:root{--a:#1f6f78;--ink:#1d2327;--muted:#5f6b72;--bg:#fbfaf7;--card:#fff;--line:#e3e0d8}
*{box-sizing:border-box}body{margin:0;font:17px/1.65 system-ui,-apple-system,Segoe UI,Roboto,sans-serif;color:var(--ink);background:var(--bg)}
a{color:var(--a)}header,footer{background:#fff;border-bottom:1px solid var(--line)}footer{border-top:1px solid var(--line);border-bottom:0;margin-top:3rem;font-size:.9rem;color:var(--muted)}
.wrap{max-width:860px;margin:0 auto;padding:1rem 1.25rem}nav a{margin-right:1rem;text-decoration:none;font-weight:600}
.brand{font-weight:800;font-size:1.2rem;text-decoration:none;color:var(--ink);margin-right:1.5rem}
h1{line-height:1.2;font-size:2rem}h2{margin-top:2rem}blockquote{margin:1rem 0;padding:.75rem 1rem;background:#eef6f6;border-left:4px solid var(--a)}
table{border-collapse:collapse;width:100%;margin:1rem 0}td,th{border:1px solid var(--line);padding:.4rem .6rem;text-align:left}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:1rem}.card{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:1rem}
.card h3{margin-top:0}.mt{margin-top:1rem}.muted{color:var(--muted);font-size:.92rem}.notice{background:#fff7e6;border:1px solid #f0d9a8;padding:.75rem 1rem;border-radius:8px;font-size:.95rem}
form.calc{display:grid;gap:.6rem}form.calc label{display:grid;grid-template-columns:1fr 160px;gap:.75rem;align-items:center}
input{font:inherit;padding:.4rem .5rem;border:1px solid #c9c4b8;border-radius:6px;width:100%}.results{background:#eef6f6;border-radius:10px;padding:1rem;margin-top:1rem}
.results dl{display:grid;grid-template-columns:1fr auto;gap:.3rem 1rem;margin:0}.results dd{margin:0;font-weight:700;text-align:right}.error{color:#b00020}
.btn{display:inline-block;background:var(--a);color:#fff;padding:.55rem 1rem;border-radius:8px;text-decoration:none;font-weight:700}
.pay{display:grid;grid-template-columns:200px 1fr;gap:1rem;align-items:start}.pay svg{width:200px;height:200px;background:#fff}.btc-slot[hidden]{display:none}
code{background:#f1efe9;padding:.1rem .3rem;border-radius:4px;word-break:break-all}
@media(max-width:600px){form.calc label{grid-template-columns:1fr}.pay{grid-template-columns:1fr}}