:root{
  --bg:#f4f6f9;--card:#fff;--ink:#1a2233;--muted:#5a6478;--line:#e2e7f0;
  --brand:#2f5fd0;--brand-dark:#1f3f8f;--brand-soft:#e8effc;
  --green:#1d8a50;--green-soft:#e5f7ee;--amber:#b26a00;--amber-soft:#fff3dd;
  --red:#c0392b;--red-soft:#fdeceb;--radius:12px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:"Segoe UI","Nirmala UI","Mangal","Helvetica Neue",Arial,sans-serif;background:var(--bg);color:var(--ink);line-height:1.55;font-size:16px}
button{font:inherit}
a{color:var(--brand)}

/* start */
.start-overlay{position:fixed;inset:0;z-index:100;display:flex;align-items:center;justify-content:center;padding:22px;overflow:auto;background:linear-gradient(135deg,#10224d 0%,#1f3f8f 48%,#2f5fd0 100%)}
.start-overlay[hidden]{display:none!important}
.start-card{background:#fff;width:100%;max-width:660px;border-radius:18px;padding:28px 30px;box-shadow:0 24px 70px rgba(0,0,0,.35)}
.eyebrow{font-size:.7rem;font-weight:800;letter-spacing:.12em;text-transform:uppercase;color:var(--brand)}
.start-card h1{font-size:1.55rem;line-height:1.25;margin:6px 0 4px}
.start-sub{color:var(--muted);font-size:.9rem}
.name-box{margin:20px 0 10px}
.name-box label{display:block;font-size:.78rem;font-weight:800;text-transform:uppercase;letter-spacing:.06em;color:var(--muted);margin-bottom:5px}
.name-box input{width:100%;border:1px solid var(--line);border-radius:10px;padding:11px 13px;font:inherit;font-size:.95rem;outline:none;background:#fbfcfe}
.name-box input:focus{border-color:#93b5ee;box-shadow:0 0 0 3px #dbe7ff}
.hint{font-size:.75rem;color:var(--muted);margin-top:6px}
.rules{margin:16px 0 0 18px;font-size:.84rem;color:var(--muted)}
.rules li{margin:5px 0}

/* language switch */
.lang-switch{display:inline-flex;gap:3px;padding:3px;border-radius:9px;background:var(--brand-soft);border:1px solid #d6e2fb}
.lang-btn{border:0;background:transparent;border-radius:7px;padding:5px 13px;font-size:.78rem;font-weight:700;color:var(--brand-dark);cursor:pointer;white-space:nowrap}
.lang-btn:hover{background:#dbe7ff}
.lang-btn.active{background:linear-gradient(135deg,var(--brand-dark),var(--brand));color:#fff}
.start-card .lang-switch{margin-top:12px}
.start-actions{display:flex;gap:9px;flex-wrap:wrap;margin-top:18px}
.btn{display:inline-flex;align-items:center;justify-content:center;border:1px solid var(--line);background:#fff;color:var(--ink);border-radius:9px;padding:9px 14px;font-size:.84rem;font-weight:700;cursor:pointer;text-decoration:none}
.btn:hover{border-color:#b9c8e8;background:#f8faff}
.btn.primary{background:linear-gradient(135deg,var(--brand-dark),var(--brand));border-color:transparent;color:#fff}
.btn.primary:hover{filter:brightness(1.06)}
.btn:disabled{opacity:.6;cursor:default}
.btn[hidden]{display:none!important}
.msg{border-radius:9px;padding:9px 11px;font-size:.82rem;margin-top:10px}
.msg.error{background:var(--red-soft);border:1px solid #f3b9b3;color:var(--red)}
.msg.info{background:var(--brand-soft);border:1px solid #cfdefb;color:var(--brand-dark)}
.msg[hidden]{display:none!important}

/* header */
.exam-header{position:sticky;top:0;z-index:50;background:linear-gradient(135deg,#1f3f8f 0%,#2f5fd0 62%,#4a7de0 100%);color:#fff;box-shadow:0 3px 14px rgba(15,35,80,.22)}
.exam-header[hidden]{display:none!important}
.exam-header .inner{max-width:980px;margin:0 auto;padding:9px 16px;display:flex;align-items:center;gap:9px;flex-wrap:wrap}
.exam-heading{min-width:140px}
.exam-title{font-size:.86rem;font-weight:800}
.exam-sub{font-size:.68rem;opacity:.85}
.timer{margin-left:auto;background:rgba(255,255,255,.14);border:1px solid rgba(255,255,255,.32);border-radius:999px;padding:6px 12px;font-weight:800;font-variant-numeric:tabular-nums;letter-spacing:.04em;font-size:.84rem;white-space:nowrap}
.timer.warn{background:var(--amber-soft);border-color:#f0d8a8;color:var(--amber)}
.timer.danger{background:var(--red-soft);border-color:#f3b9b3;color:var(--red)}
.progress-pill{background:rgba(255,255,255,.14);border:1px solid rgba(255,255,255,.32);border-radius:999px;padding:6px 10px;font-size:.74rem;font-weight:700;white-space:nowrap}
.hbtn{border:1px solid rgba(255,255,255,.45);background:rgba(255,255,255,.12);color:#fff;border-radius:8px;padding:6px 10px;font-size:.74rem;font-weight:700;cursor:pointer;white-space:nowrap}
.hbtn:hover{background:rgba(255,255,255,.22)}
.hbtn.primary{background:#fff;color:var(--brand-dark);border-color:#fff}
.hbtn.primary:hover{background:#eef4ff}
.hbtn:disabled{opacity:.55;cursor:default}
.exam-header .lang-switch{background:rgba(255,255,255,.12);border-color:rgba(255,255,255,.32)}
.exam-header .lang-btn{color:#fff}
.exam-header .lang-btn:hover{background:rgba(255,255,255,.22)}
.exam-header .lang-btn.active{background:#fff;color:var(--brand-dark)}

/* main/questions */
.wrap{max-width:980px;margin:0 auto;padding:18px 16px 70px}
.q-list{display:flex;flex-direction:column;gap:11px}
.q-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:15px 17px;box-shadow:0 1px 3px rgba(30,50,90,.05);scroll-margin-top:86px}
.q-no{display:inline-block;background:var(--brand-soft);color:var(--brand-dark);border-radius:999px;font-size:.7rem;font-weight:800;padding:2px 8px;margin-bottom:5px}
.q-text{font-size:.95rem;font-weight:600;white-space:pre-wrap;overflow-wrap:anywhere}
.options{display:grid;grid-template-columns:1fr 1fr;gap:7px;margin-top:10px}
.opt{display:flex;align-items:flex-start;gap:9px;text-align:left;width:100%;border:1px solid var(--line);background:#fbfcfe;border-radius:9px;padding:8px 10px;font-size:.86rem;cursor:pointer;color:var(--ink);white-space:pre-wrap;overflow-wrap:anywhere}
.opt:hover{border-color:#9db9ee;background:#f5f9ff}
.opt .letter{font-weight:800;color:var(--muted);min-width:14px;line-height:1.45}
.opt .opt-text{flex:1;min-width:0}
.opt.selected{border-color:var(--brand);background:var(--brand-soft);box-shadow:0 0 0 2px #d8e5ff}
.opt.selected .letter{color:var(--brand-dark)}
.opt:disabled{cursor:default}
.opt.correct{border-color:#8bd5aa!important;background:var(--green-soft)!important;box-shadow:none!important}
.opt.correct .letter{color:var(--green)}
.opt.wrong{border-color:#efaaa3!important;background:var(--red-soft)!important;box-shadow:none!important}
.opt.wrong .letter{color:var(--red)}
.explain{display:none;margin-top:10px;border-left:4px solid var(--green);background:#f7fffa;border-radius:0 8px 8px 0;padding:9px 11px;font-size:.8rem}
.explain.show{display:block}
.explain strong{color:var(--green)}
.explain p{margin-top:4px;color:#283548;white-space:pre-wrap;overflow-wrap:anywhere}
body.practice .explain{display:none!important}

/* result */
.result-panel{background:#fff;border:1px solid #cfe0d7;border-radius:14px;padding:18px 20px;margin:0 0 18px;box-shadow:0 2px 10px rgba(20,70,45,.06)}
.result-panel[hidden]{display:none!important}
.result-top{display:flex;align-items:center;justify-content:space-between;gap:16px;flex-wrap:wrap}
.score-big{font-size:2rem;font-weight:900;color:var(--brand-dark);line-height:1.1}
.score-sub{color:var(--muted);font-size:.84rem;margin-top:2px}
.chips{display:flex;gap:7px;flex-wrap:wrap}
.chip{font-size:.74rem;font-weight:800;border-radius:999px;padding:4px 9px}
.chip.ok{background:var(--green-soft);color:var(--green)}
.chip.bad{background:var(--red-soft);color:var(--red)}
.chip.skip{background:#eef1f6;color:var(--muted)}
.result-actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:14px}
.result-actions .btn{font-size:.8rem;padding:7px 11px}
.practice-banner{background:var(--amber-soft);border:1px solid #f0d8a8;color:#6d4700;border-radius:9px;padding:8px 11px;font-size:.8rem;margin-bottom:12px}
.practice-banner[hidden]{display:none!important}

/* palette + modal */
.palette-overlay,.modal-overlay{position:fixed;inset:0;z-index:90;background:rgba(15,30,60,.55);display:flex;align-items:flex-start;justify-content:center;padding:26px 16px;overflow:auto}
.palette-overlay[hidden],.modal-overlay[hidden]{display:none!important}
.palette-card{background:#fff;width:100%;max-width:620px;border-radius:14px;padding:18px 20px;box-shadow:0 18px 60px rgba(0,0,0,.3)}
.palette-head{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:8px}
.palette-head h3{font-size:1rem;color:var(--brand-dark)}
.legend{display:flex;gap:12px;flex-wrap:wrap;font-size:.72rem;color:var(--muted);margin-bottom:12px}
.legend span{display:inline-flex;align-items:center;gap:5px}
.dot{width:11px;height:11px;border-radius:3px;border:1px solid #c9d3e3;display:inline-block;background:#fff}
.dot.answered{background:var(--brand-soft);border-color:#9db9ee}
.pal-grid{display:grid;grid-template-columns:repeat(10,1fr);gap:5px}
.pal-btn{border:1px solid var(--line);background:#fff;border-radius:5px;height:28px;font-size:.7rem;font-weight:700;color:var(--muted);cursor:pointer}
.pal-btn:hover{border-color:#9db9ee}
.pal-btn.answered{background:var(--brand-soft);border-color:#9db9ee;color:var(--brand-dark)}
.modal-card{background:#fff;width:100%;max-width:420px;border-radius:12px;padding:20px 22px;box-shadow:0 18px 60px rgba(0,0,0,.3);margin-top:8vh}
.modal-card h3{font-size:1.05rem;margin-bottom:6px;color:var(--brand-dark)}
.modal-card p{font-size:.86rem;color:var(--muted)}
.modal-actions{display:flex;gap:8px;justify-content:flex-end;margin-top:15px;flex-wrap:wrap}
footer{color:var(--muted);font-size:.72rem;padding:0 0 26px;text-align:center}

@media(max-width:720px){
  .start-card{padding:22px 18px}
  .start-card h1{font-size:1.3rem}
  .options{grid-template-columns:1fr}
  .pal-grid{grid-template-columns:repeat(5,1fr)}
  .exam-header{position:static}
  .exam-header .inner{padding:8px 12px;gap:6px}
  .exam-heading{flex:1 1 100%}
  .timer{margin-left:0}
  .wrap{padding:14px 12px 60px}
  .q-card{padding:13px 13px}
}