:root {
  --bg: #fff9f0;
  --bg-card: #ffffff;
  --text: #2c2416;
  --text-muted: #6b5f4f;
  --accent: #c45c26;
  --accent-soft: #fde8d8;
  --accent-dark: #9a4218;
  --gold: #e8a317;
  --green: #3d8b5e;
  --red: #c0392b;
  --border: #eadfce;
  --shadow: 0 8px 28px rgba(80, 48, 16, 0.08);
  --radius: 16px;
  --font-cn: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-ui: "Onest", system-ui, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-ui);
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(232, 163, 23, 0.12), transparent 28%),
    radial-gradient(circle at top right, rgba(196, 92, 38, 0.1), transparent 24%),
    var(--bg);
  line-height: 1.55;
}

a {
  color: var(--accent-dark);
}

.container {
  width: min(960px, calc(100% - 2rem));
  margin: 0 auto;
}

.site-header {
  padding: 1.25rem 0 0.75rem;
}

.site-header__top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  color: inherit;
}

.brand__mark {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: linear-gradient(135deg, #f0b429, #c45c26);
  display: grid;
  place-items: center;
  font-size: 1.35rem;
}

.brand__text strong {
  display: block;
  font-size: 1.05rem;
}

.brand__text span {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.hero {
  margin: 1rem 0 1.5rem;
  padding: 1.35rem 1.4rem;
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) + 4px);
  background: linear-gradient(135deg, #fff, #fff6ea);
  box-shadow: var(--shadow);
}

.hero__cn {
  font-family: var(--font-cn);
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  font-weight: 700;
  margin: 0 0 0.35rem;
}

.hero__ru {
  margin: 0 0 0.85rem;
  color: var(--text-muted);
}

.hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.3rem 0.65rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-dark);
  font-size: 0.8rem;
  font-weight: 600;
}

.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-bottom: 1rem;
}

.tab {
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text);
  border-radius: 999px;
  padding: 0.55rem 0.9rem;
  font: inherit;
  font-size: 0.88rem;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}

.tab:hover {
  border-color: #d8c5ad;
}

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

.panel {
  display: none;
  margin-bottom: 2rem;
}

.panel.is-active {
  display: block;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.2rem 1.25rem;
}

.card + .card {
  margin-top: 1rem;
}

.card h2 {
  margin: 0 0 0.35rem;
  font-size: 1.15rem;
}

.card__desc {
  margin: 0 0 1rem;
  color: var(--text-muted);
  font-size: 0.92rem;
}

.video-wrap {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  border-radius: 12px;
  overflow: hidden;
  background: #111;
}

.video-wrap iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.story-line {
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--border);
}

.story-line:last-child {
  border-bottom: none;
}

.story-line__cn {
  font-family: var(--font-cn);
  font-size: 1.2rem;
  line-height: 1.7;
  margin-bottom: 0.25rem;
}

.story-line__ruby,
.story-line__ru {
  font-size: 0.92rem;
  color: var(--text-muted);
}

.story-line__ruby {
  margin: 0.2rem 0 0.35rem;
  line-height: 2;
}

.hz-ruby rt {
  color: var(--accent-dark);
  font-size: 0.7em;
  letter-spacing: 0.02em;
}

.story-line__ru {
  margin-top: 0.2rem;
}

.toggle-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 0.85rem;
}

.toggle {
  border: 1px solid var(--border);
  background: #fff;
  border-radius: 999px;
  padding: 0.4rem 0.75rem;
  font: inherit;
  font-size: 0.82rem;
  cursor: pointer;
}

.toggle.is-on {
  background: var(--accent-soft);
  border-color: #e8b48d;
  color: var(--accent-dark);
}

.toggle--quiet {
  background: transparent;
  color: var(--text-muted);
  border-style: dashed;
  font-size: 0.76rem;
  padding: 0.3rem 0.6rem;
}

.flashcard {
  max-width: 420px;
  margin: 0 auto;
  min-height: 220px;
  perspective: 1000px;
  cursor: pointer;
}

.flashcard__inner {
  position: relative;
  width: 100%;
  min-height: 220px;
  transition: transform 0.45s;
  transform-style: preserve-3d;
}

.flashcard.is-flipped .flashcard__inner {
  transform: rotateY(180deg);
}

.flashcard__face {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  padding: 1.25rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: linear-gradient(180deg, #fff, #fff8ef);
  backface-visibility: hidden;
}

.flashcard__face--back {
  transform: rotateY(180deg);
}

.flashcard__hanzi {
  font-family: var(--font-cn);
  font-size: 2.4rem;
  font-weight: 700;
}

.flashcard__pinyin {
  font-size: 1.1rem;
  color: var(--accent-dark);
}

.flashcard__ru {
  font-size: 1rem;
  color: var(--text-muted);
}

.flash-controls,
.quiz-nav,
.build-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  align-items: center;
  justify-content: center;
  margin-top: 1rem;
}

.btn {
  border: none;
  border-radius: 999px;
  padding: 0.65rem 1.1rem;
  font: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.12s, opacity 0.12s;
}

.btn:active {
  transform: scale(0.98);
}

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

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

.btn--ghost {
  background: #fff;
  color: var(--text);
  border: 1px solid var(--border);
}

.progress {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.88rem;
  margin-bottom: 0.75rem;
}

.quiz-options {
  display: grid;
  gap: 0.55rem;
}

.quiz-option {
  text-align: left;
  border: 1px solid var(--border);
  background: #fff;
  border-radius: 12px;
  padding: 0.8rem 0.95rem;
  font: inherit;
  cursor: pointer;
}

.quiz-option:hover {
  border-color: #d8c5ad;
}

.quiz-option.is-correct {
  border-color: var(--green);
  background: #edf8f1;
}

.quiz-option.is-wrong {
  border-color: var(--red);
  background: #fdf0ee;
}

.quiz-option small {
  display: block;
  color: var(--text-muted);
  margin-top: 0.15rem;
}

.feedback {
  margin-top: 0.85rem;
  padding: 0.75rem 0.9rem;
  border-radius: 12px;
  font-size: 0.92rem;
}

.feedback--ok {
  background: #edf8f1;
  color: #245a39;
}

.feedback--bad {
  background: #fdf0ee;
  color: #8b2f24;
}

.match-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 0.65rem;
}

.match-card {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 0.85rem 0.7rem;
  text-align: center;
  background: #fff;
  cursor: pointer;
  min-height: 92px;
}

.match-card.is-selected {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.match-card.is-matched {
  border-color: var(--green);
  background: #edf8f1;
  pointer-events: none;
  opacity: 0.85;
}

.match-card__hanzi {
  font-family: var(--font-cn);
  font-size: 1.8rem;
  font-weight: 700;
}

.match-card__label {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.match-card__py {
  margin-top: 0.35rem;
  font-size: 0.78rem;
  color: var(--accent-dark);
}

.build-area {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  min-height: 58px;
  padding: 0.75rem;
  border: 2px dashed #dccab4;
  border-radius: 12px;
  background: #fffdf8;
  margin-bottom: 0.85rem;
}

.chip {
  border: 1px solid var(--border);
  background: #fff;
  border-radius: 999px;
  padding: 0.45rem 0.8rem;
  font-family: var(--font-cn);
  font-size: 1rem;
  cursor: pointer;
}

.chip.is-used {
  opacity: 0.35;
  pointer-events: none;
}

.chip-pool {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.fill-line {
  font-family: var(--font-cn);
  font-size: 1.15rem;
  line-height: 1.9;
  margin-bottom: 0.85rem;
}

.fill-options {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.pinyin-input {
  width: 100%;
  max-width: 280px;
  padding: 0.7rem 0.85rem;
  border: 1px solid var(--border);
  border-radius: 12px;
  font: inherit;
  font-size: 1rem;
}

.pinyin-prompt {
  font-family: var(--font-cn);
  font-size: 2rem;
  font-weight: 700;
  text-align: center;
  margin: 0.5rem 0 1rem;
}

.pinyin-tone {
  text-align: center;
  color: var(--accent-dark);
  margin-top: -0.45rem;
  margin-bottom: 0.75rem;
  font-size: 0.9rem;
}

.pinyin-word-list {
  margin: 0.85rem 0 0;
  padding-left: 1rem;
  color: var(--text-muted);
}

.pinyin-word-list li {
  margin: 0.2rem 0;
}

.dict-prompt {
  margin-bottom: 0.65rem;
}

.dict-answer {
  font-family: var(--font-cn);
  color: var(--accent-dark);
  margin-bottom: 0.65rem;
}

.speak-hanzi {
  font-family: var(--font-cn);
  font-size: 1.7rem;
  font-weight: 700;
}

.speak-pinyin {
  color: var(--accent-dark);
  margin-top: 0.3rem;
}

.speak-ru {
  color: var(--text-muted);
  margin-top: 0.3rem;
}

.speak-count {
  text-align: center;
  font-weight: 600;
  color: var(--text-muted);
  margin-top: 0.6rem;
}

.scoreboard {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1rem;
}

.scoreboard__item {
  flex: 1 1 140px;
  padding: 0.8rem 0.9rem;
  border-radius: 12px;
  background: #fff8ef;
  border: 1px solid var(--border);
}

.scoreboard__item strong {
  display: block;
  font-size: 1.2rem;
}

.site-footer {
  padding: 1.5rem 0 2rem;
  color: var(--text-muted);
  font-size: 0.85rem;
  text-align: center;
}

@media (max-width: 640px) {
  .container {
    width: min(100% - 1.2rem, 960px);
  }

  .hero,
  .card {
    padding: 1rem;
  }

  .tab {
    font-size: 0.82rem;
    padding: 0.5rem 0.75rem;
  }
}