/* Google-inspired Clean Design */
:root {
    --primary-color: #1a73e8;
    --text-color: #202124;
    --text-secondary: #5f6368;
    --bg-color: #ffffff;
    --bg-secondary: #f8f9fa;
    --border-color: #dadce0;
    --shadow-sm: 0 1px 2px 0 rgba(60, 64, 67, 0.3), 0 1px 3px 1px rgba(60, 64, 67, 0.15);
    --shadow-md: 0 4px 6px rgba(60, 64, 67, 0.3);
    --font-family: 'Google Sans', 'Roboto', Arial, sans-serif;
    --max-width: 1200px;
}

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

body {
    font-family: var(--font-family);
    color: var(--text-color);
    background-color: var(--bg-color);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 400;
    color: var(--text-color);
    margin-bottom: 1rem;
}

h1 {
    font-size: 3.5rem;
    line-height: 1.2;
    font-weight: 500;
}

h2 {
    font-size: 2.25rem;
    margin-bottom: 2rem;
    text-align: center;
    position: relative;
    padding-bottom: 1rem;
}

h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background-color: var(--primary-color);
    border-radius: 2px;
}

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

a {
    text-decoration: none;
    color: var(--primary-color);
    transition: color 0.3s ease;
}

a:hover {
    color: #174ea6;
}

/* Layout Utilities */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 2rem;
}

.section {
    padding: 5rem 0;
}

.bg-light {
    background-color: var(--bg-secondary);
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.98);
    box-shadow: 0 1px 6px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    padding: 1rem 0;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--text-color);
}

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

.nav-links a {
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 1rem;
}

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

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-color);
}

/* Hero Section */
.hero {
    padding-top: 160px;
    padding-bottom: 100px;
    text-align: center;
    background: linear-gradient(180deg, rgba(26, 115, 232, 0.05) 0%, rgba(255, 255, 255, 0) 100%);
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.profile-img-container {
    width: 180px;
    height: 180px;
    margin: 0 auto 2rem;
    border-radius: 50%;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    border: 4px solid #fff;
}

.profile-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    background-color: #eee;
    /* Placeholder color */
}

.tagline {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    font-weight: 300;
}

.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    border-radius: 4px;
    font-weight: 500;
    transition: all 0.3s ease;
    border: 1px solid transparent;
}

.btn-primary {
    background-color: var(--primary-color);
    color: #fff;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

.btn-primary:hover {
    background-color: #174ea6;
    color: #fff;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
    transform: translateY(-1px);
}

.btn-outline {
    background-color: transparent;
    color: var(--primary-color);
    border-color: var(--border-color);
    margin-left: 1rem;
}

.btn-outline:hover {
    background-color: rgba(26, 115, 232, 0.04);
    border-color: var(--primary-color);
}

/* About Section */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: start;
}

.about-text {
    font-size: 1.1rem;
}

.education-list {
    list-style: none;
}

.education-item {
    margin-bottom: 1.5rem;
    padding-left: 1.5rem;
    border-left: 3px solid var(--primary-color);
}

.education-item h4 {
    margin-bottom: 0.25rem;
    font-weight: 600;
}

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

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

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 2px;
    background-color: var(--border-color);
}

.timeline-item {
    margin-bottom: 3rem;
    padding-left: 2rem;
    position: relative;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -5px;
    top: 6px;
    width: 12px;
    height: 12px;
    background-color: #fff;
    border: 2px solid var(--primary-color);
    border-radius: 50%;
}

.timeline-content h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.timeline-content .org {
    font-weight: 500;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    display: block;
}

.timeline-content .date {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
    display: block;
}

/* Research Section */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.research-card {
    background: #fff;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 2rem;
    transition: box-shadow 0.3s ease;
}

.research-card:hover {
    box-shadow: var(--shadow-sm);
    border-color: transparent;
}

.research-card h3 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1.5rem;
}

.tag {
    background-color: #e8f0fe;
    color: #1967d2;
    padding: 0.25rem 0.75rem;
    border-radius: 16px;
    font-size: 0.85rem;
    font-weight: 500;
}

/* Contact Section */
.contact-container {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

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

.contact-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.1rem;
    padding: 1rem 2rem;
    background-color: #fff;
    border: 1px solid var(--border-color);
    border-radius: 50px;
    color: var(--text-color);
}

.contact-item:hover {
    background-color: #f8f9fa;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

/* Footer */
footer {
    background-color: #fff;
    border-top: 1px solid var(--border-color);
    padding: 2rem 0;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
    h1 {
        font-size: 2.5rem;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: #fff;
        flex-direction: column;
        padding: 1rem 0;
        box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
        text-align: center;
    }

    .nav-links.active {
        display: flex;
    }

    .mobile-menu-btn {
        display: block;
    }

    .about-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .hero-actions {
        display: flex;
        flex-direction: column;
        gap: 1rem;
        align-items: center;
    }

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