid-column: 3;
    grid-row: 1;
    height: var(--trainer-board);
    max-height: var(--trainer-board);
    align-self: start;
  }

  main.course-studio {
    --trainer-rail: 340px;
    --trainer-gap: 12px;
    --trainer-board: min(
      calc(100dvh - var(--trainer-header) - 32px),
      calc(100vw - 48px - (var(--trainer-rail) * 2) - (var(--trainer-gap) * 2))
    );
    flex: none;
    min-height: 0;
    max-height: calc(100dvh - var(--trainer-header) - 24px);
    padding: 0;
    display: grid;
    grid-template-columns: var(--trainer-rail) var(--trainer-board) var(--trainer-rail);
    grid-template-rows: auto;
    column-gap: var(--trainer-gap);
    row-gap: 0;
    align-items: stretch;
    justify-content: center;
    width: max-content;
    max-width: 100%;
    margin-inline: auto;
  }

  main.course-studio #info-box,
  main.course-studio #line-menu-container {
    height: var(--trainer-board);
    max-height: calc(100dvh - var(--trainer-header) - 24px);
    min-height: 0;
    align-self: stretch;
  }

  main.course-studio #board-container {
    justify-content: center;
    padding: 0;
    gap: 0;
    max-height: calc(100dvh - var(--trainer-header) - 24px);
  }

  main.course-studio #board-stage {
    width: var(--trainer-board);
    height: var(--trainer-board);
    max-width: 100%;
    max-height: var(--trainer-board);
  }

  main.course-studio #board {
    width: 100%;
    height: 100%;
    max-height: 100%;
  }
}

main.opening-view,
main.tree-view,
main.course-studio {
  display: grid;
  grid-template-columns: minmax(220px, 252px) minmax(0, 1fr) minmax(220px, 268px);
  align-items: stretch;
  gap: 10px;
  padding: 4px 0 8px;
  width: 100%;
  min-height: calc(100dvh - var(--trainer-header));
}

main.opening-view {
  --trainer-rail: 280px;
  --trainer-chrome: 8.5rem;
  --trainer-board: calc(100dvh - var(--trainer-chrome));
  grid-template-columns: var(--trainer-rail) minmax(0, 1fr) var(--trainer-rail);
  gap: 8px;
  padding: 8px 0 12px;
  min-height: 0;
  width: min(100%, calc(var(--trainer-rail) * 2 + var(--trainer-board) + 16px));
  margin-inline: auto;
}

@media (min-width: 1181px) {
  main.opening-view,
  main.tree-view {
    --trainer-gap: 8px;
    --trainer-board: min(
      calc(100dvh - var(--trainer-header) - 24px),
      calc(100vw - 48px - (var(--trainer-rail) * 2) - (var(--trainer-gap) * 2))
    );
    grid-template-columns: var(--trainer-rail) var(--trainer-board) var(--trainer-rail);
    grid-template-rows: auto;
    column-gap: var(--trainer-gap);
    row-gap: 0;
    align-items: start;
    padding: 0;
    width: max-content;
    max-width: 100%;
  }

  main.course-studio {
    --trainer-gap: 12px;
    --trainer-board: min(
      calc(100dvh - var(--trainer-header) - 32px),
      calc(100vw - 48px - (var(--trainer-rail) * 2) - (var(--trainer-gap) * 2))
    );
    grid-template-columns: var(--trainer-rail) var(--trainer-board) var(--trainer-rail);
    grid-template-rows: auto;
    column-gap: var(--trainer-gap);
    row-gap: 0;
    align-items: stretch;
    padding: 0;
    width: max-content;
    max-width: 100%;
    min-height: 0;
    max-height: calc(100dvh - var(--trainer-header) - 24px);
    margin-inline: auto;
  }

  main.course-studio #info-box,
  main.course-studio #line-menu-container {
    height: var(--trainer-board);
    max-height: calc(100dvh - var(--trainer-header) - 24px);
    min-height: 0;
    align-self: stretch;
  }

  main.course-studio #board-container {
    justify-content: center;
    padding: 0;
    gap: 0;
    max-height: calc(100dvh - var(--trainer-header) - 24px);
  }

  main.course-studio #board-stage {
    width: var(--trainer-board);
    height: var(--trainer-board);
    max-width: 100%;
    max-height: var(--trainer-board);
  }

  main.course-studio #board {
    width: 100%;
    height: 100%;
    max-height: 100%;
  }
}

main.course-studio {
  --trainer-chrome: 11rem;
  --trainer-rail: 340px;
  --trainer-gap: 12px;
}

main.tree-view {
  --trainer-rail: 280px;
  --trainer-chrome: 8.5rem;
}

main.tree-view #info-box {
  overflow: hidden;
  padding: 0;
}

main.tree-view .tree-side-scroll {
  flex: 1 1 auto;
  min-height: 0;
  overflow: auto;
  padding: 16px 14px 12px;
}

main.tree-view #board-controls {
  flex: 0 0 auto;
  justify-content: space-between;
  gap: 10px;
  width: 100%;
  padding: 10px 12px 12px;
  border-top: 1px solid var(--line);
  background: var(--paper);
}

main.tree-view #board-stage {
  position: relative;
}

main.tree-view .deviation-toast {
  position: absolute;
  z-index: 6;
  left: 8px;
  right: 8px;
  top: 8px;
  width: auto;
}

main.tree-view #info-content {
  min-height: 0;
}

main.tree-view #line-menu-container h2 {
  font-size: 1.45rem;
  margin-bottom: 10px;
}

main.tree-view #line-menu-container h2.tree-subhead {
  margin: 40px 0 14px;
  padding-top: 24px;
  font-size: 1.15rem;
}

#info-box,
#line-menu-container,
#board-container {
  display: flex;
  flex-direction: column;
  background: var(--panel);
  border: 1px solid var(--line-strong);
  border-radius: 14px;
  box-shadow: var(--panel-glow);
}

#info-box,
#line-menu-container {
  background: var(--paper);
  border: 1px solid var(--line);
  box-shadow: none;
}

#info-box,
#line-menu-container {
  width: auto;
  min-width: 0;
  min-height: 0;
  max-height: var(--trainer-side-max);
  overflow: auto;
  padding: 16px 14px;
}

#info-box h2,
#line-menu-container h2 {
  margin: 0 0 14px;
  font-family: var(--serif);
  font-size: clamp(1.6rem, 2vw, 2.05rem);
  font-weight: 600;
  line-height: 1.15;
  color: var(--cream);
}

#info-content {
  min-height: 7.5rem;
  overflow-y: auto;
  padding: 16px 16px 14px;
  font-size: 1.12rem;
  line-height: 1.7;
  color: var(--cream);
  background: var(--fill-subtle);
  border: 1px solid transparent;
  border-radius: 12px;
}

main.opening-view #info-content {
  flex: 0 1 auto;
  min-height: 0;
  padding: 12px 13px;
  font-size: 0.92rem;
  line-height: 1.55;
}

main.opening-view #info-box,
main.course-studio #info-box {
  overflow: hidden;
  padding: 14px 14px 12px;
}

main.opening-view #info-box {
  padding: 0;
}

main.opening-view #info-box h2,
main.course-studio #info-box h2 {
  margin: 0 0 12px;
  padding: 0 2px 10px;
  border-bottom: 1px solid color-mix(in srgb, var(--gold) 20%, var(--line));
  font-family: var(--font);
  font-size: 0.98rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.3;
}

main.opening-view #info-box h2 {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex: 0 0 auto;
  margin: 0;
  padding: 14px 16px 13px;
  border-bottom: 1px solid var(--line);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  line-height: 1.2;
}

main.opening-view .trainer-side-scroll {
  flex: 1 1 auto;
  min-height: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 12px;
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: rgba(161, 161, 170, 0.45) transparent;
}

main.opening-view .trainer-side-scroll .line-progress-wrap,
main.opening-view .trainer-side-scroll .practice-points-hud,
main.opening-view .trainer-side-scroll .line-status-panel {
  margin-top: 0;
  padding: 11px 12px;
  border-radius: 10px;
}

main.opening-view .trainer-session {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding-bottom: 2px;
}

main.opening-view .trainer-session-block {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

main.opening-view .trainer-session-label {
  margin: 0;
  font-size: 0.58rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

main.opening-view .trainer-session .trainer-mode-row,
main.opening-view .trainer-session .trainer-side-row {
  display: grid;
  width: 100%;
  gap: 2px;
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--fill-subtle);
}

main.opening-view .trainer-session .trainer-mode-row {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

main.opening-view .trainer-session .trainer-side-row {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

main.opening-view .trainer-session .trainer-mode,
main.opening-view .trainer-session .side-choice,
main.opening-view .trainer-session-actions button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  width: 100%;
  min-height: 30px;
  padding: 5px 4px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--cream-dim);
  font-family: var(--font);
  font-size: 0.62rem;
  font-weight: 650;
  letter-spacing: 0;
  line-height: 1.2;
  text-align: left;
  white-space: nowrap;
  cursor: pointer;
}

main.opening-view .trainer-session .trainer-mode {
  justify-content: flex-start;
  padding-inline: 6px;
}

main.opening-view .trainer-session .trainer-mode .trainer-mode-emoji {
  flex: 0 0 auto;
  width: 1.1em;
  text-align: center;
  line-height: 1;
}

main.opening-view .trainer-session .trainer-mode .trainer-mode-label {
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
}

main.opening-view .trainer-session .trainer-mode.is-locked {
  opacity: 0.55;
  cursor: pointer;
}

main.opening-view .trainer-session .trainer-mode.is-locked:hover,
main.opening-view .trainer-session .trainer-mode.is-locked:focus-visible {
  opacity: 0.8;
  color: var(--cream);
  background: var(--hover-fill);
}

main.opening-view .trainer-session .trainer-mode:hover,
main.opening-view .trainer-session .side-choice:hover,
main.opening-view .trainer-session-actions button:hover {
  color: var(--cream);
  background: var(--hover-fill);
}

main.opening-view .trainer-session .trainer-mode.active,
main.opening-view .trainer-session .side-choice.active {
  background: var(--paper);
  color: var(--cream);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.22);
}

main.opening-view .trainer-session-actions {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
}

main.opening-view .trainer-session-actions button {
  border: 1px solid var(--line);
  background: transparent;
  color: var(--muted);
}

main.opening-view .trainer-session-actions button:hover {
  border-color: var(--line-strong);
  color: var(--cream);
}

main.opening-view .trainer-settings {
  margin-top: 2px;
  padding: 2px 0 4px;
  border-top: 0;
}

main.opening-view #progress-panel h3 {
  margin: 0 0 8px;
  font-family: var(--font);
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

main.opening-view .line-status-name {
  font-size: 0.92rem;
}

main.opening-view .line-status-note {
  font-size: 0.8rem;
  line-height: 1.45;
}

#info-box.celebration {
  outline: 2px solid var(--gold);
}

#line-menu,
#tree-move-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

#line-menu li,
#tree-move-list li {
  padding: 14px 14px;
  cursor: pointer;
  border: 1px solid var(--line);
  background: var(--bg-3);
  color: var(--cream);
  font-size: 1.02rem;
  font-weight: 600;
}

#line-menu li:hover,
#line-menu li.active,
#line-menu li.selected-line,
#tree-move-list li.selected-line {
  border-color: var(--gold);
  background: rgba(127, 127, 127, 0.12);
  color: var(--gold-bright);
}

#line-menu li.mastered-line {
  border-color: var(--gold);
}

#line-menu li.mastered-line::after {
  content: "Mastered";
  display: block;
  margin-top: 4px;
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gold-bright);
  font-weight: 700;
}

main.opening-view .trainer-side-panel,
main.opening-view #info-box,
main.opening-view #line-menu-container,
main.tree-view #info-box,
main.tree-view #line-menu-container {
  align-self: stretch;
  height: 100%;
  max-height: none;
  overflow: hidden;
  padding: 0;
  background: var(--paper);
  border: 1px solid var(--line-strong);
  border-radius: 12px;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.04),
    0 10px 24px rgba(0, 0, 0, 0.22);
}

/* Remove the "gray outer shell" from opening and endgame training pages:
   the container's panel glow and the board's 12px border. The review page
   already removed its board border; these follow the same pattern. */
main.opening-view #board-container,
main.tree-view #board-container {
  box-shadow: none;
  background: transparent;
}
main.opening-view #board,
main.tree-view #board {
  border: none;
}

main.opening-view #board-container {
  justify-content: flex-start;
  padding: 0;
  gap: 4px;
}

@media (min-width: 1181px) {
  main.opening-view #board-container,
  main.tree-view #board-container {
    display: contents;
  }

  main.opening-view #info-box,
  main.opening-view #line-menu-container,
  main.tree-view #info-box,
  main.tree-view #line-menu-container {
    height: var(--trainer-board);
    max-height: var(--trainer-board);
    align-self: start;
  }

  main.opening-view #board-stage,
  main.tree-view #board-stage {
    width: 100%;
    max-width: none;
  }
}

main.opening-view #line-menu-container:has(.trainer-course-switch.is-open) {
  overflow: visible;
  z-index: 3;
}

main.opening-view .trainer-course-switch {
  position: relative;
  flex: 0 0 auto;
  z-index: 2;
  margin: 0;
  padding: 10px 10px 0;
}

main.opening-view .trainer-course-switch[hidden] {
  display: none;
}

main.opening-view .trainer-course-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  width: 100%;
  min-height: 0;
  padding: 4px 6px 8px;
  border: 0;
  border-bottom: 1px solid var(--line);
  border-radius: 0;
  background: transparent;
  box-shadow: none;
  color: var(--cream);
  font-family: var(--font);
  text-align: left;
  cursor: pointer;
}

main.opening-view .trainer-course-switch.is-open .trainer-course-toggle,
main.opening-view .trainer-course-toggle:hover,
main.opening-view .trainer-course-toggle:focus-visible {
  border-color: var(--line);
  background: transparent;
  box-shadow: none;
  outline: none;
}

main.opening-view .trainer-course-name {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 0.92rem;
  font-weight: 650;
  letter-spacing: -0.01em;
  line-height: 1.25;
  color: var(--cream);
}

main.opening-view .trainer-course-chevron {
  flex: 0 0 auto;
  width: 12px;
  height: 12px;
  color: var(--muted);
  transition: transform 0.16s ease;
}

main.opening-view .trainer-course-switch.is-open .trainer-course-chevron {
  transform: rotate(180deg);
}

main.opening-view .trainer-course-menu {
  position: absolute;
  top: calc(100% - 1px);
  left: 8px;
  right: 8px;
  z-index: 6;
  display: flex;
  flex-direction: column;
  gap: 1px;
  padding: 6px;
  border: 1px solid var(--line-strong);
  border-radius: 10px;
  background: var(--paper);
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.03) inset,
    0 16px 40px rgba(0, 0, 0, 0.38);
}

main.opening-view .trainer-course-menu[hidden] {
  display: none;
}

main.opening-view .trainer-course-option {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  width: 100%;
  padding: 7px 8px;
  border: 0;
  border-radius: 7px;
  background: transparent;
  color: var(--cream-dim);
  font-family: var(--font);
  text-align: left;
  cursor: pointer;
}

main.opening-view .trainer-course-option:hover,
main.opening-view .trainer-course-option:focus-visible {
  background: var(--hover-fill);
  color: var(--cream);
  outline: none;
}

main.opening-view .trainer-course-option.is-active {
  background: color-mix(in srgb, var(--gold) 10%, transparent);
  color: var(--cream);
  box-shadow: none;
}

main.opening-view .trainer-course-option-title {
  overflow: hidden;
  min-width: 0;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 0.8rem;
  font-weight: 500;
}

main.opening-view .trainer-course-option-check {
  flex: 0 0 auto;
  width: 8px;
  height: 8px;
  border-radius: 99px;
  background: transparent;
}

main.opening-view .trainer-course-option.is-active .trainer-course-option-check {
  background: var(--gold);
}

main.opening-view .line-menu-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex: 0 0 auto;
  padding: 8px 10px 8px 14px;
}

main.opening-view #line-menu-container .line-menu-head > h2 {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: 12px;
  flex: 1 1 auto;
  min-width: 0;
  margin: 0;
  padding: 0;
  border-bottom: 0;
  font-family: var(--font);
  font-size: 0.62rem;
  font-weight: 400;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

main.opening-view .line-menu-head .nav-arrow-group {
  flex: 0 0 auto;
  padding: 2px;
}

main.opening-view .line-menu-head .nav-arrow {
  width: 34px;
  min-width: 34px;
  height: 34px;
  min-height: 34px;
  padding: 0;
  display: grid;
  place-items: center;
  border: 0;
  border-radius: 999px;
  color: var(--cream);
  background: transparent;
  box-shadow: none;
  cursor: pointer;
}

main.opening-view .line-menu-head .nav-arrow svg {
  display: block;
  width: 16px;
  height: 18px;
  fill: currentColor;
}

main.opening-view .line-menu-head .nav-arrow:hover:not(:disabled),
main.opening-view .line-menu-head .nav-arrow:focus-visible {
  background: transparent;
  box-shadow: none;
  color: var(--gold-bright);
}

main.opening-view .line-menu-head .nav-arrow:disabled {
  opacity: 0.35;
}

main.opening-view #line-menu-container .line-menu-count {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.5rem;
  padding: 2px 7px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--fill-subtle);
  font-size: 0.66rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-transform: none;
  color: var(--cream-dim);
  font-variant-numeric: tabular-nums;
}

main.opening-view .trainer-line-scroll {
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  padding: 0 8px 10px;
  scrollbar-width: thin;
  scrollbar-color: rgba(161, 161, 170, 0.45) transparent;
}

main.opening-view .trainer-line-scroll::-webkit-scrollbar {
  width: 8px;
}

main.opening-view .trainer-line-scroll::-webkit-scrollbar-thumb {
  background: rgba(161, 161, 170, 0.4);
  border-radius: 99px;
}

main.opening-view #line-menu {
  flex: 0 0 auto;
  min-height: 0;
  overflow: visible;
  gap: 4px;
  padding: 0;
  border: none;
  border-radius: 0;
  background: transparent;
  counter-reset: line-n;
}

main.opening-view #line-menu li {
  display: grid;
  grid-template-columns: 1.7rem minmax(0, 1fr) auto;
  align-items: center;
  column-gap: 8px;
  margin: 0;
  padding: 9px 10px;
  border: 1px solid transparent;
  border-bottom: 1px solid transparent;
  border-radius: 8px;
  background: transparent;
  box-shadow: none;
  font-size: 0.86rem;
  font-weight: 500;
  line-height: 1.35;
  color: var(--cream-dim);
}

main.opening-view #line-menu li::before {
  counter-increment: line-n;
  content: counter(line-n, decimal-leading-zero);
  font-size: 0.64rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

main.opening-view #line-menu .line-menu-name {
  min-width: 0;
}

main.opening-view #line-menu li:hover {
  border-color: var(--line);
  background: var(--hover-fill);
  color: var(--cream);
}

main.opening-view #line-menu li.selected-line,
main.opening-view #line-menu li.active {
  border-color: color-mix(in srgb, var(--gold) 28%, transparent);
  background: color-mix(in srgb, var(--gold) 12%, transparent);
  color: var(--cream);
  box-shadow: none;
}

main.opening-view #line-menu li.selected-line::before,
main.opening-view #line-menu li.active::before {
  color: var(--gold-bright);
}

main.opening-view #line-menu li.mastered-line {
  border-color: transparent;
}

main.opening-view #line-menu li.mastered-line.selected-line {
  border-color: color-mix(in srgb, var(--gold) 28%, transparent);
}

main.opening-view #line-menu li.mastered-line::after {
  display: inline-flex;
  align-items: center;
  margin: 0;
  padding: 2px 6px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: transparent;
  font-size: 0.55rem;
  letter-spacing: 0.08em;
  color: var(--muted);
  white-space: nowrap;
}

main.tree-view #line-menu-container {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  padding: 16px 12px 12px;
}

main.tree-view #line-menu-container > h2 {
  flex: 0 0 auto;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin: 0 2px 8px;
  padding: 0 4px 10px;
  border-bottom: 1px solid var(--line);
  font-size: 1.15rem;
  font-weight: 600;
}

main.tree-view #line-menu-container h2.tree-subhead {
  margin: 16px 2px 8px;
  padding: 12px 4px 10px;
  font-size: 1.15rem;
}

main.tree-view #line-menu-container .line-menu-count {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

main.tree-view #book-status,
main.tree-view #deviation-status {
  flex: 0 0 auto;
  margin: 0 4px 10px;
  font-size: 0.82rem;
  line-height: 1.5;
}

main.tree-view #book-moves-list,
main.tree-view #book-deviation-list {
  flex: 1 1 0;
  min-height: 7rem;
  max-height: none;
  overflow-y: auto;
  gap: 6px;
  padding: 2px 2px 4px;
  scrollbar-width: thin;
  scrollbar-color: rgba(161, 161, 170, 0.45) transparent;
}

main.tree-view #book-moves-list::-webkit-scrollbar,
main.tree-view #book-deviation-list::-webkit-scrollbar {
  width: 8px;
}

main.tree-view #book-moves-list::-webkit-scrollbar-thumb,
main.tree-view #book-deviation-list::-webkit-scrollbar-thumb {
  background: rgba(161, 161, 170, 0.4);
  border-radius: 99px;
}

main.tree-view #book-moves-list li,
main.tree-view #book-deviation-list li {
  column-gap: 8px;
  min-height: 2.75rem;
  flex-shrink: 0;
  padding: 10px 10px 10px 8px;
  border-radius: 10px;
  background: var(--fill-subtle);
  font-size: 0.92rem;
  overflow: hidden;
}

main.tree-view #book-moves-list li .book-meta,
main.tree-view #book-deviation-list li .book-meta {
  flex-direction: row;
  align-items: baseline;
  gap: 6px;
  min-width: 0;
}

main.tree-view #book-moves-list li .book-san,
main.tree-view #book-deviation-list li .book-san {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

main.tree-view #book-moves-list li:hover {
  border-color: var(--line-strong);
  background: var(--hover-fill);
}

main.tree-view #book-moves-list li.book-played {
  border-color: var(--glow-line);
  background: color-mix(in srgb, var(--gold) 10%, transparent);
  box-shadow: inset 3px 0 0 var(--gold);
}

main.tree-view #book-moves-list li .book-rank,
main.tree-view #book-deviation-list li .dev-mark {
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  font-variant-numeric: tabular-nums;
}

main.tree-view #player-moves-list {
  gap: 6px;
}

main.tree-view #player-moves-list li {
  padding: 11px 12px;
  border-radius: 10px;
  background: var(--fill-subtle);
  font-size: 0.92rem;
}

main.tree-view #player-moves-list li:hover {
  border-color: var(--line-strong);
  background: var(--hover-fill);
  color: var(--cream);
}

#line-menu-container h2.tree-subhead {
  margin: 36px 0 10px;
  padding-top: 28px;
  border-top: 1px solid var(--line);
  font-size: 1.25rem;
  line-height: 1.35;
}

#book-status,
#deviation-status {
  margin: 0 0 16px;
  font-size: 0.9rem;
  line-height: 1.7;
  color: var(--cream-dim);
}

#deviation-status {
  margin-top: 4px;
}

#book-moves-list,
#book-deviation-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-height: 22rem;
  overflow-y: auto;
}

#book-moves-list.is-loading {
  pointer-events: none;
  opacity: 0.55;
}

main.tree-view #book-moves-list.is-loading {
  opacity: 0.5;
}

#book-moves-list li,
#book-deviation-list li {
  display: grid;
  grid-template-columns: 1.75rem minmax(0, 1fr) auto;
  column-gap: 16px;
  align-items: center;
  min-height: 3.2rem;
  padding: 12px 14px;
  border: 1px solid var(--line);
  background: var(--bg-3);
  color: var(--cream);
  font-size: 1rem;
  line-height: 1.4;
  cursor: pointer;
}

#book-moves-list li .book-rank,
#book-deviation-list li .dev-mark {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 700;
}

#book-moves-list li .book-san,
#book-deviation-list li .book-san {
  min-width: 0;
  font-weight: 650;
  letter-spacing: 0.02em;
}

#book-moves-list li .book-meta,
#book-deviation-list li .book-meta {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 6px;
  min-width: 3.4rem;
}

#book-moves-list li .book-pct,
#book-deviation-list li .book-count {
  color: var(--gold-bright);
  font-weight: 700;
  font-size: 0.88rem;
  line-height: 1.2;
}

#book-moves-list li .book-games,
#book-deviation-list li .book-games {
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  line-height: 1.2;
}

#book-moves-list li.book-played {
  border-color: var(--gold);
  background: rgba(127, 127, 127, 0.12);
}

#book-deviation-list li,
#tree-move-list li.ply-deviation {
  border-color: var(--danger-border);
  background: var(--danger-bg);
  color: var(--danger-text);
}

#tree-move-list li.ply-book {
  border-color: var(--gold);
}

#tree-move-list li .ply-tag {
  display: block;
  margin-top: 8px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  line-height: 1.45;
  text-transform: uppercase;
  color: var(--cream-dim);
}

#player-moves-list li.player-deviation {
  border-color: var(--danger-border);
  background: var(--danger-bg);
}

#board-container {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  justify-content: flex-start;
  gap: 8px;
  padding: 8px 12px 10px;
  min-width: 0;
  min-height: 0;
  background: transparent;
  border: none;
  box-shadow: none;
}

#board-stage {
  position: relative;
  width: min(100%, calc(100dvh - var(--trainer-chrome)));
}

#board {
  position: relative;
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  grid-template-rows: repeat(8, 1fr);
  width: 100%;
  aspect-ratio: 1;
  border: 12px solid var(--line-strong);
  /* Square-edged, like every other board on the site.

     A 24px radius on a 12px frame read as a rounded picture frame around the
     grid: the corners cut into the playing surface, the a-file and the 1st rank
     lost their corner squares to the curve, and the squares underneath kept
     going square while the frame clipped them. A chessboard is a grid, and the
     frame should not imply a different shape for what it contains.

     The border width is untouched — it is the frame the board-size parity tests
     measure by. */
  border-radius: 0;
  overflow: hidden;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.22);
}

#board-arrows {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 4;
  overflow: visible;
}

#board-arrows.player-book-arrows {
  z-index: 3;
}

#board-arrows .player-arrow {
  fill: var(--gold);
  stroke: rgba(250, 250, 250, 0.22);
  stroke-width: 0.012;
  stroke-linejoin: round;
}

#board-arrows .player-arrow.is-main {
  fill: var(--gold-bright);
  stroke: rgba(255, 251, 235, 0.35);
  stroke-width: 0.014;
}

#board-arrows .arrow-threat {
  fill: #e11d48;
  stroke: rgba(255, 241, 242, 0.35);
  stroke-width: 0.02;
  opacity: 0.92;
}

#board-arrows .arrow-plan {
  fill: var(--gold);
  stroke: rgba(255, 251, 235, 0.32);
  stroke-width: 0.018;
  opacity: 0.88;
}

#board-arrows .arrow-theory {
  stroke: var(--arrow-stroke, rgba(237, 233, 254, 0.35));
  stroke-width: 0.016;
}

html[data-theme="light"] #board-arrows .arrow-threat {
  fill: #be123c;
  stroke: rgba(24, 24, 27, 0.2);
}

html[data-theme="light"] #board-arrows .arrow-plan {
  fill: #a16207;
}

html[data-theme="light"] #board-arrows .player-arrow {
  fill: #a16207;
  stroke: rgba(24, 24, 27, 0.18);
}

html[data-theme="light"] #board-arrows .player-arrow.is-main {
  fill: var(--gold);
}

.square.theory-origin {
  position: relative;
  box-shadow: inset 0 0 0 3px var(--hl-origin, rgba(57, 255, 20, 0.85));
}

.square.theory-target {
  position: relative;
  box-shadow: inset 0 0 0 3px var(--hl-target, rgba(214, 255, 184, 0.95));
}

main.course-studio #board-arrows .arrow-theory {
  stroke: var(--arrow-stroke, rgba(255, 251, 235, 0.55));
  stroke-width: 0.02;
}

#line-complete-overlay {
  position: absolute;
  inset: 14px;
  z-index: 8;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  background: var(--overlay-bg);
  border: 2px solid var(--gold-bright);
  box-shadow: 0 0 48px rgba(127, 127, 127, 0.35);
  animation: line-complete-in 0.35s ease;
}

#line-complete-overlay[hidden] {
  display: none;
}

.timed-fail-overlay {
  position: absolute;
  inset: 14px;
  z-index: 9;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 18px;
  background: var(--overlay-bg);
  border: 2px solid color-mix(in srgb, #fb923c 70%, var(--gold-bright));
  box-shadow: 0 0 48px rgba(251, 146, 60, 0.22);
  animation: line-complete-in 0.35s ease;
  text-align: center;
}

.timed-fail-overlay[hidden] {
  display: none;
}

.timed-fail-restart {
  margin-top: 10px;
  min-height: 42px;
  padding: 0 18px;
}

.timed-setup-prompt[hidden] {
  display: none !important;
}

.timed-setup-prompt {
  position: absolute;
  inset: 0;
  z-index: 40;
  display: grid;
  place-items: center;
  padding: 18px;
}

.timed-setup-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(8, 9, 12, 0.55);
}

.timed-setup-card {
  position: relative;
  width: min(340px, 100%);
  padding: 22px 20px 18px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--cream);
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.35);
  text-align: center;
}

.timed-setup-close {
  position: absolute;
  top: 8px;
  right: 10px;
  border: 0;
  background: transparent;
  color: var(--muted);
  font-size: 1.4rem;
  line-height: 1;
  cursor: pointer;
}

.timed-setup-kicker {
  margin: 0;
  color: var(--gold);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.timed-setup-card h2 {
  margin: 8px 0 6px;
  font-size: 1.25rem;
}

.timed-setup-copy {
  margin: 0 0 14px;
  color: var(--muted);
  font-size: 0.88rem;
}

.timed-setup-options {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 8px;
  margin-bottom: 14px;
}

.timed-setup-btn {
  min-height: 40px;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper) 88%, #000);
  color: var(--cream);
  font-weight: 600;
  cursor: pointer;
}

.timed-setup-btn.is-on {
  border-color: var(--gold);
  color: var(--gold-bright);
  box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--gold) 35%, transparent);
}

.timed-setup-start {
  width: 100%;
}

html[data-theme="light"] .timed-setup-backdrop {
  background: rgba(20, 18, 14, 0.28);
}

html[data-theme="light"] .timed-setup-card {
  background: #fff;
  color: #1c1915;
}

.line-complete-kicker {
  margin: 0;
  font-size: 0.78rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gold-bright);
}

.line-complete-title {
  margin: 0;
  font-family: var(--font);
  font-size: clamp(2rem, 5vw, 3.4rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--cream);
  text-align: center;
  text-shadow: 0 0 28px rgba(127, 127, 127, 0.55);
}

.line-complete-sub {
  margin: 8px 0 0;
  color: var(--cream-dim);
  font-size: 1rem;
  text-align: center;
  max-width: 18rem;
}

@keyframes line-complete-in {
  from {
    opacity: 0;
    transform: scale(0.94);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.save-progress-prompt[hidden] {
  display: none !important;
}

.save-progress-prompt {
  position: fixed;
  inset: 0;
  z-index: 250;
  display: grid;
  place-items: center;
  padding: 24px;
}

.save-progress-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(9, 9, 11, 0.62);
}

.save-progress-card {
  position: relative;
  width: min(400px, 100%);
  padding: 26px 26px 22px;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--cream);
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.04) inset,
    0 24px 80px rgba(0, 0, 0, 0.42);
}

#save-progress-prompt .save-progress-card,
#learn-trial-prompt .save-progress-card {
  width: min(420px, 100%);
  padding: 32px 28px 26px;
  border-radius: 20px;
  text-align: center;
  border: 1px solid color-mix(in srgb, var(--gold) 38%, var(--line));
  background:
    radial-gradient(ellipse 90% 60% at 50% -10%, color-mix(in srgb, var(--gold) 16%, transparent), transparent 55%),
    linear-gradient(180deg, color-mix(in srgb, var(--paper) 92%, #fff 8%), var(--paper-2));
  overflow: hidden;
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.06) inset,
    0 1px 0 color-mix(in srgb, var(--gold) 18%, transparent) inset,
    0 28px 90px rgba(0, 0, 0, 0.55),
    0 0 60px color-mix(in srgb, var(--gold) 8%, transparent);
  animation: save-progress-rise 0.45s cubic-bezier(0.22, 1, 0.36, 1);
}

#save-progress-prompt .save-progress-backdrop,
#learn-trial-prompt .save-progress-backdrop {
  background:
    radial-gradient(ellipse 70% 50% at 50% 40%, color-mix(in srgb, var(--gold) 12%, transparent), transparent 70%),
    rgba(5, 5, 6, 0.72);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  animation: save-progress-fade 0.35s ease;
}

.save-progress-kicker {
  margin: 0 0 8px;
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

#save-progress-prompt .save-progress-kicker,
#learn-trial-prompt .save-progress-kicker {
  margin: 0 0 10px;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--gold);
}

.save-progress-card h2 {
  margin: 0 0 10px;
  font-family: var(--font);
  font-size: 1.28rem;
  font-weight: 650;
  letter-spacing: -0.03em;
  line-height: 1.25;
  color: var(--cream);
}

#save-progress-prompt .save-progress-card h2,
#learn-trial-prompt .save-progress-card h2 {
  margin: 0 0 12px;
  font-family: var(--serif);
  font-size: clamp(1.45rem, 3.6vw, 1.75rem);
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.2;
}

.save-progress-card p#save-progress-copy,
.save-progress-card p#learn-trial-copy {
  margin: 0 auto;
  max-width: 34ch;
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--muted);
}

.save-progress-close {
  position: absolute;
  top: 12px;
  right: 14px;
  width: 32px;
  height: 32px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--muted);
  font-size: 1.35rem;
  line-height: 1;
  cursor: pointer;
}

.save-progress-close:hover,
.save-progress-close:focus-visible {
  color: var(--cream);
  background: var(--fill-subtle);
}

.save-progress-seal {
  display: grid;
  place-items: center;
  width: 56px;
  height: 56px;
  margin: 0 auto 16px;
  color: var(--gold-bright);
  animation: save-progress-seal 0.7s cubic-bezier(0.22, 1, 0.36, 1) 0.08s both;
}

.save-progress-seal svg {
  width: 100%;
  height: 100%;
  filter: drop-shadow(0 0 18px color-mix(in srgb, var(--gold) 35%, transparent));
}

.save-progress-perks {
  list-style: none;
  margin: 22px 0 0;
  padding: 16px 16px 14px;
  display: flex;
  flex-direction: column;
  gap: 11px;
  text-align: left;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: color-mix(in srgb, var(--fill-subtle) 80%, transparent);
}

.save-progress-perks li {
  display: grid;
  grid-template-columns: 1rem 1fr;
  gap: 10px;
  align-items: start;
  font-size: 0.875rem;
  line-height: 1.45;
  color: var(--cream);
}

.save-progress-perks li span {
  color: var(--gold);
  font-size: 0.65rem;
  line-height: 1.7;
}

.save-progress-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 22px;
}

#save-progress-prompt .save-progress-actions,
#learn-trial-prompt .save-progress-actions {
  margin-top: 24px;
}

.save-progress-actions .btn {
  width: 100%;
  justify-content: center;
}

#save-progress-prompt .save-progress-actions .btn,
#learn-trial-prompt .save-progress-actions .btn {
  min-height: 46px;
  font-weight: 700;
  letter-spacing: 0.01em;
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.28);
}

.save-progress-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 36px;
  color: var(--cream-dim);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 600;
}

.save-progress-secondary:hover,
.save-progress-secondary:focus-visible {
  color: var(--gold-bright);
}

.save-progress-dismiss {
  border: 0;
  background: transparent;
  color: var(--muted);
  font-family: var(--font);
  font-size: 0.8125rem;
  font-weight: 600;
  cursor: pointer;
  padding: 6px 0 2px;
}

.save-progress-dismiss:hover,
.save-progress-dismiss:focus-visible {
  color: var(--cream);
}

@keyframes save-progress-fade {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes save-progress-rise {
  from {
    opacity: 0;
    transform: translateY(14px) scale(0.97);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes save-progress-seal {
  from {
    opacity: 0;
    transform: scale(0.72);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.learn-trial-card {
  width: min(420px, 100%);
}

.learn-trial-close {
  position: absolute;
  top: 12px;
  right: 14px;
  width: 32px;
  height: 32px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--muted);
  font-size: 1.35rem;
  line-height: 1;
  cursor: pointer;
}

.learn-trial-close:hover,
.learn-trial-close:focus-visible {
  color: var(--cream);
  background: var(--fill-subtle);
}

.learn-trial-perks {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.learn-trial-perks li {
  display: grid;
  grid-template-columns: 1.25rem 1fr;
  gap: 10px;
  align-items: start;
  font-size: 0.9rem;
  line-height: 1.45;
  color: var(--cream);
}

.learn-trial-perks li span {
  color: var(--gold);
  font-weight: 700;
}

.learn-trial-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  color: var(--cream);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 600;
}

.learn-trial-secondary:hover {
  color: var(--gold-bright);
}

.learn-trial-status {
  margin: 14px 0 0;
  font-size: 0.84rem;
  line-height: 1.45;
  color: var(--muted);
  text-align: center;
}

html[data-theme="light"] .save-progress-backdrop {
  background: rgba(24, 24, 27, 0.38);
}

html[data-theme="light"] .save-progress-card {
  box-shadow:
    0 0 0 1px rgba(24, 24, 27, 0.04) inset,
    0 24px 64px rgba(24, 24, 27, 0.16);
}

html[data-theme="light"] #save-progress-prompt .save-progress-backdrop,
html[data-theme="light"] #learn-trial-prompt .save-progress-backdrop {
  background:
    radial-gradient(ellipse 70% 50% at 50% 40%, color-mix(in srgb, var(--gold) 10%, transparent), transparent 70%),
    rgba(15, 23, 42, 0.42);
}

html[data-theme="light"] #save-progress-prompt .save-progress-card,
html[data-theme="light"] #learn-trial-prompt .save-progress-card {
  border-color: color-mix(in srgb, var(--gold) 42%, var(--line));
  background:
    radial-gradient(ellipse 90% 60% at 50% -10%, color-mix(in srgb, var(--gold) 12%, transparent), transparent 55%),
    linear-gradient(180deg, #fff, var(--paper-2));
  box-shadow:
    0 0 0 1px rgba(15, 23, 42, 0.04) inset,
    0 28px 72px rgba(15, 23, 42, 0.18),
    0 0 40px color-mix(in srgb, var(--gold) 6%, transparent);
}

html[data-theme="light"] #save-progress-prompt .save-progress-seal,
html[data-theme="light"] #learn-trial-prompt .save-progress-seal {
  color: var(--gold);
}

html[data-theme="light"] #save-progress-prompt .save-progress-perks,
html[data-theme="light"] #learn-trial-prompt .save-progress-perks {
  background: rgba(24, 24, 27, 0.03);
}

.square {
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  position: relative;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}

.square img {
  width: 92%;
  height: 92%;
  object-fit: contain;
  filter: drop-shadow(0 2px 3px rgba(0, 0, 0, 0.35));
  -webkit-user-drag: none;
  user-select: none;
  touch-action: none;
  pointer-events: auto;
}

.square img.is-lifted {
  opacity: 0.22;
}

.piece-ghost {
  position: fixed;
  left: 0;
  top: 0;
  margin: 0;
  padding: 0;
  border: 0;
  pointer-events: none;
  z-index: 400;
  filter: drop-shadow(0 10px 18px rgba(0, 0, 0, 0.45));
  will-change: transform;
}

#board.is-dragging,
#board.is-dragging .square {
  cursor: grabbing;
}

.white { background: var(--board-light); }
.black { background: var(--board-dark); }

.board-coord {
  position: absolute;
  z-index: 2;
  pointer-events: none;
  user-select: none;
  font-size: clamp(0.55rem, 1.2vw, 0.72rem);
  font-weight: 700;
  line-height: 1;
}

.board-coord-rank {
  top: 3px;
  left: 4px;
}

.board-coord-file {
  right: 4px;
  bottom: 3px;
}

.square.white .board-coord { color: var(--board-dark); }
.square.black .board-coord { color: var(--board-light); }

.square.highlight::after,
.square.last-move::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 1;
}

.square.highlight::after {
  background: var(--hl-select, rgba(124, 255, 74, 0.52));
}

.square.last-move-from::after {
  background: var(--hl-from, rgba(57, 255, 20, 0.48));
  animation: last-move-wash 0.38s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.square.last-move-to::after {
  background: var(--hl-to, rgba(214, 255, 184, 0.62));
  box-shadow: inset 0 0 22px var(--hl-inset, rgba(200, 230, 168, 0.32));
  animation: last-move-impact 0.55s cubic-bezier(0.16, 0.84, 0.32, 1);
}

.square.last-move-to::before {
  content: "";
  position: absolute;
  inset: 0;
  border: 3px solid var(--hl-ring, #d6ffb8);
  box-shadow:
    0 0 0 1px var(--hl-ring-soft, rgba(214, 255, 184, 0.55)),
    0 0 28px var(--hl-glow, rgba(57, 255, 20, 0.55));
  pointer-events: none;
  z-index: 3;
  animation: last-move-ripple 0.85s cubic-bezier(0.12, 0.8, 0.2, 1);
}

.square.last-move img,
.square.last-move-to img {
  position: relative;
  z-index: 4;
}

.square.last-move-to img {
  animation: last-move-piece 0.52s cubic-bezier(0.18, 0.9, 0.28, 1);
  transform-origin: center bottom;
  will-change: transform, filter;
}

html[data-highlights="wash"] .square.last-move-to::before,
html[data-highlights="soft"] .square.last-move-to::before {
  content: none;
  animation: none;
}

html[data-highlights="ring"] .square.last-move-from::after {
  background: transparent;
  animation: none;
}

html[data-highlights="ring"] .square.last-move-to::after {
  background: transparent;
  box-shadow: none;
  animation: none;
}

html[data-highlights="ring"] .square.last-move-to::before {
  animation: last-move-ring 0.7s cubic-bezier(0.16, 0.84, 0.32, 1);
  inset: 3px;
  border-width: 2px;
  box-shadow: 0 0 18px var(--hl-glow, rgba(45, 212, 191, 0.45));
  opacity: 1;
}

html[data-highlights="soft"] .square.highlight::after,
html[data-highlights="soft"] .square.last-move-from::after,
html[data-highlights="soft"] .square.last-move-to::after {
  opacity: 0.72;
}

html[data-highlights="soft"] .square.last-move-to img {
  animation: last-move-piece-soft 0.48s cubic-bezier(0.2, 0.85, 0.25, 1);
}

.square.last-move-deviation::after {
  background: rgba(228, 69, 79, 0.42);
}

@keyframes last-move-wash {
  0% {
    opacity: 0;
    transform: scale(0.92);
  }
  100% {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes last-move-impact {
  0% {
    opacity: 0;
    transform: scale(0.55);
  }
  45% {
    opacity: 1;
    transform: scale(1.04);
  }
  100% {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes last-move-ripple {
  0% {
    inset: 42%;
    opacity: 1;
    border-width: 4px;
    transform: scale(0.35);
  }
  55% {
    opacity: 0.85;
  }
  100% {
    inset: -2px;
    opacity: 0;
    border-width: 2px;
    transform: scale(1);
  }
}

@keyframes last-move-ring {
  0% {
    opacity: 0;
    transform: scale(0.7);
  }
  55% {
    opacity: 1;
    transform: scale(1.04);
  }
  100% {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes last-move-piece {
  0% {
    transform: translateY(10%) scale(0.62);
    filter: drop-shadow(0 0 16px var(--hl-glow, rgba(214, 255, 184, 0.95)));
  }
  48% {
    transform: translateY(-4%) scale(1.14);
    filter: drop-shadow(0 0 14px var(--hl-ring-soft, rgba(124, 255, 74, 0.7)));
  }
  72% {
    transform: translateY(1%) scale(0.97);
  }
  100% {
    transform: translateY(0) scale(1);
    filter: drop-shadow(0 2px 3px rgba(0, 0, 0, 0.35));
  }
}

@keyframes last-move-piece-soft {
  0% {
    transform: scale(0.82);
    filter: drop-shadow(0 0 8px var(--hl-glow, rgba(148, 163, 184, 0.55)));
  }
  60% {
    transform: scale(1.06);
  }
  100% {
    transform: scale(1);
    filter: drop-shadow(0 2px 3px rgba(0, 0, 0, 0.35));
  }
}

@media (prefers-reduced-motion: reduce) {
  .square.last-move-from::after,
  .square.last-move-to::after,
  .square.last-move-to img,
  .square.last-move-to::before {
    animation: none !important;
  }

  .square.last-move-to::before {
    content: none;
  }
}

.square.legal::before {
  content: "";
  position: absolute;
  width: 16%;
  height: 16%;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.22);
  pointer-events: none;
  z-index: 1;
}

.square.legal:has(img)::before {
  width: 78%;
  height: 78%;
  background: transparent;
  border: 3px solid rgba(0, 0, 0, 0.22);
}

.deviation-toast {
  width: min(100%, calc(100dvh - var(--trainer-chrome)));
  padding: 10px 14px;
  border: 1px solid #e4454f;
  background: #6f1822;
  color: #ffe8ea;
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-align: center;
}

.deviation-toast[hidden] {
  display: none;
}

#board-container.board-deviation #board {
  box-shadow: 0 12px 32px rgba(120, 20, 28, 0.4);
}

#board-controls {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  width: 100%;
  flex-shrink: 0;
  padding: 2px 0 0;
  border: 0;
  background: transparent;
}

main.opening-view #board-controls {
  justify-content: center;
  padding: 0;
}

#board-controls button,
#controls button,
.trainer-settings-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 8px 16px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--paper);
  color: var(--cream);
  font-family: var(--font);
  font-size: 0.8rem;
  font-weight: 650;
  letter-spacing: 0.03em;
  text-transform: none;
  cursor: pointer;
}

#board-controls button:disabled,
#controls button:disabled {
  opacity: 0.4;
  cursor: default;
}

#board-controls button:hover:not(:disabled),
#controls button:hover:not(:disabled),
.trainer-settings-toggle:hover {
  border-color: var(--cream-dim);
  background: var(--paper-2);
  color: var(--cream);
}

#board-controls button.trainer-mode.active,
#board-controls button.side-choice.active,
#board-controls button.tree-chip.active,
.trainer-settings-toggle[aria-expanded="true"] {
  border-color: var(--gold-btn-border);
  background: var(--gold-btn-from);
  color: var(--on-solid);
  box-shadow: none;
}

#board-controls button.trainer-mode.active:hover:not(:disabled),
#board-controls button.side-choice.active:hover:not(:disabled),
.trainer-settings-toggle[aria-expanded="true"]:hover {
  background: var(--gold-btn-from-hover);
  color: var(--on-solid);
}

.trainer-mode-row {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
}

.trainer-side-row {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.opening-view.is-theory #hint-button,
.opening-view.is-theory #reveal-button {
  display: none;
}

.opening-view.is-practice .nav-arrow-group,
.opening-view.is-timed .nav-arrow-group {
  display: none;
}

.timed-drill-hud {
  margin: 12px 0 4px;
  padding: 12px;
  border-radius: 12px;
  border: 1px solid color-mix(in srgb, var(--gold) 35%, var(--line));
  background:
    radial-gradient(ellipse 80% 70% at 10% 0%, color-mix(in srgb, var(--gold) 16%, transparent), transparent 60%),
    var(--bg-3);
}

.timed-drill-hud[hidden] {
  display: none;
}

.timed-drill-top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
}

.timed-drill-label {
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.timed-drill-top strong {
  font-size: 1.45rem;
  font-weight: 800;
  letter-spacing: -0.04em;
  color: var(--gold-bright);
  font-variant-numeric: tabular-nums;
}

.timed-drill-bar {
  margin-top: 8px;
  height: 8px;
  border-radius: 999px;
  overflow: hidden;
  background: color-mix(in srgb, var(--ink) 10%, transparent);
}

.timed-drill-bar i {
  display: block;
  height: 100%;
  width: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--gold-deep), var(--gold-bright));
  transition: width 0.08s linear;
}

.timed-drill-hud.is-urgent .timed-drill-top strong,
.timed-drill-hud.is-expired .timed-drill-top strong {
  color: #ff8f6b;
}

.timed-drill-hud.is-urgent .timed-drill-bar i,
.timed-drill-hud.is-expired .timed-drill-bar i {
  background: linear-gradient(90deg, #c2410c, #fb923c);
}

.timed-drill-note {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 0.78rem;
  line-height: 1.4;
}

.timed-seconds-row {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.timed-seconds-options {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 6px;
}

.timed-seconds-btn.is-on {
  border-color: var(--gold);
  color: var(--gold-bright);
  box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--gold) 35%, transparent);
}

.course-progress-wrap {
  margin: 10px 0 4px;
}

.course-progress-wrap[hidden] {
  display: none;
}

.course-progress-bar #course-progress-fill,
#course-progress-fill {
  width: 0%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--gold-deep), var(--gold-bright));
}

.course-progress-note {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 0.76rem;
}

.nav-arrow-group {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--paper);
}

#board-controls button.nav-arrow {
  width: 40px;
  min-width: 40px;
  height: 40px;
  min-height: 40px;
  padding: 0;
  display: grid;
  place-items: center;
  border: 0;
  color: var(--cream);
  background: transparent;
  box-shadow: none;
  overflow: visible;
}

#board-controls button.nav-arrow svg {
  display: block;
  width: 18px;
  height: 18px;
  overflow: visible;
  fill: currentColor;
}

#board-controls button.nav-arrow:hover:not(:disabled) {
  background: rgba(127, 127, 127, 0.18);
  color: var(--gold-bright);
}

#board-controls button.nav-arrow:disabled {
  opacity: 0.35;
}

#board-controls .nav-reset,
#board-controls .open-selected-game {
  min-height: 40px;
  padding: 8px 16px;
  border-radius: 999px;
}

#board-controls .open-selected-game {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--cream);
  font-family: var(--font);
  font-size: 0.8rem;
  font-weight: 650;
  letter-spacing: 0.03em;
  text-decoration: none;
}

#board-controls .open-selected-game:hover {
  border-color: var(--gold);
  color: var(--gold);
}

#board-controls .open-selected-game[hidden] {
  display: none;
}

.trainer-settings {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}

.trainer-settings-toggle {
  gap: 8px;
  width: 100%;
}

.trainer-settings-toggle svg {
  width: 16px;
  height: 16px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.trainer-settings-panel {
  margin-top: 10px;
}

#controls {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

#controls button {
  width: 100%;
}

.appearance-picker {
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
}

.appearance-label {
  margin: 0 0 8px;
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--cream-dim);
}

.appearance-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
  margin-bottom: 12px;
}

.appearance-swatch {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 6px;
  min-height: 0;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--paper);
  color: var(--cream);
  font-family: var(--font);
  font-size: 0.72rem;
  font-weight: 650;
  text-align: left;
  cursor: pointer;
}

.appearance-swatch.is-on {
  border-color: var(--gold-btn-border, var(--gold));
  box-shadow: inset 0 0 0 1px rgba(250, 204, 21, 0.25);
}

.appearance-swatch.is-locked {
  opacity: 0.72;
}

.appearance-note {
  margin: 2px 0 0;
  font-size: 0.78rem;
  line-height: 1.4;
  color: var(--muted);
}

.appearance-swatch img {
  width: 28px;
  height: 28px;
}

.appearance-swatch em {
  font-style: normal;
  font-size: 0.62rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--gold);
}

.appearance-board {
  display: grid;
  grid-template-columns: 1fr 1fr;
  width: 28px;
  height: 28px;
  overflow: hidden;
  border-radius: 4px;
}

.appearance-board i:nth-child(1),
.appearance-board i:nth-child(4) {
  background: var(--swatch-light);
}

.appearance-board i:nth-child(2),
.appearance-board i:nth-child(3) {
  background: var(--swatch-dark);
}

.appearance-arrow {
  position: relative;
  width: 28px;
  height: 28px;
  border-radius: 4px;
  background:
    linear-gradient(135deg, color-mix(in srgb, var(--swatch) 35%, #18181b), #27272a);
}

.appearance-arrow::after {
  content: "";
  position: absolute;
  left: 5px;
  right: 5px;
  top: 50%;
  height: 5px;
  border-radius: 999px;
  background: var(--swatch);
  box-shadow: 0 0 10px color-mix(in srgb, var(--swatch) 55%, transparent);
  transform: translateY(-50%) rotate(-18deg);
}

.appearance-highlight {
  position: relative;
  width: 28px;
  height: 28px;
  border-radius: 4px;
  background:
    linear-gradient(90deg, #eeeed2 50%, #769656 50%);
  overflow: hidden;
}

.appearance-highlight::after {
  content: "";
  position: absolute;
  inset: 0;
  background: color-mix(in srgb, var(--swatch) 55%, transparent);
}

.appearance-highlight[data-effect="ring"]::before {
  content: "";
  position: absolute;
  inset: 3px;
  border: 2px solid var(--swatch);
  border-radius: 2px;
  z-index: 1;
}

.appearance-highlight[data-effect="ring"]::after {
  background: transparent;
}

.studio-section .appearance-picker {
  margin-top: 4px;
  padding-top: 0;
  border: 0;
}

.line-progress-wrap,
#progress-panel,
#popularity-panel,
#player-repertoire-panel {
  margin-top: 16px;
  padding: 14px 14px 12px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--fill-subtle);
}

.practice-points-hud {
  display: grid;
  gap: 6px;
  margin-top: 12px;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--fill-subtle);
  color: var(--cream);
  transition: border-color 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.practice-points-hud.is-gain {
  border-color: color-mix(in srgb, var(--gold-bright) 70%, var(--line));
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--gold-bright) 35%, transparent);
}

.practice-points-hud.is-loss {
  border-color: color-mix(in srgb, var(--danger) 55%, var(--line));
}

.practice-points-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
}

.practice-points-label {
  font-size: 0.62rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gold);
}

.practice-points-live {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.62rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--gold-bright);
}

.practice-points-live::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 0 color-mix(in srgb, var(--gold) 70%, transparent);
  animation: practice-live-pulse 1.6s ease-out infinite;
}

.practice-points-score-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
}

#practice-points-value {
  font-size: 1.7rem;
  font-weight: 800;
  letter-spacing: -0.04em;
  font-variant-numeric: tabular-nums;
}

.practice-points-delta {
  font-size: 1.05rem;
  font-weight: 800;
  min-height: 1.1em;
}

.practice-points-delta[data-kind="up"] {
  color: var(--gold-bright);
  animation: practice-delta-pop 0.35s ease;
}

.practice-points-delta[data-kind="down"] {
  color: var(--danger);
  animation: practice-delta-pop 0.35s ease;
}

.practice-points-session,
.practice-points-rival {
  margin: 0;
  color: var(--muted);
  font-size: 0.8rem;
  line-height: 1.35;
}

.practice-points-streak {
  display: grid;
  gap: 4px;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}

.practice-points-streak b {
  color: var(--cream);
  font-variant-numeric: tabular-nums;
}

.practice-points-streak-bar {
  height: 6px;
  border-radius: 999px;
  background: var(--bg-3, var(--line));
  overflow: hidden;
}

.practice-points-streak-bar > i {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--gold), var(--gold-bright));
  transition: width 0.25s ease;
}

.practice-points-note {
  margin: 0;
  color: var(--muted);
  font-size: 0.82rem;
  line-height: 1.45;
}

.practice-points-hud a {
  color: var(--gold);
  font-size: 0.82rem;
  font-weight: 600;
  text-decoration: none;
}

.practice-points-hud a:hover {
  text-decoration: underline;
}

@keyframes practice-delta-pop {
  from { transform: scale(0.7); opacity: 0.2; }
  to { transform: scale(1); opacity: 1; }
}

@keyframes practice-live-pulse {
  0% { box-shadow: 0 0 0 0 color-mix(in srgb, var(--gold) 55%, transparent); }
  70% { box-shadow: 0 0 0 8px color-mix(in srgb, var(--gold) 0%, transparent); }
  100% { box-shadow: 0 0 0 0 color-mix(in srgb, var(--gold) 0%, transparent); }
}

@media (prefers-reduced-motion: reduce) {
  .practice-points-delta[data-kind],
  .practice-points-live::before {
    animation: none;
  }
}

.line-progress-label-row,
.progress-row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  font-size: 0.86rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--cream-dim);
}

.line-progress-bar {
  margin-top: 10px;
  height: 8px;
  background: var(--bg-3);
}

#line-progress-fill {
  width: 0;
  height: 100%;
  background: var(--gold-bright);
  transition: width 0.25s ease;
}

#progress-panel h3,
#popularity-panel h4,
#player-repertoire-panel h4 {
  margin: 0 0 12px;
  font-family: var(--serif);
  font-size: 1.28rem;
  font-weight: 600;
  color: var(--cream);
  letter-spacing: 0;
  text-transform: none;
}

.line-status-name {
  margin: 0 0 10px;
  color: var(--cream);
  font-size: 1.02rem;
  font-weight: 600;
  line-height: 1.4;
}

.line-status-badge {
  display: inline-flex;
  align-items: center;
  margin: 0 0 10px;
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.line-status-badge.is-mastered {
  border-color: var(--gold);
  color: var(--gold-bright);
  background: rgba(127, 127, 127, 0.14);
}

.line-status-badge.is-pending {
  color: var(--cream-dim);
}

.line-status-note {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.55;
}

.progress-row {
  padding: 9px 0;
  border-bottom: 1px solid var(--line);
}

.progress-row:last-child { border-bottom: none; }

.progress-row strong {
  color: var(--gold-bright);
  font-size: 1rem;
}

#stats-loader {
  margin-bottom: 10px;
  font-size: 0.92rem;
  line-height: 1.45;
  color: var(--cream-dim);
}

#stats-display,
.stats-hud {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
}

.stat-badge {
  --stat-pct: 0%;
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 0;
  padding: 12px 12px 11px;
  text-align: left;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--bg-3);
}

.stat-kicker {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.stat-kicker::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: currentColor;
  flex-shrink: 0;
}

.stat-value {
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums;
  line-height: 1;
  color: var(--cream);
}

.stat-bar {
  display: block;
  height: 5px;
  overflow: hidden;
  border-radius: 999px;
  background: rgba(0, 0, 0, 0.22);
}

.stat-bar-fill {
  display: block;
  width: var(--stat-pct);
  height: 100%;
  border-radius: 999px;
  transition: width 0.28s ease;
}

.stat-badge.is-white .stat-kicker { color: var(--stat-white); }
.stat-badge.is-white .stat-bar-fill { background: var(--stat-white); }

.stat-badge.is-draw .stat-kicker { color: var(--data-draw); }
.stat-badge.is-draw .stat-bar-fill { background: var(--data-draw-fill); }

.stat-badge.is-black .stat-kicker { color: var(--cream-dim); }
.stat-badge.is-black .stat-bar-fill { background: var(--cream); }

.color-toggle {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4px;
  margin-bottom: 12px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--bg-3);
}

.color-toggle .tree-chip {
  padding: 9px 10px;
  border: 0;
  border-radius: 9px;
  background: transparent;
  color: var(--cream-dim);
  font-family: var(--font);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: none;
  cursor: pointer;
}

.color-toggle .tree-chip:hover {
  color: var(--cream);
}

.color-toggle .tree-chip.active {
  background: var(--gold);
  color: var(--on-gold);
  border-color: transparent;
  box-shadow: none;
}

.book-mode-toggle {
  margin: 0 0 14px;
}

.recent-games-lead {
  margin: 0 0 12px;
  color: var(--muted);
  font-size: 0.88rem;
  line-height: 1.5;
}

.recent-games-list {
  list-style: none;
  margin: 0;
  padding: 0 0 8px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  max-height: none;
  overflow: visible;
  scrollbar-width: thin;
}

.recent-scan-size {
  margin: 8px 0 0;
  flex-wrap: wrap;
}

.recent-color-filter {
  margin: 8px 0 0;
}

.opening-scan-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 4.4rem;
  gap: 10px 16px;
  margin: 14px 0 4px;
  padding: 0 10px 8px;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.opening-scan-head span:last-child {
  text-align: right;
}

.opening-scan-head[hidden] {
  display: none;
}

.opening-stat-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 10px 16px;
  align-items: center;
  width: 100%;
  margin: 0;
  padding: 10px 10px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--cream);
  font-family: var(--font);
  text-align: left;
  cursor: pointer;
}

.opening-stat-row:hover,
.opening-stat-row.is-active {
  background: rgba(127, 127, 127, 0.12);
}

.opening-stat-main {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.opening-stat-row strong {
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  overflow: hidden;
  font-size: 0.86rem;
  font-weight: 650;
  line-height: 1.35;
}

.opening-stat-meta {
  color: var(--muted);
  font-size: 0.75rem;
  font-variant-numeric: tabular-nums;
  line-height: 1.3;
}

.opening-stat-rate {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 5px;
  min-width: 4.4rem;
}

.opening-stat-pct {
  color: var(--cream);
  font-size: 1.02rem;
  font-weight: 750;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.03em;
  line-height: 1;
}

.opening-stat-row.is-low .opening-stat-pct {
  color: #d4a39e;
}

.opening-stat-row.is-high .opening-stat-pct {
  color: var(--data-win);
}

.opening-stat-bar {
  width: 64px;
  height: 3px;
  border-radius: 99px;
  background: rgba(127, 127, 127, 0.22);
  overflow: hidden;
}

.opening-stat-bar > span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--gold);
}

.opening-stat-row.is-low .opening-stat-bar > span {
  background: #c07a74;
}

.opening-stat-item {
  display: flex;
  flex-direction: column;
}

.opening-stat-row.has-games .opening-stat-main strong::after {
  display: none;
}

.opening-game-list {
  list-style: none;
  margin: 0;
  padding: 0 4px 2px 10px;
  display: flex;
  flex-direction: column;
  gap: 1px;
  border-left: 1px solid var(--line);
  margin-left: 10px;
}

.opening-game-row {
  display: grid;
  grid-template-columns: 4.6rem minmax(0, 1fr);
  gap: 8px;
  align-items: baseline;
  width: 100%;
  margin: 0;
  padding: 7px 8px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--cream);
  font-family: var(--font);
  text-align: left;
  cursor: pointer;
}

.opening-game-row:hover,
.opening-game-row.is-active {
  background: rgba(127, 127, 127, 0.12);
}

.opening-game-result {
  font-size: 0.72rem;
  font-weight: 750;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
}

.opening-game-row.is-win .opening-game-result {
  color: var(--data-win);
}

.opening-game-row.is-loss .opening-game-result {
  color: #d4a39e;
}

.opening-game-row.is-draw .opening-game-result {
  color: var(--gold);
}

.opening-game-detail {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: var(--muted);
  font-size: 0.75rem;
  font-variant-numeric: tabular-nums;
}

#recent-games-status {
  margin: 12px 0 0;
  color: var(--cream);
  font-size: 0.84rem;
  font-variant-numeric: tabular-nums;
  line-height: 1.45;
}

#recent-games-panel[hidden] {
  display: none !important;
}

.guest-search-gate {
  margin: -4px 0 12px;
  padding: 12px 14px;
  border: 1px solid var(--line-strong);
  border-radius: 12px;
  background: rgba(127, 127, 127, 0.12);
  color: var(--cream);
  font-size: 0.92rem;
  line-height: 1.55;
}

.guest-search-gate[hidden] {
  display: none;
}

.guest-search-gate a {
  color: var(--gold-bright);
  font-weight: 700;
}

.lichess-user-form {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 12px;
}

.lichess-user-form input {
  flex: 1;
  min-width: 0;
  height: 28px;
  padding: 0 8px;
  border: 1px solid var(--line);
  background: var(--bg-3);
  color: var(--cream);
  font-family: var(--font);
  font-size: 0.78rem;
  line-height: 1;
  border-radius: 6px;
}

.lichess-user-form button {
  flex: 0 0 auto;
  height: 28px;
  min-width: 0;
  min-height: 0;
  padding: 0 9px;
  border: 1px solid var(--gold);
  background: var(--gold);
  color: var(--on-gold);
  font-family: var(--font);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  line-height: 1;
  text-transform: uppercase;
  border-radius: 6px;
  cursor: pointer;
}

#lichess-username-form button[type="submit"],
#recent-games-form button[type="submit"] {
  min-width: 0;
  width: auto;
}

#player-moves-status {
  margin: 0 0 14px;
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--cream-dim);
}

.player-load-progress {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 12px;
}

.player-load-progress[hidden] {
  display: none;
}

.player-load-track {
  flex: 1;
  height: 10px;
  border: 1px solid var(--line-strong);
  background: rgba(0, 0, 0, 0.35);
  overflow: hidden;
}

.player-load-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--gold-deep), var(--gold), var(--gold-bright));
  transition: width 0.25s ease;
}

#player-load-label {
  min-width: 3.2em;
  text-align: right;
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--gold-bright);
}

#player-moves-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
  max-height: 22rem;
  overflow-y: auto;
}

#player-moves-list li {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  padding: 12px 14px;
  border: 1px solid var(--line);
  background: var(--bg-3);
  color: var(--cream);
  font-size: 1rem;
  line-height: 1.45;
}

#player-moves-list strong {
  color: var(--gold-bright);
}

.player-games-heading {
  margin: 16px 0 8px;
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--gold);
  font-weight: 700;
}

.player-games-list[hidden],
.player-games-heading[hidden] {
  display: none !important;
}

.player-games-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-height: 16rem;
  overflow-y: auto;
}

.player-games-list li {
  margin: 0;
  padding: 0;
}

.player-games-list a {
  display: block;
  padding: 10px 12px;
  border: 1px solid var(--line);
  background: var(--bg-3);
  color: var(--cream);
  text-decoration: none;
  font-size: 0.88rem;
  line-height: 1.4;
}

.player-games-list a:hover {
  border-color: var(--gold);
  color: var(--gold-bright);
}

main.tree-view #player-moves-list li {
  cursor: pointer;
}

main.tree-view #player-moves-list li:hover {
  border-color: var(--gold);
  background: rgba(127, 127, 127, 0.12);
}

.tree-fen-form {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 12px;
}

.tree-fen-form input {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--line);
  background: var(--bg-3);
  color: var(--cream);
  font-family: ui-monospace, Consolas, monospace;
  font-size: 0.78rem;
}

.tree-fen-form button {
  align-self: flex-start;
  padding: 8px 12px;
  border: 1px solid var(--line-strong);
  background: var(--bg-3);
  color: var(--cream);
  font-family: var(--font);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  cursor: pointer;
}

.neon-text {
  color: inherit;
  text-shadow: none;
  animation: none;
}

.studio-info-scroll {
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  padding-right: 2px;
  scrollbar-width: thin;
  scrollbar-color: rgba(161, 161, 170, 0.45) transparent;
}

.studio-section {
  margin-top: 14px;
  padding: 14px 14px 12px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--fill-subtle);
}

.studio-section h3 {
  margin: 0 0 10px;
  font-family: var(--font);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.studio-label {
  display: block;
  margin: 10px 0 6px;
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--cream-dim);
}

.studio-section > .studio-label:first-of-type {
  margin-top: 0;
}

#course-title,
#line-name,
#move-comment,
#pgn-import {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--bg-3);
  color: var(--cream);
  font-family: var(--font);
}

.studio-cover {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-top: 4px;
}

.studio-cover-frame {
  position: relative;
  width: 88px;
  height: 88px;
  flex: 0 0 auto;
  overflow: hidden;
  border-radius: 12px;
  border: 1px solid var(--line);
  background:
    linear-gradient(145deg, color-mix(in srgb, var(--gold) 10%, transparent), transparent 55%),
    var(--bg-3);
}

.studio-cover-frame.is-empty {
  border-style: dashed;
  border-color: color-mix(in srgb, var(--line-strong) 70%, transparent);
  background:
    radial-gradient(circle at 30% 28%, color-mix(in srgb, var(--gold) 14%, transparent), transparent 42%),
    linear-gradient(160deg, var(--bg-3), var(--bg-2));
}

#course-cover-preview {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  background: transparent;
  border: 0;
  border-radius: 0;
}

#course-cover-preview[hidden] {
  display: none;
}

.studio-cover-empty {
  position: absolute;
  inset: 0;
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  color: var(--muted);
  pointer-events: none;
}

.studio-cover-frame.is-empty .studio-cover-empty {
  display: flex;
}

.studio-cover-empty svg {
  width: 28px;
  height: 28px;
  opacity: 0.72;
}

.studio-cover-empty span {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.studio-cover-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.studio-cover-hint {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 0.8rem;
  line-height: 1.4;
}

.studio-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 0 0 4px;
}

.studio-tag-chip {
  display: inline-flex;
  align-items: center;
  gap: 0;
  margin: 0;
  cursor: pointer;
  user-select: none;
}

.studio-tag-chip input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.studio-tag-chip span {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--bg-3);
  color: var(--cream-dim);
  font-size: 0.74rem;
  font-weight: 650;
  letter-spacing: 0.01em;
  transition: border-color 0.15s ease, color 0.15s ease, background 0.15s ease;
}

.studio-tag-chip input:checked + span {
  border-color: color-mix(in srgb, var(--gold) 55%, var(--line));
  background: color-mix(in srgb, var(--gold) 14%, var(--bg-3));
  color: var(--gold-bright);
}

.studio-tag-chip input:focus-visible + span {
  outline: 2px solid color-mix(in srgb, var(--gold) 55%, transparent);
  outline-offset: 2px;
}

.studio-unlimited-promo {
  position: relative;
  margin: 18px 0 4px;
  padding: 14px 14px 16px;
  border-radius: 14px;
  border: 1px solid color-mix(in srgb, var(--gold) 42%, var(--line));
  background:
    radial-gradient(ellipse 90% 70% at 12% 0%, color-mix(in srgb, var(--gold) 18%, transparent), transparent 55%),
    linear-gradient(165deg, color-mix(in srgb, var(--gold) 8%, var(--bg-3)), var(--bg-3));
  box-shadow:
    inset 0 1px 0 color-mix(in srgb, var(--gold) 22%, transparent),
    0 0 0 1px color-mix(in srgb, var(--gold) 12%, transparent),
    0 10px 28px rgba(0, 0, 0, 0.18);
  overflow: hidden;
  animation: studio-unlimited-in 0.55s cubic-bezier(0.22, 1, 0.36, 1) both;
}

.studio-unlimited-promo::after {
  content: "";
  position: absolute;
  inset: -40% auto auto -20%;
  width: 120px;
  height: 120px;
  border-radius: 50%;
  background: color-mix(in srgb, var(--gold) 16%, transparent);
  filter: blur(18px);
  pointer-events: none;
  animation: studio-unlimited-glow 2.8s ease-in-out infinite;
}

.studio-unlimited-promo-top {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: 10px;
}

.studio-unlimited-badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 8px;
  border-radius: 999px;
  background: var(--gold);
  color: var(--on-gold);
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  animation: studio-unlimited-badge 1.8s ease-in-out infinite;
}

.studio-unlimited-save {
  color: var(--gold-bright);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.studio-unlimited-promo h3 {
  position: relative;
  z-index: 1;
  margin: 0 0 6px;
  font-size: 1.05rem;
  font-weight: 750;
  letter-spacing: -0.03em;
  color: var(--cream);
}

.studio-unlimited-lead {
  position: relative;
  z-index: 1;
  margin: 0 0 12px;
  color: var(--muted);
  font-size: 0.82rem;
  line-height: 1.45;
}

.studio-unlimited-price {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin: 0 0 6px;
}

.studio-unlimited-was {
  width: fit-content;
  color: var(--muted);
  font-size: 0.86rem;
  font-weight: 600;
  text-decoration: line-through;
  text-decoration-thickness: 1.5px;
  opacity: 0.78;
}

.studio-unlimited-was-inline {
  text-decoration: line-through;
  text-decoration-thickness: 1.5px;
  opacity: 0.78;
}

.studio-unlimited-now {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
}

.studio-unlimited-now strong {
  color: var(--gold-bright);
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  text-shadow: 0 0 18px color-mix(in srgb, var(--gold) 35%, transparent);
}

.studio-unlimited-now span {
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.studio-unlimited-then {
  position: relative;
  z-index: 1;
  margin: 0 0 14px;
  color: var(--muted);
  font-size: 0.78rem;
  line-height: 1.4;
}

.studio-unlimited-cta {
  position: relative;
  z-index: 1;
  width: 100%;
  justify-content: center;
  text-align: center;
}

@keyframes studio-unlimited-in {
  from {
    opacity: 0;
    transform: translateY(10px) scale(0.98);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes studio-unlimited-glow {
  0%, 100% { opacity: 0.45; transform: translate(0, 0) scale(1); }
  50% { opacity: 0.85; transform: translate(18px, 10px) scale(1.12); }
}

@keyframes studio-unlimited-badge {
  0%, 100% { box-shadow: 0 0 0 0 color-mix(in srgb, var(--gold) 0%, transparent); }
  50% { box-shadow: 0 0 0 6px color-mix(in srgb, var(--gold) 18%, transparent); }
}

@media (prefers-reduced-motion: reduce) {
  .studio-unlimited-promo,
  .studio-unlimited-promo::after,
  .studio-unlimited-badge {
    animation: none;
  }
}

#pgn-import {
  min-height: 88px;
  resize: vertical;
  font-size: 0.86rem;
  line-height: 1.45;
}

.studio-pgn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 8px;
}

#studio-status {
  margin: 14px 0 4px;
  color: var(--cream-dim);
  font-size: 0.86rem;
  line-height: 1.4;
}

#studio-status:empty {
  display: none;
}

.studio-actions {
  display: flex;
  flex-wrap: wrap;
  flex: 0 0 auto;
  gap: 8px;
  margin-top: 10px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
}

#publish-course {
  display: inline-flex !important;
}

.studio-help {
  margin: 2px 0 0;
  color: var(--muted);
  font-size: 0.84rem;
  text-align: center;
}

.studio-side-row {
  display: flex;
  gap: 8px;
}

.studio-side-row .side-choice {
  flex: 1;
  padding: 10px 12px;
  border: 1px solid var(--line-strong);
  background: var(--bg-3);
  color: var(--cream);
  font-family: var(--font);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  cursor: pointer;
}

.studio-side-row .side-choice.active {
  border-color: color-mix(in srgb, var(--gold) 55%, var(--line));
  background: color-mix(in srgb, var(--gold) 16%, transparent);
  color: var(--gold-bright);
}

.course-studio #info-content {
  flex: 0 0 auto;
  min-height: 0;
  padding: 0 2px 10px;
  font-size: 0.95rem;
  line-height: 1.5;
}

.course-studio #info-content:empty {
  display: none;
  padding: 0;
}

.course-studio .studio-tree-panel {
  overflow: hidden;
  min-height: 0;
  padding: 0;
}

/* Line navigation lives at the foot of the right-hand panel in the course
   builder. It docks under the move tree and never floats over the board. */
main.course-studio #line-menu-container #board-controls {
  flex: 0 0 auto;
  display: flex;
  justify-content: center;
  width: 100%;
  padding: 12px 16px 14px;
  border-top: 1px solid var(--line);
  background: var(--paper);
}

main.course-studio #line-menu-container #board-controls .nav-arrow-group {
  margin: 0 auto;
}

main.course-studio #line-menu-container .studio-tree-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex: 0 0 auto;
  margin: 0;
  padding: 14px 16px 13px;
  border-bottom: 1px solid var(--line);
}

main.course-studio #line-menu-container .studio-tree-head h2 {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0;
  padding: 0;
  border: 0;
  font-family: var(--font);
  font-size: 0.72rem;
  font-weight: 400;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

main.course-studio #line-menu-container .line-menu-count {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.6rem;
  padding: 3px 8px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--fill-subtle);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: none;
  color: var(--cream-dim);
  font-variant-numeric: tabular-nums;
}

main.course-studio #line-menu-container .studio-tree-subhead {
  margin-top: 0;
  border-top: 1px solid var(--line);
}

.studio-add-line {
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--fill-subtle);
  color: var(--cream);
  font-family: var(--font);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  cursor: pointer;
}

.studio-add-line:hover {
  border-color: color-mix(in srgb, var(--gold) 48%, var(--line));
  color: var(--gold-bright);
}

.course-studio #studio-move-tree {
  min-height: 0;
}

#studio-line-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  flex: 0 1 auto;
  gap: 0;
  max-height: 38%;
  overflow-y: auto;
  counter-reset: line-n;
  scrollbar-width: thin;
  scrollbar-color: rgba(161, 161, 170, 0.45) transparent;
}

#studio-line-list li {
  display: grid;
  grid-template-columns: 1.55rem minmax(0, 1fr) auto auto;
  align-items: center;
  column-gap: 8px;
  margin: 0;
  padding: 0 10px 0 16px;
  border-bottom: 1px solid var(--line);
}

#studio-line-list li::before {
  counter-increment: line-n;
  content: counter(line-n, decimal-leading-zero);
  font-size: 0.66rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

#studio-line-list .studio-line-pick {
  min-width: 0;
  padding: 11px 0;
  border: 0;
  background: transparent;
  color: var(--cream);
  font-family: var(--font);
  font-size: 0.9rem;
  font-weight: 500;
  line-height: 1.35;
  text-align: left;
  cursor: pointer;
}

#studio-line-list .studio-line-name {
  display: block;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

#studio-line-list .studio-line-meta {
  font-size: 0.66rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

#studio-line-list li:hover {
  background: var(--hover-fill);
}

#studio-line-list li.active {
  background: color-mix(in srgb, var(--gold) 12%, transparent);
  box-shadow: inset 3px 0 0 var(--gold);
}

#studio-line-list li.active::before {
  color: var(--gold-bright);
}

#studio-line-list li.active .studio-line-pick {
  color: var(--cream);
}

#studio-line-list .studio-line-delete {
  flex: 0 0 auto;
  width: 28px;
  height: 28px;
  padding: 0;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--muted);
  font-size: 1.15rem;
  line-height: 1;
  cursor: pointer;
}

#studio-line-list .studio-line-delete:hover {
  background: rgba(228, 69, 79, 0.12);
  color: var(--danger);
}

.course-studio .tree-start {
  width: auto;
  margin: 10px 14px 6px;
  padding: 8px 12px;
  border-radius: 8px;
  font-size: 0.72rem;
}

.course-studio .move-tree {
  padding: 4px 14px 12px;
}

.tree-start {
  display: block;
  width: 100%;
  margin-bottom: 12px;
  padding: 10px 12px;
  border: 1px dashed var(--line-strong);
  border-radius: 10px;
  background: transparent;
  color: var(--cream-dim);
  font-family: var(--font);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
  text-align: left;
}

.tree-start:hover,
.tree-start.current {
  border-style: solid;
  border-color: var(--gold-bright);
  color: var(--gold-bright);
  background: rgba(127, 127, 127, 0.12);
}

.move-tree {
  flex: 1;
  overflow-y: auto;
  padding: 4px 2px 8px;
  font-variant-numeric: tabular-nums;
}

.tree-empty {
  margin: 12px 0 0;
  color: var(--muted);
  line-height: 1.6;
}

.tree-line,
.tree-variation {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 6px;
}

.tree-variation {
  flex: 1 0 100%;
  margin: 4px 0 6px 8px;
  padding: 8px 8px 8px 12px;
  border-left: 2px solid var(--gold);
  background: rgba(127, 127, 127, 0.06);
  border-radius: 0 10px 10px 0;
}

.tree-token {
  display: inline-flex;
  align-items: baseline;
  gap: 3px;
}

.tree-ply {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 700;
}

.tree-san {
  padding: 3px 8px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--cream);
  font-family: var(--font);
  font-size: 0.98rem;
  font-weight: 700;
  cursor: pointer;
}

.tree-san:hover {
  background: var(--hover-fill);
}

.tree-san.on-path {
  color: var(--gold-bright);
}

.tree-san.current {
  background: var(--gold);
  color: var(--on-gold);
}

.tree-san.sideline {
  font-style: italic;
  color: var(--cream-dim);
}

.tree-san.sideline.current,
.tree-san.sideline.on-path {
  font-style: normal;
}

.tree-san.has-comment::after {
  content: "*";
  margin-left: 2px;
  color: var(--gold-bright);
}

.tree-move-menu {
  position: fixed;
  z-index: 80;
  min-width: 11.5rem;
  padding: 6px;
  border: 1px solid var(--line-strong);
  border-radius: 10px;
  background: var(--bg-2);
  box-shadow: 0 16px 40px var(--shadow);
}

.tree-move-menu[hidden] {
  display: none;
}

.tree-move-menu button {
  display: block;
  width: 100%;
  padding: 8px 10px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--cream);
  font-family: var(--font);
  font-size: 0.88rem;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
}

.tree-move-menu button:hover {
  background: rgba(127, 127, 127, 0.16);
  color: var(--gold-bright);
}

.course-studio.is-training .studio-edit-only {
  display: none !important;
}

.course-studio #edit-studio {
  display: none;
}

.course-studio.is-training #edit-studio {
  display: inline-flex;
}

.course-studio.is-training #train-studio {
  display: none;
}

.course-studio #board.is-dragging {
  cursor: grabbing;
}

@media (max-width: 1180px) {
  main.opening-view,
  main.tree-view,
  main.course-studio {
    grid-template-columns: 1fr;
    min-height: 0;
    width: 100%;
    max-width: 100%;
    min-width: 0;
    --trainer-chrome: 10.25rem;
    --trainer-side-max: none;
  }

  main.opening-view {
    flex: none;
    gap: 12px;
    padding: 0 0 8px;
    width: 100%;
    display: grid;
    grid-template-columns: 1fr;
    grid-template-rows: none;
    --trainer-rail: minmax(0, 1fr);
  }

  main.opening-view #board-container,
  main.tree-view #board-container {
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 8px 8px 4px;
    gap: 4px;
    width: 100%;
    max-width: 100%;
    min-width: 0;
  }

  main.opening-view #info-box,
  main.opening-view #board-stage,
  main.opening-view #line-menu-container,
  main.tree-view #info-box,
  main.tree-view #board-stage,
  main.tree-view #line-menu-container {
    grid-column: auto;
    grid-row: auto;
    width: auto;
    height: auto;
    max-height: none;
  }

  main.tree-view .tree-side-scroll {
    flex: none;
    overflow: visible;
  }

  #info-box,
  #line-menu-container {
    max-height: none;
  }

  main.opening-view .trainer-side-scroll {
    flex: none;
    overflow: visible;
  }

  #board-container {
    order: -1;
  }

  main.opening-view #board-container {
    justify-content: center;
    padding: 8px 8px 4px;
    gap: 4px;
  }

  #info-box,
  #line-menu-container {
    max-height: none;
  }

  #board-container {
    order: -1;
  }

  main.course-studio #info-box {
    overflow: visible;
  }

  .studio-info-scroll {
    overflow: visible;
    flex: none;
  }

  #studio-line-list {
    max-height: none;
  }
}

@media (pointer: coarse) {
  .square img {
    pointer-events: none;
    touch-action: manipulation;
  }

  #board {
    -webkit-user-select: none;
    user-select: none;
  }

  .square.legal::before {
    width: 24%;
    height: 24%;
  }

  .square.legal:has(img)::before {
    width: 86%;
    height: 86%;
  }
}

@media (max-width: 760px) {
  body.training-page .page-shell {
    width: calc(100% - 12px);
    max-width: 100%;
    padding: 4px 0 8px;
    overflow-x: hidden;
  }

  main.opening-view,
  main.tree-view,
  main.course-studio {
    gap: 10px;
    padding: 0 0 12px;
    width: 100%;
    max-width: 100%;
    min-width: 0;
  }

  #board-stage {
    width: 100%;
    max-width: 100%;
  }

  #board {
    width: 100%;
    max-width: 100%;
  }

  #info-box,
  #line-menu-container {
    padding: 16px 14px;
  }

  main.opening-view #info-box,
  main.opening-view #line-menu-container,
  main.tree-view #info-box,
  main.tree-view #line-menu-container {
    padding: 0;
  }

  #board-container {
    padding: 8px 6px 10px;
    gap: 8px;
  }

  #board-stage {
    width: 100%;
    max-width: min(100%, 560px);
    margin-inline: auto;
  }

  #board {
    border: 0;
    box-shadow: 0 8px 22px rgba(0, 0, 0, 0.32);
  }

  .square img {
    pointer-events: none;
  }

  #board-controls {
    gap: 6px;
  }

  #board-controls button,
  #controls button,
  .trainer-settings-toggle {
    min-height: 44px;
    padding: 10px 12px;
  }

  main.opening-view .trainer-session .trainer-mode,
  main.opening-view .trainer-session .side-choice,
  main.opening-view .trainer-session-actions button {
    min-height: 36px;
  }

  .nav-arrow-group .nav-arrow {
    min-width: 44px;
  }

  #board-controls button.nav-arrow,
  main.opening-view .line-menu-head .nav-arrow {
    width: 44px;
    min-width: 44px;
    height: 44px;
    min-height: 44px;
  }

  .lichess-user-form {
    flex-direction: row;
    align-items: center;
  }

  .lichess-user-form input,
  #course-title,
  #line-name,
  #move-comment,
  #pgn-import {
    min-height: 44px;
    font-size: 16px;
  }

  .lichess-user-form input {
    height: 36px;
    min-height: 36px;
  }

  .lichess-user-form button {
    width: auto;
    height: 36px;
    min-height: 32px;
    padding: 0 10px;
    font-size: 0.7rem;
  }

  #line-menu li,
  #tree-move-list li,
  #book-moves-list li,
  #studio-line-list .studio-line-pick {
    min-height: 44px;
  }

  #stats-display,
  .stats-hud {
    gap: 6px;
  }

  .stat-badge {
    padding: 10px 8px 9px;
  }

  .stat-value {
    font-size: 1.02rem;
  }
}