/* ===== 数学游乐园 共享样式 卡通活泼风 ===== */
@import url('https://fonts.googleapis.com/css2?family=ZCOOL+KuaiLe&family=Baloo+2:wght@500;700;800&display=swap');

:root{
  --bg1:#fff7e6;
  --bg2:#e6f7ff;
  --c-red:#ff6b6b;
  --c-orange:#ffa94d;
  --c-yellow:#ffd43b;
  --c-green:#51cf66;
  --c-teal:#20c997;
  --c-blue:#4dabf7;
  --c-indigo:#748ffc;
  --c-purple:#cc5de8;
  --c-pink:#f783ac;
  --ink:#3a3a5c;
  --ink-soft:#6b6b8a;
  --paper:#ffffff;
  --shadow:0 8px 0 rgba(0,0,0,.08), 0 14px 24px rgba(0,0,0,.12);
  --shadow-sm:0 4px 0 rgba(0,0,0,.08), 0 8px 16px rgba(0,0,0,.10);
  --radius:26px;
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:'Baloo 2','ZCOOL KuaiLe',system-ui,-apple-system,'PingFang SC','Microsoft YaHei',sans-serif;
  color:var(--ink);
  background:
    radial-gradient(circle at 15% 10%, #fff0f6 0, transparent 35%),
    radial-gradient(circle at 85% 15%, #e6fcf5 0, transparent 35%),
    radial-gradient(circle at 50% 100%, #e7f5ff 0, transparent 45%),
    linear-gradient(160deg,var(--bg1),var(--bg2));
  background-attachment:fixed;
  min-height:100vh;
  line-height:1.6;
}
h1,h2,h3,.zcool{font-family:'ZCOOL KuaiLe','Baloo 2',cursive}

/* 顶部导航 */
.topbar{
  position:sticky;top:0;z-index:50;
  display:flex;align-items:center;gap:14px;
  padding:14px 24px;
  background:rgba(255,255,255,.82);
  backdrop-filter:blur(8px);
  border-bottom:4px solid #ffe3a3;
}
.topbar .logo{font-family:'ZCOOL KuaiLe';font-size:26px;color:var(--c-red);text-decoration:none}
.topbar .logo span{color:var(--c-blue)}
.topbar .home-link{
  margin-left:auto;text-decoration:none;font-weight:700;
  background:var(--c-yellow);color:var(--ink);
  padding:8px 18px;border-radius:999px;box-shadow:var(--shadow-sm);
  transition:transform .15s;
}
.topbar .home-link:hover{transform:translateY(-2px) rotate(-2deg)}

.wrap{max-width:1080px;margin:0 auto;padding:28px 20px 80px}

/* 首页 Hero */
.hero{
  text-align:center;padding:42px 20px 20px;
}
.hero h1{font-size:clamp(34px,6vw,60px);color:var(--c-purple);text-shadow:3px 3px 0 #fff,5px 5px 0 rgba(204,93,232,.25)}
.hero p{font-size:clamp(15px,2.6vw,20px);color:var(--ink-soft);margin-top:10px}
.hero .badge{
  display:inline-block;margin-top:16px;background:#fff;
  padding:8px 20px;border-radius:999px;box-shadow:var(--shadow-sm);
  font-weight:700;color:var(--c-teal);border:3px dashed #b2f2bb;
}

/* 单元卡片网格 */
.grid{
  display:grid;gap:22px;margin-top:34px;
  grid-template-columns:repeat(auto-fill,minmax(250px,1fr));
}
.unit-card{
  display:block;text-decoration:none;color:var(--ink);
  background:var(--paper);border-radius:var(--radius);
  padding:22px;box-shadow:var(--shadow);
  border:5px solid #fff;position:relative;overflow:hidden;
  transition:transform .18s,box-shadow .18s;
}
.unit-card:hover{transform:translateY(-6px) rotate(-1deg)}
.unit-card .emoji{font-size:46px;display:block}
.unit-card .num{
  position:absolute;top:14px;right:18px;font-family:'ZCOOL KuaiLe';
  font-size:40px;color:rgba(0,0,0,.07)
}
.unit-card h3{font-size:22px;margin:10px 0 6px}
.unit-card p{font-size:14px;color:var(--ink-soft);min-height:42px}
.unit-card .go{
  display:inline-block;margin-top:12px;font-weight:700;
  color:#fff;padding:6px 16px;border-radius:999px;font-size:14px;
}
.unit-card .bar{height:8px;border-radius:999px;margin-top:14px;opacity:.9}

/* 单元页通用 */
.unit-hero{
  text-align:center;color:#fff;border-radius:var(--radius);
  padding:30px 22px;box-shadow:var(--shadow);margin-bottom:26px;
}
.unit-hero .emoji{font-size:54px}
.unit-hero h1{font-size:clamp(28px,5vw,44px);text-shadow:2px 2px 0 rgba(0,0,0,.15)}
.unit-hero p{opacity:.95;margin-top:6px;font-size:16px}

.section-title{
  font-size:26px;color:var(--ink);margin:30px 0 14px;
  display:flex;align-items:center;gap:10px
}
.section-title::before{content:"";width:14px;height:30px;border-radius:6px;background:var(--c-orange)}
.section-title.game::before{background:var(--c-green)}

.card{
  background:var(--paper);border-radius:var(--radius);
  padding:24px;box-shadow:var(--shadow-sm);border:4px solid #fff;
  margin-bottom:20px;
}
.kp{/* knowledge point block */}
.kp h4{font-size:19px;color:var(--c-blue);margin-bottom:8px}
.kp p{color:var(--ink-soft);margin-bottom:8px}
.tip{
  background:#fff9db;border-left:6px solid var(--c-yellow);
  padding:12px 16px;border-radius:12px;margin:10px 0;color:#7a6a1f;font-weight:600
}
.formula{
  background:#e7f5ff;border:3px dashed #74c0fc;border-radius:14px;
  padding:14px;text-align:center;font-size:20px;font-weight:700;color:#1971c2;margin:10px 0
}

/* 按钮 */
.btn{
  font-family:inherit;font-weight:700;cursor:pointer;border:none;
  padding:12px 26px;border-radius:999px;font-size:17px;color:#fff;
  background:var(--c-blue);box-shadow:0 5px 0 rgba(0,0,0,.15);
  transition:transform .1s;user-select:none;
}
.btn:active{transform:translateY(4px);box-shadow:0 1px 0 rgba(0,0,0,.15)}
.btn.green{background:var(--c-green)}
.btn.orange{background:var(--c-orange)}
.btn.red{background:var(--c-red)}
.btn.purple{background:var(--c-purple)}
.btn.gray{background:#adb5bd}
.btn:disabled{background:#ced4da;box-shadow:none;cursor:default;transform:none}

/* 游戏区 */
.game{
  background:linear-gradient(160deg,#fff,#f8f9ff);
  border-radius:var(--radius);padding:24px;border:4px solid #fff;
  box-shadow:var(--shadow);
}
.game-hud{
  display:flex;flex-wrap:wrap;gap:12px;align-items:center;
  justify-content:space-between;margin-bottom:16px
}
.hud-pill{
  background:#fff;border-radius:999px;padding:8px 18px;font-weight:700;
  box-shadow:var(--shadow-sm);display:flex;align-items:center;gap:8px
}
.hud-pill b{color:var(--c-red)}
.game-stage{
  min-height:180px;display:flex;flex-direction:column;align-items:center;
  justify-content:center;gap:16px;text-align:center
}
.feedback{font-size:22px;font-weight:700;min-height:30px}
.feedback.ok{color:var(--c-green)}
.feedback.no{color:var(--c-red)}

.choices{display:flex;flex-wrap:wrap;gap:12px;justify-content:center}
.choice{
  background:#fff;border:3px solid #dee2e6;border-radius:16px;
  padding:14px 22px;font-size:20px;font-weight:700;cursor:pointer;
  box-shadow:var(--shadow-sm);transition:transform .1s,border-color .1s
}
.choice:hover{transform:translateY(-3px);border-color:var(--c-blue)}
.choice.correct{background:#d3f9d8;border-color:var(--c-green)}
.choice.wrong{background:#ffe3e3;border-color:var(--c-red)}

.progress{height:14px;background:#e9ecef;border-radius:999px;overflow:hidden;margin-top:14px}
.progress>i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--c-green),var(--c-teal));transition:width .3s}

/* 弹跳/抖动动画 */
@keyframes pop{0%{transform:scale(.6);opacity:0}60%{transform:scale(1.15)}100%{transform:scale(1);opacity:1}}
@keyframes shake{0%,100%{transform:translateX(0)}25%{transform:translateX(-8px)}75%{transform:translateX(8px)}}
.pop{animation:pop .35s}
.shake{animation:shake .35s}

.win-banner{
  background:linear-gradient(135deg,var(--c-yellow),var(--c-orange));
  color:#fff;border-radius:18px;padding:18px;font-size:22px;font-weight:800;
  box-shadow:var(--shadow-sm);animation:pop .4s
}

.footer{text-align:center;color:var(--ink-soft);font-size:13px;padding:30px 0 10px}

/* 通用工具 */
.center{text-align:center}
.row{display:flex;flex-wrap:wrap;gap:14px}
.muted{color:var(--ink-soft)}

/* ===== 响应式：兼容 PC / 平板 / 手机 ===== */
html,body{overflow-x:hidden;-webkit-text-size-adjust:100%}
img,svg,canvas{max-width:100%;height:auto}
input[type=range]{max-width:100%}
button,.btn,.choice,.unit-card,a{-webkit-tap-highlight-color:rgba(0,0,0,.08);touch-action:manipulation}

/* 平板及以下 */
@media (max-width:900px){
  .wrap{padding:22px 16px 70px}
  .grid{gap:18px}
}

/* 手机 */
@media (max-width:600px){
  .topbar{padding:10px 14px;gap:8px}
  .topbar .logo{font-size:21px}
  .topbar .home-link{padding:7px 14px;font-size:14px}
  .wrap{padding:18px 12px 60px}
  .hero{padding:26px 8px 10px}
  .grid{grid-template-columns:1fr;gap:16px}
  .unit-card{padding:18px}
  .unit-card .num{font-size:34px}
  .unit-hero{padding:24px 16px}
  .unit-hero .emoji{font-size:44px}
  .section-title{font-size:21px;margin:24px 0 12px}
  .card,.game{padding:16px;border-radius:20px}
  .formula{font-size:17px;padding:12px}
  .btn{padding:11px 20px;font-size:16px}
  .game-hud{gap:8px}
  .hud-pill{padding:7px 13px;font-size:14px}
  .choice{padding:12px 16px;font-size:18px}
  .choices{gap:10px}
  .row{flex-direction:column}
  .row>*{width:100%}
  .win-banner{font-size:19px;padding:14px}
  .row{gap:8px}
}

/* 极窄屏 */
@media (max-width:360px){
  .unit-hero h1{font-size:26px}
  .choice{font-size:16px;padding:10px 12px}
}