:root {
  --bg: #f5f7fb;
  --card: #fff;
  --text: #1f2937;
  --muted: #475569;
  --line: #e5e7eb;
  --purple: #667eea;
  --blue: #764ba2;
  --radius: 18px;
  --shadow: 0 18px 45px rgba(31, 41, 55, .1);
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; line-height: 1.75; }
a { color: #5144a0; text-underline-offset: .2em; }
a:hover { text-decoration-thickness: 2px; }
a:focus-visible, summary:focus-visible { outline: 3px solid #5144a0; outline-offset: 4px; }
.page { width: min(1120px, calc(100% - 32px)); margin: auto; padding: 28px 0 48px; }
.site-header { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 16px; margin-bottom: 22px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--text); font-size: 1.2rem; font-weight: 800; text-decoration: none; }
.brand-mark { display: grid; place-items: center; width: 38px; height: 38px; border-radius: 12px; background: linear-gradient(135deg, var(--purple), var(--blue)); color: #fff; }
.header-note, .source-note, .site-footer { color: var(--muted); font-size: .92rem; }
.hero, .content-section, .cta-box { padding: 28px; border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); margin-top: 24px; background: var(--card); }
.hero { background: linear-gradient(135deg, rgba(102,126,234,.08), rgba(118,75,162,.08)); }
h1 { margin: 0 0 16px; font-size: clamp(1.8rem, 4vw, 2.8rem); line-height: 1.2; }
h2 { margin: 0 0 12px; line-height: 1.35; font-size: 1.45rem; }
h3 { line-height: 1.4; }
p { margin: 0 0 16px; }
li { margin-bottom: 8px; }
.btn { display: inline-block; padding: 12px 20px; border-radius: 999px; background: #5144a0; color: #fff; text-decoration: none; font-weight: 700; }
.btn:hover { background: #403580; }
.guide-links, .footer-links { display: flex; flex-wrap: wrap; gap: 12px 20px; }
.table-wrap { overflow-x: auto; }
table { border-collapse: collapse; width: 100%; margin: 16px 0; }
th, td { padding: 12px; border: 1px solid var(--line); text-align: left; vertical-align: top; }
th { background: var(--bg); }
caption { font-weight: 700; text-align: left; }
details { border-top: 1px solid var(--line); padding: 14px 0; }
summary { cursor: pointer; font-weight: 700; }
details p { margin-top: 12px; }
.site-footer { margin-top: 28px; }
@media (max-width: 640px) {
  .page { width: calc(100% - 24px); padding-top: 18px; }
  .hero, .content-section, .cta-box { padding: 20px; }
}