/* Design tokens, reset and base typography. */
:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --surface-2: #eef0f3;
  --text: #1c2024;
  --muted: #5b6472;
  --border: #e3e6ea;
  --brand: #357ce1;
  --brand-text: #ffffff;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
  --radius: 12px;
}

/* Dark theme: follows the OS, and an explicit toggle (data-theme) wins. */
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1216;
    --surface: #181c22;
    --surface-2: #20262e;
    --text: #e6e9ee;
    --muted: #9aa4b2;
    --border: #2a3038;
    --shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
  }
}
:root[data-theme='dark'] {
  --bg: #0f1216;
  --surface: #181c22;
  --surface-2: #20262e;
  --text: #e6e9ee;
  --muted: #9aa4b2;
  --border: #2a3038;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
}
:root[data-theme='light'] {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --surface-2: #eef0f3;
  --text: #1c2024;
  --muted: #5b6472;
  --border: #e3e6ea;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
}

* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.65 system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
}
a {
  color: var(--brand);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}
h1,
h2,
h3,
h4 {
  line-height: 1.25;
  letter-spacing: -0.01em;
}
img {
  max-width: 100%;
}
.wrap {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 1.2rem;
}
.muted {
  color: var(--muted);
}