:root {
  --bg-light: #ffffff;
  --bg-dark: #0d1117;
  --text-light: #0d1117;
  --text-dark: #e6edf3;
  --primary: #007BFF;
}

body {
  font-family: 'Segoe UI', Tahoma, sans-serif;
  margin: 0;
  padding: 0;
  background-color: var(--bg-light);
  color: var(--text-light);
  transition: all 0.3s ease;
}

@media (prefers-color-scheme: dark) {
  body { background-color: var(--bg-dark); color: var(--text-dark); }
  header, footer { background-color: #161b22; }
  a { color: #58a6ff; }
}

header, footer {
  text-align: center;
  padding: 20px;
  background-color: var(--primary);
  color: white;
}

nav a {
  color: white;
  margin: 0 10px;
  text-decoration: none;
}

.container {
  max-width: 900px;
  margin: auto;
  padding: 20px;
}

.call-btn {
  display: inline-block;
  background-color: var(--primary);
  color: white;
  padding: 12px 24px;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 600;
}

.plan-card {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 15px;
  margin-top: 20px;
}

.card {
  border: 1px solid #ccc;
  padding: 20px;
  border-radius: 10px;
  background-color: rgba(0,0,0,0.03);
  text-align: center;
}

footer p { font-size: 0.9em; }
img, svg { width: 100%; max-width: 400px; display: block; margin: auto; }