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

:root {
    --bg-color: #050505;
    --surface-color: #121212;
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --accent-color: #00f2ff;
    --accent-glow: rgba(0, 242, 255, 0.4);
    --border-color: #2a2a2a;
}

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

body {
    font-family: 'Outfit', sans-serif;
    background-color: var(--bg-color);
    background-image: radial-gradient(circle at 50% 0%, #1a1a1a 0%, var(--bg-color) 70%);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

html {
    scroll-behavior: smooth;
}

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

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

::-webkit-scrollbar-thumb {
    background: #333;
    border-radius: 5px;
}

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

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.3s ease;
}

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

ul {
    list-style: none;
}

section {
    padding: 80px 20px;
    max-width: 1200px;
    margin: 0 auto;
}

h1,
h2,
h3 {
    line-height: 1.2;
}

h2 {
    font-size: 2.5rem;
    margin-bottom: 40px;
    position: relative;
    display: inline-block;
}

h2::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: var(--accent-color);
    margin-top: 10px;
    border-radius: 2px;
}

/* Header */
header {
    position: fixed;
    top: 0;
    width: 100%;
    padding: 20px 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(5, 5, 5, 0.8);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

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

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

/* Hamburger Menu */
.hamburger {
    display: none;
    cursor: pointer;
    flex-direction: column;
    gap: 5px;
    z-index: 1001;
}

.hamburger .line {
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    border-radius: 2px;
    transition: all 0.3s ease;
}

/* Hamburger Animation */
.hamburger.active .line:nth-child(1) {
    transform: rotate(45deg) translate(5px, 6px);
    background-color: var(--accent-color);
}

.hamburger.active .line:nth-child(2) {
    opacity: 0;
}

.hamburger.active .line:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -6px);
    background-color: var(--accent-color);
}

.nav-links ul {
    display: flex;
    gap: 30px;
}

.nav-links a {
    font-size: 0.9rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 1px;
    opacity: 0.8;
}

.nav-links a:hover {
    opacity: 1;
    color: var(--accent-color);
}

/* Hero Section */
.hero {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
    padding-top: 80px;
    /* Offset for header */
}

.hero-content h1 {
    font-size: 4rem;
    margin-bottom: 20px;
    background: linear-gradient(90deg, #fff, var(--text-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-content p {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 40px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.highlight {
    color: var(--accent-color);
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    border: 1px solid var(--accent-color);
    color: var(--accent-color);
    border-radius: 30px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: all 0.3s ease;
}

.btn:hover {
    background: var(--accent-color);
    color: var(--bg-color);
    box-shadow: 0 0 20px var(--accent-glow);
}

/* About Section */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text p {
    margin-bottom: 20px;
    color: var(--text-secondary);
}

.skills-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 20px;
}

.tag {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.9rem;
    color: var(--accent-color);
}

/* Research/Publications */
.publication-card {
    background: var(--surface-color);
    padding: 30px;
    border-radius: 12px;
    margin-bottom: 20px;
    border: 1px solid var(--border-color);
    transition: transform 0.3s ease, border-color 0.3s ease;
}

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

.publication-card h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
    color: var(--text-primary);
}

.publication-meta {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 15px;
}

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

.timeline::after {
    content: '';
    position: absolute;
    width: 2px;
    background-color: var(--border-color);
    top: 0;
    bottom: 0;
    left: 20px;
    margin-left: -1px;
}

.timeline-item {
    padding: 10px 40px;
    position: relative;
    background-color: inherit;
    width: 100%;
    margin-bottom: 30px;
}

.timeline-item::after {
    content: '';
    position: absolute;
    width: 16px;
    height: 16px;
    right: auto;
    left: 12px;
    /* Adjust for line position */
    background-color: var(--surface-color);
    border: 2px solid var(--accent-color);
    top: 15px;
    border-radius: 50%;
    z-index: 1;
}

.timeline-content {
    padding: 20px 30px;
    background-color: var(--surface-color);
    position: relative;
    border-radius: 6px;
    border: 1px solid var(--border-color);
}

.timeline-content h3 {
    color: var(--accent-color);
    font-size: 1.2rem;
    margin-bottom: 5px;
}

.timeline-content h4 {
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.timeline-date {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 10px;
    display: inline-block;
    background: rgba(255, 255, 255, 0.05);
    padding: 4px 10px;
    border-radius: 4px;
}

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

/* Education Section */
.education-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.education-card {
    background: var(--surface-color);
    padding: 30px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    text-align: center;
}

.education-card h3 {
    color: var(--accent-color);
    margin-bottom: 10px;
}

.education-score {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: 15px 0;
}

/* Contact/Footer */
footer {
    background: var(--surface-color);
    padding: 60px 20px;
    text-align: center;
    border-top: 1px solid var(--border-color);
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-bottom: 30px;
}

.social-links a {
    font-size: 1.5rem;
    color: var(--text-secondary);
}

.social-links a:hover {
    color: var(--accent-color);
    transform: scale(1.1);
}

.copyright {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Animations */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Back to Top Button */
#back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background-color: var(--surface-color);
    border: 1px solid var(--accent-color);
    color: var(--accent-color);
    width: 45px;
    height: 45px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 999;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

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

#back-to-top:hover {
    background-color: var(--accent-color);
    color: var(--bg-color);
    transform: translateY(-5px);
}

/* Responsive */
@media (max-width: 768px) {
    .hero-content h1 {
        font-size: 2.5rem;
    }

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

    .hamburger {
        display: flex;
    }

    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        height: 100vh;
        width: 70%;
        background: rgba(5, 5, 5, 0.95);
        backdrop-filter: blur(10px);
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        transition: right 0.4s ease;
        border-left: 1px solid var(--border-color);
    }

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

    .nav-links ul {
        flex-direction: column;
        text-align: center;
        gap: 40px;
    }

    .nav-links a {
        font-size: 1.2rem;
    }
}