:root {
  --bg: #f7f9fb;
  --card: #ffffff;
  --ink: #1d2b3a;
  --muted: #6b7a8d;
  --red: #e63946;
  --blue: #457b9d;
  --accent: #2a9d8f;
  --line: #e3e9ef;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
.wrap { max-width: 760px; margin: 0 auto; padding: 20px 16px 60px; }
header.site { text-align: center; padding: 24px 0 8px; }
header.site h1 { margin: 0; font-size: 30px; letter-spacing: 0.5px; }
header.site .tag { color: var(--muted); font-size: 15px; margin-top: 6px; }
.intro { background: var(--card); border: 1px solid var(--line); border-radius: 14px;
  padding: 18px 20px; margin: 18px 0; font-size: 15px; }
.intro h2 { font-size: 17px; margin: 0 0 8px; }
.cards { display: grid; grid-template-columns: 1fr; gap: 14px; margin: 18px 0; }
@media (min-width: 560px) { .cards { grid-template-columns: 1fr 1fr; } }
.game-card { display: block; text-decoration: none; color: inherit;
  background: var(--card); border: 1px solid var(--line); border-radius: 14px;
  padding: 18px; transition: transform .12s ease, box-shadow .12s ease; }
.game-card:hover { transform: translateY(-3px); box-shadow: 0 8px 22px rgba(0,0,0,.08); }
.game-card .emoji { font-size: 30px; }
.game-card h3 { margin: 8px 0 4px; font-size: 18px; }
.game-card p { margin: 0; color: var(--muted); font-size: 14px; }
.btn { display: inline-block; background: var(--red); color: #fff; border: none;
  border-radius: 10px; padding: 11px 18px; font-size: 15px; cursor: pointer;
  text-decoration: none; }
.btn.blue { background: var(--blue); }
.btn.ghost { background: #fff; color: var(--ink); border: 1px solid var(--line); }
.btn:disabled { opacity: .5; cursor: default; }
.ad-slot { margin: 22px 0; padding: 14px; border: 1px dashed #c4cdd6; border-radius: 10px;
  text-align: center; color: var(--muted); font-size: 13px; background: #fbfcfe; }
.back { display: inline-block; margin: 8px 0 18px; color: var(--blue); text-decoration: none; }
h2.page { font-size: 22px; margin: 6px 0 4px; }
.sub { color: var(--muted); margin: 0 0 16px; }
.scorebar { display: flex; justify-content: space-between; align-items: center;
  background: var(--card); border: 1px solid var(--line); border-radius: 10px;
  padding: 10px 14px; margin-bottom: 16px; font-size: 14px; }
/* Match game */
.grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; }
.cell { aspect-ratio: 1 / 1; background: var(--blue); color: #fff; border-radius: 12px;
  display: flex; align-items: center; justify-content: center; cursor: pointer;
  font-size: 20px; text-align: center; padding: 4px; user-select: none;
  transition: background .15s; }
.cell .hanzi { font-size: 34px; }
.cell.flipped { background: #fff; color: var(--ink); border: 2px solid var(--blue); }
.cell.matched { background: var(--accent); color: #fff; cursor: default; }
@media (max-width: 420px) { .cell { font-size: 13px; } .cell .hanzi { font-size: 26px; } }
/* Quiz / MC */
.hanzi-big { font-size: 120px; text-align: center; line-height: 1.2; margin: 10px 0; }
.writer-box { display: flex; justify-content: center; }
.options { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 14px; }
.opt { background: var(--card); border: 1px solid var(--line); border-radius: 10px;
  padding: 12px; cursor: pointer; font-size: 15px; text-align: center; }
.opt.correct { background: var(--accent); color: #fff; border-color: var(--accent); }
.opt.wrong { background: var(--red); color: #fff; border-color: var(--red); }
.center { text-align: center; }
.muted { color: var(--muted); font-size: 14px; }
.tabs { display: flex; gap: 8px; margin-bottom: 16px; }
.tabs .btn { flex: 1; text-align: center; }
.tabs .btn.active { outline: 3px solid rgba(69,123,157,.3); }
/* Idiom chain */
.idiom-cur { background: var(--card); border: 1px solid var(--line); border-radius: 14px;
  padding: 20px; text-align: center; margin-bottom: 14px; }
.idiom-cur .iw { font-size: 60px; letter-spacing: 8px; line-height: 1.1; }
.idiom-cur .ip { color: var(--muted); margin-top: 6px; font-size: 16px; }
.idiom-cur .im { color: var(--ink); margin-top: 2px; font-size: 15px; }
.challenge { text-align: center; font-size: 17px; margin: 14px 0; }
.challenge b { color: var(--red); font-size: 28px; margin-left: 4px; }
.idiom-opt { display: block; width: 100%; background: var(--card); border: 1px solid var(--line);
  border-radius: 12px; padding: 14px; margin-bottom: 10px; cursor: pointer; text-align: center;
  transition: transform .1s ease, box-shadow .1s ease; }
.idiom-opt:hover { transform: translateY(-2px); box-shadow: 0 6px 16px rgba(0,0,0,.07); }
.idiom-opt .iw { font-size: 30px; letter-spacing: 4px; }
.idiom-opt .ip { display: block; color: var(--muted); font-size: 14px; margin-top: 2px; }
.idiom-opt .im { display: block; color: var(--ink); font-size: 13px; margin-top: 2px; }
.idiom-opt.correct { background: var(--accent); color: #fff; border-color: var(--accent); }
.idiom-opt.correct .ip, .idiom-opt.correct .im { color: #eafff8; }
.idiom-opt.wrong { background: var(--red); color: #fff; border-color: var(--red); }
.idiom-opt.wrong .ip, .idiom-opt.wrong .im { color: #ffe9eb; }
.idiom-opt:disabled { cursor: default; transform: none; box-shadow: none; }
.hearts { letter-spacing: 1px; }
.overlay { position: fixed; inset: 0; background: rgba(20,30,45,.62);
  display: flex; align-items: center; justify-content: center; padding: 20px; z-index: 50; }
.overlay .box { background: #fff; border-radius: 16px; padding: 28px 26px; text-align: center;
  max-width: 360px; width: 100%; }
.overlay h3 { margin: 0 0 8px; font-size: 24px; }
.overlay .big { font-size: 44px; font-weight: 700; color: var(--accent); }
@media (max-width: 420px) { .idiom-cur .iw { font-size: 46px; letter-spacing: 5px; } }
/* Footer + consent banner */
.site-foot { margin-top: 30px; padding-top: 18px; border-top: 1px solid var(--line); text-align: center; }
.foot-nav { font-size: 13px; color: var(--muted); line-height: 2.1; }
.foot-nav a { color: var(--blue); text-decoration: none; margin: 0 1px; }
.foot-nav a:hover { text-decoration: underline; }
.consent-bar { position: fixed; left: 0; right: 0; bottom: 0; z-index: 60;
  background: #11202f; color: #eaf2f8; display: flex; flex-wrap: wrap; gap: 10px;
  align-items: center; justify-content: space-between; padding: 12px 16px; font-size: 14px; }
.consent-bar .consent-txt a { color: #7fd1ff; }
.consent-bar .consent-btns { display: flex; gap: 8px; }
/* Character reference grid */
.filter { width: 100%; padding: 12px 14px; font-size: 15px; border: 1px solid var(--line);
  border-radius: 10px; background: var(--card); color: var(--ink); margin: 6px 0; }
.char-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
@media (min-width: 480px) { .char-grid { grid-template-columns: repeat(6, 1fr); } }
@media (min-width: 720px) { .char-grid { grid-template-columns: repeat(8, 1fr); } }
.char-cell { display: block; text-decoration: none; color: inherit; text-align: center;
  background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 8px 4px;
  transition: transform .1s ease, box-shadow .1s ease; }
.char-cell:hover { transform: translateY(-2px); box-shadow: 0 6px 16px rgba(0,0,0,.08); border-color: var(--blue); }
.char-cell .cc-h { font-size: 30px; line-height: 1.1; }
.char-cell .cc-p { font-size: 12px; color: var(--muted); margin-top: 2px; }
.char-cell .cc-m { font-size: 11px; color: var(--blue); line-height: 1.2; margin-top: 1px;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
/* Article tables */
.rad-table { width: 100%; border-collapse: collapse; background: var(--card);
  border: 1px solid var(--line); border-radius: 12px; overflow: hidden; font-size: 14px; }
.rad-table th, .rad-table td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--line); }
.rad-table th { background: #eef3f7; color: var(--ink); font-weight: 600; }
.rad-table tr:last-child td { border-bottom: none; }
.rad-table td:first-child { font-size: 20px; white-space: nowrap; }