/* Reset and Base Styles */
:root {
    --bg-primary: #f4f4f4;
    --bg-secondary: white;
    --text-primary: #333;
    --text-secondary: #666;
    --border-color: rgba(0, 0, 0, 0.1);
    --shadow-color: rgba(0, 0, 0, 0.1);
    --header-bg: #2c3e50;
}

body.dark-mode {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --text-primary: #e0e0e0;
    --text-secondary: #b0b0b0;
    --border-color: rgba(255, 255, 255, 0.1);
    --shadow-color: rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Typography */
h1, h2, h3 {
    margin-bottom: 1rem;
}

p {
    margin-bottom: 1rem;
}

a {
    color: #007bff;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* Dark Mode Toggle */
.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    font-size: 1.2rem;
    background: none;
    border: 2px solid var(--text-primary);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    z-index: 1000;
    color: var(--text-primary);
}

.theme-toggle:hover {
    background-color: var(--text-primary);
    color: var(--bg-primary);
    transform: scale(1.1);
}

body.dark-mode .theme-toggle::after {
    content: '☀️';
    position: absolute;
}

body:not(.dark-mode) .theme-toggle::after {
    content: '';
}

/* Header and Navigation */
header {
    background-color: #2c3e50;
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

nav h1 {
    font-size: 1.5rem;
    margin: 0;
}

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

nav a {
    color: white;
}

nav a:hover {
    color: #007bff;
    text-decoration: none;
}

/* Main Content */
main {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 1rem;
    margin-top: 6rem;
}

section {
    background-color: var(--bg-secondary);
    padding: 2rem;
    margin-bottom: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px var(--shadow-color);
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

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

.profile-pic {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 1.5rem;
    border: 4px solid white;
    box-shadow: 0 4px 15px var(--shadow-color);
    transition: box-shadow 0.3s ease;
}

.name {
    font-size: 2rem;
    color: white;
    margin-bottom: 1rem;
}

/* Footer */
footer {
    background-color: #2c3e50;
    color: white;
    text-align: center;
    padding: 2rem 1rem;
    margin-top: 3rem;
    transition: background-color 0.3s ease;
}

body.dark-mode footer {
    background-color: #1a1a1a;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

/* Responsive Design */
@media (max-width: 768px) {
    nav {
        flex-direction: column;
        gap: 1rem;
    }

    nav ul {
        gap: 1rem;
    }

    .hero h2 {
        font-size: 1.8rem;
    }

    section {
        padding: 1.5rem;
    }
}


#research {
    margin-top: 40px;
}

#research h2 {
    margin-bottom: 20px;
}

#research h3 {
    margin-top: 30px;     /* space above subsection */
    margin-bottom: 10px;  /* space before list */
    color: #555;          /* slightly grey */
    font-weight: 600;
}

#research ul {
    margin-top: 0;
    margin-bottom: 15px;
    padding-left: 20px;
}

#research li {
    margin-bottom: 8px;   /* spacing between items */
    line-height: 1.5;     /* better readability */
}

.contact-container {
    display: flex;
    justify-content: space-between; /* pushes left & right apart */
    align-items: flex-start;
}

.contact-left {
    max-width: 60%;
}

.contact-right i,
.contact-right span {
    margin-right: 6px;
}

.contact-right {
    display: flex;
    justify-content: flex-end;
}