/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2c3e50;
    --secondary-color: #e67e22;
    --accent-color: #3498db;
    --text-color: #333;
    --light-bg: #f8f9fa;
    --border-color: #dee2e6;
    --success-color: #27ae60;
    --error-color: #e74c3c;
    --max-width: 1200px;
}

body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: #fff;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    margin-bottom: 1rem;
    color: var(--primary-color);
    font-weight: 500;
    line-height: 1.3;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }

p {
    margin-bottom: 1rem;
}

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

a:hover {
    color: #d35400;
    text-decoration: underline;
}

/* Header */
header {
    background: linear-gradient(135deg, var(--primary-color), #34495e);
    color: white;
    padding: 2rem 0;
    border-bottom: 3px solid var(--secondary-color);
}

.header-content {
    text-align: center;
    margin-bottom: 1.5rem;
}

.site-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.site-title a {
    color: white;
    text-decoration: none;
}

.site-title a:hover {
    color: var(--secondary-color);
    text-decoration: none;
}

.site-subtitle {
    font-size: 1rem;
    opacity: 0.9;
}

/* Navigation */
.main-nav {
    text-align: center;
}

.main-nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 2rem;
}

.main-nav a {
    color: white;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: background-color 0.3s ease;
}

.main-nav a:hover,
.main-nav a.active {
    background-color: var(--secondary-color);
    text-decoration: none;
}

/* Main Content */
main {
    min-height: 60vh;
    padding: 3rem 0;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, rgba(44, 62, 80, 0.9), rgba(52, 73, 94, 0.9)), 
                url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" preserveAspectRatio="none"><path d="M0 0 L100 100 M100 0 L0 100" stroke="rgba(255,255,255,0.1)" stroke-width="1"/></svg>');
    background-size: cover;
    color: white;
    padding: 4rem 0;
    margin-bottom: 3rem;
    border-radius: 8px;
}

.hero-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

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

.journal-description {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* Article Preview */
.article-preview {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.article-preview.featured {
    border-left: 4px solid var(--secondary-color);
}

.article-meta {
    color: #666;
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.authors {
    font-weight: 500;
}

.article-abstract {
    margin-bottom: 1.5rem;
}

.article-links {
    margin-bottom: 1rem;
}

.article-links .btn {
    margin-right: 1rem;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.5rem 1rem;
    background-color: var(--light-bg);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    text-decoration: none;
    transition: all 0.3s ease;
    cursor: pointer;
    font-size: 0.9rem;
}

.btn:hover {
    background-color: var(--border-color);
    text-decoration: none;
}

.btn-primary {
    background-color: var(--secondary-color);
    color: white;
    border-color: var(--secondary-color);
}

.btn-primary:hover {
    background-color: #d35400;
    border-color: #d35400;
}

.btn-secondary {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.btn-secondary:hover {
    background-color: #34495e;
    border-color: #34495e;
}

/* Metadata Table */
.metadata-table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 2rem;
}

.metadata-table th,
.metadata-table td {
    padding: 0.75rem;
    border-bottom: 1px solid var(--border-color);
    text-align: left;
}

.metadata-table th {
    width: 150px;
    font-weight: 500;
    color: var(--primary-color);
}

/* Keywords */
.keyword {
    display: inline-block;
    padding: 0.2rem 0.5rem;
    margin: 0.2rem;
    background-color: var(--light-bg);
    border: 1px solid var(--border-color);
    border-radius: 3px;
    font-size: 0.85rem;
    color: var(--text-color);
    text-decoration: none;
}

.keyword:hover {
    background-color: var(--secondary-color);
    color: white;
    text-decoration: none;
}

/* Full Article */
.full-article {
    max-width: 800px;
    margin: 0 auto;
}

.article-header {
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border-color);
}

.author-affiliations {
    margin: 1rem 0;
}

.author {
    margin-bottom: 0.5rem;
}

.author-name {
    font-weight: 500;
    font-size: 1.1rem;
}

.affiliation {
    display: block;
    color: #666;
    font-size: 0.9rem;
}

.orcid {
    font-size: 0.85rem;
}

.publication-info,
.doi-info {
    color: #666;
    font-size: 0.95rem;
}

.abstract {
    background-color: var(--light-bg);
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 2rem;
}

.article-section {
    margin-bottom: 2rem;
}

.article-section h2 {
    font-size: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
    margin-bottom: 1rem;
}

.section-content {
    margin-left: 1rem;
}

.section-content ul,
.section-content ol {
    margin-left: 2rem;
    margin-bottom: 1rem;
}

/* References */
.references {
    margin: 2rem 0;
    padding-top: 1rem;
    border-top: 2px solid var(--border-color);
}

.references-list {
    list-style-type: decimal;
    margin-left: 2rem;
    font-size: 0.95rem;
}

.references-list li {
    margin-bottom: 0.5rem;
}

/* Citation Tools */
.citation-tools {
    background-color: var(--light-bg);
    padding: 1.5rem;
    border-radius: 8px;
    margin: 2rem 0;
}

.citation-formats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.citation-format {
    background: white;
    padding: 1rem;
    border-radius: 4px;
    border: 1px solid var(--border-color);
    position: relative;
}

.citation-format h4 {
    margin-bottom: 0.5rem;
    font-size: 1rem;
}

.citation-format p {
    font-size: 0.9rem;
    font-family: monospace;
    background: var(--light-bg);
    padding: 0.5rem;
    border-radius: 3px;
    margin-bottom: 2rem;
}

.citation-format button {
    position: absolute;
    bottom: 1rem;
    right: 1rem;
    padding: 0.25rem 0.5rem;
    font-size: 0.8rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 3px;
    cursor: pointer;
}

.citation-format button:hover {
    background: var(--secondary-color);
}

/* Article Actions */
.article-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin: 2rem 0;
}

/* Author Profile */
.author-profile {
    max-width: 800px;
    margin: 0 auto;
}

.author-header {
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border-color);
}

.author-affiliation {
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 0.5rem;
}

.education-list,
.publications-list,
.research-interests {
    list-style-type: none;
    margin-bottom: 2rem;
}

.education-list li,
.publication-item {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border-color);
}

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

.publication-meta {
    color: #666;
    font-size: 0.9rem;
}

.social-links {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.social-links a {
    padding: 0.5rem 1rem;
    background: var(--light-bg);
    border-radius: 4px;
    border: 1px solid var(--border-color);
}

/* Search Page */
.search-page {
    max-width: 800px;
    margin: 0 auto;
}

.search-form {
    margin-bottom: 2rem;
}

.search-box {
    display: flex;
    gap: 1rem;
}

.search-box input {
    flex: 1;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
}

.search-box input:focus {
    outline: none;
    border-color: var(--secondary-color);
}

.result-count {
    color: #666;
    margin-bottom: 1rem;
}

.search-result-item {
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: 1rem;
    background: white;
}

.result-meta {
    color: #666;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.result-abstract {
    margin-bottom: 0.5rem;
}

.result-keywords {
    font-size: 0.9rem;
}

.no-results {
    text-align: center;
    padding: 3rem;
    color: #666;
}

.keyword-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1rem;
}

.keyword-link {
    padding: 0.25rem 0.75rem;
    background: var(--light-bg);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    font-size: 0.9rem;
    color: var(--text-color);
    text-decoration: none;
}

.keyword-link:hover {
    background: var(--secondary-color);
    color: white;
    text-decoration: none;
}

/* Footer */
footer {
    background-color: var(--primary-color);
    color: white;
    padding: 3rem 0 1rem;
    margin-top: 3rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    color: white;
    font-size: 1.2rem;
    margin-bottom: 1rem;
    border-bottom: 2px solid var(--secondary-color);
    padding-bottom: 0.5rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: #ddd;
    text-decoration: none;
}

.footer-section a:hover {
    color: var(--secondary-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255,255,255,0.1);
    font-size: 0.9rem;
    opacity: 0.8;
}

.issn-statement {
    margin-top: 0.5rem;
    font-style: italic;
}

/* Responsive Design */
@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; }
    h3 { font-size: 1.25rem; }
    
    .main-nav ul {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .main-nav a {
        display: block;
    }
    
    .hero h2 {
        font-size: 1.8rem;
    }
    
    .citation-formats {
        grid-template-columns: 1fr;
    }
    
    .article-actions {
        flex-direction: column;
    }
    
    .article-actions .btn {
        text-align: center;
    }
    
    .search-box {
        flex-direction: column;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

/* Print Styles */
@media print {
    header, footer, .article-actions, .citation-tools {
        display: none;
    }
    
    body {
        font-size: 12pt;
    }
    
    .full-article {
        max-width: 100%;
    }
    
    a {
        color: black;
        text-decoration: none;
    }
}