body {
    font-family: 'Noto Sans SC', sans-serif;
}
.drop-zone-active {
    border-color: #2563eb;
    background-color: #eff6ff;
}
.loader {
    border: 4px solid #f3f4f6;
    border-top: 4px solid #3b82f6;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
}
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}
.view { display: none; animation: fadeIn 0.5s; }
.view.active { display: block; }
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}