:root{
  --bg:#f4f5f9;
  --card:#ffffff;
  --ink:#15171e;
  --ink2:#5c6475;
  --ink3:#9aa2b4;
  --line:#ebedf4;
  --primary:#3f6df6;
  --primary-2:#5b86ff;
  --primary-soft:#eef2ff;
  --ok:#12a06a;
  --ok-soft:#e8f8f1;
  --bad:#e5484d;
  --bad-soft:#fdecec;
  --warn:#f59e0b;
  --radius:16px;
  --shadow:0 2px 12px rgba(23,31,56,.06);
  --shadow-lg:0 8px 28px rgba(23,31,56,.10);
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;padding:0;height:100%}
body{
  background:var(--bg);color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;
  font-size:16px;line-height:1.6;
  -webkit-font-smoothing:antialiased;
  overscroll-behavior-y:none;
}
.app{max-width:520px;margin:0 auto;min-height:100%;position:relative;background:var(--bg)}
.view{padding:0 16px calc(84px + env(safe-area-inset-bottom));min-height:100vh}
a{color:inherit;text-decoration:none}
button{font-family:inherit}

/* ---------- top bar ---------- */
.topbar{
  position:sticky;top:0;z-index:30;display:flex;align-items:center;gap:10px;
  padding:calc(10px + env(safe-area-inset-top)) 0 10px;background:var(--bg);
}
.topbar h1{font-size:17px;margin:0;font-weight:650;letter-spacing:.2px}
.topbar .spacer{flex:1}
.icon-btn{
  width:36px;height:36px;border-radius:12px;border:1px solid var(--line);background:#fff;
  display:flex;align-items:center;justify-content:center;color:var(--ink2);cursor:pointer;
}
.icon-btn svg{width:18px;height:18px;fill:currentColor}
.back-btn{border:none;background:transparent;padding:0 4px;color:var(--ink);font-size:15px;display:flex;align-items:center;gap:4px;cursor:pointer}
.back-btn svg{width:20px;height:20px;fill:var(--ink)}

/* ---------- home hero ---------- */
.hero{
  margin-top:6px;border-radius:22px;padding:20px;color:#fff;position:relative;overflow:hidden;
  background:linear-gradient(135deg,#4a6cf7 0%,#5f8bff 55%,#7aa2ff 100%);
  box-shadow:0 10px 26px rgba(74,108,247,.28);
}
.hero:after{content:"";position:absolute;right:-40px;top:-60px;width:180px;height:180px;border-radius:50%;background:rgba(255,255,255,.12)}
.hero:before{content:"";position:absolute;right:36px;bottom:-70px;width:130px;height:130px;border-radius:50%;background:rgba(255,255,255,.10)}
.hero h2{margin:0 0 6px;font-size:20px;font-weight:700;letter-spacing:.5px}
.hero p{margin:0;font-size:13px;opacity:.88}
.hero-stats{display:flex;gap:22px;margin-top:16px;position:relative;z-index:1}
.hero-stats div{display:flex;flex-direction:column}
.hero-stats b{font-size:19px;font-weight:700;letter-spacing:.4px}
.hero-stats span{font-size:11px;opacity:.82;margin-top:2px}
.hero .today{margin:12px 0 0;font-size:12px;opacity:.92;position:relative;z-index:1}

/* ---------- section ---------- */
.section{margin-top:22px}
.section-head{display:flex;align-items:baseline;justify-content:space-between;margin-bottom:10px}
.section-head h3{margin:0;font-size:15px;font-weight:650}
.section-head span{font-size:12px;color:var(--ink3)}

/* ---------- mode cards ---------- */
.mode-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.mode-card{
  background:var(--card);border-radius:var(--radius);padding:16px 14px;box-shadow:var(--shadow);
  display:flex;flex-direction:column;gap:6px;cursor:pointer;border:1px solid rgba(235,237,244,.9);
  transition:transform .12s ease;
}
.mode-card:active{transform:scale(.985)}
.mode-card .emoji{font-size:22px;line-height:1}
.mode-card b{font-size:15px;font-weight:650}
.mode-card small{font-size:12px;color:var(--ink3);line-height:1.5}

/* ---------- module list ---------- */
.module-list{background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);overflow:hidden}
.module-item{
  display:flex;align-items:center;gap:12px;padding:14px 16px;cursor:pointer;
  border-bottom:1px solid var(--line);
}
.module-item:last-child{border-bottom:none}
.module-item:active{background:#fafbff}
.module-ico{
  width:38px;height:38px;border-radius:12px;display:flex;align-items:center;justify-content:center;
  font-size:15px;font-weight:700;color:#fff;flex:0 0 auto;
}
.module-item .info{flex:1;min-width:0}
.module-item .info b{display:block;font-size:15px;font-weight:600}
.module-item .info small{display:block;font-size:11.5px;color:var(--ink3);margin-top:2px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.module-item .arrow{color:#c6ccdb;font-size:18px}
.chev{width:16px;height:16px;fill:#c6ccdb}
svg.st path{fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
svg.st{color:#8d95a8}
.chev.st{color:#c6ccdb}

/* 真题里的填空线 */
.blank{
  display:inline-block;height:1.02em;vertical-align:-.16em;
  border-bottom:1.6px solid #b9c0d0;margin:0 .1em;border-radius:1px;
}
.badge[hidden]{display:none}
.toast[hidden]{display:none}

/* ---------- chips ---------- */
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{
  padding:8px 14px;border-radius:999px;background:#fff;border:1px solid var(--line);
  font-size:13.5px;color:var(--ink2);cursor:pointer;box-shadow:0 1px 3px rgba(23,31,56,.03);
}
.chip.active{background:var(--primary);border-color:var(--primary);color:#fff;box-shadow:0 4px 12px rgba(63,109,246,.28)}
.chip small{opacity:.6;margin-left:4px;font-size:11px}

/* ---------- quiz ---------- */
.quiz-head{display:flex;align-items:center;gap:12px;padding-top:calc(10px + env(safe-area-inset-top))}
.progress{flex:1;height:6px;border-radius:99px;background:#e6e9f2;overflow:hidden}
.progress i{display:block;height:100%;background:linear-gradient(90deg,var(--primary),var(--primary-2));border-radius:99px;transition:width .28s ease}
.counter{font-size:12.5px;color:var(--ink3);font-variant-numeric:tabular-nums;min-width:44px;text-align:right}

.q-meta{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin:16px 0 10px}
.tag{font-size:11.5px;padding:3px 9px;border-radius:8px;background:var(--primary-soft);color:var(--primary);font-weight:600}
.tag.gray{background:#f1f3f8;color:var(--ink2);font-weight:500}
.tag.multi{background:#fff4e6;color:#c2740b}

.material-box{margin-bottom:12px}
.material{
  background:#fbfbfd;border:1px solid var(--line);border-radius:14px;padding:12px 14px;
  font-size:14px;color:var(--ink2);line-height:1.75;position:relative;
}
.material h4{margin:0 0 6px;font-size:12px;color:var(--ink3);font-weight:600;letter-spacing:.4px}
.material.collapsed{max-height:140px;overflow:hidden}
.material:not(.collapsed){overflow-x:auto}
.material img{max-width:100%;height:auto;display:inline-block;vertical-align:middle}
.material table{max-width:100%;border-collapse:collapse;font-size:13px}
.material td,.material th{border:1px solid #e3e7f0;padding:4px 8px}
.material p{margin:0 0 8px}
.material p:last-child{margin-bottom:0}
.material.collapsed:after{
  content:"";position:absolute;left:0;right:0;bottom:0;height:52px;
  background:linear-gradient(to bottom,rgba(251,251,253,0),#fbfbfd 85%);border-radius:0 0 14px 14px;
}
.fold{
  display:block;width:100%;margin-top:8px;padding:8px;border:1px dashed #d7dcea;background:#fff;
  border-radius:10px;font-size:12.5px;color:var(--primary);font-weight:600;cursor:pointer;
}

.q-stem{font-size:16.5px;line-height:1.75;color:var(--ink);margin:0 0 14px;word-break:break-word}
.q-stem img{max-width:100%;height:auto;vertical-align:middle;border-radius:6px}
.q-stem p{margin:0 0 8px}
.q-stem p:last-child{margin-bottom:0}

.opts{display:flex;flex-direction:column;gap:10px}
.opt{
  display:flex;gap:10px;align-items:flex-start;padding:12px 14px;border-radius:14px;background:#fff;
  border:1.5px solid var(--line);cursor:pointer;transition:all .14s ease;box-shadow:0 1px 4px rgba(23,31,56,.03);
}
.opt:active{transform:scale(.995)}
.opt .key{
  width:22px;height:22px;border-radius:8px;background:#f2f4f9;color:var(--ink2);font-size:12.5px;font-weight:700;
  display:flex;align-items:center;justify-content:center;flex:0 0 auto;margin-top:1px;
}
.opt .txt{flex:1;font-size:15px;line-height:1.65;color:var(--ink);word-break:break-word}
.opt .txt img{max-width:100%;height:auto;vertical-align:middle}
.opt .txt p{margin:0}
.opt.picked{border-color:var(--primary);background:#f7f9ff}
.opt.picked .key{background:var(--primary);color:#fff}
.opt.correct{border-color:var(--ok);background:var(--ok-soft)}
.opt.correct .key{background:var(--ok);color:#fff}
.opt.wrong{border-color:var(--bad);background:var(--bad-soft)}
.opt.wrong .key{background:var(--bad);color:#fff}
.opt.locked{cursor:default}

.feedback{margin-top:16px;animation:rise .22s ease}
@keyframes rise{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}
.fb-head{display:flex;align-items:center;gap:8px;font-size:14.5px;font-weight:650;margin-bottom:8px}
.fb-head .dot{width:8px;height:8px;border-radius:50%}
.fb-head.ok{color:var(--ok)}
.fb-head.ok .dot{background:var(--ok)}
.fb-head.bad{color:var(--bad)}
.fb-head.bad .dot{background:var(--bad)}
.analysis{
  background:#fff;border-radius:var(--radius);padding:14px 16px;box-shadow:var(--shadow);
  font-size:14.5px;line-height:1.8;color:#2c3140;word-break:break-word;
}
.analysis h5{margin:0 0 6px;font-size:12px;color:var(--ink3);letter-spacing:.4px;font-weight:600}
.analysis img{max-width:100%;height:auto;vertical-align:middle;border-radius:6px;margin:4px 0}
.analysis p{margin:0 0 8px}
.analysis p:last-child{margin-bottom:0}
.analysis strong{color:var(--ink)}
.answer-line{display:flex;gap:16px;margin-bottom:10px;font-size:13.5px;color:var(--ink2);flex-wrap:wrap}
.answer-line b{color:var(--ink);font-weight:650}

/* ---------- action bar ---------- */
.action-bar{
  position:fixed;left:0;right:0;bottom:0;z-index:40;padding:10px 16px calc(10px + env(safe-area-inset-bottom));
  background:linear-gradient(to top,rgba(244,245,249,.98),rgba(244,245,249,.86) 70%,rgba(244,245,249,0));
  max-width:520px;margin:0 auto;
}
.btn{
  width:100%;border:none;border-radius:14px;padding:14px;font-size:16px;font-weight:650;color:#fff;
  background:linear-gradient(135deg,var(--primary),var(--primary-2));box-shadow:0 6px 18px rgba(63,109,246,.28);
  cursor:pointer;
}
.btn:active{transform:scale(.99)}
.btn.ghost{background:#fff;color:var(--ink);border:1px solid var(--line);box-shadow:none}
.btn.danger{background:#fff;color:var(--bad);border:1px solid #f6d5d6;box-shadow:none}
.btn:disabled{opacity:.5}
.btn-row{display:flex;gap:10px}
.btn-row .btn{flex:1}

/* ---------- result ---------- */
.result-card{
  background:#fff;border-radius:22px;padding:22px 18px;box-shadow:var(--shadow);text-align:center;margin-top:12px;
}
.donut{width:190px;height:190px;margin:0 auto;position:relative}
.donut svg{transform:rotate(-90deg)}
.donut .center{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center}
.donut .center b{font-size:32px;font-weight:700;letter-spacing:.5px;line-height:1.1}
.donut .center span{font-size:12px;color:var(--ink3);margin-top:2px}
.legend{display:flex;justify-content:center;gap:26px;margin-top:16px}
.legend div{display:flex;align-items:center;gap:7px;font-size:13px;color:var(--ink2)}
.legend i{width:9px;height:9px;border-radius:3px;display:inline-block}
.legend b{color:var(--ink);font-weight:650;font-variant-numeric:tabular-nums}
.result-meta{display:flex;justify-content:space-around;margin-top:18px;padding-top:16px;border-top:1px solid var(--line)}
.result-meta div{display:flex;flex-direction:column;align-items:center;gap:3px}
.result-meta b{font-size:16px;font-weight:650}
.result-meta span{font-size:11.5px;color:var(--ink3)}
.verdict{margin-top:14px;font-size:14px;color:var(--ink2)}
.verdict b{color:var(--primary)}

/* ---------- list rows (wrong / history) ---------- */
.rows{background:#fff;border-radius:var(--radius);box-shadow:var(--shadow);overflow:hidden}
.row{padding:14px 16px;border-bottom:1px solid var(--line);cursor:pointer;display:flex;gap:12px;align-items:flex-start}
.row:last-child{border-bottom:none}
.row:active{background:#fafbff}
.row .idx{
  width:26px;height:26px;border-radius:9px;background:#f2f4f9;color:var(--ink2);font-size:12px;font-weight:700;
  display:flex;align-items:center;justify-content:center;flex:0 0 auto;margin-top:2px;
}
.row .idx.ok{background:var(--ok-soft);color:var(--ok)}
.row .idx.bad{background:var(--bad-soft);color:var(--bad)}
.row .body{flex:1;min-width:0}
.row .body .t{font-size:14.5px;line-height:1.55;color:var(--ink);display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.row .body .meta{font-size:11.5px;color:var(--ink3);margin-top:5px;display:flex;gap:8px;flex-wrap:wrap}
.row .body .meta em{font-style:normal;color:var(--ink2)}

.empty{text-align:center;padding:56px 20px;color:var(--ink3)}
.empty .ico{font-size:40px;margin-bottom:10px}
.empty p{margin:0 0 4px;font-size:14px}
.empty small{font-size:12.5px;opacity:.8}

.stat-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-top:12px}
.stat-box{background:#fff;border-radius:14px;padding:14px 10px;text-align:center;box-shadow:var(--shadow)}
.stat-box b{display:block;font-size:19px;font-weight:700;letter-spacing:.3px}
.stat-box span{font-size:11.5px;color:var(--ink3)}

.bar-list{background:#fff;border-radius:var(--radius);padding:16px;box-shadow:var(--shadow);margin-top:12px}
.bar-item{margin-bottom:14px}
.bar-item:last-child{margin-bottom:0}
.bar-item .l{display:flex;justify-content:space-between;font-size:13px;color:var(--ink2);margin-bottom:6px}
.bar-item .l b{color:var(--ink);font-weight:600}
.bar-track{height:8px;border-radius:99px;background:#f1f3f8;overflow:hidden}
.bar-track i{display:block;height:100%;border-radius:99px;background:linear-gradient(90deg,var(--primary),var(--primary-2))}

/* ---------- tabbar ---------- */
.tabbar{
  position:fixed;bottom:0;left:0;right:0;z-index:50;max-width:520px;margin:0 auto;
  display:flex;background:rgba(255,255,255,.94);backdrop-filter:blur(14px);
  border-top:1px solid var(--line);padding:6px 0 calc(6px + env(safe-area-inset-bottom));
}
.tab{flex:1;display:flex;flex-direction:column;align-items:center;gap:3px;padding:6px 0;color:var(--ink3);font-size:11px;position:relative}
.tab svg{width:21px;height:21px;fill:currentColor;opacity:.85}
.tab.active{color:var(--primary)}
.tab.active svg{opacity:1}
.badge{
  position:absolute;top:2px;left:calc(50% + 8px);min-width:16px;height:16px;border-radius:99px;background:var(--bad);
  color:#fff;font-size:10px;font-style:normal;display:flex;align-items:center;justify-content:center;padding:0 4px;
}
body.no-tab .tabbar{display:none}
body.no-tab .view{padding-bottom:24px}

/* ---------- toast ---------- */
.toast{
  position:fixed;left:50%;bottom:96px;transform:translateX(-50%);background:rgba(24,28,38,.9);color:#fff;
  padding:10px 16px;border-radius:12px;font-size:13.5px;z-index:99;max-width:80%;text-align:center;
  animation:rise .2s ease;
}

.loading{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:80px 0;color:var(--ink3);font-size:13.5px;gap:14px}
.spinner{width:26px;height:26px;border:2.5px solid #e3e7f1;border-top-color:var(--primary);border-radius:50%;animation:spin .8s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}

.hint{font-size:12px;color:var(--ink3);line-height:1.7;margin-top:10px}
.divider{height:1px;background:var(--line);margin:16px 0}