/* General Styling & Variables */
:root {
    --primary-color: #0d2c4e; /* Dark Blue */
    --secondary-color: #f4f4f4; /* Light Gray */
    --accent-color: #3498db; /* Bright Blue */
    --text-color: #333;
    --light-text: #fff;
    --heading-font: 'Montserrat', sans-serif;
    --body-font: 'Lato', sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--body-font);
    line-height: 1.6;
    color: var(--text-color);
    background-color: #fff;
}

.container {
    max-width: 1100px;
    margin: auto;
    overflow: hidden;
    padding: 0 2rem;
}

h1, h2, h3 {
    font-family: var(--heading-font);
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

h1 { font-size: 3rem; }
h2 { font-size: 2.5rem; text-align: center; margin-bottom: 2rem; }
h3 { font-size: 1.8rem; }

p {
    margin-bottom: 1rem;
}

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

/* Header & Navigation */
header {
    background: #fff;
    color: var(--primary-color);
    padding: 1rem 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    border-bottom: 3px solid var(--accent-color);
}

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

header .logo {
    font-size: 1.5rem;
    font-weight: bold;
}

header nav ul {
    display: flex;
    list-style: none;
}

header nav ul li {
    margin-left: 1.5rem;
}

header nav a {
    color: var(--primary-color);
    font-weight: bold;
    transition: color 0.3s ease;
}

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

/* Sections */
section {
    padding: 6rem 0;
}

section:nth-child(odd) {
    background-color: var(--secondary-color);
}

/* Home Section */
#home {
    background: linear-gradient(rgba(13, 44, 78, 0.7), rgba(13, 44, 78, 0.7)), url('https://images.unsplash.com/photo-1579546929518-9e396f3cc809?q=80&w=2070&auto=format&fit=crop') no-repeat center center/cover;
    color: var(--light-text);
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding-top: 0;
}

#home h1, #home h2 {
    color: var(--light-text);
}

#home h2 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

#home .summary {
    font-size: 1.2rem;
    max-width: 800px;
    margin: 1rem auto;
}

.cta-buttons {
    margin-top: 2rem;
}

.btn {
    display: inline-block;
    background: var(--accent-color);
    color: var(--light-text);
    padding: 0.8rem 2rem;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.3s ease;
    margin: 0 0.5rem;
}

.btn:hover {
    background-color: #2980b9;
}

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

.btn-secondary:hover {
    background: var(--accent-color);
    border-color: var(--accent-color);
}

/* About Section */
#about .about-content ul {
    list-style: none;
    margin-top: 1rem;
}

#about .about-content li {
    background: #fff;
    padding: 1rem;
    margin-bottom: 0.5rem;
    border-left: 5px solid var(--accent-color);
}

#about .btn {
    margin-top: 2rem;
    background: var(--primary-color);
}
#about .btn:hover {
    background: #1a4a81;
}

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

.card {
    background: #fff;
    padding: 2rem;
    border-radius: 5px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
}

.card h3 {
    margin-bottom: 1rem;
}

.card p:last-child {
    margin-bottom: 0;
}

.card b {
    color: var(--primary-color);
}

/* Publications Section */
.publication-list {
    list-style: none;
    margin-left: 1rem;
}

.publication-list li {
    padding: 0.5rem 0;
    border-bottom: 1px solid #ddd;
}
.publication-list li:before {
    content: '▪';
    margin-right: 10px;
    color: var(--accent-color);
}

/* Contact Section */
#contact .contact-info, #contact .social-links {
    text-align: center;
}

#contact .contact-info p {
    font-size: 1.2rem;
    margin: 0.5rem 0;
}

#contact .contact-info i {
    color: var(--primary-color);
    margin-right: 10px;
}

#contact .social-links {
    margin-top: 2rem;
}

#contact .social-links a {
    font-size: 2.5rem;
    margin: 0 1rem;
    color: var(--primary-color);
    transition: color 0.3s ease;
}

#contact .social-links a:hover {
    color: var(--accent-color);
}

/* Footer */
footer {
    background: var(--primary-color);
    color: var(--light-text);
    text-align: center;
    padding: 2rem 0;
}

/* Responsive Design */
@media(max-width: 768px) {
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }
    
    header .container {
        flex-direction: column;
    }
    header .logo {
        margin-bottom: 1rem;
    }
    header nav ul {
        padding: 0;
    }
    header nav ul li {
        margin: 0 0.5rem;
    }
    
    #home {
        height: auto;
        padding-top: 8rem;
        padding-bottom: 4rem;
    }
}


.project-grid {
    align-items: stretch;
}

.card {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    height: 100%;
}