:root{
  --bg:#eef3f8;
  --card:#ffffff;
  --text:#17212b;
  --muted:#66788a;
  --line:#d8e2ec;
  --primary:#1d5d88;
  --primary2:#17496a;
  --danger:#b42318;
  --success:#16794d;
  --warning:#fff4d8;
}
*{box-sizing:border-box}
body{
  margin:0;
  font-family:Arial,Helvetica,sans-serif;
  background:linear-gradient(180deg,#eaf2f8 0%,#f8fafc 100%);
  color:var(--text);
  min-height:100vh;
}
.shell{max-width:1180px;margin:0 auto;padding:28px 18px 50px}
.card{
  background:var(--card);
  border:1px solid var(--line);
  border-radius:16px;
  box-shadow:0 8px 24px rgba(24,50,70,.08);
  padding:24px;
}
.hidden{display:none!important}
.brand{display:flex;gap:16px;align-items:center;margin-bottom:20px}
.brand h1{margin:0 0 5px;font-size:26px}
.brand p{margin:0;color:var(--muted)}
.badge{
  width:62px;height:62px;border-radius:16px;background:var(--primary);
  color:#fff;display:grid;place-items:center;font-weight:700;font-size:18px;
}
.info-box{
  background:#f5f9fc;border:1px solid var(--line);padding:16px 18px;
  border-radius:12px;margin:18px 0 22px;line-height:1.55;
}
.info-box ul{margin:9px 0 0 18px;padding:0}
.form-grid{display:grid;grid-template-columns:1fr 1fr 1fr;gap:14px}
label{font-weight:700;font-size:14px}
input,textarea{
  width:100%;margin-top:7px;border:1px solid #b9c7d5;border-radius:10px;
  padding:12px 13px;font:inherit;background:#fff;color:var(--text);outline:none;
}
input:focus,textarea:focus{border-color:var(--primary);box-shadow:0 0 0 3px rgba(29,93,136,.12)}
textarea{resize:vertical;min-height:260px;line-height:1.5}
.wide{grid-column:1/-1}
.btn{
  border:1px solid #bac7d3;background:#fff;color:var(--text);
  border-radius:10px;padding:11px 16px;font-weight:700;cursor:pointer;
}
.btn:hover{filter:brightness(.98)}
.btn:disabled{opacity:.45;cursor:not-allowed}
.btn.primary{background:var(--primary);border-color:var(--primary);color:#fff}
.btn.primary:hover{background:var(--primary2)}
.btn.danger{background:var(--danger);border-color:var(--danger);color:#fff;margin-left:auto}
.teacher-link{text-align:right;margin-top:18px}
.teacher-link a{color:var(--primary);text-decoration:none;font-weight:700}
.exam-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:16px;padding:16px 20px}
.small{font-size:12px;color:var(--muted);margin-bottom:5px;text-transform:uppercase;letter-spacing:.04em}
.timer-wrap{text-align:right}
.timer{font-size:26px;font-weight:800;letter-spacing:.04em}
.timer.urgent{color:var(--danger)}
.exam-grid{display:grid;grid-template-columns:235px 1fr;gap:16px}
.nav-card{align-self:start}
.nav-card h3{margin-top:0}
.question-nav{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}
.qnav{
  border:1px solid var(--line);background:#f7f9fb;border-radius:9px;
  padding:10px 0;font-weight:700;cursor:pointer;
}
.qnav.answered{background:#e6f6ef;border-color:#9cd7be;color:#11603d}
.qnav.current{outline:3px solid rgba(29,93,136,.18);border-color:var(--primary)}
.legend{display:grid;gap:7px;font-size:12px;color:var(--muted);margin-top:18px}
.dot{display:inline-block;width:10px;height:10px;border-radius:50%;margin-right:6px}
.dot.answered{background:#36a36f}.dot.current{background:var(--primary)}
.violation{margin-top:18px;padding:10px;border-radius:9px;background:#fff7ed;font-size:13px}
.question-top{display:flex;justify-content:space-between;align-items:center;gap:10px}
.pill{background:#e9f2f8;color:#17496a;border-radius:999px;padding:7px 11px;font-weight:700}
.points{font-weight:700;color:var(--muted)}
.question-text{font-size:18px;line-height:1.65;margin:24px 0;white-space:pre-line}
.answer-label{display:block;margin-bottom:2px}
.autosave{font-size:12px;color:var(--muted);margin-top:7px}
.actions{display:flex;gap:10px;margin-top:18px;align-items:center}
.warning{
  margin:0 0 16px;background:var(--warning);border:1px solid #f0cc74;
  color:#6b4b00;border-radius:12px;padding:12px 14px;font-weight:700;
}
.done{text-align:center;max-width:650px;margin:70px auto}
.done-icon{
  width:72px;height:72px;border-radius:50%;display:grid;place-items:center;
  background:#e7f7ef;color:var(--success);font-size:40px;font-weight:800;margin:0 auto 16px;
}
.muted{color:var(--muted)}
.modal{
  position:fixed;inset:0;background:rgba(8,18,28,.62);display:grid;
  place-items:center;padding:18px;z-index:9999;
}
.modal-card{max-width:520px;width:100%;background:#fff;border-radius:16px;padding:24px;box-shadow:0 25px 60px rgba(0,0,0,.28)}
.modal-card h2{margin-top:0}
@media(max-width:780px){
  .form-grid{grid-template-columns:1fr}
  .exam-grid{grid-template-columns:1fr}
  .nav-card{order:2}
  .question-card{order:1}
  .question-nav{grid-template-columns:repeat(8,1fr)}
}
@media(max-width:520px){
  .shell{padding:12px 10px 30px}
  .card{padding:16px;border-radius:12px}
  .brand h1{font-size:21px}
  .question-nav{grid-template-columns:repeat(4,1fr)}
  .actions{flex-wrap:wrap}
  .btn.danger{margin-left:0;width:100%}
}
.exam-exit-note{
  margin:0 0 16px;
  background:#eef6ff;
  border:1px solid #b9d6ee;
  color:#23455f;
  border-radius:12px;
  padding:11px 14px;
  font-size:13px;
  line-height:1.45;
}
.modal-actions{display:flex;gap:10px;justify-content:flex-end;flex-wrap:wrap;margin-top:20px}
.btn.leave{background:#fff;border-color:#b42318;color:#b42318}
.btn.leave:hover{background:#fff5f4}
.leave-icon{
  width:72px;height:72px;border-radius:50%;display:grid;place-items:center;
  background:#fff0ef;color:#b42318;font-size:40px;font-weight:800;margin:0 auto 16px;
}
.server-note{background:#fff8e8;border:1px solid #e9cc7a;border-radius:12px;padding:14px;line-height:1.5}