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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Poppins', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

/* Research Sections */
.research-section {
    background: white;
    border-radius: 2rem;
    padding: 3rem;
    margin-bottom: 3rem;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.08);
    border: 1px solid rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
    animation: slide-in 0.6s ease-out;
}

.research-section:hover {
    transform: translateY(-5px);
    box-shadow: 0 25px 80px rgba(0, 0, 0, 0.12);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    background: linear-gradient(90deg, #2563eb, #7c3aed);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.research-content {
    font-size: 1.125rem;
    line-height: 1.8;
    color: #4b5563;
}

.research-content p {
    margin-bottom: 1.5rem;
}

/* Table of Contents Items */
.toc-item {
    display: flex;
    align-items: center;
    padding: 1rem 1.5rem;
    background: white;
    border-radius: 1rem;
    border: 2px solid transparent;
    transition: all 0.3s ease;
    text-decoration: none;
    color: #374151;
    font-weight: 500;
}

.toc-item:hover {
    border-color: #3b82f6;
    background: #f0f9ff;
    transform: translateX(10px);
}

.toc-item span {
    font-size: 1.25rem;
    margin-right: 0.75rem;
}

/* Architecture Diagram */
.architecture-diagram {
    background: linear-gradient(135deg, #f8fafc, #f1f5f9);
    border-radius: 1.5rem;
    padding: 2rem;
    margin: 2rem 0;
    border: 1px solid #e2e8f0;
}

.arch-layer {
    background: white;
    border-radius: 1rem;
    padding: 1.5rem;
    margin-bottom: 1rem;
    border-left: 4px solid #3b82f6;
    transition: all 0.3s ease;
}

.arch-layer:hover {
    transform: translateX(10px);
    box-shadow: 0 10px 30px rgba(59, 130, 246, 0.15);
}

.arch-layer h3 {
    color: #1e40af;
    font-weight: 700;
    margin-bottom: 0.5rem;
    font-size: 1.25rem;
}

.arch-layer p {
    color: #6b7280;
    font-size: 1rem;
}

/* Feature Cards */
.feature-card {
    background: #f8fafc;
    border-radius: 1rem;
    padding: 1.5rem;
    display: flex;
    align-items: center;
    transition: all 0.3s ease;
    border: 1px solid #e2e8f0;
}

.feature-card:hover {
    background: white;
    transform: translateY(-3px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.feature-card i {
    margin-right: 1rem;
    flex-shrink: 0;
}

.feature-card strong {
    color: #1f2937;
    margin-right: 0.5rem;
}

/* Tech Stack Grid */
.tech-stack-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.tech-category {
    background: #f9fafb;
    border-radius: 1.5rem;
    padding: 2rem;
    border: 1px solid #e5e7eb;
}

.tech-category h3 {
    color: #374151;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid #3b82f6;
}

.tech-item {
    background: white;
    border-radius: 1rem;
    padding: 1.5rem;
    margin-bottom: 1rem;
    border: 1px solid #e5e7eb;
    transition: all 0.3s ease;
}

.tech-item:hover {
    border-color: #3b82f6;
    transform: translateY(-2px);
}

.tech-item h4 {
    color: #1f2937;
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.tech-stats {
    display: flex;
    gap: 1rem;
    margin-bottom: 0.75rem;
    flex-wrap: wrap;
}

.tech-stats .stat {
    background: #e0f2fe;
    color: #0369a1;
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.875rem;
    font-weight: 500;
}

.tech-item p {
    color: #6b7280;
    font-size: 0.95rem;
    line-height: 1.5;
}

/* Code Snippet */
.code-snippet {
    background: #1e293b;
    border-radius: 1rem;
    padding: 2rem;
    margin: 2rem 0;
    overflow-x: auto;
    position: relative;
}

.code-snippet::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, #8b5cf6, #3b82f6);
    border-radius: 9999px;
}

.code-snippet h4 {
    color: #e2e8f0;
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
}

.code-snippet h4::before {
    content: '</>';
    margin-right: 0.75rem;
    color: #8b5cf6;
    font-weight: 700;
}

.code-snippet pre {
    margin: 0;
}

.code-snippet code {
    color: #cbd5e1;
    font-family: 'Menlo', 'Monaco', 'Courier New', monospace;
    font-size: 0.95rem;
    line-height: 1.5;
}

.code-snippet .keyword {
    color: #f472b6;
}

.code-snippet .string {
    color: #34d399;
}

.code-snippet .comment {
    color: #94a3b8;
}

/* Buttons */
.btn-primary,
.btn-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2rem;
    border-radius: 9999px;
    font-weight: 600;
    font-size: 1.125rem;
    text-decoration: none;
    transition: all 0.3s ease;
    gap: 0.75rem;
}

.btn-primary {
    background: white;
    color: #3b82f6;
    box-shadow: 0 10px 30px rgba(59, 130, 246, 0.25);
}

.btn-primary:hover {
    background: #f0f9ff;
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 20px 40px rgba(59, 130, 246, 0.35);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.15);
    color: white;
    backdrop-filter: blur(10px);
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.25);
    transform: translateY(-3px);
    border-color: white;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes glowPulse {
    0%, 100% {
        box-shadow: 0 0 20px rgba(59, 130, 246, 0.3);
    }
    50% {
        box-shadow: 0 0 40px rgba(59, 130, 246, 0.6);
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    .section-title {
        font-size: 2rem;
    }
    
    .research-section {
        padding: 2rem;
        border-radius: 1.5rem;
    }
    
    .tech-stack-grid {
        grid-template-columns: 1fr;
    }
    
    .toc-item {
        padding: 0.875rem 1rem;
    }
}

@media (max-width: 480px) {
    .section-title {
        font-size: 1.75rem;
        flex-direction: column;
        align-items: flex-start;
    }
    
    .section-title i {
        margin-bottom: 0.5rem;
        margin-right: 0;
    }
    
    .feature-card {
        flex-direction: column;
        text-align: center;
        align-items: center;
    }
    
    .feature-card i {
        margin-right: 0;
        margin-bottom: 0.75rem;
    }
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: #f1f5f9;
    border-radius: 9999px;
}

::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, #3b82f6, #8b5cf6);
    border-radius: 9999px;
}

::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(180deg, #2563eb, #7c3aed);
}

/* Selection Color */
::selection {
    background: rgba(59, 130, 246, 0.3);
    color: inherit;
}

/* Print Styles */
@media print {
    .research-section {
        break-inside: avoid;
        box-shadow: none;
        border: 1px solid #ddd;
    }
    
    .btn-primary,
    .btn-secondary,
    .toc-item {
        display: none;
    }
}