/* ===================================
   CSS Variables & Reset
   =================================== */
:root {
    /* Light Mode Colors - White/Orange */
    --primary-color: #9a3412;
    --primary-dark: #7c2d12;
    --primary-light: #c2410c;
    --secondary-color: #92400e;
    --accent-color: #c2410c;
    --accent-secondary: #ea580c;
    
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-light: #94a3b8;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-dark: #0f172a;
    --bg-gradient: linear-gradient(135deg, #f97316 0%, #fb923c 100%);
    
    --border-color: #e2e8f0;
    --border-light: #f1f5f9;
    
    /* Enhanced 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);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    --shadow-colored: 0 10px 40px -10px rgba(99, 102, 241, 0.3);
    --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.3);
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-heading: 'Playfair Display', Georgia, serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 5rem;
    
    /* Border Radius */
    --radius-sm: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-2xl: 2rem;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: 500ms cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

/* Dark Mode Colors - Black/Cyan/Light Blue */
body.dark-mode {
    --primary-color: #0e7490;
    --primary-dark: #155e75;
    --primary-light: #0891b2;
    --secondary-color: #164e63;
    --accent-color: #0891b2;
    --accent-secondary: #0e7490;
    
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-light: #94a3b8;
    
    --bg-primary: #0a0a0a;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #262626;
    --bg-dark: #000000;
    --bg-gradient: linear-gradient(135deg, #06b6d4 0%, #0ea5e9 100%);
    
    --border-color: #334155;
    --border-light: #1e293b;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.5);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.5), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 10px 10px -5px rgba(0, 0, 0, 0.2);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.7);
    --shadow-colored: 0 10px 40px -10px rgba(6, 182, 212, 0.6);
    --shadow-glow: 0 0 30px rgba(6, 182, 212, 0.5);
}

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

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

body {
    font-family: var(--font-primary);
    color: var(--text-primary);
    line-height: 1.6;
    background-color: var(--bg-primary);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Glass morphism utility */
.glass {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

/* Gradient text utility */
.gradient-text {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ===================================
   Typography
   =================================== */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
}

h1 { font-size: 3.5rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 1.875rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: 1rem;
}

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

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

.lead {
    font-size: 1.25rem;
    font-weight: 400;
    line-height: 1.8;
    color: var(--text-secondary);
}

/* ===================================
   Container & Layout
   =================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.section {
    padding: var(--spacing-3xl) 0;
    position: relative;
    background: var(--bg-primary);
}

.section:nth-child(even) {
    background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
}

.section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 90%;
    max-width: 1400px;
    height: 1px;
    background: linear-gradient(90deg, transparent 0%, var(--border-color) 50%, transparent 100%);
    opacity: 0.5;
}

.section-title {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    position: relative;
    font-size: 2.75rem;
    font-weight: 800;
    letter-spacing: -0.02em;
}

.section-title::after {
    content: '';
    display: block;
    width: 100px;
    height: 5px;
    background: linear-gradient(90deg, var(--primary-color) 0%, var(--accent-color) 100%);
    margin: var(--spacing-md) auto 0;
    border-radius: var(--radius-full);
    box-shadow: 0 0 20px rgba(99, 102, 241, 0.4);
}

.section-title::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.05) 0%, transparent 70%);
    z-index: -1;
    pointer-events: none;
}

.subsection-title {
    font-size: 1.75rem;
    margin: var(--spacing-xl) 0 var(--spacing-lg);
    color: var(--text-primary);
}

/* ===================================
   Header & Navigation
   =================================== */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    z-index: 1000;
    transition: all var(--transition-base);
}

body.dark-mode .site-header {
    background: rgba(10, 10, 10, 0.9);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
    border-bottom: 1px solid rgba(8, 145, 178, 0.15);
}

.site-header.scrolled {
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-md);
}

body.dark-mode .site-header.scrolled {
    background: rgba(10, 10, 10, 0.95);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.4);
}

.navbar {
    padding: 1.25rem 0;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    font-family: var(--font-heading);
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: var(--transition-base);
}

body.dark-mode .logo {
    background: linear-gradient(135deg, #06b6d4 0%, #22d3ee 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo:hover {
    transform: scale(1.05);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 0.5rem;
    align-items: center;
}

.nav-item {
    position: relative;
}

.submenu-toggle {
    border: none;
    background: transparent;
    font: inherit;
    color: inherit;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.35rem;
}

.has-submenu.child-active > .submenu-toggle {
    color: var(--primary-color);
}

body.dark-mode .has-submenu.child-active > .submenu-toggle {
    color: #06b6d4;
}

.submenu-icon {
    display: inline-flex;
    font-size: 0.75rem;
    transition: transform var(--transition-base);
}

.has-submenu.open .submenu-icon,
.has-submenu:hover .submenu-icon,
.has-submenu.child-active .submenu-icon {
    transform: rotate(180deg);
}

.submenu {
    position: absolute;
    top: calc(100% + 0.5rem);
    left: 0;
    min-width: 200px;
    padding: 0.75rem;
    border-radius: var(--radius-xl);
    background: white;
    box-shadow: var(--shadow-lg);
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    opacity: 0;
    pointer-events: none;
    transform: translateY(10px);
    transition: var(--transition-base);
    border: 1px solid var(--border-light);
    z-index: 10;
}

body.dark-mode .submenu {
    background: var(--bg-secondary);
    border-color: rgba(8, 145, 178, 0.2);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.45);
}

.has-submenu:hover .submenu,
.has-submenu:focus-within .submenu,
.has-submenu.open .submenu {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0);
}

.submenu-link {
    display: block;
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-primary);
    transition: var(--transition-base);
}

body.dark-mode .submenu-link {
    color: #e5e5e5;
}

.submenu-link:hover,
.submenu-link:focus,
.submenu-link.active {
    background: var(--bg-secondary);
    color: var(--primary-color);
}

body.dark-mode .submenu-link:hover,
body.dark-mode .submenu-link:focus,
body.dark-mode .submenu-link.active {
    background: rgba(8, 145, 178, 0.15);
    color: #06b6d4;
}

.nav-link {
    color: var(--text-primary);
    font-weight: 500;
    font-size: 0.95rem;
    padding: 0.625rem 1.25rem;
    border-radius: var(--radius-full);
    transition: var(--transition-base);
    position: relative;
}

body.dark-mode .nav-link {
    color: #e5e5e5;
}

.nav-link::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: var(--radius-full);
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    opacity: 0;
    transition: var(--transition-base);
    z-index: -1;
}

.nav-link:hover::before,
.nav-link.active::before {
    opacity: 0.1;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
    transform: translateY(-2px);
}

body.dark-mode .nav-link:hover,
body.dark-mode .nav-link.active {
    color: #06b6d4;
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.hamburger {
    display: block;
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    position: relative;
    transition: var(--transition-base);
}

body.dark-mode .hamburger {
    background: #e5e5e5;
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition-base);
}

body.dark-mode .hamburger::before,
body.dark-mode .hamburger::after {
    background: #e5e5e5;
}

.hamburger::before { top: -8px; }
.hamburger::after { top: 8px; }

/* ===================================
   Hero Section
   =================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding-top: 80px;
    background: var(--bg-primary);
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: -50px;
    left: -50px;
    right: -50px;
    bottom: -50px;
    width: calc(100% + 100px);
    height: calc(100% + 100px);
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    opacity: 1;
}

.hero-background::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(236, 72, 153, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(6, 182, 212, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 40% 20%, rgba(245, 158, 11, 0.2) 0%, transparent 50%);
}

.hero-background::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        linear-gradient(30deg, rgba(255,255,255,0.05) 12%, transparent 12.5%, transparent 87%, rgba(255,255,255,0.05) 87.5%, rgba(255,255,255,0.05)),
        linear-gradient(150deg, rgba(255,255,255,0.05) 12%, transparent 12.5%, transparent 87%, rgba(255,255,255,0.05) 87.5%, rgba(255,255,255,0.05)),
        linear-gradient(30deg, rgba(255,255,255,0.05) 12%, transparent 12.5%, transparent 87%, rgba(255,255,255,0.05) 87.5%, rgba(255,255,255,0.05)),
        linear-gradient(150deg, rgba(255,255,255,0.05) 12%, transparent 12.5%, transparent 87%, rgba(255,255,255,0.05) 87.5%, rgba(255,255,255,0.05));
    background-size: 80px 140px;
    background-position: 0 0, 0 0, 40px 70px, 40px 70px;
}

.hero .container {
    position: relative;
    z-index: 1;
}

.hero-content-centered {
    display: flex;
    justify-content: center;
    align-items: center;
    max-width: 900px;
    margin: 0 auto;
}

.hero-text-centered {
    color: white;
    text-align: center;
    animation: fadeInUp 0.8s ease-out;
}

.hero-subtitle {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    opacity: 0.95;
    text-transform: uppercase;
    letter-spacing: 3px;
    display: inline-block;
    padding: 0.5rem 1.5rem;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-full);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.hero-title {
    font-size: 5rem;
    margin-bottom: var(--spacing-md);
    color: white;
    line-height: 1.1;
    font-weight: 800;
    letter-spacing: -0.02em;
}

.hero-tagline {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-sm);
    opacity: 0.95;
    font-weight: 600;
    line-height: 1.4;
}

.hero-organization {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xl);
    opacity: 0.9;
    font-weight: 300;
}

.hero-description {
    font-size: 1.25rem;
    line-height: 1.8;
    margin-bottom: var(--spacing-xl);
    opacity: 0.9;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    justify-content: center;
}

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

.scroll-indicator a {
    color: white;
    font-size: 2rem;
    opacity: 0.8;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 50%;
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: var(--transition-base);
}

.scroll-indicator a:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-5px);
}

/* Floating particles in hero */
.particle {
    position: absolute;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.15);
    animation: float 20s infinite;
}

.particle:nth-child(1) {
    width: 80px;
    height: 80px;
    left: 10%;
    top: 20%;
    animation-duration: 15s;
    animation-delay: 0s;
}

.particle:nth-child(2) {
    width: 60px;
    height: 60px;
    right: 15%;
    top: 30%;
    animation-duration: 18s;
    animation-delay: 2s;
}

.particle:nth-child(3) {
    width: 100px;
    height: 100px;
    left: 20%;
    bottom: 20%;
    animation-duration: 20s;
    animation-delay: 4s;
}

.particle:nth-child(4) {
    width: 50px;
    height: 50px;
    right: 25%;
    bottom: 30%;
    animation-duration: 16s;
    animation-delay: 1s;
}

.particle:nth-child(5) {
    width: 70px;
    height: 70px;
    left: 50%;
    top: 40%;
    animation-duration: 22s;
    animation-delay: 3s;
}

/* ===================================
   Buttons
   =================================== */
.btn {
    display: inline-block;
    padding: 1rem 2.5rem;
    border-radius: var(--radius-full);
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-base);
    border: 2px solid transparent;
    position: relative;
    overflow: hidden;
    font-size: 1rem;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: white;
    color: var(--primary-color);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.btn-primary:hover {
    background: white;
    transform: translateY(-3px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.3);
}

.btn-outline {
    background: transparent;
    color: white;
    border-color: rgba(255, 255, 255, 0.5);
    backdrop-filter: blur(10px);
}

.btn-outline:hover {
    background: white;
    color: var(--primary-color);
    border-color: white;
    transform: translateY(-3px);
}

/* ===================================
   About Section
   =================================== */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    align-items: start;
}

.contact-info {
    margin-top: var(--spacing-lg);
}

.contact-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

.contact-item i {
    color: var(--primary-color);
    width: 20px;
}

.about-highlights {
    display: grid;
    gap: var(--spacing-md);
}

.highlight-card {
    background: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-light);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.highlight-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(180deg, var(--primary-color) 0%, var(--accent-color) 100%);
    transition: var(--transition-base);
}

.highlight-card:hover {
    transform: translateY(-8px) translateX(5px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-light);
}

.highlight-card:hover::before {
    width: 100%;
    opacity: 0.05;
}

.highlight-icon {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.highlight-card h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.highlight-card p {
    color: var(--text-secondary);
    margin: 0;
}

/* ===================================
   Education Section
   =================================== */
.education-card {
    background: var(--bg-primary);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    margin-bottom: var(--spacing-xl);
    border: 1px solid var(--border-light);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.education-card::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.05) 0%, transparent 70%);
    pointer-events: none;
}

.education-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-light);
}

.education-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-lg);
    border-bottom: 2px solid var(--border-color);
}

.education-degree {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-xs);
    color: var(--primary-color);
}

.education-institution {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.education-location {
    color: var(--text-secondary);
}

.education-period {
    background: var(--bg-secondary);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    font-weight: 600;
    color: var(--text-primary);
}

.education-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.stat-item {
    background: var(--bg-secondary);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    text-align: center;
}

.specialization {
    margin-bottom: var(--spacing-lg);
}

.specialization p {
    margin-bottom: var(--spacing-xs);
}

.coursework h4 {
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.coursework ul {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-sm);
}

.coursework li {
    padding-left: var(--spacing-md);
    position: relative;
}

.coursework li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

/* ===================================
   Research Interests
   =================================== */
.interests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.interest-card {
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: all var(--transition-bounce);
    border: 1px solid var(--border-light);
    position: relative;
    overflow: hidden;
}

.interest-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    opacity: 0;
    transition: var(--transition-base);
}

.interest-card:hover {
    transform: translateY(-10px) scale(1.03);
    box-shadow: var(--shadow-2xl);
}

.interest-card:hover::before {
    opacity: 0.05;
}

.interest-card i {
    font-size: 3rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-md);
    position: relative;
    z-index: 1;
    transition: var(--transition-base);
}

.interest-card:hover i {
    transform: scale(1.1) rotate(5deg);
}

.interest-card h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
    position: relative;
    z-index: 1;
}

/* ===================================
   Timeline (Research)
   =================================== */
.timeline {
    position: relative;
    padding-left: 50px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(180deg, var(--primary-color) 0%, var(--secondary-color) 50%, var(--accent-color) 100%);
    border-radius: var(--radius-full);
    box-shadow: 0 0 20px rgba(99, 102, 241, 0.3);
}

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-xl);
}

.timeline-marker {
    position: absolute;
    left: -54px;
    top: 0;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    border: 4px solid white;
    box-shadow: 
        0 0 0 4px var(--primary-light),
        0 0 20px rgba(99, 102, 241, 0.5);
    z-index: 2;
}

.timeline-content {
    background: var(--bg-primary);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-light);
    transition: all var(--transition-base);
    position: relative;
}

.timeline-content::before {
    content: '';
    position: absolute;
    left: -12px;
    top: 8px;
    width: 0;
    height: 0;
    border-style: solid;
    border-width: 8px 12px 8px 0;
    border-color: transparent var(--bg-primary) transparent transparent;
}

.timeline-content:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-light);
}

.research-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: var(--spacing-md);
}

.research-title {
    font-size: 1.5rem;
    color: var(--text-primary);
    flex: 1;
}

.research-supervisor {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
}

.research-period {
    color: var(--text-secondary);
    font-style: italic;
    margin-bottom: var(--spacing-md);
}

.research-description {
    list-style: none;
}

.research-description li {
    padding-left: var(--spacing-lg);
    position: relative;
    margin-bottom: var(--spacing-sm);
}

.research-description li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* ===================================
   Badges
   =================================== */
.badge {
    display: inline-block;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    box-shadow: var(--shadow-sm);
    border: 1px solid transparent;
    transition: var(--transition-base);
}

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

.badge-ongoing {
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    color: #92400e;
    border-color: #fcd34d;
}

.badge-review-work {
    background: linear-gradient(135deg, #dbeafe 0%, #bfdbfe 100%);
    color: #1e40af;
    border-color: #93c5fd;
}

.badge-undergraduate-thesis {
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    color: #065f46;
    border-color: #6ee7b7;
}

.badge-status, .badge-in-preparation {
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    color: #92400e;
    border-color: #fcd34d;
}

.badge-accepted {
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    color: #065f46;
    border-color: #6ee7b7;
}

.badge-project {
    background: linear-gradient(135deg, #e0e7ff 0%, #c7d2fe 100%);
    color: #3730a3;
    border-color: #a5b4fc;
}

/* ===================================
   Publications
   =================================== */
.publications-subsection {
    margin-bottom: var(--spacing-2xl);
}

.publication-card {
    display: flex;
    gap: var(--spacing-lg);
    background: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    margin-bottom: var(--spacing-lg);
    transition: all var(--transition-base);
    border: 1px solid var(--border-light);
    position: relative;
    overflow: hidden;
}

.publication-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color) 0%, var(--accent-color) 100%);
    transform: scaleX(0);
    transform-origin: left;
    transition: var(--transition-base);
}

.publication-card:hover {
    box-shadow: var(--shadow-xl);
    transform: translateY(-5px);
    border-color: var(--primary-light);
}

.publication-card:hover::before {
    transform: scaleX(1);
}

.publication-icon {
    flex-shrink: 0;
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary-color) 100%);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-colored);
    transition: var(--transition-base);
}

.publication-card:hover .publication-icon {
    transform: scale(1.1) rotate(5deg);
    box-shadow: var(--shadow-glow);
}

.publication-icon i {
    font-size: 2rem;
    color: white;
}

.publication-authors {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
}

.publication-title {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.publication-venue {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

/* ===================================
   Experience & Projects
   =================================== */
.experience-card,
.project-card {
    background: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: var(--spacing-xl);
    border: 1px solid var(--border-light);
}

.experience-header,
.project-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--border-color);
}

.experience-position,
.project-title {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-xs);
}

.experience-organization,
.experience-institution,
.project-supervisors {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
}

.experience-period,
.project-period {
    background: var(--bg-secondary);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    font-weight: 600;
}

.experience-list,
.project-description {
    list-style: none;
}

.experience-list li,
.project-description li {
    padding-left: var(--spacing-lg);
    position: relative;
    margin-bottom: var(--spacing-sm);
}

.experience-list li::before,
.project-description li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--secondary-color);
    font-weight: bold;
}

/* ===================================
   Skills Section
   =================================== */
.skills-grid {
    display: grid;
    gap: var(--spacing-xl);
}

.skill-category {
    background: var(--bg-primary);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-light);
    transition: all var(--transition-base);
}

.skill-category:hover {
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-light);
}

.skill-category h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.skill-category h3 i {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.skill-subcategory {
    margin-bottom: var(--spacing-lg);
}

.skill-subcategory:last-child {
    margin-bottom: 0;
}

.skill-subcategory h4 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.skill-tag {
    background: var(--bg-secondary);
    padding: 0.625rem 1.25rem;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
    border: 1.5px solid var(--border-color);
    transition: all var(--transition-base);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.skill-tag::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    opacity: 0;
    transition: var(--transition-base);
}

.skill-tag:hover {
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-3px);
    box-shadow: var(--shadow-colored);
}

.skill-tag:hover::before {
    opacity: 1;
}

.skill-tag span {
    position: relative;
    z-index: 1;
}

.skill-tag-software {
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    border-color: #93c5fd;
    color: #1e40af;
}

.skill-tag-software:hover {
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
    border-color: #3b82f6;
    color: white;
}

.skill-tag-programming {
    background: linear-gradient(135deg, #f0fdf4 0%, #dcfce7 100%);
    border-color: #86efac;
    color: #166534;
}

.skill-tag-programming:hover {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    border-color: #10b981;
    color: white;
}

.language-list {
    display: grid;
    gap: var(--spacing-md);
}

.language-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md);
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
}

.language-name {
    font-weight: 600;
    color: var(--text-primary);
}

.language-level {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* ===================================
   Awards Section
   =================================== */
.awards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
}

.award-card {
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: all var(--transition-bounce);
    border: 1px solid var(--border-light);
    position: relative;
    overflow: hidden;
}

.award-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--accent-secondary) 0%, var(--accent-color) 100%);
    opacity: 0;
    transition: var(--transition-base);
}

.award-card:hover {
    transform: translateY(-10px) scale(1.03);
    box-shadow: var(--shadow-2xl);
}

.award-card:hover::before {
    opacity: 0.05;
}

.award-icon {
    font-size: 4rem;
    background: linear-gradient(135deg, var(--accent-secondary) 0%, var(--accent-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-md);
    position: relative;
    z-index: 1;
    transition: var(--transition-base);
}

.award-card:hover .award-icon {
    transform: scale(1.2) rotate(10deg);
}

.award-title {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.award-period {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.award-description {
    color: var(--text-secondary);
    margin: 0;
}

/* ===================================
   Activities Section
   =================================== */
.activities-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.activity-card {
    background: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    border: 1px solid var(--border-light);
    position: relative;
    overflow: hidden;
}

.activity-card::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.05) 0%, transparent 70%);
    transition: var(--transition-slow);
}

.activity-card:hover {
    box-shadow: var(--shadow-xl);
    transform: translateY(-5px);
    border-color: var(--primary-light);
}

.activity-card:hover::before {
    top: -25%;
    right: -25%;
    width: 300px;
    height: 300px;
}

.activity-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.activity-header i {
    font-size: 2.5rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: var(--transition-base);
}

.activity-card:hover .activity-header i {
    transform: scale(1.1) rotate(5deg);
}

.activity-header h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
}

.activity-org {
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
}

.activity-period {
    color: var(--text-light);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-md);
}

.activity-description {
    color: var(--text-secondary);
    margin: 0;
}

/* ===================================
   Contact Section
   =================================== */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
}

.contact-info-box {
    background: var(--bg-primary);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-light);
    transition: all var(--transition-base);
}

.contact-info-box:hover {
    box-shadow: var(--shadow-2xl);
    transform: translateY(-5px);
}

.contact-info-box h3 {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
}

.contact-details {
    margin-bottom: var(--spacing-xl);
}

.contact-detail {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.contact-detail i {
    font-size: 1.5rem;
    color: var(--primary-color);
    width: 30px;
    flex-shrink: 0;
}

.contact-detail h4 {
    font-size: 1rem;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

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

.social-links-contact h4 {
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.social-icons {
    display: flex;
    gap: var(--spacing-md);
}

.social-icons a {
    width: 55px;
    height: 55px;
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--primary-color);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
    border: 2px solid var(--border-light);
}

.social-icons a::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    opacity: 0;
    transition: var(--transition-base);
}

.social-icons a:hover {
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-5px);
    box-shadow: var(--shadow-colored);
}

.social-icons a:hover::before {
    opacity: 1;
}

.social-icons a i {
    position: relative;
    z-index: 1;
}

.contact-cta {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    padding: var(--spacing-3xl);
    border-radius: var(--radius-2xl);
    color: white;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-2xl);
}

.contact-cta::before {
    content: '';
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    opacity: 0.3;
}

.contact-cta > * {
    position: relative;
    z-index: 1;
}

.contact-cta h3 {
    font-size: 2.25rem;
    margin-bottom: var(--spacing-md);
    color: white;
    font-weight: 800;
}

.contact-cta p {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xl);
    opacity: 0.95;
    max-width: 500px;
}

.contact-cta .btn {
    background: white;
    color: var(--primary-color);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.contact-cta .btn:hover {
    background: rgba(255, 255, 255, 0.95);
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
}

/* ===================================
   Footer
   =================================== */
.site-footer {
    background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
    color: white;
    padding: var(--spacing-3xl) 0 var(--spacing-lg);
    position: relative;
    overflow: hidden;
}

.site-footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent 0%, var(--primary-color) 50%, transparent 100%);
}

.site-footer::after {
    content: '';
    position: absolute;
    top: -50%;
    right: -10%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.1) 0%, transparent 70%);
    pointer-events: none;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-xl);
}

.footer-section h3,
.footer-section h4 {
    color: white;
    margin-bottom: var(--spacing-md);
}

.footer-section p {
    color: rgba(255, 255, 255, 0.7);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    transition: var(--transition-base);
}

.footer-links a:hover {
    color: white;
}

.footer-section .social-links {
    display: flex;
    gap: var(--spacing-md);
}

.footer-section .social-links a {
    width: 45px;
    height: 45px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    transition: all var(--transition-base);
    border: 1px solid rgba(255, 255, 255, 0.1);
    position: relative;
    overflow: hidden;
}

.footer-section .social-links a::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    opacity: 0;
    transition: var(--transition-base);
}

.footer-section .social-links a:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.4);
}

.footer-section .social-links a:hover::before {
    opacity: 1;
}

.footer-section .social-links a i {
    position: relative;
    z-index: 1;
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.5);
    margin: 0;
}

/* ===================================
   Scroll to Top Button
   =================================== */
.scroll-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 55px;
    height: 55px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    box-shadow: var(--shadow-xl), 0 0 30px rgba(99, 102, 241, 0.4);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    z-index: 999;
}

.scroll-to-top::before {
    content: '';
    position: absolute;
    inset: -3px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    opacity: 0;
    transition: var(--transition-base);
    z-index: -1;
}

.scroll-to-top.visible {
    opacity: 1;
    visibility: visible;
    animation: float 3s ease-in-out infinite;
}

.scroll-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-2xl), 0 0 40px rgba(99, 102, 241, 0.6);
}

.scroll-to-top:hover::before {
    opacity: 0.3;
    inset: -8px;
}

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

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

@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 rotate {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

@keyframes shimmer {
    0% {
        background-position: -1000px 0;
    }
    100% {
        background-position: 1000px 0;
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-20px);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

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

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 1024px) {
    h1 { font-size: 3rem; }
    h2 { font-size: 2rem; }
    
    .hero-title {
        font-size: 3.5rem;
    }
    
    .hero-content-centered {
        padding: 0 var(--spacing-lg);
    }
    
    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: var(--transition-base);
        box-shadow: var(--shadow-lg);
        padding: var(--spacing-lg) 0;
    }
    
    body.dark-mode .nav-menu {
        background-color: var(--bg-secondary);
    }
    
    .nav-item {
        width: 100%;
    }

    .submenu {
        position: static;
        background: transparent;
        box-shadow: none;
        border: none;
        padding: 0;
        margin-top: 0.25rem;
        opacity: 1;
        pointer-events: auto;
        transform: none;
        display: none;
        gap: 0;
    }

    .has-submenu.open .submenu {
        display: block;
    }

    .submenu-link {
        padding: 0.75rem 1.5rem;
        border-radius: var(--radius-full);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-toggle {
        display: block;
    }
    
    h1 { font-size: 2.5rem; }
    h2 { font-size: 1.75rem; }
    
    .hero {
        padding-top: 100px;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-tagline {
        font-size: 1.25rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    .section {
        padding: var(--spacing-xl) 0;
    }
    
    .education-header,
    .experience-header,
    .project-header {
        flex-direction: column;
    }
    
    .education-stats {
        grid-template-columns: 1fr;
    }
    
    .coursework ul {
        grid-template-columns: 1fr;
    }
    
    .interests-grid,
    .awards-grid,
    .activities-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    html {
        font-size: 14px;
    }
    
    .container {
        padding: 0 var(--spacing-md);
    }
    
    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }
    
    .hero-buttons .btn {
        width: 100%;
    }
    
    .hero-title {
        font-size: 2rem;
    }
}