*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,Segoe UI,sans-serif;background:#f6f7f4;color:#17201d;line-height:1.65}a{color:inherit}.w{width:min(1080px,calc(100% - 36px));margin:auto}header{background:#fff;border-bottom:1px solid #dfe5df}.nav{min-height:68px;display:flex;justify-content:space-between;align-items:center;gap:20px}.brand{font-weight:900;text-decoration:none}.nav nav{display:flex;gap:18px;flex-wrap:wrap}.nav nav a{text-decoration:none;color:#5f6d68}.hero{padding:76px 0 44px}.hero h1,.page h1{font-size:clamp(2.3rem,6vw,5rem);line-height:1;letter-spacing:-.04em;max-width:900px}.hero p,.lede{max-width:780px;font-size:1.14rem;color:#5f6d68}.notice{background:#fff4c7;border:1px solid #ead582;padding:14px 18px;border-radius:12px}.grid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px;margin:22px 0 70px}.card{background:#fff;border:1px solid #dfe5df;border-radius:16px;padding:24px;text-decoration:none}.card h3{margin:.4rem 0;font-size:1.35rem}.card p{color:#5f6d68}.page{padding:55px 0 90px;max-width:860px}.calc{background:#fff;border:1px solid #dfe5df;border-radius:16px;padding:22px;display:grid;gap:14px}.field{display:grid;gap:6px}.calc input{width:100%;padding:12px;border:1px solid #dfe5df;border-radius:9px;font:inherit}.calc button{padding:12px 16px;border:0;border-radius:9px;background:#155e75;color:#fff;font-weight:800}.calc output{font-size:1.8rem;font-weight:900}.source-list{padding-left:1.2rem}.muted{color:#5f6d68}.legal{background:#fff;border:1px solid #dfe5df;border-radius:16px;padding:22px}.formula{font-family:ui-monospace,Consolas,monospace;background:#eef2ef;padding:10px;border-radius:8px;overflow:auto}footer{background:#17201d;color:#eef3ef;padding:36px 0;margin-top:60px}footer a{color:#eef3ef}.foot{display:flex;justify-content:space-between;gap:24px;flex-wrap:wrap}@media(max-width:720px){.grid{grid-template-columns:1fr}.nav{align-items:flex-start;padding:16px 0;flex-direction:column}}