*{box-sizing:border-box}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;color:#1d2433;background:#f5f7fa;line-height:1.5}
a{color:var(--brand)}
header.top{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:12px;padding:12px 24px;background:#fff;border-bottom:4px solid var(--brand)}
header .brand{text-decoration:none;color:var(--brand);font-weight:700;font-size:20px}
header .logo{height:44px;display:block}
nav{display:flex;flex-wrap:wrap;align-items:center;gap:16px}
nav a{text-decoration:none;font-weight:600;color:#1d2433}
nav a:hover{color:var(--brand)}
main{max-width:960px;margin:28px auto;padding:0 20px}
main.wide{max-width:1280px}
footer{text-align:center;color:#7a8394;font-size:13px;padding:32px 0}
h1{font-size:26px;margin:0 0 16px}h2{font-size:20px;margin:28px 0 12px}
.card{background:#fff;border:1px solid #e1e5ec;border-radius:10px;padding:20px;margin-bottom:16px}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(270px,1fr));gap:16px}
.course .num{display:inline-block;background:var(--brand);color:#fff;border-radius:50%;width:28px;height:28px;text-align:center;line-height:28px;font-weight:700;margin-right:8px;font-size:14px}
.course h3{margin:0 0 6px;font-size:17px}
.muted{color:#6b7385;font-size:14px}
.btn,button{display:inline-block;background:var(--brand);color:#fff;border:0;border-radius:6px;padding:10px 18px;font-size:15px;font-weight:600;cursor:pointer;text-decoration:none}
.btn.secondary,button.secondary{background:#fff;color:var(--brand);border:1px solid var(--brand)}
.btn.danger,button.danger{background:#b42318}
button.link{background:none;color:#1d2433;padding:0;font-weight:600}
button.small,.btn.small{padding:6px 12px;font-size:13px}
form.inline{display:inline}
label{display:block;font-weight:600;margin:12px 0 4px}
input[type=text],input[type=email],input[type=password],input[type=number],input[type=search],select,textarea{width:100%;padding:10px;border:1px solid #c9d0db;border-radius:6px;font-size:15px;background:#fff}
textarea{min-height:90px}
.check{display:flex;gap:8px;align-items:center;font-weight:500}
.check input{width:auto}
.flash{padding:12px 16px;border-radius:8px;margin-bottom:16px;font-weight:600}
.flash.ok{background:#e7f6ec;color:#146c2e}.flash.err{background:#fdecea;color:#912018}.flash.info{background:#eaf2fb;color:#174a7e}
table{width:100%;border-collapse:collapse;background:#fff;font-size:14px}
th,td{text-align:left;padding:9px 10px;border-bottom:1px solid #e8ebf0;vertical-align:top}
th{background:#f0f3f7;font-weight:700}
.badge{display:inline-block;padding:2px 9px;border-radius:999px;font-size:12px;font-weight:700;background:#eef1f5;color:#3b4456}
.badge.ok{background:#e7f6ec;color:#146c2e}.badge.warn{background:#fff4e0;color:#8a5300}.badge.err{background:#fdecea;color:#912018}.badge.info{background:#eaf2fb;color:#174a7e}
.progress{height:8px;background:#e8ebf0;border-radius:4px;overflow:hidden;margin:10px 0}
.progress span{display:block;height:100%;background:var(--brand)}
.next{border:2px solid var(--brand)}
.row{display:flex;gap:12px;flex-wrap:wrap;align-items:center}
.cols{display:grid;grid-template-columns:1fr 1fr;gap:16px}
@media(max-width:700px){.cols{grid-template-columns:1fr}header.top{padding:10px 14px}}
.code{font-family:ui-monospace,Menlo,monospace;font-size:22px;letter-spacing:2px;background:#f0f3f7;padding:10px 16px;border-radius:8px;display:inline-block}
.sortable li{list-style:none;background:#fff;border:1px solid #e1e5ec;border-radius:8px;padding:10px 14px;margin-bottom:8px;cursor:grab;display:flex;justify-content:space-between;gap:12px}
.sortable{padding:0}
.sortable li.dragging{opacity:.5}
.player-wrap{position:fixed;inset:0;display:flex;flex-direction:column;background:#000}
.player-bar{background:#fff;padding:8px 14px;display:flex;justify-content:space-between;align-items:center;border-bottom:3px solid var(--brand)}
.player-wrap iframe{flex:1;border:0;width:100%;background:#fff}
.stat{font-size:28px;font-weight:800;color:var(--brand)}