:root {
    --bg-color: #030712;
    --bg-secondary: #0f172a;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-primary: #3b82f6;
    --accent-secondary: #8b5cf6;
    --gradient-main: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
    --gradient-hover: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
    --card-bg: rgba(30, 41, 59, 0.5);
    --border-color: rgba(148, 163, 184, 0.1);
    --font-heading: 'Space Grotesk', sans-serif;
    --font-body: 'Outfit', sans-serif;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-color);
}

::-webkit-scrollbar-thumb {
    background: var(--card-bg);
    border-radius: 5px;
}

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

/* Cursor Glow Effect */
.cursor-glow {
    position: fixed;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle at center, rgba(59, 130, 246, 0.15) 0%, rgba(3, 7, 18, 0) 70%);
    border-radius: 50%;
    pointer-events: none;
    transform: translate(-50%, -50%);
    z-index: 0;
    transition: left 0.1s ease, top 0.1s ease;
}

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

.highlight {
    background: var(--gradient-main);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    padding: 1.5rem 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(3, 7, 18, 0.8);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
    transition: padding 0.3s ease;
}

.navbar.scrolled {
    padding: 1rem 5%;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    font-family: var(--font-heading);
    letter-spacing: 2px;
}

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

.nav-links a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--text-primary);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-main);
    transition: var(--transition);
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

/* Buttons */
.btn-primary,
.btn-secondary {
    display: inline-block;
    padding: 0.8rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-family: var(--font-heading);
    transition: var(--transition);
}

.btn-primary {
    background: var(--gradient-main);
    color: white;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(59, 130, 246, 0.5);
    background: var(--gradient-hover);
}

.btn-secondary {
    background: transparent;
    border: 1px solid var(--accent-primary);
    color: var(--text-primary);
    margin-right: 1rem;
}

.btn-secondary:hover {
    background: rgba(59, 130, 246, 0.1);
    transform: translateY(-2px);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 0 5%;
    position: relative;
    overflow: hidden;
}

.hero-content {
    flex: 1;
    z-index: 2;
    max-width: 800px;
}

.hero h2 {
    font-size: 1.5rem;
    color: var(--accent-primary);
    margin-bottom: 1rem;
}

.hero h1 {
    font-size: 4.5rem;
    margin-bottom: 1.5rem;
}

.hero .subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    max-width: 600px;
}

/* Background Effects */
.grid-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image:
        linear-gradient(rgba(15, 23, 42, 0.9) 1px, transparent 1px),
        linear-gradient(90deg, rgba(15, 23, 42, 0.9) 1px, transparent 1px);
    background-size: 50px 50px;
    opacity: 0.2;
    z-index: 1;
}

.glow-orb {
    position: absolute;
    top: 50%;
    right: -10%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.2) 0%, rgba(139, 92, 246, 0.2) 50%, transparent 70%);
    filter: blur(80px);
    border-radius: 50%;
    z-index: 1;
    animation: float 10s infinite ease-in-out;
}

@keyframes float {

    0%,
    100% {
        transform: translate(0, 0);
    }

    50% {
        transform: translate(-20px, -20px);
    }
}

/* Sections */
.section {
    padding: 6rem 5%;
    position: relative;
    z-index: 2;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

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

.section-header h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.line {
    width: 60px;
    height: 4px;
    background: var(--gradient-main);
    border-radius: 2px;
}

.dark-bg {
    background: var(--bg-secondary);
}

/* About Grid */
.about-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-text p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.skills-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
}

.skills-list li {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.skills-list li i {
    color: var(--accent-secondary);
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
}

.stat-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 20px;
    border: 1px solid var(--border-color);
    text-align: center;
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent-primary);
}

.stat-card h3 {
    font-size: 2.5rem;
    color: var(--accent-primary);
    margin-bottom: 0.5rem;
}

/* Timeline */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border-color);
}

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

.timeline-dot {
    position: absolute;
    left: -4px;
    top: 0;
    width: 10px;
    height: 10px;
    background: var(--accent-primary);
    border-radius: 50%;
    box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.2);
}

.timeline-date {
    color: var(--accent-secondary);
    font-weight: 600;
    margin-bottom: 0.5rem;
    font-family: var(--font-heading);
}

.timeline-content {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 15px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.timeline-content:hover {
    border-color: var(--accent-primary);
    background: rgba(30, 41, 59, 0.7);
}

.timeline-content h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
}

.timeline-content h4 {
    color: var(--text-secondary);
    font-weight: 500;
    margin-bottom: 1rem;
}

.timeline-content ul {
    list-style: inside;
    color: var(--text-secondary);
}

.timeline-content li {
    margin-bottom: 0.5rem;
}

/* Research & Education */
.research-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.edu-item {
    margin-bottom: 2rem;
    padding-left: 1.5rem;
    border-left: 2px solid var(--accent-secondary);
}

.badge {
    display: inline-block;
    padding: 0.2rem 0.8rem;
    background: rgba(139, 92, 246, 0.1);
    color: var(--accent-secondary);
    border-radius: 20px;
    font-size: 0.8rem;
    margin-top: 0.5rem;
}

.link-buttons {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin-top: 2rem;
}

.resource-card {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 15px;
    border: 1px solid var(--border-color);
    text-decoration: none;
    color: var(--text-primary);
    transition: var(--transition);
}

.resource-card:hover {
    transform: translateX(10px);
    border-color: var(--accent-primary);
    background: rgba(30, 41, 59, 0.8);
}

.resource-card i {
    font-size: 1.5rem;
    color: var(--accent-primary);
}

.resource-card .arrow {
    margin-left: auto;
    font-size: 1rem;
    opacity: 0;
    transform: translateX(-10px);
    transition: var(--transition);
}

.resource-card:hover .arrow {
    opacity: 1;
    transform: translateX(0);
}

/* Contact */
.text-center {
    text-align: center;
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-top: 3rem;
    flex-wrap: wrap;
}

.contact-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    text-decoration: none;
    color: var(--text-secondary);
    padding: 2rem;
    background: var(--card-bg);
    border-radius: 15px;
    width: 200px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.contact-item:hover {
    background: var(--bg-color);
    color: var(--accent-primary);
    transform: translateY(-5px);
    border-color: var(--accent-primary);
}

.contact-item i {
    font-size: 2rem;
}

.footer {
    margin-top: 6rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Mobile Responsiveness */
.hamburger {
    display: none;
    cursor: pointer;
}

@media (max-width: 768px) {
    .navbar {
        padding: 1rem 5%;
    }

    .hamburger {
        display: block;
    }

    .hamburger span {
        display: block;
        width: 25px;
        height: 3px;
        background: var(--text-primary);
        margin: 5px 0;
        transition: var(--transition);
    }

    .nav-links {
        position: fixed;
        top: 70px;
        right: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: var(--bg-color);
        flex-direction: column;
        justify-content: center;
        transition: 0.5s ease;
    }

    .nav-links.active {
        right: 0;
    }

    .hero h1 {
        font-size: 3rem;
    }

    .about-grid,
    .research-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .timeline {
        padding-left: 1rem;
    }

    .hero {
        padding-top: 80px;
    }
}

/* Refinements: Projects & Photo */
.navbar {
    justify-content: center;
}

.about-grid {
    grid-template-columns: 300px 1fr !important;
    gap: 4rem;
    align-items: start;
}

.about-photo img {
    width: 100%;
    border-radius: 20px;
    border: 2px solid var(--accent-primary);
    box-shadow: 0 0 20px rgba(59, 130, 246, 0.3);
    transition: var(--transition);
}

.about-photo img:hover {
    transform: scale(1.02);
    box-shadow: 0 0 30px rgba(59, 130, 246, 0.5);
}

.about-content-wrapper {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

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

.project-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    position: relative;
    overflow: hidden;
    transition: var(--transition);
    height: 100%;
    display: flex;
    flex-direction: column;
}

.project-img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: var(--transition);
}

.project-card:hover .project-img {
    transform: scale(1.1);
}

.project-content {
    padding: 1.5rem;
    position: relative;
    z-index: 2;
    background: var(--card-bg);
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.project-card h3 {
    font-size: 1.3rem;
    color: var(--accent-primary);
    margin-bottom: 0.8rem;
}

.project-card p {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.project-card::before {
    display: none;
    /* Remove gradient overlay in favor of clean image+text card */
}

.project-card:hover {
    transform: translateY(-10px);
    border-color: var(--accent-primary);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.project-card.placeholder {
    border-style: dashed;
    justify-content: center;
    align-items: center;
    text-align: center;
}

@media (max-width: 768px) {
    .about-grid {
        grid-template-columns: 1fr !important;
    }

    .about-photo {
        max-width: 300px;
        margin: 0 auto;
    }
}

/* Animations */
.animate-up {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s forwards;
}

.delay-1 {
    animation-delay: 0.2s;
}

.delay-2 {
    animation-delay: 0.4s;
}

.delay-3 {
    animation-delay: 0.6s;
}

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