:root {
  --bg: #0b1020;
  --surface: #111934;
  --text: #f4f7ff;
  --muted: #b8c0d9;
  --accent: #2bd576;
  --border: rgba(255, 255, 255, 0.15);
}
* { box-sizing: border-box; }
body {
  background: radial-gradient(circle at top, #12214a 0%, var(--bg) 55%);
  color: var(--text);
  line-height: 1.5;
}
.wrap {
  max-width: 1120px;
  margin: 0 auto;
  padding: 24px 16px 48px;
}
.home-link {
  color: var(--muted);
  text-decoration: none;
  display: inline-block;
  margin-bottom: 12px;
}
.home-link:hover { color: #fff; }
h1 {
  margin: 0 0 10px;
  font-size: clamp(1.9rem, 5vw, 2.6rem);
  line-height: 1.2;
}
.intro {
  margin: 0 0 18px;
  color: var(--muted);
  max-width: 920px;
}
.hero-image {
  width: 100%;
  height: auto;
  max-height: 360px;
  display: block;
  border-radius: 14px;
  border: 1px solid var(--border);
  margin-bottom: 20px;
  object-fit: cover;
}
.tool-shell {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
}
.tool-frame {
  width: 100%;
  min-height: 72vh;
  border: 0;
  display: block;
  background: #080c18;
}
.fallback {
  padding: 14px 16px 18px;
  border-top: 1px solid var(--border);
  color: var(--muted);
}
.fallback a, #info a, .topic-nav a {
  color: var(--accent);
  font-weight: 700;
  text-decoration: none;
}
.fallback a:hover, #info a:hover, .topic-nav a:hover { text-decoration: underline; }
.topic-nav ul {
  list-style: none;
  margin: 22px 0;
  padding: 0;
  display: grid;
  gap: 10px;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}
.topic-nav li {
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 12px;
}
#info {
  margin-top: 28px;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 20px;
}
#info h2 { margin-top: 22px; }
#info h2:first-child { margin-top: 0; }
#info table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 10px;
}
#info th, #info td {
  border: 1px solid var(--border);
  padding: 8px;
  text-align: left;
}
#info details {
  margin-bottom: 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px;
  background: rgba(255,255,255,0.02);
}
footer {
  margin-top: 24px;
  color: var(--muted);
  font-size: 0.95rem;
}
@media (max-width: 768px) {
  .hero-image { max-height: 240px; }
  .tool-frame { min-height: 66vh; }
}