:root{color-scheme:light dark;--bg:#f7f6fc;--surface:#fff;--ink:#19162f;--secondary:#59556e;--line:#dcd8ea;--accent:#5d55e8;--danger:#ae2643}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:17px/1.6 system-ui,sans-serif}header,footer{max-width:760px;margin:auto;padding:24px;display:flex;align-items:center;justify-content:space-between;gap:24px}a{color:var(--accent);text-underline-offset:4px}.brand{display:flex;gap:10px;align-items:center;font-weight:700;color:var(--ink);text-decoration:none}main{max-width:712px;margin:36px auto 64px;padding:0 24px}h1{font-size:clamp(32px,5vw,44px);line-height:1.15;letter-spacing:-1px;margin:12px 0}h2{font-size:23px;line-height:1.3;margin:0 0 14px}p{margin:0 0 16px}.intro{font-size:21px;color:var(--secondary)}.eyebrow{color:var(--accent);font-size:14px;font-weight:650}section{margin-top:36px}.card{padding:28px;border:1px solid var(--line);border-radius:24px;background:var(--surface)}label{display:block;font-weight:600;margin-top:20px}input[type=text]{width:100%;min-height:52px;font:16px/1.5 ui-monospace,monospace;background:var(--bg);color:var(--ink);border:1px solid var(--line);border-radius:12px;padding:12px}input:focus-visible,button:focus-visible,a:focus-visible{outline:3px solid var(--accent);outline-offset:4px}.hint{font-size:14px;color:var(--secondary);margin-top:8px}.check{display:flex;gap:12px;font-weight:400;align-items:flex-start}.check input{width:22px;height:22px;flex-shrink:0;margin-top:3px;accent-color:var(--danger)}button{width:100%;min-height:52px;padding:12px 16px;margin-top:24px;background:var(--danger);color:#fff;border:0;border-radius:12px;font:600 16px/1.5 system-ui,sans-serif;cursor:pointer}button:disabled{opacity:.6;cursor:wait}#result{margin:16px 0 0}#result[data-error=true]{color:var(--danger)}footer{font-size:14px;color:var(--secondary);border-top:1px solid var(--line)}nav{display:flex;gap:16px}@media(prefers-color-scheme:dark){:root{--bg:#100f1a;--surface:#1c192d;--ink:#f3f0ff;--secondary:#b7b0cf;--line:#3b354e;--accent:#b0a8ff;--danger:#c9395a}}@media(max-width:480px){.card{padding:20px}footer{align-items:flex-start;flex-direction:column}}