@font-face{font-family:Manrope;font-style:normal;font-display:swap;font-weight:200 800;src:url(../assets/fonts/manrope-cyrillic-wght-normal.woff2) format("woff2");unicode-range:U+0301,U+0400-045F,U+0490-0491,U+04B0-04B1,U+2116}
@font-face{font-family:Manrope;font-style:normal;font-display:swap;font-weight:200 800;src:url(../assets/fonts/manrope-latin-wght-normal.woff2) format("woff2");unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}
@font-face{font-family:Unbounded;font-style:normal;font-display:swap;font-weight:600;src:url(../assets/fonts/unbounded-cyrillic-600-normal.woff2) format("woff2");unicode-range:U+0301,U+0400-045F,U+0490-0491,U+04B0-04B1,U+2116}
@font-face{font-family:Unbounded;font-style:normal;font-display:swap;font-weight:600;src:url(../assets/fonts/unbounded-latin-600-normal.woff2) format("woff2");unicode-range:U+0000-00FF,U+2000-206F,U+2122}

:root{
  --bg:#16171d; --surface:#1f2129; --surface-2:#262934; --well:#121318; --line:rgba(255,255,255,.07); --line-2:rgba(255,255,255,.13);
  --text:#f2f4f8; --body:#d5d9e2; --muted:#9aa1b0; --dim:#6d7484;
  --accent:#3d7bff; --accent-hi:#6d9bff; --accent-deep:#2456d6; --accent-soft:rgba(61,123,255,.14); --accent-line:rgba(61,123,255,.45);
  --on-accent:#fff; --code:#9fc0ff; --red:#ff5a6a; --red-soft:rgba(255,90,106,.10); --red-line:rgba(255,90,106,.38);
  --ok:#3fcf8e; --glow-a:rgba(61,123,255,.22); --glow-b:rgba(122,92,255,.12); --pill:rgba(38,41,52,.85); --shadow:rgba(0,0,0,.4);
  --toast-bg:#f2f4f8; --toast-fg:#16171d; --radius:20px; --radius-s:12px;
  --display:Unbounded,"Segoe UI",system-ui,sans-serif; --sans:Manrope,"Segoe UI",system-ui,-apple-system,Roboto,sans-serif;
  --mono:ui-monospace,"SF Mono","Cascadia Mono",Consolas,monospace;
}
:root[data-theme=light]{
  --bg:#f3f5fa; --surface:#ffffff; --surface-2:#ffffff; --well:#eef1f7; --line:rgba(20,30,60,.08); --line-2:rgba(20,30,60,.14);
  --text:#121520; --body:#2f3545; --muted:#5e6678; --dim:#8a91a1;
  --accent:#2f6bff; --accent-hi:#2f6bff; --accent-deep:#1f4fd0; --accent-soft:rgba(47,107,255,.09); --accent-line:rgba(47,107,255,.35);
  --code:#1f4fd0; --red:#e0364a; --red-soft:rgba(224,54,74,.07); --red-line:rgba(224,54,74,.3);
  --glow-a:rgba(47,107,255,.14); --glow-b:rgba(122,92,255,.08); --pill:rgba(255,255,255,.85); --shadow:rgba(20,30,60,.10);
  --toast-bg:#121520; --toast-fg:#fff;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font:400 16px/1.6 var(--sans);-webkit-font-smoothing:antialiased;overflow-x:hidden}
a{color:var(--accent-hi);text-decoration-color:var(--accent-line);text-underline-offset:3px}
b{font-weight:700;color:var(--text)}
.wrap{width:100%;max-width:880px;margin:0 auto;padding:0 16px}
.glow{position:fixed;inset:-20vh -20vw auto;height:80vh;pointer-events:none;z-index:-1;
  background:radial-gradient(40% 50% at 25% 30%,var(--glow-a),transparent 70%),radial-gradient(35% 45% at 80% 15%,var(--glow-b),transparent 70%)}

.top{padding-top:max(18px,env(safe-area-inset-top));padding-bottom:6px}
.brand{display:inline-flex;align-items:center;gap:12px;color:var(--text);text-decoration:none}
.brand img{border-radius:50%;box-shadow:0 4px 16px var(--shadow)}
.brand span{display:flex;flex-direction:column;line-height:1.15}
.brand b{font:600 15px/1.2 var(--display);letter-spacing:.01em}
.brand small{color:var(--muted);font-size:12.5px;margin-top:2px}

.hero{padding:28px 0 22px}
.eyebrow{display:inline-block;font-size:12px;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--accent-hi);
  padding:6px 12px;border:1px solid var(--accent-line);border-radius:99px;background:var(--accent-soft)}
h1{font:600 clamp(28px,7.4vw,48px)/1.12 var(--display);letter-spacing:-.01em;margin:16px 0 12px;text-wrap:balance}
h1 em{font-style:normal;background:linear-gradient(100deg,#5b8cff,#3d7bff 45%,#8b6dff);-webkit-background-clip:text;background-clip:text;color:transparent}
.lead{color:var(--muted);font-size:17px;margin:0;max-width:560px}

.switch{position:relative;display:grid;grid-template-columns:1fr 1fr;padding:5px;margin:4px 0 20px;
  border-radius:999px;background:var(--pill);border:1px solid var(--line);backdrop-filter:blur(16px) saturate(1.4);-webkit-backdrop-filter:blur(16px) saturate(1.4);
  box-shadow:0 8px 24px -12px var(--shadow),inset 0 1px 0 rgba(255,255,255,.04)}
.switch button{position:relative;z-index:1;display:flex;align-items:center;justify-content:center;gap:9px;height:46px;border:0;border-radius:999px;
  background:none;color:var(--muted);font:650 15px var(--sans);letter-spacing:.01em;cursor:pointer;transition:color .3s;-webkit-tap-highlight-color:transparent}
.switch button:hover{color:var(--text)}
.switch button[aria-selected=true]{color:#fff}
.switch svg{width:18px;height:18px;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round;opacity:.9}
.switch-pill{position:absolute;top:5px;bottom:5px;left:5px;width:calc(50% - 5px);border-radius:999px;
  background:linear-gradient(180deg,#4d88ff,#2f66f0);box-shadow:0 6px 16px -6px rgba(47,102,240,.7),inset 0 1px 0 rgba(255,255,255,.22);
  transition:transform .4s cubic-bezier(.32,.72,0,1)}
body[data-device=phone] .switch-pill{transform:translateX(100%)}

.frame{position:relative;margin:0 auto;border-radius:22px;overflow:hidden;background:var(--surface);border:1px solid var(--line-2);
  box-shadow:0 30px 80px -34px rgba(61,123,255,.45),0 0 0 6px var(--line)}
.stage{position:relative;background:#000;overflow:hidden}
.stage video{display:block;width:100%;height:100%;object-fit:contain;cursor:pointer;background:#000}
body[data-device=pc] .stage{aspect-ratio:16/9}
body[data-device=phone] .stage{aspect-ratio:9/16}
body[data-device=phone] .frame{max-width:min(100%,calc((100svh - 230px) * 9 / 16));min-width:min(100%,300px)}

.bigplay{position:absolute;inset:0;margin:auto;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:14px;
  border:0;background:radial-gradient(60% 50% at 50% 55%,rgba(10,14,30,.28),transparent 75%);cursor:pointer;transition:opacity .35s,visibility .35s}
.bp-circle{position:relative;width:84px;height:84px;border-radius:50%;display:grid;place-items:center;
  background:linear-gradient(180deg,#5a91ff,#2f62ea);box-shadow:0 14px 34px -8px rgba(47,98,234,.75),inset 0 1px 0 rgba(255,255,255,.3);
  transition:transform .3s cubic-bezier(.32,.72,0,1)}
.bp-circle::after{content:"";position:absolute;inset:-9px;border-radius:50%;border:1.5px solid rgba(255,255,255,.55);animation:ring 2.4s ease-out infinite}
.bp-circle svg{width:34px;height:34px;fill:#fff;margin-left:4px}
.bigplay:hover .bp-circle{transform:scale(1.06)}
.bigplay:active .bp-circle{transform:scale(.96)}
.bp-label{display:flex;align-items:baseline;gap:8px;padding:8px 16px;border-radius:999px;background:rgba(12,14,24,.62);color:#fff;
  font:700 15px var(--sans);backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px)}
.bp-label small{font-weight:600;font-size:13px;color:rgba(255,255,255,.7);font-variant-numeric:tabular-nums}
.frame.started .bigplay{opacity:0;visibility:hidden}
@keyframes ring{0%{transform:scale(.9);opacity:.9}100%{transform:scale(1.35);opacity:0}}
.spin{position:absolute;left:50%;top:50%;width:44px;height:44px;margin:-22px 0 0 -22px;border-radius:50%;border:3px solid rgba(255,255,255,.25);
  border-top-color:#fff;opacity:0;pointer-events:none;transition:opacity .2s;animation:sp .8s linear infinite}
.frame.loading.started .spin{opacity:1}
@keyframes sp{to{transform:rotate(360deg)}}

.bar{padding:8px 12px 10px;background:var(--surface);border-top:1px solid var(--line)}
.seek{position:relative;height:24px;cursor:pointer;touch-action:none;outline:none}
.track{position:absolute;left:0;right:0;top:50%;height:4px;margin-top:-2px;border-radius:4px;background:var(--line-2);overflow:hidden;transition:height .2s,margin .2s}
.seek:hover .track,.seek.drag .track,.seek:focus-visible .track{height:6px;margin-top:-3px}
.buf,.fill{position:absolute;inset:0;transform-origin:0 50%;transform:scaleX(0)}
.buf{background:var(--line-2)}
.fill{background:linear-gradient(90deg,#3d7bff,#7a8cff)}
.marks i{position:absolute;top:0;bottom:0;width:3px;margin-left:-1.5px;background:var(--surface)}
.knob{position:absolute;top:50%;left:0;width:14px;height:14px;margin:-7px 0 0 -7px;border-radius:50%;background:#fff;
  box-shadow:0 0 0 3px var(--accent),0 2px 8px rgba(0,0,0,.35);transform:scale(0);transition:transform .2s}
.frame.started .knob,.seek:hover .knob,.seek:focus-visible .knob{transform:scale(1)}
.seek.drag .knob{transform:scale(1.25)}
.tip{position:absolute;bottom:calc(100% + 6px);left:0;transform:translateX(-50%);display:flex;flex-direction:column;align-items:center;gap:1px;
  padding:6px 10px;border-radius:10px;background:#0e1018;color:#fff;font:600 12.5px var(--sans);white-space:nowrap;
  box-shadow:0 8px 20px rgba(0,0,0,.35);opacity:0;pointer-events:none;transition:opacity .15s}
.tip b{font-variant-numeric:tabular-nums}
.tip span{color:#a9c1ff;font-weight:600;font-size:12px}
.seek.tipping .tip{opacity:1}

.row{display:flex;align-items:center;gap:2px;margin-top:2px}
.ctl{flex:none;display:grid;place-items:center;min-width:40px;height:40px;padding:0 6px;border:0;border-radius:12px;background:none;color:var(--text);
  cursor:pointer;transition:background .2s;-webkit-tap-highlight-color:transparent}
.ctl:hover{background:var(--surface-2)}
.ctl svg{width:22px;height:22px;fill:currentColor}
.ctl .ln{fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}
.ctl text{font:800 7.2px var(--sans);fill:currentColor}
.pp{width:42px;min-width:42px;height:42px;border-radius:50%;margin-right:4px;color:#fff;background:linear-gradient(180deg,#5a91ff,#2f62ea);
  box-shadow:0 6px 14px -6px rgba(47,98,234,.8)}
.pp:hover{background:linear-gradient(180deg,#6a9cff,#3a6cf2)}
.pp svg{width:20px;height:20px}
.pp .i-play{margin-left:2px}
.frame.playing .pp .i-play,.frame:not(.playing) .pp .i-pause{display:none}
.frame.muted .i-vol,.frame:not(.muted) .i-mute{display:none}
.time{flex:none;margin-left:4px;font:500 13.5px var(--sans);color:var(--muted);font-variant-numeric:tabular-nums}
.time b{color:var(--text);font-weight:700}
.time .sep{margin:0 4px;opacity:.6}
.chap{flex:1;min-width:0;margin:0 8px;overflow:hidden;white-space:nowrap;text-overflow:ellipsis;font:600 13px var(--sans);color:var(--accent-hi)}
.speed{font:700 13px var(--sans);font-variant-numeric:tabular-nums;color:var(--muted)}
@media (max-width:420px){.chap{display:none}.time{flex:1}.bp-circle{width:72px;height:72px}}

.frame:fullscreen{display:flex;flex-direction:column;max-width:none;width:100%;height:100%;border:0;border-radius:0;box-shadow:none;background:#000}
.frame:fullscreen .stage{flex:1;min-height:0;aspect-ratio:auto}
.frame:-webkit-full-screen{display:flex;flex-direction:column;max-width:none;width:100%;height:100%;border:0;border-radius:0;background:#000}
.frame:-webkit-full-screen .stage{flex:1;min-height:0;aspect-ratio:auto}

.chapters{display:flex;gap:8px;overflow-x:auto;padding:14px 2px 4px;scrollbar-width:none;-webkit-overflow-scrolling:touch}
.chapters::-webkit-scrollbar{display:none}
.chapters button{flex:none;display:flex;gap:8px;align-items:baseline;padding:8px 14px;border-radius:10px;border:1px solid transparent;
  background:var(--surface);color:var(--body);font:600 13.5px var(--sans);cursor:pointer;transition:background .2s,border-color .2s,color .2s}
.chapters button span{color:var(--accent-hi);font-variant-numeric:tabular-nums;font-size:12px;font-weight:600;opacity:.8}
.chapters button.on{border-color:var(--accent-line);background:var(--accent-soft);color:var(--text)}
.chapters button.on span{opacity:1}
.chapters button:hover{background:var(--surface-2);color:var(--text)}
.lite{display:block;margin:6px auto 0;padding:8px 10px;background:none;border:0;color:var(--dim);font:500 13px var(--sans);text-decoration:underline;text-underline-offset:3px;cursor:pointer}

h2{font:600 clamp(20px,5vw,26px)/1.25 var(--display);margin:0 0 18px}
.steps{margin-top:44px}
.step{display:grid;grid-template-columns:auto 1fr;gap:16px;padding:22px 20px;margin-bottom:14px;border-radius:var(--radius);
  background:linear-gradient(180deg,var(--surface-2),var(--surface));border:1px solid var(--line)}
.num{width:42px;height:42px;border-radius:50%;display:grid;place-items:center;font:600 17px var(--display);color:#fff;
  background:radial-gradient(circle at 35% 30%,#7ea6ff,var(--accent) 50%,var(--accent-deep));box-shadow:0 8px 20px rgba(61,123,255,.35)}
.step h3{font-size:18.5px;font-weight:700;margin:6px 0 8px;line-height:1.3}
.step p{margin:0 0 10px;color:var(--body)}
.step p:last-child{margin-bottom:0}
.sub{list-style:none;counter-reset:s;padding:0;margin:4px 0 0}
.sub li{counter-increment:s;position:relative;padding-left:30px;margin-bottom:14px}
.sub li::before{content:counter(s);position:absolute;left:0;top:2px;width:20px;height:20px;border-radius:50%;display:grid;place-items:center;
  font-size:11.5px;font-weight:700;color:var(--accent-hi);border:1px solid var(--accent-line)}
.reply{display:inline-grid;place-items:center;min-width:26px;height:26px;padding:0 8px;border-radius:8px;background:var(--accent-soft);border:1px solid var(--accent-line);color:var(--accent-hi);font-weight:800}
code{font-family:var(--mono);font-size:.92em;color:var(--code)}
kbd{font:600 13px var(--mono);padding:2px 7px;border-radius:6px;background:var(--surface-2);border:1px solid var(--line-2);border-bottom-width:2px;color:var(--text)}
.copyline{display:flex;flex-wrap:wrap;align-items:center;gap:8px;padding:8px;margin:2px 0 10px;border-radius:var(--radius-s);background:var(--well);border:1px solid var(--line-2)}
.copyline code{flex:1 1 200px;padding:4px 6px;overflow-wrap:anywhere;font-size:14px}
.btn-copy,.btn-open{flex:none;display:inline-flex;align-items:center;min-height:40px;padding:0 15px;border-radius:10px;font:700 14px var(--sans);cursor:pointer;text-decoration:none}
.btn-copy{border:0;color:#fff;background:linear-gradient(180deg,var(--accent-hi),var(--accent));box-shadow:inset 0 1px 0 rgba(255,255,255,.25)}
.btn-copy.done{background:var(--ok);color:#06210f}
.btn-open{border:1px solid var(--line-2);color:var(--text);background:var(--surface-2)}
.hint{font-size:14.5px;color:var(--muted)!important}
.callout{padding:12px 14px;border-radius:var(--radius-s);font-size:15px;line-height:1.5;color:var(--body)}
.callout.warn{background:var(--red-soft);border:1px solid var(--red-line)}
.callout.key{background:var(--accent-soft);border:1px solid var(--accent-line)}
.safe{display:flex;gap:10px;align-items:center;color:var(--muted);font-size:14.5px;margin:18px 4px 0}
.safe svg{flex:none;width:20px;height:20px;fill:none;stroke:var(--accent-hi);stroke-width:1.8}
body[data-device=pc] .only-phone,body[data-device=phone] .only-pc{display:none}

.help{margin-top:52px}
.help .muted{color:var(--muted);margin:-10px 0 16px}
.help .after{margin:18px 0 0}
.problems{display:grid;gap:10px}
.problem{border-radius:16px;border:1px solid var(--line);background:var(--surface);overflow:hidden;transition:border-color .2s}
.problem.open{border-color:var(--accent-line)}
.problem>button{width:100%;display:flex;align-items:center;gap:12px;padding:16px 16px;min-height:58px;border:0;background:none;color:var(--text);
  font:600 15.5px/1.35 var(--sans);text-align:left;cursor:pointer}
.problem>button .q{flex:none;width:26px;height:26px;border-radius:50%;display:grid;place-items:center;font-size:13px;font-weight:800;color:var(--accent-hi);background:var(--accent-soft)}
.problem>button .t{flex:1}
.problem>button .chev{flex:none;width:18px;height:18px;fill:none;stroke:var(--muted);stroke-width:2;transition:transform .3s}
.problem.open .chev{transform:rotate(180deg)}
.problem .ans{display:grid;grid-template-rows:0fr;transition:grid-template-rows .32s cubic-bezier(.3,.7,.2,1)}
.problem.open .ans{grid-template-rows:1fr}
.problem .ans>div{overflow:hidden}
.problem .ans .in{padding:0 18px 16px 54px;color:var(--body)}
.problem .ans p{margin:0 0 8px}
.problem .ans video{width:100%;border-radius:12px;margin-top:6px;background:#000}

.foot{display:flex;align-items:center;gap:10px;justify-content:center;color:var(--dim);font-size:13px;padding:48px 16px max(28px,env(safe-area-inset-bottom))}
.foot img{border-radius:50%;opacity:.85}

.toast{position:fixed;left:50%;bottom:max(22px,env(safe-area-inset-bottom));transform:translate(-50%,20px);opacity:0;pointer-events:none;
  padding:11px 18px;border-radius:99px;background:var(--toast-bg);color:var(--toast-fg);font:700 14px var(--sans);box-shadow:0 10px 30px var(--shadow);transition:.25s}
.toast.show{opacity:1;transform:translate(-50%,0)}
.theme{width:42px;height:42px;display:grid;place-items:center;border-radius:12px;border:1px solid var(--line-2);background:var(--surface);color:var(--text);cursor:pointer}
.theme svg{width:20px;height:20px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round}
:root[data-theme=light] .i-sun,:root:not([data-theme=light]) .i-moon{display:none}
.top{display:flex;align-items:center;justify-content:space-between}
:root[data-theme=light] .frame{box-shadow:0 30px 60px -30px rgba(47,107,255,.35),0 0 0 6px var(--line)}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}

@media (min-width:720px){
  .hero{padding:44px 0 28px}
  .step{padding:26px 28px;gap:22px}
  .switch{max-width:400px;margin-left:auto;margin-right:auto}
}
@media (prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}

@media (max-width:559px){
  .step{grid-template-columns:36px 1fr;gap:14px 12px;padding:18px 16px}
  .step .body{display:contents}
  .step .body>*:not(h3){grid-column:1/-1}
  .step h3{align-self:center;margin:0;font-size:18px}
  .num{width:36px;height:36px;font-size:15px}
  .sub li{padding-left:28px}
  .copyline code{flex:1 1 100%}
  .btn-copy,.btn-open{flex:1 1 0;justify-content:center;min-height:44px}
  .problem .ans .in{padding:0 16px 16px 16px}
}
@media (min-width:720px){.chapters{flex-wrap:wrap;overflow:visible}}

/* Volume: one capsule on desktop (hover reveals the slider), tap panel on touch screens */
.vol{position:relative;display:flex;align-items:center;border-radius:999px;transition:background .2s}
.vol .mute{border-radius:999px}
.vol:not(.touch):hover,.vol:not(.touch):focus-within,.vol.drag:not(.touch){background:var(--surface-2)}
.vol:not(.touch) .mute:hover{background:none}
.vol-pop{display:flex;align-items:center;width:0;overflow:hidden;opacity:0;transition:width .28s cubic-bezier(.32,.72,0,1),opacity .2s}
.vol:not(.touch):hover .vol-pop,.vol:not(.touch):focus-within .vol-pop,.vol.drag:not(.touch) .vol-pop{width:96px;opacity:1}
.vol-mute{display:none}
.vol-slider{--v:1;--inset:10px;position:relative;flex:none;width:92px;height:36px;margin-left:4px;cursor:pointer;touch-action:none;outline:none}
.vol-track{position:absolute;left:var(--inset);right:var(--inset);top:50%;height:4px;margin-top:-2px;border-radius:4px;background:var(--line-2);overflow:hidden}
.vol-fill{position:absolute;inset:0;transform-origin:0 50%;transform:scaleX(var(--v));background:linear-gradient(90deg,#3d7bff,#7a8cff)}
.vol-knob{position:absolute;top:50%;left:calc(var(--inset) + var(--v) * (100% - 2 * var(--inset)));width:12px;height:12px;margin:-6px 0 0 -6px;
  border-radius:50%;background:#fff;box-shadow:0 0 0 2.5px var(--accent),0 2px 6px rgba(0,0,0,.3);transition:transform .15s}
.vol.drag .vol-knob,.vol-slider:hover .vol-knob,.vol-slider:focus-visible .vol-knob{transform:scale(1.2)}
.frame.vol-low .w2{display:none}

.vol.touch .vol-pop{position:absolute;right:-4px;bottom:calc(100% + 12px);z-index:3;width:auto;overflow:visible;
  padding:6px 8px 6px 6px;gap:2px;border-radius:999px;background:var(--surface-2);border:1px solid var(--line-2);box-shadow:0 14px 34px -10px rgba(0,0,0,.55);
  opacity:0;visibility:hidden;transform:translateY(8px) scale(.97);transform-origin:100% 100%;
  transition:opacity .2s,transform .25s cubic-bezier(.32,.72,0,1),visibility 0s linear .25s}
.vol.touch.open .vol-pop{opacity:1;visibility:visible;transform:none;transition:opacity .2s,transform .25s cubic-bezier(.32,.72,0,1),visibility 0s}
.vol.touch .vol-mute{display:grid;width:44px;height:44px;border-radius:999px}
.vol.touch .vol-slider{--inset:14px;width:164px;height:44px;margin:0}
.vol.touch .vol-track{height:6px;margin-top:-3px}
.vol.touch .vol-knob{width:20px;height:20px;margin:-10px 0 0 -10px}
.vol.touch.open .mute{background:var(--surface-2)}
.vol.no-slider .vol-pop{display:none}