:root{--bg:#f4f6f9;--surface:#fff;--text:#172033;--muted:#667085;--primary:#2557d6;--danger:#c93636;--success:#16794b;--border:#dfe4ec;--shadow:0 8px 24px rgba(20,34,66,.08)}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-family:Inter,system-ui,-apple-system,"Segoe UI",sans-serif;line-height:1.5}a{color:var(--primary);text-decoration:none}.topbar{position:sticky;top:0;z-index:10;display:flex;align-items:center;justify-content:space-between;gap:20px;padding:14px max(20px,calc((100% - 1180px)/2));background:#111a2c;color:#fff;box-shadow:0 4px 14px rgba(0,0,0,.16)}.topbar a{color:#fff}.brand{font-weight:800;font-size:18px}.brand-mark{display:inline-grid;place-items:center;width:30px;height:30px;border-radius:9px;background:#3f73ff;margin-right:7px}.topbar nav{display:flex;gap:16px;align-items:center;flex-wrap:wrap}.container{width:min(1180px,calc(100% - 32px));margin:28px auto 60px}.footer{text-align:center;color:var(--muted);padding:24px}.grid{display:grid;gap:20px}.grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}.grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}.card{background:var(--surface);border:1px solid var(--border);border-radius:16px;padding:22px;box-shadow:var(--shadow)}.card h1,.card h2,.card h3{margin-top:0}.stat{font-size:34px;font-weight:800}.muted{color:var(--muted)}.actions{display:flex;gap:8px;align-items:center;flex-wrap:wrap}.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border:0;border-radius:10px;background:var(--primary);color:#fff;padding:10px 15px;font-weight:700;cursor:pointer}.btn:hover{filter:brightness(.95)}.btn-secondary{background:#e9edf5;color:#1d2b45}.btn-danger{background:var(--danger)}.btn-success{background:var(--success)}.btn-small{padding:7px 10px;font-size:13px}.btn-block{width:100%}form.inline{display:inline}label{display:block;font-weight:700;margin-bottom:6px}input,textarea,select{width:100%;padding:11px 12px;border:1px solid #cbd3df;border-radius:10px;background:#fff;color:var(--text);font:inherit}textarea{min-height:110px;resize:vertical}.form-group{margin-bottom:16px}.help{font-size:13px;color:var(--muted);margin-top:5px}.table-wrap{overflow:auto}.table{width:100%;border-collapse:collapse}.table th,.table td{padding:12px 10px;border-bottom:1px solid var(--border);text-align:left;vertical-align:top}.table th{font-size:13px;color:var(--muted);text-transform:uppercase;letter-spacing:.04em}.badge{display:inline-block;padding:4px 9px;border-radius:999px;background:#e8eefc;color:#23458f;font-size:12px;font-weight:800}.badge-success{background:#dff5e9;color:#11623c}.badge-warning{background:#fff3d6;color:#7b5500}.badge-danger{background:#fde5e5;color:#9c2727}.alert{padding:13px 16px;border-radius:11px;margin-bottom:16px;border:1px solid transparent}.alert-success{background:#e5f7ed;border-color:#bce8cf;color:#125d39}.alert-danger{background:#fdeaea;border-color:#f3c2c2;color:#922d2d}.alert-warning{background:#fff5d9;border-color:#f0dfaa;color:#745400}.alert-info{background:#e8f1ff;border-color:#c5d8fb;color:#244f91}.login-shell{min-height:70vh;display:grid;place-items:center}.login-card{width:min(460px,100%)}.course-card{padding:0;overflow:hidden}.course-cover{width:100%;height:180px;object-fit:cover;background:#dfe7f6}.course-placeholder{height:180px;display:grid;place-items:center;background:linear-gradient(135deg,#1f4bc3,#6d8fff);color:#fff;font-size:48px}.course-body{padding:20px}.progress{height:10px;border-radius:999px;background:#e4e8ef;overflow:hidden}.progress span{display:block;height:100%;background:var(--primary)}.module{border:1px solid var(--border);border-radius:14px;margin-bottom:14px;overflow:hidden;background:#fff}.module-title{padding:15px 17px;background:#eef2f8;font-weight:800}.lesson-row{display:flex;justify-content:space-between;gap:15px;align-items:center;padding:13px 17px;border-top:1px solid var(--border)}.lesson-row:first-of-type{border-top:0}.lesson-state{width:28px;height:28px;display:grid;place-items:center;border-radius:50%;background:#e7ebf3;color:#65738b;font-weight:800;flex:none}.lesson-state.done{background:#d8f2e4;color:#137348}.video-wrap{position:relative;padding-top:56.25%;border-radius:14px;overflow:hidden;background:#000}.video-wrap iframe,.video-wrap video{position:absolute;inset:0;width:100%;height:100%;border:0}.pdf-frame{width:100%;height:70vh;border:1px solid var(--border);border-radius:12px}.section-title{display:flex;justify-content:space-between;gap:16px;align-items:center;margin-bottom:18px}.empty{text-align:center;padding:40px 20px;color:var(--muted)}.cover-small{width:74px;height:48px;object-fit:cover;border-radius:8px;background:#e6ebf3}.notice{padding:14px;border-left:4px solid var(--primary);background:#eef4ff;border-radius:8px}.danger-zone{border-color:#f1c4c4;background:#fffafa}@media(max-width:780px){.topbar{position:static;align-items:flex-start;flex-direction:column}.topbar nav{gap:10px}.grid-2,.grid-3{grid-template-columns:1fr}.container{width:min(100% - 20px,1180px);margin-top:18px}.card{padding:17px}.section-title{align-items:flex-start;flex-direction:column}.lesson-row{align-items:flex-start}.table{min-width:680px}}