:root{color-scheme:light;--blue:#155eef;--ink:#172033;--muted:#667085;--line:#e4e7ec;--bg:#f7f8fa}*{box-sizing:border-box}body,html{margin:0;min-height:100%;background:var(--bg);color:var(--ink);font-family:Inter,ui-sans-serif,system-ui,-apple-system,Segoe UI,sans-serif}a{color:inherit;text-decoration:none}button,input{font:inherit}.shell{width:min(1080px,calc(100% - 32px));margin:0 auto}.topbar{background:#fff;border-bottom:1px solid var(--line)}.topbar-inner{min-height:64px;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{font-weight:750;letter-spacing:-.02em}.nav{display:flex;align-items:center;gap:18px;color:var(--muted);font-size:14px}.page{padding:38px 0 72px}.page-head{display:flex;justify-content:space-between;align-items:flex-start;gap:24px;margin-bottom:24px}h1,h2,h3,p{margin-top:0}h1{font-size:30px;letter-spacing:-.03em;margin-bottom:8px}h2{font-size:20px}.muted{color:var(--muted)}.card{background:#fff;border:1px solid var(--line);border-radius:14px;padding:22px;box-shadow:0 1px 2px rgba(16,24,40,.03)}.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.stack{display:grid;gap:14px}.field{display:grid;gap:7px}.field label{font-size:14px;font-weight:650}input{width:100%;border:1px solid #d0d5dd;border-radius:9px;padding:11px 12px;outline:none;background:#fff}input:focus{border-color:var(--blue);box-shadow:0 0 0 3px rgba(21,94,239,.1)}.button{display:inline-flex;justify-content:center;align-items:center;border:0;border-radius:9px;padding:10px 16px;cursor:pointer;background:var(--blue);color:#fff;font-weight:650}.button.secondary{color:var(--ink);background:#fff;border:1px solid var(--line)}.button:disabled{opacity:.55;cursor:not-allowed}.auth{min-height:100vh;display:grid;place-items:center;padding:24px}.auth-card{width:min(430px,100%)}.error{color:#b42318;background:#fef3f2}.error,.success{padding:10px 12px;border-radius:8px;font-size:14px}.success{color:#067647;background:#ecfdf3}.list-row{display:flex;justify-content:space-between;align-items:center;gap:20px;padding:16px 0;border-top:1px solid var(--line)}.list-row:first-child{border-top:0}.stat{font-size:28px;font-weight:750}.lesson-layout{display:grid;grid-template-columns:260px minmax(0,1fr);gap:20px}.lesson-link{display:block;padding:11px 12px;border-radius:8px;color:var(--muted)}.lesson-link.active{background:#eff4ff;color:#1849a9;font-weight:650}.video-wrap{position:relative;aspect-ratio:16/9;background:#0b0f18;border-radius:12px;overflow:hidden}.video-wrap video{width:100%;height:100%}.watermark{position:absolute;top:7%;right:4%;color:rgba(255,255,255,.58);text-shadow:0 1px 3px #000;font-size:13px;pointer-events:none;animation:wm 17s ease-in-out infinite alternate}@keyframes wm{0%{transform:translate(0)}to{transform:translate(-36vw,26vh)}}.progress{height:8px;overflow:hidden;border-radius:10px;background:#eaecf0}.progress span{display:block;height:100%;background:var(--blue)}@media(max-width:760px){.grid,.lesson-layout{grid-template-columns:1fr}.page-head{display:block}.nav{gap:10px}.shell{width:min(100% - 24px,1080px)}}