:root {
  --accent: #2357e6;
  --text: #16181d;
  --muted: #5b6270;
  --border: #e3e6ec;
  --bg: #ffffff;
  --surface: #f5f7fa;
}

@media (prefers-color-scheme: dark) {
  :root {
    --accent: #6f95ff;
    --text: #eceef2;
    --muted: #a1a8b5;
    --border: #2c313a;
    --bg: #111317;
    --surface: #1a1d23;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-text-size-adjust: 100%;
}

header, main, footer {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 20px;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 24px;
  padding-bottom: 24px;
}

.brand {
  font-weight: 700;
  font-size: 22px;
  color: var(--accent);
  text-decoration: none;
  letter-spacing: -0.01em;
}

nav a {
  color: var(--muted);
  text-decoration: none;
  margin-left: 18px;
  font-size: 15px;
}
nav a:hover { color: var(--text); }

main { padding-bottom: 48px; }

h1 { font-size: 34px; line-height: 1.2; letter-spacing: -0.02em; margin: 16px 0 8px; }
h2 { font-size: 22px; margin: 36px 0 8px; }
h3 { font-size: 18px; margin: 24px 0 4px; }

a { color: var(--accent); }

.lede { font-size: 20px; color: var(--muted); margin-top: 0; }
.meta { color: var(--muted); font-size: 15px; }

ul { padding-left: 22px; }
li { margin: 4px 0; }

.box {
  background: var(--surface);
  border-radius: 14px;
  padding: 18px 20px;
  margin: 20px 0;
}
.box p:first-child { margin-top: 0; }
.box p:last-child, .box ul:last-child { margin-bottom: 0; }

footer {
  border-top: 1px solid var(--border);
  padding-top: 20px;
  padding-bottom: 40px;
  color: var(--muted);
  font-size: 14px;
}
footer a { color: var(--muted); }