body { font-family: Arial, sans-serif; margin: 0; padding: 0; }
header { background: #003366; padding: 10px; color: white; text-align: center; }
nav ul { list-style-type: none; padding: 0; text-align: center; }
nav ul li { display: inline; margin-right: 20px; }
nav ul li a { color: white; text-decoration: none; font-weight: bold; }
.hero { background: url('assets/banner_openpdk.png') no-repeat center center; background-size: cover; text-align: center; padding: 100px 0; color: white; position: relative; }
.hero-overlay { background: rgba(0, 0, 0, 0.5); padding: 50px; display: inline-block; border-radius: 10px; }
footer { background: #003366; color: white; text-align: center; padding: 10px; width: 100%; position: relative; }