/* Modern Portfolio Styles */
:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #3b82f6;
    --accent: #60a5fa;
    --background: #ffffff;
    --surface: #f8fafc;
    --text-primary: #1e293b;
    --text-secondary: #475569;
    --success: #22c55e;
    --warning: #eab308;
    --error: #ef4444;
}

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

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Space Grotesk', sans-serif;
    font-weight: 700;
    line-height: 1.2;
}

/* Navigation */
.navbar {
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    padding: 1rem 0;
}

.nav-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
}

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

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
}

.nav-links a:hover, .nav-links a.active {
    color: var(--primary);
    background: rgba(37, 99, 235, 0.1);
}

.contact-btn {
    background: var(--primary);
    color: white !important;
    padding: 0.5rem 1.5rem;
    border-radius: 0.5rem;
    transition: background 0.3s ease;
}

.contact-btn:hover {
    background: var(--primary-dark);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    padding: 8rem 2rem 4rem;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
}

.hero-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-content {
    padding-right: 2rem;
}

.hero-subtitle {
    color: var(--primary);
    font-weight: 600;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.hero h1 {
    font-size: 4rem;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero h2 {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.primary-btn, .secondary-btn {
    padding: 0.75rem 2rem;
    border-radius: 0.5rem;
    font-weight: 600;
    text-decoration: none;
    transition: transform 0.3s ease;
}

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

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

.primary-btn:hover, .secondary-btn:hover {
    transform: translateY(-2px);
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.social-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: white;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    text-decoration: none;
    transition: all 0.3s ease;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

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

/* Profile Image */
.profile-container {
    position: relative;
    width: 400px;
    height: 400px;
    margin: 0 auto;
}

.profile-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 2rem;
    position: relative;
    z-index: 2;
}

.profile-bg {
    position: absolute;
    top: 2rem;
    left: 2rem;
    width: 100%;
    height: 100%;
    background: var(--primary);
    border-radius: 2rem;
    z-index: 1;
}

/* Sections */
section {
    padding: 6rem 2rem;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* About Section */
.about-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.highlight-text {
    font-size: 1.25rem;
    color: var(--primary);
    margin-bottom: 1.5rem;
    font-weight: 500;
}

.skills-container {
    margin-top: 2rem;
}

.skills-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1rem;
}

.skill-tag {
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    font-size: 0.9rem;
}

/* Research Cards */
.research-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.research-card {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

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

.card-icon {
    width: 60px;
    height: 60px;
    background: rgba(37, 99, 235, 0.1);
    border-radius: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.card-icon i {
    font-size: 1.5rem;
    color: var(--primary);
}

/* Experience Cards */
.experience-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.experience-card {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

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

.date {
    color: var(--primary);
    font-weight: 500;
}

.institution {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.experience-details {
    list-style: none;
}

.experience-details li {
    margin-bottom: 0.5rem;
    position: relative;
    padding-left: 1.5rem;
}

.experience-details li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.5rem;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--primary);
}

/* Publications */
.publications-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
}

.publication-card {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.publication-tags {
    display: flex;
    gap: 0.5rem;
    margin-top: 1rem;
}

.tag {
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.8rem;
}

/* Contact Section */
.contact {
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
}

.contact-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 4rem;
}

.contact-card {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    text-align: center;
    margin-bottom: 2rem;
}

.contact-card i {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 1rem;
}

.contact-form {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 1rem;
    border: 1px solid #e2e8f0;
    border-radius: 0.5rem;
    font-family: inherit;
}

.form-group textarea {
    height: 150px;
    resize: vertical;
}

.submit-btn {
    background: var(--primary);
    color: white;
    padding: 1rem 2rem;
    border: none;
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s ease;
}

.submit-btn:hover {
    background: var(--primary-dark);
}

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

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

.footer-social {
    display: flex;
    gap: 1rem;
}

.footer-social a {
    color: white;
    font-size: 1.25rem;
    transition: opacity 0.3s ease;
}

.footer-social a:hover {
    opacity: 0.8;
}