:root{
  --bg:#f5f6fa; --card:#fff; --ink:#1c2333; --muted:#7a8194; --line:#e6e8f0;
  --brand:#1a2f4a; --gold:#e8b64c; --ok:#2e9e5b; --bad:#d64541; --warn:#c77d0a;
  --radius:14px; --shadow:0 2px 10px rgba(26,47,74,.08);
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;padding:0;background:var(--bg);color:var(--ink);
  font:15px/1.55 -apple-system,"PingFang SC","Microsoft YaHei",sans-serif}
button{font:inherit;border:none;background:none;cursor:pointer;color:inherit}
input,select,textarea{font:inherit}
.hidden{display:none!important}

/* 布局 */
#app{max-width:760px;margin:0 auto;min-height:100vh;display:flex;flex-direction:column}
.topbar{position:sticky;top:0;z-index:20;background:var(--brand);color:#fff;
  display:flex;align-items:center;justify-content:space-between;padding:10px 14px;padding-top:calc(10px + env(safe-area-inset-top))}
.brand{display:flex;align-items:center;gap:8px}
.brand-logo{width:30px;height:30px;border-radius:8px;background:var(--gold);color:var(--brand);
  display:flex;align-items:center;justify-content:center;font-weight:800;font-size:17px}
.brand-name{font-weight:700;font-size:16px}
.brand-name em{font-style:normal;font-weight:400;font-size:11px;color:#9fb0c8;margin-left:6px}
.top-actions{display:flex;gap:8px}
.badge{background:rgba(255,255,255,.14);border-radius:20px;padding:2px 10px;font-size:12px}
.badge.cd{background:var(--gold);color:var(--brand);font-weight:700;cursor:pointer}
.badge.cd.warn{background:#ff6b5e;color:#fff;animation:pulse 1.6s infinite}
@keyframes pulse{50%{opacity:.55}}
@media(max-width:560px){.brand-name em{display:none}}
.view{flex:1;padding:14px 14px calc(76px + env(safe-area-inset-bottom));}
.tabbar{position:fixed;bottom:0;left:50%;transform:translateX(-50%);width:100%;max-width:760px;z-index:20;
  background:#fff;border-top:1px solid var(--line);display:flex;
  padding-bottom:env(safe-area-inset-bottom)}
.tab{flex:1;padding:7px 0 6px;display:flex;flex-direction:column;align-items:center;gap:1px;
  font-size:10.5px;color:var(--muted)}
.tab span{font-size:19px;line-height:1}
.tab.active{color:var(--brand);font-weight:700}

/* 卡片与通用 */
.card{background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);padding:14px;margin-bottom:12px}
.card h3{margin:0 0 8px;font-size:15px}
.row{display:flex;align-items:center;gap:10px}
.grow{flex:1;min-width:0}
.muted{color:var(--muted);font-size:12.5px}
.big{font-size:22px;font-weight:800}
.btn{display:inline-block;background:#eef1f7;color:var(--ink);border-radius:10px;padding:9px 14px;font-size:14px;text-align:center}
.btn.primary{background:var(--brand);color:#fff}
.btn.gold{background:var(--gold);color:var(--brand);font-weight:700}
.btn.danger{background:#fdecec;color:var(--bad)}
.btn.block{display:block;width:100%}
.btn:disabled{opacity:.45}
.chip{display:inline-block;background:#eef1f7;border-radius:16px;padding:3px 10px;font-size:12px;margin:2px 4px 2px 0}
.chip.on{background:var(--brand);color:#fff}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.grid4{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}
.list-item{display:flex;align-items:center;gap:10px;padding:11px 2px;border-bottom:1px solid var(--line)}
.list-item:last-child{border-bottom:none}
.bar{height:8px;background:#eef1f7;border-radius:6px;overflow:hidden;margin-top:4px}
.bar i{display:block;height:100%;background:var(--brand);border-radius:6px}
.bar i.gold{background:var(--gold)}
.bar i.bad{background:var(--bad)}
.num{font-variant-numeric:tabular-nums}
input[type=text],input[type=password],select,textarea{width:100%;border:1px solid var(--line);border-radius:10px;padding:9px 10px;background:#fff}
textarea{min-height:90px;resize:vertical}
label.f{display:block;margin:10px 0 4px;font-size:13px;color:var(--muted)}

/* 答题 */
.qmeta{display:flex;align-items:center;gap:10px;font-size:13px;color:var(--muted);margin-bottom:8px;flex-wrap:wrap}
.qmeta span,.qmeta b{white-space:nowrap}
.qmeta b{color:var(--ink)}
.qstem{font-size:16px;font-weight:600;line-height:1.65;margin:6px 0 14px;white-space:pre-wrap}
.opt{display:block;width:100%;text-align:left;background:#fff;border:1.5px solid var(--line);
  border-radius:12px;padding:11px 12px;margin-bottom:9px;line-height:1.5}
.opt .key{display:inline-flex;width:22px;height:22px;border-radius:50%;background:#eef1f7;
  align-items:center;justify-content:center;font-weight:700;font-size:13px;margin-right:8px;flex:none}
.opt.sel{border-color:var(--brand);background:#f0f4fa}
.opt.right{border-color:var(--ok);background:#effaf3}
.opt.wrong{border-color:var(--bad);background:#fdf1f0}
.opt.dim{opacity:.55}
.analysis{background:#f6f8fc;border-radius:12px;padding:12px;margin-top:6px;white-space:pre-wrap;line-height:1.6;font-size:14px}
.analysis.good{background:#effaf3}
.verdict{font-weight:800;margin:10px 0 4px}
.verdict.ok{color:var(--ok)} .verdict.bad{color:var(--bad)}
.qfoot{display:flex;gap:8px;margin-top:14px}
.qfoot .btn{flex:1}
.kp-link{color:var(--brand);text-decoration:underline;font-size:13px;margin-right:10px}

/* 答题卡 */
.sheet{display:grid;grid-template-columns:repeat(8,1fr);gap:7px}
.sheet button{height:36px;border-radius:8px;background:#eef1f7;font-size:13px}
.sheet button.done{background:var(--brand);color:#fff}
.sheet button.flag{outline:2px solid var(--gold)}
.timer{font-variant-numeric:tabular-nums;font-weight:700;color:var(--brand)}
.timer.low{color:var(--bad)}

/* 层与弹窗 */
.layer{position:fixed;inset:0;z-index:50;background:var(--bg);overflow-y:auto;
  padding:calc(10px + env(safe-area-inset-top)) 14px calc(20px + env(safe-area-inset-bottom))}
.layer .top{display:flex;align-items:center;justify-content:space-between;margin-bottom:10px}
.layer .top .title{font-weight:800;font-size:16px}
.icon-btn{width:34px;height:34px;border-radius:50%;background:#fff;box-shadow:var(--shadow);
  display:flex;align-items:center;justify-content:center;font-size:16px}
.modal-box{background:#fff;border-radius:16px;padding:18px;max-width:420px;margin:15vh auto 0;box-shadow:0 10px 40px rgba(0,0,0,.2)}
.toast{position:fixed;left:50%;bottom:calc(96px + env(safe-area-inset-bottom));transform:translateX(-50%);
  background:rgba(28,35,51,.92);color:#fff;padding:9px 16px;border-radius:20px;font-size:13px;z-index:99;max-width:86vw}

/* 知识点 */
.kp-head{display:flex;align-items:flex-start;gap:8px}
.kp-title{font-size:19px;font-weight:800}
.stars{color:var(--gold);font-size:13px;letter-spacing:1px}
.sec{margin-top:14px}
.sec>h4{margin:0 0 6px;font-size:14px;color:var(--brand)}
.sec .body{background:#fff;border-radius:12px;padding:12px;box-shadow:var(--shadow)}
.kp-sum{font-size:15px;font-weight:600;background:#fdf6e6;border-left:4px solid var(--gold);
  padding:10px 12px;border-radius:0 10px 10px 0}
table.cmp{width:100%;border-collapse:collapse;font-size:13.5px}
table.cmp td,table.cmp th{border:1px solid var(--line);padding:7px 8px;text-align:left;vertical-align:top}
table.cmp th{background:#f0f4fa}
.hl{background:#fff3c4;border-radius:3px;padding:0 2px}

/* 报告 */
.stat4{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;text-align:center}
.stat4 .card{margin:0;padding:10px 4px}
.stat4 .v{font-size:17px;font-weight:800}
.stat4 .k{font-size:11px;color:var(--muted)}
.pat{background:#fff7ef;border-left:4px solid var(--warn);border-radius:0 10px 10px 0;padding:9px 12px;margin:8px 0;font-size:13.5px}
.pat.bad{background:#fdf1f0;border-color:var(--bad)}

/* AI */
.ai-msg{background:#fff;border-radius:12px;padding:12px;margin-bottom:10px;white-space:pre-wrap;line-height:1.65;box-shadow:var(--shadow);font-size:14.5px}
.ai-msg.user{background:#eef4ff}
.ai-msg .cursor{display:inline-block;width:8px;height:15px;background:var(--brand);vertical-align:-2px;animation:bl 1s infinite}
@keyframes bl{50%{opacity:0}}

@media(min-width:900px){ .view{padding-left:calc((100% - 720px)/2);padding-right:calc((100% - 720px)/2)} }