:root{color-scheme:dark;font-family:Inter,system-ui,sans-serif;--bg:#09090b;--panel:#151519;--line:#303038;--text:#f4f1ed;--muted:#aaa5a1;--red:#e31d36;--green:#66d49c}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);line-height:1.55}header,main,footer{max-width:1000px;margin:auto;padding:24px}header{display:flex;justify-content:space-between;gap:20px;border-bottom:1px solid var(--line)}a{color:inherit}.brand{text-decoration:none;font-weight:750}.brand strong{letter-spacing:.1em}.lang{display:flex;gap:14px}.eyebrow{color:var(--red);font-size:.75rem;text-transform:uppercase;letter-spacing:.14em}h1{font-size:clamp(2.4rem,7vw,5.6rem);line-height:.94;letter-spacing:-.055em;margin:64px 0 26px;overflow-wrap:anywhere}.lead{font-size:1.2rem;color:var(--muted);max-width:760px}.grid{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin:50px 0}.panel{background:var(--panel);border:1px solid var(--line);padding:24px}.panel h2{margin-top:0}.fields{list-style:none;padding:0}.fields li{display:grid;grid-template-columns:1fr auto;gap:16px;padding:12px 0;border-bottom:1px solid var(--line)}code,textarea{font-family:ui-monospace,SFMono-Regular,Consolas,monospace}textarea{width:100%;min-height:280px;background:#0d0d10;color:var(--text);border:1px solid var(--line);padding:16px;resize:vertical}button{margin-top:14px;background:var(--red);border:0;color:white;font:inherit;font-weight:700;padding:12px 18px;cursor:pointer}.result{border-left:3px solid var(--line);padding:12px;margin-top:16px}.result.valid{border-color:var(--green)}.result.invalid{border-color:var(--red)}footer{border-top:1px solid var(--line);color:var(--muted);margin-top:50px}@media(max-width:700px){header,main,footer{padding:20px}.grid{grid-template-columns:1fr}h1{margin-top:44px;font-size:clamp(2.2rem,13vw,4rem)}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}}