body {font-family: Arial, sans-serif; margin: 0; padding: 0; background: #f4f4f4; color: #333;}
header {background: #2c3e50; color: #fff; padding: 20px; text-align: center;}
main {max-width: 900px; margin: 20px auto; padding: 0 15px;}
section {background: #fff; padding: 20px; margin-bottom: 20px; border-radius: 8px; box-shadow: 0 2px 6px rgba(0,0,0,0.1);}
.dropzone {border: 2px dashed #bbb; padding: 20px; text-align: center; border-radius: 8px; background: #fafafa; cursor: pointer;}
.dropzone.dragover {border-color: #2c3e50; background: #eef2f5;}
.preview {margin-top: 15px; height: 400px; border: 1px solid #ccc; border-radius: 8px; overflow: hidden;}
.preview iframe {width: 100%; height: 100%; border: none;}
button {background: #27ae60; color: #fff; border: none; padding: 10px 15px; cursor: pointer; border-radius: 5px;}
button:hover {background: #219150;}
input[type="file"] {margin-top: 10px;}
footer {text-align: center; padding: 15px; font-size: 14px; background: #f1f1f1; color: #555;}