:root{
  --bg:#f4f6f9; --panel:#ffffff; --ink:#1f2933; --muted:#6b7785;
  --line:#e3e8ef; --accent:#2B6CB0; --ok:#2f855a; --bad:#c53030; --shadow:0 2px 10px rgba(31,41,51,.07);
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{font-family:-apple-system,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;
  background:var(--bg); color:var(--ink); line-height:1.6; -webkit-font-smoothing:antialiased;}
.hidden{display:none !important}

/* gate */
.gate{position:fixed;inset:0;display:flex;align-items:center;justify-content:center;
  background:linear-gradient(135deg,#1f3a5f,#2B6CB0);z-index:50;}
.gate-card{background:#fff;border-radius:18px;padding:38px 34px;width:min(92vw,420px);text-align:center;box-shadow:0 20px 60px rgba(0,0,0,.25);}
.gate-logo{color:var(--accent);font-weight:700;letter-spacing:1px;font-size:13px;text-transform:uppercase;}
.gate-card h1{font-size:22px;margin:8px 0 4px;}
.gate-sub{color:var(--muted);font-size:14px;margin-bottom:18px;}
.gate input{width:100%;padding:12px 14px;border:1px solid var(--line);border-radius:10px;font-size:15px;margin-bottom:14px;}
.gate button{width:100%;padding:12px;border:none;border-radius:10px;background:var(--accent);color:#fff;font-size:15px;cursor:pointer;}
.gate-note{color:var(--muted);font-size:12px;margin-top:14px;}

/* topbar */
.topbar{display:flex;justify-content:space-between;align-items:center;padding:12px 18px;
  background:var(--panel);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20;box-shadow:var(--shadow);}
.topbar-left{display:flex;align-items:center;gap:12px;}
.topbar-right{display:flex;align-items:center;gap:10px;}
#brand{font-weight:700;font-size:16px;}
#hello{color:var(--muted);font-size:14px;}
.icon-btn,.ghost-btn{background:none;border:1px solid var(--line);border-radius:8px;padding:7px 12px;cursor:pointer;font-size:14px;color:var(--ink);}
.ghost-btn:hover,.icon-btn:hover{background:#eef2f7;}

.view{max-width:1080px;margin:0 auto;padding:22px 18px 80px;}

/* home */
.home-hero{background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:22px;margin-bottom:20px;box-shadow:var(--shadow);}
.home-hero h2{margin:0 0 6px;font-size:20px;}
.home-hero p{margin:0;color:var(--muted);font-size:14px;}
.stat-row{display:flex;gap:14px;margin-top:16px;flex-wrap:wrap;}
.stat-pill{background:#eef4fb;border-radius:12px;padding:10px 16px;flex:1;min-width:120px;}
.stat-pill b{display:block;font-size:22px;color:var(--accent);}
.stat-pill span{font-size:12px;color:var(--muted);}

.topic-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:16px;}
.topic-card{background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:18px;cursor:pointer;
  border-top:4px solid var(--accent);box-shadow:var(--shadow);transition:transform .12s;}
.topic-card:hover{transform:translateY(-3px);}
.topic-card h3{margin:0 0 4px;font-size:17px;}
.topic-card .cnt{color:var(--muted);font-size:13px;}
.topic-card .bar{height:6px;border-radius:6px;background:#eef2f7;margin-top:12px;overflow:hidden;}
.topic-card .bar>i{display:block;height:100%;background:var(--accent);}

/* exercise list */
.section-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:14px;}
.section-head h2{margin:0;font-size:20px;}
.ex-list{display:flex;flex-direction:column;gap:12px;}
.ex-card{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:14px 16px;cursor:pointer;
  display:flex;justify-content:space-between;align-items:center;box-shadow:var(--shadow);}
.ex-card:hover{background:#f8fafc;}
.ex-card .t{font-weight:600;}
.ex-card .meta{color:var(--muted);font-size:13px;margin-top:2px;}
.ex-card .badge{font-size:12px;padding:3px 9px;border-radius:20px;background:#eef4fb;color:var(--accent);white-space:nowrap;}
.audio-dot{color:#999;font-size:12px;}

/* exercise player */
.ex-head{display:flex;justify-content:space-between;align-items:flex-start;gap:12px;margin-bottom:12px;}
.ex-head h2{margin:0;font-size:22px;}
.ex-head .src{color:var(--muted);font-size:13px;margin-top:2px;}
.q-imgs{display:flex;flex-direction:column;gap:12px;align-items:center;background:#fff;border:1px solid var(--line);border-radius:12px;padding:14px;box-shadow:var(--shadow);}
.q-imgs img{max-width:100%;height:auto;border-radius:6px;cursor:zoom-in;}
.audio-wrap{margin:16px 0;background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:14px;box-shadow:var(--shadow);}
.audio-wrap audio{width:100%;}
.audio-wrap .na{color:var(--bad);font-size:14px;}

.answer-box{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:16px;box-shadow:var(--shadow);margin-bottom:16px;}
.answer-box h3{margin:0 0 8px;font-size:16px;}
.answer-box p.hint{color:var(--muted);font-size:13px;margin:0 0 10px;}
.answer-box textarea{width:100%;min-height:140px;padding:12px;border:1px solid var(--line);border-radius:10px;font-size:15px;font-family:inherit;resize:vertical;}
.btn-row{display:flex;gap:10px;margin-top:12px;flex-wrap:wrap;}
.primary-btn{background:var(--accent);color:#fff;border:none;border-radius:10px;padding:11px 20px;font-size:15px;cursor:pointer;}
.primary-btn:disabled{opacity:.5;cursor:default;}
.secondary-btn{background:#fff;border:1px solid var(--line);border-radius:10px;padding:11px 18px;cursor:pointer;font-size:15px;}

/* results */
.result{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:16px;box-shadow:var(--shadow);margin-bottom:16px;}
.result .score{font-size:18px;font-weight:700;margin-bottom:10px;}
.result .score.ok{color:var(--ok);} .result .score.bad{color:var(--bad);}
.ak-table{width:100%;border-collapse:collapse;font-size:14px;margin-top:6px;}
.ak-table th,.ak-table td{border:1px solid var(--line);padding:6px 8px;text-align:left;vertical-align:top;}
.ak-table th{background:#f1f5f9;}
.ak-table .r-ok{color:var(--ok);font-weight:700;}
.ak-table .r-bad{color:var(--bad);font-weight:700;}
.ak-images{display:flex;flex-direction:column;gap:10px;align-items:center;margin-top:10px;}
.ak-images img{max-width:100%;height:auto;border:1px solid var(--line);border-radius:6px;}
details{margin-top:10px;background:#f8fafc;border:1px solid var(--line);border-radius:10px;padding:10px 12px;}
summary{cursor:pointer;font-weight:600;font-size:14px;}
.ts-text{white-space:pre-wrap;font-size:13px;color:#374151;margin-top:8px;max-height:420px;overflow:auto;}
.note{color:var(--muted);font-size:13px;font-style:italic;margin:6px 0;}

/* modal */
.modal{position:fixed;inset:0;background:rgba(15,23,42,.55);display:flex;align-items:center;justify-content:center;z-index:60;padding:18px;}
.modal-card{background:#fff;border-radius:16px;padding:24px;width:min(94vw,560px);max-height:88vh;overflow:auto;position:relative;box-shadow:0 20px 60px rgba(0,0,0,.3);}
.modal-card.wide{width:min(96vw,820px);}
.modal-card h2{margin:0 0 14px;font-size:19px;}
.modal-close{position:absolute;top:12px;right:14px;border:none;background:none;font-size:24px;cursor:pointer;color:var(--muted);}
.vocab-body{display:flex;flex-direction:column;gap:8px;}
.vocab-item{border:1px solid var(--line);border-radius:10px;padding:10px 12px;}
.vocab-item b{color:var(--accent);}
.vocab-item .def{color:#374151;font-size:14px;}
.vocab-item .eg{color:var(--muted);font-size:13px;margin-top:3px;}
#statsBody table{width:100%;border-collapse:collapse;font-size:14px;}
#statsBody th,#statsBody td{border:1px solid var(--line);padding:6px 8px;}

@media(max-width:560px){
  .view{padding:16px 12px 70px;}
  .topic-grid{grid-template-columns:1fr 1fr;}
}

/* ---------- 文本题型（求职等讲义题） ---------- */
.q-text{background:#fff;border:1px solid var(--line);border-radius:12px;padding:18px 20px;box-shadow:var(--shadow);line-height:1.75;}
.q-text p{margin:0 0 6px;font-size:15px;color:var(--ink);white-space:pre-wrap;}
.q-text p:last-child{margin-bottom:0;}
.ans-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(190px,1fr));gap:10px;}
.ans-cell{display:flex;align-items:center;gap:8px;border:1px solid var(--line);border-radius:9px;padding:6px 10px;background:#fbfdff;}
.ans-cell label{min-width:22px;text-align:center;font-weight:600;color:var(--accent);font-size:14px;}
.ans-cell input{flex:1;border:none;background:transparent;font-size:15px;padding:6px 2px;outline:none;width:100%;}
table.ans-table{width:100%;border-collapse:collapse;font-size:14px;margin-top:8px;}
table.ans-table th,table.ans-table td{border:1px solid var(--line);padding:6px 9px;text-align:left;}
table.ans-table th{background:#f1f5f9;}
.mark-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(116px,1fr));gap:8px;margin-top:10px;}
.mark-cell{border:1px solid var(--line);border-radius:8px;padding:8px;text-align:center;}
.vocab-group{margin:14px 0 6px;font-size:14px;color:var(--accent);border-left:3px solid var(--accent);padding-left:8px;}
.vocab-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:8px;}
.ak-images{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:12px;margin-top:10px;}
.ak-images img{width:100%;height:auto;border:1px solid var(--line);border-radius:8px;cursor:zoom-in;}