/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
}

/* Container */
.container {
    max-width: 1800px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Layout Grid */
.layout-grid {
    display: grid;
    grid-template-columns: 400px 1fr;
    gap: 3rem;
    margin-top: 60px;
    position: relative;
}

/* Left Column - Profile */
.left-column {
    background-color: #fff;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    height: fit-content;
    position: sticky;
    top: 80px;
    width: 400px;
    max-height: calc(100vh - 100px);
    overflow-y: auto;
}

.profile {
    text-align: left;
}

.profile-image {
    margin-bottom: 1.5rem;
    text-align: center;
}

.image-placeholder {
    width: 200px;
    height: 200px;
    background-color: #f0f0f0;
    border-radius: 50%;
    overflow: hidden;
    margin: 0 auto;
}

.image-placeholder i {
    font-size: 5rem;
    color: #ccc;
}

.description {
    margin-top: 1.5rem;
    text-align: left;
}

/* Social Links */
.social-links {
    margin-top: 2rem;
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.social-link {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: #333;
    padding: 0.5rem;
    border-radius: 4px;
    transition: all 0.3s ease;
}

.social-link i {
    width: 24px;
    margin-right: 0.8rem;
    font-size: 1.2rem;
}

.social-link:hover {
    background-color: #f8f9fa;
    color: #007bff;
    transform: translateX(5px);
}

/* Right Column - Publications */
.right-column {
    padding: 0 2rem;
}

/* Header and Navigation */
header {
    background-color: #fff;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

nav ul {
    display: flex;
    justify-content: center;
    list-style: none;
    padding: 1rem 0;
}

nav ul li {
    margin: 0 2rem;
}

nav ul li a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    font-size: 1.2rem;
    transition: color 0.3s ease;
}

nav ul li a:hover {
    color: #007bff;
}

/* Sections */
.section {
    padding: 2rem 0;
    min-height: 100vh;
}

/* Typography */
h1 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: #2c3e50;
}

h2 {
    font-size: 1.8rem;
    margin-bottom: 2rem;
    color: #34495e;
    text-align: center;
}

h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #2c3e50;
}

/* Publications */
.publications-list {
    display: grid;
    gap: 2rem;
    width: 100%;
}

.publication {
    background-color: #fff;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    transition: transform 0.2s ease;
}

.publication:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}

.publication .authors {
    color: #666;
    margin-bottom: 0.5rem;
}

.publication .venue {
    color: #007bff;
    font-weight: 500;
    margin-bottom: 1rem;
}

.publication .description {
    color: #666;
    margin: 0.5rem 0 1rem;
    font-style: italic;
    line-height: 1.4;
}

/* Buttons and Links */
.btn {
    display: inline-flex;
    align-items: center;
    padding: 0.5rem 1rem;
    background-color: #007bff;
    color: #fff;
    text-decoration: none;
    border-radius: 4px;
    margin-right: 1rem;
    transition: background-color 0.3s ease;
}

.btn i {
    margin-right: 0.5rem;
}

.btn:hover {
    background-color: #0056b3;
}

/* Footer */
footer {
    background-color: #2c3e50;
    color: #fff;
    padding: 2rem 0;
    text-align: center;
    margin-top: 2rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .layout-grid {
        grid-template-columns: 1fr;
    }

    .left-column {
        position: static;
        margin-bottom: 2rem;
        width: 100%;
        max-height: none;
        overflow-y: visible;
    }

    .social-links {
        flex-direction: row;
        flex-wrap: wrap;
        justify-content: center;
    }

    .social-link {
        padding: 0.5rem 1rem;
    }

    nav ul {
        flex-direction: row;
        align-items: center;
    }

    nav ul li {
        margin: 0 1rem;
    }

    .section {
        padding: 1rem 0;
    }

    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.6rem;
    }

    .right-column {
        padding: 0;
    }

    .publications-list {
        max-width: 100%;
    }
}

.profile-photo {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    margin: 0 auto;
    display: block;
    border: 3px solid #fff;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.loading, .error, .no-papers {
    text-align: center;
    padding: 2rem;
    color: #666;
    font-style: italic;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.error {
    color: #dc3545;
}

.no-papers {
    color: #6c757d;
}

/* Book(s) Section */
.books-section {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 2px solid #f0f0f0;
    max-width: 1000px;
    margin-left: auto;
    margin-right: auto;
}

.books-section h2 {
    text-align: center;
    margin-bottom: 2rem;
}

.book-entry {
    display: flex;
    align-items: flex-start;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.08);
    padding: 2rem;
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.book-cover img {
    width: 120px;
    height: 170px;
    object-fit: cover;
    border-radius: 6px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.10);
    background: #f8f8f8;
}

.book-info {
    flex: 1;
}

.book-info h3 {
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
    color: #2c3e50;
}

.book-authors {
    color: #666;
    margin-bottom: 0.5rem;
    font-size: 1rem;
}

.book-description {
    margin-bottom: 1rem;
    color: #444;
    font-size: 0.95rem;
    line-height: 1.3;
    max-width: 90%;
}

.book-meta {
    font-size: 0.95rem;
    color: #555;
    margin-bottom: 1rem;
}

.book-amazon-link {
    background: #ff9900;
    color: #fff;
    font-weight: 500;
    border: none;
    transition: background 0.2s;
}

.book-amazon-link:hover {
    background: #e68a00;
    color: #fff;
}

@media (max-width: 768px) {
    .books-section, .book-entry {
        max-width: 100%;
    }
    .book-entry {
        flex-direction: column;
        align-items: center;
        padding: 1rem;
    }
    .book-cover img {
        width: 100px;
        height: 140px;
    }
}