:root {
  --primary: #2D4EF5;
  --primary-weak: #EAF0FF;
  --ink: #141A2E;
  --ink-soft: #4A5268;
  --ink-faint: #8790A6;
  --bg: #FFFFFF;
  --bg-soft: #F5F7FC;
  --border: #E6EAF3;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: 'Manrope', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { width: 100%; max-width: 820px; margin: 0 auto; padding: 0 24px; }

/* Header */
header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid rgba(230, 234, 243, 0.7);
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  height: 72px; max-width: 1160px; margin: 0 auto; padding: 0 24px;
}
.brand { display: flex; align-items: center; gap: 12px; font-weight: 800; font-size: 19px; letter-spacing: -0.02em; color: var(--ink); }
.brand:hover { text-decoration: none; }
.brand img { width: 34px; height: 34px; border-radius: 9px; }
.back { font-weight: 600; font-size: 15px; color: var(--ink-soft); }
.back:hover { color: var(--ink); text-decoration: none; }

/* Document body */
.doc { padding: 56px 0 80px; }
.doc-head { margin-bottom: 40px; padding-bottom: 28px; border-bottom: 1px solid var(--border); }
.doc-head .eyebrow { color: var(--primary); font-weight: 700; font-size: 14px; letter-spacing: 0.06em; text-transform: uppercase; margin-bottom: 12px; }
.doc-head h1 { font-size: clamp(30px, 5vw, 44px); letter-spacing: -0.03em; line-height: 1.1; font-weight: 800; }
.doc-head .updated { color: var(--ink-faint); font-size: 14px; margin-top: 14px; font-weight: 500; }

.doc h2 { font-size: 22px; font-weight: 800; letter-spacing: -0.02em; margin: 40px 0 12px; scroll-margin-top: 88px; }
.doc h3 { font-size: 17px; font-weight: 700; margin: 24px 0 8px; }
.doc p { color: var(--ink-soft); font-size: 16px; margin-bottom: 16px; }
.doc ul { color: var(--ink-soft); font-size: 16px; margin: 0 0 16px 22px; }
.doc li { margin-bottom: 8px; }
.doc strong { color: var(--ink); font-weight: 700; }
.doc .small-caps { font-size: 15px; }

.callout {
  background: var(--primary-weak); border: 1px solid #d7e2ff; border-radius: 12px;
  padding: 18px 20px; margin: 24px 0;
}
.callout p { margin: 0; font-size: 15px; color: var(--ink); }

.toc {
  background: var(--bg-soft); border: 1px solid var(--border); border-radius: 14px;
  padding: 22px 24px; margin-bottom: 44px;
}
.toc h2 { font-size: 13px; text-transform: uppercase; letter-spacing: 0.06em; color: var(--ink-faint); margin: 0 0 12px; font-weight: 700; }
.toc ol { margin-left: 18px; color: var(--ink-soft); font-size: 15px; columns: 2; column-gap: 32px; }
.toc li { margin-bottom: 6px; break-inside: avoid; }
@media (max-width: 560px) { .toc ol { columns: 1; } }

/* Support page */
.contact {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 18px;
  background: var(--primary-weak); border: 1px solid #d7e2ff; border-radius: 16px;
  padding: 26px 28px; margin: 8px 0 44px;
}
.contact .c-text h2 { margin: 0 0 4px; font-size: 20px; font-weight: 800; letter-spacing: -0.02em; }
.contact .c-text p { margin: 0; font-size: 15px; color: var(--ink-soft); }
.contact .c-btn {
  background: var(--primary); color: #fff; font-weight: 700; font-size: 15px;
  padding: 13px 24px; border-radius: 999px; white-space: nowrap;
  box-shadow: 0 10px 24px -8px rgba(45, 78, 245, 0.55);
}
.contact .c-btn:hover { text-decoration: none; opacity: 0.92; }

.faq-item { padding: 22px 0; border-bottom: 1px solid var(--border); }
.faq-item:last-child { border-bottom: none; }
.faq-item h3 { margin: 0 0 8px; font-size: 18px; font-weight: 700; }
.faq-item p { margin: 0; }

/* Footer */
footer { padding: 40px 0; border-top: 1px solid var(--border); }
.foot { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 16px; max-width: 1160px; margin: 0 auto; padding: 0 24px; }
.foot-links { display: flex; gap: 24px; flex-wrap: wrap; }
.foot-links a { color: var(--ink-soft); font-size: 14px; font-weight: 500; }
.foot-copy { color: var(--ink-faint); font-size: 13px; }
@media (max-width: 560px) { .foot { flex-direction: column; text-align: center; } }