/* Prefab House Theme - Modular Prefabricated Container House & Structural Engineering Styles */

:root {
    --bg-page: #f8fafc;
    --bg-surface: #ffffff;
    --bg-surface-elevated: #f1f5f9;
    --border-color: #e2e8f0;
    --border-accent: #0284c7;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --accent-blue: #0284c7;
    --accent-blue-hover: #0369a1;
    --accent-steel: #334155;
    --accent-light: #e0f2fe;
    --card-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
    --card-shadow-hover: 0 10px 15px -3px rgba(2, 132, 199, 0.12), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
    --container-width: 1140px;
    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 10px;
}

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    background-color: var(--bg-page);
    color: var(--text-primary);
    font-family: var(--font-sans);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

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

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

.site-main-container {
    flex: 1 0 auto;
}

.content-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 2.5rem 1.5rem;
}

/* Header */
.site-header {
    background-color: var(--bg-surface);
    border-bottom: 2px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 50;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.05);
}

.header-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 1rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
}

.header-brand {
    display: flex;
    align-items: baseline;
    gap: 1rem;
    flex-wrap: wrap;
}

.brand-link {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    color: var(--accent-steel);
    font-weight: 700;
    font-size: 1.35rem;
    letter-spacing: -0.02em;
}

.brand-icon {
    color: var(--accent-blue);
    display: flex;
    align-items: center;
}

.brand-name {
    color: var(--text-primary);
}

.brand-tagline {
    color: var(--text-secondary);
    font-size: 0.85rem;
    border-left: 2px solid var(--border-color);
    padding-left: 0.75rem;
}

.site-nav {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.95rem;
    padding: 0.35rem 0.2rem;
    position: relative;
}

.nav-link:hover {
    color: var(--accent-blue);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--accent-blue);
    transition: width 0.2s ease;
}

.nav-link:hover::after {
    width: 100%;
}

/* Banner */
.banner-section {
    position: relative;
    width: 100%;
    height: 380px;
    background-color: var(--accent-steel);
    overflow: hidden;
    border-bottom: 1px solid var(--border-color);
}

.banner-media {
    position: relative;
    width: 100%;
    height: 100%;
}

.banner-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
    filter: brightness(0.7) contrast(1.05);
}

.banner-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, rgba(2, 132, 199, 0.2) 0%, rgba(15, 23, 42, 0.75) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 2rem 1.5rem;
}

.banner-content {
    max-width: 800px;
}

.banner-title {
    color: #ffffff;
    font-size: 2.75rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 0.75rem;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.6);
    letter-spacing: -0.01em;
}

.banner-desc {
    color: #f1f5f9;
    font-size: 1.15rem;
    font-weight: 400;
    text-shadow: 0 1px 4px rgba(0, 0, 0, 0.6);
}

/* Prefab Cards */
.prefab-card, .card-item {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--card-shadow);
    transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.card-list {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.75rem;
}

.card-item {
    position: relative;
    overflow: hidden;
    border-top: 3px solid var(--border-color);
}

.card-item:hover {
    transform: translateY(-2px);
    border-top-color: var(--accent-blue);
    box-shadow: var(--card-shadow-hover);
}

.article-card {
    padding: 1.75rem;
    background: transparent;
    border: none;
    box-shadow: none;
}

.card-header {
    margin-bottom: 1rem;
}

.card-meta, .article-meta {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.75rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.meta-date {
    display: flex;
    align-items: center;
    gap: 0.35rem;
}

.meta-icon {
    stroke: var(--text-muted);
}

.badge {
    display: inline-block;
    padding: 0.2rem 0.55rem;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.badge-category {
    background-color: var(--accent-light);
    color: var(--accent-blue-hover);
    border: 1px solid rgba(2, 132, 199, 0.25);
}

.badge-category:hover {
    background-color: #bae6fd;
    color: #0284c7;
}

.badge-tag {
    background-color: var(--bg-surface-elevated);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
}

.badge-tag:hover {
    color: var(--accent-blue);
    border-color: var(--accent-blue);
}

.card-title {
    font-size: 1.45rem;
    font-weight: 700;
    line-height: 1.3;
}

.card-title a {
    color: var(--text-primary);
}

.card-title a:hover {
    color: var(--accent-blue);
}

.card-excerpt {
    color: var(--text-secondary);
    font-size: 0.975rem;
    line-height: 1.65;
    margin-bottom: 1.25rem;
}

.card-footer {
    display: flex;
    justify-content: flex-end;
}

.read-more-link {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--accent-blue);
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
}

.read-more-link:hover {
    color: var(--accent-blue-hover);
    gap: 0.45rem;
}

/* Pagination */
.pagination-nav {
    margin-top: 2.5rem;
    display: flex;
    justify-content: center;
}

.pagination-inner {
    display: flex;
    align-items: center;
    gap: 1rem;
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    box-shadow: var(--card-shadow);
}

.pagination-btn {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
    padding: 0.35rem 0.75rem;
    border-radius: var(--radius-sm);
    background-color: var(--bg-surface-elevated);
    border: 1px solid var(--border-color);
}

.pagination-btn:hover {
    color: var(--accent-blue);
    border-color: var(--accent-blue);
}

.pagination-info {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* Taxonomy / List Page */
.list-section {
    max-width: var(--container-width);
}

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

.list-title {
    font-size: 2rem;
    font-weight: 800;
    color: var(--text-primary);
}

.term-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.term-chip {
    display: inline-flex;
    align-items: center;
    gap: 0.65rem;
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    padding: 0.65rem 1.25rem;
    border-radius: var(--radius-md);
    box-shadow: var(--card-shadow);
    transition: all 0.2s ease;
}

.term-chip:hover {
    border-color: var(--accent-blue);
    transform: translateY(-2px);
    box-shadow: var(--card-shadow-hover);
}

.term-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.term-chip:hover .term-title {
    color: var(--accent-blue);
}

.term-count {
    background-color: var(--accent-light);
    color: var(--accent-blue-hover);
    font-size: 0.8rem;
    font-weight: 700;
    padding: 0.15rem 0.5rem;
    border-radius: 9999px;
}

/* Single Article */
.single-article {
    padding: 2.5rem;
}

.article-header {
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1.5rem;
    margin-bottom: 2rem;
}

.article-title {
    font-size: 2.25rem;
    font-weight: 800;
    line-height: 1.25;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

/* TOC */
.article-toc {
    background-color: var(--bg-surface-elevated);
    border: 1px solid var(--border-color);
    border-left: 4px solid var(--accent-blue);
    border-radius: var(--radius-sm);
    padding: 1.25rem 1.5rem;
    margin-bottom: 2rem;
}

.toc-title {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text-primary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.75rem;
}

.article-toc ul {
    list-style: none;
    padding-left: 1rem;
}

.article-toc > ul {
    padding-left: 0;
}

.article-toc li {
    margin-bottom: 0.35rem;
    font-size: 0.9rem;
}

.article-toc a {
    color: var(--text-secondary);
}

.article-toc a:hover {
    color: var(--accent-blue);
}

/* Markdown Content */
.markdown-body {
    color: #334155;
    font-size: 1.05rem;
    line-height: 1.8;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4,
.markdown-body h5,
.markdown-body h6 {
    color: var(--text-primary);
    font-weight: 700;
    margin-top: 2rem;
    margin-bottom: 1rem;
    line-height: 1.3;
}

.markdown-body h1 { font-size: 1.85rem; border-bottom: 1px solid var(--border-color); padding-bottom: 0.5rem; }
.markdown-body h2 { font-size: 1.5rem; border-bottom: 1px solid var(--border-color); padding-bottom: 0.4rem; }
.markdown-body h3 { font-size: 1.25rem; }

.markdown-body p,
.markdown-body ul,
.markdown-body ol,
.markdown-body blockquote,
.markdown-body table {
    margin-bottom: 1.5rem;
}

.markdown-body ul,
.markdown-body ol {
    padding-left: 1.75rem;
}

.markdown-body li {
    margin-bottom: 0.35rem;
}

.markdown-body blockquote {
    border-left: 4px solid var(--accent-blue);
    background-color: var(--bg-surface-elevated);
    padding: 1rem 1.25rem;
    color: #475569;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.markdown-body code {
    background-color: var(--bg-surface-elevated);
    color: var(--accent-blue-hover);
    padding: 0.2rem 0.4rem;
    border-radius: var(--radius-sm);
    font-family: var(--font-mono);
    font-size: 0.9em;
    border: 1px solid var(--border-color);
}

.markdown-body pre {
    background-color: #0f172a;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.25rem;
    overflow-x: auto;
    margin-bottom: 1.5rem;
}

.markdown-body pre code {
    background: transparent;
    padding: 0;
    border: none;
    color: #f8fafc;
}

.markdown-body img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    margin: 1rem 0;
}

.markdown-body table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1.5rem;
}

.markdown-body th,
.markdown-body td {
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
}

.markdown-body th {
    background-color: var(--bg-surface-elevated);
    color: var(--text-primary);
    font-weight: 600;
}

/* Article Footer */
.article-footer {
    border-top: 1px solid var(--border-color);
    padding-top: 1.5rem;
    margin-top: 2.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.taxonomy-row {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.taxonomy-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
}

/* Article Navigation */
.article-nav {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-top: 2rem;
    border-top: 1px solid var(--border-color);
    padding-top: 1.5rem;
}

.nav-prev, .nav-next {
    display: flex;
    flex-direction: column;
    padding: 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background-color: var(--bg-surface-elevated);
    transition: all 0.2s ease;
}

.nav-prev:hover, .nav-next:hover {
    border-color: var(--accent-blue);
    background-color: var(--bg-surface);
}

.nav-prev span, .nav-next span {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--accent-blue);
    margin-bottom: 0.35rem;
}

.nav-prev strong, .nav-next strong {
    font-size: 0.95rem;
    color: var(--text-primary);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.nav-next {
    text-align: right;
}

/* Archives Timeline */
.archives-wrapper {
    padding: 2.5rem;
}

.archives-header {
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 1rem;
    margin-bottom: 2.5rem;
}

.archives-title {
    font-size: 2rem;
    font-weight: 800;
    color: var(--text-primary);
}

.archive-year-group {
    margin-bottom: 2.5rem;
    position: relative;
    padding-left: 2rem;
    border-left: 2px solid var(--border-color);
}

.archive-year-group::before {
    content: '';
    position: absolute;
    left: -7px;
    top: 6px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: var(--accent-blue);
    box-shadow: 0 0 6px rgba(2, 132, 199, 0.4);
}

.year-header {
    display: flex;
    align-items: baseline;
    gap: 1rem;
    margin-bottom: 1.25rem;
}

.year-title {
    font-size: 1.65rem;
    font-weight: 700;
    color: var(--text-primary);
}

.year-badge {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.archive-items {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.85rem;
}

.archive-item {
    display: flex;
    align-items: baseline;
    gap: 1.25rem;
    font-size: 1rem;
}

.archive-date {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--accent-blue);
    flex-shrink: 0;
}

.archive-link {
    color: var(--text-primary);
}

.archive-link:hover {
    color: var(--accent-blue);
}

/* Back to top */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background-color: var(--accent-blue);
    color: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
    z-index: 40;
    transition: transform 0.2s ease, background-color 0.2s ease;
}

.back-to-top:hover {
    background-color: var(--accent-blue-hover);
    color: #ffffff;
    transform: translateY(-3px);
}

/* Footer */
.site-footer {
    background-color: var(--bg-surface);
    border-top: 1px solid var(--border-color);
    padding: 2rem 1.5rem;
    margin-top: 3rem;
}

.footer-container {
    max-width: var(--container-width);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.footer-top a {
    color: var(--text-secondary);
}

.footer-top a:hover {
    color: var(--accent-blue);
}

.empty-state {
    color: var(--text-muted);
    font-style: italic;
    padding: 2rem 0;
    text-align: center;
}

/* Responsive */
@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        align-items: flex-start;
    }

    .banner-title {
        font-size: 2rem;
    }

    .banner-section {
        height: 280px;
    }

    .single-article, .archives-wrapper {
        padding: 1.5rem;
    }

    .article-nav {
        grid-template-columns: 1fr;
    }

    .archive-item {
        flex-direction: column;
        gap: 0.25rem;
    }
}