:root{--bg:#f3f6fb;--card:#fff;--ink:#0f1b2d;--mute:#53627a;--line:#d9e1ee;--pri:#2457d6;--pri-ink:#fff;--ok:#0d7c66;--band:#e9eef7}
@media (prefers-color-scheme:dark){:root{--bg:#0d1422;--card:#16203a;--ink:#eef2fa;--mute:#9db0cf;--line:#2a3858;--pri:#5b8cff;--pri-ink:#0d1422;--ok:#3ec9a7;--band:#111b30}}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.6 system-ui,-apple-system,"Segoe UI",Roboto,"Noto Sans",sans-serif;-webkit-text-size-adjust:100%}
a{color:var(--pri)}
:focus-visible{outline:3px solid var(--pri);outline-offset:2px}
.top{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:14px max(16px,calc((100% - 1040px)/2));border-bottom:1px solid var(--line);background:var(--card)}
.brand{font-weight:800;font-size:1.15rem;letter-spacing:-.02em;color:var(--ink);text-decoration:none}
.brand span{color:var(--pri)}
.top nav a{margin-left:18px;color:var(--mute);text-decoration:none;font-weight:600}
.top nav a:hover{color:var(--ink)}
main>section{padding:36px max(16px,calc((100% - 1040px)/2))}
.hero{padding-top:40px}
h1{font-size:clamp(1.9rem,5.4vw,3.2rem);line-height:1.1;letter-spacing:-.03em;margin:0 0 12px;max-width:18ch}
h2{font-size:1.5rem;letter-spacing:-.02em;margin:0 0 16px}
h3{margin:0 0 6px;font-size:1.05rem}
.lead{color:var(--mute);font-size:1.1rem;max-width:56ch;margin:0 0 24px}
.tool{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:16px;max-width:860px}
.drop{display:flex;flex-direction:column;align-items:center;gap:4px;text-align:center;padding:36px 16px;border:2px dashed var(--line);border-radius:10px;cursor:pointer}
.drop strong{font-size:1.15rem}
.drop span{color:var(--mute);font-size:.92rem}
.drop input{position:absolute;opacity:0;width:1px;height:1px}
.drop.over,.drop:hover{border-color:var(--pri);background:var(--band)}
.panel{margin-top:16px}
.previews{display:grid;grid-template-columns:1fr;gap:12px;margin-bottom:16px}
figure{margin:0;border:1px solid var(--line);border-radius:10px;overflow:hidden;background:var(--band)}
figure img{display:block;width:100%;max-height:260px;object-fit:contain;background:var(--band)}
figcaption{padding:8px 12px;font-size:.88rem;color:var(--mute);border-top:1px solid var(--line);background:var(--card)}
.grid{display:grid;grid-template-columns:1fr 1fr;gap:12px}
label{display:flex;flex-direction:column;gap:4px;font-size:.9rem;font-weight:600}
input[type=number],select{font:inherit;padding:10px 12px;border:1px solid var(--line);border-radius:8px;background:var(--bg);color:var(--ink);width:100%}
.check{flex-direction:row;align-items:center;gap:8px;margin:14px 0 8px;font-weight:500}
.presets{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:14px}
.presets button{font:inherit;font-weight:600;padding:8px 14px;border:1px solid var(--line);border-radius:999px;background:var(--card);color:var(--ink);cursor:pointer}
.presets button:hover{border-color:var(--pri)}
.range{font-weight:600}
.range output{float:right;color:var(--mute);font-weight:500}
input[type=range]{width:100%;accent-color:var(--pri)}
.actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:16px}
.go,.dl{font:inherit;font-weight:700;padding:13px 22px;border-radius:10px;border:0;cursor:pointer;text-decoration:none;text-align:center;flex:1 1 180px}
.go{background:var(--pri);color:var(--pri-ink)}
.dl{background:var(--ok);color:#fff}
.go:disabled{opacity:.6;cursor:wait}
.msg{min-height:1.5em;margin:12px 0 0;font-size:.92rem;color:var(--mute)}
.msg.err{color:#c0392b}
.note{color:var(--mute);font-size:.9rem;margin:12px 0 0}
.band{background:var(--card);border-block:1px solid var(--line)}
.band.alt{background:var(--band)}
.steps{margin:0;padding-left:1.2em;max-width:62ch}
.steps li{margin-bottom:8px}
.three{display:grid;grid-template-columns:1fr;gap:20px}
.three p{margin:0;color:var(--mute)}
details{border-bottom:1px solid var(--line);padding:12px 0;max-width:70ch}
summary{font-weight:700;cursor:pointer}
details p{color:var(--mute);margin:8px 0 0}
footer{padding:24px max(16px,calc((100% - 1040px)/2));color:var(--mute);font-size:.9rem}
footer p{margin:0}
@media (min-width:720px){
  .previews{grid-template-columns:1fr 1fr}
  .grid{grid-template-columns:repeat(4,1fr)}
  .three{grid-template-columns:repeat(3,1fr)}
  .tool{padding:24px}
}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

.hero{text-align:center;padding-top:48px}
h1{max-width:20ch;margin-inline:auto}
.lead{margin-inline:auto}
.tool{max-width:980px;margin-inline:auto;text-align:left}
.note{text-align:center}
figure img{height:240px;max-height:none}
.sizes{margin:12px 0 4px}
.sizes button{background:var(--band)}
.hint{font-size:.85rem;color:var(--mute);margin:0 0 6px}
.brand{display:flex;align-items:center;gap:10px}
.brand span{color:var(--ink)}
.top nav{display:flex;flex-wrap:wrap}
.pick{display:inline-block;background:var(--pri);color:var(--pri-ink);font-weight:700;padding:13px 28px;border-radius:10px;font-size:1.05rem;margin-bottom:8px}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(210px,1fr));gap:12px}
.card{display:flex;flex-direction:column;gap:2px;padding:14px 16px;border:1px solid var(--line);border-radius:10px;background:var(--card);color:var(--ink);text-decoration:none}
.card:hover{border-color:var(--pri)}
.card span{color:var(--mute);font-size:.9rem}
.modes{margin-bottom:12px}
.presets button.on{background:var(--pri);color:var(--pri-ink);border-color:var(--pri)}
.spec{border-collapse:collapse;width:100%;max-width:640px;margin:0 0 12px}
.spec th,.spec td{border:1px solid var(--line);padding:8px 12px;text-align:left}
.prose{max-width:none}
.prose>*{max-width:70ch}
.prose p{color:var(--mute)}
.prose h1{margin-inline:0}
.foot{display:flex;flex-wrap:wrap;gap:8px 20px;margin-bottom:10px}
.foot a{color:var(--mute)}