:root {
    --primary-blue: #007398;
    --primary-blue-hover: #0056b3;
    --action-color: #0056b3;
    --action-color-hover: #004494;
    --text-dark: #2d2d2d;
    --text-grey: #505050;
    --text-light-grey: #737373;
    --bg-white: #ffffff;
    --bg-light: #f7f7f7;
    --border-color: #e1e1e1;
    --border-dark: #cccccc;

    --spacing-xs: 5px;
    --spacing-sm: 10px;
    --spacing-md: 15px;
    --spacing-lg: 20px;
    --spacing-xl: 30px;

    --font-family-base: Arial, Helvetica, sans-serif;
    --font-size-base: 16px;
    --line-height-base: 1.5;
}

* {
    box-sizing: border-box;
}

body {
    font-family: var(--font-family-base);
    font-size: var(--font-size-base);
    line-height: var(--line-height-base);
    color: var(--text-dark);
    background-color: var(--bg-light);
    margin: 0;
    padding: 0;
}

a {
    color: var(--primary-blue);
    text-decoration: none;
    transition: color 0.2s, text-decoration 0.2s;
}

a:hover {
    color: var(--primary-blue-hover);
    text-decoration: underline;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--text-dark);
    margin-top: 0;
    margin-bottom: var(--spacing-sm);
    font-weight: 400;
}

h1 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

h2 {
    font-size: 22px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
}

h3 {
    font-size: 18px;
    font-weight: 700;
}

p {
    margin-bottom: var(--spacing-md);
}

img {
    max-width: 100%;
    height: auto;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.main-layout {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.single-column-layout {
    max-width: 1000px;
    margin: var(--spacing-xl) auto;
}

.site-header {
    background-color: var(--bg-white);
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.top-bar {
    background-color: var(--text-dark);
    color: var(--bg-white);
    padding: var(--spacing-xs) 0;
    font-size: 13px;
}

.top-bar .container {
    display: flex;
    justify-content: flex-end;
    align-items: center;
}

.language-switcher a {
    color: #ccc;
    margin-left: var(--spacing-sm);
    text-decoration: none;
}

.language-switcher a.active {
    color: var(--bg-white);
    font-weight: bold;
}

.journal-hero {
    padding: var(--spacing-lg) 0;
    border-bottom: 1px solid var(--border-color);
}

.journal-hero .container {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

.journal-logo {
    width: 180px;
    height: auto;
}

.journal-title-block h1 {
    margin: 0;
    line-height: 1.2;
    color: var(--text-dark);
}

.journal-issn {
    color: var(--text-grey);
    font-size: 14px;
    margin-top: var(--spacing-xs);
}

.journal-metrics {
    margin-left: auto;
    display: flex;
    gap: var(--spacing-lg);
    text-align: right;
}

.metric-item {
    display: flex;
    flex-direction: column;
}

.metric-value {
    font-size: 18px;
    font-weight: bold;
    color: var(--primary-blue);
}

.metric-label {
    font-size: 12px;
    color: var(--text-grey);
}

.nav-bar {
    background-color: var(--bg-white);
    border-bottom: 1px solid var(--border-color);
}

.nav-bar ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-wrap: wrap;
}

.nav-bar li {
    margin: 0;
}

.nav-bar a {
    display: block;
    padding: var(--spacing-md) var(--spacing-lg);
    color: var(--text-dark);
    font-weight: 600;
    border-bottom: 3px solid transparent;
}

.nav-bar a:hover,
.nav-bar a.active {
    color: var(--primary-blue);
    background-color: #f0f7fa;
    border-bottom-color: var(--primary-blue);
    text-decoration: none;
}

.sidebar {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.sidebar-widget {
    background-color: var(--bg-white);
    border: 1px solid var(--border-color);
    padding: var(--spacing-md);
    border-radius: 4px;
}

.sidebar-widget h3 {
    font-size: 16px;
    text-transform: uppercase;
    color: var(--text-grey);
    margin-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: var(--spacing-xs);
}

.sidebar-widget img {
    max-height: 50px;
    width: auto;
    margin-bottom: 10px;
}

.sidebar-widget img.scimago-image {
    max-height: none;
    width: 100%;
}

.issues-tree {
    background-color: var(--bg-white);
    border: 1px solid var(--border-color);
    padding: var(--spacing-md);
    border-radius: 4px;
}

.year-group h4 {
    background-color: #f0f7fa;
    padding: 8px 12px;
    margin: 0 0 5px 0;
    border-radius: 4px;
    font-size: 15px;
    font-weight: 600;
    color: var(--text-dark);
    transition: background-color 0.2s;
}

.year-group h4:hover {
    background-color: #e1eef5;
}

.issues-list {
    list-style: none;
    padding: 0 0 0 15px;
    margin: 0 0 10px 0;
    display: none;
}

.issues-list li {
    margin: 5px 0;
}

.issues-list a {
    font-size: 14px;
    color: var(--text-grey);
    display: block;
    padding: 3px 0;
}

.issues-list a:hover {
    color: var(--primary-blue);
    text-decoration: none;
    padding-left: 5px;
    transition: padding-left 0.2s;
}

.btn {
    display: inline-block;
    padding: 10px 20px;
    border-radius: 4px;
    text-align: center;
    font-weight: 600;
    cursor: pointer;
    width: 100%;
    margin-bottom: var(--spacing-sm);
    box-sizing: border-box;
    text-decoration: none !important;
}

.btn-primary {
    background-color: var(--action-color);
    color: white !important;
    border: 1px solid var(--action-color);
}

.btn-primary:hover {
    background-color: var(--action-color-hover);
    border-color: var(--action-color-hover);
}

.btn-outline {
    background-color: transparent;
    color: var(--primary-blue) !important;
    border: 1px solid var(--primary-blue);
}

.btn-outline:hover {
    background-color: #e6f2f8;
}

.article-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.article-card {
    background-color: var(--bg-white);
    border: 1px solid var(--border-color);
    padding: var(--spacing-lg);
    border-radius: 4px;
    display: flex;
    gap: var(--spacing-lg);
    transition: box-shadow 0.2s;
}

.article-card:hover {
    box-shadow: 0 4px 8px rgba(0,0,0,0.05);
}

.article-image-container {
    flex-shrink: 0;
    width: 120px;
}

.article-image {
    width: 100%;
    height: auto;
    object-fit: cover;
    border: 1px solid var(--border-color);
}

.article-content {
    flex-grow: 1;
}

.article-type {
    font-size: 12px;
    text-transform: uppercase;
    color: var(--text-grey);
    margin-bottom: var(--spacing-xs);
}

.article-title {
    font-size: 18px;
    margin-bottom: var(--spacing-xs);
}

.article-title a {
    color: var(--primary-blue);
}

.article-authors {
    font-size: 14px;
    color: var(--text-grey);
    margin-bottom: var(--spacing-sm);
}

.article-meta {
    font-size: 13px;
    color: var(--text-light-grey);
    margin-bottom: var(--spacing-sm);
}

.article-abstract-preview {
    font-size: 14px;
    color: var(--text-dark);
    display: -webkit-box;
    -webkit-line-clamp: 3;
    line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.article-abstract-preview.expanded {
    display: block;
    -webkit-line-clamp: unset;
    line-clamp: unset;
}

.expand-btn {
    color: var(--primary-blue);
    cursor: pointer;
    font-size: 13px;
    margin-top: 5px;
    display: inline-block;
    background: none;
    border: none;
    padding: 0;
    font-family: inherit;
}

.expand-btn:hover {
    text-decoration: underline;
}

.article-actions {
    margin-top: var(--spacing-sm);
    display: flex;
    gap: var(--spacing-md);
}

.article-action-link {
    font-size: 13px;
    color: var(--primary-blue);
    display: flex;
    align-items: center;
    gap: 5px;
}

.article-header {
    margin-bottom: var(--spacing-xl);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: var(--spacing-lg);
}

.article-full-title {
    font-size: 26px;
    margin-bottom: var(--spacing-md);
    color: var(--text-dark);
}

.article-full-authors {
    font-size: 16px;
    margin-bottom: var(--spacing-sm);
}

.article-affiliations {
    font-size: 13px;
    color: var(--text-grey);
    font-style: italic;
    margin-bottom: var(--spacing-md);
}

.article-dates {
    font-size: 13px;
    color: var(--text-grey);
}

.article-section {
    margin-bottom: var(--spacing-xl);
}

.article-section h2 {
    font-size: 20px;
    border-bottom: none;
    color: var(--text-dark);
    margin-bottom: var(--spacing-sm);
}

.abstract-text {
    font-size: 16px;
    text-align: justify;
}

.keywords-list {
    margin-top: var(--spacing-sm);
    font-size: 14px;
}

.keyword {
    display: inline-block;
    background-color: #f0f0f0;
    padding: 2px 8px;
    border-radius: 3px;
    margin-right: 5px;
    margin-bottom: 5px;
    color: var(--text-grey);
}

.site-footer {
    background-color: var(--text-dark);
    color: #ccc;
    padding: var(--spacing-xl) 0;
    margin-top: var(--spacing-xl);
    font-size: 14px;
}

.site-footer a {
    color: white;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
}

.footer-col h4 {
    color: white;
    font-size: 16px;
    margin-bottom: var(--spacing-md);
}

.footer-col ul {
    list-style: none;
    padding: 0;
}

.footer-col li {
    margin-bottom: 8px;
}

.footer-bottom {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-md);
    border-top: 1px solid #444;
    text-align: center;
    font-size: 12px;
}

/* Responsive */
@media (max-width: 900px) {
    .main-layout {
        grid-template-columns: 1fr; /* Stack sidebar below content */
    }

    .journal-metrics {
        display: none; /* Hide metrics on smaller screens */
    }
}

/* Portal Navigation & Announcement Enhancements */
.nav-bar .nav-portal-btn {
    margin-left: auto;
    background: linear-gradient(135deg, #007398 0%, #0056b3 100%);
    color: #ffffff !important;
    border-radius: 4px;
    padding: 8px 16px !important;
    margin-top: 4px;
    margin-bottom: 4px;
    margin-right: 8px;
    border-bottom: none !important;
    font-weight: 700 !important;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    box-shadow: 0 2px 4px rgba(0, 115, 152, 0.25);
    transition: all 0.2s ease;
}

.nav-bar .nav-portal-btn:hover {
    background: linear-gradient(135deg, #0056b3 0%, #004494 100%) !important;
    color: #ffffff !important;
    box-shadow: 0 4px 8px rgba(0, 86, 179, 0.35);
    transform: translateY(-1px);
    text-decoration: none;
}

.portal-announcement-card {
    background: linear-gradient(135deg, #f0f7fa 0%, #e6f3f8 100%);
    border: 1px solid #bce1ee;
    border-left: 5px solid #007398;
    padding: 20px 24px;
    border-radius: 6px;
    margin-bottom: 25px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.04);
}

.announcement-badge {
    display: inline-block;
    background: #007398;
    color: #ffffff;
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    padding: 3px 8px;
    border-radius: 3px;
    margin-bottom: 10px;
}

.portal-announcement-card h3 {
    margin: 0 0 8px 0;
    color: #004494;
    font-size: 18px;
}

.portal-announcement-card p {
    margin: 0 0 16px 0;
    color: #333333;
    font-size: 15px;
    line-height: 1.6;
}

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

.btn-portal-cta {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: #007398;
    color: #fff !important;
    padding: 10px 20px;
    border-radius: 4px;
    font-weight: 600;
    font-size: 14px;
    text-decoration: none;
    box-shadow: 0 2px 4px rgba(0, 115, 152, 0.25);
    transition: all 0.2s;
}

.btn-portal-cta:hover {
    background: #0056b3;
    text-decoration: none;
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(0, 86, 179, 0.3);
}

/* ==========================================================================
   Responsive Breakpoints & Mobile Optimization
   ========================================================================== */
@media (max-width: 992px) {
    .main-layout {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    .journal-hero .container {
        flex-wrap: wrap;
    }
    .journal-metrics {
        margin-left: 0;
        width: 100%;
        justify-content: flex-start;
        margin-top: var(--spacing-sm);
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 12px;
    }
    .top-bar .container {
        justify-content: center;
    }
    .journal-hero {
        padding: var(--spacing-md) 0;
    }
    .journal-hero .container {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
    }
    .journal-logo {
        width: 120px;
        max-width: 100%;
    }
    .journal-title-block {
        width: 100%;
    }
    .journal-title-block h1 {
        font-size: 20px;
        line-height: 1.25;
        word-break: break-word;
    }
    .journal-metrics {
        display: none;
    }
    .nav-bar ul {
        flex-direction: column;
        width: 100%;
    }
    .nav-bar li {
        width: 100%;
    }
    .nav-bar a {
        padding: 10px 14px;
        border-bottom: 1px solid var(--border-color);
        width: 100%;
    }
    .nav-portal-btn {
        margin-left: 0 !important;
        margin-top: 4px;
        border-radius: 0;
        text-align: center;
    }
    .portal-announcement-card {
        padding: 16px;
    }
    .btn-portal-cta {
        display: flex;
        width: 100%;
        text-align: center;
        justify-content: center;
        box-sizing: border-box;
    }
    .article-item {
        padding: 14px;
    }
    .article-title {
        font-size: 16px;
    }
}

@media (max-width: 480px) {
    .journal-title-block h1 {
        font-size: 18px;
    }
    .btn-portal-cta {
        font-size: 13px;
        padding: 10px 14px;
    }
}