@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
    /* Professional Color Palette */
    --primary-navy: #1a365d;
    --primary-blue: #2563eb;
    --primary-light: #3b82f6;
    --accent-teal: #0891b2;
    --accent-green: #059669;
    --accent-purple: #7c3aed;
    
    /* Neutral Colors */
    --white: #ffffff;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    
    /* Semantic Colors */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--primary-blue) 0%, var(--accent-teal) 100%);
    --gradient-secondary: linear-gradient(135deg, var(--accent-purple) 0%, var(--primary-light) 100%);
    --gradient-accent: linear-gradient(135deg, var(--accent-green) 0%, var(--accent-teal) 100%);
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Spacing */
    --section-padding: 100px 0;
    --container-padding: 0 24px;
    --max-width: 1200px;
}

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

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--gray-800);
    background-color: var(--white);
    overflow-x: hidden;
}

/* Multi-page Layout */
.page {
    min-height: 100vh;
    display: none;
    opacity: 0;
    transform: translateX(50px);
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    padding-top: 70px; /* Account for fixed nav */
}

.page.active {
    display: block;
    opacity: 1;
    transform: translateX(0);
}

.page.fade-in {
    animation: pageSlideIn 0.6s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

.page.fade-out {
    animation: pageSlideOut 0.4s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

@keyframes pageSlideIn {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes pageSlideOut {
    from {
        opacity: 1;
        transform: translateX(0);
    }
    to {
        opacity: 0;
        transform: translateX(-30px);
    }
}

/* Page Content Styling */
.page-content {
    padding: 40px 0;
    min-height: calc(100vh - 140px); /* Account for nav and footer */
}

/* Utility Classes */
.section-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: var(--container-padding);
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 1rem;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--gray-600);
    max-width: 600px;
    margin: 0 auto;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 12px 24px;
    font-size: 1rem;
    font-weight: 500;
    border-radius: 8px;
    text-decoration: none;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--white);
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: var(--gradient-secondary);
    color: var(--white);
    box-shadow: var(--shadow-md);
}

.btn-secondary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-outline {
    background: transparent;
    color: var(--primary-blue);
    border: 2px solid var(--primary-blue);
}

.btn-outline:hover {
    background: var(--primary-blue);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-sm {
    padding: 8px 16px;
    font-size: 0.875rem;
}

/* Scroll Progress - Hidden in multi-page mode */
.scroll-progress {
    display: none;
}

/* Navigation */
.main-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--gray-200);
    z-index: 999;
    transition: all 0.3s ease;
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    cursor: pointer;
}

.logo-text {
    font-size: 1.5rem;
    color: var(--primary-navy);
}

.logo-subtitle {
    font-size: 0.875rem;
    color: var(--gray-500);
    font-weight: 400;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 2rem;
    list-style: none;
    margin: 0;
}

.nav-link {
    text-decoration: none;
    color: var(--gray-700);
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
    cursor: pointer;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-blue);
}

.nav-link::before {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-blue);
    transition: width 0.3s ease;
}

.nav-link:hover::before,
.nav-link.active::before {
    width: 100%;
}

.resume-link {
    background: var(--gradient-primary);
    color: var(--white) !important;
    padding: 8px 16px;
    border-radius: 6px;
    box-shadow: var(--shadow-sm);
}

.resume-link:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.resume-link::before {
    display: none;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--gray-700);
    transition: all 0.3s ease;
}

/* Hero Section */
.hero-section {
    padding: 50px 0;
    background: linear-gradient(135deg, var(--gray-50) 0%, var(--white) 100%);
    position: relative;
    overflow: hidden;
}

.hero-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: var(--container-padding);
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: 4rem;
    align-items: center;
}

.hero-badge {
    display: inline-block;
    background: var(--gradient-accent);
    color: var(--white);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
}

.hero-title {
    margin-bottom: 1.5rem;
}

.title-main {
    display: block;
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--gray-900);
    line-height: 1.1;
    margin-bottom: 0.5rem;
}

.title-gradient {
    display: block;
    font-size: 2rem;
    font-weight: 600;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-description {
    font-size: 1.25rem;
    color: var(--gray-600);
    margin-bottom: 2rem;
    max-width: 600px;
}

.hero-stats {
    display: flex;
    gap: 2rem;
    margin-bottom: 2.5rem;
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-blue);
    line-height: 1;
}

.stat-label {
    display: block;
    font-size: 0.875rem;
    color: var(--gray-500);
    margin-top: 0.25rem;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.hero-image {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.image-container {
    position: relative;
    width: 430px;
    height: 430px;
}

.photo-frame {
    width: 350px;
    height: 350px;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    position: relative;
    z-index: 2;
    margin: 40px auto;
}

.photo-placeholder {
    width: 100%;
    height: 100%;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 4rem;
}

.floating-elements {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
}

.float-icon {
    position: absolute;
    font-size: 2rem;
    opacity: 0.1;
    animation: gentleFloat 6s ease-in-out infinite;
    animation-delay: var(--delay, 0s);
}

.ai-icon { top: 20%; right: 10%; }
.security-icon { bottom: 30%; left: 5%; }
.quantum-icon { top: 10%; left: 15%; }
.network-icon { bottom: 10%; right: 20%; }

@keyframes gentleFloat {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(5deg); }
}

/* About Section */
.about-section {
    padding: var(--section-padding);
    background: var(--white);
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about-intro {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    align-items: start;
}

.intro-text p {
    font-size: 1.125rem;
    color: var(--gray-600);
    margin-bottom: 1.5rem;
}

.achievements h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 1rem;
}

.achievements ul {
    list-style: none;
}

.achievements li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--gray-600);
}

.achievements li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success);
    font-weight: bold;
}

/* Research Section */
.research-section {
    padding: var(--section-padding);
    background: var(--gray-50);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.research-card {
    background: var(--white);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    border-top: 4px solid transparent;
}

.research-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.research-card:nth-child(1) { border-top-color: var(--primary-blue); }
.research-card:nth-child(2) { border-top-color: var(--accent-teal); }
.research-card:nth-child(3) { border-top-color: var(--accent-purple); }
.research-card:nth-child(4) { border-top-color: var(--accent-green); }

.card-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.card-icon {
    width: 50px;
    height: 50px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--white);
}

.research-card:nth-child(1) .card-icon { background: var(--primary-blue); }
.research-card:nth-child(2) .card-icon { background: var(--accent-teal); }
.research-card:nth-child(3) .card-icon { background: var(--accent-purple); }
.research-card:nth-child(4) .card-icon { background: var(--accent-green); }

.card-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-900);
}

.card-content p {
    color: var(--gray-600);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.card-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.tag {
    background: var(--gray-100);
    color: var(--gray-700);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
}

/* Publications Section */
/* Publications Section */
.publications-section {
    padding: var(--section-padding); /* Uses your global padding variable */
    background: var(--white); /* White background for this section */
}

.publications-list {
    max-width: 900px; /* Max width for the content area */
    margin: 0 auto; /* Center the list */
    border: 1px solid var(--gray-200); /* Subtle border for a structured look */
    border-radius: 8px; /* Rounded corners for the entire list container */
    overflow: hidden; /* Ensures child elements respect the border-radius */
    box-shadow: var(--shadow-sm); /* Light shadow for depth */
}

.publication-header {
    display: grid;
    /* Defines 2 columns: Year (60px fixed width) and Title (remaining space) */
    grid-template-columns: 60px 1fr;
    background-color: var(--gray-100); /* Light gray background for the header */
    padding: 1rem 1.5rem; /* Padding inside the header */
    font-weight: 600; /* Bolder text for headers */
    color: var(--gray-700); /* Darker gray text */
    border-bottom: 1px solid var(--gray-200); /* Separator line below header */
    gap: 1rem; /* Space between grid columns */
    border-radius: 8px 8px 0 0; /* Rounded top corners to match the list container */
    align-items: center; /* Vertically align items in the header */
}

.publication-header .header-item {
    padding: 0.5rem 0; /* Vertical padding for header text */
}

.pub-year-header {
    text-align: center; /* Center the "Year" text in the header */
}

.publication-item {
    display: grid;
    /* Defines 2 columns: Year (60px fixed width) and Content (remaining space) */
    grid-template-columns: 60px 1fr;
    gap: 1rem; /* Space between grid columns */
    padding: 1rem 1.5rem; /* Padding inside each publication item */
    border-bottom: 1px solid var(--gray-100); /* Lighter separator between items */
    align-items: start; /* Align content to the top within the grid row */
    transition: background-color 0.2s ease; /* Smooth hover effect */
}

.publication-item:last-child {
    border-bottom: none; /* No border for the last item */
}

.publication-item:hover {
    background-color: var(--gray-50); /* Subtle background change on hover */
}

.pub-year {
    font-size: 0.95rem; /* Slightly smaller font size for the year */
    font-weight: 600; /* Bolder text */
    color: var(--gray-700); /* Darker gray text */
    text-align: center; /* Center the year text */
    padding: 0.5rem 0; /* Vertical padding */
    align-self: center; /* Vertically center the year in its grid cell */
}

.pub-content {
    display: flex;
    flex-direction: column; /* Stack title, authors, venue vertically */
    gap: 0.25rem; /* Small spacing between stacked elements */
}

.pub-title {
    font-size: 1.05rem; /* Slightly smaller font size for compactness */
    font-weight: 600; /* Bolder title */
    color: var(--primary-blue); /* Distinct blue color for titles */
    margin-bottom: 0; /* Remove default paragraph margin */
    line-height: 1.3; /* Compact line height */
    text-decoration: none; /* Remove default underline from links if it were a link */
}

/* Optional: If you want titles to be clickable (even without a separate link element, using JS) */
.pub-title:hover {
    text-decoration: underline; /* Underline on hover for titles (suggests clickability) */
    cursor: pointer; /* Indicate it's interactive */
}


.pub-authors {
    font-size: 0.9rem; /* Smaller font size for author list */
    color: var(--gray-600); /* Softer gray color */
    margin-bottom: 0; /* Remove default margin */
}

.pub-venue {
    font-size: 0.9rem; /* Smaller font size for venue */
    font-weight: 500; /* Medium font weight */
    color: var(--gray-500); /* Even softer gray color */
    margin-bottom: 0; /* Remove default margin */
}

/* The .pub-actions div is now empty in HTML, so we can hide it or let it collapse */
.pub-actions {
    display: none; /* Ensure it takes no space */
}

/* Call to Action below publications */
.pub-cta {
    text-align: center;
    margin-top: 3rem; /* Space from the publications list */
}

/* Responsive adjustments for publications section */
@media (max-width: 768px) {
    .publication-header {
        /* Adjust columns for smaller screens: Year (50px) | Title (rest) */
        grid-template-columns: 50px 1fr;
        padding: 0.8rem 1rem; /* Reduced padding */
        font-size: 0.9rem; /* Reduced font size */
    }

    .publication-item {
        /* Adjust columns for smaller screens: Year (50px) | Content (rest) */
        grid-template-columns: 50px 1fr;
        padding: 0.8rem 1rem; /* Reduced padding */
        gap: 0.8rem; /* Reduced gap */
    }

    .pub-year {
        font-size: 0.85rem; /* Further reduced year font size */
    }

    .pub-title {
        font-size: 0.95rem; /* Further reduced title font size */
    }

    .pub-authors,
    .pub-venue {
        font-size: 0.85rem; /* Further reduced authors/venue font size */
    }
}

@media (max-width: 480px) {
    .publication-header {
        /* On very small screens, hide year header, title takes full width */
        grid-template-columns: 1fr;
        padding: 0.7rem 0.8rem;
        font-size: 0.8rem;
    }
    .pub-year-header {
        display: none; /* Hide year header on smallest screens */
    }

    .publication-item {
        /* On very small screens, hide year column, content takes full width */
        grid-template-columns: 1fr;
        padding: 0.7rem 0.8rem;
        gap: 0.5rem;
    }
    .pub-year {
        display: none; /* Hide year in item on smallest screens */
    }

    .pub-content {
        gap: 0.15rem; /* Even tighter spacing */
    }
}

/* Contact Section */
.contact-section {
    padding: var(--section-padding);
    background: var(--gray-50);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: 4rem;
    max-width: 1000px;
    margin: 0 auto;
}

.contact-text p {
    font-size: 1.125rem;
    color: var(--gray-600);
    margin-bottom: 2rem;
    line-height: 1.6;
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.contact-method {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
    background: var(--white);
    border-radius: 12px;
    text-decoration: none;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
}

.contact-method:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.method-icon {
    width: 50px;
    height: 50px;
    border-radius: 10px;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 1.25rem;
}

.method-text {
    display: flex;
    flex-direction: column;
}

.method-label {
    font-size: 0.875rem;
    color: var(--gray-500);
    font-weight: 500;
}

.method-value {
    font-size: 1rem;
    color: var(--gray-900);
    font-weight: 600;
}

.cta-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
    text-align: center;
}

.cta-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 0.5rem;
}

.cta-card p {
    color: var(--gray-600);
    margin-bottom: 1.5rem;
}

.cta-actions {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

/* Footer */
.footer {
    background: var(--gray-900);
    color: var(--gray-300);
    padding: 3rem 0 1rem;
    margin-top: auto;
}

.footer-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: var(--container-padding);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 3rem;
    margin-bottom: 2rem;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
    cursor: pointer;
}

.footer-logo .logo-text {
    color: var(--white);
}

.footer-text {
    color: var(--gray-400);
    line-height: 1.6;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
}

.footer-section h4 {
    color: var(--white);
    font-weight: 600;
    margin-bottom: 1rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: var(--gray-400);
    text-decoration: none;
    transition: color 0.3s ease;
    cursor: pointer;
}

.footer-section a:hover {
    color: var(--primary-light);
}

.footer-bottom {
    border-top: 1px solid var(--gray-800);
    padding-top: 1rem;
    text-align: center;
    color: var(--gray-500);
}

/* Modal Styles - Updated for PDF Viewer */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    z-index: 1000;
    backdrop-filter: blur(5px);
}

.modal-content {
    position: relative;
    background: var(--white);
    margin: 2% auto;
    border-radius: 16px;
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    max-width: 400px;
    width: 90%;
}

/* PDF Modal Specific Styles */
.pdf-modal {
    width: 70% !important;
    height: 90%;
    max-width: none !important;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    border-bottom: 1px solid var(--gray-200);
    background: var(--gradient-primary);
    color: var(--white);
}

.modal-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--white);
    margin: 0;
}

.pdf-controls {
    display: flex;
    align-items: center;
    gap: 15px;
}

.pdf-controls .btn-outline {
    background: transparent;
    color: var(--white);
    border: 2px solid rgba(255, 255, 255, 0.3);
    padding: 8px 16px;
    font-size: 0.875rem;
}

.pdf-controls .btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.5);
    color: var(--white);
    transform: translateY(-1px);
}

.modal-close {
    background: none;
    border: none;
    color: var(--white);
    font-size: 2rem;
    cursor: pointer;
    padding: 0;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: background-color 0.3s ease;
}

.modal-close:hover {
    background: rgba(255, 255, 255, 0.2);
}

.modal-body {
    padding: 1.5rem;
}

.pdf-body {
    padding: 0;
    height: calc(90vh - 80px);
}

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

.pdf-container iframe {
    border: none;
    display: block;
    width: 100%;
    height: 100%;
}

.pdf-fallback {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    background-color: var(--gray-50);
}

.fallback-content {
    text-align: center;
    padding: 40px;
}

.fallback-content i {
    font-size: 4rem;
    color: var(--error);
    margin-bottom: 20px;
}

.fallback-content h4 {
    margin-bottom: 10px;
    color: var(--gray-900);
}

.fallback-content p {
    color: var(--gray-600);
    margin-bottom: 30px;
}

.resume-options {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-top: 1rem;
}

.resume-option {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    border: 2px solid var(--gray-200);
    border-radius: 8px;
    text-decoration: none;
    color: var(--gray-700);
    transition: all 0.3s ease;
}

.resume-option:hover {
    border-color: var(--primary-blue);
    background: var(--gray-50);
}

.resume-option i {
    font-size: 1.5rem;
    color: var(--primary-blue);
}

.resume-option span {
    font-weight: 500;
}

.resume-option small {
    color: var(--gray-500);
    font-size: 0.875rem;
}

/* Page Navigation Buttons */
.page-nav {
    position: fixed;
    bottom: 30px;
    right: 30px;
    display: flex;
    gap: 10px;
    z-index: 100;
}

.page-nav-btn {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--gradient-primary);
    color: var(--white);
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    transition: all 0.3s ease;
}

.page-nav-btn:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-xl);
}

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

/* Page Indicators */
.page-indicators {
    position: fixed;
    right: 30px;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: 10px;
    z-index: 100;
}

.page-indicator {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--gray-300);
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

.page-indicator.active {
    background: var(--primary-blue);
    transform: scale(1.3);
}

.page-indicator:hover {
    background: var(--primary-light);
    transform: scale(1.2);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        gap: 3rem;
        text-align: center;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
        gap: 3rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .pdf-modal {
        width: 85% !important;
    }
    
    .page-nav {
        bottom: 20px;
        right: 20px;
    }
    
    .page-indicators {
        right: 20px;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: 2rem;
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .title-main {
        font-size: 2.5rem;
    }
    
    .title-gradient {
        font-size: 1.5rem;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .about-intro {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .research-grid {
        grid-template-columns: 1fr;
    }
    
    .publication-item {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .pub-year {
        text-align: left;
        width: fit-content;
    }
    
    .contact-methods {
        gap: 0.75rem;
    }
    
    .contact-method {
        padding: 1rem;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .cta-actions {
        gap: 0.75rem;
    }
    
    .pdf-modal {
        width: 95% !important;
        height: 85%;
        margin: 5% auto;
    }
    
    .modal-header {
        padding: 15px 20px;
    }
    
    .modal-header h3 {
        font-size: 1.1rem;
    }
    
    .pdf-controls {
        gap: 10px;
    }
    
    .pdf-controls .btn-outline {
        padding: 6px 12px;
        font-size: 0.8rem;
    }
    
    .page-nav {
        bottom: 15px;
        right: 15px;
        flex-direction: column;
    }
    
    .page-nav-btn {
        width: 45px;
        height: 45px;
        font-size: 1rem;
    }
    
    .page-indicators {
        right: 15px;
        gap: 8px;
    }
    
    .page-indicator {
        width: 10px;
        height: 10px;
    }
}

@media (max-width: 480px) {
    :root {
        --section-padding: 60px 0;
        --container-padding: 0 16px;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .title-main {
        font-size: 2rem;
    }
    
    .hero-badge {
        font-size: 0.75rem;
        padding: 6px 12px;
    }
    
    .hero-stats {
        gap: 1rem;
    }
    
    .stat-number {
        font-size: 1.5rem;
    }
    
    .btn {
        padding: 10px 20px;
        font-size: 0.875rem;
    }
    
    .research-card,
    .cta-card {
        padding: 1.5rem;
    }
    
    .modal-content {
        margin: 1rem;
        width: calc(100% - 2rem);
    }
    
    .pdf-modal {
        width: calc(100% - 1rem) !important;
        height: calc(100% - 2rem);
        margin: 1rem auto;
    }
    
    .page-nav {
        bottom: 10px;
        right: 10px;
    }
    
    .page-nav-btn {
        width: 40px;
        height: 40px;
        font-size: 0.9rem;
    }
    
    .page-indicators {
        right: 10px;
    }
}