:root{
  --bg:#f4f6fb;
  --card:#ffffff;
  --line:#e5e9f2;
  --line-soft:#eef1f7;
  --text:#1a2233;
  --muted:#6c7a90;
  --brand:#4f46e5;
  --brand-d:#4338ca;
  --brand-soft:#eef0ff;
  --ok:#0f9d58;
  --ok-soft:#e8f7ef;
  --warn:#c2740a;
  --warn-soft:#fdf3e2;
  --danger:#dc2626;
  --danger-soft:#fdecec;
  --shadow:0 1px 2px rgba(20,30,60,.05),0 8px 24px rgba(20,30,60,.06);
  --radius:14px;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  background:var(--bg);color:var(--text);
  font:14px/1.65 system-ui,-apple-system,"Segoe UI","Microsoft YaHei","PingFang SC",sans-serif;
  -webkit-font-smoothing:antialiased;
}
button,input,select,textarea{font-family:inherit;font-size:inherit;color:inherit}
h1,h2,h3,h4,p{margin:0}
.hidden{display:none !important}

/* ---------- 启动 ---------- */
.boot{position:fixed;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:14px;color:var(--muted)}
.spinner{width:26px;height:26px;border:3px solid var(--line);border-top-color:var(--brand);border-radius:50%;animation:spin .8s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}

/* ---------- 登录 ---------- */
.auth{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:24px 16px;
  background:radial-gradient(1200px 500px at 50% -10%,#e8ebff 0%,var(--bg) 60%)}
.auth-card{width:100%;max-width:420px;background:var(--card);border:1px solid var(--line);border-radius:20px;
  box-shadow:var(--shadow);padding:28px 26px 24px}
.brand-lg{display:flex;gap:14px;align-items:center;margin-bottom:22px}
.brand-lg h1{font-size:19px;letter-spacing:.2px}
.brand-lg p{font-size:12.5px;color:var(--muted);margin-top:2px}
.logo{width:44px;height:44px;border-radius:14px;display:flex;align-items:center;justify-content:center;
  background:linear-gradient(135deg,#6366f1,#4f46e5);color:#fff;font-weight:700;font-size:20px;flex:0 0 auto}
.logo.sm{width:30px;height:30px;border-radius:10px;font-size:15px}
.tabs{display:flex;gap:6px;background:#f2f4fa;padding:4px;border-radius:12px;margin-bottom:18px}
.tab{flex:1;border:0;background:transparent;padding:8px 10px;border-radius:9px;color:var(--muted);cursor:pointer;font-weight:500}
.tab.active{background:#fff;color:var(--brand);box-shadow:0 1px 3px rgba(20,30,60,.08)}
.field{display:block;margin-bottom:14px}
.field>span{display:block;font-size:12.5px;color:var(--muted);margin-bottom:6px}
.input{width:100%;border:1px solid var(--line);border-radius:11px;padding:11px 12px;background:#fff;outline:none;transition:.15s}
.input:focus{border-color:#b9b8f5;box-shadow:0 0 0 3px var(--brand-soft)}
.input::placeholder{color:#a9b4c4}
textarea.input{resize:vertical;min-height:84px;line-height:1.6}
.code-row{display:flex;gap:8px}
.code-row .input{flex:1}
.field-err{display:block;color:var(--danger);font-size:12px;margin-top:6px;font-style:normal}
.auth-tip{font-size:12px;color:var(--muted);margin-top:14px;line-height:1.6}
.or-line{display:flex;align-items:center;gap:10px;margin:16px 0 12px;color:#a9b4c4;font-size:11.5px}
.or-line::before,.or-line::after{content:"";flex:1;height:1px;background:var(--line)}
.oauth-row{display:flex;gap:8px}
.oauth-row .btn{flex:1;font-size:12.5px;padding:9px 8px}
.wx-dot{width:8px;height:8px;border-radius:50%;background:#22c55e;display:inline-block}
.auth-err{margin-top:12px;color:var(--danger);font-size:13px;background:var(--danger-soft);padding:9px 11px;border-radius:10px}
.btn{border:1px solid transparent;border-radius:11px;padding:9px 14px;cursor:pointer;background:#fff;
  transition:.15s;white-space:nowrap;font-weight:500;display:inline-flex;align-items:center;gap:6px;justify-content:center}
.btn:disabled{opacity:.55;cursor:not-allowed}
.btn-primary{background:var(--brand);color:#fff}
.btn-primary:hover:not(:disabled){background:var(--brand-d)}
.btn-ghost{border-color:var(--line);color:#3b4759;background:#fff}
.btn-ghost:hover:not(:disabled){border-color:#c9d2e2;background:#fafbff}
.btn-soft{background:var(--brand-soft);color:var(--brand);border-color:transparent}
.btn-soft:hover:not(:disabled){background:#e4e6ff}
.btn-danger-ghost{color:var(--danger);border-color:#f4cfcf;background:#fff}
.btn-danger-ghost:hover:not(:disabled){background:var(--danger-soft)}
.btn-block{width:100%;padding:11px 14px}
.btn-sm{padding:5px 10px;border-radius:9px;font-size:12.5px}

/* ---------- 布局 ---------- */
.topbar{position:sticky;top:0;z-index:30;background:rgba(255,255,255,.92);backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line)}
.topbar-inner{max-width:1180px;margin:0 auto;padding:0 16px;height:58px;display:flex;align-items:center;gap:16px}
.brand{display:flex;align-items:center;gap:9px;font-size:14.5px;flex:0 0 auto}
.nav{display:flex;gap:2px;flex:1;overflow-x:auto;scrollbar-width:none}
.nav::-webkit-scrollbar{display:none}
.nav-btn{border:0;background:transparent;padding:8px 14px;border-radius:10px;color:var(--muted);cursor:pointer;font-weight:500}
.nav-btn:hover{background:#f4f6fb;color:#33415c}
.nav-btn.active{background:var(--brand-soft);color:var(--brand)}
.user{display:flex;align-items:center;gap:8px;flex:0 0 auto}
.avatar{width:32px;height:32px;border-radius:50%;background:linear-gradient(135deg,#818cf8,#4f46e5);color:#fff;
  display:flex;align-items:center;justify-content:center;font-weight:600;font-size:13px;cursor:pointer}
.user-name{font-size:13px;color:#33415c;cursor:pointer;max-width:120px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.main{max-width:1180px;margin:0 auto;padding:22px 16px 60px}
.view{animation:fade .18s ease-out}
@keyframes fade{from{opacity:0;transform:translateY(3px)}to{opacity:1;transform:none}}

/* ---------- 通用块 ---------- */
.page-head{display:flex;align-items:flex-end;justify-content:space-between;gap:14px;margin-bottom:16px;flex-wrap:wrap}
.page-head h2{font-size:19px}
.page-head p{font-size:12.5px;color:var(--muted);margin-top:3px}
.head-actions{display:flex;gap:8px;flex-wrap:wrap}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}
.empty{padding:46px 20px;text-align:center;color:var(--muted);font-size:13px}
.empty b{display:block;color:#3b4759;font-size:14px;margin-bottom:6px}
.loading{padding:40px;text-align:center;color:var(--muted);font-size:13px}
.chip{display:inline-flex;align-items:center;gap:4px;padding:2px 8px;border-radius:8px;font-size:11.5px;
  background:#f1f4fa;color:#4a5a72;white-space:nowrap}
.chip.brand{background:var(--brand-soft);color:var(--brand)}
.chip.ok{background:var(--ok-soft);color:var(--ok)}
.chip.warn{background:var(--warn-soft);color:var(--warn)}
.chip.danger{background:var(--danger-soft);color:var(--danger)}
.chip.mono{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;letter-spacing:1.5px;font-weight:600}
.divider{height:1px;background:var(--line-soft);margin:14px 0}

/* ---------- 题库 ---------- */
.toolbar{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:14px}
.toolbar .input,.toolbar .select{width:auto;min-width:130px}
.select{border:1px solid var(--line);border-radius:11px;padding:9px 10px;background:#fff;outline:none}
.q-list{display:flex;flex-direction:column;gap:10px}
.q-card{padding:15px 17px}
.q-head{display:flex;align-items:center;gap:8px;margin-bottom:8px;flex-wrap:wrap}
.q-stem{font-size:14.5px;line-height:1.7;color:#1d2637;white-space:pre-wrap;word-break:break-word}
.q-opts{display:flex;flex-direction:column;gap:3px;margin:9px 0 0;padding:0;list-style:none}
.q-opts li{font-size:13.5px;color:#41506a;display:flex;gap:7px}
.q-opts .ol{color:var(--muted);font-weight:600;flex:0 0 auto}
.q-foot{display:flex;gap:14px;align-items:center;margin-top:10px;flex-wrap:wrap;font-size:12.5px;color:var(--muted)}
.q-foot b{color:var(--ok);font-weight:600}
.q-acts{margin-left:auto;display:flex;gap:6px}
.q-analysis{font-size:12.5px;color:#5a6a83;background:#f8fafd;border-left:2px solid #dfe5f0;
  padding:8px 11px;border-radius:0 8px 8px 0;margin-top:10px;white-space:pre-wrap}

/* ---------- 试卷 ---------- */
.paper-list{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:12px}
.paper-card{padding:16px 17px;display:flex;flex-direction:column;gap:10px}
.paper-card h3{font-size:15px;line-height:1.5}
.paper-meta{display:flex;gap:8px;flex-wrap:wrap;font-size:12px;color:var(--muted)}
.code-box{display:flex;align-items:center;gap:8px;flex-wrap:wrap;background:#f7f9fd;border:1px dashed #d7dfec;border-radius:10px;padding:8px 11px}
.code-box .chip.mono{font-size:14px;background:#fff;border:1px solid var(--line);padding:3px 9px}
.paper-acts{display:flex;gap:6px;flex-wrap:wrap;margin-top:2px}
.chk-row{display:flex;gap:16px;flex-wrap:wrap;padding-top:7px}
.chk{display:inline-flex;align-items:center;gap:6px;font-size:13px;color:#3b4759;cursor:pointer;line-height:1.4}
.chk input{width:15px;height:15px;margin:0;accent-color:var(--brand);cursor:pointer}
.chk-note{font-size:12px;color:var(--muted);margin-top:8px;line-height:1.6}

/* ---------- 表单 ---------- */
.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.form-grid .span2{grid-column:1/-1}
.form-grid h4{grid-column:1/-1;font-size:13px;color:var(--muted);font-weight:600;margin-top:4px}
.opt-row{display:flex;gap:8px;align-items:center;margin-bottom:8px}
.opt-row .ol{width:22px;text-align:center;font-weight:600;color:var(--muted)}
.opt-row .input{flex:1}

/* ---------- 考试 ---------- */
.join-box{max-width:520px;margin:40px auto;padding:28px;text-align:center}
.join-box h2{font-size:18px;margin-bottom:6px}
.join-box p{color:var(--muted);font-size:13px;margin-bottom:18px}
.join-row{display:flex;gap:9px}
.join-row .input{text-align:center;letter-spacing:6px;font-size:18px;font-weight:600;text-transform:uppercase}
.exam-shell{display:grid;grid-template-columns:1fr 232px;gap:16px;align-items:start}
.exam-head{position:sticky;top:58px;z-index:20;background:rgba(255,255,255,.96);backdrop-filter:blur(8px);
  border:1px solid var(--line);border-radius:var(--radius);padding:12px 16px;margin-bottom:14px;
  display:flex;align-items:center;gap:14px;flex-wrap:wrap;box-shadow:var(--shadow)}
.exam-head h3{font-size:15px;flex:1;min-width:150px}
.timer{font-variant-numeric:tabular-nums;font-weight:700;font-size:16px;color:var(--brand);
  background:var(--brand-soft);padding:5px 12px;border-radius:10px}
.timer.hot{color:#fff;background:var(--danger)}
.exam-q{padding:16px 18px;margin-bottom:10px;scroll-margin-top:150px}
.exam-q .q-idx{font-weight:700;color:var(--brand);margin-right:6px}
.opt{display:flex;gap:10px;align-items:flex-start;border:1px solid var(--line);border-radius:11px;
  padding:10px 13px;margin-top:8px;cursor:pointer;transition:.13s;background:#fff}
.opt:hover{border-color:#c6cbf0;background:#fbfcff}
.opt.sel{border-color:var(--brand);background:var(--brand-soft)}
.opt .ok-box{width:20px;height:20px;border-radius:50%;border:1.5px solid #c3ccda;flex:0 0 auto;
  display:flex;align-items:center;justify-content:center;font-size:11.5px;font-weight:700;color:var(--muted);margin-top:1px}
.opt.sel .ok-box{background:var(--brand);border-color:var(--brand);color:#fff}
.opt.multi .ok-box{border-radius:6px}
.answer-card{position:sticky;top:120px;padding:14px}
.answer-card h4{font-size:13px;margin-bottom:10px;color:#3b4759}
.grid-nums{display:grid;grid-template-columns:repeat(5,1fr);gap:7px}
.num{aspect-ratio:1;border:1px solid var(--line);border-radius:9px;background:#fff;cursor:pointer;
  font-size:12.5px;color:#5a6a83;display:flex;align-items:center;justify-content:center;padding:0}
.num.done{background:var(--brand-soft);border-color:#c7c9f7;color:var(--brand);font-weight:600}
.result-hero{padding:26px;text-align:center;margin-bottom:16px}
.score-big{font-size:44px;font-weight:800;line-height:1.1;color:var(--brand)}
.score-big small{font-size:15px;font-weight:600;color:var(--muted);margin-left:3px}
.result-hero .meta{display:flex;gap:18px;justify-content:center;flex-wrap:wrap;margin-top:12px;font-size:12.5px;color:var(--muted)}
.review-q{padding:14px 17px;margin-bottom:10px}
.review-head{display:flex;align-items:center;gap:8px;margin-bottom:7px;flex-wrap:wrap}
.ans-line{font-size:12.5px;margin-top:7px;display:flex;gap:14px;flex-wrap:wrap}
.ans-line .y{color:var(--danger)}
.ans-line .c{color:var(--ok);font-weight:600}

/* ---------- 成绩 ---------- */
.sec{margin-bottom:24px}
.sec-head{display:flex;align-items:center;gap:10px;margin-bottom:10px}
.sec-head h3{font-size:15px}
.sec-head .count{font-size:12px;color:var(--muted)}
.table{width:100%;border-collapse:collapse;font-size:13px}
.table th{text-align:left;font-weight:500;color:var(--muted);font-size:12px;padding:9px 12px;border-bottom:1px solid var(--line);white-space:nowrap}
.table td{padding:10px 12px;border-bottom:1px solid var(--line-soft);vertical-align:middle}
.table tr:last-child td{border-bottom:0}
.table tbody tr:hover{background:#fafbff}
.table .num-cell{font-variant-numeric:tabular-nums;font-weight:600}
.stat-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(104px,1fr));gap:10px;margin-bottom:16px}
.stat{background:#f8fafd;border:1px solid var(--line-soft);border-radius:12px;padding:11px 13px}
.stat span{display:block;font-size:11.5px;color:var(--muted)}
.stat b{font-size:19px;font-variant-numeric:tabular-nums}
.dist{display:flex;flex-direction:column;gap:7px;margin-bottom:16px}
.dist-row{display:flex;align-items:center;gap:9px;font-size:12px;color:var(--muted)}
.dist-row .lab{width:64px;flex:0 0 auto}
.dist-bar{flex:1;height:9px;background:#eef1f8;border-radius:6px;overflow:hidden}
.dist-bar i{display:block;height:100%;background:linear-gradient(90deg,#818cf8,#4f46e5);border-radius:6px}
.dist-row .cnt{width:52px;text-align:right;flex:0 0 auto;color:#3b4759;font-variant-numeric:tabular-nums}

/* ---------- 弹窗 & toast ---------- */
.modal-mask{position:fixed;inset:0;background:rgba(22,30,48,.42);display:flex;align-items:center;
  justify-content:center;padding:18px;z-index:60;animation:fade .14s}
.modal{background:#fff;border-radius:18px;width:100%;max-width:520px;max-height:88vh;display:flex;
  flex-direction:column;box-shadow:0 24px 60px rgba(15,23,42,.24)}
.modal.wide{max-width:820px}
.modal-head{display:flex;align-items:center;gap:10px;padding:16px 18px 12px;border-bottom:1px solid var(--line-soft)}
.modal-head h3{font-size:15.5px;flex:1}
.modal-x{border:0;background:transparent;font-size:22px;line-height:1;color:#93a0b4;cursor:pointer;padding:0 2px}
.modal-body{padding:16px 18px;overflow:auto}
.modal-foot{display:flex;gap:8px;justify-content:flex-end;padding:12px 18px 16px;border-top:1px solid var(--line-soft)}
.modal-foot .left{margin-right:auto}
.toast-root{position:fixed;left:50%;bottom:28px;transform:translateX(-50%);z-index:80;display:flex;
  flex-direction:column;gap:8px;align-items:center;pointer-events:none}
.toast{background:#1f2937;color:#fff;padding:9px 16px;border-radius:11px;font-size:13px;
  box-shadow:0 8px 24px rgba(15,23,42,.2);animation:rise .2s ease-out;max-width:86vw}
.toast.ok{background:#0f9d58}
.toast.err{background:#dc2626}
@keyframes rise{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
.hint{font-size:12.5px;color:var(--muted);line-height:1.7}
.hint code{background:#f2f4fa;padding:1px 5px;border-radius:5px;font-size:12px}
.mono{font-family:ui-monospace,SFMono-Regular,Menlo,monospace}

/* ---------- 填空 / 简答 ---------- */
.fill-row{display:flex;align-items:center;gap:10px;margin-bottom:8px}
.fill-no{flex:0 0 auto;font-size:12px;color:var(--muted);min-width:54px}
.fill-row .input{flex:1;min-width:0}
.ta-short{min-height:118px;width:100%;resize:vertical;line-height:1.75;font-size:13.5px}
.ans-block{margin-top:9px;background:#f7f9fd;border:1px solid var(--line);border-radius:10px;padding:9px 11px}
.ans-block .lab{display:block;font-size:12px;color:var(--muted);margin-bottom:4px}
.ans-block .txt{font-size:13.5px;color:#2a3444;line-height:1.8;white-space:pre-wrap;word-break:break-word}
.ans-block.ref{background:#f2fbf6;border-color:#cbe8d8}
.muted{color:var(--muted);font-style:normal}
.grade-row{display:flex;align-items:center;gap:8px;margin-top:8px;flex-wrap:wrap}
.grade-row .input{width:96px}

@media (max-width:900px){
  .exam-shell{grid-template-columns:1fr}
  .answer-card{position:static;order:-1}
  .grid-nums{grid-template-columns:repeat(10,1fr)}
  .num{font-size:11.5px}
}
@media (max-width:640px){
  .topbar-inner{height:auto;padding:9px 14px;flex-wrap:wrap;gap:10px}
  .brand b{display:none}
  .main{padding:16px 12px 50px}
  .form-grid{grid-template-columns:1fr}
  .page-head h2{font-size:17px}
  .grid-nums{grid-template-columns:repeat(8,1fr)}
  .exam-head{top:0}
}

/* 账号管理 */
.acc-acts{display:flex;gap:6px;flex-wrap:wrap}
.pwd-box{border-top:1px solid #eef1f7;margin-top:14px;padding-top:4px}
.imp-sample{background:#f7f9fd;border:1px dashed #d7dfec;border-radius:9px;padding:10px 12px;
  font-size:12px;line-height:1.85;color:#5a6b84;margin:0 0 10px;white-space:pre-wrap;
  font-family:ui-monospace,SFMono-Regular,Menlo,monospace}
.imp-ta{width:100%;min-height:168px;resize:vertical;font-size:12.5px;line-height:1.95;
  font-family:ui-monospace,SFMono-Regular,Menlo,monospace;white-space:pre;overflow:auto}
.imp-info{font-size:12.5px;color:#5a6b84;margin-top:10px}
.imp-info b{color:var(--brand)}
.imp-skip{max-height:260px;overflow:auto;font-size:12.5px;line-height:2;color:#8a4b4b;
  background:#fdf6f6;border-radius:9px;padding:10px 12px}

/* 错题本 */
.chk-inline{display:inline-flex;align-items:center;gap:6px;font-size:12.5px;color:#5a6b84;
  background:#fff;border:1px solid var(--line);border-radius:11px;padding:0 12px;height:38px;white-space:nowrap}
.chk-inline input{width:14px;height:14px;accent-color:var(--brand)}
.mis-card{margin-bottom:12px;transition:opacity .18s ease,transform .18s ease}
.mis-card.mis-out{opacity:0;transform:translateY(-6px)}
.mis-card.mastered{background:#fbfcfe;border-color:#e3e9f4}
.mis-head{display:flex;align-items:center;gap:6px;flex-wrap:wrap;margin-bottom:9px}
.mis-meta{font-size:11.5px;color:var(--muted);margin-left:auto}
.mis-opts{margin-top:10px;display:flex;flex-direction:column;gap:7px}
.mis-opt{display:flex;gap:10px;align-items:flex-start;border:1px solid var(--line);border-radius:11px;
  padding:9px 12px;background:#fff;font-size:13.5px;color:#2a3444;line-height:1.6}
.mis-opt .ok-box{width:20px;height:20px;border-radius:50%;border:1.5px solid #c3ccda;flex:0 0 auto;
  display:flex;align-items:center;justify-content:center;font-size:11.5px;color:#6b7a90;background:#fff}
.mis-opt-t{flex:1;word-break:break-word}
.mis-opt.ok{border-color:#9fd9b9;background:#f2fbf6}
.mis-opt.ok .ok-box{background:var(--ok);border-color:var(--ok);color:#fff}
.mis-opt.bad{border-color:#f3c9c9;background:#fdf3f3}
.mis-opt.bad .ok-box{background:var(--danger);border-color:var(--danger);color:#fff}
.mis-opt.sel{border-color:var(--brand);background:var(--brand-soft)}
.mis-opt.sel .ok-box{background:var(--brand);border-color:var(--brand);color:#fff}
.mis-tag{font-size:11px;font-style:normal;padding:1px 7px;border-radius:7px;flex:0 0 auto}
.mis-tag.c{background:var(--ok-soft);color:var(--ok)}
.mis-tag.y{background:var(--danger-soft);color:var(--danger)}
.mis-fills{margin-top:10px;display:flex;flex-direction:column;gap:6px}
.mis-fill{display:flex;gap:10px;align-items:baseline;flex-wrap:wrap;font-size:13px;
  border:1px solid var(--line);border-radius:10px;padding:8px 11px;background:#fff}
.mis-fill.ok{border-color:#9fd9b9;background:#f2fbf6}
.mis-fill-no{font-size:11.5px;color:var(--muted);flex:0 0 auto}
.mis-fill-y{color:var(--danger)}
.mis-fill.ok .mis-fill-y{color:var(--ok)}
.mis-fill-c{color:#2a3444;font-size:12.5px;margin-left:auto}
.mis-lock{margin-top:9px;font-size:12.5px;color:#8a6d3b;background:#fdf8ec;border:1px solid #f0e0bd;
  border-radius:9px;padding:8px 11px;line-height:1.7}
.mis-acts{display:flex;gap:8px;margin-top:12px;flex-wrap:wrap;align-items:center}
.mis-del{flex:0 0 auto}
.pra-stem{font-size:15px;line-height:1.75;color:#1d2637;margin-bottom:12px;white-space:pre-wrap}
.pra-foot{display:flex;gap:10px;align-items:center;margin-top:12px;flex-wrap:wrap}
.pra-result{margin-top:12px;font-size:13.5px;padding:9px 12px;border-radius:10px}
.pra-result.ok{background:var(--ok-soft);color:var(--ok)}
.pra-result.bad{background:var(--danger-soft);color:var(--danger)}

/* ---------- 错题本：错题本 / 已掌握 切换 ---------- */
.mis-seg{display:inline-flex;background:#eef1f8;border-radius:11px;padding:3px;gap:2px;height:38px;align-items:center}
.mis-seg button{border:0;background:transparent;border-radius:9px;padding:0 13px;height:32px;
  font:inherit;font-size:12.5px;color:#5a6b84;cursor:pointer;display:inline-flex;align-items:center;gap:5px;white-space:nowrap}
.mis-seg button b{font-size:11.5px;font-variant-numeric:tabular-nums;opacity:.7;font-weight:600}
.mis-seg button:hover{color:#33415a}
.mis-seg button.on{background:#fff;color:var(--brand);font-weight:600;box-shadow:0 1px 3px rgba(16,32,64,.1)}
.mis-seg button.on b{opacity:1;color:var(--brand)}
.stat-link{cursor:pointer;transition:border-color .15s ease,background .15s ease}
.stat-link:hover{border-color:#c9d4e8;background:#f3f6fc}
.stat-link.on{border-color:var(--brand);background:var(--brand-soft)}
.stat-link.on span{color:var(--brand)}

/* 批量导入（题库 / 账号）：文件上传 + 预览 */
.imp-tabs{display:flex;gap:18px;border-bottom:1px solid var(--line);margin:0 0 14px}
.imp-tab{border:0;background:transparent;padding:9px 2px;font-size:13.5px;color:var(--muted);
  cursor:pointer;border-bottom:2px solid transparent;margin-bottom:-1px;transition:.15s}
.imp-tab:hover{color:var(--text)}
.imp-tab.active{color:var(--brand);border-bottom-color:var(--brand);font-weight:600}
.imp-drop{border:1.5px dashed #cfd9ea;border-radius:12px;padding:26px 18px;text-align:center;
  background:#fbfcff;cursor:pointer;transition:.15s}
.imp-drop:hover,.imp-drop.over{border-color:var(--brand);background:#f4f8ff}
.imp-drop b{display:block;font-size:14px;color:#2a3b55;margin-bottom:7px}
.imp-drop span{font-size:12.5px;color:var(--muted);line-height:1.75}
.imp-file{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-top:10px;font-size:13px;color:#3b4759}
.imp-preview{margin-top:12px}
.imp-stat{font-size:13px;color:#3b4759}
.imp-stat b{color:var(--brand);font-size:15px}
.imp-bad{color:var(--danger)}
.imp-warn{color:var(--warn)}
.imp-table-wrap{max-height:250px;overflow:auto;border:1px solid var(--line);border-radius:10px;margin-top:8px}
.imp-table th{position:sticky;top:0;background:#f7f9fd;z-index:1}
.imp-table td{max-width:280px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}