/* Modern Academic Portfolio CSS */

/* CSS Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #fff;
    font-size: 16px;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Typography */
h1, h2, h3, h4 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 {
    font-size: 3.5rem;
    font-weight: 700;
}

h2 {
    font-size: 2.5rem;
    color: #2c3e50;
}

h3 {
    font-size: 1.5rem;
    color: #34495e;
}

p {
    margin-bottom: 1.2rem;
    color: #555;
    line-height: 1.7;
}

a {
    color: #3498db;
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: #2980b9;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid #eee;
    z-index: 1000;
    padding: 1rem 0;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: #2c3e50;
    text-decoration: none;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    color: #555;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: #3498db;
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 0;
    background-color: #3498db;
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: #333;
    margin: 3px 0;
    transition: 0.3s;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 0.9rem;
}

.btn-primary {
    background: #3498db;
    color: white;
}

.btn-primary:hover {
    background: #2980b9;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(52, 152, 219, 0.3);
}

.btn-outline {
    background: transparent;
    color: #3498db;
    border: 2px solid #3498db;
}

.btn-outline:hover {
    background: #3498db;
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(52, 152, 219, 0.3);
}

/* Sections */
section {
    padding: 1rem 0;
}

.section-title {
    text-align: center;
    margin-bottom: 3rem;
    position: relative;
}

.section-title::after {
    content: '';
    width: 80px;
    height: 4px;
    background: linear-gradient(135deg, #3498db, #2ecc71);
    display: block;
    margin: 1rem auto;
    border-radius: 2px;
}

.section-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

/* Hero Section */
.hero {
    min-height: 60vh;
    display: flex;
    align-items: center;
    padding: 2rem 0;
    background: linear-gradient(135deg, #f8fafc 0%, #e3f2fd 100%);
    padding-top: 80px;
}

.hero-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-title {
    color: #2c3e50;
    margin-bottom: 0.5rem;
    font-size: 4rem;
    font-weight: 700;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: #3498db;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.hero-description {
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 2.5rem;
    line-height: 1.8;
}

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

.hero-image {
    text-align: center;
}

.profile-image {
    width: 300px;
    height: 300px;
    border-radius: 20px;
    object-fit: cover;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.profile-image:hover {
    transform: translateY(-5px);
}

/* About Section */
.about {
    background: #f8f9fa;
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: left;
}

.about-content p {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
}

/* Experience Section */
.experience {
    background: white;
}

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

.timeline::before {
    content: '';
    position: absolute;
    width: 2px;
    background: linear-gradient(to bottom, #3498db, #2ecc71);
    top: 0;
    bottom: 0;
    left: 30px;
}

.timeline-item {
    position: relative;
    margin: 2rem 0;
    padding-left: 80px;
}

.timeline-marker {
    position: absolute;
    width: 16px;
    height: 16px;
    background: #3498db;
    border: 4px solid white;
    border-radius: 50%;
    left: 22px;
    top: 10px;
    box-shadow: 0 0 0 4px #e3f2fd;
}

.timeline-content {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    border-left: 4px solid #3498db;
}

.timeline-header {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    margin-bottom: 1rem;
}

.company-logo {
    width: 60px;
    height: 60px;
    object-fit: contain;
    background: #f8f9fa;
    border-radius: 8px;
    padding: 8px;
}

.timeline-info h3 {
    color: #2c3e50;
    margin-bottom: 0.25rem;
}

.timeline-info h4 {
    color: #3498db;
    font-weight: 500;
    margin-bottom: 0.25rem;
}

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

/* Research Section */
.research {
    background: #f8f9fa;
}

.research-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.research-content p {
    font-size: 1.1rem;
    margin-bottom: 2rem;
}

.research-areas {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.research-area {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    text-align: center;
    transition: transform 0.3s ease;
}

.research-area:hover {
    transform: translateY(-5px);
}

.research-area h3 {
    color: #2c3e50;
    margin-bottom: 1rem;
}

/* Publications Section */
.publications {
    background: white;
}

.publications-grid {
    display: grid;
    gap: 3rem;
    max-width: 1000px;
    margin: 0 auto;
}

.publication-card {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 2rem;
    background: #f8f9fa;
    border-radius: 12px;
    padding: 2rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.publication-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.publication-image img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 8px;
}

.publication-title {
    font-size: 1.3rem;
    margin-bottom: 0.75rem;
}

.publication-title a {
    color: #2c3e50;
    text-decoration: none;
}

.publication-title a:hover {
    color: #3498db;
}

.publication-authors {
    color: #666;
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

.publication-venue {
    color: #3498db;
    font-weight: 600;
    margin-bottom: 1rem;
}

.publication-description {
    color: #555;
    margin-bottom: 1rem;
    line-height: 1.6;
}

.publication-award {
    display: inline-block;
    background: #e8f5e8;
    color: #27ae60;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

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

.link {
    color: #3498db;
    font-weight: 500;
    text-decoration: none;
    padding: 0.25rem 0;
    border-bottom: 1px solid transparent;
    transition: border-color 0.3s ease;
}

.link:hover {
    border-bottom-color: #3498db;
}

.publications-note {
    text-align: center;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid #eee;
}

/* Contact Section */
.contact {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.contact .section-title {
    color: white;
}

.contact .section-title::after {
    background: white;
}

.contact-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.contact-content p {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.2rem;
    margin-bottom: 2rem;
}

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

.contact-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: white;
    text-decoration: none;
    padding: 1rem 1.5rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: all 0.3s ease;
}

.contact-link:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

/* Footer */
.footer {
    background: #2c3e50;
    color: #bdc3c7;
    text-align: center;
    padding: 2rem 0;
}

.footer a {
    color: #3498db;
}

.footer-note {
    margin-top: 1rem;
    font-size: 0.9rem;
    opacity: 0.8;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-links {
        justify-content: center;
    }

    .profile-image {
        width: 250px;
        height: 250px;
    }

    .timeline::before {
        left: 20px;
    }

    .timeline-item {
        padding-left: 60px;
    }

    .timeline-marker {
        left: 12px;
    }

    .timeline-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }

    .research-areas {
        grid-template-columns: 1fr;
    }

    .publication-card {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .contact-links {
        flex-direction: column;
        align-items: center;
    }

    .contact-link {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }

    section {
        padding: 1rem 0;
    }

    h1 {
        font-size: 2.5rem;
    }

    h2 {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .hero-description {
        font-size: 1rem;
    }

    .btn {
        padding: 0.6rem 1.2rem;
        font-size: 0.85rem;
    }

    .timeline-content {
        padding: 1.5rem;
    }

    .publication-card {
        padding: 1.5rem;
    }

    .research-area {
        padding: 1.5rem;
    }
}

/* Animation Classes */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

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

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #1a1a1a;
        --text-color: #e0e0e0;
        --card-bg: #2d2d2d;
    }
}