/* 1. RESET & VARIABLES */
:root {
    --primary: #0f172a;      /* Dark Slate - Professional Base */
    --accent: #0ea5e9;       /* Sky Blue - Highlights */
    --bg-light: #f8fafc;     /* Very light grey for contrast */
    --text-main: #334155;    /* Dark Grey for readability */
    --text-light: #64748b;   /* Lighter grey for subtext */
    --white: #ffffff;
    --nav-height: 70px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

html { scroll-behavior: smooth; }

body {
    font-family: 'Inter', sans-serif;
    margin: 0;
    padding: 0;
    color: var(--text-main);
    line-height: 1.6;
    padding-top: var(--nav-height); /* Prevent content hiding behind fixed nav */
}

a { text-decoration: none; color: inherit; transition: 0.3s; }
ul { list-style: none; padding: 0; }

/* 2. NAVIGATION (THE HORIZONTAL BAR) */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    height: var(--nav-height);
    background: var(--white);
    border-bottom: 1px solid #e2e8f0;
    z-index: 1000;
    display: flex;
    align-items: center;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

.nav-container {
    width: 90%;
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--primary);
}

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

.nav-links a {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-main);
}

.nav-links a:hover { color: var(--accent); }

.nav-socials {
    display: flex;
    gap: 15px;
    border-left: 1px solid #e2e8f0;
    padding-left: 20px;
}

.nav-socials a {
    font-size: 1.2rem;
    color: var(--text-light);
}

.nav-socials a:hover { color: var(--accent); transform: translateY(-2px); }

.hamburger { display: none; cursor: pointer; }

/* 3. HERO SECTION */
.hero {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 4rem 1rem;
    background: var(--bg-light);
}

.hero-content {
    max-width: 1100px;
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 3rem;
}

.hero-text { flex: 1; }

.hero-text h1 {
    font-size: 3rem;
    line-height: 1.2;
    color: var(--primary);
    margin-bottom: 1rem;
}

.highlight { color: var(--accent); }

.badge {
    display: inline-block;
    background: #e0f2fe;
    color: #0369a1;
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.hero-image img {
    width: 280px;
    height: 280px;
    object-fit: cover;
    border-radius: 20px; /* Modern Rounded Square, not Circle */
    box-shadow: 20px 20px 0 var(--accent); /* Cool Design Element */
}

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

.btn {
    padding: 10px 24px;
    border-radius: 6px;
    font-weight: 600;
    cursor: pointer;
}

.btn.primary { background: var(--primary); color: white; }
.btn.primary:hover { background: #1e293b; }

.btn.secondary { border: 2px solid #cbd5e1; color: var(--text-main); }
.btn.secondary:hover { border-color: var(--text-main); }

/* 4. SECTIONS & CARDS */
.section { padding: 4rem 1rem; }
.bg-light { background: var(--bg-light); }

.container { max-width: 1000px; margin: 0 auto; }
.section-title {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 2.5rem;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    display: block;
    width: 50%;
    height: 4px;
    background: var(--accent);
    margin-top: 5px;
}

/* Timeline */
.timeline-item {
    display: flex;
    margin-bottom: 2rem;
    gap: 2rem;
}

.timeline-date {
    min-width: 150px;
    font-weight: 600;
    color: var(--text-light);
    text-align: right;
}

.timeline-content h3 { margin: 0; color: var(--primary); }
.timeline-content h4 { margin: 0.2rem 0; font-weight: 500; color: var(--accent); }
.timeline-content p { margin-top: 0.5rem; font-size: 0.95rem; }

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

.project-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: transform 0.3s;
    border: 1px solid #f1f5f9;
}

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

.card-image img { width: 100%; height: 200px; object-fit: cover; }
.card-content { padding: 1.5rem; }
.card-content h3 { margin: 0 0 0.5rem 0; font-size: 1.25rem; }

.tag.patent {
    background: #fef3c7;
    color: #d97706;
    padding: 3px 8px;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
}

.tech-stack { margin-top: 1rem; display: flex; gap: 0.5rem; flex-wrap: wrap; }
.tech-stack span {
    background: #f1f5f9;
    padding: 4px 10px;
    border-radius: 4px;
    font-size: 0.8rem;
    color: var(--text-light);
}

/* 5. SKILLS & FOOTER */
.split-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 4rem; }
.skill-group { margin-bottom: 1.5rem; }
.skill-group strong { display: block; color: var(--primary); margin-bottom: 0.3rem; }
.awards-list li { margin-bottom: 1rem; }

.center-text { text-align: center; }
.education-block { margin-bottom: 2rem; }

footer {
    background: var(--primary);
    color: white;
    padding: 2rem 0;
    text-align: center;
}

.footer-socials { margin-top: 1rem; }
.footer-socials a { color: #94a3b8; margin: 0 10px; }
.footer-socials a:hover { color: white; }

/* 6. RESPONSIVE MOBILE */
@media (max-width: 768px) {
    .hero-content { flex-direction: column-reverse; text-align: center; }
    .hero-image img { width: 200px; height: 200px; margin-bottom: 1rem; box-shadow: none; border: 4px solid white; }
    .split-layout { grid-template-columns: 1fr; gap: 2rem; }
    .timeline-item { flex-direction: column; gap: 0.5rem; }
    .timeline-date { text-align: left; }
    
    .nav-links {
        display: none;
        position: absolute;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background: white;
        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; }
    .nav-socials { display: none; } /* Hide socials in nav on small mobile to save space */
    .hamburger { display: block; font-size: 1.5rem; }
}
.coursework-section {
    margin-top: 40px;
}

.section-title {
    font-size: 28px;
    margin-bottom: 20px;
    font-weight: 700;
}

.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 15px;
}

.course-card {
    padding: 12px 18px;
    background: #f5f5f5;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 500;
    border-left: 4px solid #4a90e2;
    transition: transform 0.15s ease-in-out, background 0.15s;
}

.course-card:hover {
    background: #e9f2ff;
    transform: translateY(-3px);
}