/* ============================================
   ZHL BLOG STYLES
   Extends the main design system for blog content
   ============================================ */

/* ============================================
   LAYOUT
   ============================================ */

.container-narrow {
    max-width: 720px;
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

/* ============================================
   ARTICLE HEADER
   ============================================ */

.article-header {
    padding: calc(80px + var(--space-3xl)) 0 var(--space-2xl);
    border-bottom: 1px solid var(--border-light);
}

.article-meta {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-mono);
    font-size: 0.8125rem;
    color: var(--text-tertiary);
    margin-bottom: var(--space-lg);
    flex-wrap: wrap;
}

.article-category {
    color: var(--text-primary);
    font-weight: 500;
    transition: color var(--duration-fast);
}

.article-category:hover {
    color: var(--text-secondary);
}

.meta-separator {
    color: var(--gray-300);
}

.reading-time {
    color: var(--text-tertiary);
}

.article-title {
    font-family: var(--font-display);
    font-size: clamp(2.25rem, 5vw, 3.5rem);
    font-weight: 400;
    line-height: 1.1;
    color: var(--text-primary);
    margin-bottom: var(--space-md);
    max-width: 90%;
}

.article-subtitle {
    font-size: clamp(1.125rem, 2vw, 1.375rem);
    line-height: 1.5;
    color: var(--text-secondary);
}

.article-author {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.author-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    object-fit: cover;
    background: var(--gray-100);
}

.author-info {
    display: flex;
    flex-direction: column;
    gap: 0.125rem;
}

.author-name {
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

.author-name strong {
    color: var(--text-primary);
    font-weight: 600;
}

.author-role {
    font-size: 0.8125rem;
    color: var(--text-tertiary);
}

/* ============================================
   ARTICLE CONTENT - TYPOGRAPHY
   ============================================ */

.article-content {
    padding: var(--space-2xl) 0;
}

.article-content p {
    font-size: 1.0625rem;
    line-height: 1.75;
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
}

.article-content p:last-child {
    margin-bottom: 0;
}

.article-content .lead {
    font-size: 1.25rem;
    line-height: 1.7;
    color: var(--text-primary);
    margin-bottom: var(--space-lg);
}

.article-content strong {
    color: var(--text-primary);
    font-weight: 600;
}

.article-content em {
    font-style: italic;
}

/* Headings */
.article-content h2 {
    font-family: var(--font-display);
    font-size: 1.75rem;
    font-weight: 400;
    line-height: 1.2;
    color: var(--text-primary);
    scroll-margin-top: 100px;
}

.article-content h3 {
    font-family: var(--font-body);
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-top: var(--space-lg);
    margin-bottom: var(--space-sm);
}

/* Links */
.article-content a:not(.btn):not(.tag):not(.share-btn) {
    color: var(--text-primary);
    text-decoration: underline;
    text-underline-offset: 2px;
    transition: color var(--duration-fast);
}

.article-content a:not(.btn):not(.tag):not(.share-btn):hover {
    color: var(--text-secondary);
}

/* Lists */

.article-content ul {
    list-style: none;
}

.article-content ul li {
    position: relative;
    padding-left: 1rem;
    margin-bottom: 0.5rem;
    font-size: 1.0625rem;
    line-height: 1.7;
    color: var(--text-secondary);
}

.article-content ul li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.7em;
    width: 5px;
    height: 5px;
    background: var(--gray-400);
    border-radius: 50%;
}

.article-content ol {
    list-style: none;
    counter-reset: ol-counter;
}

.article-content ol li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.75rem;
    font-size: 1.0625rem;
    line-height: 1.7;
    color: var(--text-secondary);
    counter-increment: ol-counter;
}

.article-content ol li::before {
    content: counter(ol-counter) ".";
    position: absolute;
    left: 0;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* Blockquote */
.article-content blockquote {
    margin: var(--space-xl) 0;
    padding: var(--space-lg) var(--space-xl);
    border-left: 3px solid var(--gray-900);
    background: var(--bg-secondary);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.article-content blockquote p {
    font-family: var(--font-display);
    font-size: 1.375rem;
    font-style: italic;
    line-height: 1.5;
    color: var(--text-primary);
    margin: 0;
}

/* Code */
.article-content code {
    font-family: var(--font-mono);
    font-size: 0.875em;
    background: var(--bg-secondary);
    padding: 0.2em 0.4em;
    border-radius: var(--radius-sm);
    color: var(--text-primary);
}

.article-content pre {
    margin: var(--space-lg) 0;
    padding: var(--space-lg);
    background: var(--gray-900);
    border-radius: var(--radius-lg);
    overflow-x: auto;
}

.article-content pre code {
    background: none;
    padding: 0;
    color: var(--gray-100);
    font-size: 0.875rem;
    line-height: 1.6;
}

/* ============================================
   TABLE OF CONTENTS
   ============================================ */

.toc {
    margin: var(--space-xl) 0;
    padding: var(--space-lg);
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
}

.toc-title {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-tertiary);
    margin-bottom: var(--space-sm);
}

.toc-list {
    list-style: none;
    counter-reset: toc-counter;
    padding: 0;
    margin: 0;
}

.toc-list li {
    counter-increment: toc-counter;
    margin-bottom: 0.5rem;
}

.toc-list li:last-child {
    margin-bottom: 0;
}

.toc-list a {
    display: flex;
    align-items: baseline;
    gap: 0.75rem;
    font-size: 0.9375rem;
    color: var(--text-secondary);
    text-decoration: none;
    transition: color var(--duration-fast);
}

.toc-list a:hover {
    color: var(--text-primary);
}

/* ============================================
   CALLOUT BOXES
   ============================================ */

.callout {
    margin: var(--space-lg) 0;
    padding: var(--space-lg);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-light);
}

.callout-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: var(--space-sm);
}

.callout-icon {
    font-size: 1rem;
}

.callout-label {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.callout p {
    font-size: 0.9375rem !important;
    line-height: 1.65 !important;
    margin-bottom: var(--space-sm) !important;
}

.callout p:last-child {
    margin-bottom: 0 !important;
}

.callout-result {
    padding-top: var(--space-sm);
    border-top: 1px solid var(--border-light);
    margin-top: var(--space-sm) !important;
}

/* Callout Variants */
.callout-example {
    background: var(--bg-secondary);
}

.callout-example .callout-label {
    color: var(--text-secondary);
}

.callout-tip {
    background: #fefce8;
    border-color: #fef08a;
}

.callout-tip .callout-label {
    color: #a16207;
}

.callout-tip .callout-result {
    border-top-color: #fef08a;
}

.callout-warning {
    background: #fef2f2;
    border-color: #fecaca;
}

.callout-warning .callout-label {
    color: #dc2626;
}

/* ============================================
   STAT HIGHLIGHT
   ============================================ */

.stat-highlight {
    text-align: center;
    margin: var(--space-xl) 0;
    padding: var(--space-xl);
    background: var(--gray-900);
    border-radius: var(--radius-xl);
}

.stat-highlight .stat-value {
    font-family: var(--font-display);
    font-size: 3.5rem;
    font-weight: 400;
    color: var(--white);
    line-height: 1;
    margin-bottom: var(--space-xs);
}

.stat-highlight .stat-label {
    font-size: 1rem;
    font-weight: 500;
    color: var(--gray-300);
    margin-bottom: var(--space-xs);
}

.stat-highlight .stat-context {
    font-size: 0.875rem;
    color: var(--gray-500);
}

/* ============================================
   CHECKLIST BOX
   ============================================ */

.checklist-box {
    margin: var(--space-xl) 0;
    padding: var(--space-xl);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
}

.checklist-title {
    font-family: var(--font-body);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-lg);
}

.checklist {
    list-style: none;
    padding: 0;
    margin: 0 0 var(--space-md) 0;
}

.checklist li {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-light);
    font-size: 0.9375rem;
    line-height: 1.5;
    color: var(--text-secondary);
}

.checklist li:last-child {
    border-bottom: none;
}

.checkbox {
    flex-shrink: 0;
    width: 20px;
    height: 20px;
    border: 2px solid var(--gray-300);
    border-radius: var(--radius-sm);
    margin-top: 0.125rem;
}

.article-content ul li::before {
    display: none;
}

.checklist-footer {
    font-size: 0.875rem;
    color: var(--text-tertiary);
    font-style: italic;
    margin: 0;
}

/* ============================================
   ARTICLE CTA
   ============================================ */

.article-cta {
    margin: var(--space-2xl) 0;
    padding: var(--space-xl);
    background: linear-gradient(135deg, var(--gray-900) 0%, var(--gray-800) 100%);
    border-radius: var(--radius-xl);
    text-align: center;
}

.article-cta h3 {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 400;
    color: var(--white);
    margin-bottom: var(--space-sm);
    margin-top: 0;
}

.article-cta p {
    font-size: 1rem !important;
    color: var(--gray-400) !important;
    margin-bottom: var(--space-lg) !important;
    margin-left: auto;
    margin-right: auto;
}

.article-cta .btn {
    background: var(--white);
    color: var(--gray-900);
}

.article-cta .btn:hover {
    background: var(--gray-100);
    transform: translateY(-2px);
}

/* ============================================
   ARTICLE FOOTER
   ============================================ */

.article-footer {
    padding: var(--space-xl) 0;
    border-top: 1px solid var(--border-light);
    background: var(--bg-secondary);
}

/* Tags */
.article-tags {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: var(--space-lg);
}

.tags-label {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--text-tertiary);
    margin-right: 0.25rem;
}

.tag {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    padding: 0.375rem 0.75rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-full);
    transition: all var(--duration-fast);
}

.tag:hover {
    background: var(--gray-900);
    color: var(--white);
    border-color: var(--gray-900);
}

/* Share */
.article-share {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    border-bottom: 1px solid var(--border-light);
}

.share-label {
    font-size: 0.875rem;
    color: var(--text-tertiary);
}

.share-buttons {
    display: flex;
    gap: 0.5rem;
}

.share-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    transition: all var(--duration-fast);
}

.share-btn:hover {
    background: var(--gray-900);
    border-color: var(--gray-900);
    color: var(--white);
}

/* Author Bio */
.author-bio {
    display: flex;
    gap: var(--space-md);
    align-items: flex-start;
}

.author-bio-avatar {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    object-fit: cover;
    background: var(--gray-200);
    flex-shrink: 0;
}

.author-bio-content {
    flex: 1;
}

.author-bio-name {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.author-bio-desc {
    font-size: 0.9375rem;
    line-height: 1.6;
    color: var(--text-secondary);
    margin-bottom: var(--space-sm);
}

.author-bio-link {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
    text-decoration: none;
    transition: color var(--duration-fast);
}

.author-bio-link:hover {
    color: var(--text-secondary);
}

/* ============================================
   RELATED ARTICLES
   ============================================ */

.related-articles {
    padding: var(--space-3xl) 0;
    background: var(--bg-primary);
}

.related-title {
    font-family: var(--font-display);
    font-size: 1.75rem;
    font-weight: 400;
    color: var(--text-primary);
    margin-bottom: var(--space-xl);
}

.related-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.related-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    transition: all var(--duration-normal) var(--ease-out);
}

.related-card:hover {
    border-color: var(--border-color);
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.related-card-link {
    display: block;
    padding: var(--space-lg);
    text-decoration: none;
}

.related-card-meta {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-sm);
}

.related-category {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--text-primary);
}

.related-date {
    font-size: 0.8125rem;
    color: var(--text-tertiary);
}

.related-card-title {
    font-family: var(--font-body);
    font-size: 1.125rem;
    font-weight: 600;
    line-height: 1.35;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
    transition: color var(--duration-fast);
}

.related-card:hover .related-card-title {
    color: var(--text-secondary);
}

.related-card-excerpt {
    font-size: 0.9375rem;
    line-height: 1.6;
    color: var(--text-secondary);
    margin: 0;
}

/* ============================================
   NEWSLETTER SECTION
   ============================================ */

.newsletter-section {
    padding: var(--space-2xl) 0;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-light);
}

.newsletter-box {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-2xl);
    align-items: center;
    padding: var(--space-xl);
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
}

.newsletter-content .section-label {
    margin-bottom: var(--space-sm);
}

.newsletter-title {
    font-family: var(--font-display);
    font-size: 1.75rem;
    font-weight: 400;
    line-height: 1.2;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
}

.newsletter-desc {
    font-size: 1rem;
    color: var(--text-secondary);
    margin: 0;
}

.newsletter-input-group {
    display: flex;
    gap: 0.75rem;
}

.newsletter-input-group input {
    flex: 1;
    padding: 0.875rem 1rem;
    font-family: var(--font-body);
    font-size: 1rem;
    color: var(--text-primary);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-full);
    transition: all var(--duration-fast);
}

.newsletter-input-group input::placeholder {
    color: var(--text-tertiary);
}

.newsletter-input-group input:focus {
    outline: none;
    border-color: var(--gray-400);
    background: var(--bg-primary);
}

.newsletter-input-group .btn {
    flex-shrink: 0;
}

.newsletter-privacy {
    font-size: 0.8125rem;
    color: var(--text-tertiary);
    margin-top: var(--space-sm);
    margin-bottom: 0;
}

/* ============================================
   RESPONSIVE - TABLET (1024px)
   ============================================ */

@media (max-width: 1024px) {
    .related-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .related-card:last-child {
        display: none;
    }

    .newsletter-box {
        grid-template-columns: 1fr;
        gap: var(--space-lg);
        text-align: center;
    }

    .newsletter-content .section-label {
        display: inline-block;
    }
}

/* ============================================
   RESPONSIVE - MOBILE (768px)
   ============================================ */

@media (max-width: 768px) {
    .article-header {
        padding: calc(70px + var(--space-xl)) 0 var(--space-xl);
    }

    .article-title {
        font-size: 1.875rem;
        max-width: 100%;
    }

    .article-subtitle {
        font-size: 1.0625rem;
    }

    .article-content {
        padding: var(--space-xl) 0;
    }

    .article-content .lead {
        font-size: 1.125rem;
    }

    .article-content h2 {
        font-size: 1.5rem;
        margin-top: var(--space-xl);
    }

    .article-content p,
    .article-content ul li,
    .article-content ol li {
        font-size: 1rem;
    }

    .article-content blockquote {
        padding: var(--space-md);
        margin: var(--space-lg) 0;
    }

    .article-content blockquote p {
        font-size: 1.125rem;
    }

    .article-content pre {
        padding: var(--space-md);
        margin: var(--space-md) 0;
        border-radius: var(--radius-md);
    }

    .toc {
        padding: var(--space-md);
    }

    .callout {
        padding: var(--space-md);
    }

    .stat-highlight {
        padding: var(--space-lg);
    }

    .stat-highlight .stat-value {
        font-size: 2.5rem;
    }

    .checklist-box {
        padding: var(--space-lg);
    }

    .checklist-title {
        font-size: 1.125rem;
    }

    .article-cta {
        padding: var(--space-lg);
    }

    .article-cta h3 {
        font-size: 1.25rem;
    }

    .article-footer {
        padding: var(--space-lg) 0;
    }

    .article-tags {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }

    .tags-label {
        margin-right: 0;
    }

    .article-tags .tag:first-of-type {
        margin-left: 0;
    }

    .article-share {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }

    .author-bio {
        flex-direction: column;
        gap: var(--space-sm);
    }

    .author-bio-avatar {
        width: 56px;
        height: 56px;
    }

    .related-articles {
        padding: var(--space-xl) 0;
    }

    .related-title {
        font-size: 1.5rem;
    }

    .related-grid {
        grid-template-columns: 1fr;
        gap: var(--space-md);
    }

    .related-card:last-child {
        display: block;
    }

    .related-card:hover {
        transform: none;
    }

    .related-card-link {
        padding: var(--space-md);
    }

    .related-card-title {
        font-size: 1rem;
    }

    .newsletter-section {
        padding: var(--space-xl) 0;
    }

    .newsletter-box {
        padding: var(--space-lg);
    }

    .newsletter-title {
        font-size: 1.5rem;
    }

    .newsletter-input-group {
        flex-direction: column;
    }

    .newsletter-input-group .btn {
        width: 100%;
    }
}

/* ============================================
   RESPONSIVE - SMALL MOBILE (480px)
   ============================================ */

@media (max-width: 480px) {
    .article-title {
        font-size: 1.625rem;
    }

    .article-meta {
        font-size: 0.75rem;
    }

    .stat-highlight .stat-value {
        font-size: 2rem;
    }

    .checklist li {
        font-size: 0.875rem;
    }
}