/* Academic Portfolio Styles */

/* Custom CSS Variables for Academic Theme */
:root {
    --primary-blue: #1e3a8a;
    --secondary-blue: #3b82f6;
    --accent-blue: #60a5fa;
    --dark-blue: #1e40af;
    --light-blue: #dbeafe;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-600: #4b5563;
    --gray-800: #1f2937;
    --white: #ffffff;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.6;
    color: var(--gray-800);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    background-attachment: fixed;
    min-height: 100vh;
    position: relative;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 80%, rgba(120, 119, 198, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255, 255, 255, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(120, 119, 198, 0.2) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Crimson Text', 'Inter', serif;
    font-weight: 600;
    line-height: 1.3;
}

/* Navigation Styles */
nav {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
}

.nav-link {
    position: relative;
    color: var(--primary-blue);
    font-weight: 500;
    padding: 0.5rem 0;
    transition: all 0.3s ease;
    text-decoration: none;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--secondary-blue);
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

.nav-link:hover {
    color: var(--secondary-blue);
}

.mobile-nav-link {
    display: block;
    padding: 0.75rem 1rem;
    color: var(--primary-blue);
    font-weight: 500;
    text-decoration: none;
    transition: background-color 0.3s ease;
}

.mobile-nav-link:hover {
    background-color: var(--light-blue);
    color: var(--secondary-blue);
}

/* Social Icons */
.social-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 3rem;
    height: 3rem;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    color: white;
    font-size: 1.25rem;
    transition: all 0.3s ease;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
    text-decoration: none;
    border: 1px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
}

.social-icon:hover {
    background: var(--primary-blue);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* Research Cards */
.research-card {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 1rem;
    padding: 2rem;
    text-align: center;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
}

.research-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
    border-color: var(--accent-blue);
}

.research-icon {
    width: 4rem;
    height: 4rem;
    margin: 0 auto 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.9);
    border-radius: 1rem;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

/* Publication Cards */
.publication-card {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 1rem;
    padding: 1.5rem;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    border-left: 4px solid var(--secondary-blue);
    transition: all 0.3s ease;
    display: flex;
    gap: 1rem;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.publication-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateX(4px);
}

.publication-number {
    flex-shrink: 0;
    width: 2.5rem;
    height: 2.5rem;
    background: var(--secondary-blue);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.875rem;
}

.publication-content {
    flex: 1;
}

/* Project Cards */
.project-card {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 1rem;
    overflow: hidden;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
    border-color: var(--accent-blue);
}

.project-video {
    aspect-ratio: 16/9;
    background: linear-gradient(135deg, var(--gray-100) 0%, var(--gray-200) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
}

.video-placeholder {
    text-align: center;
    padding: 2rem;
}

.project-info {
    padding: 1.5rem;
}

/* Filter Buttons */
.filter-btn {
    padding: 0.5rem 1rem;
    background: white;
    border: 2px solid var(--gray-200);
    border-radius: 0.5rem;
    color: var(--gray-600);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--secondary-blue);
    border-color: var(--secondary-blue);
    color: white;
}

/* Contact Cards */
.contact-card {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 1rem;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.contact-card:hover {
    box-shadow: var(--shadow-md);
}

.contact-icon {
    flex-shrink: 0;
    width: 3rem;
    height: 3rem;
    background: var(--light-blue);
    border-radius: 0.75rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

/* Footer */
footer {
    background: rgba(30, 58, 138, 0.95);
    backdrop-filter: blur(20px);
    border-top: 1px solid rgba(255, 255, 255, 0.2);
}

/* Responsive Design */
@media (max-width: 768px) {
    .text-5xl {
        font-size: 2.5rem;
    }
    
    .text-7xl {
        font-size: 3rem;
    }
    
    .research-card,
    .project-card {
        margin-bottom: 1.5rem;
    }
    
    .publication-card {
        flex-direction: column;
        text-align: center;
    }
    
    .publication-number {
        margin: 0 auto 1rem;
    }
    
    .contact-card {
        flex-direction: column;
        text-align: center;
    }
    
    .contact-icon {
        margin: 0 auto 1rem;
    }
}

@media (max-width: 640px) {
    .grid {
        grid-template-columns: 1fr;
    }
    
    .flex-wrap {
        justify-content: center;
    }
}

/* Animation Classes */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.slide-in-left {
    opacity: 0;
    transform: translateX(-50px);
    transition: all 0.6s ease;
}

.slide-in-left.visible {
    opacity: 1;
    transform: translateX(0);
}

.slide-in-right {
    opacity: 0;
    transform: translateX(50px);
    transition: all 0.6s ease;
}

.slide-in-right.visible {
    opacity: 1;
    transform: translateX(0);
}

/* Loading Animation */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;