* { box-sizing: border-box; }
body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  margin: 0;
  color: #1a1a1a;
  background: #fafaf7;
  line-height: 1.55;
}
.banner {
  background: #c0392b;
  color: #fff;
  padding: 0.75rem 1rem;
  font-size: 0.95rem;
  text-align: center;
  border-bottom: 4px solid #7f231a;
}
.banner a { color: #ffe; text-decoration: underline; }
.topnav {
  background: #2c3e50;
  padding: 0.5rem 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
}
.topnav a {
  color: #ecf0f1;
  text-decoration: none;
  padding: 0.4rem 0.8rem;
  border-radius: 4px;
  font-size: 0.95rem;
}
.topnav a:hover { background: #34495e; }
.topnav a.active { background: #16a085; }
main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
}
h1 { color: #2c3e50; border-bottom: 2px solid #16a085; padding-bottom: 0.3rem; }
h2 { color: #34495e; margin-top: 2rem; }
h3 { color: #34495e; }
a { color: #16a085; }
code {
  background: #f0ede6;
  padding: 0.1em 0.35em;
  border-radius: 3px;
  font-size: 0.92em;
}
pre {
  background: #2c3e50;
  color: #ecf0f1;
  padding: 1rem;
  overflow-x: auto;
  border-radius: 4px;
}
pre code { background: none; color: inherit; padding: 0; }
pre.mermaid {
  background: #fff;
  color: #333;
  text-align: center;
  padding: 1rem 0.5rem;
  border: 1px solid #ddd;
}
blockquote {
  border-left: 4px solid #16a085;
  background: #ecf7f4;
  margin: 1rem 0;
  padding: 0.5rem 1rem;
}
table {
  border-collapse: collapse;
  width: 100%;
  margin: 1rem 0;
  font-size: 0.92rem;
}
th, td { border: 1px solid #ddd; padding: 0.5rem 0.6rem; text-align: left; vertical-align: top; }
th { background: #ecf0f1; }
tr:nth-child(even) td { background: #fafaf7; }
.bom-wrap { overflow-x: auto; }
.bom { font-size: 0.88rem; }
.bom td:nth-child(7) { font-size: 0.82rem; color: #555; max-width: 380px; }
.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1rem;
  margin: 1rem 0;
}
.gallery figure {
  margin: 0;
  background: #fff;
  border: 1px solid #ddd;
  border-radius: 4px;
  overflow: hidden;
}
.gallery img { width: 100%; height: auto; display: block; }
.gallery figcaption { padding: 0.5rem 0.75rem; font-size: 0.88rem; }
.viewer-wrap { margin: 1rem 0; }
.viewer-wrap .caption { font-size: 0.88rem; color: #555; margin-top: 0.3rem; }
.dxf-list { line-height: 1.9; }
.lede { font-size: 1.05rem; color: #444; }
footer {
  border-top: 1px solid #ddd;
  background: #ecf0f1;
  padding: 1rem;
  text-align: center;
  font-size: 0.85rem;
  color: #555;
}
footer a { color: #16a085; }
.build-info {
  margin-top: 0.4rem;
  font-size: 0.78rem;
  color: #777;
}
.build-info code { background: #dcdcdc; }
@media (max-width: 600px) {
  .banner { font-size: 0.85rem; }
  main { padding: 1rem 0.75rem 2rem; }
}