:root{color-scheme:dark;--bg:#09090b;--panel:#121215;--line:#3f3f46;--text:#f4f4f5;--muted:#c4c4cf;--blue:#38bdf8;--green:#4ade80}*{box-sizing:border-box}body{margin:0;padding:2rem 1rem;background:var(--bg);color:var(--text);font:16px/1.6 system-ui,sans-serif}main{max-width:1020px;margin:auto}a{color:#7dd3fc}h1{font-size:clamp(1.8rem,5vw,2.5rem);line-height:1.18}h2{color:var(--blue);font-size:1.35rem}h3{font-size:1.1rem}.muted,small{color:var(--muted)}.back{display:inline-block;margin-bottom:1rem}.card{border:1px solid var(--line);border-radius:16px;background:var(--panel);padding:clamp(1rem,4vw,2rem);margin:1rem 0}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,230px),1fr));gap:1rem}.grid>div{min-width:0}label{display:block;font-weight:650;margin-bottom:.4rem}input,select{font:inherit;width:100%;padding:.65rem;border-radius:9px;border:1px solid #71717a;background:#18181b;color:white}button{font:inherit;padding:.7rem 1.2rem;border:0;border-radius:9px;background:var(--blue);color:#09090b;font-weight:750;cursor:pointer;margin-top:1rem}input:focus-visible,select:focus-visible,button:focus-visible,a:focus-visible{outline:2px solid var(--blue);outline-offset:2px}.result{font-weight:750;font-size:clamp(1.2rem,4vw,1.7rem);color:var(--green);margin:.25rem 0 1rem}.details{color:var(--muted)}summary{cursor:pointer;font-weight:700}footer{max-width:1020px;margin:2rem auto;border-top:1px solid var(--line);padding-top:1.3rem;display:flex;gap:1rem;flex-wrap:wrap}@media(max-width:600px){body{padding:1rem}.card{margin:.7rem 0}}