/* Engineering Knowledge Framework — Site Theme */

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --text: #1e293b;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --code-bg: #f1f5f9;
  --max-width: 960px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
}

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 1.5rem; }

/* Header */
.site-header {
  background: var(--bg-alt);
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo {
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--primary);
  text-decoration: none;
}
.site-nav a {
  margin-left: 1.5rem;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
}
.site-nav a:hover { color: var(--primary); }

/* Main */
main.container { padding-top: 2rem; padding-bottom: 4rem; }

/* Content */
.content h1 { font-size: 2rem; margin: 1.5rem 0 1rem; }
.content h2 { font-size: 1.5rem; margin: 1.5rem 0 0.75rem; padding-bottom: 0.3rem; border-bottom: 1px solid var(--border); }
.content h3 { font-size: 1.25rem; margin: 1.25rem 0 0.5rem; }
.content h4 { font-size: 1.1rem; margin: 1rem 0 0.5rem; }
.content p { margin-bottom: 1rem; }
.content ul, .content ol { margin: 0.5rem 0 1rem 1.5rem; }
.content li { margin-bottom: 0.25rem; }
.content a { color: var(--primary); text-decoration: none; }
.content a:hover { text-decoration: underline; }

.content blockquote {
  border-left: 3px solid var(--primary);
  margin: 1rem 0;
  padding: 0.5rem 1rem;
  background: var(--bg-alt);
  color: var(--text-muted);
}

.content code {
  background: var(--code-bg);
  padding: 0.15rem 0.4rem;
  border-radius: 3px;
  font-size: 0.9em;
  font-family: 'SF Mono', 'Fira Code', monospace;
}

.content pre {
  background: var(--code-bg);
  padding: 1rem;
  border-radius: 6px;
  overflow-x: auto;
  margin: 1rem 0;
  border: 1px solid var(--border);
}

.content pre code {
  background: none;
  padding: 0;
  font-size: 0.9rem;
}

.content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: 0.9rem;
}

.content th, .content td {
  border: 1px solid var(--border);
  padding: 0.5rem 0.75rem;
  text-align: left;
}

.content th {
  background: var(--bg-alt);
  font-weight: 600;
}

.content tr:nth-child(even) { background: var(--bg-alt); }

.content img { max-width: 100%; height: auto; }

/* Page title */
h1:first-child { margin-top: 0; }
.description { color: var(--text-muted); font-size: 1.1rem; margin-bottom: 2rem; }

/* Document list */
.document-list { list-style: none; padding: 0; }
.document-list li {
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border);
}
.document-list li:last-child { border-bottom: none; }
.document-list a { font-weight: 500; }

/* Capability grid */
.capability-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1rem;
  margin: 1rem 0 2rem;
}

.capability-card {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.25rem;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.capability-card:hover {
  border-color: var(--primary);
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.1);
}

.capability-card h3 {
  margin: 0;
  font-size: 1.1rem;
}

.capability-card h3 a {
  color: var(--text);
  text-decoration: none;
}

.capability-card h3 a:hover {
  color: var(--primary);
}

/* Footer */
.site-footer {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  color: var(--text-muted);
  font-size: 0.9rem;
  text-align: center;
}

/* Responsive */
@media (max-width: 768px) {
  body { font-size: 15px; }
  .site-header .container { flex-direction: column; gap: 0.5rem; }
  .site-nav a:first-child { margin-left: 0; }
}