/* Lingo Cards — statistics, settings, dialogs and toasts */

/* Stats */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 12px; margin-bottom: 28px; min-width: 0; }
.stat-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
}
.stat-card .stat-label { font-size: 12px; color: var(--ink-muted); text-transform: uppercase; letter-spacing: .06em; }
.stat-card .stat-value { font-family: var(--font-serif); font-size: 30px; font-weight: 500; margin-top: 4px; letter-spacing: -0.01em; }
.stat-card .stat-sub { font-size: 12px; color: var(--ink-subtle); margin-top: 2px; }

.stats-block {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  margin-bottom: 16px;
}
.stats-block h3 { margin: 0 0 14px; font-family: var(--font-serif); font-weight: 500; font-size: 17px; }
.bar-chart {
  display: grid; grid-auto-flow: column; grid-auto-columns: 1fr; gap: 4px;
  align-items: end; height: 140px;
}
.bar-chart .bar {
  background: var(--accent-soft);
  border-radius: 4px 4px 0 0;
  position: relative;
  min-height: 2px;
  transition: background .15s;
}
.bar-chart .bar:hover { background: var(--accent); }
.bar-chart .bar::after {
  content: attr(data-day);
  position: absolute; bottom: -18px; left: 50%; transform: translateX(-50%);
  font-size: 12px; color: var(--ink-faint);
}
.bar-chart .bar .tip {
  position: absolute; bottom: 100%; left: 50%; transform: translateX(-50%) translateY(-4px);
  background: var(--ink); color: var(--bg);
  padding: 3px 8px; border-radius: 4px; font-size: 12px;
  opacity: 0; pointer-events: none; transition: opacity .12s; white-space: nowrap;
}
.bar-chart .bar:hover .tip { opacity: 1; }

/* Settings */
.settings-route-panel[hidden] { display: none !important; }

/* P20: Settings home title */
.settings-home-title {
  font-family: var(--font-serif);
  font-size: 1.6rem;
  font-weight: 600;
  margin: 0 0 20px;
  letter-spacing: -0.01em;
}

/* P20: Settings route list — groups and rows */
.settings-route-list {
  display: grid;
  gap: 16px;
  max-width: 680px;
}
.settings-group {
  display: grid;
  gap: 0;
}
.settings-group-label {
  display: block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--ink-muted);
  padding: 0 4px 6px;
}
.settings-route-btn {
  display: grid;
  grid-template-columns: 36px 1fr 20px;
  align-items: center;
  gap: 12px;
  min-height: 56px;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 13px;
  background: var(--panel);
  color: var(--ink);
  font: inherit;
  text-align: left;
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s;
  margin-bottom: 6px;
}
.settings-route-btn:last-child { margin-bottom: 0; }
.settings-route-btn:hover { background: var(--bg-elev); border-color: var(--border-strong); }
.settings-route-btn:active { background: var(--accent-soft); }
.settings-route-btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.route-icon {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 9px;
  background: var(--accent-soft);
  color: var(--accent);
}
.route-icon svg { width: 20px; height: 20px; }
.route-label-wrap {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}
.route-label {
  font-weight: 600;
  font-size: 14.5px;
  line-height: 1.3;
}
.route-summary {
  font-size: 12.5px;
  color: var(--ink-muted);
  line-height: 1.3;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.route-chevron {
  display: grid;
  place-items: center;
  color: var(--ink-faint);
}
.route-chevron svg { width: 16px; height: 16px; }

/* P20: Settings home footer */
.settings-home-footer {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  margin-top: 24px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  color: var(--ink-faint);
  font-size: 12px;
}

.settings-route-panel > h2 {
  margin: 0 0 16px;
  font-size: 1.25rem;
}
.view-settings { overscroll-behavior-x: auto; }

.settings-title-row {
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.settings-top-back-btn {
  margin-right: auto;
  padding-left: 2px;
}
.app-build-meta {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 1px;
  margin-left: auto;
  color: var(--ink-subtle);
  font-size: 8px;
  line-height: 1.2;
  white-space: nowrap;
  text-align: right;
  font-variant-numeric: tabular-nums;
}
.app-build-meta time { font-size: 8px; }
.settings-grid { display: grid; gap: 14px; max-width: 720px; }
.settings-block {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  margin-bottom: 16px;
  max-width: 640px;
}
.settings-block h3 { margin: 0 0 14px; font-family: var(--font-serif); font-weight: 500; font-size: 17px; }
.settings-row {
  display: grid; grid-template-columns: 1fr 200px; gap: 16px;
  padding: 10px 0;
  border-top: 1px solid var(--border);
  align-items: center;
}
.settings-row:first-of-type { border-top: none; }
.settings-row.toggle { grid-template-columns: 1fr auto; }
.settings-row.with-hint { align-items: start; padding: 12px 0; }
.settings-row.with-hint > div:first-child { display: flex; flex-direction: column; gap: 2px; }
.settings-row .row-hint {
  color: var(--ink-faint);
  font-size: 12px;
  line-height: 1.4;
  max-width: 380px;
}
.settings-row label { color: var(--ink); font-size: 13.5px; }
.settings-row input[type="text"],
.settings-row input[type="number"],
.settings-row select {
  background: var(--bg-elev);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  width: 100%;
}
.settings-row input[type="checkbox"] { width: 18px; height: 18px; accent-color: var(--accent); }
.tts-rate-control { display: flex; flex-direction: column; gap: 10px; min-width: 0; }
.tts-rate-slider-line { display: grid; grid-template-columns: minmax(0, 1fr) 48px; gap: 10px; align-items: center; }
.tts-rate-slider-line input[type="range"] {
  width: 100%;
  min-width: 0;
  accent-color: var(--accent);
  cursor: pointer;
}
.tts-rate-slider-line output {
  color: var(--ink);
  font-size: 13px;
  font-variant-numeric: tabular-nums;
  text-align: right;
}
.tts-preview-btn { justify-self: start; min-height: 36px; }
.study-mode-picker { position: relative; min-width: 0; }
.study-mode-trigger {
  box-sizing: border-box;
  display: flex;
  width: 100%;
  min-height: 36px;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 6px 10px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  background: var(--bg-elev);
  color: var(--ink);
  font: inherit;
  text-align: left;
  cursor: pointer;
}
.study-mode-trigger:focus-visible,
.study-mode-menu label:focus-within { outline: 2px solid var(--accent); outline-offset: 2px; }
.study-mode-chevron { flex: none; color: var(--ink-muted); transition: transform 160ms cubic-bezier(.25, 1, .5, 1); }
.study-mode-trigger[aria-expanded="true"] .study-mode-chevron { transform: rotate(180deg); }
.study-mode-menu {
  position: absolute;
  z-index: 30;
  top: calc(100% + 5px);
  right: 0;
  box-sizing: border-box;
  display: grid;
  width: 100%;
  min-width: 180px;
  overflow: hidden;
  border: 1px solid var(--border-strong);
  border-radius: 10px;
  background: var(--panel);
  box-shadow: var(--shadow-md);
}
.study-mode-menu.is-viewport-menu {
  position: fixed;
  inset: auto;
  z-index: 320;
  max-height: var(--study-menu-max-height, none);
  overflow-x: hidden;
  overflow-y: auto;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
}
.study-mode-menu[hidden] { display: none; }
.study-mode-menu label {
  display: flex;
  min-height: 42px;
  align-items: center;
  gap: 10px;
  padding: 7px 10px;
  color: var(--ink);
  cursor: pointer;
}
.study-mode-menu label + label { border-top: 1px solid var(--border); }
.study-mode-menu label:hover { background: var(--bg-elev); }
.study-mode-menu input[type="checkbox"] { flex: none; width: 18px; height: 18px; }
/* Both picker menus must escape the compact settings card on iPhone. */
.card-front-mode-block {
  position: relative;
  z-index: 4;
  overflow: visible;
}
.card-front-mode-block .settings-row {
  position: relative;
  z-index: 6;
  overflow: visible;
}
.card-front-mode-block .settings-row + .settings-row { z-index: 5; }
.study-front-menu {
  top: auto;
  bottom: calc(100% + 5px);
}
.settings-block.danger { border-color: var(--bad-soft); }

.button-block { position: relative; overflow: hidden; }
.button-block::before {
  content: "";
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 4px;
  background: var(--border-strong);
}
.button-block.learning-block::before { background: var(--accent); }
.button-block.again-block::before { background: var(--bad); }
.button-block.hard-block::before { background: var(--warn); }
.button-block.good-block::before { background: var(--good); }
.button-block.easy-block::before { background: var(--new); }
.button-block.algo-block::before { background: var(--accent); }
.button-block.leech-block::before { background: var(--warn); }

.button-block .block-header {
  cursor: pointer;
  user-select: none;
  position: relative;
  padding-right: 36px;
  transition: margin-bottom .2s ease, padding-bottom .2s ease, border-color .2s ease;
}
.button-block .block-header .chevron {
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%) rotate(180deg);
  width: 18px;
  height: 18px;
  color: var(--ink-faint);
  transition: transform .2s ease, color .12s;
  pointer-events: none;
}
.button-block .block-header:hover .chevron { color: var(--ink-muted); }
.button-block.collapsed .block-header { margin-bottom: 0; padding-bottom: 0; border-bottom-color: transparent; }
.button-block.collapsed .block-header .chevron { transform: translateY(-50%) rotate(0deg); }
.button-block.collapsed .settings-row,
.button-block.collapsed .example-row,
.button-block.collapsed .algo-options,
.button-block.collapsed .fsrs-extra {
  display: none !important;
}

.block-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin: 0 0 16px;
  padding: 0 0 14px;
  border-bottom: 1px solid var(--border);
}
.block-icon {
  font-size: 28px;
  line-height: 1;
  flex-shrink: 0;
}
.block-heading { flex: 1; min-width: 0; }
.block-heading h3 {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: 17px;
}
.block-heading .block-desc {
  margin: 4px 0 0;
  color: var(--ink-muted);
  font-size: 13.5px;
  line-height: 1.55;
  max-width: 62ch;
}

.button-preview {
  display: inline-flex;
  align-items: center;
  padding: 6px 16px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 13px;
  flex-shrink: 0;
}
.button-preview.grade-again { background: var(--bad-soft); color: var(--bad); }
.button-preview.grade-hard { background: var(--warn-soft); color: var(--warn); }
.button-preview.grade-good { background: var(--good-soft); color: var(--good); }
.button-preview.grade-easy { background: var(--new-soft); color: var(--new); }

.example-row {
  margin-top: 16px;
  padding: 12px 14px;
  background: var(--bg-elev);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  font-size: 13px;
  color: var(--ink-muted);
  display: flex;
  gap: 8px;
  align-items: baseline;
  line-height: 1.55;
}
.example-label {
  font-weight: 600;
  color: var(--ink);
  flex-shrink: 0;
}
.example-text {
  font-family: var(--font-serif);
  font-style: italic;
}

/* Modal */
.modal {
  position: fixed; inset: 0;
  display: grid; place-items: center;
  z-index: 100;
}
.modal[hidden] { display: none; }
.confirm-modal { z-index: 300; }
.duplicate-modal { z-index: 300; }
.duplicate-panel { width: min(520px, 92vw); }
.duplicate-message { margin: 0; line-height: 1.55; }
.duplicate-words { display: inline; }
.duplicate-word {
  appearance: none;
  border: 0;
  border-bottom: 1px dotted currentColor;
  border-radius: 0;
  background: transparent;
  color: var(--accent);
  padding: 0;
  font: inherit;
  font-weight: 650;
  cursor: pointer;
}
.duplicate-word:hover { border-bottom-style: solid; }
.duplicate-word:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 2px; }
.modal-backdrop {
  position: absolute; inset: 0;
  background: rgba(20, 18, 14, 0.45);
  backdrop-filter: blur(4px);
}
.modal-panel {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  width: min(560px, 92vw);
  max-height: 92vh;
  overflow: auto;
  box-shadow: var(--shadow-lg);
  display: flex; flex-direction: column;
}
.modal-panel.small { width: min(440px, 92vw); }
.modal-head {
  display: flex; justify-content: space-between; align-items: center;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
}
.modal-head h2 { margin: 0; font-family: var(--font-serif); font-weight: 500; font-size: 19px; }
.modal-body { padding: 18px 20px; display: flex; flex-direction: column; gap: 14px; }
.modal-foot { padding: 14px 18px; display: flex; justify-content: flex-end; gap: 8px; border-top: 1px solid var(--border); }

.confirm-panel { max-width: 480px; }
.confirm-body { display: grid; gap: 10px; }
.confirm-message,
.confirm-detail { margin: 0; line-height: 1.55; }
.confirm-message { color: var(--ink); font-size: 15px; }
.confirm-detail {
  color: var(--ink-muted);
  font-size: 13.5px;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface-2);
}
.btn.danger {
  background: var(--bad);
  border-color: var(--bad);
  color: #fff;
}
.btn.danger:hover { filter: brightness(.94); }
.btn.danger:focus-visible { outline: 3px solid color-mix(in srgb, var(--bad) 28%, transparent); outline-offset: 2px; }

.form-row { display: grid; gap: 6px; }
.form-row.two { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.form-row label { font-size: 13px; color: var(--ink-muted); font-weight: 500; }
.form-row .hint { color: var(--ink-subtle); font-weight: 400; margin-left: 4px; }
.form-row input, .form-row select, .form-row textarea {
  background: var(--bg-elev);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  outline: none;
  transition: border-color .12s;
  resize: vertical;
}
.form-row input:focus, .form-row select:focus, .form-row textarea:focus { border-color: var(--border-strong); }

input:focus,
input:focus-visible,
select:focus,
select:focus-visible,
textarea:focus,
textarea:focus-visible {
  outline: none;
  box-shadow: none;
}

/* Toast */
.toast {
  position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 14px;
  max-width: calc(100vw - 32px);
  background: var(--ink); color: var(--bg);
  padding: 9px 10px 9px 16px; border-radius: var(--radius);
  font-size: 13.5px;
  box-shadow: var(--shadow-md);
  z-index: 200;
  animation: toastIn .2s ease;
}
.toast-message { min-width: 0; }
.toast-action {
  min-height: 34px;
  padding: 5px 10px;
  border: 1px solid color-mix(in srgb, currentColor 28%, transparent);
  border-radius: 8px;
  background: transparent;
  color: inherit;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}
.toast-action:hover { background: color-mix(in srgb, currentColor 12%, transparent); }
.toast-action:disabled { opacity: .55; cursor: default; }
.toast[hidden] { display: none; }
.toast.is-error { border-color: var(--bad); color: var(--bad); }
.update-notice {
  position: fixed;
  right: 20px;
  bottom: 24px;
  z-index: 101;
  display: flex;
  align-items: center;
  gap: 12px;
  max-width: calc(100vw - 40px);
  padding: 10px 12px 10px 16px;
  border: 1px solid var(--border-strong);
  border-radius: 12px;
  background: var(--panel);
  color: var(--ink);
  box-shadow: var(--shadow-lg);
  font-size: 13px;
}
.update-notice[hidden] { display: none; }
@keyframes toastIn {
  from { opacity: 0; transform: translate(-50%, 8px); }
  to { opacity: 1; transform: translate(-50%, 0); }
}

/* Cloze highlight */
.cloze {
  background: var(--accent-soft);
  color: var(--accent);
  padding: 0 4px;
  border-radius: 4px;
  font-weight: 600;
}
.cloze.hidden {
  background: var(--ink);
  color: var(--ink);
  border-radius: 4px;
  padding: 0 4px;
  user-select: none;
}

.backup-metadata {
  display: grid;
  gap: 4px;
  margin: 10px 0 12px;
  color: var(--ink-subtle);
  font-size: 12px;
  line-height: 1.4;
}

.backup-actions {
  justify-content: flex-end;
  flex-wrap: wrap;
}
.settings-action-list {
  display: grid;
  overflow: hidden;
  margin-top: 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--bg-elev);
}
.settings-action-row {
  display: flex;
  width: 100%;
  min-height: 54px;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 10px 12px;
  color: var(--ink);
  text-align: left;
  cursor: pointer;
}
.settings-action-row + .settings-action-row,
.settings-action-list input + .settings-action-row {
  border-top: 1px solid var(--border);
}
.settings-action-row span:first-child { display: grid; gap: 3px; }
.settings-action-row b { font-size: 13px; font-weight: 650; }
.settings-action-row small { color: var(--ink-subtle); font-size: 12px; }
.settings-action-row > span:last-child { color: var(--ink-subtle); font-size: 22px; }
.settings-action-button {
  border: 0;
  border-radius: 0;
  background: transparent;
  font: inherit;
}
.settings-action-row:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: -2px;
}
.danger-row b { color: var(--bad); }
.recovery-block {
  border-color: color-mix(in srgb, var(--accent) 35%, var(--border));
  background: color-mix(in srgb, var(--accent-soft) 35%, var(--bg-elev));
}
/* P19: Focus trap for settings sheets */
.settings-route-panel[inert] { pointer-events: none; }

/* P20: Back button in sub-panels */
.settings-back-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
}
.settings-back-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 6px 10px;
  border: none;
  border-radius: 8px;
  background: transparent;
  color: var(--accent);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.12s;
}
.settings-back-btn:hover { background: var(--accent-soft); }
.settings-back-btn svg { width: 16px; height: 16px; }
.settings-panel-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 600;
  margin: 0;
}

/* P22: Stepper controls */
.stepper-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}
.stepper-row:last-child { border-bottom: none; }
.stepper-label-wrap {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.stepper-label {
  font-weight: 500;
  font-size: 14.5px;
}
.stepper-hint {
  font-size: 12px;
  color: var(--ink-muted);
}
.stepper-control {
  display: flex;
  align-items: center;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  background: var(--panel);
}
.stepper-btn {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border: none;
  background: transparent;
  color: var(--ink);
  font-size: 18px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.1s;
  touch-action: manipulation;
}
.stepper-btn:hover { background: var(--bg-elev); }
.stepper-btn:active { background: var(--accent-soft); }
.stepper-input {
  width: 52px;
  text-align: center;
  border: none;
  border-left: 1px solid var(--border);
  border-right: 1px solid var(--border);
  background: transparent;
  font-size: 15px;
  font-weight: 600;
  padding: 6px 4px;
  -moz-appearance: textfield;
}
.stepper-input::-webkit-inner-spin-button,
.stepper-input::-webkit-outer-spin-button { -webkit-appearance: none; margin: 0; }

/* P27: FSRS interval preview */
.fsrs-preview {
  margin-top: 12px;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--panel);
}
.fsrs-preview-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 6px;
  margin-top: 8px;
}
.fsrs-preview-grid span {
  display: grid;
  gap: 3px;
  min-width: 0;
  text-align: center;
}
.fsrs-preview-grid b {
  overflow: hidden;
  color: var(--ink-muted);
  font-size: 12px;
  font-weight: 600;
  text-overflow: ellipsis;
}
.fsrs-preview-grid output {
  color: var(--ink);
  font-size: 13px;
  font-variant-numeric: tabular-nums;
  font-weight: 700;
}

/* P33-P36: card mode, current-card timer and theme preview */
.settings-control-stack {
  grid-template-columns: 1fr;
  gap: 8px;
  align-items: stretch;
}
.settings-segmented {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 3px;
  padding: 3px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
}
.settings-segmented button {
  min-height: 34px;
  border: 0;
  border-radius: 7px;
  background: transparent;
  color: var(--ink-muted);
}
.settings-segmented button.active {
  background: var(--panel);
  color: var(--ink);
  box-shadow: var(--shadow-sm);
  font-weight: 600;
}


/* P30: generation mode segmented control */
.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}
.ai-mode-row {
  align-items: start;
}
.ai-mode-segmented {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  width: min(100%, 390px);
  padding: 3px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--bg);
}
.ai-mode-option {
  min-height: 38px;
  padding: 7px 9px;
  border: 0;
  border-radius: 9px;
  background: transparent;
  color: var(--ink-muted);
  font: inherit;
  font-size: 12px;
  font-weight: 650;
  line-height: 1.2;
  cursor: pointer;
}
.ai-mode-option[aria-checked="true"] {
  background: var(--panel);
  color: var(--ink);
  box-shadow: 0 1px 4px rgba(38, 30, 24, 0.12);
}
.ai-mode-option:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

/* P23: Algorithm selector */
.algo-selector {
  display: flex;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  background: var(--panel);
}
.algo-option {
  flex: 1;
  padding: 8px 12px;
  border: none;
  background: transparent;
  font: inherit;
  font-size: 13.5px;
  font-weight: 500;
  color: var(--ink-muted);
  cursor: pointer;
  text-align: center;
  transition: background 0.12s, color 0.12s;
}
.algo-option.active {
  background: var(--accent);
  color: #fff;
}
.algo-option:not(.active):hover { background: var(--bg-elev); }

/* P23: FSRS retention slider */
.retention-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 0;
}
.retention-slider {
  flex: 1;
  height: 4px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--border);
  border-radius: 2px;
  outline: none;
}
.retention-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
}
.retention-value {
  font-weight: 600;
  font-size: 15px;
  min-width: 38px;
  text-align: right;
}
.retention-badge {
  display: inline-flex;
  align-items: center;
  padding: 3px 8px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 600;
  background: var(--accent);
  color: #fff;
}

/* P23: Leech threshold */
.leech-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 0;
}

/* P25: Expert link */
.expert-link-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 0;
  border-top: 1px solid var(--border);
  margin-top: 8px;
}
.expert-link-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: transparent;
  color: var(--ink-muted);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.12s, color 0.12s;
}
.expert-link-btn:hover { background: var(--bg-elev); color: var(--ink); }

/* P25-P26: Expert panel sections */
.expert-section {
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}
.expert-section:last-child { border-bottom: none; margin-bottom: 0; }
.expert-section-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--ink-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin: 0 0 12px;
}

/* P26: SM-2 only visibility */
.sm2-only[hidden] { display: none !important; }