:root{--primary:#087da9;--primary-dark:#075e82;--bg:#f4f7fb;--text:#172033;--muted:#667085;--card:#fff;--border:#dfe7f1;--ok:#0d8f5b;--warn:#d9822b;--danger:#bc2f3f}*{box-sizing:border-box}body{margin:0;font-family:Inter,Segoe UI,Roboto,Arial,sans-serif;background:var(--bg);color:var(--text)}a{color:var(--primary);text-decoration:none}.layout{display:grid;grid-template-columns:260px 1fr;min-height:100vh}.sidebar{background:#0b2638;color:#fff;padding:24px;position:sticky;top:0;height:100vh}.brand{font-size:22px;font-weight:800;margin-bottom:32px}.nav a{display:block;color:#e9f6fb;padding:11px 12px;border-radius:10px;margin:4px 0}.nav a:hover,.nav a.active{background:rgba(255,255,255,.12)}.main{padding:28px}.topbar{display:flex;justify-content:space-between;align-items:center;margin-bottom:24px}.card{background:var(--card);border:1px solid var(--border);border-radius:18px;padding:22px;box-shadow:0 10px 24px rgba(20,34,56,.04);margin-bottom:18px}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:16px}.stat{font-size:30px;font-weight:800;color:var(--primary)}.muted{color:var(--muted)}.btn{display:inline-flex;align-items:center;justify-content:center;border:0;background:var(--primary);color:#fff;border-radius:10px;padding:10px 14px;font-weight:700;cursor:pointer}.btn.secondary{background:#eaf6fa;color:var(--primary-dark)}.btn.danger{background:var(--danger)}input,select,textarea{width:100%;border:1px solid var(--border);border-radius:10px;padding:11px 12px;font:inherit;background:#fff}label{display:block;font-weight:700;margin:10px 0 6px}.form-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:12px}.table{width:100%;border-collapse:collapse}.table th,.table td{padding:12px;border-bottom:1px solid var(--border);text-align:left}.badge{display:inline-flex;border-radius:999px;padding:5px 10px;font-size:12px;background:#eaf6fa;color:var(--primary-dark);font-weight:800}.progress{height:10px;background:#e9eef5;border-radius:99px;overflow:hidden}.progress span{display:block;height:100%;background:var(--primary)}.course-cover{height:120px;border-radius:16px;background:linear-gradient(135deg,#087da9,#00b8c9);display:flex;align-items:center;justify-content:center;color:#fff;font-weight:900;font-size:36px}.sections.collapsed details{border:1px solid var(--border);border-radius:16px;background:#fff;margin:14px 0;padding:6px 16px}.sections.collapsed summary{font-weight:800;cursor:pointer;padding:14px}.activity{display:flex;align-items:center;justify-content:space-between;padding:12px 0;border-top:1px solid var(--border)}.trail{position:relative;padding:40px 0}.trail:before{content:"";position:absolute;left:6%;right:6%;top:50%;height:16px;background:#83d0dc;border-radius:99px;z-index:0}.trail-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:32px;position:relative;z-index:1}.trail-node{background:linear-gradient(180deg,#11c5c9,#10237c);color:white;border-radius:22px 22px 40px 40px;padding:22px;text-align:center;font-weight:900;box-shadow:0 10px 20px rgba(0,0,0,.16)}.trail-node.done{outline:4px solid #ffd36a}.auth-page{min-height:100vh;display:grid;place-items:center;background:linear-gradient(135deg,#0b2638,#087da9)}.auth-card{width:min(440px,92vw);background:#fff;padding:34px;border-radius:22px;box-shadow:0 18px 44px rgba(0,0,0,.25)}.error{background:#feecef;color:#9f1d35;padding:12px;border-radius:10px;margin-bottom:12px}.video-frame{width:100%;aspect-ratio:16/9;border:0;border-radius:16px;background:#000}.public-wrap{max-width:900px;margin:40px auto;padding:0 18px}.valid{border-left:6px solid var(--ok)}.expired{border-left:6px solid var(--warn)}.revoked,.not_found{border-left:6px solid var(--danger)}@media(max-width:860px){.layout{grid-template-columns:1fr}.sidebar{height:auto;position:relative}.main{padding:18px}.topbar{display:block}.activity{display:block}.trail:before{left:50%;right:auto;top:0;bottom:0;width:16px;height:auto}.trail-grid{grid-template-columns:1fr;max-width:240px;margin:auto}}