:root {
  --bg-page:   #f7f7f4;
  --bg-card:   #ffffff;
  --text:      #2c2c2c;
  --muted:     #6b6b6b;
  --light:     #f0f0ec;
  --border:    #e2e2dc;
  --link:      #4a627a;
  --link-hov:  #2c3e50;
  --accent:    #8b9d83;
  --radius:    5px;
}

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

body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg-page);
  color: var(--text);
  line-height: 1.75;
  font-size: 15px;
}

header {
  max-width: 760px;
  margin: 2.5rem auto 0;
  padding: 0 1rem;
}

header h1 {
  font-size: 1.4rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

header .tagline {
  font-size: 13px;
  color: var(--muted);
  margin-top: 0.15rem;
}

nav {
  max-width: 760px;
  margin: 1.25rem auto 0;
  padding: 0 1rem;
  display: flex;
  gap: 1.25rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.6rem;
}

nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.01em;
  padding-bottom: 0.55rem;
  margin-bottom: -0.6rem;
  border-bottom: 2px solid transparent;
  transition: color 0.15s;
}

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

nav a.active {
  color: var(--text);
  border-bottom-color: var(--accent);
}

main {
  max-width: 760px;
  margin: 1.75rem auto;
  padding: 0 1rem;
}

h2 { font-size: 1.05rem; margin: 1.5rem 0 0.5rem; font-weight: 600; }
p  { margin-bottom: 0.7rem; }
.sub { color: var(--muted); margin-bottom: 1.5rem; font-size: 13px; }

ul { padding-left: 1.25rem; margin-bottom: 0.75rem; }
li { margin-bottom: 0.2rem; }

a { color: var(--link); text-decoration: none; }
a:hover { color: var(--link-hov); text-decoration: underline; }

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  margin-bottom: 0.75rem;
}

.card h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.2rem;
}

.card-date {
  font-size: 11px;
  color: var(--muted);
  margin-bottom: 0.5rem;
}

code {
  background: var(--light);
  padding: 0.1rem 0.4rem;
  border-radius: 3px;
  font-size: 13px;
  font-family: "SF Mono", "Fira Code", "Cascadia Code", monospace;
  color: #404040;
}

pre {
  background: var(--light);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  margin: 0.5rem 0 0.75rem;
  overflow-x: auto;
  font-size: 12.5px;
  font-family: "SF Mono", "Fira Code", "Cascadia Code", monospace;
  line-height: 1.6;
  color: #404040;
}

footer {
  max-width: 760px;
  margin: 2rem auto;
  padding: 0 1rem;
  border-top: 1px solid var(--border);
  padding-top: 0.6rem;
  font-size: 11px;
  color: var(--muted);
}

@media (max-width: 600px) {
  body { font-size: 14px; }
  header { margin-top: 1.5rem; }
  nav { gap: 0.75rem; flex-wrap: wrap; }
  nav a { font-size: 12px; }
  main { margin: 1rem auto; }
  h1 { font-size: 1.2rem; }
}