:root {
  --blue: #2563EB;
  --cyan: #06B6D4;
  --ink: #0F172A;
  --text: #334155;
  --muted: #64748B;
  --line: #E2E8F0;
  --soft: #F8FAFC;
  --grad: linear-gradient(135deg, var(--blue), var(--cyan));
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: Poppins, "Segoe UI", Arial, sans-serif; color: var(--text); background: #fff; line-height: 1.75; }
a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { max-width: 860px; margin: 0 auto; padding: 0 20px; }

header { position: sticky; top: 0; z-index: 10; background: rgba(255,255,255,.92); backdrop-filter: blur(8px); border-bottom: 1px solid var(--line); }
.nav { max-width: 1100px; display: flex; align-items: center; justify-content: space-between; height: 68px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 24px; letter-spacing: -.5px; color: var(--ink); }
.brand:hover { text-decoration: none; }
.brand svg { width: 38px; height: 38px; }
.brand .x { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.back { font-weight: 500; font-size: 14px; color: var(--muted); }

.hero { background: var(--soft); border-bottom: 1px solid var(--line); padding: 44px 0 36px; }
.crumb { font-size: 14px; color: var(--muted); }
.crumb a { color: var(--muted); }
.hero h1 { font-size: clamp(30px, 5vw, 44px); color: var(--ink); line-height: 1.2; margin: 10px 0 6px; }
.updated { font-size: 14px; color: var(--muted); }

article { padding: 40px 0 24px; }
article h2 { font-size: 22px; color: var(--ink); margin: 36px 0 10px; padding-top: 4px; }
article h3 { font-size: 17px; color: var(--ink); margin: 22px 0 6px; }
article p { margin: 0 0 12px; }
article ul { margin: 0 0 14px 22px; }
article li { margin: 4px 0; }
article strong { color: var(--ink); }

.toc { background: var(--soft); border: 1px solid var(--line); border-radius: 14px; padding: 18px 22px; margin: 6px 0 8px; }
.toc b { display: block; color: var(--ink); margin-bottom: 6px; }
.toc ol { margin-left: 20px; columns: 2; column-gap: 32px; font-size: 15px; }

.address { background: var(--soft); border: 1px solid var(--line); border-radius: 14px; padding: 18px 22px; margin-top: 10px; }

.cta { margin: 36px 0 56px; text-align: center; background: var(--ink); color: #CBD5E1; border-radius: 20px; padding: 36px 24px; }
.cta h3 { color: #fff; font-size: 22px; margin-bottom: 6px; }
.cta a.btn { display: inline-block; margin-top: 16px; padding: 12px 24px; border-radius: 12px; background: var(--grad); color: #fff; font-weight: 600; }
.cta a.btn:hover { text-decoration: none; transform: translateY(-1px); }

footer { border-top: 1px solid var(--line); padding: 24px 0; color: var(--muted); font-size: 14px; }
footer .wrap { max-width: 1100px; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; }
footer a { color: var(--muted); margin-left: 16px; }

@media (max-width: 640px) { .toc ol { columns: 1; } .back { display: none; } }