:root{--bg:#f7f7fb;--card:#fff;--ink:#172033;--muted:#667085;--brand:#155eef;--ok:#067647;--bad:#b42318;--line:#e4e7ec}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);font-family:system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif}
.topbar{position:sticky;top:0;z-index:5;background:#fff;border-bottom:1px solid var(--line);display:flex;gap:16px;justify-content:space-between;align-items:center;padding:12px 16px}
.topbar small{display:block;color:var(--muted);font-size:12px}
.topbar nav{display:flex;gap:8px;flex-wrap:wrap}
button,.btn{border:0;border-radius:10px;background:var(--brand);color:#fff;padding:10px 14px;font-weight:700;cursor:pointer;text-decoration:none;display:inline-block}
button.secondary,.btn.secondary{background:#eef4ff;color:#155eef}
button.ghost{background:#fff;color:var(--ink);border:1px solid var(--line)}
button.danger{background:#fee4e2;color:#b42318}
main{max-width:1100px;margin:0 auto;padding:18px}
.grid{display:grid;gap:14px}
.grid.cols{grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}
.card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:16px;box-shadow:0 1px 2px rgba(16,24,40,.04)}
.hero{background:linear-gradient(135deg,#eef4ff,#fff);border:1px solid #c7d7fe}
.muted{color:var(--muted)}
.stat{font-size:28px;font-weight:800}
.list{display:grid;gap:8px}
.row{display:flex;justify-content:space-between;gap:12px;align-items:center;border:1px solid var(--line);border-radius:12px;padding:12px;background:#fff}
.video{width:100%;max-height:52vh;background:#000;border-radius:14px}
.qbox{border:1px solid var(--line);border-radius:14px;padding:12px;margin:10px 0;background:#fcfcfd}
.options{display:grid;gap:8px;margin-top:8px}
.option{display:block;padding:10px;border:1px solid var(--line);border-radius:10px;background:#fff;cursor:pointer}
.option input{margin-right:8px;width:auto}
.pill{display:inline-flex;align-items:center;border-radius:999px;background:#f2f4f7;color:#344054;padding:4px 9px;font-size:12px;font-weight:700}
.ok{color:var(--ok)}
.bad{color:var(--bad)}
.timer{font-size:22px;font-weight:800;color:#b42318}
.examnav{display:flex;gap:6px;flex-wrap:wrap;margin:12px 0}
.examnav button{background:#f2f4f7;color:#344054;padding:8px 11px}
.examnav button.active{background:var(--brand);color:#fff}
.examnav button.done{outline:2px solid #12b76a}
.paywall{border-color:#fedf89;background:#fffaeb}
label{display:block;font-weight:700;margin:12px 0 6px}
input,textarea{width:100%;border:1px solid var(--line);border-radius:10px;padding:10px;font:inherit;background:#fff;margin-top:6px}
textarea{min-height:90px;resize:vertical}
.guest-only,.auth-only,.student-only,.admin-only{display:none}
@media(max-width:700px){.topbar{align-items:flex-start;flex-direction:column}.row{align-items:flex-start;flex-direction:column}main{padding:12px}}