:root{color-scheme:dark;font-family:Inter,"Segoe UI",Arial,sans-serif;--bg:#15191b;--surface:#202629;--line:#394247;--text:#f4f2ed;--muted:#adb8be;--gold:#d9bb8b;--ink:#211c14}*{box-sizing:border-box}body{margin:0;background:radial-gradient(ellipse at 15% 0%,#30302a66,transparent 55%),var(--bg);color:var(--text);min-height:100svh;line-height:1.5}a{color:inherit;text-decoration:none}button{font:inherit;cursor:pointer}a,button{-webkit-tap-highlight-color:transparent}a:focus-visible,button:focus-visible,video:focus-visible{outline:3px solid var(--gold);outline-offset:5px}[hidden]{display:none!important}
.entry-page{display:grid;place-items:center;padding:max(24px,env(safe-area-inset-top)) max(24px,env(safe-area-inset-right)) max(24px,env(safe-area-inset-bottom)) max(24px,env(safe-area-inset-left))}.entry-choices{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px;width:min(680px,100%)}.entry-option{display:flex;flex-direction:column;justify-content:center;align-items:center;gap:24px;min-height:236px;padding:30px;border:1px solid #505047;border-radius:22px;background:linear-gradient(145deg,#30342f,#202629);box-shadow:0 12px 45px #0002;transition:transform .2s,border-color .2s,background .2s}.entry-option svg{width:72px;height:54px;fill:none;stroke:var(--gold);stroke-width:2;stroke-linecap:round;stroke-linejoin:round}.entry-option span{font-size:30px;font-weight:600;letter-spacing:-.03em}.entry-option:hover{transform:translateY(-3px);border-color:var(--gold);background:linear-gradient(145deg,#3d3d32,#252d30)}.entry-option:active{transform:translateY(0)}
.shell{width:min(980px,calc(100% - 64px));margin:auto}.topbar{min-height:88px;display:flex;align-items:center;justify-content:space-between;gap:20px;border-bottom:1px solid #ffffff12}.brand{font-size:21px;font-weight:750;letter-spacing:.12em;display:flex;align-items:center;gap:12px;min-height:44px}.brand-mark{width:31px;height:31px;border:1px solid var(--gold);border-radius:8px;display:grid;place-items:center;color:var(--gold);font-size:18px;letter-spacing:0}.back{color:var(--muted);font-size:14px;display:flex;gap:10px;align-items:center;min-height:44px}.back:hover{color:var(--gold)}.lessons{padding-bottom:40px}.lesson{padding:38px 0 42px;scroll-margin-top:18px}.lesson+.lesson{border-top:1px solid var(--line)}.lesson h2{font-size:clamp(23px,3vw,32px);font-weight:620;line-height:1.25;letter-spacing:-.035em;margin:0 0 22px}.number{color:var(--gold);font-variant-numeric:tabular-nums}.video-frame{position:relative;aspect-ratio:16/9;background:#07090a;border:1px solid var(--line);border-radius:14px;overflow:hidden}.video-frame video{display:block;width:100%;height:100%;object-fit:contain}.video-start{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);display:flex;align-items:center;gap:10px;border:1px solid #f4ddb4;border-radius:99px;padding:13px 23px;background:var(--gold);color:var(--ink);font-weight:650;box-shadow:0 4px 30px #0007;min-height:54px;white-space:nowrap}.video-start svg{width:24px;height:24px;fill:currentColor;stroke:none}.video-start:hover:enabled{background:#edcfa0}.video-start:disabled{cursor:wait;opacity:.85}.video-error{padding:18px;border:1px solid var(--line);border-radius:10px;color:var(--muted)}.video-error a,.not-found a{color:var(--gold);text-decoration:underline;text-underline-offset:3px}.not-found{padding:40px 0}
@media(max-width:600px){.shell{width:calc(100% - 32px)}.topbar{min-height:70px;gap:12px}.brand{font-size:18px;gap:9px}.brand-mark{width:28px;height:28px}.back{font-size:12px}.lesson{padding:28px 0 30px}.lesson h2{margin-bottom:18px}.video-frame{border-radius:10px}.video-start{font-size:14px;min-height:48px;padding:10px 17px}.entry-choices{grid-template-columns:1fr;max-width:360px;gap:18px}.entry-option{min-height:180px;gap:18px;padding:24px}.entry-option svg{width:60px;height:45px}.entry-option span{font-size:28px}}
@media(orientation:landscape) and (max-height:500px){.entry-option{min-height:180px;padding:24px;gap:16px}.entry-choices{grid-template-columns:repeat(2,minmax(0,1fr));max-width:600px}.topbar{min-height:60px}.lesson{padding:24px 0}.lesson h2{font-size:23px;margin-bottom:16px}.video-frame{width:min(100%,calc((100svh - 100px)*16/9));margin-inline:auto}.video-shell{width:min(980px,calc(100% - 48px))}}
@media(prefers-reduced-motion:reduce){.entry-option{transition:none}}