:root {
  --bg: #0f172a;
  --card: #1e293b;
  --text: #e5e7eb;
  --accent: #38bdf8;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: 'Inter', sans-serif;
  background: var(--bg);
  color: var(--text);
}

a { color: var(--accent); text-decoration: none; }

header {
  padding: 1.2rem 2rem;
  background: #020617;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid #1e293b;
}

nav a {
  margin-left: 1.5rem;
  font-weight: 500;
}

main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 2rem;
}

.category {
  background: rgba(30, 41, 59, 0.6);
  border: 1px solid #1e293b;
  border-radius: 18px;
  padding: 1.5rem;
  margin: 1.5rem 0;
  box-shadow: 0 12px 30px rgba(2, 6, 23, 0.35);
}

.category-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.category-header h2 {
  margin: 0;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
}

.card {
  background: var(--card);
  padding: 1.5rem;
  border-radius: 14px;
  transition: transform 0.2s, box-shadow 0.2s;
  cursor: pointer;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 30px rgba(0,0,0,0.4);
}

.hidden { display: none; }

h1, h2 { margin-top: 0; }

footer {
  text-align: center;
  padding: 2rem;
  opacity: 0.6;
}

model-viewer {
  width: 100%;
  height: 420px;
  background: #020617;
  border-radius: 14px;
  margin-top: 1rem;
}