.drop-zone {
    border: 3px dashed #ced4da;
    border-radius: 15px;
    cursor: pointer;
    transition: all 0.3s ease;
    background-color: #f8f9fa;
}

.drop-zone:hover, .drop-zone.active {
    border-color: #007bff;
    background-color: #e9ecef;
}

.drop-zone i {
    color: #007bff;
}

.preview-item {
    width: 150px;
    margin: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    border-radius: 8px;
    overflow: hidden;
    background: #fff;
    transition: transform 0.2s;
}

.preview-item:hover {
    transform: translateY(-5px);
}

.preview-item img {
    width: 100%;
    height: auto;
    display: block;
}

.preview-item .page-num {
    padding: 5px;
    text-align: center;
    background: #f8f9fa;
    font-size: 12px;
    border-top: 1px solid #eee;
}

#preview-grid {
    max-height: 400px;
    overflow-y: auto;
    padding: 20px;
    background: #f0f2f5;
    border-radius: 10px;
}

.btn-lg {
    font-weight: 600;
    padding: 12px 30px;
    border-radius: 50px;
}

.card {
    border-radius: 20px;
}