:root {
  --paper: #ffffff;
  --ink: #0d0d0d;
  --ink-2: #5f5f64;
  --ink-3: #9a9aa0;
  --surface: #f5f5f6;
  --line: rgba(0, 0, 0, 0.08);
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #000000;
    --ink: #f5f5f5;
    --ink-2: #a0a0a6;
    --ink-3: #6a6a70;
    --surface: #141415;
    --line: rgba(255, 255, 255, 0.12);
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 17px/1.6 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Inter", "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.wrap { max-width: 720px; margin: 0 auto; padding: 0 20px; }

header.bar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 22px 0; border-bottom: 1px solid var(--line);
}

.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font-weight: 600; }

.mark {
  width: 28px; height: 28px; border-radius: 8px; background: var(--ink);
  display: inline-flex; flex-direction: column; justify-content: center; align-items: flex-start;
  gap: 3px; padding-left: 6px;
}
.mark i { display: block; height: 3px; border-radius: 2px; background: var(--paper); }
.mark i:first-child { width: 13px; }
.mark i:last-child { width: 8px; margin-left: 5px; }

nav a { color: var(--ink-2); text-decoration: none; margin-left: 18px; font-size: 15px; }
nav a:hover { color: var(--ink); }

main { padding: 48px 0 72px; }

h1 { font-size: 40px; line-height: 1.1; letter-spacing: -0.02em; margin: 0 0 12px; }
h2 { font-size: 22px; letter-spacing: -0.01em; margin: 40px 0 8px; }
h3 { font-size: 17px; margin: 24px 0 4px; }
p, li { color: var(--ink-2); }
strong { color: var(--ink); }
a { color: var(--ink); }
.lede { font-size: 20px; color: var(--ink-2); margin: 0 0 32px; }
.meta { color: var(--ink-3); font-size: 14px; margin-bottom: 32px; }

.card { background: var(--surface); border-radius: 18px; padding: 20px 22px; margin: 16px 0; }
.card p { margin: 6px 0 0; }

.button {
  display: inline-block; background: var(--ink); color: var(--paper); text-decoration: none;
  padding: 14px 24px; border-radius: 999px; font-weight: 600;
}

.grid { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); margin: 32px 0; }
.grid .card { margin: 0; }
.grid h3 { margin: 0; }

footer { border-top: 1px solid var(--line); padding: 24px 0 40px; color: var(--ink-3); font-size: 14px; }
footer a { color: var(--ink-3); margin-right: 16px; }

@media (max-width: 480px) {
  h1 { font-size: 32px; }
  nav a { margin-left: 12px; }
}