:root {
  --primary: #1e90ff;
  --accent: #ff9800;
  --bg: #121212;
  --card: #1e1e1e;
  --border: #333;
  --text: #f5f5f5;
  font-family: 'Segoe UI', Roboto, sans-serif;
}

body {
  background: var(--bg);
  color: var(--text);
}

html, body {
  margin: 0;
  background: var(--bg);
}

header {
  padding: 1rem;
  text-align: center;
  background: var(--bg);
  color: #fff;
}

h1, h2 {
  margin: .5em 0;
}

.card {
  max-width: 720px;
  margin: 2rem auto;
  padding: 1.5rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
}

.hidden {
  display: none;
}

.btn {
  margin: .5rem;
  padding: .6rem 1.2rem;
  border: 0;
  border-radius: 5px;
  background: var(--primary);
  color: #fff;
  cursor: pointer;
}

.btn.primary {
  background: var(--accent);
}

.btn:disabled {
  opacity: .6;
  cursor: not-allowed;
}

.focus-card {
  background-color: #2a2a2a !important;
  color: var(--text) !important;
  border: 1px solid var(--border);
  padding: 1rem;
  border-radius: 8px;
  margin: 1rem 0;
}

.dimension-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}

.dimension-card {
  background: #2a2a2a;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
  color: var(--text);
  text-align: center;
}

.dimension-card h3 {
  color: var(--primary);
  margin-bottom: 0.5rem;
}