:root { --ink:#1b2430; --muted:#5d6b7a; --line:#dde3ea; --brand:#0f6cbd; --ok:#1e7d32; --bad:#b3261e; --bg:#f6f8fa; }
* { box-sizing: border-box; }
body { margin:0; font:16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; color:var(--ink); background:var(--bg); }
a { color:var(--brand); }
.topbar { display:flex; justify-content:space-between; align-items:center; padding:.8rem 1.5rem; background:#fff; border-bottom:1px solid var(--line); }
.brand { font-weight:700; text-decoration:none; color:var(--ink); } .brand span { color:var(--brand); }
.topbar nav { display:flex; gap:1rem; align-items:center; }
main { max-width:960px; margin:2rem auto; padding:0 1rem; }
.card { background:#fff; border:1px solid var(--line); border-radius:10px; padding:1.25rem 1.5rem; margin-bottom:1.25rem; }
.narrow { max-width:420px; margin:3rem auto; }
.grid { display:grid; grid-template-columns:repeat(auto-fill, minmax(260px, 1fr)); gap:1rem; }
label { display:block; margin:.6rem 0; font-weight:600; }
input, select { width:100%; padding:.55rem .7rem; border:1px solid var(--line); border-radius:6px; font:inherit; margin-top:.25rem; }
form.inline { display:inline; } form.inline select { width:auto; }
.btn { display:inline-block; background:var(--brand); color:#fff; border:0; border-radius:6px; padding:.6rem 1rem; font:inherit; cursor:pointer; text-decoration:none; }
.btn.small { padding:.3rem .6rem; font-size:.85rem; }
button.link { background:none; border:0; color:var(--brand); cursor:pointer; font:inherit; padding:0; }
.alert { background:#fdecea; color:var(--bad); padding:.7rem 1rem; border-radius:6px; } .alert.ok { background:#e8f5e9; color:var(--ok); }
.muted { color:var(--muted); font-size:.9rem; }
.badge { background:#eee; padding:.3rem .6rem; border-radius:99px; font-size:.85rem; }
progress { width:100%; height:8px; appearance:none; border:0; border-radius:99px; background:#e9edf1; overflow:hidden; }
progress::-webkit-progress-bar { background:#e9edf1; } progress::-webkit-progress-value { background:var(--ok); } progress::-moz-progress-bar { background:var(--ok); }
.bar { height:8px; background:#e9edf1; border-radius:99px; overflow:hidden; } .bar span { display:block; height:100%; background:var(--ok); }
.lessons { padding-left:1.2rem; } .lessons li { padding:.6rem 0; border-bottom:1px solid var(--line); }
.lessons small { display:block; color:var(--muted); } .lessons .locked span { color:var(--muted); }
.video { position:relative; aspect-ratio:16/9; background:#000; border-radius:10px; overflow:hidden; margin-bottom:.5rem; }
.video iframe, .video #player { position:absolute; inset:0; width:100%; height:100%; }
fieldset { border:1px solid var(--line); border-radius:8px; margin:0 0 1rem; } legend { font-weight:600; padding:0 .4rem; }
label.opt { font-weight:400; } label.opt input { width:auto; margin-right:.4rem; }
.scroll { overflow-x:auto; } table { border-collapse:collapse; width:100%; } th, td { border-bottom:1px solid var(--line); padding:.5rem; text-align:left; vertical-align:top; }
tr.inactive { opacity:.5; }
.foot { text-align:center; color:var(--muted); font-size:.85rem; padding:2rem 1rem; }
.hp { position:absolute; left:-9999px; width:1px; height:1px; overflow:hidden; }
.stack > * { margin-bottom:.5rem; }
textarea { width:100%; min-height:7rem; padding:.55rem .7rem; border:1px solid var(--line); border-radius:6px; font:inherit; margin-top:.25rem; }
details.card > summary { cursor:pointer; font-weight:600; }
.row { display:flex; gap:.75rem; flex-wrap:wrap; align-items:end; } .row > label { flex:1; min-width:140px; }
.checks { list-style:none; padding:0; } .checks .pass { color:var(--ok); } .checks .fail { color:var(--bad); font-weight:600; }