.header{text-align:center;margin-bottom:40px}.header h1{color:rgba(0,0,0,0);font-size:2.5rem;font-weight:700;margin-bottom:10px;font-family:poppins}.header p{color:#7f8c8d;font-size:1.1rem}.upload-area.dragover{border-color:#2980b9;background:#e8f4f8;transform:scale(1.02)}@media (max-width:768px){.header h1{font-size:2rem}}