body {
    font-family: 'Inter', sans-serif;
    transition: background-color 0.3s, color 0.3s;
}
.dark body {
    background: linear-gradient(to bottom right, #1f2937, #111827);
    color: #e5e7eb;
}
h1 {
    font-family: 'Poppins', sans-serif;
    background: linear-gradient(to right, #2563eb, #7c3aed);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}
#sidebar {
    width: 250px;
    background: #ffffff;
    transition: transform 0.3s ease;
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.1);
}
.dark #sidebar {
    background: #1f2937;
}
#sidebar.hidden {
    transform: translateX(-250px);
}
#sidebar button {
    transition: all 0.2s;
}
#sidebar button:hover {
    background: #2563eb;
    color: white;
    transform: translateX(10px);
}
#dropZone, #pdfDropZone, #excelDropZone, #pdfWordDropZone, #wordDropZone, #pdfPptDropZone, #pptDropZone, #pdfJpgDropZone, #jpgDropZone {
    border: 3px dashed #93c5fd;
    padding: 40px;
    background: linear-gradient(to bottom, #f0f9ff, #ffffff);
    border-radius: 12px;
    transition: all 0.3s ease;
}
.dark #dropZone, .dark #pdfDropZone, .dark #excelDropZone, .dark #pdfWordDropZone, .dark #wordDropZone, .dark #pdfPptDropZone, .dark #pptDropZone, .dark #pdfJpgDropZone, .dark #jpgDropZone {
    background: linear-gradient(to bottom, #374151, #1f2937);
    border-color: #4b5563;
}
#dropZone.dragover, #pdfDropZone.dragover, #excelDropZone.dragover, #pdfWordDropZone.dragover, #wordDropZone.dragover, #pdfPptDropZone.dragover, #pptDropZone.dragover, #pdfJpgDropZone.dragover, #jpgDropZone.dragover {
    border-color: #2563eb;
    background: #dbeafe;
    transform: scale(1.03);
    box-shadow: 0 0 20px rgba(37, 99, 235, 0.5);
}
.dark #dropZone.dragover, .dark #pdfDropZone.dragover, .dark #excelDropZone.dragover, .dark #pdfWordDropZone.dragover, .dark #wordDropZone.dragover, .dark #pdfPptDropZone.dragover, .dark #pptDropZone.dragover, .dark #pdfJpgDropZone.dragover, .dark #jpgDropZone.dragover {
    background: #4b5563;
}
.image-preview {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
    gap: 20px;
    margin-top: 25px;
}
.image-preview img {
    width: 100%;
    height: 130px;
    object-fit: cover;
    border-radius: 10px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    transition: transform 0.3s, box-shadow 0.3s;
}
.image-preview img:hover {
    transform: scale(1.08);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.25);
}
.loader {
    border: 6px solid #e5e7eb;
    border-top: 6px solid #2563eb;
    border-radius: 50%;
    width: 60px;
    height: 60px;
    animation: spin 1s linear infinite, pulse 1.5s infinite;
    display: none;
    margin: 30px auto;
}
.dark .loader {
    border-color: #4b5563;
    border-top-color: #60a5fa;
}
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}
@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.1); }
    100% { transform: scale(1); }
}
.remove-btn {
    transition: all 0.2s;
}
.remove-btn:hover {
    background-color: #dc2626;
    transform: scale(1.2);
}
.progress-bar {
    height: 6px;
    background: #e5e7eb;
    border-radius: 3px;
    overflow: hidden;
    display: none;
    margin-top: 20px;
}
.progress-bar-fill {
    height: 100%;
    background: #2563eb;
    width: 0;
    transition: width 0.3s;
}
.dark .progress-bar {
    background: #4b5563;
}
.dark .progress-bar-fill {
    background: #60a5fa;
}
.toast {
    position: fixed;
    bottom: 20px;
    right: 20px;
    padding: 12px 24px;
    border-radius: 8px;
    color: white;
    opacity: 0;
    transition: opacity 0.3s;
    z-index: 1000;
}
.toast.success {
    background: #10b981;
}
.toast.error {
    background: #ef4444;
}
@media (max-width: 768px) {
    #sidebar {
        position: fixed;
        top: 0;
        left: 0;
        height: 100%;
        z-index: 1000;
    }
    #main-content {
        margin-left: 0;
    }
}