/* Global Styles */
:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --light-color: #ecf0f1;
    --dark-color: #2c3e50;
    --text-color: #333;
    --text-light: #7f8c8d;
    --white: #fff;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

* {
    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-color);
    background-color: var(--light-color);
}

a {
    text-decoration: none;
    color: var(--secondary-color);
    transition: color 0.3s ease;
}

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

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* Header Styles */
header {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 30px 0;
    box-shadow: var(--shadow);
}

.header-content {
    display: flex;
    align-items: center;
    gap: 30px;
}

.profile-img {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
    border: 5px solid var(--white);
    box-shadow: var(--shadow);
}

.header-text h1 {
    font-size: 2.2rem;
    margin-bottom: 10px;
}

.header-text p {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Navigation Styles */
nav {
    background-color: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

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

nav ul li a {
    display: block;
    padding: 15px 20px;
    color: var(--dark-color);
    font-weight: 600;
    transition: all 0.3s ease;
}

nav ul li a:hover {
    color: var(--accent-color);
    background-color: var(--light-color);
}

nav ul li a.active {
    color: var(--white);
    background-color: var(--secondary-color);
}

/* Main Content Styles */
main {
    padding: 40px 0;
}

section {
    margin-bottom: 40px;
}

h2 {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--secondary-color);
}

h3 {
    font-size: 1.5rem;
    color: var(--dark-color);
    margin-bottom: 15px;
}

p {
    margin-bottom: 15px;
}

/* Quick Info Grid */
.quick-info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.info-card {
    background-color: var(--white);
    padding: 20px;
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.info-card h3 {
    color: var(--secondary-color);
    margin-bottom: 15px;
}

.info-card i {
    margin-right: 10px;
    color: var(--secondary-color);
}

/* Research Grid */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin: 30px 0;
}

.research-area {
    background-color: var(--white);
    padding: 20px;
    border-radius: 8px;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease;
}

.research-area:hover {
    transform: translateY(-5px);
}

.research-area h3 {
    display: flex;
    align-items: center;
    gap: 10px;
}

.research-area i {
    color: var(--secondary-color);
    font-size: 1.2rem;
}

/* Projects */
.project {
    background-color: var(--white);
    padding: 20px;
    margin-bottom: 20px;
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.project-meta {
    color: var(--text-light);
    font-style: italic;
    margin-bottom: 15px;
}

/* News */
.news-item {
    background-color: var(--white);
    padding: 20px;
    margin-bottom: 20px;
    border-radius: 8px;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--secondary-color);
}

.news-date {
    color: var(--text-light);
    font-style: italic;
    margin-bottom: 10px;
}

/* Philosophy Grid */
.philosophy-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin: 30px 0;
}

.philosophy-point {
    background-color: var(--white);
    padding: 20px;
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.philosophy-point h3 {
    display: flex;
    align-items: center;
    gap: 10px;
}

.philosophy-point i {
    color: var(--secondary-color);
    font-size: 1.2rem;
}

/* Tables */
.course-table, .student-table {
    width: 100%;
    overflow-x: auto;
    margin: 20px 0;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    box-shadow: var(--shadow);
}

th, td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid #ddd;
}

th {
    background-color: var(--secondary-color);
    color: var(--white);
    font-weight: 600;
}

tr:nth-child(even) {
    background-color: #f2f2f2;
}

tr:hover {
    background-color: #e6f7ff;
}

/* Course List */
.course-list {
    list-style-type: none;
    margin: 20px 0;
}

.course-list li {
    padding: 10px 15px;
    margin-bottom: 5px;
    background-color: var(--white);
    border-left: 4px solid var(--secondary-color);
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    margin: 30px 0;
}

.stat-card {
    background-color: var(--white);
    padding: 20px;
    border-radius: 8px;
    box-shadow: var(--shadow);
    text-align: center;
}

.stat-card h3 {
    font-size: 2.5rem;
    color: var(--secondary-color);
    margin-bottom: 10px;
}

.scholar-link {
    text-align: center;
    margin-bottom: 30px;
}

/* Publication Tabs */
.publication-tabs {
    display: flex;
    margin-bottom: 20px;
    border-bottom: 1px solid #ddd;
}

.tab-button {
    padding: 10px 20px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-light);
    transition: all 0.3s ease;
}

.tab-button:hover {
    color: var(--secondary-color);
}

.tab-button.active {
    color: var(--secondary-color);
    border-bottom: 3px solid var(--secondary-color);
}

.tab-content {
    display: none;
}

.publication {
    background-color: var(--white);
    padding: 20px;
    margin-bottom: 20px;
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.authors, .journal {
    color: var(--text-light);
    font-style: italic;
    margin-bottom: 5px;
}

/* Footer Styles */
footer {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 30px 0;
    text-align: center;
}

.social-links {
    margin-top: 20px;
}

.social-links a {
    color: var(--white);
    font-size: 1.5rem;
    margin: 0 10px;
    transition: color 0.3s ease;
}

.social-links a:hover {
    color: var(--secondary-color);
}

/* Responsive Styles */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        text-align: center;
    }
    
    nav ul {
        flex-direction: column;
    }
    
    nav ul li a {
        padding: 10px 15px;
    }
    
    .profile-img {
        margin-bottom: 20px;
    }
}