:root {
  color-scheme: light;
  --page-bg: #f7f7f5;
  --surface-bg: #ffffff;
  --text-primary: #171717;
  --text-secondary: #5c5c5c;
  --border-color: #d8d8d8;
  --link-color: #2457a6;
  --button-bg: #ffffff;
  --button-hover-bg: #eeeeeb;
  --focus-color: #1d4ed8;
  font-family: system-ui, sans-serif;
  line-height: 1.7;
}
html[data-theme="dark"] {
  color-scheme: dark;
  --page-bg: #121212;
  --surface-bg: #1b1b1b;
  --text-primary: #eeeeee;
  --text-secondary: #b8b8b8;
  --border-color: #3a3a3a;
  --link-color: #9dc1ff;
  --button-bg: #242424;
  --button-hover-bg: #303030;
  --focus-color: #a9c7ff;
}
* { box-sizing: border-box; }
body { margin: 0 auto; max-width: 48rem; padding: 1rem; color: var(--text-primary); background: var(--page-bg); }
a { color: var(--link-color); }
h1, h2, h3, h4, h5, h6 { color: var(--text-primary); }
time { color: var(--text-secondary); }
img { display: block; max-width: 100%; height: auto; filter: none; }
.site-header { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: .5rem 0 2rem; font-weight: 700; }
.theme-toggle {
  min-width: 5rem;
  border: 1px solid var(--border-color);
  border-radius: .5rem;
  padding: .55rem .8rem;
  color: var(--text-primary);
  background: var(--button-bg);
  font: inherit;
  cursor: pointer;
}
.theme-toggle:hover { background: var(--button-hover-bg); }
.theme-toggle:focus-visible { outline: 3px solid var(--focus-color); outline-offset: 3px; }
main { min-height: 70vh; }
.hero { padding: 3rem 0; }
.eyebrow { color: var(--text-secondary); font-size: .8rem; letter-spacing: .12em; text-transform: uppercase; }
.article-list { list-style: none; padding: 0; }
.article-list li { display: flex; flex-wrap: wrap; gap: .75rem; justify-content: space-between; border: 1px solid var(--border-color); border-radius: .75rem; padding: .8rem; background: var(--surface-bg); }
.article-body { margin-top: 2rem; font-size: 1.0625rem; line-height: 1.8; }
.article-body > h1:first-child { display: none; }
.article-body p { margin: 0 0 1.35em; }
article > h1 { font-size: clamp(2rem, 4vw, 2.5rem); line-height: 1.3; }
footer { border-top: 1px solid var(--border-color); color: var(--text-secondary); padding: 1rem 0; }
@media (max-width: 42rem) {
  body { padding: 1.25rem; }
  .hero { padding: 2rem 0; }
  article > h1 { font-size: clamp(1.875rem, 8vw, 2rem); line-height: 1.35; }
  .article-body { font-size: 1.125rem; line-height: 1.88; }
  .article-body p { margin-bottom: 1.4em; }
}