/* Main Stylesheet for Chi Zhang's Personal Website */

/* Base Styles */
body {
    font-family: 'Lato', Verdana, Helvetica, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: #444;
    margin: 0;
    padding: 0;
    background-color: #f9f9f9;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Lato', Verdana, Helvetica, sans-serif;
    margin-top: 0;
    color: #2980b9;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #3498db;
}

h2 {
    font-size: 2rem;
    margin-bottom: 0.75rem;
    border-bottom: 1px solid #e0e0e0;
    padding-bottom: 0.5rem;
}

h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: #2980b9;
}

p {
    margin-bottom: 1rem;
}

strong {
    font-weight: 700;
    color: #2c3e50;
}

/* Links */
a {
    color: #3498db;
    text-decoration: none;
    transition: color 0.3s ease;
}

a:focus, a:hover {
    color: #f39c12;
    text-decoration: none;
}

/* Custom Classes */
.heading {
    font-family: 'Lato', Verdana, Helvetica, sans-serif;
    font-size: 1.2rem;
    font-weight: 700;
}

.conference {
    font-family: 'Lato', Verdana, Helvetica, sans-serif;
    color: #000000;
    font-size: 1rem;
    font-weight: 700;
    text-decoration: none;
}

/* Layout */
.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
    background-color: #fff;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.05);
    border-radius: 8px;
}

.header {
    text-align: center;
    padding: 2.5rem 0;
    background: linear-gradient(to right, #3498db, #2980b9);
    color: white;
    border-radius: 8px 8px 0 0;
    margin-bottom: 2rem;
}

.header h1 {
    color: white;
    margin: 0;
}

.profile-section {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-start;
    margin-bottom: 2rem;
    padding: 0 1.5rem;
}

.profile-info {
    flex: 2;
    padding-right: 2rem;
}

.profile-image {
    flex: 1;
    text-align: center;
}

.profile-image img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.section {
    margin-bottom: 3rem;
    padding: 1.5rem;
    background-color: #fff;
    border-radius: 8px;
}

.publication {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid #e0e0e0;
    transition: transform 0.2s ease;
}

.publication:hover {
    transform: translateY(-3px);
}

.publication:last-child {
    border-bottom: none;
}

.publication-title {
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: #2980b9;
}

.publication-authors {
    margin-bottom: 0.5rem;
}

.publication-venue {
    font-style: italic;
    margin-bottom: 0.5rem;
    color: #555;
}

.contact-links {
    text-align: center;
    margin: 2rem 0;
    padding: 1rem;
    background-color: #f5f5f5;
    border-radius: 8px;
}

.contact-links a {
    margin: 0 10px;
    font-weight: 600;
}

.footer {
    text-align: center;
    padding: 2rem 0;
    margin-top: 2rem;
    font-size: 0.9rem;
    color: #777;
    background-color: #f5f5f5;
    border-radius: 0 0 8px 8px;
}

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 20px;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
    z-index: 999;
}

.back-to-top:hover {
    background-color: #f39c12;
    transform: translateY(-3px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
}

.back-to-top.visible {
    display: flex;
}

/* Research Area Styling */
.research-area {
    padding: 1.5rem;
    margin-bottom: 2rem;
    background-color: #f8f9fa;
    border-radius: 8px;
    border-left: 4px solid #3498db;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.research-area:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.research-area h3 {
    color: #2980b9;
    margin-top: 0;
}

.research-area ul {
    padding-left: 1.5rem;
}

.research-area li {
    margin-bottom: 0.5rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .profile-section {
        flex-direction: column-reverse;
    }
    
    .profile-info {
        padding-right: 0;
        margin-top: 1rem;
    }
    
    .profile-image {
        margin-bottom: 1rem;
    }
    
    .container {
        padding: 0 15px;
    }
    
    .header {
        padding: 1.5rem 0;
    }
}