/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Header Styles */
header {
    text-align: center;
    margin-bottom: 40px;
    color: white;
}

header h1 {
    font-size: 3rem;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

header h1 i {
    margin-right: 15px;
    color: #ffd700;
}

header p {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* Main Content */
main {
    background: white;
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    margin-bottom: 30px;
}

/* Upload Section */
.upload-section {
    margin-bottom: 30px;
}

.upload-area {
    border: 3px dashed #667eea;
    border-radius: 15px;
    padding: 60px 20px;
    text-align: center;
    background: #f8f9ff;
    transition: all 0.3s ease;
    cursor: pointer;
}

.upload-area:hover {
    border-color: #764ba2;
    background: #f0f2ff;
    transform: translateY(-2px);
}

.upload-area.dragover {
    border-color: #28a745;
    background: #f0fff4;
    transform: scale(1.02);
}

.upload-content i {
    font-size: 4rem;
    color: #667eea;
    margin-bottom: 20px;
    display: block;
}

.upload-content h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: #333;
}

.upload-content p {
    color: #666;
    font-size: 1rem;
}

/* Options Section */
.options-section {
    margin-bottom: 30px;
    padding: 25px;
    background: #f8f9fa;
    border-radius: 15px;
    border-left: 5px solid #667eea;
}

.options-section h3 {
    margin-bottom: 20px;
    color: #333;
    display: flex;
    align-items: center;
    gap: 10px;
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.option-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.option-group label {
    font-weight: 600;
    color: #555;
    display: flex;
    align-items: center;
    gap: 8px;
}

.option-group input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: #667eea;
}

.option-group select,
.option-group input[type="number"],
.option-group input[type="range"] {
    padding: 12px;
    border: 2px solid #e1e5e9;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.option-group select:focus,
.option-group input:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.option-group input[type="range"] {
    padding: 0;
    height: 8px;
    background: #e1e5e9;
    border-radius: 4px;
    -webkit-appearance: none;
}

.option-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    background: #667eea;
    border-radius: 50%;
    cursor: pointer;
}

#qualityValue {
    font-weight: 600;
    color: #667eea;
    margin-left: 10px;
}

/* Files Section */
.files-section {
    margin-bottom: 30px;
}

.files-section h3 {
    margin-bottom: 20px;
    color: #333;
    display: flex;
    align-items: center;
    gap: 10px;
}

.files-list {
    display: grid;
    gap: 15px;
}

.file-item {
    display: flex;
    align-items: center;
    padding: 15px;
    background: #f8f9fa;
    border-radius: 10px;
    border: 1px solid #e1e5e9;
    transition: all 0.3s ease;
}

.file-item:hover {
    background: #e9ecef;
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.file-preview {
    width: 60px;
    height: 60px;
    border-radius: 8px;
    object-fit: cover;
    margin-right: 15px;
    border: 2px solid #e1e5e9;
}

.file-info {
    flex: 1;
}

.file-name {
    font-weight: 600;
    color: #333;
    margin-bottom: 5px;
}

.file-details {
    font-size: 0.9rem;
    color: #666;
}

.file-actions {
    display: flex;
    gap: 10px;
}

.file-status {
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
}

.file-status.pending {
    background: #fff3cd;
    color: #856404;
}

.file-status.converting {
    background: #d1ecf1;
    color: #0c5460;
}

.file-status.completed {
    background: #d4edda;
    color: #155724;
}

.file-status.error {
    background: #f8d7da;
    color: #721c24;
}

/* Action Buttons */
.actions-section {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 30px;
}

.btn {
    padding: 15px 30px;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    min-width: 150px;
    justify-content: center;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(0,0,0,0.2);
}

.btn:active {
    transform: translateY(0);
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-secondary {
    background: linear-gradient(135deg, #28a745 0%, #20c997 100%);
    color: white;
}

.btn-outline {
    background: transparent;
    color: #667eea;
    border: 2px solid #667eea;
}

.btn-outline:hover {
    background: #667eea;
    color: white;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.btn:disabled:hover {
    transform: none;
    box-shadow: none;
}

/* Progress Section */
.progress-section {
    margin-bottom: 30px;
    text-align: center;
}

.progress-bar {
    width: 100%;
    height: 20px;
    background: #e1e5e9;
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 15px;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
    width: 0%;
    transition: width 0.3s ease;
    border-radius: 10px;
}

#progressText {
    color: #666;
    font-weight: 600;
}

/* Footer */
footer {
    text-align: center;
    color: white;
    opacity: 0.8;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    main {
        padding: 20px;
    }
    
    .options-grid {
        grid-template-columns: 1fr;
    }
    
    .actions-section {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 300px;
    }
    
    .file-item {
        flex-direction: column;
        text-align: center;
    }
    
    .file-preview {
        margin-right: 0;
        margin-bottom: 10px;
    }
    
    .file-actions {
        margin-top: 10px;
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 1.5rem;
    }
    
    .upload-content i {
        font-size: 3rem;
    }
    
    .upload-content h3 {
        font-size: 1.2rem;
    }
}

/* Animation Classes */
.fade-in {
    animation: fadeIn 0.5s ease-in;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.slide-in {
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Loading Spinner */
.spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid #f3f3f3;
    border-top: 3px solid #667eea;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}