/* ===== 四下数学21天复习 · 共享样式 ===== */
:root{
  --bg:#fef6ff;
  --ink:#3a2e4d;
  --ink-soft:#6b5e80;
  --card:#ffffff;
  --line:#ecdcf5;
  --purple:#8b5cf6;
  --purple-d:#6d3bd6;
  --pink:#ff7eb6;
  --yellow:#ffd166;
  --green:#3ec98a;
  --green-d:#1f9d68;
  --red:#ff6b6b;
  --blue:#5aa9ff;
  --shadow:0 8px 22px rgba(123,76,200,.16);
  --radius:18px;
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;padding:0}
body{
  font-family:-apple-system,"PingFang SC","Microsoft YaHei",sans-serif;
  background:
    radial-gradient(circle at 12% 8%,#fff0fb 0,transparent 40%),
    radial-gradient(circle at 88% 0%,#eef3ff 0,transparent 38%),
    var(--bg);
  color:var(--ink);
  line-height:1.7;
  font-size:17px;
  padding-bottom:40px;
  -webkit-text-size-adjust:100%;
}
.wrap{max-width:680px;margin:0 auto;padding:0 16px}

/* 顶栏 */
.topbar{
  position:sticky;top:0;z-index:20;
  background:rgba(255,255,255,.86);backdrop-filter:blur(8px);
  border-bottom:1px solid var(--line);
}
.topbar .row{max-width:680px;margin:0 auto;padding:10px 16px;display:flex;align-items:center;gap:10px}
.back{
  display:inline-flex;align-items:center;gap:6px;
  background:var(--purple);color:#fff;border:none;border-radius:999px;
  padding:9px 16px;font-size:16px;font-weight:700;cursor:pointer;text-decoration:none;
}
.back:active{transform:scale(.96)}
.topbar .ttl{font-weight:800;font-size:17px;flex:1;text-align:center}
.stars-mini{font-size:18px;min-width:64px;text-align:right;letter-spacing:1px}

/* 通用卡片 */
.card{
  background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);
  padding:20px;margin:18px 0;border:1px solid var(--line);
}
.goal{
  background:linear-gradient(135deg,#fff4c2,#ffe08a);
  border:none;color:#7a5a00;
}
.goal h2{margin:0 0 6px;font-size:18px}
.goal p{margin:0;font-weight:600}

h1.day-h{font-size:26px;text-align:center;margin:22px 0 4px}
.day-sub{text-align:center;color:var(--ink-soft);margin:0 0 6px;font-weight:600}

/* 故事/开场 */
.scene{
  background:linear-gradient(135deg,#f3ecff,#ffe9f6);
  border:2px dashed var(--purple);border-radius:var(--radius);
  padding:18px;margin:18px 0;font-size:17px;
}
.scene .emoji{font-size:40px;display:block;text-align:center;margin-bottom:6px}

/* 知识点讲解 */
.lesson h3{font-size:20px;margin:4px 0 10px;display:flex;align-items:center;gap:8px}
.lesson p{margin:8px 0}
.hl{background:linear-gradient(transparent 55%,#ffe08a 55%);font-weight:800;padding:0 2px}
.hl-p{color:var(--purple-d);font-weight:800}
.hl-g{color:var(--green-d);font-weight:800}
.hl-r{color:#d63d3d;font-weight:800}
.tip{
  background:#eef9ff;border-left:5px solid var(--blue);
  border-radius:10px;padding:12px 14px;margin:12px 0;font-size:16px;
}
.tip b{color:#1f6fc4}
.warn{background:#fff0f0;border-left-color:var(--red)}
.warn b{color:#d63d3d}

/* 例子盒子 / 算式 */
.eg{
  background:#f7f3ff;border-radius:14px;padding:14px 16px;margin:12px 0;
  font-size:19px;text-align:center;
}
.calc{font-size:22px;font-weight:800;letter-spacing:1px;text-align:center;margin:8px 0}
.calc .op{color:var(--pink)}
.step{color:var(--ink-soft);font-size:16px;text-align:center;margin:4px 0}

/* 图示 SVG */
.fig{margin:14px 0}
.fig svg{display:block;width:100%;height:auto;max-width:340px;margin:0 auto;
  background:#fcf8ff;border:1px solid var(--line);border-radius:14px}
.fig .cap{font-size:13.5px;color:var(--ink-soft);text-align:center;margin-top:6px;font-weight:600}
.fig-row{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;margin:14px 0}
.fig-row figure{flex:1 1 90px;max-width:120px;margin:0}
.fig-row svg{display:block;width:100%;height:auto;background:#fcf8ff;border:1px solid var(--line);border-radius:12px}
.fig-row figcaption{font-size:12.5px;line-height:1.35;color:var(--ink);text-align:center;margin-top:5px;font-weight:700}

/* 小贴纸/数字块 */
.chips{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;margin:12px 0}
.chip{
  background:var(--purple);color:#fff;border-radius:12px;padding:8px 14px;
  font-weight:800;font-size:18px;box-shadow:var(--shadow);
}
.chip.y{background:var(--yellow);color:#7a5a00}
.chip.g{background:var(--green)}
.chip.p{background:var(--pink)}

/* ===== 练习区（引擎渲染） ===== */
.quiz-head{text-align:center;margin:26px 0 4px}
.quiz-head h2{font-size:22px;margin:0}
.quiz-head p{margin:4px 0 0;color:var(--ink-soft)}
.qcard{
  background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);
  padding:18px;margin:16px 0;border:1px solid var(--line);
}
.qnum{
  display:inline-block;background:var(--purple);color:#fff;border-radius:999px;
  font-size:14px;font-weight:800;padding:3px 12px;margin-bottom:8px;
}
.qtext{font-size:18px;font-weight:700;margin:4px 0 14px}
.qtext .big{font-size:22px;color:var(--purple-d)}
.opts{display:grid;gap:10px}
.opt{
  display:flex;align-items:center;gap:10px;width:100%;text-align:left;
  background:#faf6ff;border:2px solid var(--line);border-radius:14px;
  padding:14px 16px;font-size:18px;font-weight:600;color:var(--ink);
  cursor:pointer;transition:transform .08s;
}
.opt:active{transform:scale(.98)}
.opt .key{
  flex:none;width:30px;height:30px;border-radius:50%;background:#fff;
  border:2px solid var(--purple);color:var(--purple-d);font-weight:800;
  display:flex;align-items:center;justify-content:center;font-size:15px;
}
.opt.correct{background:#e6fbf0;border-color:var(--green);}
.opt.correct .key{background:var(--green);border-color:var(--green);color:#fff}
.opt.wrong{background:#fff0f0;border-color:var(--red);animation:shake .35s}
.opt.wrong .key{background:var(--red);border-color:var(--red);color:#fff}
.opt.lock{pointer-events:none;opacity:.85}
@keyframes shake{0%,100%{transform:translateX(0)}25%{transform:translateX(-6px)}75%{transform:translateX(6px)}}

/* 填空 */
.fill-row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.fill-row input{
  flex:1;min-width:120px;font-size:20px;font-weight:800;text-align:center;
  padding:12px;border:2px solid var(--purple);border-radius:14px;color:var(--purple-d);
}
.fill-row input:focus{outline:none;border-color:var(--pink)}

/* 排序题（按顺序点） */
.order-zone{display:grid;gap:10px}
.order-item{
  background:#faf6ff;border:2px solid var(--line);border-radius:14px;
  padding:13px 16px;font-size:18px;font-weight:700;cursor:pointer;display:flex;gap:10px;align-items:center;
}
.order-item .seq{flex:none;width:28px;height:28px;border-radius:50%;background:#eee;color:#999;display:flex;align-items:center;justify-content:center;font-size:15px;font-weight:800}
.order-item.picked{background:#e6fbf0;border-color:var(--green)}
.order-item.picked .seq{background:var(--green);color:#fff}
.order-item.lock{pointer-events:none}

/* 配对题 */
.match-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.match-col{display:grid;gap:10px}
.mitem{
  background:#faf6ff;border:2px solid var(--line);border-radius:14px;
  padding:13px;font-size:17px;font-weight:700;cursor:pointer;text-align:center;
}
.mitem.sel{border-color:var(--purple);background:#f0e6ff}
.mitem.done{background:#e6fbf0;border-color:var(--green);pointer-events:none;opacity:.7}
.mitem.bad{animation:shake .35s;border-color:var(--red)}

/* 反馈条 */
.fb{margin-top:12px;border-radius:12px;padding:12px 14px;font-weight:700;font-size:16px;display:none}
.fb.show{display:block;animation:pop .25s}
.fb.ok{background:#e6fbf0;color:var(--green-d)}
.fb.no{background:#fff3e0;color:#c47a00}
@keyframes pop{from{transform:scale(.95);opacity:.4}to{transform:scale(1);opacity:1}}

.qbtn{
  margin-top:12px;background:var(--purple);color:#fff;border:none;border-radius:14px;
  padding:12px 20px;font-size:17px;font-weight:800;cursor:pointer;width:100%;
}
.qbtn:active{transform:scale(.98)}
.qbtn.ghost{background:#eee;color:var(--ink-soft)}

/* 结尾 */
.finish{
  text-align:center;background:linear-gradient(135deg,#fff4c2,#ffd9ef);
  border:none;display:none;
}
.finish.show{display:block;animation:pop .3s}
.finish .bigstar{font-size:54px;margin:4px 0}
.finish h2{margin:6px 0;font-size:24px}
.finish .score{font-size:20px;font-weight:800;color:var(--purple-d)}
.summary{
  background:#f7f3ff;border-radius:14px;padding:14px;margin:14px 0;text-align:left;font-size:16px;
}
.summary li{margin:6px 0}
.nextbtn{
  display:inline-block;background:var(--green);color:#fff;text-decoration:none;
  border-radius:999px;padding:14px 30px;font-size:18px;font-weight:800;margin-top:8px;border:none;cursor:pointer;
}
.nextbtn:active{transform:scale(.97)}

.cheer{position:fixed;left:50%;top:40%;transform:translateX(-50%);font-size:80px;z-index:50;pointer-events:none;opacity:0}
.cheer.go{animation:cheer 1s ease-out}
@keyframes cheer{0%{opacity:0;transform:translateX(-50%) scale(.3)}30%{opacity:1;transform:translateX(-50%) scale(1.2)}100%{opacity:0;transform:translateX(-50%) scale(1) translateY(-40px)}}

@media(max-width:480px){
  body{font-size:16px}
  h1.day-h{font-size:23px}
  .match-grid{gap:8px}
  .mitem{font-size:15px;padding:11px}
}