/* Variables for Light and Dark Modes */
:root {
    --bg-color: #ffffff;
    --text-main: #1a1a1a;
    --text-muted: #555555;
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --card-bg: #f8fafc;
    --border-color: #e2e8f0;
    --font-heading: 'Playfair Display', serif;
    --font-body: 'Inter', sans-serif;
}

body.dark-mode {
    --bg-color: #0f172a;
    --text-main: #f8fafc;
    --text-muted: #cbd5e1;
    --primary-color: #3b82f6;
    --card-bg: #1e293b;
    --border-color: #334155;
}

/* Base Reset */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    cursor: default; /* Keep default cursor, UAV follows it */
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    font-family: var(--font-body);
    line-height: 1.7;
    transition: background-color 0.3s, color 0.3s;
    overflow-x: hidden;
}

/* Typography */
h1, h2, h3, .logo {
    font-family: var(--font-heading);
    color: var(--text-main);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Header & Nav */
header {
    padding: 1.5rem 0;
    position: sticky;
    top: 0;
    background-color: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    z-index: 100;
    border-bottom: 1px solid var(--border-color);
}

body.dark-mode header {
    background-color: rgba(15, 23, 42, 0.9);
}

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

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 0.5px;
}

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

.nav-links a {
    text-decoration: none;
    color: var(--text-muted);
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.2s;
    cursor: pointer;
}

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

#btn-theme {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.2rem;
    cursor: pointer;
}

/* Hero Section */
.hero {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    padding: 6rem 2rem;
}

.role-badge {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.85rem;
    letter-spacing: 1px;
    text-transform: uppercase;
}

.hero h1 {
    font-size: 3.5rem;
    margin: 1rem 0;
    line-height: 1.1;
}

.hero p {
    color: var(--text-muted);
    font-size: 1.1rem;
    margin-bottom: 2.5rem;
    max-width: 90%;
}

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

.btn {
    padding: 0.8rem 1.5rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: all 0.2s;
    cursor: pointer;
}

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

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

.btn-secondary {
    background-color: transparent;
    color: var(--text-main);
    border: 2px solid var(--border-color);
}

.btn-secondary:hover {
    border-color: var(--text-main);
}

/* Hero Image Wrapper */
.hero-image-wrapper {
    position: relative;
}

.image-backdrop {
    position: absolute;
    top: 20px;
    left: -20px;
    width: 100%;
    height: 100%;
    background-color: #eef2ff;
    border-radius: 12px;
    z-index: -1;
}

body.dark-mode .image-backdrop {
    background-color: #1e293b;
}

.profile-img {
    width: 100%;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    display: block;
}

/* Education and Research Details Section */
.details-section {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 4rem;
    padding: 4rem 2rem 8rem 2rem;
}

h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
}

/* Education Cards */
.edu-card {
    display: flex;
    gap: 1.5rem;
    background-color: var(--card-bg);
    padding: 1.5rem;
    border-radius: 10px;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border-color);
}

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

.edu-info h3 {
    font-size: 1.1rem;
    font-family: var(--font-body);
    margin-bottom: 0.3rem;
}

.edu-info .university {
    color: var(--text-muted);
    font-size: 0.95rem;
}

.edu-info .date {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-top: 0.5rem;
}

/* Research Interests */
.interest-list {
    list-style: none;
}

.interest-list li {
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 1.05rem;
}

.interest-list li:first-child {
    padding-top: 0;
}

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

/* Custom BWB UAV Cursor */
#uav-cursor {
    position: fixed;
    top: 0;
    left: 0;
    width: 30px;
    height: 30px;
    pointer-events: none; /* Allows you to click through it */
    z-index: 9999;
    transform-origin: center;
    will-change: transform;
    opacity: 0.8;
}

/* Responsive */
@media (max-width: 768px) {
    .hero {
        grid-template-columns: 1fr;
        padding: 3rem 2rem;
    }
    .details-section {
        grid-template-columns: 1fr;
    }
    .nav-links {
        display: none; /* Add a hamburger menu for mobile later */
    }
}