:root {
  --bg: #f7f6f2;
  --surface: #ffffff;
  --surface-soft: #f1efe7;
  --text: #1d1b16;
  --muted: #716c5f;
  --line: #e4dfd1;
  --accent: #16a34a;
  --accent-dark: #116c38;
  --accent-soft: #dcfce7;
  --blue-soft: #e8f2ff;
  --orange-soft: #fff1dc;
  --danger: #b91c1c;
  --danger-soft: #fee2e2;
  --shadow: 0 18px 50px rgba(47, 43, 33, 0.12);
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 10% 0%, rgba(22, 163, 74, 0.12), transparent 34rem),
    linear-gradient(180deg, #fbfaf7 0%, var(--bg) 48%, #efede5 100%);
  line-height: 1.55;
}
a { color: inherit; }
button, input { font: inherit; }
.page-shell { width: min(1160px, calc(100% - 32px)); margin: 0 auto; padding: 28px 0 44px; }
.top-nav { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 34px; }
.brand { text-decoration: none; font-weight: 800; letter-spacing: -0.03em; }
.nav-note { color: var(--muted); font-size: 0.92rem; }
.index-hero, .topic-hero {
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid rgba(228, 223, 209, 0.9);
  box-shadow: var(--shadow);
  border-radius: 30px;
  padding: clamp(26px, 5vw, 54px);
  margin-bottom: 22px;
}
.topic-kicker { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 18px; color: var(--accent-dark); }
.topic-kicker span, .role-row span, .card-topline span, .card-meta span, .card-counts span {
  border: 1px solid var(--line);
  background: rgba(255,255,255,0.72);
  border-radius: 999px;
  padding: 6px 10px;
  font-size: 0.82rem;
  font-weight: 700;
}
h1 { font-size: clamp(2.35rem, 6vw, 5.4rem); line-height: 0.95; letter-spacing: -0.08em; margin: 0 0 18px; }
.index-hero p, .goal { max-width: 820px; color: var(--muted); font-size: 1.08rem; }
.zh-title { color: var(--accent-dark); font-size: 1.24rem; font-weight: 800; margin: -6px 0 12px; }
.role-row { display: flex; flex-wrap: wrap; gap: 9px; align-items: center; margin-top: 18px; }
.topic-title-row { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 18px; align-items: start; }
.topic-title-row h1 { margin-bottom: 18px; }
.topic-progress-box {
  display: grid;
  gap: 8px;
  justify-items: end;
  min-width: 190px;
  padding-top: 6px;
}
.learned-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.86);
  border-radius: 999px;
  padding: 10px 14px;
  font-weight: 900;
  color: var(--text);
  cursor: pointer;
  user-select: none;
}
.learned-toggle input { width: 18px; height: 18px; accent-color: var(--accent); cursor: pointer; }
.learned-toggle:has(input:disabled) { cursor: wait; opacity: .72; }
.learned-toggle:has(input:checked) { background: var(--accent-soft); border-color: rgba(22,163,74,.45); color: var(--accent-dark); }
.progress-status { color: var(--muted); font-size: .84rem; min-height: 1.25em; }
.progress-status.is-ok { color: var(--accent-dark); }
.progress-status.is-error { color: var(--danger); }
.filters { display: grid; grid-template-columns: 1fr minmax(220px, 360px); gap: 14px; align-items: start; margin: 24px 0; }
.filter-panel { display: grid; gap: 8px; }
.filter-label { margin: 0; color: var(--muted); font-size: .78rem; font-weight: 900; letter-spacing: .12em; text-transform: uppercase; }
.status-label { margin-top: 8px; }
.filter-row { display: flex; flex-wrap: wrap; gap: 8px; }
.filter-button, .status-filter-button, .read-button, .line-play, .line-record, .line-listen {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--text);
  border-radius: 999px;
  padding: 10px 14px;
  cursor: pointer;
  transition: transform .16s ease, border-color .16s ease, background .16s ease;
}
.filter-button:hover, .status-filter-button:hover, .read-button:hover, .line-play:hover, .line-record:hover, .line-listen:hover { transform: translateY(-1px); border-color: #bfb7a3; }
.filter-button.active, .status-filter-button.active, .read-button.primary { background: var(--text); color: white; border-color: var(--text); }
.index-progress-status { margin-top: 2px; }
.topic-search { width: 100%; border: 1px solid var(--line); border-radius: 999px; padding: 12px 16px; background: rgba(255,255,255,.86); }
.topic-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.topic-card {
  display: flex;
  flex-direction: column;
  min-height: 280px;
  text-decoration: none;
  background: rgba(255,255,255,.82);
  border: 1px solid var(--line);
  border-radius: 26px;
  padding: 24px;
  box-shadow: 0 10px 35px rgba(47,43,33,.08);
}
.topic-card:hover { border-color: #bcb59f; transform: translateY(-2px); transition: .16s ease; }
.topic-card.is-learned { border-color: rgba(22,163,74,.38); background: linear-gradient(180deg, rgba(220,252,231,.74), rgba(255,255,255,.84)); }
.card-topline, .card-meta, .card-counts { display: flex; flex-wrap: wrap; gap: 8px; }
.card-topline .card-read-badge { color: var(--muted); }
.topic-card.is-learned .card-read-badge { color: var(--accent-dark); background: var(--accent-soft); border-color: rgba(22,163,74,.42); }
.topic-card h2 { margin: 22px 0 8px; font-size: 1.65rem; letter-spacing: -0.04em; line-height: 1.05; }
.topic-zh { color: var(--accent-dark); font-weight: 800; margin: 0; }
.card-goal { color: var(--muted); flex: 1; }
.card-counts { margin-top: 12px; color: var(--muted); }
.player-bar {
  position: sticky;
  top: 12px;
  z-index: 3;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  padding: 12px;
  background: rgba(247, 246, 242, 0.78);
  backdrop-filter: blur(14px);
  border: 1px solid rgba(228,223,209,.82);
  border-radius: 999px;
  margin-bottom: 22px;
}
.content-layout { display: block; }
.dialogue-stack { display: grid; gap: 14px; }
.dialogue-line {
  background: rgba(255,255,255,.86);
  border: 1px solid var(--line);
  border-radius: 24px;
  padding: 18px;
  box-shadow: 0 10px 28px rgba(47,43,33,.07);
}
.dialogue-line.speaker-a { border-left: 6px solid #60a5fa; }
.dialogue-line.speaker-b { border-left: 6px solid #34d399; }
.line-meta { display: flex; justify-content: space-between; color: var(--muted); font-size: .88rem; font-weight: 800; text-transform: uppercase; letter-spacing: .08em; }
.dialogue-line p { font-size: 1.08rem; margin: 10px 0 14px; }
.line-actions { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.line-play, .line-record, .line-listen { padding: 7px 10px; font-size: .86rem; color: var(--muted); }
.line-record { user-select: none; touch-action: none; }
.line-record.is-recording { background: var(--danger); color: #fff; border-color: var(--danger); transform: none; }
.line-listen:disabled { opacity: .45; cursor: not-allowed; transform: none; }
.pronunciation-result { margin-top: 10px; color: var(--muted); font-size: .92rem; min-height: 1.35em; }
.pronunciation-result.is-ok { color: var(--accent-dark); }
.pronunciation-result.is-error { color: var(--danger); }
.pronunciation-result strong { color: var(--text); }
.pronunciation-result .diff-list { display: block; margin-top: 4px; color: var(--muted); }
.learning-word {
  display: inline-block;
  position: relative;
  border-bottom: 2px solid rgba(22,163,74,.45);
  background: linear-gradient(180deg, transparent 56%, var(--accent-soft) 56%);
  border-radius: 4px;
  cursor: pointer;
}
.learning-word:hover, .learning-word:focus, .learning-word.is-active { color: var(--accent-dark); outline: none; background: var(--accent-soft); z-index: 20; }
.inline-word-tip {
  position: absolute;
  left: 50%;
  top: calc(100% + 8px);
  transform: translateX(-50%);
  z-index: 30;
  width: max-content;
  max-width: min(280px, 78vw);
  display: grid;
  gap: 4px;
  padding: 10px 12px;
  color: var(--text);
  background: rgba(255,255,255,.98);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: 0 14px 34px rgba(47,43,33,.18);
  font-size: .92rem;
  line-height: 1.35;
  white-space: normal;
  text-align: left;
}
.inline-word-tip::before {
  content: "";
  position: absolute;
  left: 50%;
  top: -6px;
  width: 10px;
  height: 10px;
  transform: translateX(-50%) rotate(45deg);
  background: rgba(255,255,255,.98);
  border-left: 1px solid var(--line);
  border-top: 1px solid var(--line);
}
.panel-label { margin: 0 0 12px; color: var(--accent-dark); font-weight: 900; text-transform: uppercase; font-size: .78rem; letter-spacing: .12em; }
.tip-ipa { color: var(--muted); font-weight: 700; }
.tip-meaning { color: var(--text); }
.expressions-panel {
  margin-top: 22px;
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 18px;
  background: rgba(255,255,255,.82);
  border: 1px solid var(--line);
  border-radius: 28px;
  padding: 26px;
}
.expressions-panel h2 { margin: 0; letter-spacing: -0.04em; }
.expressions-panel ul { margin: 0; padding: 0; list-style: none; display: grid; gap: 10px; }
.expressions-panel li { border: 1px solid var(--line); background: var(--surface-soft); border-radius: 18px; padding: 14px; }
.expressions-panel strong { display: block; }
.expressions-panel span { display: block; color: var(--muted); margin-top: 4px; }
.topic-pager { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 12px; margin-top: 20px; }
.topic-pager a { text-align: center; text-decoration: none; border: 1px solid var(--line); border-radius: 999px; padding: 12px; background: rgba(255,255,255,.78); }
.site-footer { display: flex; flex-wrap: wrap; justify-content: center; gap: 14px; color: var(--muted); font-size: .86rem; padding: 34px 0 0; }
.site-footer a { color: var(--muted); text-decoration: none; border-bottom: 1px solid currentColor; }
.hidden { display: none !important; }
.is-playing { border-color: rgba(22,163,74,.65); box-shadow: 0 0 0 3px rgba(22,163,74,.10), 0 10px 28px rgba(47,43,33,.07); }
@media (max-width: 860px) {
  .filters, .expressions-panel, .topic-title-row { grid-template-columns: 1fr; }
  .topic-grid { grid-template-columns: 1fr; }
  .topic-progress-box { justify-items: start; min-width: 0; }
  .player-bar { border-radius: 24px; }
}