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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #e0e0e0;
    background: #1a1a1a;
    animation: fadeInPage 0.5s ease-in;
    transition: opacity 0.3s ease-out; /* Add this for smooth transitions */
}

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

/* Back Button */
.back-button {
    position: fixed;
    top: 30px;
    left: 30px;
    padding: 12px 24px;
    background: #2a2a2a;
    color: #10b981;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 500;
    transition: all 0.3s ease;
    z-index: 1000;
    border: 1px solid #3a3a3a;
}

.back-button:hover {
    background: #10b981;
    color: #1a1a1a;
    transform: translateX(-5px);
    box-shadow: 0 5px 15px rgba(16, 185, 129, 0.3);
}

header {
    background: linear-gradient(135deg, #1a1a1a 0%, #2a2a2a 100%);
    color: white;
    padding: 60px 20px;
    text-align: center;
    border-bottom: 1px solid #3a3a3a;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    background: linear-gradient(90deg, #10b981, #34d399);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px;
}

section {
    background: #2a2a2a;
    border-radius: 10px;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.3);
    border: 1px solid #3a3a3a;
}

.project-overview {
    background: #2a2a2a;
}

section h2 {
    color: #10b981;
    margin-bottom: 20px;
    font-size: 1.8rem;
    border-bottom: 2px solid #10b981;
    padding-bottom: 10px;
}

section p {
    color: #b0b0b0;
    line-height: 1.8;
    margin-bottom: 15px;
}

/* PDF Container - Made Taller */
.pdf-section {
    background: #2a2a2a;
    padding: 30px;
    border-radius: 10px;
    margin-bottom: 30px;
    border: 1px solid #3a3a3a;
}

.pdf-container {
    width: 100%;
    height: 1100px; /* Increased from 600px */
    border: 2px solid #3a3a3a;
    border-radius: 8px;
    overflow: hidden;
    background: #1f1f1f;
}

.pdf-container embed {
    width: 100%;
    height: 100%;
}

.pdf-fallback {
    padding: 20px;
    text-align: center;
    background: #252525;
    border-radius: 8px;
    margin-top: 20px;
}

.pdf-fallback a {
    color: #10b981;
    text-decoration: none;
    font-weight: 500;
    padding: 10px 20px;
    border: 2px solid #10b981;
    border-radius: 6px;
    display: inline-block;
    transition: all 0.3s ease;
}

.pdf-fallback a:hover {
    background: #10b981;
    color: #1a1a1a;
    box-shadow: 0 5px 15px rgba(16, 185, 129, 0.3);
}

/* Key Features */
.key-features ul {
    list-style: none;
}

.key-features li {
    padding: 12px 0;
    padding-left: 30px;
    position: relative;
    color: #b0b0b0;
    border-bottom: 1px solid #3a3a3a;
}

.key-features li:last-child {
    border-bottom: none;
}

.key-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: #10b981;
    font-weight: bold;
    font-size: 1.2rem;
}

/* Technologies */
.tech-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 15px;
}

.tech-tag {
    background: #1f1f1f;
    color: #10b981;
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.9rem;
    border: 1px solid #10b981;
    transition: all 0.3s ease;
}

.tech-tag:hover {
    background: #10b981;
    color: #1a1a1a;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(16, 185, 129, 0.3);
}

footer {
    text-align: center;
    padding: 30px;
    color: #6b7280;
    border-top: 1px solid #3a3a3a;
    background: #1f1f1f;
}

/* Responsive */
@media (max-width: 1600px) {
    .back-button {
        display: none; /* Hide back button on mobile */
    }
}

@media (max-width: 768px) {    
    header h1 {
        font-size: 2rem;
    }
    
    section {
        padding: 20px;
    }
    
    .pdf-container {
        height: 500px; /* Smaller on mobile but still taller than before */
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 1.5rem;
    }
    
    section h2 {
        font-size: 1.4rem;
    }
    
    .tech-tag {
        font-size: 0.8rem;
        padding: 6px 12px;
    }
    
    .pdf-container {
        height: 400px;
    }
}

/* Fade out effect for navigation */
.fade-out {
    animation: fadeOut 0.3s ease-out forwards;
    pointer-events: none; /* Prevent interaction during fade */
}

@keyframes fadeOut {
    to {
        opacity: 0;
        transform: translateY(-20px);
    }
}