:root{--surface:#f8f9fa;--card:#fff;--container:#edeeef;--container-low:#f3f4f5;--line:#c0c8c9;--text:#191c1d;--muted:#414849;--primary:#002428;--primary-2:#0d3b40;--cyan:#a3ced4;--blue:#395f94;--lime:#c3f400;--r:.5rem;--rx:.75rem;--shadow:0 18px 45px #395f941f}*{box-sizing:border-box}body{background:var(--surface);color:var(--text);margin:0;font-family:Inter,system-ui,sans-serif}button,input,select{font:inherit}button{cursor:pointer}.eyebrow{letter-spacing:.05em;text-transform:uppercase;color:var(--blue);font-family:Geist,sans-serif;font-size:14px;font-weight:600}.login-shell{background:radial-gradient(circle at 15% 10%,#d5e3ff,transparent 28%),linear-gradient(135deg,var(--surface),#e1e3e4);place-content:center;min-height:100vh;padding:24px;display:grid}.login-card,.video-card,.lesson-list,.admin-card{background:var(--card);border:1px solid var(--line);border-radius:var(--rx);box-shadow:var(--shadow)}.login-card{width:min(560px,100%);padding:40px}.login-card h1,.hero h1{letter-spacing:-.02em;margin:10px 0;font-size:clamp(32px,5vw,48px);line-height:1.08}.login-card p,.hero p,.user-table span,.user-table small,small{color:var(--muted)}.login-form,.admin-form{gap:10px;margin-top:24px;display:grid}.login-form label{font-weight:700}input,select{border:1px solid var(--line);border-radius:var(--r);background:var(--container-low);min-width:0;padding:13px 14px}input:focus,select:focus{outline:2px solid var(--lime);border-color:var(--lime)}button{border-radius:var(--r);background:var(--primary);color:#fff;border:1px solid #0000;padding:12px 14px;font-weight:800}button:hover{filter:brightness(1.08)}.app-shell{grid-template-columns:280px 1fr;min-height:100vh;display:grid}.sidebar{background:var(--primary);color:#fff;flex-direction:column;gap:22px;height:100vh;padding:24px;display:flex;position:sticky;top:0}.brand b{font-size:24px;display:block}.brand span,.profile-card span{color:var(--cyan)}.profile-card{border-radius:var(--rx);background:var(--primary-2);border:1px solid #234d52;gap:6px;padding:14px;display:grid}.profile-card small{color:var(--cyan)}nav{gap:10px;display:grid}nav button,.logout{text-align:left;background:#ffffff12;border-color:#234d52;width:100%}nav button.active{background:var(--lime);color:var(--primary)}nav button span{display:block}.logout{color:#ffdad6;margin-top:auto}.content{max-width:1280px;padding:24px}.hero{border-radius:var(--rx);color:#fff;border:1px solid #234d52;justify-content:space-between;align-items:end;gap:24px;min-height:260px;padding:36px;display:flex}.hero .eyebrow,.hero p{color:var(--cyan)}.progress-card{border-radius:var(--rx);background:#ffffff14;border:1px solid #234d52;min-width:190px;padding:22px}.progress-card b{color:var(--lime);font-size:48px;display:block}meter{width:100%;accent-color:var(--cyan);margin-top:14px}.player-grid{grid-template-columns:minmax(0,1fr) 360px;gap:24px;margin-top:24px;display:grid}iframe{aspect-ratio:16/9;background:#082a2e;border:0;width:100%}.lesson-meta{justify-content:space-between;align-items:center;gap:18px;padding:22px;display:flex}.lesson-meta h2,.lesson-list h2,.admin-card h2{margin:4px 0}.lesson-meta button,.admin-form button{background:var(--lime);color:var(--primary)}.lesson-list{padding:20px}.lesson-list button{background:var(--container-low);width:100%;color:var(--text);text-align:left;border-color:var(--line);grid-template-columns:42px 1fr 20px;align-items:center;gap:12px;margin-top:10px;display:grid}.lesson-list button.active{background:#d5e3ff}.lesson-list small{display:block}.lesson-list em{color:var(--blue);font-style:normal}.admin-card{margin-top:24px;padding:20px}.admin-form{grid-template-columns:repeat(auto-fit,minmax(140px,1fr))}.user-table{gap:10px;margin:14px 0 24px;display:grid}.user-table>div{border:1px solid var(--line);border-radius:var(--r);background:var(--container-low);grid-template-columns:1.3fr 1.5fr 1fr auto auto;align-items:center;gap:10px;padding:12px;display:grid}.user-table button{background:var(--primary-2);padding:9px 10px}.empty{color:var(--muted);padding:40px}@media (width<=900px){.app-shell,.player-grid,.admin-form,.user-table>div{grid-template-columns:1fr}.sidebar{height:auto;position:static}.hero,.lesson-meta{flex-direction:column;align-items:start}}