/* «Как это работает»: scroll-driven demo. The generator window is the real .composer look (div, not form, so site JS leaves it alone);
   a fake cursor types the prompt, picks a model, presses «Generate», the result appears. Without JS or with reduced motion: final frame, no pin. */
.howto{--ht-top:88px;position:relative}
.ht-pin{display:grid;grid-template-columns:minmax(240px,.78fr) 1.45fr;gap:clamp(28px,4cqi,64px);align-items:center}
.howto.on{height:auto}
.howto.on .ht-pin{position:relative;height:var(--ht-h,680px)}

/* steps */
.ht-steps{list-style:none;margin:0;padding:0;display:grid;gap:8px;counter-reset:none}
.ht-step{position:relative;padding:18px 20px 20px;border-radius:20px;transition:background .3s}
.ht-step .n{display:block;font-size:14px;font-weight:600;color:var(--acc);margin-bottom:6px}
.ht-step h3{font-size:22px;font-weight:600;line-height:1.2;margin:0}
.ht-step p{color:var(--mut);margin:8px 0 0;font-size:15px;line-height:1.45}
.ht-bar{display:block;height:3px;border-radius:3px;background:var(--s3);margin-top:16px;overflow:hidden}
.ht-bar b{display:block;height:100%;width:100%;background:var(--acc);border-radius:inherit;transform-origin:0 50%}
.howto.on .ht-step{opacity:.42;transition:opacity .35s,background .35s}
.howto.on .ht-step.cur{opacity:1;background:var(--s1)}
.howto.on .ht-step.done{opacity:.62}
.howto.on .ht-bar b{transform:scaleX(0)}

/* stage = a piece of the hero: same sky picture, same glass window */
.ht-stage{position:relative;height:100%;min-height:0;border-radius:28px;overflow:hidden;isolation:isolate;display:flex;flex-direction:column;gap:12px;padding:clamp(12px,2cqi,24px);background:#000;color-scheme:dark;
  --bg:#000;--s1:#0e0e10;--s2:#1c1c1e;--s3:#2c2c2e;--line:#2c2c2e;--fg:#f5f5f7;--mut:#a1a1a6;color:var(--fg);-webkit-user-select:none;user-select:none}
.howto:not(.on) .ht-stage{aspect-ratio:4/3;height:auto}
.ht-bg{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;z-index:-2}
.ht-stage::after{content:"";position:absolute;inset:0;z-index:-1;background:linear-gradient(180deg,rgba(0,0,0,.25),rgba(0,0,0,.55))}
.ht-bg.l{display:none}
html[data-theme=light] .ht-bg.d{display:none}
html[data-theme=light] .ht-bg.l{display:block}
html[data-theme=light] .ht-stage{background:#fff;color-scheme:light;--bg:#fff;--s1:#f5f5f7;--s2:#e8e8ed;--s3:#d2d2d7;--line:#e3e3e8;--fg:#1d1d1f;--mut:#6e6e73}
html[data-theme=light] .ht-stage::after{background:linear-gradient(180deg,rgba(255,255,255,.2),rgba(255,255,255,.45))}

/* output tile */
.ht-out{position:relative;flex:1 1 auto;min-height:96px;display:flex;justify-content:center}
.ht-res{position:relative;margin:0;height:100%;aspect-ratio:16/9;max-width:100%;border-radius:18px;overflow:hidden;background:rgba(28,28,30,.55);border:1px solid rgba(255,255,255,.12);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px)}
html[data-theme=light] .ht-res{background:rgba(255,255,255,.55);border-color:rgba(0,0,0,.08)}
.ht-res img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;object-position:50% 40%}
.ht-empty{position:absolute;inset:0;display:grid;place-items:center;color:var(--mut)}
.ht-empty .ico{width:28px;height:28px;stroke-width:1.5;opacity:.7}
.ht-load{position:absolute;inset:0;display:grid;place-items:center;align-content:center;gap:10px;color:#fff;font-size:13px;font-weight:600;font-variant-numeric:tabular-nums;background:linear-gradient(100deg,transparent 30%,rgba(255,255,255,.14) 50%,transparent 70%) 0 0/250% 100%;animation:ht-sh 1.4s linear infinite}
.ht-load i{display:block;width:min(160px,50%);height:3px;border-radius:3px;background:rgba(255,255,255,.22);overflow:hidden}
.ht-load b{display:block;height:100%;background:#fff;transform-origin:0 50%}
@keyframes ht-sh{to{background-position:-250% 0}}
.ht-meta{position:absolute;left:10px;right:10px;bottom:10px;display:flex;align-items:center;justify-content:space-between;gap:8px}
.ht-meta .pill .ico{width:13px;height:13px;stroke-width:1.5;color:#7cc0ff}
.ht-dl{display:grid;place-items:center;width:36px;height:36px;border-radius:50%;background:rgba(0,0,0,.6);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);color:#fff;transition:background .2s,transform .2s}
.ht-dl .ico{width:18px;height:18px;stroke-width:1.6}
.ht-dl.hov{background:#fff;color:#000}

/* window: real .composer look, plus a typed line and a model menu */
.ht-stage .composer{position:relative;flex:none;max-width:none;margin:0}
.ht-text{min-height:76px;padding:10px 14px;font-size:16px;line-height:1.45;color:var(--fg);overflow-wrap:anywhere}
.ht-ph{color:#8e8e93}
.ht-caret{display:inline-block;width:2px;height:1.15em;margin-left:1px;vertical-align:-.2em;background:var(--acc);border-radius:1px;animation:ht-bl 1s steps(1) infinite}
@keyframes ht-bl{50%{opacity:0}}
.ht-stage .c-bar{position:relative}
.ht-stage .c-bar .chip{cursor:default;transition:background .2s,border-color .2s}
.ht-stage .c-bar .chip.hov{background:rgba(255,255,255,.1)}
html[data-theme=light] .ht-stage .c-bar .chip.hov{background:rgba(0,0,0,.06)}
.ht-stage .c-go .btn{cursor:default;transition:transform .15s,background .15s}
.ht-stage .c-go .btn.hov{background:var(--acc-btn-h,#0a7cf0)}
.ht-stage .c-go .btn.down{transform:scale(.95)}
.ht-cost{font-variant-numeric:tabular-nums}
.ht-menu{position:absolute;left:4px;bottom:calc(100% + 6px);z-index:3;min-width:220px;padding:6px;border-radius:16px;background:rgba(28,28,30,.92);border:1px solid rgba(255,255,255,.12);-webkit-backdrop-filter:blur(24px);backdrop-filter:blur(24px);box-shadow:0 18px 40px rgba(0,0,0,.4);opacity:0;transform:translateY(6px) scale(.97);transform-origin:0 100%;pointer-events:none}
html[data-theme=light] .ht-menu{background:rgba(255,255,255,.95);border-color:rgba(0,0,0,.08);box-shadow:0 18px 40px rgba(0,0,0,.14)}
.ht-menu.measure{transform:none}
.ht-row{display:flex;align-items:center;gap:10px;min-height:38px;padding:0 10px;border-radius:10px;font-size:14px;white-space:nowrap}
.ht-row .nm{flex:1}
.ht-row .cs{display:inline-flex;align-items:center;gap:4px;color:var(--mut);font-size:13px;font-variant-numeric:tabular-nums}
.ht-row .cs .ico{width:14px;height:14px}
.ht-row .ck{width:16px;height:16px;color:var(--acc);opacity:0}
.ht-row.sel .ck{opacity:1}
.ht-row.hov{background:rgba(255,255,255,.1)}
html[data-theme=light] .ht-row.hov{background:rgba(0,0,0,.06)}

/* cursor: the pointer shape is drawn, not an icon */
.ht-cur{position:absolute;left:0;top:0;z-index:5;width:22px;height:22px;pointer-events:none;opacity:0;will-change:transform;filter:drop-shadow(0 2px 4px rgba(0,0,0,.45))}
.ht-cur svg{display:block;width:22px;height:22px;transition:transform .12s}
.ht-cur.down svg{transform:scale(.86)}
.ht-cur i{position:absolute;left:-14px;top:-14px;width:28px;height:28px;border-radius:50%;background:rgba(255,255,255,.55);opacity:0;transform:scale(.3)}
.howto:not(.on) .ht-cur,.howto:not(.on) .ht-caret,.howto:not(.on) .ht-load,.howto:not(.on) .ht-empty{display:none}

/* phones and narrow windows: window on top, one step caption under it */
@container site (max-width:900px){
  .ht-pin{grid-template-columns:1fr;grid-template-rows:auto;gap:16px}
  .howto.on .ht-pin{grid-template-rows:auto 1fr;gap:12px;align-items:stretch;min-height:0;max-height:none}
  .ht-stage{border-radius:24px;padding:10px;gap:10px}
  .howto.on .ht-stage{min-height:0}
  .ht-text{min-height:56px;font-size:15px;padding:8px 12px}
  .ht-res{width:100%;aspect-ratio:auto;border-radius:16px}
  .howto:not(.on) .ht-res{aspect-ratio:16/10;height:auto}
  .howto:not(.on) .ht-stage{aspect-ratio:auto}
  .ht-menu{min-width:0;width:min(250px,calc(100% - 8px))}
  /* one caption, crossfades */
  .howto.on .ht-steps{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:6px;align-content:start}
  .howto.on .ht-step{grid-row:2;grid-column:1/-1;padding:0 2px;background:none!important;opacity:0;transform:translateY(6px);transition:opacity .3s,transform .3s}
  .howto.on .ht-step:not(.cur){opacity:0}
  .howto.on .ht-step.cur{opacity:1;transform:none}
  .howto.on .ht-step .ht-bar{display:none}
  .howto.on .ht-step h3{font-size:19px}
  .howto.on .ht-step p{font-size:14px;margin-top:4px}
  .howto.on .ht-step .n{font-size:13px;margin-bottom:4px}
  .ht-dots{display:none}
  .howto.on .ht-dots{display:contents}
  .ht-dots i{grid-row:1;height:3px;border-radius:3px;background:var(--s3);overflow:hidden;margin-bottom:10px}
  .ht-dots b{display:block;height:100%;background:var(--acc);transform-origin:0 50%;transform:scaleX(0)}
  .ht-step{padding:16px 2px 4px}
}
@container site (min-width:901px){.ht-dots{display:none}}
@media (max-height:620px){.howto{--ht-top:76px}.ht-step p{display:none}}

.howto:not(.on) .ht-bar{display:none}
@container site (max-width:360px){.ht-stage .c-bar>.chip:not(.ht-model){display:none}}
.howto.on.fin .ht-cur{display:none}
.ht-stage{background:none!important;padding:0!important;border-radius:0;overflow:visible}
.ht-stage::after{display:none}
.ht-res{background:var(--s1);border-color:var(--line);-webkit-backdrop-filter:none;backdrop-filter:none}
html[data-theme=light] .ht-res{background:var(--s1);border-color:var(--line)}
.ht-stage .composer{background:var(--s1);border-color:var(--line);-webkit-backdrop-filter:none;backdrop-filter:none}
/* empty result: a living «something is coming» surface instead of a blank box (dot texture, drifting glow, light sweep) */
.ht-empty{overflow:hidden;background:radial-gradient(circle,rgba(255,255,255,.09) 1px,transparent 1.3px) 0 0/16px 16px}
html[data-theme=light] .ht-empty{background-image:radial-gradient(circle,rgba(0,0,0,.09) 1px,transparent 1.3px)}
.ht-empty::before,.ht-empty::after{content:"";position:absolute;width:80%;height:80%;border-radius:50%;pointer-events:none;will-change:transform}
.ht-empty::before{left:-10%;top:-15%;background:radial-gradient(closest-side,rgba(41,151,255,.32),transparent);animation:ht-drift1 7s ease-in-out infinite alternate}
.ht-empty::after{right:-15%;bottom:-20%;background:radial-gradient(closest-side,rgba(122,92,255,.28),transparent);animation:ht-drift2 8s ease-in-out infinite alternate}
html[data-theme=light] .ht-empty::before{background:radial-gradient(closest-side,rgba(0,113,227,.18),transparent)}
html[data-theme=light] .ht-empty::after{background:radial-gradient(closest-side,rgba(122,92,255,.16),transparent)}
@keyframes ht-drift1{to{transform:translate(35%,40%) scale(1.15)}}
@keyframes ht-drift2{to{transform:translate(-40%,-35%) scale(1.1)}}
.ht-empty .ico{position:relative;z-index:1;animation:ht-pulse 2.4s ease-in-out infinite}
@keyframes ht-pulse{50%{opacity:.25;transform:scale(.92)}}
.ht-sweep{position:absolute;inset:0;background:linear-gradient(100deg,transparent 35%,rgba(255,255,255,.08) 50%,transparent 65%) 0 0/250% 100%;animation:ht-sh 2.6s linear infinite}
html[data-theme=light] .ht-sweep{background-image:linear-gradient(100deg,transparent 35%,rgba(255,255,255,.7) 50%,transparent 65%)}
/* model list: fully opaque (WebKit showed the prompt text through it) */
.ht-menu{background:#1c1c1e;-webkit-backdrop-filter:none;backdrop-filter:none}
html[data-theme=light] .ht-menu{background:#fff}
.howto.fin .ht-load{display:none!important}
@container site (min-width:901px){.ht-text{min-height:52px}.ht-step{padding:14px 18px 16px}.ht-step h3{font-size:20px}.ht-bar{margin-top:12px}}
@container site (min-width:901px){.ht-res{width:100%;aspect-ratio:auto}}
@container site (min-width:901px){.ht-res img{object-position:50% 22%}}