:root {
    --primary-color: #2c3e50;
    --accent-color: #2980b9;
    --text-color: #333;
    --bg-color: #fff;
    --light-bg: #f8f9fa;
    --border-color: #e1e4e8;
    --font-heading: 'Lora', serif;
    --font-body: 'Poppins', sans-serif;
    --max-width: 900px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    font-size: 16px;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    color: var(--primary-color);
    margin-bottom: 0.5em;
    font-weight: 700;
}

a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: #1a5276;
    text-decoration: underline;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
header {
    padding: 60px 0 40px;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.subtitle {
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 20px;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 30px;
}

.social-links a {
    color: #555;
    font-size: 1.5rem;
}

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

/* Nav */
nav {
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
    padding: 15px 0;
    margin-bottom: 40px;
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(5px);
    z-index: 100;
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 30px;
    flex-wrap: wrap;
}

nav a {
    color: var(--primary-color);
    font-weight: 500;
    text-transform: uppercase;
    font-size: 0.9rem;
    letter-spacing: 1px;
}

nav a:hover {
    color: var(--accent-color);
    text-decoration: none;
}

nav a.active {
    color: var(--accent-color);
    border-bottom: 2px solid var(--accent-color);
    padding-bottom: 2px;
}

/* Sections */
section {
    padding: 40px 0;
    margin-bottom: 20px;
    scroll-margin-top: 90px;
}

.section-title {
    font-size: 1.8rem;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 10px;
    margin-bottom: 30px;
    margin-top: 20px;
}

/* About */
.about-content {
    display: flex;
    gap: 40px;
    align-items: flex-start;
}

.profile-pic {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    flex-shrink: 0;
    border: 3px solid var(--border-color);
}

.about-text {
    flex: 1;
}

/* Projects Grid */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 30px;
}

.project-card {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    transition: transform 0.2s, box-shadow 0.2s;
    background: #fff;
    display: flex;
    flex-direction: column;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.project-img {
    width: 100%;
    height: 180px;
    object-fit: cover;
    border-bottom: 1px solid var(--border-color);
}

.project-info {
    padding: 20px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.project-title {
    font-size: 1.2rem;
    margin-bottom: 10px;
}

.project-tags {
    font-size: 0.8rem;
    color: #666;
    margin-bottom: 10px;
    font-style: italic;
}

.project-desc {
    font-size: 0.9rem;
    color: #444;
    margin-bottom: 15px;
    flex: 1;
}

.project-links a {
    font-size: 0.9rem;
    margin-right: 15px;
    font-weight: 600;
}

/* Gallery */
.gallery-intro {
    color: #555;
    margin-bottom: 15px;
}

.carousel {
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 10px;
    background: var(--light-bg);
    position: relative;
    overflow: hidden;
}

.carousel-track {
    display: flex;
    gap: 12px;
    width: max-content;
    animation: carousel-scroll 40s linear infinite;
}

.carousel-track img {
    width: 200px;
    height: 130px;
    object-fit: cover;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    scroll-snap-align: center;
    flex: 0 0 auto;
}

.carousel:hover .carousel-track {
    animation-play-state: paused;
}

@keyframes carousel-scroll {
    0% {
        transform: translateX(0);
    }
    100% {
        transform: translateX(-50%);
    }
}

.gallery-cta {
    margin-top: 15px;
    text-align: center;
}

.gallery-link {
    display: inline-block;
    padding: 10px 16px;
    border-radius: 6px;
    background: var(--accent-color);
    color: #fff;
    font-weight: 600;
}

.gallery-link:hover {
    color: #fff;
    text-decoration: none;
    background: #1a5276;
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 20px;
}

.gallery-item {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    background: #fff;
}

.gallery-item img {
    width: 100%;
    height: 160px;
    object-fit: cover;
    display: block;
}

/* Lightbox */
.lightbox-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.85);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 20px;
}

.lightbox-overlay.is-open {
    display: flex;
}

.lightbox-content {
    position: relative;
    max-width: 92vw;
    max-height: 86vh;
}

.lightbox-image {
    max-width: 92vw;
    max-height: 86vh;
    width: auto;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}

.lightbox-close,
.lightbox-prev,
.lightbox-next {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(0, 0, 0, 0.6);
    color: #fff;
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
}

.lightbox-close {
    top: -12px;
    right: -12px;
    transform: none;
}

.lightbox-prev {
    left: -50px;
}

.lightbox-next {
    right: -50px;
}

.lightbox-caption {
    margin-top: 10px;
    text-align: center;
    color: #eee;
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .lightbox-prev,
    .lightbox-next {
        display: none;
    }
}

@media (prefers-reduced-motion: reduce) {
    .carousel-track {
        animation: none;
    }
}

/* Publications */
.pub-item {
    margin-bottom: 25px;
}

.pub-year {
    font-weight: 700;
    color: #666;
    font-size: 0.9rem;
    margin-bottom: 5px;
}

.pub-title {
    font-weight: 600;
    font-size: 1.1rem;
    display: inline;
}

.pub-authors {
    color: #555;
}

.pub-venue {
    font-style: italic;
    color: #444;
}

/* Experience & Resume */
.exp-item {
    margin-bottom: 30px;
    padding-left: 20px;
    border-left: 3px solid var(--border-color);
}

.exp-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 5px;
    flex-wrap: wrap;
}

.exp-role {
    font-weight: 700;
    font-size: 1.1rem;
}

.exp-date {
    color: #666;
    font-size: 0.9rem;
}

.exp-company {
    font-weight: 600;
    color: var(--accent-color);
    margin-bottom: 5px;
    display: block;
}

.exp-details {
    font-size: 0.95rem;
    color: #444;
}
.exp-details ul {
    padding-left: 20px;
    margin-top: 5px;
}

/* Skills */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
}

.skill-category h4 {
    font-size: 1.1rem;
    margin-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 5px;
}

.skill-list {
    font-size: 0.9rem;
    color: #555;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .about-content {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    
    nav {
        position: static;
        padding: 8px 0;
        margin-bottom: 20px;
    }

    nav ul {
        flex-direction: row;
        flex-wrap: nowrap;
        gap: 16px;
        justify-content: flex-start;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
        padding-bottom: 6px;
    }

    nav a {
        font-size: 0.75rem;
        white-space: nowrap;
    }

    section {
        scroll-margin-top: 20px;
    }
    
    .exp-header {
        flex-direction: column;
    }
}