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

/* Modern Physics-inspired color palette */
:root {
    /* Primary Colors */
    --primary-dark: #0a0f2c;
    --primary-blue: #1e3a8a;
    --primary-light: #f8fafc;
    
    /* Secondary Colors */
    --accent-purple: #7c3aed;
    --accent-cyan: #06b6d4;
    --accent-orange: #f59e0b;
    --accent-pink: #ec4899;
    
    /* Neutrals */
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-500: #6b7280;
    --gray-700: #374151;
    --gray-900: #111827;
    
    /* Semantic Colors */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    
    /* Spacing Scale */
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    
    /* 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);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Transitions */
    --transition-fast: 0.15s ease-in-out;
    --transition-normal: 0.3s ease-in-out;
    --transition-slow: 0.5s ease-in-out;

    /* Section Background Sequence tokens (WCAG AA with dark text)
       These mirror the palette used in index1.html and are safe fallbacks for other pages. */
    --seq-1: #ffffff;                         /* card white */
    --seq-2: #f8fafc;                         /* surface color */
    --seq-3: rgba(6, 182, 212, 0.08);         /* accent-cyan tint */
    --seq-4: #f3f4f6;                         /* light neutral */
}

/* Base styles */
body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--gray-700);
    background-color: var(--primary-light);
    overflow-x: hidden;
    font-smooth: always;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Smooth transitions for all elements */
* {
    transition: all 0.3s ease-in-out;
}

/* Header Section */
.header {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary-blue) 100%);
    color: var(--primary-light);
    padding: var(--space-lg) 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.profile-info {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
}

.profile-img {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    border: 3px solid var(--accent-cyan);
    object-fit: cover;
    box-shadow: 0 4px 15px rgba(6, 182, 212, 0.3);
    transition: transform var(--transition-normal);
}

.profile-img:hover {
    transform: scale(1.05);
}

.profile-text {
    text-align: left;
}

.name {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-light);
    margin-bottom: 0.25rem;
}

.title {
    font-size: 0.9rem;
    font-weight: 400;
    color: var(--gray-200);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.nav-menu {
    display: flex;
    gap: var(--space-xl);
    align-items: center;
}

.nav-link {
    color: var(--primary-light);
    text-decoration: none;
    font-weight: 500;
    font-size: 1rem;
    position: relative;
    padding: 0.5rem 0;
    transition: color var(--transition-normal);
}

.nav-link:hover {
    color: var(--accent-cyan);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-cyan);
    transition: width var(--transition-normal);
}

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

/* Main Content */
.main {
    margin-top: 100px;
    min-height: 100vh;
}

/* Section Base Styles */
.section {
    padding: var(--space-3xl) 0;
    position: relative;
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp var(--transition-slow) forwards;
}

.section:nth-child(even) {
    background-color: var(--gray-50);
}

.section:nth-child(odd) {
    background-color: var(--primary-light);
}

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--space-3xl);
    color: var(--primary-dark);
    position: relative;
    line-height: 1.2;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--accent-cyan);
    border-radius: var(--radius-sm);
}

/* About Section */
.about-section {
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--gray-50) 100%);
}

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

.about-text {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: var(--space-lg);
    color: var(--gray-700);
}

/* Research Interests Section */
.research-section {
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--gray-50) 100%);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-xl);
    max-width: 1100px;
    margin: 0 auto;
}

.research-card {
    background: var(--primary-light);
    padding: var(--space-xl) var(--space-lg);
    border-radius: var(--radius-xl);
    text-align: center;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--gray-200);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(10px);
}

.research-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-purple), var(--accent-cyan), var(--accent-orange));
}

.research-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-cyan);
}

.research-icon {
    font-size: 3rem;
    margin-bottom: var(--space-lg);
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-blue));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: transform var(--transition-normal);
}

.research-card:hover .research-icon {
    transform: scale(1.1);
}

.research-title {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
    color: var(--primary-dark);
}

.research-description {
    font-size: 1rem;
    line-height: 1.7;
    color: var(--gray-700);
}

/* Publications Section */
.publications-section {
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--gray-50) 100%);
}

.publications-list {
    max-width: 900px;
    margin: 0 auto;
}

.publication-card {
    background: var(--primary-light);
    margin-bottom: var(--space-xl);
    padding: var(--space-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    border-left: 4px solid var(--accent-cyan);
    transition: all var(--transition-normal);
    border: 1px solid var(--gray-200);
}

.publication-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-cyan);
}

.publication-title {
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--primary-dark);
    line-height: 1.3;
}

.publication-journal {
    font-size: 1rem;
    color: var(--accent-cyan);
    margin-bottom: var(--space-md);
    font-style: italic;
}

.publication-abstract {
    font-size: 1.1rem;
    line-height: 1.7;
    margin-bottom: var(--space-lg);
    color: var(--gray-700);
}

.publication-link {
    display: inline-flex;
    align-items: center;
    color: var(--accent-cyan);
    text-decoration: none;
    font-weight: 600;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    background: rgba(6, 182, 212, 0.1);
    transition: all var(--transition-normal);
}

.publication-link:hover {
    background: var(--accent-cyan);
    color: var(--primary-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.publication-link i {
    margin-left: 0.5rem;
    transition: transform var(--transition-normal);
}

.publication-link:hover i {
    transform: translateX(3px);
}

/* Contact Section */
.contact-section {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary-blue) 100%);
    color: var(--primary-light);
}

.contact-content {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.contact-text {
    font-size: 1.1rem;
    line-height: 1.7;
    margin-bottom: var(--space-xl);
    color: var(--gray-200);
}

.contact-details {
    margin-bottom: var(--space-xl);
    text-align: left;
    max-width: 350px;
    margin-left: auto;
    margin-right: auto;
}

.contact-details p {
    margin-bottom: var(--space-md);
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-sm) 0;
}

.contact-details i {
    color: var(--accent-cyan);
    font-size: 1.2rem;
    min-width: 20px;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: var(--space-xl);
    margin-top: var(--space-xl);
}

.social-link {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-light);
    text-decoration: none;
    font-size: 1.2rem;
    transition: all var(--transition-normal);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    position: relative;
    overflow: hidden;
}

.social-link::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left var(--transition-normal);
}

.social-link:hover::before {
    left: 100%;
}

.social-link:hover {
    background: var(--accent-cyan);
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

/* Footer Display Control */
.footer-left {
    display: block;
}

.mobile-footer-header {
    display: none;
}

/* Enhanced Mobile Responsiveness */
@media (max-width: 768px) {
    .footer-left {
        display: none !important;
    }

    .mobile-footer-header {
        display: block !important;
    }

    .mobile-footer-header {
        display: block;
        text-align: center;
        color: white;
        font-family: 'Inter', sans-serif;
        padding: 1.5rem 1rem;
        background: rgba(0, 0, 0, 0.3);
        border-radius: 15px;
        margin-bottom: 1rem;
        backdrop-filter: blur(10px);
    }

    .mobile-footer-header h3 {
        font-size: 1.8rem;
        font-weight: 700;
        margin-bottom: 0.5rem;
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 0.5rem;
    }

    .mobile-footer-header h3 i {
        color: #fbbf24;
        font-size: 1.6rem;
    }

    .mobile-footer-header p {
        font-size: 1rem;
        margin: 0.3rem 0;
        line-height: 1.4;
    }

    .mobile-footer-header p:first-of-type {
        font-weight: 600;
        color: #fbbf24;
    }

    .mobile-footer-header p:nth-of-type(2) {
        font-size: 0.95rem;
        color: rgba(255, 255, 255, 0.9);
    }

    .mobile-footer-header p:nth-of-type(3) {
        font-size: 0.9rem;
        color: rgba(255, 255, 255, 0.85);
    }

    .mobile-footer-header p:nth-of-type(4) {
        font-size: 0.85rem;
        color: rgba(255, 255, 255, 0.8);
    }

    .mobile-footer-header p:nth-of-type(5) {
        font-size: 0.8rem;
        color: rgba(255, 255, 255, 0.75);
        border-top: 1px solid rgba(255, 255, 255, 0.2);
        padding-top: 0.5rem;
        margin-top: 0.5rem;
    }


    .header-content {
        flex-direction: column;
        padding: var(--space-md);
        text-align: center;
    }

    .profile-info {
        margin-bottom: var(--space-md);
        gap: var(--space-md);
    }

    .nav-menu {
        flex-wrap: wrap;
        justify-content: center;
        gap: var(--space-md);
    }

    .section {
        padding: var(--space-2xl) 0;
    }

    .section-title {
        font-size: 2rem;
    }

    .research-grid {
        grid-template-columns: 1fr;
        gap: var(--space-md);
    }

    .about-text,
    .research-description,
    .publication-abstract {
        font-size: 1rem;
    }

    .publication-card {
        padding: var(--space-md);
    }

    .social-links {
        gap: var(--space-md);
    }

    .social-link {
        width: 45px;
        height: 45px;
        font-size: 1.1rem;
    }

    /* Footer Mobile Optimization - Display exact sequence */
    .footer-content {
        flex-direction: column;
        gap: 0.5rem;
        text-align: center;
    }
    
    .footer-left,
    .footer-right {
        width: 100%;
        display: flex;
        flex-direction: column;
        align-items: center;
    }
    
    /* Ensure exact sequence: CPS-2026, 5th Conference..., Dates, Organized by, Copyright */
    .footer-left {
        order: 1;
    }
    
    .footer-right {
        order: 2;
    }
    
    .footer-left h3 {
        font-size: 1.5rem;
        margin-bottom: 0.25rem;
        order: 1;
    }
    
    .footer-conference {
        font-size: 1.1rem !important;
        margin: 0.25rem 0 !important;
        order: 2;
    }
    
    .footer-dates {
        font-size: 0.9rem !important;
        margin: 0.25rem 0 !important;
        order: 3;
    }
    
    .footer-organized {
        font-size: 0.95rem !important;
        margin: 0.25rem 0 !important;
        order: 4;
    }
    
    .footer-copyright {
        font-size: 0.8rem !important;
        margin: 0.25rem 0 !important;
        order: 5;
    }
}

@media (max-width: 480px) {
    .section-title {
        font-size: 1.8rem;
    }

    .profile-img {
        width: 50px;
        height: 50px;
    }

    .name {
        font-size: 1.3rem;
    }

    .title {
        font-size: 0.8rem;
    }

    .section {
        padding: var(--space-xl) 0;
    }
}

/* Additional Breakpoints */
@media (max-width: 360px) {
    .section-title {
        font-size: 1.6rem;
    }

    .name {
        font-size: 1.2rem;
    }

    .publication-card,
    .research-card {
        padding: var(--space-md);
    }
}

@media (min-width: 1024px) {
    .research-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (min-width: 1200px) {
    .research-grid {
        grid-template-columns: repeat(4, 1fr);
        max-width: 1200px;
    }
}

/* Mobile Toggle Button */
.mobile-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--primary-light);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--radius-sm);
    transition: background-color var(--transition-normal);
}

.mobile-toggle:hover {
    background: rgba(255, 255, 255, 0.1);
}

.mobile-toggle.active {
    background: rgba(255, 255, 255, 0.2);
}

.nav-menu.active {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-xl) 0;
    background: rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    margin: var(--space-sm);
}

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--accent-cyan);
    color: var(--primary-light);
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    z-index: 999;
    box-shadow: var(--shadow-md);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--primary-blue);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* Enhanced Mobile Toggle Animation */
@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.nav-menu.active {
    animation: slideDown var(--transition-normal) forwards;
}

/* Research Progress Bars */
.research-progress {
    margin-top: var(--space-md);
    width: 100%;
    height: 8px;
    background: var(--gray-200);
    border-radius: var(--radius-sm);
    overflow: hidden;
}

.research-progress::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    background: linear-gradient(90deg, var(--accent-purple), var(--accent-cyan));
    border-radius: var(--radius-sm);
    transition: width var(--transition-normal);
}

.research-card:hover .research-progress::after {
    animation: progressFill 1s ease-in-out forwards;
}

@keyframes progressFill {
    from {
        width: 0;
    }
    to {
        width: 70%; /* Example progress */
    }
}

/* Contact Form Styles */
.contact-form {
    background: rgba(255, 255, 255, 0.1);
    padding: var(--space-xl);
    border-radius: var(--radius-xl);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    margin-top: var(--space-xl);
}

.form-group {
    margin-bottom: var(--space-md);
}

.form-group label {
    display: block;
    margin-bottom: var(--space-sm);
    color: var(--primary-light);
    font-weight: 500;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: var(--space-md);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.1);
    color: var(--primary-light);
    font-family: inherit;
    transition: border-color var(--transition-normal);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-cyan);
    box-shadow: 0 0 0 2px rgba(6, 182, 212, 0.2);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.submit-btn {
    background: var(--accent-cyan);
    color: var(--primary-light);
    border: none;
    padding: var(--space-md) var(--space-xl);
    border-radius: var(--radius-sm);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    width: 100%;
}

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

/* Improved Scrollbar Styling */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: var(--gray-50);
}

::-webkit-scrollbar-thumb {
    background: var(--accent-cyan);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-blue);
}

/* Dark Mode Support */
@media (prefers-color-scheme: dark) {
    :root {
        --primary-light: #0f172a;
        --gray-50: #1e293b;
        --gray-100: #334155;
        --gray-200: #475569;
        --gray-700: #f8fafc;
    }
    
    .research-card,
    .publication-card {
/* Modern Single-Column Footer Design */
.footer-content {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
}

.footer-left {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.footer-left h3 {
    font-size: 1.6rem;
    margin-bottom: 0.5rem;
    color: white;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-family: 'Playfair Display', serif;
    font-weight: 700;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.footer-left p:nth-child(4) {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.85);
    margin: 0.4rem 0;
    font-weight: 400;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 0.4rem;
}

.footer-left p:nth-child(5) {
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.8);
    margin-top: 0.4rem;
    font-weight: 300;
    font-style: italic;
}


/* Modern Mobile Footer - Stack columns */
@media (max-width: 768px) {
    .footer-content {
        gap: 1rem;
        text-align: center;
        padding: 1.5rem 0;
    }
    
    .footer-left {
        align-items: center;
        order: 1;
    }
    
    .footer-left h3 {
        font-size: 1.4rem;
        margin-bottom: 0.4rem;
        gap: 0.5rem;
    }
    
    .footer-left p:nth-child(4) {
        font-size: 0.8rem;
        margin: 0.4rem 0;
        border-top: 1px solid rgba(255, 255, 255, 0.1);
        padding-top: 0.4rem;
    }
    
    .footer-left p:nth-child(5) {
        font-size: 0.75rem;
        margin-top: 0.4rem;
        font-weight: 300;
        font-style: italic;
    }
    
    /* Add subtle animation on mobile */
    .footer-left > * {
        animation: fadeInUp 0.6s ease forwards;
    }
    
    .footer-left h3 {
        animation-delay: 0.1s;
    }
    
    .footer-left p:first-child {
        animation-delay: 0.2s;
    }
    
    .footer-left p:nth-child(3) {
        animation-delay: 0.3s;
    }
    
    .footer-left p:nth-child(4) {
        animation-delay: 0.4s;
    }
    
    .footer-left p:nth-child(5) {
        animation-delay: 0.5s;
    }
}

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

/* Enhanced desktop footer */
@media (min-width: 769px) {
    .footer-content {
        max-width: 800px;
        margin: 0 auto;
    }
    
    .footer-right p:first-child {
        transition: all 0.3s ease;
    }
    
    .footer-right p:first-child:hover {
        background: rgba(255, 255, 255, 0.2);
        transform: translateY(-2px);
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    }
}
        background: var(--gray-800);
        border-color: var(--gray-600);
    }
    
    .contact-section {
        background: linear-gradient(135deg, #1e3a8a, #3b82f6);
    }
}

/* Footer Mobile Optimization */
.footer-conference {
    font-size: 1.1rem !important;
    margin: 0.5rem 0 !important;
    line-height: 1.3 !important;
}

.footer-dates {
    font-size: 0.9rem !important;
    margin: 0.5rem 0 !important;
    opacity: 0.9 !important;
    font-weight: 400 !important;
}

.footer-organized {
    font-size: 0.95rem !important;
    margin: 0.5rem 0 !important;
    font-weight: 500 !important;
}

.footer-copyright {
    font-size: 0.85rem !important;
    margin: 0.5rem 0 !important;
    opacity: 0.8 !important;
    font-weight: 400 !important;
}

/* added by me  */