:root { --bg: #f5f8f8; --card: #ffffff; --text: #16232a; --muted: #5b6b73; --accent: #1f9e94; --line: rgba(22,35,42,.08); --shadow: 0 8px 30px rgba(22,35,42,.06); }
@media (prefers-color-scheme: dark) {
  :root { --bg: #0f1719; --card: #172124; --text: #eef4f4; --muted: #97a8ad; --accent: #4fd1c5; --line: rgba(255,255,255,.08); --shadow: none; }
}
html, body { margin: 0; background: var(--bg); color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", "Pretendard", "Segoe UI", sans-serif; line-height: 1.6; }
a { color: var(--accent); }
.wrap { max-width: 760px; margin: 0 auto; padding: 48px 20px 64px; }
header { display: flex; align-items: center; gap: 14px; margin-bottom: 28px; }
header img { width: 56px; height: 56px; border-radius: 14px; }
header h1 { font-size: 26px; margin: 0; letter-spacing: -0.01em; }
header p { margin: 2px 0 0; color: var(--muted); font-size: 14px; }
section { background: var(--card); border: 1px solid var(--line); border-radius: 16px; padding: 24px 26px; margin-bottom: 20px; box-shadow: var(--shadow); }
h2 { font-size: 20px; margin: 0 0 12px; }
h3 { font-size: 15px; margin: 18px 0 6px; color: var(--muted); font-weight: 600; }
p, li { font-size: 15.5px; margin: 6px 0; }
ul { padding-left: 20px; }
kbd { font: 600 12px -apple-system, "SF Mono", Menlo, monospace; padding: 1px 6px; border-radius: 5px; background: var(--line); }
.updated { color: var(--muted); font-size: 13px; }
footer { color: var(--muted); font-size: 13px; text-align: center; margin-top: 24px; }
footer a { color: var(--muted); }

/* language index: sticks to the top so any section is one tap away */
nav.langs { position: sticky; top: 0; z-index: 2; display: flex; gap: 8px; flex-wrap: wrap; padding: 10px 0 12px; margin: -8px 0 16px;
  background: var(--bg); border-bottom: 1px solid var(--line); }
nav.langs a { text-decoration: none; font-size: 14px; font-weight: 600; color: var(--text); padding: 6px 12px; border-radius: 999px;
  border: 1px solid var(--line); background: var(--card); }
nav.langs a:hover { border-color: var(--accent); color: var(--accent); }
html { scroll-behavior: smooth; }
section[id] { scroll-margin-top: 64px; }