/* ===========================================================
   刷题宝 · 样式
   iOS 风格 / iPhone + iPad 自适应 / 支持深浅色
   =========================================================== */

:root{
  --brand:#2F6BFF;
  --brand-deep:#1E4FD8;
  --brand-soft:#EBF1FF;
  --brand-soft-2:#DCE7FF;
  --bg:#F2F4F8;
  --bg-blur:rgba(242,244,248,.88);
  --card:#FFFFFF;
  --card-2:#FAFBFD;
  --text:#0E1726;
  --text-2:#5A6678;
  --text-3:#8A94A6;
  --line:#E7EBF1;
  --green:#12B76A;
  --green-soft:#E8F8F0;
  --red:#F04438;
  --red-soft:#FDECEA;
  --amber:#F79009;
  --amber-soft:#FEF3E2;
  --shadow:0 1px 2px rgba(16,24,40,.04), 0 10px 28px -18px rgba(16,24,40,.28);
  --shadow-lg:0 18px 50px -18px rgba(16,24,40,.26);
  --safe-t:env(safe-area-inset-top, 0px);
  --safe-b:env(safe-area-inset-bottom, 0px);
  --r-xl:24px;
  --r-lg:20px;
  --r-md:14px;
  --r-sm:10px;
  --tab-h:64px;
}

@media (prefers-color-scheme: dark){
  :root{
    --brand:#5B8CFF;
    --brand-deep:#7FA5FF;
    --brand-soft:#16233D;
    --brand-soft-2:#1D2C4A;
    --bg:#0B0F17;
    --bg-blur:rgba(11,15,23,.86);
    --card:#141A24;
    --card-2:#101620;
    --text:#F1F5FB;
    --text-2:#A6B2C4;
    --text-3:#6E7C90;
    --line:#232C3A;
    --green:#32D583;
    --green-soft:#0F2A1F;
    --red:#FF7A6E;
    --red-soft:#2A1513;
    --amber:#FDB022;
    --amber-soft:#2A1F0B;
    --shadow:0 1px 2px rgba(0,0,0,.3);
    --shadow-lg:0 20px 50px -20px rgba(0,0,0,.7);
  }
}

*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
[hidden]{display:none !important}
html{height:100%}
body{
  margin:0;
  min-height:100%;
  background:var(--bg);
  color:var(--text);
  font-family:-apple-system,BlinkMacSystemFont,"SF Pro SC","SF Pro Text","PingFang SC","Hiragino Sans GB","Helvetica Neue",Arial,sans-serif;
  font-size:17px;
  line-height:1.5;
  -webkit-font-smoothing:antialiased;
  -webkit-text-size-adjust:100%;
  overscroll-behavior-y:none;
}
body.lock{overflow:hidden}
button{font:inherit;color:inherit;border:0;background:none;padding:0;cursor:pointer;touch-action:manipulation;text-align:inherit}
input,textarea,select{font:inherit;color:inherit;-webkit-appearance:none;appearance:none}
h1,h2,h3,h4,p{margin:0}
ul{margin:0;padding:0;list-style:none}
svg{display:block}
::selection{background:var(--brand-soft-2)}

/* ---------- 布局 ---------- */
.main{
  padding:calc(var(--safe-t) + 10px) 18px calc(var(--tab-h) + 40px + var(--safe-b));
  max-width:880px;
  margin:0 auto;
  min-height:100dvh;
}
.screen{animation:screenIn .32s cubic-bezier(.22,.8,.24,1)}
@keyframes screenIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}

/* ---------- 通用元素 ---------- */
.h1{font-size:29px;line-height:1.2;font-weight:800;letter-spacing:-.6px}
.h2{font-size:18px;font-weight:700;letter-spacing:-.2px}
.eyebrow{font-size:12.5px;font-weight:600;color:var(--text-3);letter-spacing:.4px}
.muted{color:var(--text-3);font-size:13px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r-lg);box-shadow:var(--shadow)}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:7px;
  height:46px;padding:0 18px;border-radius:14px;font-size:16px;font-weight:650;
  transition:transform .14s ease,opacity .14s ease,background .16s ease;
  white-space:nowrap;
}
.btn:active{transform:scale(.975)}
.btn:disabled{opacity:.4;pointer-events:none}
.btn-primary{background:var(--brand);color:#fff;box-shadow:0 8px 18px -10px rgba(47,107,255,.9)}
.btn-primary:active{background:var(--brand-deep)}
.btn-soft{background:var(--brand-soft);color:var(--brand)}
.btn-ghost{background:var(--card);border:1px solid var(--line);color:var(--text)}
.btn-danger{background:var(--red-soft);color:var(--red)}
.btn-sm{height:36px;padding:0 14px;border-radius:11px;font-size:14px}
.btn-block{display:flex;width:100%}
.flex{flex:1}

.icon-btn{
  width:38px;height:38px;border-radius:50%;display:grid;place-items:center;
  color:var(--text-2);background:var(--card);border:1px solid var(--line);
  transition:transform .14s,background .16s;
  flex:none;
}
.icon-btn:active{transform:scale(.92);background:var(--card-2)}
.icon-btn.sm{width:32px;height:32px;border:0;background:transparent;color:var(--text-3)}
.icon-btn.plain{border:0;background:transparent}

.chip{
  display:inline-flex;align-items:center;height:24px;padding:0 9px;border-radius:7px;
  font-size:12px;font-weight:650;letter-spacing:.2px;
  background:var(--brand-soft);color:var(--brand);
}
.chip.gray{background:var(--card-2);color:var(--text-3);border:1px solid var(--line)}
.chip.green{background:var(--green-soft);color:var(--green)}
.chip.red{background:var(--red-soft);color:var(--red)}

.progress{height:6px;border-radius:99px;background:var(--line);overflow:hidden}
.progress>i{display:block;height:100%;border-radius:99px;background:linear-gradient(90deg,var(--brand),#7EA2FF);transition:width .4s ease}

.section-head{display:flex;align-items:center;justify-content:space-between;gap:12px;margin:26px 2px 12px}
.section-head h2{font-size:19px;font-weight:750;letter-spacing:-.2px}

/* ---------- 顶栏 / 导航 ---------- */
.home-head{display:flex;align-items:flex-start;justify-content:space-between;gap:14px;padding:6px 2px 18px}
.home-head .h1{margin-top:4px}

.nav-bar{
  display:flex;align-items:center;gap:10px;
  padding:calc(var(--safe-t) + 8px) 0 14px;
  position:sticky;top:0;z-index:20;
  background:var(--bg-blur);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);
  margin:0 -18px 6px;padding-left:18px;padding-right:18px;
}
.nav-title{font-size:17px;font-weight:700;flex:1;text-align:center;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;padding-right:38px}
.nav-title.with-actions{padding-right:0}

/* ---------- 底部标签栏 ---------- */
.tabbar{
  position:fixed;left:0;right:0;bottom:0;z-index:40;
  height:calc(var(--tab-h) + var(--safe-b));
  padding-bottom:var(--safe-b);
  display:flex;align-items:stretch;
  background:rgba(255,255,255,.9);
  backdrop-filter:blur(20px) saturate(170%);
  -webkit-backdrop-filter:blur(20px) saturate(170%);
  border-top:1px solid var(--line);
}
@media (prefers-color-scheme:dark){
  .tabbar{background:rgba(20,26,36,.9)}
}
.tab{
  flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;
  gap:4px;color:var(--text-3);font-size:10.5px;font-weight:600;letter-spacing:.2px;
  transition:color .16s;
}
.tab .tab-ico{display:block;width:23px;height:23px}
.tab .tab-label{line-height:1;white-space:nowrap}
.tab.active{color:var(--brand)}

/* ---------- 首页 Hero ---------- */
.hero{
  position:relative;overflow:hidden;
  background:linear-gradient(140deg,#3D74FF 0%,#2F6BFF 42%,#5A5BFF 100%);
  border-radius:var(--r-xl);
  padding:20px;
  color:#fff;
  box-shadow:0 20px 40px -24px rgba(47,107,255,.85);
}
.hero::after{
  content:"";position:absolute;right:-56px;top:-72px;width:210px;height:210px;border-radius:50%;
  background:radial-gradient(circle at 30% 30%,rgba(255,255,255,.32),rgba(255,255,255,0) 68%);
}
.hero-top{display:flex;align-items:center;justify-content:space-between;font-size:12.5px;font-weight:600;letter-spacing:.3px;color:rgba(255,255,255,.82)}
.hero-num{font-size:46px;font-weight:800;line-height:1.1;margin:6px 0 2px;letter-spacing:-1px;font-variant-numeric:tabular-nums}
.hero-num span{font-size:15px;font-weight:600;margin-left:5px;opacity:.8;letter-spacing:0}
.hero-foot{display:flex;align-items:center;gap:22px;margin-top:16px;padding-top:14px;border-top:1px solid rgba(255,255,255,.18);position:relative;z-index:1}
.hero-foot>div{display:flex;flex-direction:column;gap:1px}
.hero-foot b{font-size:17px;font-weight:750;font-variant-numeric:tabular-nums}
.hero-foot span{font-size:11.5px;color:rgba(255,255,255,.72)}
.hero-btn{
  margin-left:auto;height:34px;padding:0 14px;border-radius:11px;
  background:rgba(255,255,255,.18);color:#fff;font-size:13px;font-weight:650;
  border:1px solid rgba(255,255,255,.28);
  backdrop-filter:blur(6px);
}
.hero-btn:active{background:rgba(255,255,255,.28)}

/* ---------- 题库列表 ---------- */
.bank-list{display:flex;flex-direction:column;gap:12px}
.bank{
  display:flex;align-items:center;gap:14px;padding:16px;width:100%;
  transition:transform .15s ease;
}
.bank:active{transform:scale(.99)}
.bank-main{flex:1;min-width:0}
.bank-name{font-size:16.5px;font-weight:700;letter-spacing:-.2px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.bank-meta{font-size:12.5px;color:var(--text-3);margin:3px 0 10px}
.bank-right{display:flex;flex-direction:column;align-items:center;gap:4px;flex:none}
.bank-pct{font-size:13px;font-weight:700;color:var(--brand);font-variant-numeric:tabular-nums}
.bank .progress{height:5px}

/* ---------- 空状态 ---------- */
.empty{text-align:center;padding:34px 24px 30px}
.empty-art{width:132px;height:132px;margin:0 auto 18px;border-radius:38px;display:grid;place-items:center;
  background:linear-gradient(150deg,var(--brand-soft),var(--card));border:1px solid var(--line);color:var(--brand);box-shadow:var(--shadow)}
.empty h3{font-size:18px;font-weight:750;margin-bottom:7px}
.empty p{font-size:14px;line-height:1.65;color:var(--text-3);max-width:300px;margin:0 auto 20px}
.empty .btn{margin:0 5px 10px}

/* ---------- 章节页 ---------- */
.feature-card{
  display:flex;align-items:center;gap:16px;width:100%;
  padding:20px;border-radius:var(--r-xl);color:#fff;
  background:linear-gradient(135deg,#2F6BFF,#5B5BFF);
  box-shadow:0 18px 36px -24px rgba(47,107,255,.9);
  position:relative;overflow:hidden;
}
.feature-card::after{content:"";position:absolute;right:-40px;bottom:-70px;width:170px;height:170px;border-radius:50%;background:rgba(255,255,255,.1)}
.feature-card:active{transform:scale(.99)}
.fc-left{flex:1;min-width:0}
.fc-title{font-size:18px;font-weight:750;letter-spacing:-.2px}
.fc-sub{font-size:12.5px;color:rgba(255,255,255,.8);margin:4px 0 12px}
.feature-card .progress{background:rgba(255,255,255,.24);height:5px}
.feature-card .progress>i{background:#fff}
.fc-play{
  width:48px;height:48px;border-radius:50%;flex:none;
  background:rgba(255,255,255,.2);border:1px solid rgba(255,255,255,.34);
  display:grid;place-items:center;
}

.list{background:var(--card);border:1px solid var(--line);border-radius:var(--r-lg);overflow:hidden;box-shadow:var(--shadow)}
.row{display:flex;align-items:center;gap:14px;width:100%;padding:15px 16px;border-bottom:1px solid var(--line);transition:background .14s}
.row:last-child{border-bottom:0}
.row:active{background:var(--card-2)}
.row-main{flex:1;min-width:0}
.row-title{font-size:16px;font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.row-sub{font-size:12.5px;color:var(--text-3);margin-top:2px}
.row .chev{color:var(--text-3);flex:none}
.ring-mini{position:relative;width:40px;height:40px;flex:none}
.ring-mini span{position:absolute;inset:0;display:grid;place-items:center;font-size:10.5px;font-weight:700;color:var(--text-2);font-variant-numeric:tabular-nums}

/* ---------- 答题页 ---------- */
body.quiz-mode .main{padding:0;max-width:none;min-height:100dvh}
body.quiz-mode .tabbar{display:none !important}

.quiz{height:100vh;height:100dvh;max-height:100dvh;display:flex;flex-direction:column;overflow:hidden;background:var(--bg)}
.quiz-head{
  position:sticky;top:0;z-index:20;
  display:flex;align-items:center;gap:10px;
  padding:calc(var(--safe-t) + 8px) 16px 10px;
  background:var(--bg-blur);backdrop-filter:blur(18px);-webkit-backdrop-filter:blur(18px);
}
.quiz-count{flex:1;text-align:center;font-size:14px;font-weight:700;font-variant-numeric:tabular-nums;letter-spacing:.2px}
.quiz-count span{color:var(--text-3);font-weight:500}
.quiz-progress{margin:0 16px 4px;height:3px;border-radius:99px;background:var(--line);overflow:hidden;flex:none}
.quiz-progress>i{display:block;height:100%;background:var(--brand);border-radius:99px;transition:width .35s ease}
.quiz-body{
  flex:1;min-height:0;width:100%;max-width:780px;margin:0 auto;
  padding:16px 18px 28px;
  overflow-y:auto;-webkit-overflow-scrolling:touch;
  overscroll-behavior:contain;
}
.q-meta{display:flex;align-items:center;gap:8px;margin-bottom:12px}
.q-chapter{font-size:12.5px;color:var(--text-3);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.stem{font-size:19px;line-height:1.62;font-weight:600;letter-spacing:-.2px;white-space:pre-wrap;word-break:break-word}
.stem .q-idx{color:var(--brand);font-weight:800;margin-right:2px}

.opts{margin-top:20px;display:flex;flex-direction:column;gap:10px}
.opt{
  display:flex;align-items:flex-start;gap:12px;width:100%;
  padding:14px 15px;border-radius:16px;
  background:var(--card);border:1.5px solid var(--line);
  transition:border-color .16s,background .16s,transform .12s;
  box-shadow:0 1px 2px rgba(16,24,40,.03);
}
.opt:active{transform:scale(.993)}
.opt-key{
  width:29px;height:29px;border-radius:50%;flex:none;
  display:grid;place-items:center;
  border:1.5px solid var(--line);
  color:var(--text-2);font-size:14px;font-weight:700;
  transition:background .16s,color .16s,border-color .16s;
}
.opts.multi .opt-key{border-radius:9px}
.opt-text{font-size:16.5px;line-height:1.6;padding-top:2px;word-break:break-word;flex:1}
.opt-mark{flex:none;width:22px;height:22px;margin-top:3px;color:var(--green);opacity:0;transition:opacity .18s}
.opt.is-picked{border-color:var(--brand);background:var(--brand-soft)}
.opt.is-picked .opt-key{background:var(--brand);border-color:var(--brand);color:#fff}
.opts.multi .opt.is-picked .opt-key{background:var(--brand);border-color:var(--brand);color:#fff}
.opt.is-right{border-color:var(--green);background:var(--green-soft)}
.opt.is-right .opt-key{background:var(--green);border-color:var(--green);color:#fff}
.opt.is-right .opt-mark{opacity:1;color:var(--green)}
.opt.is-wrong{border-color:var(--red);background:var(--red-soft)}
.opt.is-wrong .opt-key{background:var(--red);border-color:var(--red);color:#fff}
.opt.is-wrong .opt-mark{opacity:1;color:var(--red)}
.opt.is-dim{opacity:.55}
.opts.locked .opt{pointer-events:none}

.verdict{display:flex;align-items:center;gap:12px;padding:14px 15px;border-radius:16px;margin-top:18px}
.verdict.good{background:var(--green-soft)}
.verdict.bad{background:var(--red-soft)}
.verdict-ico{width:34px;height:34px;border-radius:50%;display:grid;place-items:center;background:var(--card);flex:none}
.verdict.good .verdict-ico{color:var(--green)}
.verdict.bad .verdict-ico{color:var(--red)}
.verdict b{display:block;font-size:15.5px;font-weight:750}
.verdict.good b{color:var(--green)}
.verdict.bad b{color:var(--red)}
.verdict span{font-size:12.5px;color:var(--text-2)}

.analysis{margin-top:12px;padding:16px;border-radius:16px;background:var(--card);border:1px solid var(--line)}
.analysis h4{font-size:12px;font-weight:700;color:var(--text-3);letter-spacing:.8px;margin-bottom:8px}
.analysis p{font-size:15.5px;line-height:1.75;color:var(--text-2);white-space:pre-wrap;word-break:break-word}
.analysis .ans-line{font-size:14px;color:var(--text-2);margin-bottom:8px}
.analysis .ans-line b{color:var(--green);font-weight:750}

.quiz-foot{
  position:sticky;bottom:0;z-index:20;
  display:flex;gap:10px;align-items:center;
  padding:12px 16px calc(12px + var(--safe-b));
  background:var(--bg-blur);backdrop-filter:blur(18px);-webkit-backdrop-filter:blur(18px);
  border-top:1px solid var(--line);
}
.quiz-foot .btn{height:50px;border-radius:15px}
.quiz-foot .btn-ghost{width:96px;flex:none}

/* 答题卡 */
.qgrid{display:grid;grid-template-columns:repeat(6,1fr);gap:9px;margin-top:4px}
.qnum{
  aspect-ratio:1;border-radius:12px;display:grid;place-items:center;
  background:var(--bg);color:var(--text-2);font-size:14px;font-weight:650;
  border:1.5px solid transparent;font-variant-numeric:tabular-nums;
}
.qnum.cur{border-color:var(--brand);color:var(--brand);box-shadow:0 0 0 2px var(--brand-soft)}
.qnum.ok{background:var(--green-soft);color:var(--green)}
.qnum.bad{background:var(--red-soft);color:var(--red)}
@media (min-width:600px){.qgrid{grid-template-columns:repeat(10,1fr)}}

/* ---------- 错题 / 收藏 ---------- */
.summary-strip{
  display:flex;align-items:center;gap:10px;
  padding:13px 16px;border-radius:14px;background:var(--brand-soft);
  font-size:13px;color:var(--brand-deep);font-weight:600;margin-bottom:16px;
}
.q-item{display:flex;align-items:flex-start;gap:12px;padding:15px 16px;border-bottom:1px solid var(--line);width:100%;transition:background .14s}
.q-item:last-child{border-bottom:0}
.q-item:active{background:var(--card-2)}
.q-item-main{flex:1;min-width:0}
.q-item-stem{font-size:15.5px;line-height:1.55;font-weight:550;
  display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;word-break:break-word}
.q-item-meta{display:flex;align-items:center;gap:8px;margin-top:7px;font-size:12px;color:var(--text-3)}
.q-item .icon-btn{flex:none}
.bank-group{font-size:12.5px;font-weight:700;color:var(--text-3);letter-spacing:.5px;margin:18px 4px 8px}

/* ---------- 统计 ---------- */
.stat-hero{display:flex;align-items:center;gap:20px;padding:22px 20px}
.ring-wrap{position:relative;width:124px;height:124px;flex:none}
.ring-wrap .ring-label{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:1px}
.ring-wrap .ring-label b{font-size:27px;font-weight:800;letter-spacing:-1px;font-variant-numeric:tabular-nums}
.ring-wrap .ring-label span{font-size:11px;color:var(--text-3);font-weight:600}
.stat-hero-info{flex:1;min-width:0}
.stat-hero-info h3{font-size:16px;font-weight:750;margin-bottom:6px}
.stat-hero-info p{font-size:13px;line-height:1.65;color:var(--text-3)}

.stat-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:12px}
.stat-tile{padding:16px;border-radius:var(--r-lg);background:var(--card);border:1px solid var(--line)}
.stat-tile .k{font-size:12px;color:var(--text-3);font-weight:600}
.stat-tile .v{font-size:24px;font-weight:800;margin-top:4px;letter-spacing:-.6px;font-variant-numeric:tabular-nums}
.stat-tile .v small{font-size:12px;font-weight:600;color:var(--text-3);margin-left:4px;letter-spacing:0}

.chart{display:flex;align-items:flex-end;gap:8px;height:132px;padding:10px 4px 0}
.chart-col{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:flex-end;gap:7px;height:100%}
.chart-bar{width:100%;max-width:30px;border-radius:8px;background:linear-gradient(180deg,#6F97FF,var(--brand));min-height:5px;transition:height .5s cubic-bezier(.2,.8,.2,1)}
.chart-col.today .chart-bar{background:linear-gradient(180deg,#8E7BFF,#5A5BFF)}
.chart-x{font-size:11px;color:var(--text-3);font-weight:600}
.chart-col.today .chart-x{color:var(--brand)}
.chart-val{font-size:11px;color:var(--text-3);font-variant-numeric:tabular-nums;height:14px}

.m-row{padding:14px 0;border-bottom:1px solid var(--line)}
.m-row:last-child{border-bottom:0}
.m-top{display:flex;align-items:baseline;justify-content:space-between;gap:10px;margin-bottom:8px}
.m-name{font-size:14.5px;font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.m-val{font-size:12.5px;color:var(--text-3);flex:none;font-variant-numeric:tabular-nums}
.m-row .progress{height:5px}

/* ---------- 设置 / 导入 ---------- */
.settings-group{margin-bottom:18px}
.settings-group .label{font-size:12.5px;font-weight:700;color:var(--text-3);letter-spacing:.5px;margin:0 4px 8px}
.set-row{display:flex;align-items:center;gap:13px;width:100%;padding:15px 16px;border-bottom:1px solid var(--line);transition:background .14s}
.set-row:last-child{border-bottom:0}
.set-row:active{background:var(--card-2)}
.set-ico{width:34px;height:34px;border-radius:10px;display:grid;place-items:center;background:var(--brand-soft);color:var(--brand);flex:none}
.set-ico.red{background:var(--red-soft);color:var(--red)}
.set-ico.amber{background:var(--amber-soft);color:var(--amber)}
.set-main{flex:1;min-width:0}
.set-title{font-size:16px;font-weight:600}
.set-sub{font-size:12px;color:var(--text-3);margin-top:1px}

.field{margin-bottom:16px}
.field>label{display:block;font-size:13px;font-weight:650;color:var(--text-2);margin:0 2px 7px}
.input,.textarea{
  width:100%;border:1.5px solid var(--line);background:var(--card);
  border-radius:13px;padding:12px 14px;font-size:16px;line-height:1.6;
  transition:border-color .16s;
}
.input:focus,.textarea:focus{outline:none;border-color:var(--brand)}
.textarea{min-height:168px;resize:vertical;font-size:14.5px;line-height:1.7;font-family:ui-monospace,SFMono-Regular,Menlo,monospace}
.dropzone{
  display:flex;flex-direction:column;align-items:center;gap:6px;
  padding:22px 16px;border:1.5px dashed var(--line);border-radius:16px;
  background:var(--card-2);color:var(--text-2);text-align:center;margin-bottom:16px;
}
.dropzone:active{border-color:var(--brand);background:var(--brand-soft)}
.dropzone b{font-size:14.5px;font-weight:650;color:var(--text)}
.dropzone span{font-size:12px;color:var(--text-3)}
.import-preview{margin-top:6px}
.preview-line{display:flex;align-items:center;justify-content:space-between;padding:11px 0;border-bottom:1px solid var(--line);font-size:14px}
.preview-line:last-child{border-bottom:0}
.preview-line b{font-variant-numeric:tabular-nums}
.preview-line .ok{color:var(--green)}
.preview-line .warn{color:var(--amber)}
.preview-line .bad{color:var(--red)}
.err-list{margin-top:10px;font-size:12.5px;color:var(--red);line-height:1.7;max-height:150px;overflow:auto}
.sample-q{padding:12px 0;border-bottom:1px solid var(--line);font-size:13.5px;color:var(--text-2);line-height:1.6}
.sample-q:last-child{border-bottom:0}
.sample-q b{color:var(--text);font-weight:650;display:block;margin-bottom:4px}
.sample-q .k{color:var(--brand);font-weight:700}
.import-bar{position:sticky;bottom:calc(var(--safe-b) + 8px);margin-top:18px}

.format-block{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:12.5px;line-height:1.85;
  background:var(--card-2);border:1px solid var(--line);border-radius:12px;padding:14px;white-space:pre-wrap;
  color:var(--text-2);overflow:auto;max-height:280px}

/* ---------- 弹层 ---------- */
.layer{
  position:fixed;inset:0;z-index:60;display:flex;align-items:flex-end;justify-content:center;
  background:rgba(10,15,26,.42);backdrop-filter:blur(3px);-webkit-backdrop-filter:blur(3px);
  animation:fadeIn .22s ease;
}
@keyframes fadeIn{from{opacity:0}to{opacity:1}}
.sheet{
  width:100%;max-width:560px;max-height:88dvh;overflow-y:auto;
  background:var(--card);border-radius:26px 26px 0 0;
  padding:10px 18px calc(18px + var(--safe-b));
  animation:slideUp .3s cubic-bezier(.2,.9,.2,1);
  box-shadow:0 -20px 60px -20px rgba(0,0,0,.35);
}
@keyframes slideUp{from{transform:translateY(40px);opacity:.6}to{transform:none;opacity:1}}
.sheet-handle{width:38px;height:5px;border-radius:99px;background:var(--line);margin:2px auto 12px}
.sheet-head{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:14px}
.sheet-head h3{font-size:18px;font-weight:750}
.sheet-action{
  display:flex;align-items:center;gap:12px;width:100%;padding:16px 2px;
  border-bottom:1px solid var(--line);font-size:16.5px;font-weight:550;
}
.sheet-action:last-child{border-bottom:0}
.sheet-action.danger{color:var(--red)}
.sheet-action .sc{color:var(--text-3);font-size:12.5px;margin-left:auto;font-weight:400}
.sheet-note{font-size:13px;line-height:1.7;color:var(--text-3);margin-top:12px}
.sheet .btn-block{margin-top:16px}

/* Toast */
.toast{
  position:fixed;left:50%;bottom:calc(var(--tab-h) + 26px + var(--safe-b));
  transform:translate(-50%,12px);
  background:rgba(17,24,39,.92);color:#fff;
  font-size:13.5px;font-weight:550;padding:10px 18px;border-radius:99px;
  opacity:0;pointer-events:none;transition:opacity .24s,transform .24s;
  z-index:90;max-width:80vw;text-align:center;
  backdrop-filter:blur(10px);
}
.toast.show{opacity:1;transform:translate(-50%,0)}
body.quiz-mode .toast{bottom:calc(var(--safe-b) + 86px)}

/* ---------- iPad / 宽屏 ---------- */
@media (min-width:560px){
  .stat-grid{grid-template-columns:repeat(4,1fr)}
  .opts{gap:12px}
}
@media (min-width:900px){
  .main{margin-left:100px;padding:34px 32px 48px;max-width:960px}
  .tabbar{
    top:0;left:0;right:auto;bottom:0;width:100px;height:100dvh;
    flex-direction:column;justify-content:flex-start;gap:6px;
    padding:calc(var(--safe-t) + 30px) 12px 20px;
    border-top:0;border-right:1px solid var(--line);
    background:var(--card);
  }
  .tab{flex:0 0 auto;width:100%;padding:13px 0;border-radius:14px;gap:5px}
  .tab.active{background:var(--brand-soft)}
  .tab-label{font-size:11.5px}
  .nav-bar{margin-left:-32px;margin-right:-32px;padding-left:32px;padding-right:32px}
  .quiz-body{padding:26px 32px 36px}
  .quiz-head{padding-left:32px;padding-right:32px}
  .quiz-foot{padding-left:32px;padding-right:32px}
  .quiz-progress{margin-left:32px;margin-right:32px}
  .layer{align-items:center;padding:24px}
  .sheet{border-radius:24px;max-height:82dvh;padding-bottom:20px;box-shadow:var(--shadow-lg)}
  .qgrid{grid-template-columns:repeat(8,1fr)}
  .bank-list{display:grid;grid-template-columns:1fr 1fr;gap:14px}
  .hero{padding:26px}
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion:reduce){
  *{animation:none!important;transition:none!important}
}

/* 滚动条（桌面/iPad 外接键盘场景） */
::-webkit-scrollbar{width:6px;height:6px}
::-webkit-scrollbar-thumb{background:var(--line);border-radius:99px}