:root {
  --bg: #f4f5fa;
  --card: #ffffff;
  --ink: #1c2033;
  --sub: #6b7186;
  --line: #e7e9f2;
  --primary: #4f6ef7;
  --primary-soft: #eef1ff;
  --good: #2fa96e;
  --good-soft: #e6f6ee;
  --mid: #e8a13a;
  --mid-soft: #fdf3e2;
  --bad: #e05656;
  --bad-soft: #fdeaea;
  --radius: 18px;
}
* { margin: 0; padding: 0; box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html, body { height: 100%; }
body {
  font-family: -apple-system, "PingFang SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  background: var(--bg); color: var(--ink);
  overscroll-behavior: none;
}
#app { max-width: 480px; margin: 0 auto; min-height: 100%; display: flex; flex-direction: column; }

/* ---------- 顶栏 ---------- */
.topbar {
  display: flex; align-items: center; justify-content: space-between;
  padding: calc(env(safe-area-inset-top) + 14px) 18px 10px;
}
.topbar .title { font-size: 19px; font-weight: 700; letter-spacing: .5px; }
.topbar .streak { font-size: 13px; color: var(--sub); }
.topbar .streak b { color: var(--mid); font-size: 15px; }

/* ---------- 底部导航 ---------- */
.tabbar {
  display: flex; position: sticky; bottom: 0; margin-top: auto;
  background: var(--card); border-top: 1px solid var(--line);
  padding-bottom: env(safe-area-inset-bottom);
}
.tabbar button {
  flex: 1; background: none; border: none; padding: 10px 0 12px;
  font-size: 11px; color: var(--sub); display: flex; flex-direction: column; gap: 3px; align-items: center;
}
.tabbar button .ic { font-size: 21px; line-height: 1; }
.tabbar button.active { color: var(--primary); font-weight: 600; }

/* ---------- 首页 ---------- */
.home { padding: 6px 18px 20px; flex: 1; }
.progress-card {
  background: linear-gradient(135deg, #5a77ff, #4f6ef7 60%, #3d55d8);
  color: #fff; border-radius: var(--radius); padding: 22px 20px;
  display: flex; align-items: center; gap: 18px;
  box-shadow: 0 10px 24px rgba(79,110,247,.28);
}
.ring { position: relative; width: 84px; height: 84px; flex: none; }
.ring svg { transform: rotate(-90deg); }
.ring .num { position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; }
.ring .num b { font-size: 22px; }
.ring .num span { font-size: 10px; opacity: .85; }
.progress-card .info h2 { font-size: 17px; margin-bottom: 6px; }
.progress-card .info p { font-size: 13px; opacity: .9; line-height: 1.6; }

.start-btn {
  margin-top: 18px; width: 100%; border: none; border-radius: 14px;
  background: var(--primary); color: #fff; font-size: 17px; font-weight: 600;
  padding: 15px; box-shadow: 0 8px 18px rgba(79,110,247,.30);
}
.start-btn:active { transform: scale(.98); }
.start-btn:disabled { background: #c4cbde; box-shadow: none; }

.stat-row { display: flex; gap: 12px; margin-top: 16px; }
.stat-box {
  flex: 1; background: var(--card); border-radius: 14px; padding: 14px 12px; text-align: center;
}
.stat-box b { font-size: 20px; display: block; }
.stat-box span { font-size: 11.5px; color: var(--sub); }
.stat-box.p b { color: var(--primary); }
.stat-box.g b { color: var(--good); }
.stat-box.m b { color: var(--mid); }

/* ---------- 学习页 ---------- */
.study { flex: 1; display: flex; flex-direction: column; padding: 4px 18px 16px; }
.study-head { display: flex; justify-content: space-between; font-size: 12.5px; color: var(--sub); margin: 8px 2px 12px; }
.study-head .queue b { color: var(--primary); }

.card-wrap { perspective: 1200px; flex: 1; display: flex; }
.card {
  position: relative; width: 100%; background: var(--card);
  border-radius: 22px; padding: 26px 22px 20px;
  box-shadow: 0 12px 30px rgba(28,32,51,.10);
  display: flex; flex-direction: column;
  transition: transform .3s;
}
.card:active { transform: scale(.995); }
.badge-row { display: flex; gap: 8px; margin-bottom: 14px; }
.badge {
  font-size: 11px; padding: 4px 10px; border-radius: 20px; background: var(--primary-soft); color: var(--primary);
}
.badge.root-badge { background: #e8f5ee; color: #1f8a55; font-weight: 600; }
.word-big { font-size: 40px; font-weight: 700; text-align: center; margin: 8px 0 4px; letter-spacing: .5px; display: flex; align-items: center; justify-content: center; gap: 10px; }
.speak-btn {
  background: var(--primary-soft); border: none; border-radius: 50%;
  width: 42px; height: 42px; font-size: 19px; flex: none; cursor: pointer;
}
.speak-btn:active { transform: scale(.92); }
.ipa-line {
  text-align: center; font-size: 15px; color: var(--sub); min-height: 20px;
  font-family: "Segoe UI", "Charis SIL", sans-serif; margin-bottom: 10px;
}
.root-hint { text-align: center; font-size: 14px; color: var(--primary); margin-bottom: 18px; }
.root-hint b { background: linear-gradient(transparent 62%, #ccd8ff 62%); font-weight: 600; }
.tap-hint { text-align: center; color: #b6bbcc; font-size: 12.5px; margin-top: auto; padding-bottom: 4px; }

.card-back { display: none; }
.card.flipped .card-front { display: none; }
.card.flipped .card-back { display: flex; flex-direction: column; flex: 1; }
.pieces { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; margin-bottom: 16px; }
.piece {
  font-size: 13px; padding: 6px 12px; border-radius: 10px; background: #f5f6fb; border: 1px solid var(--line);
}
.piece b { color: var(--primary); }
.piece.stem { opacity: .75; }
.literal-box {
  text-align: center; font-size: 14.5px; color: var(--sub);
  background: #f8f9fd; border-radius: 12px; padding: 12px 14px; margin-bottom: 14px;
}
.literal-box b { color: var(--ink); font-weight: 600; }
.bridge-text { font-size: 15px; line-height: 1.85; text-align: justify; color: #33384c; margin-bottom: 16px; }
.meaning-box {
  margin-top: auto; text-align: center; font-size: 18px; font-weight: 700; color: var(--good);
  background: var(--good-soft); border-radius: 12px; padding: 12px;
}

.rate-btns { display: flex; gap: 10px; margin-top: 16px; }
.rate-btns button {
  flex: 1; border: none; border-radius: 13px; padding: 14px 0; font-size: 15px; font-weight: 600;
  color: #fff; transition: transform .1s;
}
.rate-btns button:active { transform: scale(.96); }
.rate-btns .r-bad { background: var(--bad); }
.rate-btns .r-mid { background: var(--mid); }
.rate-btns .r-good { background: var(--good); }
.rate-btns .r-small { display: block; font-size: 10.5px; font-weight: 400; opacity: .85; margin-top: 2px; }

.done-box { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 10px; text-align: center; }
.done-box .emoji { font-size: 56px; }
.done-box h2 { font-size: 20px; }
.done-box p { color: var(--sub); font-size: 14px; line-height: 1.7; }

/* ---------- 词库页 ---------- */
.lib { flex: 1; padding: 6px 18px 20px; }
.search-box { margin: 8px 0 14px; }
.search-box input {
  width: 100%; border: 1px solid var(--line); border-radius: 12px; background: var(--card);
  padding: 12px 14px; font-size: 15px; outline: none;
}
.search-box input:focus { border-color: var(--primary); }
.group-item {
  background: var(--card); border-radius: 14px; padding: 14px 16px; margin-bottom: 10px;
  display: flex; align-items: center; gap: 12px; cursor: pointer;
}
.group-item:active { background: #f8f9fd; }
.group-item .g-main { flex: 1; min-width: 0; }
.group-item .g-root { font-weight: 700; font-size: 15.5px; }
.group-item .g-mean { font-size: 12.5px; color: var(--sub); margin-top: 2px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.group-item .g-right { text-align: right; flex: none; }
.group-item .g-count { font-size: 11px; color: var(--sub); }
.mini-bar { width: 56px; height: 5px; background: var(--line); border-radius: 4px; margin-top: 5px; overflow: hidden; }
.mini-bar i { display: block; height: 100%; background: var(--good); border-radius: 4px; }

.group-detail { padding: 6px 18px 20px; flex: 1; }
.back-link { background: none; border: none; color: var(--primary); font-size: 14px; padding: 8px 0; }
.group-head {
  background: linear-gradient(135deg, #5a77ff, #3d55d8); color: #fff; border-radius: var(--radius);
  padding: 20px; margin-bottom: 14px;
}
.group-head .root-name { font-size: 22px; font-weight: 700; }
.group-head .root-mean { font-size: 14px; opacity: .92; margin-top: 6px; }
.group-head .root-cnt { font-size: 12px; opacity: .8; margin-top: 8px; }
.word-row {
  background: var(--card); border-radius: 13px; padding: 13px 15px; margin-bottom: 9px;
  display: flex; justify-content: space-between; align-items: center; gap: 10px;
}
.word-row .w-main { flex: 1; min-width: 0; }
.word-row .w-word { font-weight: 600; font-size: 15.5px; }
.word-row .w-mean { font-size: 12.5px; color: var(--sub); margin-top: 2px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.word-row .w-state { flex: none; font-size: 11px; padding: 3px 9px; border-radius: 12px; }
.w-state.new { background: #eef0f6; color: #9aa0b5; }
.w-state.learning { background: var(--mid-soft); color: #c98a1e; }
.w-state.mastered { background: var(--good-soft); color: var(--good); }

/* ---------- 搜索结果 ---------- */
.search-hit { font-size: 13px; color: var(--sub); margin: 10px 2px; }
.search-hit b { color: var(--primary); }

@media (min-width: 500px) { #app { border-left: 1px solid var(--line); border-right: 1px solid var(--line); } }