:root {
    --primary-color: #0d253f;
    /* Deep Navy */
    --secondary-color: #1e88e5;
    /* Professional Blue */
    --accent-color: #ff9800;
    /* Subtle warm accent */
    --text-color: #333333;
    --text-light: #666666;
    --bg-color: #ffffff;
    --bg-light: #f4f6f8;
    --white: #ffffff;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
    --font-main: 'Inter', sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

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

#bg-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

/* Typography */
h1,
h2,
h3,
h4 {
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

h1 {
    font-size: 3.5rem;
}

h2 {
    font-size: 2.5rem;
}

h3 {
    font-size: 1.5rem;
}

p {
    margin-bottom: 1rem;
    color: var(--text-text);
}

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

ul {
    list-style: none;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section-title {
    text-align: center;
    margin-bottom: 3rem;
    position: relative;
    display: inline-block;
    left: 50%;
    transform: translateX(-50%);
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: var(--secondary-color);
    margin: 0.5rem auto 0;
    border-radius: 2px;
}

.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

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

.btn.primary:hover {
    background-color: transparent;
    color: var(--secondary-color);
}

.btn.secondary {
    background-color: transparent;
    color: var(--secondary-color);
    border: 2px solid var(--secondary-color);
    margin-left: 1rem;
}

.btn.secondary:hover {
    background-color: var(--secondary-color);
    color: var(--white);
}

/* Header */
header {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    height: 80px;
    display: flex;
    align-items: center;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    letter-spacing: -0.5px;
}

.nav-links {
    display: flex;
}

.nav-links li {
    margin-left: 2rem;
}

.nav-links a {
    font-weight: 500;
    font-size: 0.95rem;
    color: var(--text-color);
}

.nav-links a:hover {
    color: var(--secondary-color);
}

.burger {
    display: none;
    cursor: pointer;
}

.burger div {
    width: 25px;
    height: 3px;
    background-color: var(--primary-color);
    margin: 5px;
    transition: var(--transition);
}

/* Hero Section */
#hero {
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    background: var(--bg-light);
    /* Could add a subtle pattern here */
    position: relative;
    padding-top: 80px;
}

.greeting {
    font-size: 1.2rem;
    color: var(--secondary-color);
    font-weight: 500;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.tagline {
    font-size: 1.5rem;
    color: var(--text-light);
    margin-bottom: 2.5rem;
}

.profile-img {
    width: 180px;
    height: 180px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 1.5rem;
    border: 5px solid var(--white);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    animation: fadeIn 1.5s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

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

.scroll-down {
    position: absolute;
    bottom: 30px;
    animation: bounce 2s infinite;
    color: var(--text-light);
    font-size: 1.5rem;
}

@keyframes bounce {

    0%,
    20%,
    50%,
    80%,
    100% {
        transform: translateY(0);
    }

    40% {
        transform: translateY(-10px);
    }

    60% {
        transform: translateY(-5px);
    }
}

/* Sections General */
section {
    padding: 6rem 0;
}

section:nth-child(even) {
    background-color: var(--bg-light);
}

/* About */
.about-content {
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
}

.about-text {
    max-width: 800px;
}

.about-text p {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
    color: var(--text-light);
}

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

.timeline::after {
    content: '';
    position: absolute;
    width: 4px;
    background-color: var(--secondary-color);
    top: 0;
    bottom: 0;
    left: 50%;
    margin-left: -2px;
}

.timeline-item {
    padding: 10px 40px;
    position: relative;
    width: 50%;
}

.timeline-item::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    right: -10px;
    background-color: var(--white);
    border: 4px solid var(--secondary-color);
    top: 15px;
    border-radius: 50%;
    z-index: 1;
}

.timeline-item:nth-child(even) {
    left: 50%;
}

.timeline-item:nth-child(odd) {
    left: 0;
}

.timeline-item:nth-child(even)::after {
    left: -10px;
}

.timeline-content {
    background: var(--white);
    border-radius: 8px;
    /* Smooth corners */
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

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

.company {
    font-weight: 600;
    color: var(--secondary-color);
    display: block;
    margin-bottom: 0.5rem;
}

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

/* Education (Cards) */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    max-width: 1100px;
    margin: 0 auto;
}

.cards-grid .card:first-child {
    grid-column: 1 / -1;
}

.card {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: var(--transition);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
}

.card h3 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
}

.institution {
    display: block;
    color: var(--secondary-color);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.year {
    font-size: 0.9rem;
    color: var(--text-light);
}

/* Research */
.section-subtitle {
    text-align: center;
    color: var(--text-light);
    margin-top: -2rem;
    margin-bottom: 3rem;
}

.interests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.interest-item {
    text-align: center;
    padding: 2rem;
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.interest-item i {
    font-size: 2.5rem;
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.research-cta {
    text-align: center;
}

.research-cta p {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

/* Contact */
.contact-methods {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.contact-link {
    display: flex;
    align-items: center;
    gap: 1rem;
    font-size: 1.2rem;
    color: var(--text-color);
    padding: 1rem 2rem;
    background: var(--white);
    border-radius: 50px;
    box-shadow: var(--shadow);
}

.contact-link:hover {
    color: var(--secondary-color);
    transform: translateY(-3px);
}

/* Skills Section */
#skills {
    background: var(--bg-light);
    padding: 4rem 0;
}

.skills-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
    margin-top: 3rem;
}

.skill-category {
    background: var(--white);
    padding: 2.5rem;
    border-radius: 12px;
    border: 1px solid #e8f0f7;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    transition: var(--transition);
    min-height: 350px;
    display: flex;
    flex-direction: column;
}

.skill-category:hover {
    box-shadow: 0 8px 24px rgba(30, 136, 229, 0.2);
    transform: translateY(-6px);
    border-color: var(--secondary-color);
}

.skill-category h3 {
    color: var(--secondary-color);
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.skill-category i {
    font-size: 1.3rem;
}

.skill-list {
    list-style: none;
    padding: 0;
}

.skill-list li {
    color: var(--text-color);
    font-size: 0.95rem;
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    line-height: 1.5;
}

.skill-list li:before {
    content: "▸";
    color: var(--secondary-color);
    font-weight: bold;
    position: absolute;
    left: 0;
}

/* Footer */
footer {
    background: var(--primary-color);
    color: var(--white);
    padding: 2rem 0;
    text-align: center;
}

/* Publications Section */
#publications {
    background: linear-gradient(135deg, #f8f9fa 0%, #f0f3f7 100%);
    padding: 4rem 0;
}

.publications-list {
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
    margin-top: 3rem;
}

.publication-item {
    background: var(--white);
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    padding: 2.5rem;
    transition: var(--transition);
    box-shadow: 0 4px 12px rgba(30, 136, 229, 0.08);
}

.publication-item:hover {
    box-shadow: var(--shadow);
    border: 1px solid var(--secondary-color);
    border-left: 4px solid var(--secondary-color);
    transform: translateY(-2px);
}

.publication-item h3 {
    color: var(--primary-color);
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.authors {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 0.75rem;
    font-style: italic;
}

.publication-meta {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1rem;
    font-size: 0.9rem;
    flex-wrap: wrap;
}

.publication-meta .year {
    background: var(--secondary-color);
    color: var(--white);
    padding: 0.4rem 0.9rem;
    border-radius: 4px;
    font-weight: 700;
    font-size: 0.85rem;
}

.publication-meta .venue {
    color: var(--text-light);
    font-weight: 500;
}

.publication-item .description {
    color: var(--text-color);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.publication-links {
    display: flex;
    gap: 1rem;
}

.btn-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--secondary-color);
    color: var(--white);
    text-decoration: none;
    border-radius: 4px;
    font-size: 0.9rem;
    transition: var(--transition);
    border: none;
    cursor: pointer;
}

.btn-link:hover {
    background: var(--primary-color);
    transform: translateY(-2px);
}

.btn-link i {
    font-size: 0.85rem;
}

/* Responsive */
@media screen and (max-width: 768px) {
    .nav-links {
        position: absolute;
        right: 0px;
        height: 92vh;
        top: 80px;
        background-color: var(--white);
        display: flex;
        flex-direction: column;
        align-items: center;
        width: 50%;
        transform: translateX(100%);
        transition: transform 0.5s ease-in;
        box-shadow: -2px 0 10px rgba(0, 0, 0, 0.1);
    }

    .nav-links li {
        opacity: 0;
        margin: 2rem 0;
    }

    .burger {
        display: block;
    }

    .nav-active {
        transform: translateX(0%);
    }

    @keyframes navLinkFade {
        from {
            opacity: 0;
            transform: translateX(50px);
        }

        to {
            opacity: 1;
            transform: translateX(0);
        }
    }

    .timeline::after {
        left: 31px;
    }

    .timeline-item {
        width: 100%;
        padding-left: 70px;
        padding-right: 25px;
    }

    .timeline-item::after {
        left: 21px;
        /* Adjust based on new line position */
    }

    .timeline-item:nth-child(even) {
        left: 0%;
    }

    h1 {
        font-size: 2.5rem;
    }



    h2 {
        font-size: 2rem;
    }

    .hero-content .cta-buttons {
        display: flex;
        flex-direction: column;
        gap: 1rem;
    }

    .btn.secondary {
        margin-left: 0;
    }

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

    .skill-category {
        padding: 1.5rem;
    }

    .skill-category h3 {
        font-size: 1rem;
    }

    .publication-item {
        padding: 1.5rem;
    }

    .publication-item h3 {
        font-size: 1.1rem;
    }

    .publication-meta {
        flex-direction: column;
        gap: 0.5rem;
    }

    .publication-links {
        flex-direction: column;
    }

    .btn-link {
        justify-content: center;
    }
}

.toggle .line1 {
    transform: rotate(-45deg) translate(-5px, 6px);
}

.toggle .line2 {
    opacity: 0;
}

.toggle .line3 {
    transform: rotate(45deg) translate(-5px, -6px);
}