:root{
  --brand:#0f9d76; --brand-dark:#0b7a5c; --brand-soft:#e6f7f1;
  --ink:#12212b; --ink-2:#4a5c68; --ink-3:#8b9aa5;
  --line:#e6ecf0; --bg:#f6f9fb; --card:#ffffff;
  --gold:#f0a020; --blue:#2f7fe8; --danger:#e2523c;
  --radius:16px; --radius-sm:10px;
  --shadow:0 6px 24px rgba(18,40,55,.07);
  --font:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei","Segoe UI",Roboto,sans-serif;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{background:var(--bg);color:var(--ink);font-family:var(--font);font-size:15px;line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
button{font-family:inherit}
h1,h2,h3,h4{margin:0 0 8px;line-height:1.35}
p{margin:0 0 8px}
img{max-width:100%}

/* ---------- layout ---------- */
.topbar{position:sticky;top:0;z-index:40;background:rgba(255,255,255,.92);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.topbar-inner{max-width:1120px;margin:0 auto;padding:10px 16px;display:flex;align-items:center;gap:16px}
.brand{display:flex;align-items:center;gap:8px;flex:0 0 auto}
.brand-mark{font-size:24px;line-height:1}
.brand-text{display:flex;flex-direction:column;line-height:1.15}
.brand-text strong{font-size:17px;letter-spacing:.5px}
.brand-text em{font-style:normal;font-size:11px;color:var(--ink-3)}
.desk-nav{display:flex;gap:4px;flex:1 1 auto;min-width:0;overflow:auto;scrollbar-width:none}
.desk-nav::-webkit-scrollbar{display:none}
.desk-nav a{padding:6px 10px;border-radius:8px;font-size:14px;color:var(--ink-2);white-space:nowrap}
.desk-nav a:hover{background:var(--brand-soft)}
.desk-nav a.on{background:var(--brand-soft);color:var(--brand-dark);font-weight:600}
.topbar-right{display:flex;align-items:center;gap:8px;flex:0 0 auto}
.points-chip{display:none;font-size:12px;padding:4px 10px;border-radius:999px;background:#fff5e3;color:#a35a00;border:1px solid #ffe0b2}
.points-chip.on{display:inline-block}
.env-banner{max-width:1120px;margin:10px auto 0;padding:8px 12px;border-radius:10px;font-size:12.5px;background:#fff7e6;border:1px solid #ffd591;color:#8a5a00}
.view{max-width:1120px;margin:0 auto;padding:16px 16px 96px}
.tabbar{position:fixed;left:0;right:0;bottom:0;z-index:40;display:none;background:#fff;border-top:1px solid var(--line);padding:6px 4px calc(6px + env(safe-area-inset-bottom))}
.tabbar a{flex:1;display:flex;flex-direction:column;align-items:center;gap:2px;font-size:11px;color:var(--ink-3);padding:4px 0}
.tabbar a.on{color:var(--brand-dark)}
.tabbar a span.ic{font-size:20px;line-height:1}

/* ---------- primitives ---------- */
.btn{border:1px solid var(--line);background:#fff;color:var(--ink);padding:9px 16px;border-radius:10px;font-size:14px;cursor:pointer;transition:.15s}
.btn:hover{border-color:var(--brand);color:var(--brand-dark)}
.btn-primary{background:var(--brand);border-color:var(--brand);color:#fff;font-weight:600}
.btn-primary:hover{background:var(--brand-dark);color:#fff}
.btn-ghost{background:transparent}
.btn-sm{padding:6px 12px;font-size:13px}
.btn-block{width:100%;display:block;text-align:center}
.btn:disabled{opacity:.5;cursor:not-allowed}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}
.pad{padding:16px}
.grid{display:grid;gap:12px}
.grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid-4{grid-template-columns:repeat(4,minmax(0,1fr))}
.row{display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.between{display:flex;align-items:center;justify-content:space-between;gap:8px}
.muted{color:var(--ink-3)}
.small{font-size:12.5px}
.tag{display:inline-block;padding:2px 8px;border-radius:999px;background:var(--brand-soft);color:var(--brand-dark);font-size:11.5px;margin:0 4px 4px 0}
.tag.gray{background:#eef2f5;color:var(--ink-2)}
.tag.gold{background:#fff3d9;color:#8a5a00}
.tag.blue{background:#e8f1ff;color:#1b5bb5}
.tag.red{background:#ffe9e5;color:var(--danger)}
.section-title{display:flex;align-items:center;justify-content:space-between;margin:22px 0 10px}
.section-title h2{font-size:18px}
.filters{display:flex;gap:6px;overflow:auto;padding-bottom:4px;scrollbar-width:none}
.filters::-webkit-scrollbar{display:none}
.filters button{border:1px solid var(--line);background:#fff;border-radius:999px;padding:5px 12px;font-size:13px;color:var(--ink-2);cursor:pointer;white-space:nowrap}
.filters button.on{background:var(--brand);border-color:var(--brand);color:#fff}
.empty{padding:36px 12px;text-align:center;color:var(--ink-3)}
.divider{height:1px;background:var(--line);margin:14px 0}

/* ---------- hero ---------- */
.hero{border-radius:20px;padding:22px;background:linear-gradient(120deg,#0f9d76,#2f7fe8);color:#fff;box-shadow:var(--shadow)}
.hero h1{font-size:26px;margin-bottom:6px}
.hero p{opacity:.92;margin-bottom:14px}
.hero .hero-actions{display:flex;gap:8px;flex-wrap:wrap}
.hero .btn{border-color:transparent}
.hero .btn-primary{background:#fff;color:var(--brand-dark)}
.hero-stats{display:flex;gap:16px;margin-top:16px;flex-wrap:wrap}
.hero-stats div span{display:block;font-size:20px;font-weight:700}
.hero-stats div small{opacity:.85;font-size:12px}

/* ---------- lesson card ---------- */
.lcard{display:flex;flex-direction:column;gap:8px;padding:14px;border:1px solid var(--line);border-radius:var(--radius);background:#fff;cursor:pointer;transition:.15s}
.lcard:hover{transform:translateY(-2px);box-shadow:var(--shadow);border-color:#cfe6dd}
.lcard .cover{font-size:28px}
.lcard h3{font-size:15px;margin:0}
.lcard .sum{font-size:12.5px;color:var(--ink-3);display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;min-height:34px}
.lock{display:inline-flex;align-items:center;gap:4px;font-size:11.5px;color:#8a5a00;background:#fff3d9;border-radius:999px;padding:2px 8px}

/* ---------- learner ---------- */
.line-item{border:1px solid var(--line);border-radius:12px;padding:12px;margin-bottom:8px;background:#fff}
.line-en{font-size:16px;font-weight:600;line-height:1.5}
.line-cn{color:var(--ink-2);font-size:13.5px;margin-top:2px}
.line-tip{font-size:12px;color:var(--ink-3);margin-top:6px;border-left:3px solid var(--brand-soft);padding-left:8px}
.line-item.playing{border-color:var(--brand);background:#f7fdfb}
.word-item{border:1px solid var(--line);border-radius:12px;padding:10px 12px;background:#fff}
.word-top{display:flex;align-items:baseline;gap:6px;flex-wrap:wrap}
.word-top b{font-size:16px}
.word-ph{color:var(--ink-3);font-size:12px}
.word-m{font-size:13.5px;color:var(--ink-2)}
.quiz-box{border:1px dashed var(--brand);border-radius:12px;background:#f8fffd;padding:14px}
.opt{display:block;width:100%;text-align:left;border:1px solid var(--line);background:#fff;border-radius:10px;padding:10px 12px;margin-bottom:8px;cursor:pointer;font-size:14px}
.opt:hover{border-color:var(--brand)}
.opt.right{border-color:var(--brand);background:#e9f8f3}
.opt.wrong{border-color:var(--danger);background:#fff1ee}

/* ---------- game ---------- */
.match-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:8px}
.match-cell{border:1px solid var(--line);border-radius:12px;background:#fff;padding:14px 8px;text-align:center;cursor:pointer;font-size:14px;min-height:56px;display:flex;align-items:center;justify-content:center}
.match-cell.on{border-color:var(--brand);background:var(--brand-soft)}
.match-cell.done{border-color:var(--brand);background:#e9f8f3;color:var(--ink-3);cursor:default}
.match-cell.bad{animation:shake .3s}
@keyframes shake{0%,100%{transform:translateX(0)}25%{transform:translateX(-4px)}75%{transform:translateX(4px)}}
.typing-box{font-size:22px;font-weight:700;letter-spacing:2px;text-align:center;margin:10px 0}
.typing-slot{display:inline-block;min-width:14px;border-bottom:2px solid var(--brand);color:var(--brand-dark)}
.timer{font-size:13px;color:var(--ink-3)}

/* ---------- forms ---------- */
.input,select,textarea{width:100%;padding:10px 12px;border:1px solid var(--line);border-radius:10px;font-size:14px;font-family:inherit;background:#fff;color:var(--ink)}
.input:focus,select:focus,textarea:focus{outline:none;border-color:var(--brand)}
label.fld{display:block;margin-bottom:10px}
label.fld>span{display:block;font-size:12.5px;color:var(--ink-2);margin-bottom:4px}
.err{color:var(--danger);font-size:12.5px;margin-top:4px}
.ok{color:var(--brand-dark);font-size:12.5px;margin-top:4px}

/* ---------- modal / toast ---------- */
.modal-root{position:fixed;inset:0;z-index:80;display:flex;align-items:center;justify-content:center;padding:16px}
.modal-mask{position:absolute;inset:0;background:rgba(12,28,38,.45)}
.modal-card{position:relative;background:#fff;border-radius:18px;width:min(460px,100%);max-height:88vh;overflow:auto;padding:20px;box-shadow:0 20px 60px rgba(0,0,0,.2)}
.toast-root{position:fixed;left:0;right:0;bottom:88px;z-index:100;display:flex;flex-direction:column;align-items:center;gap:8px;pointer-events:none}
.toast{background:rgba(18,33,43,.92);color:#fff;padding:8px 16px;border-radius:999px;font-size:13px;animation:fade .25s}
@keyframes fade{from{opacity:0;transform:translateY(6px)}}

/* ---------- table (admin) ---------- */
.table-wrap{overflow:auto;border:1px solid var(--line);border-radius:12px;background:#fff}
table{width:100%;border-collapse:collapse;font-size:13px;min-width:520px}
th,td{padding:9px 10px;text-align:left;border-bottom:1px solid var(--line);white-space:nowrap}
th{background:#f7fafb;color:var(--ink-2);font-weight:600;position:sticky;top:0}
tr:last-child td{border-bottom:none}
.stat-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:12px}
.stat{padding:14px;border-radius:14px;background:#fff;border:1px solid var(--line)}
.stat b{display:block;font-size:22px}
.stat small{color:var(--ink-3)}
.bars{display:flex;align-items:flex-end;gap:6px;height:110px;padding-top:8px}
.bars div{flex:1;background:linear-gradient(180deg,#2f7fe8,#0f9d76);border-radius:6px 6px 0 0;min-height:3px;position:relative}
.bars div span{position:absolute;top:-16px;left:0;right:0;text-align:center;font-size:10px;color:var(--ink-3)}

/* ---------- responsive ---------- */
@media (max-width:900px){
  .grid-4{grid-template-columns:repeat(2,minmax(0,1fr))}
  .grid-3{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (max-width:720px){
  body{font-size:14.5px}
  .desk-nav{display:none}
  .tabbar{display:flex}
  .view{padding:12px 12px 88px}
  .hero{padding:18px}
  .hero h1{font-size:21px}
  .grid-2,.grid-3,.grid-4{grid-template-columns:repeat(2,minmax(0,1fr))}
  .brand-text em{display:none}
  .modal-card{border-radius:16px 16px 0 0;align-self:flex-end;max-height:92vh}
  .modal-root{padding:0}
  .toast-root{bottom:76px}
}
@media (max-width:400px){
  .grid-2,.grid-3,.grid-4{grid-template-columns:1fr}
}

/* ---------- 底部播放器（外部音源） ---------- */
.playbar{position:fixed;left:0;right:0;bottom:0;z-index:60;background:#fff;border-top:1px solid var(--line);
  box-shadow:0 -4px 18px rgba(18,40,55,.09);display:none}
.playbar.on{display:block}
.pb-inner{max-width:1120px;margin:0 auto;display:flex;align-items:center;gap:12px;padding:10px 16px}
.pb-cover{font-size:24px;width:42px;height:42px;border-radius:10px;background:var(--brand-soft);
  display:flex;align-items:center;justify-content:center;flex:0 0 auto}
.pb-body{flex:1;min-width:0}
.pb-title{font-size:14px;font-weight:600;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.pb-bar{height:5px;background:var(--line);border-radius:999px;margin:5px 0;cursor:pointer}
.pb-bar i{display:block;height:5px;width:0;background:var(--brand);border-radius:999px}
.pb-sub{font-size:11px;color:var(--ink-3)}
.pb-ctrl{display:flex;align-items:center;gap:4px;flex:0 0 auto}
.pb-ctrl button{width:34px;height:34px;border-radius:50%;border:1px solid var(--line);background:#fff;font-size:13px;cursor:pointer;color:var(--ink)}
.pb-ctrl .pb-play{background:var(--brand);border-color:var(--brand);color:#fff;font-size:14px}
#pbRate{width:auto;padding:0 8px;border-radius:999px;font-weight:700;font-size:12px}
#pbRate.pb-rate-slow{background:#fff7e6;border-color:#f0c36d;color:#8a5a00}
[data-play].playing{color:var(--brand-dark);border-color:var(--brand)}
@media (max-width:720px){
  .playbar{bottom:56px}
  .pb-inner{padding:8px 12px;gap:8px}
  .pb-cover{width:36px;height:36px;font-size:20px}
}

/* hidden 属性必须赢过 display:flex，否则空弹窗会常驻盖住整页 */
.modal-root[hidden],.toast-root[hidden],.env-banner[hidden]{display:none!important}