/* Modern CSS for PDF Flipbook Converter */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

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

header {
    text-align: center;
    margin-bottom: 40px;
    color: white;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

.upload-section {
    background: white;
    border-radius: 15px;
    padding: 40px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    margin-bottom: 30px;
}

.upload-area {
    border: 3px dashed #ddd;
    border-radius: 10px;
    padding: 60px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #fafafa;
}

.upload-area:hover,
.upload-area.dragover {
    border-color: #667eea;
    background: #f0f4ff;
    transform: translateY(-2px);
}

.upload-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

.upload-icon {
    width: 60px;
    height: 60px;
    color: #667eea;
}

.file-icon {
    width: 60px;
    height: 60px;
    color: #28a745;
}

.upload-content h3 {
    font-size: 1.5rem;
    color: #333;
    margin: 0;
}

.upload-content p {
    color: #666;
    margin: 0;
}

.browse-link {
    color: #667eea;
    text-decoration: underline;
    cursor: pointer;
}

.change-file {
    color: #667eea;
    font-size: 0.9rem;
    cursor: pointer;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 15px 40px;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: block;
    margin: 20px auto 0;
    min-width: 200px;
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-primary:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

.btn-secondary {
    background: white;
    color: #667eea;
    border: 2px solid #667eea;
    padding: 10px 25px;
    border-radius: 25px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin: 5px;
}

.btn-secondary:hover {
    background: #667eea;
    color: white;
    transform: translateY(-1px);
}

.result-section {
    background: white;
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    margin-bottom: 30px;
}

.result-content h3 {
    color: #28a745;
    margin-bottom: 20px;
    font-size: 1.5rem;
}

.result-actions {
    text-align: center;
    margin-bottom: 25px;
}

.embed-info {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
    border-left: 4px solid #667eea;
}

.embed-info h4 {
    color: #333;
    margin-bottom: 10px;
}

.embed-info p {
    color: #666;
    margin-bottom: 10px;
}

.embed-url {
    background: white;
    padding: 10px;
    border-radius: 5px;
    border: 1px solid #ddd;
    font-family: monospace;
    word-break: break-all;
    color: #667eea;
    font-weight: 500;
}

.btn-loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid #ffffff;
    border-radius: 50%;
    border-top-color: transparent;
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.result-section {
    animation: slideIn 0.5s ease-out;
}

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