body { font-family: sans-serif; margin: 20px; }
nav a { margin-right: 10px; }
.alert { padding: 10px; margin-bottom: 10px; border: 1px solid transparent; border-radius: 4px; }
.alert-success { color: #155724; background-color: #d4edda; border-color: #c3e6cb; }
.alert-danger { color: #721c24; background-color: #f8d7da; border-color: #f5c6cb; }
.alert-warning { color: #856404; background-color: #fff3cd; border-color: #ffeeba; }
.alert-info { color: #0c5460; background-color: #d1ecf1; border-color: #bee5eb; }

#drop-zone {
    border: 2px dashed #ccc;
    border-radius: 10px;
    padding: 50px;
    text-align: center;
    cursor: pointer;
    margin-bottom: 20px;
}
#drop-zone.highlight {
    border-color: dodgerblue;
}
#upload-progress-container {
    margin-top: 10px;
}
#upload-progress {
    width: 100%;
}