body { font-family: Arial, sans-serif; margin: 0; padding: 0; background: #f9f9f9; }
header { background: #333; color: white; padding: 1rem; display: flex; justify-content: space-between; }
header a { color: white; text-decoration: none; margin-left: 1rem; }
main { padding: 2rem; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 1rem; }
.card { background: white; padding: 1rem; border-radius: 8px; box-shadow: 0 2px 4px rgba(0,0,0,0.1); }
.btn { display: inline-block; padding: 0.5rem 1rem; background: #28a745; color: white; border: none; border-radius: 4px; cursor: pointer; }