:root {
  --bg: #f7f8fa; --card: #ffffff; --text: #14181f; --muted: #5b6472;
  --accent: #1f6feb; --accent-ink: #ffffff; --line: #e3e7ee; --ok: #1a7f37;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0f1216; --card: #171b21; --text: #eef1f5; --muted: #9aa4b2;
          --accent: #4c8dff; --accent-ink: #ffffff; --line: #262c35; --ok: #3fb950; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text);
       font: 16px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; }
.wrap { max-width: 1040px; margin: 0 auto; padding: 0 20px; }
header { padding: 20px 0; display: flex; justify-content: space-between; align-items: center; }
header a { color: var(--text); text-decoration: none; font-weight: 600; }
.hero { padding: 56px 0 40px; text-align: center; }
.hero h1 { font-size: clamp(32px, 6vw, 54px); line-height: 1.1; margin: 0 0 16px; letter-spacing: -0.02em; }
.hero p { font-size: 19px; color: var(--muted); max-width: 640px; margin: 0 auto 28px; }
.btn { display: inline-block; padding: 12px 20px; border-radius: 10px; font-weight: 600;
       text-decoration: none; border: 1px solid var(--line); color: var(--text); background: var(--card); }
.btn.primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.btn[aria-disabled="true"] { opacity: .55; pointer-events: none; }
.row { display: flex; gap: 12px; flex-wrap: wrap; justify-content: center; }
.note { color: var(--muted); font-size: 14px; margin-top: 12px; }
section { padding: 40px 0; }
h2 { font-size: 28px; margin: 0 0 20px; letter-spacing: -0.01em; }
.grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 20px; }
.card h3 { margin: 0 0 6px; font-size: 18px; }
.card p { margin: 0; color: var(--muted); }
.price { font-size: 34px; font-weight: 700; margin: 6px 0; }
.price small { font-size: 15px; color: var(--muted); font-weight: 500; }
.card .btn { margin-top: 14px; }
.dl .card { display: flex; flex-direction: column; justify-content: space-between; }
form { display: grid; gap: 12px; max-width: 460px; }
label { font-weight: 600; font-size: 14px; }
input { width: 100%; padding: 11px 12px; border-radius: 10px; border: 1px solid var(--line);
        background: var(--card); color: var(--text); font: inherit; }
.result { margin-top: 18px; word-break: break-all; }
.result code { display: block; padding: 12px; background: var(--card); border: 1px solid var(--line); border-radius: 10px; }
.error { color: #d1242f; }
footer { padding: 40px 0; color: var(--muted); font-size: 14px; border-top: 1px solid var(--line); margin-top: 40px; }