:root {
  --bg: #f3efe7;
  --bg-deep: #e7e1d6;
  --card: #fffdf8;
  --ink: #1f1a17;
  --muted: #5c534c;
  --line: #e3d9cc;
  --accent: #0f6e67;
  --accent-soft: #d7ebe7;
  --accent-ink: #0c4f4a;
  --shadow: 0 12px 30px rgba(70, 48, 24, 0.08);
  --danger: #7d2e2e;
  --again: #7d2e2e;
  --hard: #8a4e16;
  --good: #0e5f59;
  --easy: #1b4f38;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1c1917;
    --bg-deep: #141211;
    --card: #292421;
    --ink: #f6f1ea;
    --muted: #c4b8ae;
    --line: #3d352f;
    --accent: #3dbeb4;
    --accent-soft: #163632;
    --accent-ink: #d5f7f3;
    --shadow: 0 12px 30px rgba(0, 0, 0, 0.28);
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

[hidden] { display: none !important; }

html, body {
  margin: 0;
  height: 100%;
}

body {
  min-height: 100dvh;
  background: #ddd6cc;
  color: var(--ink);
  font-family: "PingFang TC", "Noto Sans TC", "Heiti TC", "Microsoft JhengHei", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 17px;
  line-height: 1.45;
}

@media (prefers-color-scheme: dark) {
  body { background: #100e0c; }
}

button, input, textarea { font: inherit; color: inherit; }

button { cursor: pointer; }

button, .flashcard { touch-action: manipulation; -webkit-tap-highlight-color: transparent; }

.app {
  max-width: 520px;
  margin: 0 auto;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  box-shadow: 0 0 0 1px rgba(40, 24, 8, 0.06);
}

@media (max-width: 560px) {
  body { background: var(--bg); }
  .app { box-shadow: none; }
}

.skip {
  position: absolute;
  left: 12px;
  top: 12px;
  transform: translateY(-140%);
  background: var(--ink);
  color: var(--bg);
  padding: 8px 12px;
  border-radius: 10px;
  z-index: 40;
}

.skip:focus { transform: none; }

.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: calc(12px + env(safe-area-inset-top)) 16px 10px;
}

.brand {
  margin: 0;
  font-size: 1.35rem;
  font-weight: 760;
  letter-spacing: 0.01em;
}

.tag, .hint, .lede, .session-count, .stat-line, .kicker, .prompt {
  margin: 0;
  color: var(--muted);
}

.tag { font-size: 0.92rem; }

.due-pill {
  border: 0;
  background: var(--accent);
  color: #fff;
  border-radius: 999px;
  min-height: 44px;
  padding: 0 14px;
  font-weight: 760;
  white-space: nowrap;
}

.banner {
  margin: 0 16px 8px;
  padding: 12px;
  border-radius: 14px;
  background: var(--accent-soft);
  color: var(--accent-ink);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.banner p { margin: 0; }

main {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  padding: 4px 16px 12px;
}

.view { display: none; }

.view:not([hidden]) {
  display: flex;
  flex-direction: column;
  gap: 12px;
  min-height: 0;
  flex: 1;
  overflow: auto;
}

.scroll:not([hidden]) { overflow: auto; }

h2 { margin: 0; font-size: 1.25rem; }

#view-review:not([hidden]) {
  overflow: hidden;
  gap: 6px;
}

#review-card-wrap { overflow: hidden; gap: 8px; }

#view-review .flashcard {
  min-height: 0;
  overflow: hidden;
  justify-content: flex-start;
  padding: 14px 14px 10px;
  gap: 8px;
}

#view-review .flashcard.revealed {
  padding: 10px 12px 8px;
  gap: 6px;
}

#review-empty {
  min-height: 0;
  overflow: auto;
}

#open-commute { flex: none; min-height: 44px; padding: 8px 14px; }

#view-commute:not([hidden]) {
  overflow: hidden;
  gap: 10px;
}

.commute-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
  flex: none;
}

.commute-body {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.commute-card {
  flex: 1 1 auto;
  min-height: 0;
  overflow: auto;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  justify-content: safe center;
  gap: 10px;
  text-align: center;
  padding: 8px 4px;
}

.commute-card .word,
.commute-card .meaning,
.commute-card .example-line,
.commute-card .example-zh { margin: 0; }

.commute-card.reverse #commute-zh { order: 1; }
.commute-card.reverse #commute-en { order: 2; }
.commute-card.reverse #commute-breakdown { order: 3; }
.commute-card.reverse #commute-example-zh { order: 4; }
.commute-card.reverse #commute-example { order: 5; }

.commute-card .is-speaking { color: var(--accent-ink); }

.commute-controls {
  flex: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.commute-controls .btn { width: 100%; }

#commute-play { min-height: 72px; font-size: 1.35rem; }

#commute-prev,
#commute-next,
#commute-end { min-height: 56px; font-size: 1.1rem; }

@media (orientation: landscape), (max-height: 480px) {
  #view-commute:not([hidden]) {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(168px, 220px);
    grid-template-rows: auto minmax(0, 1fr);
    gap: 8px 12px;
    overflow: hidden;
  }

  .commute-head { grid-column: 1 / -1; }

  .commute-body {
    grid-column: 1;
    grid-row: 2;
    min-height: 0;
    overflow: hidden;
  }

  .commute-controls {
    grid-column: 2;
    grid-row: 2;
    align-self: end;
    min-height: 0;
  }

  .commute-card {
    justify-content: flex-start;
    text-align: left;
    padding: 0 2px 4px;
  }

  .commute-card .word { font-size: 1.65rem; line-height: 1.25; }

  .commute-card .meaning { font-size: 1.2rem; line-height: 1.35; }

  .commute-card .example-line,
  .commute-card .example-zh { font-size: 1rem; }

  #commute-play { min-height: 48px; font-size: 1.05rem; }

  #commute-prev,
  #commute-next,
  #commute-end { min-height: 44px; font-size: 1rem; }
}

.review-settings {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  flex: none;
}

.segment {
  display: flex;
  flex: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  overflow: hidden;
  background: var(--card);
}

.segment button {
  min-height: 40px;
  padding: 6px 12px;
  border: 0;
  background: transparent;
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 760;
}

.segment button[aria-pressed="true"] {
  background: var(--accent-soft);
  color: var(--accent-ink);
}

.card-wrap {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.flashcard {
  flex: 1;
  min-height: 180px;
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: var(--card);
  box-shadow: var(--shadow);
  padding: 22px 18px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  text-align: center;
}

.card-body {
  flex: 1 1 auto;
  min-height: 0;
  width: 100%;
  overflow: auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  justify-content: safe center;
  gap: 8px;
}

#view-review .flashcard.revealed .card-body,
#view-review .flashcard.revealed .card-face,
#view-review .flashcard.revealed .example-block { gap: 4px; }

.card-face {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.card-face:active { transform: scale(0.99); }

.speak {
  min-height: 44px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-ink);
  font-weight: 760;
  padding: 8px 16px;
}

.example-block {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.speak-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.example-block .speak-row,
#review-speak { justify-content: center; }

#review-speak {
  flex: none;
  width: 100%;
  flex-wrap: nowrap;
  gap: 6px;
}

#review-speak .speak {
  flex: 1 1 0;
  max-width: 7.5rem;
  min-height: 40px;
  padding: 6px 10px;
  font-size: 0.95rem;
}

.example-line {
  margin: 0;
  font-size: 1.05rem;
  line-height: 1.4;
  overflow-wrap: anywhere;
}

mark.term {
  background: #f4d48a;
  color: #1f1a17;
  font-weight: 760;
  padding: 0 0.08em;
  border-radius: 0.18em;
}

@media (prefers-color-scheme: dark) {
  mark.term {
    background: #8a6a22;
    color: #fff8e8;
  }
}

.example-zh {
  margin: 0;
  color: var(--muted);
  overflow-wrap: anywhere;
}

.breakdown {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.4;
  overflow-wrap: anywhere;
}

.flashcard .breakdown,
.card-row .breakdown { width: 100%; }

.breakdown .kicker { display: block; margin-bottom: 2px; }

.commute-card .breakdown { font-size: 0.92rem; }

.title-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.title-row h3 { flex: 1; margin: 0; }

.kicker {
  font-size: 0.85rem;
  letter-spacing: 0.08em;
}

.word {
  font-family: "Iowan Old Style", Palatino, "Palatino Linotype", "Songti TC", Georgia, serif;
  font-size: clamp(2rem, 8vw, 2.7rem);
  font-weight: 680;
  line-height: 1.2;
  overflow-wrap: anywhere;
}

.flashcard.revealed .word {
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  color: var(--muted);
}

#view-review .flashcard.revealed .meaning {
  font-size: clamp(1.22rem, 5.2vw, 1.6rem);
  line-height: 1.28;
}

#view-review .flashcard.revealed .kicker {
  font-size: 0.75rem;
  letter-spacing: 0.04em;
}

#view-review .flashcard.revealed .example-line,
#view-review .flashcard.revealed .example-zh,
#view-review .flashcard.revealed .breakdown {
  font-size: 0.92rem;
  line-height: 1.3;
}

.meaning {
  font-size: clamp(1.55rem, 6.5vw, 2.15rem);
  font-weight: 720;
  line-height: 1.35;
  overflow-wrap: anywhere;
}

.meaning[lang="en"] {
  font-family: "Iowan Old Style", Palatino, "Palatino Linotype", Georgia, serif;
}

.prompt { font-size: 0.95rem; }

.ratings {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  flex: none;
}

.rate {
  min-height: 64px;
  border: 0;
  border-radius: 16px;
  color: #fff;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  padding: 8px;
}

.rate:active { filter: brightness(0.92); }

.rate-label { font-size: 1.2rem; font-weight: 760; }

.rate-delay { font-size: 0.92rem; opacity: 0.92; }

.rate-again { background: var(--again); }
.rate-hard { background: var(--hard); }
.rate-good { background: var(--good); }
.rate-easy { background: var(--easy); }

.empty {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 12px;
  text-align: center;
  padding: 12px 8px 24px;
}

.empty h2 { font-size: 1.45rem; }

label {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-weight: 700;
}

input, textarea {
  width: 100%;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 12px 14px;
  font-size: 17px;
  font-weight: 500;
}

textarea { resize: vertical; min-height: 120px; }

input:focus-visible, textarea:focus-visible, button:focus-visible, .flashcard:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
}

.btn {
  min-height: 52px;
  border: 0;
  border-radius: 14px;
  padding: 12px 16px;
  background: var(--accent);
  color: #fff;
  font-weight: 760;
  font-size: 1.05rem;
}

@media (prefers-color-scheme: dark) {
  .btn,
  .due-pill { color: #08332f; }
}

.btn.secondary {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line);
}

.btn.danger, .dialog-card .btn.danger {
  background: var(--danger);
  color: #fff;
  border: 0;
}

.btn:disabled { opacity: 0.55; }

.stack, form { display: flex; flex-direction: column; gap: 10px; }

.row { display: flex; gap: 8px; }

.row > * { flex: 1; }

fieldset {
  border: 1px solid var(--line);
  border-radius: 14px;
  margin: 0;
  padding: 8px 12px 12px;
}

legend { padding: 0 6px; font-weight: 760; }

.choice {
  flex-direction: row;
  align-items: center;
  min-height: 48px;
  font-weight: 650;
}

.choice input {
  width: 1.3rem;
  height: 1.3rem;
  accent-color: var(--accent);
}

.list-head { display: flex; justify-content: space-between; align-items: baseline; gap: 8px; }

.card-list, .deck-list { display: flex; flex-direction: column; gap: 10px; padding-bottom: 8px; }

.chips {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  flex: none;
  padding-bottom: 2px;
}

.chip {
  flex: none;
  min-height: 40px;
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--card);
  font-size: 0.95rem;
  font-weight: 760;
}

.chip[aria-pressed="true"] {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--accent-ink);
}

.deck-tools { display: flex; gap: 8px; flex: none; }

.deck-tools .btn {
  min-height: 44px;
  padding: 8px 12px;
  font-size: 0.95rem;
}

.deck-row {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 14px;
  display: flex;
  flex-direction: row;
  align-items: flex-start;
  gap: 12px;
  font-weight: 500;
  cursor: pointer;
}

.deck-row input {
  width: 1.45rem;
  height: 1.45rem;
  margin-top: 0.15rem;
  flex: none;
  accent-color: var(--accent);
}

.deck-copy {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.deck-row h3 { margin: 0; font-size: 1.15rem; font-weight: 760; }

.deck-row .hint { margin: 0; }

.deck-row:has(input:checked) {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.deck-actions {
  flex: none;
  z-index: 2;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 8px 0 0;
  background: var(--bg);
}

.deck-actions .btn { width: 100%; }

.card-row {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.card-row h3 {
  margin: 0;
  font-size: 1.2rem;
  overflow-wrap: anywhere;
}

.card-row .meaning-line {
  margin: 4px 0 0;
  overflow-wrap: anywhere;
}

.card-row .meta { margin: 6px 0 0; color: var(--muted); font-size: 0.92rem; }

.card-row .meta.due { color: var(--accent-ink); font-weight: 700; }

.danger-zone {
  margin-top: 8px;
  padding-top: 8px;
  border-top: 1px solid var(--line);
}

.nav {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 4px;
  padding: 6px 8px calc(8px + env(safe-area-inset-bottom));
  border-top: 1px solid var(--line);
  background: color-mix(in srgb, var(--bg) 92%, var(--card));
}

.nav-btn {
  position: relative;
  min-height: 52px;
  padding: 4px 2px;
  border: 0;
  border-radius: 12px;
  background: transparent;
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 760;
}

#view-decks:not([hidden]) { overflow: hidden; }

#view-decks .deck-list {
  flex: 1;
  min-height: 0;
  overflow: auto;
}

.nav-btn.active {
  background: var(--accent-soft);
  color: var(--accent-ink);
}

.badge {
  position: absolute;
  top: 4px;
  right: 8px;
  min-width: 1.25rem;
  height: 1.25rem;
  padding: 0 4px;
  border-radius: 999px;
  background: var(--danger);
  color: #fff;
  font-size: 0.72rem;
  line-height: 1.25rem;
  text-align: center;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: calc(84px + env(safe-area-inset-bottom));
  transform: translateX(-50%);
  max-width: min(440px, calc(100% - 32px));
  background: #1f1a17;
  color: #fffdf8;
  padding: 12px 16px;
  border-radius: 999px;
  z-index: 30;
  text-align: center;
}

.dialog-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(28, 24, 20, 0.48);
  display: grid;
  align-items: end;
  justify-items: center;
  padding: 16px;
  padding-bottom: calc(16px + env(safe-area-inset-bottom));
  z-index: 25;
}

.dialog-card {
  width: min(520px, 100%);
  background: var(--card);
  color: var(--ink);
  border-radius: 20px;
  padding: 20px 16px 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.dialog-card p { margin: 0; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition: none !important;
    animation: none !important;
  }
}