:root{
  --navy:#0A1940; --navy2:#13275c; --gold:#FCB707; --gold2:#ffd35a;
  --bg:#f3f5f9; --card:#fff; --ink:#1d2433; --mute:#6b7385; --line:#e3e7ef;
  --ok:#14a35c; --bad:#d64545; --warn:#e08a00;
  --r:14px; --sh:0 1px 2px rgba(10,25,64,.06),0 4px 14px rgba(10,25,64,.06);
}
*{box-sizing:border-box}
html,body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.45 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;-webkit-text-size-adjust:100%}
body{min-height:100vh}
button,input,textarea,select{font:inherit;color:inherit}
a{color:var(--navy2)}
.hidden{display:none!important}
.muted{color:var(--mute)} .small{font-size:13px} .tiny{font-size:12px}
.row{display:flex;align-items:center;gap:10px} .grow{flex:1;min-width:0} .wrap{flex-wrap:wrap}
.ellipsis{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}

/* top bar */
.top{position:sticky;top:0;z-index:20;background:var(--navy);color:#fff;padding:10px 16px;display:flex;align-items:center;gap:10px}
.brand{display:flex;align-items:center;gap:9px;font-weight:700;font-size:16px;cursor:pointer;letter-spacing:.2px}
.brand .bn2{color:var(--gold);font-weight:600}
@media(max-width:420px){.brand .bn{display:flex;flex-direction:column;line-height:1.1;font-size:14px}.brand .bn2{font-size:11px}}
.brand .dot{width:26px;height:26px;border-radius:8px;background:var(--gold);color:var(--navy);display:grid;place-items:center;font-size:15px}
.me{margin-left:auto;display:flex;align-items:center;gap:8px;background:rgba(255,255,255,.1);border:0;color:#fff;border-radius:20px;padding:5px 10px 5px 5px;cursor:pointer}
.av{width:26px;height:26px;border-radius:50%;background:var(--gold);color:var(--navy);display:grid;place-items:center;font-weight:700;font-size:12px;flex:none}
.tabs{display:flex;gap:4px;overflow-x:auto;background:var(--navy);padding:0 12px 8px;position:sticky;top:46px;z-index:19;scrollbar-width:none}
.tabs::-webkit-scrollbar{display:none}
.tab{flex:none;border:0;background:transparent;color:#c9d2ea;padding:7px 12px;border-radius:18px;cursor:pointer;font-size:14px;white-space:nowrap}
.tab.on{background:var(--gold);color:var(--navy);font-weight:700}
.badge{display:inline-block;min-width:18px;padding:0 5px;border-radius:9px;background:var(--bad);color:#fff;font-size:11px;line-height:18px;text-align:center;margin-left:4px;font-weight:700}

main{max-width:980px;margin:0 auto;padding:16px 16px 90px}
h1{font-size:21px;margin:4px 0 14px} h2{font-size:17px;margin:20px 0 10px} h3{font-size:15px;margin:0}
.card{background:var(--card);border-radius:var(--r);box-shadow:var(--sh);padding:14px}
.grid{display:grid;gap:12px;grid-template-columns:1fr}
@media(min-width:640px){.grid{grid-template-columns:1fr 1fr}}
@media(min-width:900px){.grid.g3{grid-template-columns:1fr 1fr 1fr}}

.btn{border:0;border-radius:10px;padding:10px 16px;cursor:pointer;font-weight:600;background:var(--navy);color:#fff;display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:42px}
.btn.gold{background:var(--gold);color:var(--navy)} .btn.ghost{background:#eef1f7;color:var(--navy)}
.btn.red{background:#fdecec;color:var(--bad)} .btn.green{background:#e6f7ee;color:var(--ok)}
.btn.sm{padding:6px 11px;min-height:34px;font-size:13px;border-radius:8px}
.btn.block{width:100%} .btn:disabled{opacity:.5;cursor:not-allowed}
.icon-btn{border:0;background:#eef1f7;border-radius:8px;width:34px;height:34px;cursor:pointer;display:grid;place-items:center;color:var(--navy);flex:none}

label.f{display:block;margin:12px 0 5px;font-weight:600;font-size:13px;color:#3b4459}
.in{width:100%;border:1px solid var(--line);border-radius:10px;padding:11px 12px;background:#fff;outline:none}
.in:focus{border-color:var(--navy2);box-shadow:0 0 0 3px rgba(19,39,92,.12)}
textarea.in{min-height:110px;resize:vertical}
.chips{display:flex;flex-wrap:wrap;gap:6px}
.chip{border:1px solid var(--line);background:#fff;border-radius:16px;padding:5px 11px;cursor:pointer;font-size:13px}
.chip.on{background:var(--navy);color:#fff;border-color:var(--navy)}
.pill{display:inline-block;font-size:11px;font-weight:700;padding:2px 8px;border-radius:10px;background:#eef1f7;color:var(--navy2)}
.pill.ok{background:#e6f7ee;color:var(--ok)} .pill.bad{background:#fdecec;color:var(--bad)} .pill.warn{background:#fff4dc;color:var(--warn)}
.switch{position:relative;width:44px;height:26px;flex:none}
.switch input{opacity:0;width:0;height:0}
.switch span{position:absolute;inset:0;background:#cfd5e2;border-radius:13px;transition:.2s;cursor:pointer}
.switch span:before{content:"";position:absolute;width:20px;height:20px;left:3px;top:3px;background:#fff;border-radius:50%;transition:.2s}
.switch input:checked+span{background:var(--ok)} .switch input:checked+span:before{transform:translateX(18px)}

/* progress */
.bar{height:8px;background:#e8ecf4;border-radius:5px;overflow:hidden}
.bar i{display:block;height:100%;background:linear-gradient(90deg,var(--gold),#f59e0b);border-radius:5px}

/* auth screens */
.auth{min-height:100vh;display:grid;place-items:center;padding:20px;background:radial-gradient(1200px 500px at 50% -10%,#1b3477,var(--navy))}
.auth .box{width:100%;max-width:380px;background:#fff;border-radius:18px;padding:24px 22px;box-shadow:0 20px 50px rgba(0,0,0,.3)}
.auth .logo{display:flex;align-items:center;gap:10px;font-weight:800;font-size:19px;color:var(--navy);margin-bottom:6px}
.auth .logo .sub{font-size:13px;font-weight:600;color:var(--mute);letter-spacing:.3px}
.auth .logo{line-height:1.15}
.auth .logo .dot{width:34px;height:34px;border-radius:10px;background:var(--gold);display:grid;place-items:center;font-size:19px}
.otp{letter-spacing:12px;font-size:28px;text-align:center;font-weight:700;padding:12px}
.err{background:#fdecec;color:var(--bad);border-radius:10px;padding:9px 12px;margin-top:12px;font-size:14px}
.info{background:#fff8e1;color:#7a5600;border-radius:10px;padding:9px 12px;margin-top:12px;font-size:14px}
.lock-ic{font-size:40px;text-align:center;margin:6px 0}

/* course cards */
.course{cursor:pointer;display:flex;flex-direction:column;gap:10px;border-top:5px solid var(--gold)}
.course:hover{transform:translateY(-1px)}
.lesson{display:flex;align-items:center;gap:12px;padding:12px;border-radius:12px;background:#fff;box-shadow:var(--sh);cursor:pointer;margin-bottom:8px}
.lesson .n{width:32px;height:32px;border-radius:50%;background:#eef1f7;display:grid;place-items:center;font-weight:700;color:var(--navy);flex:none;font-size:13px}
.lesson .n.done{background:var(--ok);color:#fff}
.back{border:0;background:none;color:var(--navy2);font-weight:600;padding:4px 0;cursor:pointer;margin-bottom:6px}

/* player */
.stage{position:relative;background:#000;border-radius:12px;overflow:hidden;aspect-ratio:16/9;user-select:none;-webkit-user-select:none;-webkit-touch-callout:none}
.stage .eng{position:absolute;inset:0;z-index:0}
.stage video{width:100%;height:100%;display:block;object-fit:contain;pointer-events:none}
.stage .ytbox,.stage .ytbox iframe{position:absolute;inset:0;width:100%;height:100%;border:0}
.stage .cover{position:absolute;inset:0;z-index:1;display:none;background:#0A1940 center/cover no-repeat}
.stage .cover:after{content:"";position:absolute;inset:0;background:rgba(10,25,64,.55)}
.stage .cover.on{display:block}
.stage .msg{z-index:2!important}
.stage.direct .tap,.stage.direct .cover{display:none!important}
.stage .hint{position:absolute;left:50%;top:14px;transform:translateX(-50%);z-index:6;background:var(--gold);color:var(--navy);font-weight:700;font-size:13px;padding:6px 12px;border-radius:16px;pointer-events:none}
.stage.desk .wm{font-size:15px}
.stage.desk .tilewm{opacity:.16}
.yt-prev{display:flex;gap:10px;align-items:center;margin-top:8px}
.yt-prev img{width:120px;aspect-ratio:16/9;object-fit:cover;border-radius:8px;background:#000}
.stage .tilewm{position:absolute;inset:0;pointer-events:none;opacity:.13;background-repeat:repeat}
.stage .wm{position:absolute;pointer-events:none;color:rgba(255,255,255,.55);font-size:12px;font-weight:700;text-shadow:0 0 3px rgba(0,0,0,.8);white-space:nowrap;transition:left 1.2s ease,top 1.2s ease;z-index:3}
.stage .tap{position:absolute;inset:0 0 48px 0;z-index:2;cursor:pointer}
.stage .big{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);width:66px;height:66px;border-radius:50%;background:rgba(252,183,7,.95);color:var(--navy);display:grid;place-items:center;font-size:26px;z-index:4;border:0;cursor:pointer}
.stage .ctrl{position:absolute;left:0;right:0;bottom:0;z-index:5;display:flex;align-items:center;gap:8px;padding:8px 10px;background:linear-gradient(transparent,rgba(0,0,0,.75));color:#fff}
.stage .ctrl button{border:0;background:transparent;color:#fff;cursor:pointer;font-size:16px;width:32px;height:32px;display:grid;place-items:center;flex:none}
.stage .ctrl .t{font-size:12px;font-variant-numeric:tabular-nums;flex:none}
.stage .ctrl input[type=range]{flex:1;accent-color:var(--gold);min-width:40px}
.stage .ctrl select{background:rgba(255,255,255,.15);border:0;border-radius:6px;color:#fff;font-size:12px;padding:3px}
.stage .shield{position:absolute;inset:0;z-index:8;background:#0A1940;color:#fff;display:grid;place-items:center;text-align:center;padding:20px}
.stage .msg{position:absolute;inset:0;display:grid;place-items:center;color:#fff;z-index:1;font-size:14px}
.stage.fs{position:fixed;inset:0;z-index:100;border-radius:0;aspect-ratio:auto;width:100vw;height:100vh;height:100dvh}
.stage:fullscreen{border-radius:0;aspect-ratio:auto}
.notes{white-space:pre-wrap;word-wrap:break-word}
.files a{display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:10px;background:#f6f8fc;margin-top:6px;text-decoration:none;color:var(--ink);cursor:pointer}

/* sheets */
.sheet-bg{position:fixed;inset:0;background:rgba(10,25,64,.45);z-index:50;display:flex;align-items:flex-end;justify-content:center}
.sheet{background:#fff;width:100%;max-width:640px;max-height:92vh;overflow:auto;border-radius:18px 18px 0 0;padding:16px 16px 24px}
@media(min-width:700px){.sheet-bg{align-items:center}.sheet{border-radius:18px}}
.sheet .hd{display:flex;align-items:center;gap:10px;margin-bottom:6px;position:sticky;top:-16px;background:#fff;padding:6px 0;z-index:2}
.sheet .hd h3{flex:1;font-size:17px}
.toast{position:fixed;left:50%;bottom:22px;transform:translateX(-50%);background:var(--navy);color:#fff;padding:10px 16px;border-radius:10px;z-index:200;box-shadow:0 6px 20px rgba(0,0,0,.25);max-width:92vw;font-size:14px}
.list-item{display:flex;align-items:center;gap:10px;padding:11px 0;border-bottom:1px solid var(--line)}
.list-item:last-child{border-bottom:0}
.up{height:6px;background:#e8ecf4;border-radius:4px;overflow:hidden;margin-top:6px}.up i{display:block;height:100%;background:var(--ok);width:0}
table.t{width:100%;border-collapse:collapse;font-size:13px}
table.t th{text-align:left;color:var(--mute);font-weight:600;padding:6px 4px;border-bottom:1px solid var(--line)}
table.t td{padding:8px 4px;border-bottom:1px solid var(--line);vertical-align:top}
.empty{text-align:center;color:var(--mute);padding:30px 10px}
.color-dot{width:26px;height:26px;border-radius:50%;cursor:pointer;border:3px solid #fff;box-shadow:0 0 0 1px var(--line)}
.color-dot.on{box-shadow:0 0 0 2px var(--navy)}
.spin{width:22px;height:22px;border:3px solid #dfe4ee;border-top-color:var(--navy);border-radius:50%;animation:sp 0.8s linear infinite;margin:40px auto}
@keyframes sp{to{transform:rotate(360deg)}}
@media print{body{display:none!important}}