body { font-family: 'Segoe UI', sans-serif; margin: 0; padding: 0; background: #f4f6f9; color: #333; }
header { background: #23282d; color: #fff; padding: 20px; text-align: center; }
.container { max-width: 900px; margin: 30px auto; background: #fff; padding: 30px; border-radius: 5px; box-shadow: 0 2px 5px rgba(0,0,0,0.05); }