/*
Theme Name: Tech Blog Clean
Theme URI: https://example.com/tech-blog-clean
Description: A lightweight, modern WordPress theme optimized for technical blogs. Features dark mode, clean design inspired by modern tech blogs, and excellent performance for SEO.
Version: 1.0.0
Author: Your Name
Author URI: https://example.com
License: GNU General Public License v2 or later
License URI: http://www.gnu.org/licenses/gpl-2.0.html
Text Domain: tech-blog-clean
Tags: blog, one-column, custom-colors, dark-mode, accessibility-ready, featured-images, threaded-comments, translation-ready

Tech Blog Clean WordPress Theme
*/

/* ==========================================================================
   CSS Variables - Light & Dark Mode
   ========================================================================== */

:root {
  /* Colors - Light Mode (Inspired by Toss.tech) */
  --color-primary: #1E40AF;
  --color-primary-hover: #1E3A8A;
  --color-text-primary: #191f28;
  --color-text-secondary: #4e5968;
  --color-text-tertiary: #8b95a1;
  --color-background: #ffffff;
  --color-background-secondary: #f8f9fa;
  --color-border: rgba(0, 29, 58, 0.18);
  --color-shadow: rgba(0, 0, 33, 0.07);
  --color-shadow-hover: rgba(0, 0, 33, 0.15);

  /* Spacing */
  --space-xs: 8px;
  --space-sm: 12px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;

  /* Typography */
  --font-family-base: -apple-system, BlinkMacSystemFont, "Segoe UI", "Apple SD Gothic Neo", "Noto Sans KR", sans-serif;
  --font-size-xs: 0.75rem;     /* 12px */
  --font-size-sm: 0.875rem;    /* 14px */
  --font-size-base: 1rem;      /* 16px */
  --font-size-lg: 1.125rem;    /* 18px */
  --font-size-xl: 1.25rem;     /* 20px */
  --font-size-2xl: 1.5rem;     /* 24px */
  --font-size-3xl: 1.875rem;   /* 30px */
  --font-size-4xl: 2.25rem;    /* 36px */

  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;

  /* Layout */
  --container-max-width: 1400px;
  --header-height: 64px;
  --border-radius: 12px;
  --border-radius-sm: 8px;
  --sidebar-width: 200px;

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-base: 0.3s ease;
}

/* Dark Mode Variables */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --color-primary: #3B82F6;
    --color-primary-hover: #60A5FA;
    --color-text-primary: #e8eaed;
    --color-text-secondary: #c4c7cc;
    --color-text-tertiary: #9aa0a6;
    --color-background: #1a1a1a;
    --color-background-secondary: #242424;
    --color-border: rgba(255, 255, 255, 0.12);
    --color-shadow: rgba(0, 0, 0, 0.3);
    --color-shadow-hover: rgba(0, 0, 0, 0.5);
  }
}

:root[data-theme="dark"] {
  --color-primary: #3B82F6;
  --color-primary-hover: #60A5FA;
  --color-text-primary: #e8eaed;
  --color-text-secondary: #c4c7cc;
  --color-text-tertiary: #9aa0a6;
  --color-background: #1a1a1a;
  --color-background-secondary: #242424;
  --color-border: rgba(255, 255, 255, 0.12);
  --color-shadow: rgba(0, 0, 0, 0.3);
  --color-shadow-hover: rgba(0, 0, 0, 0.5);
}

/* ==========================================================================
   Base Styles
   ========================================================================== */

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text-primary);
  background-color: var(--color-background);
  transition: background-color var(--transition-base), color var(--transition-base);
  scroll-padding-top: calc(var(--header-height) + var(--space-lg));
}

/* ==========================================================================
   Typography
   ========================================================================== */

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: var(--line-height-tight);
  margin-bottom: var(--space-md);
  color: var(--color-text-primary);
  scroll-margin-top: calc(var(--header-height) + var(--space-lg));
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }
h4 { font-size: var(--font-size-xl); }
h5 { font-size: var(--font-size-lg); }
h6 { font-size: var(--font-size-base); }

p {
  margin-bottom: var(--space-md);
  color: var(--color-text-secondary);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-hover);
}

strong, b {
  font-weight: 700;
}

em, i {
  font-style: italic;
}

ul, ol {
  margin-bottom: var(--space-md);
  padding-left: var(--space-lg);
}

li {
  margin-bottom: var(--space-xs);
  color: var(--color-text-secondary);
}

blockquote {
  margin: var(--space-lg) 0;
  padding: var(--space-md) var(--space-lg);
  border-left: 4px solid var(--color-primary);
  background-color: var(--color-background-secondary);
  color: var(--color-text-secondary);
  font-style: italic;
}

/* ==========================================================================
   Layout
   ========================================================================== */

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

/* ==========================================================================
   Header
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--color-background);
  border-bottom: 1px solid var(--color-border);
  transition: background-color var(--transition-base);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-height);
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: var(--space-sm) var(--space-lg);
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.site-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  margin: 0;
}

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

.site-title a:hover {
  color: var(--color-primary);
}

.header-nav {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.main-navigation ul {
  display: flex;
  list-style: none;
  gap: var(--space-lg);
  margin: 0;
  padding: 0;
}

.main-navigation a {
  color: var(--color-text-secondary);
  font-size: var(--font-size-base);
  font-weight: 500;
  transition: color var(--transition-fast);
}

.main-navigation a:hover,
.main-navigation .current-menu-item a {
  color: var(--color-primary);
}

/* Dark Mode Toggle */
.dark-mode-toggle {
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-xs);
  color: var(--color-text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color var(--transition-fast);
}

.dark-mode-toggle:hover {
  color: var(--color-primary);
}

.dark-mode-toggle svg {
  width: 24px;
  height: 24px;
  fill: currentColor;
}

/* ==========================================================================
   Main Content Area
   ========================================================================== */

.site-main {
  min-height: calc(100vh - var(--header-height) - 200px);
  padding: var(--space-2xl) 0;
}

/* ==========================================================================
   Post Cards (Homepage & Archives)
   ========================================================================== */

.posts-grid {
  display: grid;
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
}

.post-card {
  background-color: var(--color-background);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: 0 2px 8px var(--color-shadow);
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.post-card:hover {
  box-shadow: 0 8px 16px var(--color-shadow-hover);
  transform: translateY(-2px);
}

.post-card-thumbnail {
  position: relative;
  width: 100%;
  height: 240px;
  overflow: hidden;
  background: linear-gradient(135deg, var(--color-primary) 0%, #60A5FA 100%);
}

.post-card-thumbnail img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-base);
}

.post-card:hover .post-card-thumbnail img {
  transform: scale(1.05);
}

.post-card-content {
  padding: var(--space-lg);
}

.post-card-meta {
  display: flex;
  gap: var(--space-md);
  margin-bottom: var(--space-sm);
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
}

.post-card-title {
  font-size: var(--font-size-2xl);
  margin-bottom: var(--space-sm);
}

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

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

.post-card-excerpt {
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

/* ==========================================================================
   Single Post
   ========================================================================== */

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

.single-post-title {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--space-md);
}

.single-post-meta {
  display: flex;
  gap: var(--space-lg);
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
}

.post-content {
  font-size: var(--font-size-lg);
  line-height: var(--line-height-relaxed);
  color: var(--color-text-secondary);
}

.post-content h2 {
  margin-top: var(--space-2xl);
  margin-bottom: var(--space-md);
}

.post-content h3 {
  margin-top: var(--space-xl);
  margin-bottom: var(--space-md);
}

.post-content img {
  max-width: 100%;
  height: auto;
  border-radius: var(--border-radius-sm);
  margin: var(--space-lg) 0;
}

/* ==========================================================================
   Table of Contents (TOC)
   ========================================================================== */

.table-of-contents {
  background-color: var(--color-background-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: var(--space-lg);
  margin-bottom: var(--space-xl);
}

.table-of-contents h2 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--space-md);
}

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

.toc-list li {
  margin-bottom: var(--space-sm);
}

.toc-list a {
  color: var(--color-text-secondary);
  font-size: var(--font-size-base);
}

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

.toc-list .toc-h3 {
  padding-left: var(--space-md);
}

/* ==========================================================================
   Code Blocks
   ========================================================================== */

code {
  font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
  font-size: 0.9em;
  background-color: var(--color-background-secondary);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--color-primary);
}

pre {
  background-color: var(--color-background-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-sm);
  padding: var(--space-md);
  overflow-x: auto;
  margin: var(--space-lg) 0;
}

pre code {
  background: none;
  padding: 0;
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  line-height: var(--line-height-relaxed);
}

/* ==========================================================================
   Pagination
   ========================================================================== */

.pagination {
  display: flex;
  justify-content: center;
  gap: var(--space-sm);
  margin: var(--space-2xl) 0;
}

.pagination a,
.pagination span {
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-sm);
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.pagination a:hover {
  background-color: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

.pagination .current {
  background-color: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.site-footer {
  background-color: var(--color-background-secondary);
  border-top: 1px solid var(--color-border);
  padding: var(--space-2xl) 0;
  margin-top: var(--space-3xl);
}

.footer-content {
  text-align: center;
  color: var(--color-text-tertiary);
  font-size: var(--font-size-sm);
}

/* ==========================================================================
   Search Form
   ========================================================================== */

.search-form {
  display: flex;
  gap: var(--space-sm);
  margin-bottom: var(--space-xl);
}

.search-form input[type="search"] {
  flex: 1;
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-sm);
  font-size: var(--font-size-base);
  background-color: var(--color-background);
  color: var(--color-text-primary);
}

.search-form button {
  padding: var(--space-sm) var(--space-lg);
  background-color: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--border-radius-sm);
  font-size: var(--font-size-base);
  font-weight: 500;
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

.search-form button:hover {
  background-color: var(--color-primary-hover);
}

/* ==========================================================================
   Responsive Design
   ========================================================================== */

@media (max-width: 768px) {
  :root {
    --font-size-4xl: 1.875rem;  /* 30px */
    --font-size-3xl: 1.5rem;    /* 24px */
    --space-2xl: 32px;
    --space-3xl: 48px;
    --header-height: 60px;
  }

  .header-inner {
    flex-wrap: wrap;
    padding: 0 var(--space-md);
  }

  .site-title {
    font-size: var(--font-size-lg);
  }

  .main-navigation ul {
    gap: var(--space-md);
  }

  .main-navigation a {
    font-size: var(--font-size-sm);
  }

  .post-card-thumbnail {
    height: 180px;
  }

  .single-post-meta {
    flex-direction: column;
    gap: var(--space-xs);
  }

  .site-footer {
    padding: var(--space-xl) 0;
    margin-top: var(--space-2xl);
  }

  .footer-content {
    font-size: var(--font-size-xs);
  }

  .posts-grid {
    gap: var(--space-md);
  }

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

  .category-filter-menu {
    gap: var(--space-xs);
    margin-bottom: var(--space-lg);
  }

  .category-filter-item {
    padding: var(--space-xs) var(--space-md);
    font-size: var(--font-size-sm);
  }
}

/* Z Fold and foldable devices (unfolded narrow state) */
@media (max-width: 680px) {
  .posts-grid {
    grid-template-columns: 1fr;
    gap: var(--space-sm);
  }

  .post-card {
    padding: var(--space-sm);
  }

  .post-card-thumbnail {
    height: 160px;
  }

  .post-card-title {
    font-size: var(--font-size-base);
  }
}

@media (max-width: 480px) {
  :root {
    --header-height: 54px;
  }

  .container,
  .header-inner {
    padding: 0 var(--space-sm);
  }

  .site-main {
    padding: var(--space-lg) 0;
  }

  .site-title {
    font-size: var(--font-size-base);
  }

  .main-navigation ul {
    flex-wrap: wrap;
    gap: var(--space-xs);
  }

  .main-navigation a {
    font-size: var(--font-size-xs);
    padding: var(--space-xs) var(--space-sm);
  }

  .site-footer {
    padding: var(--space-md) 0;
    margin-top: var(--space-xl);
  }

  .post-card {
    padding: var(--space-xs);
  }

  .post-card-thumbnail {
    height: 140px;
  }

  .post-card-content {
    padding: var(--space-sm);
  }

  .post-card-title {
    font-size: var(--font-size-sm);
  }

  .post-card-excerpt {
    font-size: var(--font-size-xs);
  }

  .posts-grid {
    gap: var(--space-xs);
  }

  .category-filter-menu {
    gap: 4px;
    margin-bottom: var(--space-md);
    padding-bottom: var(--space-xs);
  }

  .category-filter-item {
    padding: 6px var(--space-sm);
    font-size: var(--font-size-xs);
  }

  .category-filter-item.active::after {
    bottom: -10px;
    height: 2px;
  }
}

/* ==========================================================================
   Utility Classes
   ========================================================================== */

.screen-reader-text {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.no-results {
  text-align: center;
  padding: var(--space-3xl) 0;
}

.no-results h1 {
  font-size: var(--font-size-3xl);
  margin-bottom: var(--space-md);
}

/* ==========================================================================
   Archive Headers
   ========================================================================== */

.archive-header,
.search-header {
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid var(--color-border);
}

.archive-title,
.search-title {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--space-md);
}

.archive-description {
  color: var(--color-text-secondary);
  font-size: var(--font-size-lg);
  line-height: var(--line-height-relaxed);
  margin-top: var(--space-md);
}

.archive-meta {
  margin-top: var(--space-md);
  color: var(--color-text-tertiary);
  font-size: var(--font-size-sm);
}

.search-results-count {
  margin-bottom: var(--space-lg);
  color: var(--color-text-tertiary);
  font-size: var(--font-size-sm);
}

/* ==========================================================================
   Post Tags
   ========================================================================== */

.post-tags {
  margin-top: var(--space-2xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-border);
}

.post-tags h3 {
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-md);
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.tag-link {
  display: inline-block;
  padding: var(--space-xs) var(--space-md);
  background-color: var(--color-background-secondary);
  color: var(--color-text-secondary);
  border-radius: 999px;
  font-size: var(--font-size-sm);
  transition: all var(--transition-fast);
}

.tag-link:hover {
  background-color: var(--color-primary);
  color: white;
}

/* ==========================================================================
   Post Navigation (Previous/Next)
   ========================================================================== */

.post-navigation {
  margin-top: var(--space-2xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-border);
}

.nav-links {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-lg);
}

.nav-previous,
.nav-next {
  display: block;
  padding: var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-sm);
  transition: all var(--transition-fast);
  text-decoration: none;
  color: var(--color-text-primary);
}

.nav-previous:hover,
.nav-next:hover {
  border-color: var(--color-primary);
  background-color: var(--color-background-secondary);
  transform: translateY(-2px);
  box-shadow: 0 4px 8px var(--color-shadow);
}

.nav-subtitle {
  display: block;
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-xs);
}

.nav-title {
  display: block;
  color: var(--color-text-primary);
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav-previous:hover .nav-title,
.nav-next:hover .nav-title {
  color: var(--color-primary);
}

/* ==========================================================================
   Buttons
   ========================================================================== */

.button {
  display: inline-block;
  padding: var(--space-sm) var(--space-lg);
  background-color: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--border-radius-sm);
  font-size: var(--font-size-base);
  font-weight: 500;
  text-align: center;
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

.button:hover {
  background-color: var(--color-primary-hover);
  color: white;
}

/* ==========================================================================
   404 Error Page
   ========================================================================== */

.error-404 {
  text-align: center;
  padding: var(--space-3xl) 0;
}

.error-404 .page-title {
  font-size: 6rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--space-sm);
  line-height: 1;
}

.error-subtitle {
  font-size: var(--font-size-2xl);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-xl);
}

.error-404 .page-content {
  max-width: 600px;
  margin: 0 auto;
}

.error-404-actions {
  margin: var(--space-xl) 0;
}

.error-404 .suggested-content {
  margin-top: var(--space-3xl);
  text-align: left;
}

.error-404 .suggested-content h3 {
  margin-top: var(--space-2xl);
  margin-bottom: var(--space-lg);
}

/* ==========================================================================
   Category List
   ========================================================================== */

.category-list {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--space-md);
}

.category-list li a {
  display: block;
  padding: var(--space-sm) var(--space-md);
  background-color: var(--color-background-secondary);
  border-radius: var(--border-radius-sm);
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.category-list li a:hover {
  background-color: var(--color-primary);
  color: white;
}

.category-list .count {
  color: var(--color-text-tertiary);
  font-size: var(--font-size-sm);
}

.category-list li a:hover .count {
  color: rgba(255, 255, 255, 0.8);
}

/* ==========================================================================
   Comments
   ========================================================================== */

.comments-area {
  margin-top: var(--space-3xl);
  padding-top: var(--space-2xl);
  border-top: 1px solid var(--color-border);
}

.comments-title {
  font-size: var(--font-size-2xl);
  margin-bottom: var(--space-lg);
}

.comment-list {
  list-style: none;
  padding: 0;
}

.comment-list li {
  list-style: none;
}

.comment-list ul,
.comment-list ol {
  list-style: none;
  padding: 0;
}

.comment-list ul li,
.comment-list ol li {
  list-style: none;
}

.comment {
  margin-bottom: var(--space-lg);
  padding: var(--space-lg);
  background-color: var(--color-background-secondary);
  border-radius: var(--border-radius-sm);
}

.comment-author {
  font-weight: 700;
  margin-bottom: var(--space-xs);
}

.comment-metadata {
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-sm);
}

.comment-content {
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

.comment-reply-link {
  font-size: var(--font-size-sm);
  color: var(--color-primary);
}

.comment-form input[type="text"],
.comment-form input[type="email"],
.comment-form input[type="url"],
.comment-form textarea {
  width: 100%;
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-sm);
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  background-color: var(--color-background);
  color: var(--color-text-primary);
  margin-bottom: var(--space-md);
}

.comment-form textarea {
  min-height: 150px;
  resize: vertical;
}

.comment-form input[type="submit"] {
  padding: var(--space-sm) var(--space-lg);
  background-color: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--border-radius-sm);
  font-size: var(--font-size-base);
  font-weight: 500;
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

.comment-form input[type="submit"]:hover {
  background-color: var(--color-primary-hover);
}

/* ==========================================================================
   AdSense Placeholder Areas
   ========================================================================== */

.ad-space {
  margin: var(--space-2xl) 0;
  padding: var(--space-lg);
  min-height: 250px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-background-secondary);
  border: 1px dashed var(--color-border);
  border-radius: var(--border-radius-sm);
  color: var(--color-text-tertiary);
  font-size: var(--font-size-sm);
}

/* Hide ad placeholder text when actual ad is inserted */
.ad-space:has(ins) {
  background: none;
  border: none;
  padding: 0;
}

/* ==========================================================================
   Single Post Thumbnail
   ========================================================================== */

.single-post-thumbnail {
  margin-bottom: var(--space-xl);
  border-radius: var(--border-radius);
  overflow: hidden;
}

.single-post-thumbnail img {
  width: 100%;
  height: auto;
  display: block;
}

/* ==========================================================================
   Header Search Form
   ========================================================================== */

.header-search-form {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  position: relative;
}

.header-search-form input[type="search"] {
  width: 300px;
  padding: var(--space-xs) var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-sm);
  font-size: var(--font-size-sm);
  background-color: var(--color-background);
  color: var(--color-text-primary);
  transition: border-color var(--transition-fast);
}

.header-search-form input[type="search"]:focus {
  outline: none;
  border-color: var(--color-primary);
}

.header-search-form button {
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-xs);
  color: var(--color-text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color var(--transition-fast);
}

.header-search-form button:hover {
  color: var(--color-primary);
}

/* ==========================================================================
   Two Column Layout (Content + Sidebar)
   ========================================================================== */

.content-with-sidebar {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: var(--space-2xl);
  align-items: start;
}

.main-content {
  min-width: 0;
}

/* ==========================================================================
   Category Filter Menu
   ========================================================================== */

.category-filter-menu {
  display: flex;
  gap: var(--space-xs);
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-md);
  border-bottom: 2px solid var(--color-border);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.category-filter-item {
  padding: var(--space-sm) var(--space-lg);
  font-size: var(--font-size-base);
  font-weight: 600;
  color: var(--color-text-secondary);
  text-decoration: none;
  border-radius: var(--border-radius-sm);
  transition: all var(--transition-fast);
  white-space: nowrap;
  position: relative;
}

.category-filter-item:hover {
  color: var(--color-primary);
  background-color: var(--color-background-secondary);
}

.category-filter-item.active {
  color: var(--color-primary);
  background-color: var(--color-background-secondary);
}

.category-filter-item.active::after {
  content: '';
  position: absolute;
  bottom: -14px;
  left: 50%;
  transform: translateX(-50%);
  width: 60%;
  height: 3px;
  background-color: var(--color-primary);
  border-radius: 2px;
}

/* ==========================================================================
   Tile Grid for Homepage
   ========================================================================== */

.posts-tile-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
}

.post-tile {
  background-color: var(--color-background);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: 0 2px 8px var(--color-shadow);
  transition: box-shadow var(--transition-base), transform var(--transition-base);
  aspect-ratio: 2 / 1;
  display: flex;
  flex-direction: column;
}

.post-tile:hover {
  box-shadow: 0 8px 16px var(--color-shadow-hover);
  transform: translateY(-4px);
}

.post-tile-link {
  display: flex;
  flex-direction: column;
  height: 100%;
  color: inherit;
  text-decoration: none;
}

.post-tile-thumbnail {
  position: relative;
  width: 100%;
  height: 50%;
  overflow: hidden;
  background: linear-gradient(135deg, var(--color-primary) 0%, #60A5FA 100%);
}

.post-tile-thumbnail img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-base);
}

.post-tile:hover .post-tile-thumbnail img {
  transform: scale(1.05);
}

.post-tile-content {
  padding: var(--space-sm);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  flex: 1;
}

.post-tile-title {
  font-size: var(--font-size-base);
  margin-bottom: var(--space-xs);
  line-height: var(--line-height-tight);
  color: var(--color-text-primary);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.post-tile-meta {
  display: flex;
  gap: var(--space-sm);
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
  margin-top: auto;
}

.post-tile-category {
  color: var(--color-primary);
  font-weight: 500;
}

/* ==========================================================================
   Sidebar Styles
   ========================================================================== */

.sidebar {
  position: sticky;
  top: calc(var(--header-height) + var(--space-lg));
  padding-bottom: var(--space-lg);
}

.sidebar-widget {
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-2xl);
  border-bottom: 2px solid var(--color-border);
}

.sidebar-widget:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.widget-title {
  font-size: var(--font-size-lg);
  font-weight: 700;
  margin-bottom: var(--space-md);
  color: var(--color-text-primary);
}

.widget-title a {
  color: var(--color-text-primary);
  transition: color var(--transition-fast);
}

.widget-title a:hover {
  color: var(--color-primary);
}

.widget-posts-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.widget-post-item {
  margin-bottom: var(--space-sm);
}

.widget-post-item:last-child {
  margin-bottom: 0;
}

.widget-post-item a {
  display: flex;
  gap: var(--space-xs);
  padding: var(--space-xs);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-sm);
  color: inherit;
  text-decoration: none;
  transition: all var(--transition-fast);
}

.widget-post-item a:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
  background-color: var(--color-background-secondary);
  box-shadow: 0 2px 4px var(--color-shadow);
}

.widget-post-item a:hover .widget-post-title {
  color: var(--color-primary);
}

.widget-post-thumbnail {
  width: 42px;
  height: 42px;
  flex-shrink: 0;
  border-radius: var(--border-radius-sm);
  overflow: hidden;
  background: linear-gradient(135deg, var(--color-primary) 0%, #60A5FA 100%);
}

.widget-post-thumbnail img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.widget-post-content {
  flex: 1;
  min-width: 0;
}

.widget-post-title {
  font-size: var(--font-size-xs);
  font-weight: 600;
  line-height: var(--line-height-tight);
  margin-bottom: 2px;
  color: var(--color-text-primary);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.widget-post-date {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
}

/* ==========================================================================
   Single Post Layout with TOC Sidebar
   ========================================================================== */

.single-post-layout {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr var(--sidebar-width);
  gap: var(--space-2xl);
  align-items: start;
  max-width: var(--container-max-width);
  margin: 0 auto;
}

.single-post-layout-no-toc {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr var(--sidebar-width);
  gap: var(--space-2xl);
  align-items: start;
  max-width: var(--container-max-width);
  margin: 0 auto;
}

.single-post-layout-no-toc .toc-sidebar {
  visibility: hidden;
}

.single-post-content-wrapper {
  min-width: 0;
}

.toc-sidebar {
  position: sticky;
  top: calc(var(--header-height) + var(--space-lg));
}

.toc-sticky {
  padding: var(--space-lg) 0;
}

.toc-title {
  font-size: var(--font-size-base);
  font-weight: 700;
  margin-bottom: var(--space-md);
  color: var(--color-text-primary);
}

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

.toc-list li {
  margin-bottom: var(--space-sm);
}

.toc-list a {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  line-height: var(--line-height-normal);
  transition: color var(--transition-fast);
  display: block;
}

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

.toc-list .toc-h3 {
  padding-left: var(--space-md);
}

.toc-list .toc-h3 a {
  font-size: var(--font-size-xs);
}

/* Remove inline TOC if exists */
.table-of-contents {
  display: none;
}

/* ==========================================================================
   Ad Sidebar (Right side for Google Adsense)
   ========================================================================== */

.ad-sidebar {
  position: sticky;
  top: calc(var(--header-height) + var(--space-lg));
}

.ad-sidebar-sticky {
  min-height: 300px;
}

/* ==========================================================================
   Responsive Adjustments
   ========================================================================== */

@media (max-width: 1024px) {
  .content-with-sidebar {
    grid-template-columns: 1fr;
    max-width: 100%;
  }

  .main-content {
    max-width: 100%;
  }

  .sidebar {
    display: none;
  }

  .single-post-layout,
  .single-post-layout-no-toc {
    grid-template-columns: 1fr;
    max-width: 100%;
  }

  .toc-sidebar,
  .ad-sidebar {
    display: none;
  }

  .single-post-content-wrapper {
    max-width: 100%;
  }

  .posts-tile-grid {
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  }

  .container {
    max-width: 100%;
  }
}

@media (max-width: 768px) {
  .header-search-form input[type="search"] {
    width: 200px;
  }

  .posts-tile-grid {
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: var(--space-md);
  }

  .post-tile-title {
    font-size: var(--font-size-base);
  }
}

/* Z Fold and foldable devices */
@media (max-width: 680px) {
  .header-inner {
    min-height: auto;
    padding: var(--space-xs) var(--space-sm);
  }

  .main-navigation {
    width: 100%;
    order: 3;
  }

  .main-navigation ul {
    justify-content: flex-start;
    flex-wrap: wrap;
  }

  .header-search-form {
    order: 2;
  }

  .header-search-form input[type="search"] {
    width: 160px;
  }

  .posts-tile-grid {
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: var(--space-sm);
  }

  .post-tile {
    aspect-ratio: 1 / 1;
  }

  .post-tile-content {
    padding: var(--space-xs);
  }

  .post-tile-title {
    font-size: var(--font-size-sm);
    margin-bottom: 4px;
  }
}

@media (max-width: 480px) {
  .header-inner {
    padding: var(--space-xs) var(--space-sm);
  }

  .main-navigation {
    width: 100%;
    order: 3;
  }

  .header-search-form {
    width: 100%;
    order: 2;
  }

  .header-search-form input[type="search"] {
    width: 100%;
    font-size: var(--font-size-sm);
  }

  .posts-tile-grid {
    grid-template-columns: 1fr;
    gap: var(--space-xs);
  }

  .post-tile {
    aspect-ratio: 3 / 1;
  }

  .post-tile-thumbnail {
    height: 40%;
  }

  .post-tile-content {
    padding: var(--space-xs);
  }

  .post-tile-title {
    font-size: var(--font-size-sm);
    -webkit-line-clamp: 1;
  }

  .post-tile-meta {
    font-size: 10px;
  }
}