:root {
  --bg: #fdf6ee;
  --card-bg: #ffffff;
  --ink: #2a1e17;
  --ink-dim: #7a6a5c;
  --accent: #b3272d;
  --accent-dark: #8f1f24;
  --gold: #c9a24b;
  --border: #e8dcc8;
  --correct: #2e7d32;
  --correct-bg: #e8f5e9;
  --wrong: #c62828;
  --wrong-bg: #fdecea;
  --radius: 14px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1b1512;
    --card-bg: #241b16;
    --ink: #f2e9dd;
    --ink-dim: #b4a493;
    --accent: #e05a52;
    --accent-dark: #c94a44;
    --gold: #d9b968;
    --border: #3a2d24;
    --correct: #7bd389;
    --correct-bg: #1c3320;
    --wrong: #ff8a80;
    --wrong-bg: #3a1f1d;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  display: flex;
  justify-content: center;
  padding: 32px 16px 48px;
}

.app {
  width: 100%;
  max-width: 1100px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 18px;
}

/* Everything except the play-area (card + sidebar) stays narrow and
   centered, matching the original single-column layout. */
.app-header,
.range-select,
.mistakes-bar,
.stats-bar,
.hint {
  width: 100%;
  max-width: 480px;
}

.app-header {
  text-align: center;
}

.app-header h1 {
  margin: 0 0 4px;
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--accent-dark);
}

.app-header .dim {
  color: var(--gold);
}

.subtitle {
  margin: 0;
  color: var(--ink-dim);
  font-size: 0.9rem;
}

.range-select {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
}

.range-btn {
  border: 1px solid var(--border);
  background: var(--card-bg);
  color: var(--ink);
  padding: 8px 16px;
  border-radius: 999px;
  font-size: 0.9rem;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.range-btn:hover {
  border-color: var(--accent);
}

.range-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.mistakes-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 6px;
  font-size: 0.8rem;
  color: var(--ink-dim);
}

.btn-link {
  background: none;
  border: none;
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  padding: 2px 4px;
}

.btn-link:hover:not(:disabled) {
  text-decoration: underline;
}

.btn-link:disabled {
  color: var(--ink-dim);
  cursor: default;
  opacity: 0.6;
}

.stats-bar {
  display: flex;
  justify-content: space-around;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 8px;
}

.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
}

.stat-value {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--accent-dark);
}

.stat-label {
  font-size: 0.72rem;
  color: var(--ink-dim);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.play-area {
  width: 100%;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  gap: 20px;
}

.card {
  flex: 1 1 320px;
  min-width: 0;
  max-width: 480px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.04);
}

/* Wide screens: the card sits dead centre, with Quick Reference in the
   right-hand gutter, so the card doesn't shift when the panel appears. */
@media (min-width: 1100px) {
  .play-area {
    display: grid;
    grid-template-columns: 1fr 480px 1fr;
  }

  .card {
    grid-column: 2;
  }

  .lookup-panel {
    grid-column: 3;
    justify-self: start;
  }
}

@media (max-width: 760px) {
  .play-area {
    flex-direction: column;
    align-items: stretch;
  }

  .card {
    max-width: none;
  }

  .lookup-panel {
    width: 100%;
    flex: 1 1 auto;
  }
}

.hanzi {
  font-family: "PingFang TC", "Microsoft JhengHei", "Heiti TC", "Noto Sans TC", "Noto Sans CJK TC", sans-serif;
  font-size: clamp(3rem, 14vw, 4.5rem);
  font-weight: 700;
  color: var(--ink);
  letter-spacing: 0.05em;
  min-height: 1.2em;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
}

.answer-form {
  width: 100%;
  display: flex;
  gap: 8px;
}

.pinyin-input {
  flex: 1;
  min-width: 0;
  padding: 14px;
  font-family: "Noto Sans", Calibri, Arial, sans-serif;
  font-size: 3rem;
  font-weight: 400;
  line-height: 1.4;
  letter-spacing: 0.01em;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  background: var(--bg);
  color: var(--ink);
  outline: none;
  transition: border-color 0.15s;
}

.pinyin-input:focus {
  border-color: var(--accent);
}

.btn {
  border: none;
  border-radius: 10px;
  padding: 12px 18px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s, opacity 0.15s;
  white-space: nowrap;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-dark);
}

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

.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.feedback {
  min-height: 1.6em;
  width: 100%;
  text-align: center;
  font-size: 1.05rem;
  border-radius: 10px;
  padding: 0;
  transition: padding 0.15s;
}

.feedback.correct,
.feedback.wrong {
  padding: 10px 12px;
}

.feedback.correct {
  background: var(--correct-bg);
  color: var(--correct);
  font-weight: 500;
}

.feedback.wrong {
  background: var(--wrong-bg);
  color: var(--wrong);
  font-weight: 500;
}

.feedback .answer-pinyin {
  font-family: "Noto Sans", Calibri, Arial, sans-serif;
  font-weight: 600;
  font-size: 2.1em;
  line-height: 1.7;
  display: inline-block;
}

.practice-note {
  margin-top: 6px;
  font-size: 0.82rem;
  font-weight: 600;
}

.practice-note.correct {
  color: var(--correct);
}

.practice-note.wrong {
  color: var(--wrong);
}

.use-cases {
  margin-top: 10px;
  padding-top: 8px;
  border-top: 1px solid var(--border);
  text-align: left;
  font-family: "Noto Sans", Calibri, Arial, sans-serif;
  font-size: 0.88rem;
  font-weight: 400;
  color: var(--ink-dim);
  line-height: 1.6;
}

.lookalike-note {
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 6px;
}

.use-cases-title {
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  font-size: 0.7rem;
  margin-bottom: 2px;
}

/* ---- Word Order ---- */

.sentence-builder {
  display: none;
  width: 100%;
  flex-direction: column;
  gap: 18px;
}

.card.sentence-mode .sentence-builder {
  display: flex;
}

.card.sentence-mode .hanzi,
.card.sentence-mode .pinyin-input {
  display: none;
}

.card.sentence-mode .answer-form .btn {
  flex: 1;
}

.level-select {
  display: flex;
  gap: 6px;
  justify-content: center;
}

.level-btn {
  border: 1px solid var(--border);
  background: transparent;
  color: var(--ink-dim);
  padding: 4px 14px;
  border-radius: 999px;
  font-size: 0.8rem;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}

.level-btn:hover {
  border-color: var(--accent);
}

.level-btn.active {
  border-color: var(--accent);
  color: var(--accent);
  font-weight: 600;
}

/* The line the sentence is written on. */
.sentence-answer {
  min-height: 64px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 8px 2px;
  border-bottom: 2px dashed var(--border);
}

.sentence-answer:empty::before {
  content: "Tap the words in order";
  color: var(--ink-dim);
  font-size: 0.9rem;
}

.sentence-bank {
  min-height: 56px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

.chunk {
  font-family: "PingFang TC", "Microsoft JhengHei", "Heiti TC", "Noto Sans TC", "Noto Sans CJK TC", sans-serif;
  font-size: 1.45rem;
  padding: 8px 14px;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  background: var(--bg);
  color: var(--ink);
  cursor: pointer;
  box-shadow: 0 2px 0 var(--border);
  transition: border-color 0.15s, transform 0.05s;
  -webkit-tap-highlight-color: transparent;
}

.chunk:hover {
  border-color: var(--accent);
}

.chunk:active {
  transform: translateY(1px);
  box-shadow: none;
}

.sentence-answer .chunk {
  background: var(--card-bg);
  border-color: var(--accent);
}

.sentence-reveal {
  margin-top: 8px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.sentence-hanzi {
  font-family: "PingFang TC", "Microsoft JhengHei", "Heiti TC", "Noto Sans TC", "Noto Sans CJK TC", sans-serif;
  font-size: 1.6em;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.sentence-pinyin {
  font-family: "Noto Sans", Calibri, Arial, sans-serif;
  font-size: 1.15em;
}

.sentence-gloss {
  font-size: 0.85em;
  font-weight: 400;
  opacity: 0.85;
}

.actions {
  width: 100%;
  display: flex;
  justify-content: space-between;
  gap: 8px;
}

.hidden {
  display: none !important;
}

.hint {
  text-align: center;
  color: var(--ink-dim);
  font-size: 0.78rem;
  line-height: 1.6;
}

.hint p {
  margin: 0 0 7px;
}

.hint .modes {
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px solid var(--border);
}

.hint .modes strong {
  color: var(--ink);
}

.hint code {
  font-family: "Noto Sans", Calibri, Arial, sans-serif;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 1px 6px;
  font-size: 0.9rem;
}

.lookup-panel {
  width: 260px;
  flex: 0 0 260px;
  align-self: stretch;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.lookup-title {
  margin: 0;
  font-size: 1rem;
  font-weight: 700;
  color: var(--accent-dark);
}

.lookup-sub {
  margin: 0;
  font-size: 0.8rem;
  color: var(--ink-dim);
}

.lookup-form {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.lookup-input {
  flex: 1;
  min-width: 0;
  padding: 10px 12px;
  font-family: "Noto Sans", Calibri, Arial, sans-serif;
  font-size: 1.1rem;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  background: var(--bg);
  color: var(--ink);
  outline: none;
  transition: border-color 0.15s;
}

.lookup-input:focus {
  border-color: var(--accent);
}

.lookup-result {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.lookup-row {
  font-family: "Noto Sans", Calibri, Arial, sans-serif;
  font-size: 0.95rem;
  padding: 8px 10px;
  border-radius: 8px;
}

.lookup-row.learned {
  background: var(--correct-bg);
  color: var(--correct);
}

.lookup-row.unlearned,
.lookup-row.invalid {
  background: var(--wrong-bg);
  color: var(--wrong);
}

.lookup-chars {
  font-family: "PingFang TC", "Microsoft JhengHei", "Heiti TC", "Noto Sans TC", "Noto Sans CJK TC", sans-serif;
  font-weight: 700;
  font-size: 1.2em;
}

/* Phone sizing. Must stay last: the base .pinyin-input rule sits further up
   the file, so an earlier media query would lose on source order.
   A 3rem box only fits a few characters at 375px, hiding what's being typed. */
@media (max-width: 480px) {
  /* Stack the button under the input so the answer gets the full card width. */
  .answer-form {
    flex-direction: column;
  }

  .pinyin-input {
    font-size: 1.9rem;
    padding: 12px;
  }

  .hint {
    font-size: 0.72rem;
  }
}