:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --success-color: #10b981;
    --info-color: #3b82f6;
    --danger-color: #ef4444;
    --dark: #0f172a;
    --light: #f8fafc;
    --text-dark: #1e293b;
    --text-light: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.07), 0 10px 13px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 20px 25px rgba(0, 0, 0, 0.1), 0 10px 10px rgba(0, 0, 0, 0.04);
}

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

body {
    font-family: 'Poppins', sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--light);
}

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

/* Navigation */
.navbar {
    position: sticky;
    top: 0;
    background: white;
    box-shadow: var(--shadow);
    z-index: 100;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-links a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

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

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--primary-color);
}

/* Hero Section */
.hero {
    padding: 80px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

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

.hero-content {
    z-index: 2;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.hero-image-container {
    margin-bottom: 2rem;
}

.hero-image {
    width: 250px;
    height: 250px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid white;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s ease;
}

.hero-image:hover {
    transform: scale(1.05);
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    opacity: 0.9;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.8;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
}

.btn {
    padding: 12px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    cursor: pointer;
    display: inline-block;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    background: transparent;
    color: white;
    border-color: white;
}

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

/* Floating Cards Animation */
.hero-animation {
    position: relative;
    height: 400px;
}

.floating-card {
    position: absolute;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    padding: 20px 30px;
    border-radius: 12px;
    font-weight: 600;
    animation: float 6s ease-in-out infinite;
}

.floating-card:nth-child(1) {
    top: 20px;
    left: 20px;
    animation-delay: 0s;
}

.floating-card:nth-child(2) {
    top: 120px;
    right: 40px;
    animation-delay: 1s;
}

.floating-card:nth-child(3) {
    bottom: 20px;
    left: 80px;
    animation-delay: 2s;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-20px); }
}

/* Section Titles */
.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    text-align: center;
    color: var(--text-dark);
}

/* Research Section */
.research {
    padding: 60px 0;
    background: var(--light);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.research-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    border-left: 4px solid var(--primary-color);
}

.research-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.research-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.research-card h3 {
    font-size: 1.3rem;
    color: var(--text-dark);
}

.badge {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.badge-primary {
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-color);
}

.badge-success {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
}

.badge-info {
    background: rgba(59, 130, 246, 0.1);
    color: var(--info-color);
}

.research-card p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

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

.link {
    display: inline-block;
    padding: 8px 16px;
    background: var(--light);
    color: var(--primary-color);
    text-decoration: none;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 600;
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

.link:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* Projects Section */
.projects {
    padding: 60px 0;
    background: white;
}

.project-category {
    margin-bottom: 4rem;
}

.category-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 2rem;
    color: var(--text-dark);
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--primary-color);
}

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

.project-card {
    background: var(--light);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.project-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow);
    border-color: var(--primary-color);
}

.project-card h4 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.project-card .language {
    display: inline-block;
    font-size: 0.8rem;
    background: var(--primary-color);
    color: white;
    padding: 4px 8px;
    border-radius: 4px;
    margin-bottom: 1rem;
}

.project-card p {
    flex-grow: 1;
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 1rem;
    line-height: 1.6;
}

.project-card a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
}

.project-card a:hover {
    color: var(--secondary-color);
}

/* Contact Section */
.contact {
    padding: 60px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

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

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

.contact-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    text-align: center;
    transition: all 0.3s ease;
}

.contact-card:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-3px);
}

.contact-card h3 {
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.contact-card a {
    color: white;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
}

.contact-card a:hover {
    text-decoration: underline;
}

/* Footer */
.footer {
    background: var(--dark);
    color: white;
    text-align: center;
    padding: 2rem;
    font-size: 0.9rem;
}

.footer-note {
    margin-top: 0.5rem;
    opacity: 0.7;
    font-size: 0.85rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero .container {
        grid-template-columns: 1fr;
    }

    .hero-animation {
        display: none;
    }

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

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

    .hero-image {
        width: 200px;
        height: 200px;
    }

    .nav-links {
        gap: 1rem;
        font-size: 0.9rem;
    }

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

    .hero-buttons {
        flex-direction: column;
    }

    .btn {
        width: 100%;
        text-align: center;
    }

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

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

@media (max-width: 480px) {
    .nav-links {
        gap: 0.5rem;
        font-size: 0.8rem;
    }

    .hero-title {
        font-size: 1.5rem;
    }

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

    .hero-image {
        width: 150px;
        height: 150px;
    }

    .section-title {
        font-size: 1.5rem;
        margin-bottom: 2rem;
    }
}