:root { --bg: #ffffff; --ink: #16181d; --muted: #5b6270; --line: #e3e6eb; --accent: #0f766e; --soft: #f3f6f8; }
@media (prefers-color-scheme: dark) {
  :root { --bg: #0f1216; --ink: #e8eaee; --muted: #9aa3b2; --line: #262c35; --accent: #2dd4bf; --soft: #161b22; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 17px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; }
main { max-width: 720px; margin: 0 auto; padding: 32px 16px 64px; }
header { display: flex; align-items: center; gap: 12px; padding-bottom: 16px; border-bottom: 1px solid var(--line); margin-bottom: 24px; }
header .brand { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font-family: Poppins, -apple-system, sans-serif; font-weight: 700; font-size: 22px; letter-spacing: -0.5px; }
header .brand b { color: #0d9488; font-weight: 700; }
header .brand .mark { width: 34px; height: 29px; color: var(--ink); }
nav { margin-left: auto; display: flex; gap: 16px; font-size: 15px; }
nav a { color: var(--muted); text-decoration: none; }
nav a:hover, nav a[aria-current] { color: var(--accent); }
h1 { font-size: 30px; line-height: 1.25; margin: 0 0 8px; }
h2 { font-size: 20px; margin: 32px 0 8px; }
p, li { color: var(--ink); }
.lede { color: var(--muted); font-size: 19px; }
.muted { color: var(--muted); font-size: 15px; }
a { color: var(--accent); }
.card { background: var(--soft); border: 1px solid var(--line); border-radius: 12px; padding: 16px 20px; margin: 16px 0; }
footer { margin-top: 48px; padding-top: 16px; border-top: 1px solid var(--line); color: var(--muted); font-size: 14px; }
header { flex-wrap: wrap; row-gap: 4px; }
@media (max-width: 480px) {
  nav { gap: 12px; font-size: 14px; }
  h1 { font-size: 26px; }
}
.app-icon { display: block; border-radius: 25px; box-shadow: 0 6px 20px rgba(0,0,0,.15); margin: 8px 0 20px; }