*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-bg: #ffffff;
  --color-text: #1a1a1a;
  --color-accent: #2563eb;
  --color-muted: #6b7280;
  --color-border: #e5e7eb;
  --max-width: 800px;
  --font: system-ui, -apple-system, sans-serif;
}

body {
  font-family: var(--font);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  font-size: 1.05rem;
}

/* Navigation */
header {
  border-bottom: 1px solid var(--color-border);
  padding: 1rem 2rem;
}

nav {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 2rem;
}

.site-title {
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--color-text);
  text-decoration: none;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

nav a {
  color: var(--color-muted);
  text-decoration: none;
  font-size: 0.95rem;
}

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

/* Main content */
main {
  max-width: var(--max-width);
  margin: 3rem auto;
  padding: 0 2rem;
}

h1 {
  font-size: 2rem;
  line-height: 1.2;
  margin-bottom: 1rem;
}

h2 { font-size: 1.5rem; margin: 2rem 0 0.75rem; }
h3 { font-size: 1.2rem; margin: 1.5rem 0 0.5rem; }

p { margin-bottom: 1rem; }

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

/* Hero section */
.hero h1 { font-size: 2.5rem; }
.hero .content { margin-top: 1.5rem; font-size: 1.1rem; }

/* Article */
article time {
  display: block;
  color: var(--color-muted);
  font-size: 0.875rem;
  margin-bottom: 2rem;
}

article .content { margin-top: 1rem; }

/* Post list */
.post-list {
  list-style: none;
  margin-top: 1.5rem;
}

.post-list li {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--color-border);
}

.post-list .date {
  color: var(--color-muted);
  font-size: 0.875rem;
}

/* Footer */
footer {
  border-top: 1px solid var(--color-border);
  text-align: center;
  padding: 2rem;
  color: var(--color-muted);
  font-size: 0.875rem;
  margin-top: 4rem;
}