/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;600;700&family=Playfair+Display:wght@700&display=swap');

:root {
    --primary: #2563EB; /* Electric Blue */
    --primary-dark: #1d4ed8;
    --primary-light: #60a5fa;
    --text-main: #1f2937;
    --text-light: #6b7280;
    --bg-body: #f9fafb;
    --bg-card: #ffffff;
    --bg-alt: #f3f4f6;
    --border: #e5e7eb;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius: 0.75rem;
    --transition: all 0.3s ease;
}

/* Dark Mode Support (System preference) */
@media (prefers-color-scheme: dark) {
    :root {
        --text-main: #f3f4f6;
        --text-light: #9ca3af;
        --bg-body: #0f172a;
        --bg-card: #1e293b;
        --bg-alt: #111827;
        --border: #374151;
    }
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-body);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Playfair Display', serif; /* Elegant heading font to contrast user's technical field */
    font-family: 'Inter', sans-serif; /* Sticking to clean sans-serif for modern tech look as per request, can switch if desired */
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

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

a:hover {
    color: var(--primary-dark);
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    display: block;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background-color: var(--primary);
    color: white;
    border-radius: var(--radius);
    font-weight: 600;
    border: 2px solid var(--primary);
    cursor: pointer;
    transition: var(--transition);
}

.btn:hover {
    background-color: var(--primary-dark);
    border-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
    color: white;
}

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

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

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Header & Nav */
header {
    background-color: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: 0 1px 2px rgba(0,0,0,0.05);
}

@media (prefers-color-scheme: dark) {
    header {
        background-color: rgba(15, 23, 42, 0.9);
    }
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-main);
}

.logo span {
    color: var(--primary);
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: var(--text-main);
    font-weight: 500;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -4px;
    left: 0;
    background-color: var(--primary);
    transition: var(--transition);
}

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

.menu-toggle {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-main);
}

/* Hero Section */
.hero {
    padding: 120px 0 80px;
    min-height: 90vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.05) 0%, rgba(37, 99, 235, 0.0) 100%);
}

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

.hero-text h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
}

.hero-text h1 span {
    color: var(--primary);
    position: relative;
    display: inline-block;
}

.hero-text .role {
    font-size: 1.5rem;
    color: var(--text-light);
    margin-bottom: 1.5rem;
    font-weight: 400;
}

.hero-text p {
    font-size: 1.125rem;
    color: var(--text-light);
    margin-bottom: 2rem;
    max-width: 500px;
}

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

.hero-img {
    position: relative;
    display: flex;
    justify-content: center;
}

.hero-img img {
    border-radius: 50%;
    width: 350px;
    height: 350px;
    object-fit: cover;
    border: 5px solid var(--bg-card);
    box-shadow: var(--shadow-hover);
    z-index: 2;
    animation: float 6s ease-in-out infinite;
}

.blob-bg {
    position: absolute;
    width: 400px;
    height: 400px;
    background-color: var(--primary);
    opacity: 0.1;
    border-radius: 50%;
    z-index: 1;
    filter: blur(50px);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

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

/* Section Common */
section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.section-header .subtitle {
    display: block;
    color: var(--primary);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 2px;
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
}

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

.skill-card {
    background-color: var(--bg-card);
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid var(--border);
}

.skill-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
    border-color: var(--primary);
}

.skill-icon {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 1rem;
}

.skill-card h3 {
    margin-bottom: 1rem;
    font-size: 1.25rem;
}

.skill-list li {
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    color: var(--text-light);
}

.skill-list li::before {
    content: '•';
    color: var(--primary);
    font-weight: bold;
    margin-right: 0.5rem;
}

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

.timeline::after {
    content: '';
    position: absolute;
    width: 2px;
    background-color: var(--border);
    top: 0;
    bottom: 0;
    left: 20px;
    margin-left: -1px;
}

.timeline-item {
    position: relative;
    padding-left: 50px;
    margin-bottom: 3rem;
}

.timeline-dot {
    position: absolute;
    width: 20px;
    height: 20px;
    background-color: var(--bg-card);
    border: 4px solid var(--primary);
    border-radius: 50%;
    left: 10px;
    top: 5px;
    z-index: 10;
}

.timeline-content h3 {
    font-size: 1.5rem;
    color: var(--text-main);
}

.timeline-content .company {
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 0.25rem;
}

.timeline-content .date {
    font-size: 0.875rem;
    color: var(--text-light);
    margin-bottom: 1rem;
    font-style: italic;
}

.timeline-content ul {
    margin-left: 1rem;
}

.timeline-content li {
    margin-bottom: 0.5rem;
    list-style-type: disc;
    color: var(--text-light);
}

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

.project-card {
    background-color: var(--bg-card);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid var(--border);
}

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

.project-img {
    height: 200px;
    background-color: var(--bg-alt);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    font-size: 3rem;
}

.project-content {
    padding: 1.5rem;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.tag {
    font-size: 0.75rem;
    background-color: rgba(37, 99, 235, 0.1);
    color: var(--primary);
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-weight: 600;
}

.project-card h3 {
    margin-bottom: 0.5rem;
}

.project-card p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
}

/* Contact Footer */
.footer {
    background-color: var(--bg-alt);
    padding: 60px 0 20px;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-bottom: 3rem;
}

.contact-info h3 {
    margin-bottom: 1.5rem;
}

.contact-item {
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
    color: var(--text-light);
}

.contact-item i {
    width: 24px;
    color: var(--primary);
    margin-right: 1rem;
}

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

.social-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--bg-card);
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.social-btn:hover {
    background-color: var(--primary);
    color: white;
    transform: translateY(-3px);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
    color: var(--text-light);
    font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background-color: var(--bg-card);
        flex-direction: column;
        padding: 2rem;
        box-shadow: var(--shadow);
        text-align: center;
    }

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

    .menu-toggle {
        display: block;
    }

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

    .hero-text h1 {
        font-size: 2.5rem;
    }
    
    .hero-text p {
        margin: 0 auto 2rem;
    }

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

    .footer-content {
        grid-template-columns: 1fr;
    }

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

/* Education & Research Grid */
.education-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}