/* ===================================
   CSS Variables & Theme
   =================================== */
:root {
    /* Color Palette - Scientific/Tech Theme */
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary-color: #0891b2;
    --accent-color: #06b6d4;

    /* Neutral Colors */
    --dark-bg: #0f172a;
    --dark-bg-alt: #1e293b;
    --light-bg: #f8fafc;
    --light-bg-alt: #f1f5f9;
    --white: #ffffff;

    /* Text Colors */
    --text-primary: #1e293b;
    --text-secondary: #475569;
    --text-light: #64748b;
    --text-white: #f8fafc;

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #2563eb 0%, #0891b2 100%);
    --gradient-hero: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #334155 100%);

    /* Spacing */
    --section-padding: 80px 20px;
    --container-max-width: 1200px;

    /* Typography */
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* 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: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-main);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* ===================================
   Typography
   =================================== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    color: var(--text-primary);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
    margin-bottom: 1rem;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--primary-dark);
}

.lead {
    font-size: 1.25rem;
    font-weight: 400;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

/* ===================================
   Utility Classes
   =================================== */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 20px;
}

.section {
    padding: var(--section-padding);
}

.section-alt {
    background: var(--light-bg);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    position: relative;
    display: inline-block;
    width: 100%;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

/* ===================================
   Navigation
   =================================== */
#navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.nav-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo a {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--white);
    transition: color var(--transition-fast);
}

.logo a:hover {
    color: var(--accent-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    color: var(--text-white);
    font-weight: 500;
    transition: color var(--transition-fast);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-color);
    transition: width var(--transition-normal);
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--white);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    min-height: 100vh;
    background: var(--gradient-hero);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding-top: 70px;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        radial-gradient(circle at 20% 50%, rgba(37, 99, 235, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(8, 145, 178, 0.1) 0%, transparent 50%);
}

.hero-content {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 4rem;
    align-items: center;
    max-width: var(--container-max-width);
    padding: 0 20px;
}

.hero-title {
    font-size: 3.5rem;
    color: var(--white);
    margin-bottom: 1rem;
    animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
    font-size: 1.75rem;
    color: var(--accent-color);
    margin-bottom: 1.5rem;
    font-weight: 400;
    animation: fadeInUp 0.8s ease 0.2s backwards;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-white);
    opacity: 0.9;
    margin-bottom: 2rem;
    max-width: 600px;
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    animation: fadeInUp 0.8s ease 0.6s backwards;
    flex-wrap: wrap;
}

.btn {
    padding: 12px 32px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1rem;
    transition: all var(--transition-normal);
    cursor: pointer;
    border: none;
    display: inline-block;
}

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

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

.btn-secondary {
    background: transparent;
    color: var(--white);
    border: 2px solid var(--accent-color);
}

.btn-secondary:hover {
    background: var(--accent-color);
    color: var(--dark-bg);
}

.hero-social {
    display: flex;
    gap: 1.5rem;
    animation: fadeInUp 0.8s ease 0.8s backwards;
}

.hero-social a {
    width: 45px;
    height: 45px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    color: var(--white);
    font-size: 1.25rem;
    transition: all var(--transition-normal);
    backdrop-filter: blur(10px);
}

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

/* DNA Animation */
.hero-visual {
    position: relative;
    height: 400px;
    animation: fadeInRight 1s ease 0.5s backwards;
}

.dna-animation {
    position: relative;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* DNA Double Helix - Improved Visible Animation */
.dna-strand {
    position: absolute;
    width: 100%;
    height: 100%;
}

.dna-strand::before {
    content: '';
    position: absolute;
    width: 12px;
    height: 12px;
    background: radial-gradient(circle, var(--accent-color) 0%, rgba(6, 182, 212, 0.4) 70%, transparent 100%);
    border-radius: 50%;
    box-shadow:
        0 0 20px rgba(6, 182, 212, 0.9),
        0 0 40px rgba(6, 182, 212, 0.6),
        0 0 60px rgba(6, 182, 212, 0.3);
}

.strand-left::before {
    animation: strandLeftPath 5s ease-in-out infinite;
}

.strand-right::before {
    animation: strandRightPath 5s ease-in-out infinite;
}

/* DNA Base Pairs - More visible */
.base-pair {
    position: absolute;
    left: 50%;
    height: 5px;
    background: linear-gradient(90deg,
        var(--accent-color) 0%,
        rgba(59, 130, 246, 0.8) 50%,
        var(--primary-light) 100%
    );
    border-radius: 3px;
    transform-origin: center center;
    box-shadow:
        0 0 15px rgba(59, 130, 246, 0.7),
        0 0 30px rgba(59, 130, 246, 0.4);
}

/* 12 base pairs synchronized with strand positions */
.bp1  { top: 0%;  animation: basePairWidth1 5s ease-in-out infinite, rotatePair 5s ease-in-out infinite; }
.bp2  { top: 8%;  animation: basePairWidth2 5s ease-in-out infinite, rotatePair 5s ease-in-out infinite; animation-delay: -0.42s; }
.bp3  { top: 16%; animation: basePairWidth3 5s ease-in-out infinite, rotatePair 5s ease-in-out infinite; animation-delay: -0.84s; }
.bp4  { top: 25%; animation: basePairWidth4 5s ease-in-out infinite, rotatePair 5s ease-in-out infinite; animation-delay: -1.26s; }
.bp5  { top: 33%; animation: basePairWidth5 5s ease-in-out infinite, rotatePair 5s ease-in-out infinite; animation-delay: -1.68s; }
.bp6  { top: 41%; animation: basePairWidth6 5s ease-in-out infinite, rotatePair 5s ease-in-out infinite; animation-delay: -2.1s; }
.bp7  { top: 50%; animation: basePairWidth7 5s ease-in-out infinite, rotatePair 5s ease-in-out infinite; animation-delay: -2.52s; }
.bp8  { top: 58%; animation: basePairWidth8 5s ease-in-out infinite, rotatePair 5s ease-in-out infinite; animation-delay: -2.94s; }
.bp9  { top: 66%; animation: basePairWidth9 5s ease-in-out infinite, rotatePair 5s ease-in-out infinite; animation-delay: -3.36s; }
.bp10 { top: 75%; animation: basePairWidth10 5s ease-in-out infinite, rotatePair 5s ease-in-out infinite; animation-delay: -3.78s; }
.bp11 { top: 83%; animation: basePairWidth11 5s ease-in-out infinite, rotatePair 5s ease-in-out infinite; animation-delay: -4.2s; }
.bp12 { top: 91%; animation: basePairWidth12 5s ease-in-out infinite, rotatePair 5s ease-in-out infinite; animation-delay: -4.62s; }

/* Left strand - smooth helical path */
@keyframes strandLeftPath {
    0%   { left: calc(50% - 50px); top: 0%; }
    8%   { left: calc(50% - 45px); top: 8%; }
    16%  { left: calc(50% - 30px); top: 16%; }
    25%  { left: calc(50%); top: 25%; }
    33%  { left: calc(50% + 30px); top: 33%; }
    41%  { left: calc(50% + 45px); top: 41%; }
    50%  { left: calc(50% + 50px); top: 50%; }
    58%  { left: calc(50% + 45px); top: 58%; }
    66%  { left: calc(50% + 30px); top: 66%; }
    75%  { left: calc(50%); top: 75%; }
    83%  { left: calc(50% - 30px); top: 83%; }
    91%  { left: calc(50% - 45px); top: 91%; }
    100% { left: calc(50% - 50px); top: 100%; }
}

/* Right strand - opposite phase */
@keyframes strandRightPath {
    0%   { left: calc(50% + 50px); top: 0%; }
    8%   { left: calc(50% + 45px); top: 8%; }
    16%  { left: calc(50% + 30px); top: 16%; }
    25%  { left: calc(50%); top: 25%; }
    33%  { left: calc(50% - 30px); top: 33%; }
    41%  { left: calc(50% - 45px); top: 41%; }
    50%  { left: calc(50% - 50px); top: 50%; }
    58%  { left: calc(50% - 45px); top: 58%; }
    66%  { left: calc(50% - 30px); top: 66%; }
    75%  { left: calc(50%); top: 75%; }
    83%  { left: calc(50% + 30px); top: 83%; }
    91%  { left: calc(50% + 45px); top: 91%; }
    100% { left: calc(50% + 50px); top: 100%; }
}

/* Base pairs rotate in 3D */
@keyframes rotatePair {
    0% {
        transform: translateX(-50%) rotateX(0deg) scale(1);
        opacity: 1;
    }
    25% {
        transform: translateX(-50%) rotateX(90deg) scale(0.25);
        opacity: 0.3;
    }
    50% {
        transform: translateX(-50%) rotateX(180deg) scale(1);
        opacity: 1;
    }
    75% {
        transform: translateX(-50%) rotateX(270deg) scale(0.25);
        opacity: 0.3;
    }
    100% {
        transform: translateX(-50%) rotateX(360deg) scale(1);
        opacity: 1;
    }
}

/* Synchronized width animations for each base pair */
/* bp1 at 0% - starts at max width, shrinks to 0 at 25%, back to max at 50%, etc */
@keyframes basePairWidth1 {
    0%   { width: 100px; }
    25%  { width: 0px; }
    50%  { width: 100px; }
    75%  { width: 0px; }
    100% { width: 100px; }
}

/* bp2 at 8% - slightly offset from bp1 */
@keyframes basePairWidth2 {
    0%   { width: 90px; }
    17%  { width: 20px; }
    33%  { width: 90px; }
    67%  { width: 90px; }
    83%  { width: 20px; }
    100% { width: 90px; }
}

/* bp3 at 16% - more offset */
@keyframes basePairWidth3 {
    0%   { width: 60px; }
    9%   { width: 70px; }
    25%  { width: 100px; }
    41%  { width: 70px; }
    59%  { width: 70px; }
    75%  { width: 100px; }
    91%  { width: 70px; }
    100% { width: 60px; }
}

/* bp4 at 25% - at the crossing point */
@keyframes basePairWidth4 {
    0%   { width: 0px; }
    25%  { width: 100px; }
    50%  { width: 0px; }
    75%  { width: 100px; }
    100% { width: 0px; }
}

/* bp5 at 33% - opposite pattern to bp3 */
@keyframes basePairWidth5 {
    0%   { width: 60px; }
    17%  { width: 70px; }
    33%  { width: 90px; }
    50%  { width: 60px; }
    67%  { width: 90px; }
    83%  { width: 70px; }
    100% { width: 60px; }
}

/* bp6 at 41% - opposite pattern to bp2 */
@keyframes basePairWidth6 {
    0%   { width: 90px; }
    25%  { width: 70px; }
    41%  { width: 20px; }
    50%  { width: 0px; }
    59%  { width: 20px; }
    75%  { width: 70px; }
    100% { width: 90px; }
}

/* bp7 at 50% - opposite to bp1 */
@keyframes basePairWidth7 {
    0%   { width: 100px; }
    25%  { width: 0px; }
    50%  { width: 100px; }
    75%  { width: 0px; }
    100% { width: 100px; }
}

/* bp8 at 58% - mirror of bp6 */
@keyframes basePairWidth8 {
    0%   { width: 90px; }
    25%  { width: 70px; }
    41%  { width: 20px; }
    50%  { width: 0px; }
    59%  { width: 20px; }
    75%  { width: 70px; }
    100% { width: 90px; }
}

/* bp9 at 66% - mirror of bp5 */
@keyframes basePairWidth9 {
    0%   { width: 60px; }
    17%  { width: 70px; }
    33%  { width: 90px; }
    50%  { width: 60px; }
    67%  { width: 90px; }
    83%  { width: 70px; }
    100% { width: 60px; }
}

/* bp10 at 75% - at the second crossing point */
@keyframes basePairWidth10 {
    0%   { width: 0px; }
    25%  { width: 100px; }
    50%  { width: 0px; }
    75%  { width: 100px; }
    100% { width: 0px; }
}

/* bp11 at 83% - mirror of bp3 */
@keyframes basePairWidth11 {
    0%   { width: 60px; }
    9%   { width: 70px; }
    25%  { width: 100px; }
    41%  { width: 70px; }
    59%  { width: 70px; }
    75%  { width: 100px; }
    91%  { width: 70px; }
    100% { width: 60px; }
}

/* bp12 at 91% - mirror of bp2 */
@keyframes basePairWidth12 {
    0%   { width: 90px; }
    17%  { width: 20px; }
    33%  { width: 90px; }
    67%  { width: 90px; }
    83%  { width: 20px; }
    100% { width: 90px; }
}

.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

.scroll-indicator a {
    color: var(--white);
    font-size: 2rem;
    opacity: 0.7;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
    40% { transform: translateX(-50%) translateY(-10px); }
    60% { transform: translateX(-50%) translateY(-5px); }
}

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

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* ===================================
   About Section
   =================================== */
.about-content {
    max-width: 900px;
    margin: 0 auto;
}

.about-text p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.about-highlights {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.highlight-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1.5rem;
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

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

.highlight-item i {
    font-size: 2rem;
    color: var(--primary-color);
}

.highlight-item h4 {
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.highlight-item p {
    margin: 0;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* ===================================
   Experience Timeline
   =================================== */
.timeline {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    padding-left: 40px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--gradient-primary);
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
}

.timeline-marker {
    position: absolute;
    left: -48px;
    top: 0;
    width: 20px;
    height: 20px;
    background: var(--primary-color);
    border: 4px solid var(--light-bg);
    border-radius: 50%;
    box-shadow: var(--shadow-md);
}

.timeline-content {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.timeline-content:hover {
    box-shadow: var(--shadow-xl);
    transform: translateX(5px);
}

.timeline-date {
    display: inline-block;
    background: var(--gradient-primary);
    color: var(--white);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.timeline-content h3 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.timeline-content h4 {
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.location {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.timeline-content ul {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}

.timeline-content li {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1rem;
}

.tech-tags span {
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary-color);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

/* ===================================
   Skills Section
   =================================== */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.skill-category {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

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

.skill-icon {
    width: 60px;
    height: 60px;
    background: var(--gradient-primary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.skill-icon i {
    font-size: 1.75rem;
    color: var(--white);
}

.skill-category h3 {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.skill-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.skill-tag {
    background: var(--light-bg-alt);
    color: var(--text-secondary);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.skill-tag:hover {
    background: var(--primary-color);
    color: var(--white);
}

/* ===================================
   Publications Section
   =================================== */
.publications-list {
    max-width: 900px;
    margin: 0 auto 3rem;
}

.publication-item {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: 2rem;
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    margin-bottom: 2rem;
    transition: all var(--transition-normal);
}

.publication-item:hover {
    box-shadow: var(--shadow-xl);
    transform: translateY(-2px);
}

.publication-item.featured {
    border: 2px solid var(--primary-color);
}

.publication-year {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.publication-content h3 {
    color: var(--text-primary);
    margin-bottom: 0.75rem;
    line-height: 1.4;
}

.badge {
    display: inline-block;
    background: var(--gradient-primary);
    color: var(--white);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.authors {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
}

.journal {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.description {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin: 1rem 0;
}

.publication-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    font-weight: 600;
    transition: all var(--transition-fast);
}

.publication-link:hover {
    gap: 0.75rem;
}

.publication-metrics {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-top: 3rem;
}

.metric {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem 2rem;
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow-md);
}

.metric i {
    font-size: 2rem;
    color: var(--primary-color);
}

.metric h4 {
    font-size: 2rem;
    color: var(--text-primary);
    margin: 0;
}

.metric p {
    color: var(--text-secondary);
    margin: 0;
    font-size: 0.9rem;
}

/* ===================================
   Projects Section
   =================================== */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.project-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

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

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

.project-header i {
    font-size: 2rem;
    color: var(--primary-color);
}

.project-header h3 {
    color: var(--text-primary);
}

.project-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    min-height: 80px;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.project-tech span {
    background: var(--light-bg-alt);
    color: var(--text-secondary);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    font-weight: 600;
    transition: all var(--transition-fast);
}

.project-link:hover {
    gap: 0.75rem;
}

/* ===================================
   Contact Section
   =================================== */
.contact-content {
    max-width: 700px;
    margin: 0 auto;
}

.contact-details {
    margin: 2rem 0;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    padding: 1.5rem;
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    margin-bottom: 1.5rem;
    transition: all var(--transition-normal);
}

.contact-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-lg);
}

.contact-item i {
    font-size: 1.75rem;
    color: var(--primary-color);
    margin-top: 0.25rem;
}

.contact-item h4 {
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.contact-item a {
    color: var(--primary-color);
    font-weight: 500;
}

.contact-item p {
    margin: 0;
    color: var(--text-secondary);
}

.social-links {
    margin-top: 3rem;
    text-align: center;
}

.social-links h4 {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.social-icons {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
}

.social-icons a {
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: 50%;
    color: var(--white);
    font-size: 1.5rem;
    transition: all var(--transition-normal);
}

.social-icons a:hover {
    transform: translateY(-5px) scale(1.1);
    box-shadow: var(--shadow-lg);
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--dark-bg);
    padding: 2rem 0;
    text-align: center;
}

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

.footer-content p {
    margin: 0.5rem 0;
    opacity: 0.8;
}

.footer-tagline {
    font-weight: 600;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        gap: 3rem;
    }

    .hero-visual {
        height: 300px;
    }
}

@media (max-width: 768px) {
    html {
        font-size: 14px;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: rgba(15, 23, 42, 0.98);
        width: 100%;
        text-align: center;
        transition: left var(--transition-normal);
        box-shadow: var(--shadow-lg);
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-toggle {
        display: flex;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.5rem;
    }

    .hero-buttons {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .timeline {
        padding-left: 30px;
    }

    .timeline-marker {
        left: -38px;
    }

    .publication-item {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .publication-year {
        font-size: 1.25rem;
    }

    .publication-metrics {
        flex-direction: column;
        gap: 1.5rem;
    }

    .skills-grid {
        grid-template-columns: 1fr;
    }

    .projects-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .section {
        padding: 60px 15px;
    }

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

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

    .hero-subtitle {
        font-size: 1.25rem;
    }

    .about-highlights {
        grid-template-columns: 1fr;
    }
}

/* ===================================
   Accessibility
   =================================== */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* ===================================
   Print Styles
   =================================== */
@media print {
    .nav-toggle,
    .scroll-indicator,
    .hero-social,
    .hero-buttons {
        display: none;
    }

    .section {
        page-break-inside: avoid;
    }
}