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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: #000000;
    min-height: 100vh;
    padding: 20px;
    position: relative;
}

/* Back to Home Button - Liquid Glass Style */
.back-btn {
    position: fixed;
    top: 20px;
    left: 20px;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 12px 24px;
    background: rgba(40, 40, 40, 0.8);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border: 1px solid rgba(255, 255, 255, 0.18);
    border-radius: 12px;
    color: white;
    text-decoration: none;
    font-size: 16px;
    font-weight: 500;
    transition: all 0.3s ease;
    z-index: 9999;
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
    isolation: isolate;
    will-change: transform;
}

.back-btn:hover {
    background: rgba(60, 60, 60, 0.9);
    border: 1px solid rgba(255, 255, 255, 0.3);
    transform: translateX(-5px);
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.5);
}

.back-btn svg {
    width: 20px;
    height: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: rgba(20, 20, 20, 0.8);
    backdrop-filter: blur(10px);
    border-radius: 15px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.header {
    background: #000000;
    color: white;
    padding: 30px;
    text-align: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

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

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

.controls {
    padding: 20px;
    background: rgba(30, 30, 30, 0.5);
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: wrap;
}

/* Liquid Glass Button Style */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 12px;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
    background: rgba(108, 117, 125, 0.3);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(108, 117, 125, 0.4);
    color: white;
    font-weight: 500;
    box-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.15);
}

.btn-primary {
    background: rgba(108, 117, 125, 0.3);
    border: 1px solid rgba(108, 117, 125, 0.4);
}

.btn-primary:hover {
    background: rgba(108, 117, 125, 0.5);
    border: 1px solid rgba(108, 117, 125, 0.6);
    transform: translateY(-2px);
    box-shadow: 0 12px 40px 0 rgba(108, 117, 125, 0.3);
}

.btn-secondary {
    background: rgba(108, 117, 125, 0.3);
    border: 1px solid rgba(108, 117, 125, 0.4);
}

.btn-secondary:hover {
    background: rgba(108, 117, 125, 0.5);
    border: 1px solid rgba(108, 117, 125, 0.6);
    transform: translateY(-2px);
    box-shadow: 0 12px 40px 0 rgba(108, 117, 125, 0.3);
}

.pdf-viewer {
    width: 100%;
    height: 800px;
    border: none;
    background: white;
}

.fallback {
    padding: 40px;
    text-align: center;
    display: none;
    color: white;
}

.fallback h2 {
    color: #667eea;
    margin-bottom: 20px;
}

.fallback p {
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 20px;
}

/* Responsive Design */
@media (max-width: 768px) {
    body {
        padding: 10px;
    }
    
    .back-btn {
        top: 10px;
        left: 10px;
        padding: 10px 20px;
        font-size: 14px;
    }
    
    .header h1 {
        font-size: 1.8em;
    }
    
    .pdf-viewer {
        height: 600px;
    }
    
    .controls {
        padding: 15px;
    }
    
    .btn {
        font-size: 14px;
        padding: 10px 20px;
    }
}