:root {
  --ink: #1a2420; --ink-soft: #4b5b54; --paper: #faf9f6; --paper-raised: #ffffff;
  --line: #dde3de; --accent: #2f6f4f; --accent-soft: #e6efe9; --accent-ink: #ffffff;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --ink: #eef2ef; --ink-soft: #a9b6b0; --paper: #121712; --paper-raised: #182019;
    --line: #2a352e; --accent: #6fbf94; --accent-soft: #1c2b22; --accent-ink: #0f1a13;
  }
}
:root[data-theme="dark"] {
  --ink: #eef2ef; --ink-soft: #a9b6b0; --paper: #121712; --paper-raised: #182019;
  --line: #2a352e; --accent: #6fbf94; --accent-soft: #1c2b22; --accent-ink: #0f1a13;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; line-height: 1.55; padding: 0 16px 56px; }
.wrap { max-width: 720px; margin: 0 auto; }
header.top { display: flex; align-items: center; justify-content: space-between; padding: 18px 0; gap: 12px; }
.mark { display: inline-flex; align-items: center; gap: 10px; font-size: 13px; letter-spacing: .08em; text-transform: uppercase; color: var(--accent); font-weight: 700; text-decoration: none; }
.mark::before { content: ""; width: 10px; height: 10px; border-radius: 3px; background: var(--accent); display: inline-block; }
nav a { color: var(--ink-soft); text-decoration: none; font-size: 14px; margin-left: 16px; }
nav a:hover { color: var(--accent); }
h1 { font-family: Georgia, "Times New Roman", serif; font-size: clamp(30px, 6vw, 44px); line-height: 1.12; margin: 28px 0 14px; text-wrap: balance; }
h2 { font-family: Georgia, "Times New Roman", serif; font-size: clamp(21px, 4vw, 26px); margin: 40px 0 10px; }
h3 { font-size: 15px; margin: 18px 0 6px; }
p { margin: 0 0 12px; }
.sub { font-size: 17px; color: var(--ink-soft); max-width: 56ch; margin-bottom: 24px; }
.btn { display: inline-block; background: var(--accent); color: var(--accent-ink); padding: 12px 18px; border-radius: 8px; font-weight: 600; text-decoration: none; }
.btn.ghost { background: var(--accent-soft); color: var(--accent); }
.btn + .btn { margin-left: 10px; }
.card { background: var(--paper-raised); border: 1px solid var(--line); border-radius: 10px; padding: 18px 20px; margin: 14px 0; }
.card h3 { margin-top: 0; }
.grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
@media (max-width: 520px) { .grid { grid-template-columns: 1fr; } .btn + .btn { margin-left: 0; margin-top: 10px; } }
.steps { counter-reset: s; padding: 0; margin: 0; list-style: none; }
.steps li { counter-increment: s; display: flex; gap: 14px; padding: 10px 0; border-bottom: 1px solid var(--line); }
.steps li::before { content: counter(s); flex: none; width: 28px; height: 28px; border-radius: 50%; background: var(--accent-soft); color: var(--accent); font-weight: 700; display: inline-flex; align-items: center; justify-content: center; }
.sample { background: var(--accent-soft); border-radius: 12px; padding: 14px 16px; font-size: 15px; max-width: 46ch; }
table { width: 100%; border-collapse: collapse; font-size: 15px; }
td, th { padding: 9px 4px; border-bottom: 1px solid var(--line); text-align: left; }
td:last-child, th:last-child { text-align: right; }
.muted { color: var(--ink-soft); font-size: 14px; }
.notice { border-left: 4px solid var(--accent); padding: 10px 14px; background: var(--paper-raised); border-radius: 0 8px 8px 0; margin: 14px 0; font-size: 15px; }
footer { margin-top: 48px; padding-top: 18px; border-top: 1px solid var(--line); font-size: 13px; color: var(--ink-soft); }
footer a { color: var(--accent); }
details summary { cursor: pointer; font-weight: 600; padding: 8px 0; }
ul { padding-left: 20px; }