* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    color: #333;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 12px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 40px 30px;
    text-align: center;
}

header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
    font-weight: 700;
}

.subtitle {
    font-size: 1.1em;
    opacity: 0.9;
}

.pdf-container {
    padding: 30px;
}

.pdf-viewer {
    background: #f5f5f5;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    min-height: 600px;
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 20px;
    overflow: auto;
    position: relative;
}

#pdf-canvas {
    max-width: 100%;
    height: auto;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    margin: 20px;
}

.loading {
    text-align: center;
    color: #666;
    font-size: 1.2em;
}

.controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 15px;
    flex-wrap: wrap;
    padding: 20px;
    background: #f9f9f9;
    border-radius: 8px;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 6px;
    font-size: 1em;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 600;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
    transform: translateY(-2px);
}

.btn-download {
    background: #28a745;
    color: white;
}

.btn-download:hover {
    background: #218838;
    transform: translateY(-2px);
}

.page-info {
    font-size: 1.1em;
    font-weight: 600;
    color: #333;
    padding: 0 20px;
}

.info-box {
    background: #f8f9fa;
    padding: 25px;
    margin: 30px;
    border-radius: 8px;
    border-left: 4px solid #667eea;
}

.info-box h3 {
    margin-bottom: 15px;
    color: #333;
}

.info-box ol {
    margin-left: 20px;
    line-height: 1.8;
}

.info-box code {
    background: #e9ecef;
    padding: 2px 6px;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
}

@media (max-width: 768px) {
    header h1 {
        font-size: 1.8em;
    }
    
    .pdf-viewer {
        min-height: 400px;
    }
    
    .controls {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        max-width: 200px;
    }
}