/* ==========================================================================
   Engineer Blog - メインスタイルシート
   技術ブログ向け: 可読性重視のタイポグラフィ + レスポンシブデザイン
   ========================================================================== */

/* ---------- CSS Custom Properties ---------- */
:root {
  /* Colors */
  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-text: #1a1a2e;
  --color-text-secondary: #64748b;
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-primary-light: #dbeafe;
  --color-accent: #059669;
  --color-accent-light: #d1fae5;
  --color-border: #e2e8f0;
  --color-code-bg: #1e1e2e;
  --color-tag-bg: #eff6ff;
  --color-tag-text: #2563eb;
  --color-warning: #f59e0b;
  --color-footer-bg: #0f172a;
  --color-footer-text: #94a3b8;

  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
  --gradient-hero: linear-gradient(135deg, #0f172a 0%, #1e1b4b 40%, #1e3a5f 100%);
  --gradient-card-hover: linear-gradient(135deg, #eff6ff 0%, #f5f3ff 100%);
  --gradient-accent: linear-gradient(135deg, #059669 0%, #0891b2 100%);

  /* Typography */
  --font-sans: "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", "Source Code Pro", Consolas, monospace;
  --font-size-base: 1rem;
  --line-height-body: 1.85;
  --line-height-heading: 1.35;

  /* Spacing */
  --content-width: 880px;
  --content-wide: 1280px;
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2.5rem;
  --spacing-2xl: 4rem;
  --spacing-3xl: 6rem;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.12), 0 4px 8px rgba(0,0,0,0.04);
  --shadow-glow: 0 0 20px rgba(37,99,235,0.15);

  /* Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  /* Transitions */
  --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---------- Reset & Base ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: var(--line-height-body);
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
}

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

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

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

/* ---------- Reading Progress Bar ---------- */
.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 200;
  background: transparent;
}
.reading-progress__bar {
  height: 100%;
  width: 0;
  background: var(--gradient-primary);
  transition: width 0.1s linear;
  border-radius: 0 2px 2px 0;
}

/* ---------- Back to Top ---------- */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
  color: var(--color-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all var(--transition-base);
  z-index: 50;
}
.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.back-to-top:hover {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

/* ---------- Fade In Animation ---------- */
.fade-in-section {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}
.fade-in-section.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- Site Header ---------- */
.site-header {
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(12px) saturate(180%);
  -webkit-backdrop-filter: blur(12px) saturate(180%);
  border-bottom: 1px solid rgba(226,232,240,0.6);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: box-shadow var(--transition-base);
}
.site-header.is-scrolled {
  box-shadow: 0 1px 12px rgba(0,0,0,0.06);
}

.site-header__inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: var(--spacing-md) var(--spacing-lg);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-lg);
}

.site-branding {
  flex-shrink: 0;
}

.site-title {
  font-size: 1.25rem;
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-decoration: none;
  letter-spacing: -0.02em;
}

.site-title:hover {
  opacity: 0.8;
}

.site-description {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin: 0;
}

/* Mobile menu toggle */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  padding: var(--spacing-sm);
  cursor: pointer;
  flex-direction: column;
  gap: 5px;
}

.menu-toggle__bar {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: transform 0.3s;
}

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

.main-navigation a {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  position: relative;
  padding-bottom: 4px;
}

.main-navigation a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--gradient-primary);
  border-radius: 1px;
  transition: width var(--transition-base);
}

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

.main-navigation a:hover::after {
  width: 100%;
}

.main-navigation .current-menu-item a {
  color: var(--color-primary);
}
.main-navigation .current-menu-item a::after {
  width: 100%;
}

/* ---------- Site Main ---------- */
.site-main {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: var(--spacing-xl) var(--spacing-lg);
  min-height: 60vh;
}

.content-area {
  max-width: var(--content-width);
  margin: 0 auto;
}

/* ---------- Archive / Post List ---------- */
.archive-header {
  margin-bottom: var(--spacing-xl);
}

.page-title {
  font-size: 1.75rem;
  font-weight: 700;
  line-height: var(--line-height-heading);
}

.post-list {
  display: grid;
  gap: var(--spacing-lg);
}

.post-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: box-shadow var(--transition-base), transform var(--transition-base);
  border: 1px solid transparent;
}

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

.post-card__link {
  display: flex;
  text-decoration: none;
  color: inherit;
}

.post-card__thumbnail {
  flex-shrink: 0;
  width: 200px;
  margin: 0;
}

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

.post-card__body {
  padding: var(--spacing-lg);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.post-card__category {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--color-primary);
  background: var(--color-tag-bg);
  padding: 2px 10px;
  border-radius: 20px;
  letter-spacing: 0.03em;
}

.post-card__title {
  font-size: 1.1rem;
  font-weight: 700;
  line-height: var(--line-height-heading);
  margin: 0;
}

.post-card__excerpt {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  margin: 0;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.post-card__date {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin-top: auto;
}

/* ---------- Single Post ---------- */
.single-post {
  margin: 0 auto;
}

.entry-header {
  margin-bottom: var(--spacing-xl);
}

.entry-meta {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-md);
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.entry-category a {
  display: inline-block;
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 700;
  transition: all var(--transition-fast);
  letter-spacing: 0.02em;
}
.entry-category a:hover {
  background: var(--color-primary);
  color: #fff;
}

.entry-title {
  font-size: 2rem;
  font-weight: 800;
  line-height: var(--line-height-heading);
  margin: 0;
  letter-spacing: -0.02em;
}

.entry-thumbnail {
  margin: var(--spacing-lg) 0 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

/* ---------- Entry Body (TOC + Content) ---------- */
.entry-body {
  position: relative;
}

/* ---------- Table of Contents ---------- */
.toc-container {
  background: linear-gradient(135deg, #fafbff 0%, #f8fafc 100%);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
  position: relative;
  overflow: hidden;
}
.toc-container::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--gradient-primary);
  border-radius: 2px;
}

.toc-title {
  font-size: 1rem;
  font-weight: 700;
  margin: 0 0 var(--spacing-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}
.toc-title::before {
  content: '';
  display: inline-block;
  width: 20px;
  height: 20px;
  background: var(--gradient-primary);
  border-radius: 4px;
  opacity: 0.2;
}

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

.toc-nav li {
  counter-increment: toc;
  margin-bottom: var(--spacing-xs);
}

.toc-nav li::before {
  content: counters(toc, ".") ". ";
  color: var(--color-text-secondary);
  font-size: 0.85rem;
}

.toc-nav a {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
}

.toc-nav a:hover,
.toc-nav a.is-active {
  color: var(--color-primary);
}

.toc-nav ol ol {
  padding-left: var(--spacing-lg);
  margin-top: var(--spacing-xs);
}

/* ---------- Entry Content ---------- */
.entry-content {
  font-size: 1.05rem;
  line-height: var(--line-height-body);
}

.entry-content h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin: var(--spacing-2xl) 0 var(--spacing-lg);
  padding: var(--spacing-sm) 0 var(--spacing-sm) var(--spacing-md);
  border-left: 4px solid transparent;
  border-image: var(--gradient-primary) 1;
  border-bottom: none;
  line-height: var(--line-height-heading);
  position: relative;
}

.entry-content h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin: var(--spacing-xl) 0 var(--spacing-md);
  line-height: var(--line-height-heading);
  color: var(--color-text);
  padding-left: var(--spacing-md);
  border-left: 3px solid var(--color-accent);
}

.entry-content h4 {
  font-size: 1.1rem;
  font-weight: 600;
  margin: var(--spacing-lg) 0 var(--spacing-md);
}

.entry-content p {
  margin: 0 0 var(--spacing-lg);
}

.entry-content ul,
.entry-content ol {
  margin: 0 0 var(--spacing-lg);
  padding-left: var(--spacing-xl);
}

.entry-content li {
  margin-bottom: var(--spacing-sm);
}

.entry-content blockquote {
  margin: var(--spacing-lg) 0;
  padding: var(--spacing-lg) var(--spacing-lg) var(--spacing-lg) var(--spacing-xl);
  border-left: 4px solid transparent;
  border-image: var(--gradient-primary) 1;
  background: linear-gradient(135deg, var(--color-tag-bg) 0%, #faf5ff 100%);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  position: relative;
  font-style: italic;
}

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

/* Code blocks */
.entry-content pre {
  margin: 0 0 var(--spacing-lg);
  border-radius: var(--radius-lg);
  overflow-x: auto;
  position: relative;
  box-shadow: var(--shadow-md);
}

.entry-content pre[class*="language-"] {
  font-size: 0.875rem;
  line-height: 1.6;
  padding: var(--spacing-xl) var(--spacing-lg) var(--spacing-lg);
}

.entry-content pre[class*="language-"]::before {
  content: attr(data-lang);
  position: absolute;
  top: 0;
  right: var(--spacing-md);
  background: var(--gradient-primary);
  color: #fff;
  padding: 2px 12px;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  font-family: var(--font-sans);
}

.entry-content code {
  font-family: var(--font-mono);
}

.entry-content :not(pre) > code {
  background: linear-gradient(135deg, #f1f5f9, #ede9fe);
  padding: 0.15em 0.5em;
  border-radius: var(--radius-sm);
  font-size: 0.88em;
  color: #7c3aed;
  font-weight: 500;
}

/* Tables */
.entry-content table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  margin: 0 0 var(--spacing-lg);
  font-size: 0.9rem;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
}

.entry-content th,
.entry-content td {
  padding: var(--spacing-sm) var(--spacing-md);
  border-bottom: 1px solid var(--color-border);
  text-align: left;
}

.entry-content th {
  background: linear-gradient(135deg, #f8fafc, #f1f5f9);
  font-weight: 700;
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  letter-spacing: 0.03em;
}

.entry-content tr:last-child td {
  border-bottom: none;
}

.entry-content tbody tr:hover {
  background: var(--color-tag-bg);
}

/* Mermaid diagrams */
.mermaid {
  margin: var(--spacing-lg) 0;
  text-align: center;
  background: linear-gradient(135deg, #fafbff 0%, #f8fafc 100%);
  padding: var(--spacing-xl);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  overflow-x: auto;
  box-shadow: var(--shadow-sm);
}

/* Images in content */
.entry-content img {
  border-radius: var(--radius-md);
  margin: var(--spacing-lg) auto;
}

/* ---------- Entry Footer ---------- */
.entry-footer {
  margin-top: var(--spacing-2xl);
}

.entry-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-xl);
}

.tag-link {
  display: inline-block;
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 500;
  border: 1px solid transparent;
  transition: all var(--transition-base);
}

.tag-link:hover {
  background: var(--color-primary);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(37,99,235,0.3);
}

/* ---------- Cross-Platform CTA ---------- */
.cross-platform-cta {
  background: linear-gradient(135deg, #eff6ff 0%, #f5f3ff 50%, #ecfdf5 100%);
  border-radius: var(--radius-xl);
  padding: var(--spacing-xl) var(--spacing-xl) var(--spacing-lg);
  margin: var(--spacing-xl) 0;
  text-align: center;
  border: 1px solid rgba(37,99,235,0.1);
  position: relative;
  overflow: hidden;
}
.cross-platform-cta::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-primary);
}

.cta-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin: 0 0 var(--spacing-lg);
}

.cta-links {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.cta-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  border-radius: var(--radius-lg);
  font-weight: 600;
  font-size: 0.95rem;
  color: #fff;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.cta-link:hover {
  transform: translateY(-3px);
  color: #fff;
}

.cta-link--note   { background: linear-gradient(135deg, #41c9b4, #2db59f); }
.cta-link--note:hover { box-shadow: 0 8px 24px rgba(65,201,180,0.4); }
.cta-link--qiita  { background: linear-gradient(135deg, #55c500, #4bad00); }
.cta-link--qiita:hover { box-shadow: 0 8px 24px rgba(85,197,0,0.4); }
.cta-link--zenn   { background: linear-gradient(135deg, #3ea8ff, #2b90e0); }
.cta-link--zenn:hover { box-shadow: 0 8px 24px rgba(62,168,255,0.4); }

.cta-link__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: rgba(255,255,255,0.25);
  border-radius: 50%;
  font-size: 0.85rem;
  font-weight: 800;
}

/* ---------- Related Posts ---------- */
.related-posts {
  margin-top: var(--spacing-xl);
  padding-top: var(--spacing-xl);
  border-top: 1px solid var(--color-border);
}

.related-posts__title {
  font-size: 1.2rem;
  font-weight: 700;
  margin: 0 0 var(--spacing-lg);
}

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

.related-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: all var(--transition-base);
  border: 1px solid transparent;
}

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

.related-card__link {
  display: block;
  text-decoration: none;
  color: inherit;
}

.related-card__thumbnail {
  margin: 0;
  aspect-ratio: 16/9;
  overflow: hidden;
}

.related-card__thumbnail img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.related-card__title {
  font-size: 0.9rem;
  font-weight: 600;
  line-height: var(--line-height-heading);
  margin: 0;
  padding: var(--spacing-md) var(--spacing-md) var(--spacing-xs);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.related-card__date {
  display: block;
  font-size: 0.75rem;
  color: var(--color-text-secondary);
  padding: 0 var(--spacing-md) var(--spacing-md);
}

/* ---------- Pagination ---------- */
.pagination {
  margin-top: var(--spacing-xl);
}

.pagination .nav-links {
  display: flex;
  justify-content: center;
  gap: var(--spacing-sm);
}

.pagination .page-numbers {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 42px;
  height: 42px;
  padding: 0 var(--spacing-sm);
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  transition: all var(--transition-fast);
}
.pagination .page-numbers:hover {
  border-color: var(--color-primary-light);
  color: var(--color-primary);
  background: var(--color-tag-bg);
}

.pagination .page-numbers.current {
  background: var(--gradient-primary);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 4px 12px rgba(37,99,235,0.3);
}

/* ---------- Site Footer ---------- */
.site-footer {
  background: var(--color-footer-bg) url('../images/footer-pattern.svg') repeat;
  background-size: 600px 300px;
  color: var(--color-footer-text);
  margin-top: calc(var(--spacing-2xl) + 60px);
  position: relative;
}

.site-footer__wave {
  position: absolute;
  top: -59px;
  left: 0;
  right: 0;
  height: 60px;
  color: var(--color-footer-bg);
  line-height: 0;
}
.site-footer__wave svg {
  width: 100%;
  height: 100%;
}

.site-footer__inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: var(--spacing-2xl) var(--spacing-lg) var(--spacing-xl);
  text-align: center;
}

.footer-navigation ul {
  display: flex;
  justify-content: center;
  list-style: none;
  margin: 0 0 var(--spacing-md);
  padding: 0;
  gap: var(--spacing-lg);
}

.footer-navigation a {
  font-size: 0.85rem;
  color: var(--color-footer-text);
  transition: color var(--transition-fast);
}
.footer-navigation a:hover {
  color: #fff;
}

.site-footer__platforms {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-md);
}

.footer-platform-link {
  font-size: 0.85rem;
  font-weight: 500;
}

.site-footer__copy {
  font-size: 0.8rem;
  color: var(--color-footer-text);
  margin: 0;
}
.site-footer__copy a {
  color: #e2e8f0;
}
.site-footer__copy a:hover {
  color: #fff;
}

/* ---------- 404 ---------- */
.error-404 {
  text-align: center;
  padding: var(--spacing-2xl) 0;
}

.error-404__search {
  max-width: 400px;
  margin: var(--spacing-xl) auto;
}

.error-404__recent {
  margin-top: var(--spacing-xl);
  text-align: left;
  max-width: 400px;
  margin-left: auto;
  margin-right: auto;
}

/* ---------- Search Form ---------- */
.search-form {
  display: flex;
  gap: var(--spacing-sm);
}

.search-form .search-field {
  flex: 1;
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-family: var(--font-sans);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.search-form .search-field:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}

.search-form .search-submit {
  padding: var(--spacing-sm) var(--spacing-lg);
  background: var(--gradient-primary);
  color: #fff;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  font-weight: 600;
  transition: all var(--transition-fast);
  font-family: var(--font-sans);
}
.search-form .search-submit:hover {
  box-shadow: 0 4px 12px rgba(37,99,235,0.3);
  transform: translateY(-1px);
}

/* ---------- No Results ---------- */
.no-results {
  text-align: center;
  padding: var(--spacing-2xl) 0;
}

/* ---------- Skip Link ---------- */
.screen-reader-text {
  clip: rect(1px, 1px, 1px, 1px);
  position: absolute !important;
  height: 1px;
  width: 1px;
  overflow: hidden;
}
.screen-reader-text:focus {
  clip: auto !important;
  display: block;
  height: auto;
  width: auto;
  z-index: 9999;
  background: var(--color-surface);
  padding: var(--spacing-md);
}

/* ---------- Breadcrumb ---------- */
.breadcrumb {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: var(--spacing-md) var(--spacing-lg);
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}
.breadcrumb__list {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  flex-wrap: wrap;
  gap: 0;
}
.breadcrumb__item::after {
  content: ">";
  margin: 0 var(--spacing-sm);
  color: var(--color-border);
}
.breadcrumb__item:last-child::after { display: none; }
.breadcrumb__item--current { color: var(--color-text); }
.breadcrumb__item a { color: var(--color-text-secondary); }
.breadcrumb__item a:hover { color: var(--color-primary); }

/* ---------- Header Actions ---------- */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}
.search-toggle {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--spacing-sm) var(--spacing-md);
  cursor: pointer;
  color: var(--color-text-secondary);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  transition: all var(--transition-fast);
  font-size: 0.8rem;
  font-family: var(--font-sans);
}
.search-toggle::after {
  content: 'Ctrl+K';
  font-size: 0.65rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  padding: 1px 6px;
  border-radius: 4px;
  color: var(--color-text-secondary);
}
.search-toggle:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-tag-bg);
}

/* ---------- Search Modal ---------- */
.search-modal[hidden] {
  display: none !important;
}
.search-modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 10vh;
}
.search-modal__overlay {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.5);
  backdrop-filter: blur(4px);
}
.search-modal__content {
  position: relative;
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  width: 90%;
  max-width: 640px;
  max-height: 70vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  box-shadow: 0 24px 80px rgba(0,0,0,0.25), 0 0 0 1px rgba(255,255,255,0.1);
  animation: modal-in 0.2s ease-out;
}
@keyframes modal-in {
  from { opacity: 0; transform: scale(0.95) translateY(-10px); }
  to { opacity: 1; transform: scale(1) translateY(0); }
}
.search-modal__header {
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--color-border);
}
.search-form--modal {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  border: none;
}
.search-form--modal .search-field {
  flex: 1;
  border: none;
  outline: none;
  font-size: 1.1rem;
  padding: var(--spacing-sm) 0;
  background: transparent;
}
.search-modal__icon { color: var(--color-text-secondary); flex-shrink: 0; }
.search-modal__close {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-text-secondary);
  padding: var(--spacing-xs);
  flex-shrink: 0;
}
.search-modal__filters {
  display: flex;
  gap: var(--spacing-xs);
  margin-top: var(--spacing-md);
  flex-wrap: wrap;
}
.filter-tag {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  padding: 4px 12px;
  font-size: 0.8rem;
  cursor: pointer;
  transition: all 0.2s;
  color: var(--color-text-secondary);
}
.filter-tag:hover,
.filter-tag--active {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}
.search-modal__results {
  overflow-y: auto;
  padding: var(--spacing-lg);
  flex: 1;
}
.search-modal__hint {
  color: var(--color-text-secondary);
  text-align: center;
  margin: var(--spacing-lg) 0;
}
.search-modal__suggest h4 {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  margin: var(--spacing-lg) 0 var(--spacing-sm);
}
.search-modal__suggest ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.search-modal__suggest li { margin-bottom: var(--spacing-xs); }
.search-modal__suggest a {
  font-size: 0.9rem;
  display: block;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-sm);
}
.search-modal__suggest a:hover { background: var(--color-bg); }

.search-results-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.search-result-item { margin-bottom: var(--spacing-sm); }
.search-result-item__link {
  display: flex;
  gap: var(--spacing-md);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  color: inherit;
  text-decoration: none;
  transition: background 0.2s;
}
.search-result-item__link:hover { background: var(--color-bg); }
.search-result-item__thumb {
  width: 60px;
  height: 42px;
  border-radius: var(--radius-sm);
  object-fit: cover;
  flex-shrink: 0;
}
.search-result-item__body { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.search-result-item__cat {
  font-size: 0.7rem;
  color: var(--color-primary);
  font-weight: 600;
  text-transform: uppercase;
}
.search-result-item__title {
  font-size: 0.9rem;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.search-result-item__excerpt {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  display: -webkit-box;
  -webkit-line-clamp: 1;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.search-result-item__date { font-size: 0.75rem; color: var(--color-text-secondary); }
.search-no-result {
  text-align: center;
  color: var(--color-text-secondary);
  padding: var(--spacing-xl) 0;
}

/* ---------- Hero (Front Page) ---------- */
.front-page {
  /* ヒーロー＋ウェーブを全幅にするため親のmax-widthを打ち消す */
  margin-left: calc(-50vw + 50%);
  margin-right: calc(-50vw + 50%);
  width: 100vw;
}
.front-section__inner,
.hero__inner {
  max-width: var(--content-wide);
  margin: 0 auto;
}
.hero {
  background: var(--gradient-hero);
  color: #fff;
  text-align: center;
  padding: var(--spacing-3xl) var(--spacing-lg);
  position: relative;
  overflow: hidden;
}
.hero__pattern {
  position: absolute;
  inset: 0;
  background-image:
    url('../images/hero-pattern.svg'),
    radial-gradient(circle at 20% 50%, rgba(37,99,235,0.15) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(124,58,237,0.15) 0%, transparent 50%),
    radial-gradient(circle at 50% 80%, rgba(5,150,105,0.1) 0%, transparent 50%);
  background-size: cover, auto, auto, auto;
  background-position: center;
}
.hero__glow {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(37,99,235,0.12) 0%, transparent 70%);
  animation: hero-pulse 4s ease-in-out infinite alternate;
}
@keyframes hero-pulse {
  from { transform: translate(-50%, -50%) scale(1); opacity: 0.6; }
  to { transform: translate(-50%, -50%) scale(1.2); opacity: 1; }
}
.hero-wave {
  margin-top: -2px;
  line-height: 0;
  background: linear-gradient(135deg, #1e1b4b 0%, #1e3a5f 100%);
}
.hero-wave img {
  width: 100%;
  height: 80px;
  display: block;
}
.hero__inner {
  max-width: 700px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}
.hero__badge {
  display: inline-block;
  background: rgba(255,255,255,0.12);
  border: 1px solid rgba(255,255,255,0.2);
  padding: 4px 16px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: var(--spacing-lg);
  backdrop-filter: blur(4px);
}
.hero__title {
  font-size: 2.5rem;
  font-weight: 800;
  margin: 0 0 var(--spacing-md);
  line-height: var(--line-height-heading);
  letter-spacing: -0.02em;
  text-shadow: 0 2px 20px rgba(0,0,0,0.3);
}
.hero__description {
  font-size: 1.15rem;
  opacity: 0.85;
  margin: 0 0 var(--spacing-xl);
  line-height: 1.7;
}
.hero__search {
  position: relative;
  max-width: 520px;
  margin: 0 auto;
}
.search-form--hero {
  background: rgba(255,255,255,0.1);
  border-radius: var(--radius-xl);
  border: 1px solid rgba(255,255,255,0.2);
  backdrop-filter: blur(12px);
  transition: all var(--transition-base);
}
.search-form--hero:focus-within {
  background: rgba(255,255,255,0.18);
  border-color: rgba(255,255,255,0.4);
  box-shadow: 0 0 30px rgba(37,99,235,0.2);
}
.search-form--hero .search-field {
  background: transparent;
  border: none;
  color: #fff;
  font-size: 1rem;
  padding: var(--spacing-md);
}
.search-form--hero .search-field::placeholder { color: rgba(255,255,255,0.6); }
.search-form--hero .search-submit {
  background: rgba(255,255,255,0.2);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  padding: var(--spacing-sm) var(--spacing-lg);
  cursor: pointer;
  margin: var(--spacing-xs);
}
.search-results-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--color-surface);
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  box-shadow: var(--shadow-md);
  z-index: 10;
  max-height: 300px;
  overflow-y: auto;
}
.hero-result-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) var(--spacing-md);
  color: var(--color-text);
  text-decoration: none;
  font-size: 0.9rem;
  border-bottom: 1px solid var(--color-border);
}
.hero-result-item:hover { background: var(--color-bg); }
.hero-result-item__title { font-weight: 500; }
.hero-result-item__cat {
  font-size: 0.75rem;
  color: var(--color-primary);
  background: var(--color-tag-bg);
  padding: 2px 8px;
  border-radius: 10px;
  flex-shrink: 0;
}

/* ---------- Front Page 2-Column Layout ---------- */
.front-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: var(--spacing-xl);
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: var(--spacing-xl) var(--spacing-lg);
}

/* ---------- Front Page Sections ---------- */
.front-section {
  padding: 0 0 var(--spacing-2xl);
}
.front-section__inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}
/* front-layout 内ではinnerのmax-widthとpaddingは不要 */
.front-layout .front-section__inner,
.front-layout .front-section {
  padding-left: 0;
  padding-right: 0;
}
.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-xl);
}
.section-title {
  font-size: 1.5rem;
  font-weight: 800;
  margin: 0;
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}
.section-title__icon {
  font-size: 1.2rem;
}
.section-more {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-primary);
  display: flex;
  align-items: center;
  gap: 4px;
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}
.section-more:hover {
  background: var(--color-tag-bg);
  color: var(--color-primary-hover);
}
.front-section--popular {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  position: relative;
}

/* Post Grid (Home 2-col) */
.post-grid--home {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-lg);
}
.post-grid--home .post-card__link {
  flex-direction: column;
}
.post-grid--home .post-card__thumbnail {
  width: 100%;
  aspect-ratio: 16/9;
}

/* Post Grid (Featured) */
.post-grid--featured {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-lg);
}
.post-grid--featured .post-card--large {
  grid-column: 1 / -1;
}
.post-card--large .post-card__link {
  flex-direction: row;
}
.post-card--large .post-card__thumbnail {
  width: 55%;
  aspect-ratio: 16/9;
}
.post-card--large .post-card__title { font-size: 1.35rem; letter-spacing: -0.01em; }
.post-grid--featured .post-card:not(.post-card--large) .post-card__link {
  flex-direction: column;
}
.post-grid--featured .post-card:not(.post-card--large) .post-card__thumbnail {
  width: 100%;
  aspect-ratio: 16/9;
}
.post-card__meta {
  display: flex;
  gap: var(--spacing-md);
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin-top: auto;
}
.post-card__reading-time,
.entry-reading-time,
.entry-views {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
}
.post-card__thumbnail--placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  background: url('../images/placeholder-article.svg') center/cover no-repeat;
  aspect-ratio: 16/9;
  font-size: 2.5rem;
  position: relative;
  overflow: hidden;
}
.post-card__thumbnail--placeholder::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent 40%, rgba(255,255,255,0.1) 50%, transparent 60%);
  animation: shimmer 4s ease-in-out infinite;
}
@keyframes shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}
.placeholder-icon { display: none; }
.post-card:nth-child(2) .post-card__thumbnail--placeholder {
  background-image: url('../images/placeholder-tech.svg');
}
.post-card:nth-child(3) .post-card__thumbnail--placeholder {
  background-image: url('../images/placeholder-ai.svg');
}

/* Popular Posts (Front Page) */
.popular-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}
.popular-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-md) var(--spacing-lg);
  background: var(--color-bg);
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
  border: 1px solid transparent;
}
.popular-item:hover {
  box-shadow: var(--shadow-md);
  background: #fff;
  border-color: var(--color-primary-light);
  transform: translateX(4px);
}
.popular-item__rank {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  font-weight: 800;
  font-size: 1rem;
  background: var(--color-border);
  color: var(--color-text-secondary);
}
.popular-item:nth-child(1) .popular-item__rank { background: #ffd700; color: #1a1a2e; }
.popular-item:nth-child(2) .popular-item__rank { background: #c0c0c0; color: #1a1a2e; }
.popular-item:nth-child(3) .popular-item__rank { background: #cd7f32; color: #fff; }
.popular-item__link {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  flex: 1;
  text-decoration: none;
  color: inherit;
}
.popular-item__thumbnail { margin: 0; flex-shrink: 0; }
.popular-item__thumbnail img {
  width: 80px;
  height: 54px;
  object-fit: cover;
  border-radius: var(--radius-sm);
}
.popular-item__body { flex: 1; min-width: 0; }
.popular-item__category {
  font-size: 0.7rem;
  color: var(--color-primary);
  font-weight: 600;
  text-transform: uppercase;
}
.popular-item__title {
  font-size: 0.95rem;
  font-weight: 600;
  margin: 2px 0;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.popular-item__meta {
  display: flex;
  gap: var(--spacing-md);
  font-size: 0.75rem;
  color: var(--color-text-secondary);
}

/* Category Grid */
.category-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-md);
}
.category-card {
  display: block;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl) var(--spacing-lg);
  text-decoration: none;
  color: inherit;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}
.category-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-primary);
  transform: scaleX(0);
  transition: transform var(--transition-base);
  transform-origin: left;
}
.category-card::after {
  content: '';
  position: absolute;
  right: -10px;
  bottom: -10px;
  width: 80px;
  height: 80px;
  background: var(--gradient-primary);
  opacity: 0.05;
  border-radius: 50%;
  transition: all var(--transition-slow);
}
.category-card:hover::after {
  opacity: 0.1;
  transform: scale(1.4);
}
.category-card:hover {
  border-color: var(--color-primary-light);
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}
.category-card:hover::before {
  transform: scaleX(1);
}
.category-card__name {
  font-size: 1.1rem;
  font-weight: 700;
  margin: 0 0 var(--spacing-xs);
}
.category-card__count {
  font-size: 0.8rem;
  color: #fff;
  font-weight: 700;
  margin: 0;
  display: inline-block;
  background: var(--gradient-primary);
  padding: 2px 10px;
  border-radius: 12px;
}
.category-card__desc {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin: var(--spacing-sm) 0 0;
  line-height: 1.5;
}

/* ---------- Single Post Layout (Content + Sidebar) ---------- */
.single-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: var(--spacing-xl);
  max-width: var(--content-wide);
  margin: 0 auto;
}
.single-layout .single-post {
  min-width: 0;
  max-width: none;
}

/* ---------- Share Sidebar ---------- */
.share-sidebar {
  position: fixed;
  top: 50%;
  left: max(calc((100vw - var(--content-wide)) / 2 - 60px), 12px);
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  z-index: 10;
}
.share-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  color: var(--color-text-secondary);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
  box-shadow: var(--shadow-sm);
}
.share-btn:hover { color: #fff; }
.share-btn--x:hover { background: #000; border-color: #000; }
.share-btn--fb:hover { background: #1877f2; border-color: #1877f2; }
.share-btn--hatena:hover { background: #00a4de; border-color: #00a4de; }
.share-btn--copy:hover { background: var(--color-accent); border-color: var(--color-accent); }
.share-btn--copy.is-copied {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: #fff;
}

/* Share Inline */
.share-inline {
  margin: var(--spacing-xl) 0;
  padding: var(--spacing-xl);
  background: linear-gradient(135deg, #f8fafc 0%, #eff6ff 100%);
  border-radius: var(--radius-xl);
  text-align: center;
  border: 1px solid var(--color-border);
}
.share-inline__title {
  font-size: 1rem;
  font-weight: 600;
  margin: 0 0 var(--spacing-md);
}
.share-inline__buttons {
  display: flex;
  justify-content: center;
  gap: var(--spacing-sm);
}
.share-btn-inline {
  display: inline-block;
  padding: var(--spacing-sm) var(--spacing-xl);
  border-radius: var(--radius-lg);
  font-weight: 600;
  font-size: 0.85rem;
  color: #fff;
  text-decoration: none;
  transition: all var(--transition-base);
}
.share-btn-inline:hover { color: #fff; transform: translateY(-2px); }
.share-btn-inline--x { background: linear-gradient(135deg, #333, #000); }
.share-btn-inline--x:hover { box-shadow: 0 6px 20px rgba(0,0,0,0.3); }
.share-btn-inline--fb { background: linear-gradient(135deg, #1877f2, #0d65d9); }
.share-btn-inline--fb:hover { box-shadow: 0 6px 20px rgba(24,119,242,0.4); }
.share-btn-inline--hatena { background: linear-gradient(135deg, #00a4de, #008ec4); }
.share-btn-inline--hatena:hover { box-shadow: 0 6px 20px rgba(0,164,222,0.4); }

/* ---------- Author Box ---------- */
.author-box {
  display: flex;
  gap: var(--spacing-lg);
  padding: var(--spacing-xl);
  background: linear-gradient(135deg, #fafbff 0%, #f8fafc 100%);
  border-radius: var(--radius-xl);
  margin: var(--spacing-xl) 0;
  border: 1px solid var(--color-border);
  position: relative;
  overflow: hidden;
}
.author-box::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-accent);
}
.author-box__avatar img {
  border-radius: 50%;
  width: 80px;
  height: 80px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  border: 3px solid #fff;
}
.author-box__label {
  font-size: 0.75rem;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  font-weight: 600;
  margin: 0 0 var(--spacing-xs);
}
.author-box__name {
  font-size: 1.1rem;
  font-weight: 700;
  margin: 0 0 var(--spacing-sm);
}
.author-box__name a { color: inherit; }
.author-box__bio {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin: 0;
  line-height: 1.6;
}

/* ---------- Post Navigation ---------- */
.post-navigation {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-md);
  margin: var(--spacing-xl) 0;
}
.post-nav-link {
  display: block;
  padding: var(--spacing-lg);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: inherit;
  transition: all var(--transition-base);
}
.post-nav-link:hover {
  border-color: var(--color-primary-light);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.post-nav-link--next { text-align: right; }
.post-nav-link__label {
  display: block;
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xs);
}
.post-nav-link__title {
  display: block;
  font-weight: 600;
  font-size: 0.9rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ---------- Sidebar ---------- */
.sidebar {
  position: sticky;
  top: 80px;
  align-self: start;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--color-border) transparent;
}
.sidebar::-webkit-scrollbar { width: 4px; }
.sidebar::-webkit-scrollbar-track { background: transparent; }
.sidebar::-webkit-scrollbar-thumb { background: var(--color-border); border-radius: 4px; }
.sidebar-section {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
  transition: box-shadow var(--transition-slow);
}
.sidebar-section:hover {
  box-shadow: var(--shadow-sm);
}
.sidebar-section__title {
  font-size: 0.95rem;
  font-weight: 700;
  margin: 0 0 var(--spacing-md);
  padding-bottom: var(--spacing-sm);
  border-bottom: 2px solid transparent;
  border-image: var(--gradient-primary) 1;
}

/* Sidebar Post List */
.sidebar-post-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.sidebar-post-list--ranked { counter-reset: rank; }
.sidebar-post-list--ranked .sidebar-post-item { counter-increment: rank; }
.sidebar-post-list--ranked .sidebar-post-item::before {
  content: counter(rank);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--color-border);
  color: var(--color-text-secondary);
  font-size: 0.75rem;
  font-weight: 700;
  flex-shrink: 0;
}
.sidebar-post-list--ranked .sidebar-post-item:nth-child(1)::before { background: #ffd700; color: #1a1a2e; }
.sidebar-post-list--ranked .sidebar-post-item:nth-child(2)::before { background: #c0c0c0; color: #1a1a2e; }
.sidebar-post-list--ranked .sidebar-post-item:nth-child(3)::before { background: #cd7f32; color: #fff; }

.sidebar-post-item {
  display: flex;
  gap: var(--spacing-sm);
  align-items: center;
  padding: var(--spacing-sm) 0;
  border-bottom: 1px solid var(--color-border);
}
.sidebar-post-item:last-child { border-bottom: none; }
.sidebar-post-item__link {
  display: flex;
  gap: var(--spacing-sm);
  align-items: center;
  text-decoration: none;
  color: inherit;
  flex: 1;
  min-width: 0;
}
.sidebar-post-item__thumb { margin: 0; flex-shrink: 0; }
.sidebar-post-item__thumb img {
  width: 60px;
  height: 40px;
  object-fit: cover;
  border-radius: var(--radius-sm);
}
.sidebar-post-item__body {
  display: flex;
  flex-direction: column;
  min-width: 0;
}
.sidebar-post-item__title {
  font-size: 0.8rem;
  font-weight: 600;
  line-height: 1.3;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.sidebar-post-item__date,
.sidebar-post-item__views {
  font-size: 0.7rem;
  color: var(--color-text-secondary);
}

/* Sidebar Likes ranking */
.sidebar-post-item__likes {
  font-size: 0.7rem;
  color: #f43f5e;
}
.sidebar-post-list--likes .sidebar-post-item:nth-child(1)::before { background: linear-gradient(135deg, #f43f5e, #ec4899); color: #fff; }
.sidebar-post-list--likes .sidebar-post-item:nth-child(2)::before { background: #fda4af; color: #fff; }
.sidebar-post-list--likes .sidebar-post-item:nth-child(3)::before { background: #fecdd3; color: #9f1239; }

/* Sidebar Categories */
.sidebar-category-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.sidebar-category-link {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) 0;
  border-bottom: 1px solid var(--color-border);
  text-decoration: none;
  color: inherit;
  font-size: 0.85rem;
}
.sidebar-category-link:last-child { border-bottom: none; }
.sidebar-category-link:hover { color: var(--color-primary); }
.sidebar-category-link__count {
  background: var(--color-bg);
  padding: 2px 8px;
  border-radius: 10px;
  font-size: 0.75rem;
  color: var(--color-text-secondary);
}

/* Sidebar Tags */
.sidebar-tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
}
.sidebar-tag {
  display: inline-block;
  background: var(--color-bg);
  color: var(--color-text-secondary);
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.75rem;
  text-decoration: none;
  transition: all var(--transition-base);
  border: 1px solid transparent;
}
.sidebar-tag:hover {
  background: var(--color-primary);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 2px 8px rgba(37,99,235,0.3);
}

/* ---------- WordPress Default Widgets (sidebar) ---------- */
.sidebar-widgets .widget {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}
.sidebar-widgets h3.widget-title {
  font-size: 0.95rem;
  font-weight: 700;
  margin: 0 0 var(--spacing-md);
  padding-bottom: var(--spacing-sm);
  border-width: 0 0 2px 0;
  border-style: solid;
  border-color: transparent;
  border-image: var(--gradient-primary) 1;
}
.sidebar-widgets .widget ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.sidebar-widgets .widget li {
  padding: var(--spacing-sm) 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.85rem;
}
.sidebar-widgets .widget li:last-child {
  border-bottom: none;
}
.sidebar-widgets .widget a {
  color: var(--color-text);
  text-decoration: none;
}
.sidebar-widgets .widget a:hover {
  color: var(--color-primary);
}

/* ---------- Footer Widgets ---------- */
.footer-widgets {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--spacing-xl);
  text-align: left;
  margin-bottom: var(--spacing-xl);
  padding-bottom: var(--spacing-xl);
  border-bottom: 1px solid rgba(148,163,184,0.2);
}
.footer-widgets__title {
  font-size: 1.1rem;
  font-weight: 700;
  margin: 0 0 var(--spacing-sm);
  color: #e2e8f0;
}
.footer-widgets__desc {
  font-size: 0.85rem;
  color: var(--color-footer-text);
  margin: 0 0 var(--spacing-md);
}
.footer-platforms {
  display: flex;
  gap: var(--spacing-sm);
}
.footer-platform-badge {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  font-weight: 800;
  font-size: 0.85rem;
  color: #fff;
  text-decoration: none;
  transition: all var(--transition-base);
}
.footer-platform-badge:hover {
  transform: scale(1.15) translateY(-2px);
  color: #fff;
}
.footer-platform-badge--note { background: linear-gradient(135deg, #41c9b4, #2db59f); }
.footer-platform-badge--note:hover { box-shadow: 0 4px 16px rgba(65,201,180,0.5); }
.footer-platform-badge--qiita { background: linear-gradient(135deg, #55c500, #4bad00); }
.footer-platform-badge--qiita:hover { box-shadow: 0 4px 16px rgba(85,197,0,0.5); }
.footer-platform-badge--zenn { background: linear-gradient(135deg, #3ea8ff, #2b90e0); }
.footer-platform-badge--zenn:hover { box-shadow: 0 4px 16px rgba(62,168,255,0.5); }

/* ==========================================================================
   Shortcodes
   ========================================================================== */

/* ---------- Callout Boxes: [note], [warning], [tip], [info] ---------- */
.sc-callout {
  margin: var(--spacing-lg) 0;
  border-radius: var(--radius-md);
  border: 1px solid;
  overflow: hidden;
}
.sc-callout__header {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-lg);
  font-weight: 700;
  font-size: 0.9rem;
}
.sc-callout__icon {
  font-size: 1.1rem;
  line-height: 1;
}
.sc-callout__body {
  padding: var(--spacing-md) var(--spacing-lg) var(--spacing-lg);
  font-size: 0.95rem;
  line-height: 1.8;
}
.sc-callout__body p:last-child { margin-bottom: 0; }

.sc-callout--note {
  border-color: #dbeafe;
  background: #eff6ff;
}
.sc-callout--note .sc-callout__header {
  background: #dbeafe;
  color: #1e40af;
}
.sc-callout--warning {
  border-color: #fde68a;
  background: #fffbeb;
}
.sc-callout--warning .sc-callout__header {
  background: #fef3c7;
  color: #92400e;
}
.sc-callout--tip {
  border-color: #a7f3d0;
  background: #ecfdf5;
}
.sc-callout--tip .sc-callout__header {
  background: #d1fae5;
  color: #065f46;
}
.sc-callout--info {
  border-color: #e9d5ff;
  background: #faf5ff;
}
.sc-callout--info .sc-callout__header {
  background: #f3e8ff;
  color: #6b21a8;
}

/* ---------- Timeline: [timeline] + [timeline_item] ---------- */
.sc-timeline {
  position: relative;
  padding-left: 32px;
  margin: var(--spacing-xl) 0;
}
.sc-timeline::before {
  content: '';
  position: absolute;
  left: 11px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--gradient-primary);
  border-radius: 1px;
}
.sc-timeline__item {
  position: relative;
  padding-bottom: var(--spacing-xl);
}
.sc-timeline__item:last-child {
  padding-bottom: 0;
}
.sc-timeline__marker {
  position: absolute;
  left: -32px;
  top: 2px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--color-surface);
  border: 3px solid var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1;
}
.sc-timeline__icon {
  font-size: 0.7rem;
  line-height: 1;
}
.sc-timeline__date {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-primary);
  background: var(--color-tag-bg);
  padding: 2px 10px;
  border-radius: 10px;
  margin-bottom: var(--spacing-xs);
}
.sc-timeline__title {
  font-size: 1.05rem;
  font-weight: 700;
  margin: var(--spacing-xs) 0 var(--spacing-sm);
}
.sc-timeline__body {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}
.sc-timeline__body p:last-child { margin-bottom: 0; }

/* ---------- Steps: [steps] + [step] ---------- */
.sc-steps {
  counter-reset: step;
  margin: var(--spacing-xl) 0;
}
.sc-step {
  counter-increment: step;
  display: flex;
  gap: var(--spacing-lg);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: box-shadow var(--transition-base);
}
.sc-step:hover {
  box-shadow: var(--shadow-sm);
}
.sc-step__number {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--gradient-primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1rem;
}
.sc-step__number::before {
  content: counter(step);
}
.sc-step__content {
  flex: 1;
  min-width: 0;
}
.sc-step__title {
  font-size: 1.05rem;
  font-weight: 700;
  margin: 0 0 var(--spacing-sm);
}
.sc-step__body {
  font-size: 0.95rem;
  line-height: 1.7;
}
.sc-step__body p:last-child { margin-bottom: 0; }

/* ---------- Link Card: [link_card] ---------- */
.sc-link-card {
  display: flex;
  align-items: stretch;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  margin: var(--spacing-lg) 0;
  transition: all var(--transition-base);
}
.sc-link-card:hover {
  border-color: var(--color-primary-light);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.sc-link-card__body {
  flex: 1;
  padding: var(--spacing-lg);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  min-width: 0;
}
.sc-link-card__title {
  font-weight: 700;
  font-size: 0.95rem;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.sc-link-card__desc {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.sc-link-card__domain {
  font-size: 0.75rem;
  color: var(--color-text-secondary);
  margin-top: auto;
}
.sc-link-card__domain::before {
  content: '🔗 ';
}
.sc-link-card__thumb {
  flex-shrink: 0;
  width: 160px;
  margin: 0;
}
.sc-link-card__thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- Amazon Card: [amazon] ---------- */
.sc-amazon {
  display: flex;
  gap: var(--spacing-lg);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  margin: var(--spacing-lg) 0;
  position: relative;
  overflow: hidden;
}
.sc-amazon::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #ff9900, #ffb84d);
}
.sc-amazon__image {
  flex-shrink: 0;
  width: 120px;
  margin: 0;
}
.sc-amazon__image img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
}
.sc-amazon__body {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  min-width: 0;
}
.sc-amazon__badge {
  display: inline-block;
  background: #ff9900;
  color: #fff;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 4px;
  width: fit-content;
}
.sc-amazon__title {
  font-weight: 700;
  font-size: 1rem;
  color: var(--color-text);
  text-decoration: none;
  line-height: 1.4;
}
.sc-amazon__title:hover {
  color: var(--color-primary);
}
.sc-amazon__price {
  font-size: 1.1rem;
  font-weight: 800;
  color: #b12704;
}
.sc-amazon__btn {
  display: inline-block;
  background: linear-gradient(180deg, #f7dfa5, #f0c14b);
  border: 1px solid #a88734;
  border-radius: var(--radius-sm);
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: 0.85rem;
  font-weight: 600;
  color: #111;
  text-decoration: none;
  text-align: center;
  width: fit-content;
  transition: all var(--transition-fast);
}
.sc-amazon__btn:hover {
  background: linear-gradient(180deg, #f5d78e, #eeb933);
  color: #111;
}

/* ---------- Badge: [badge] ---------- */
.sc-badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}
.sc-badge--primary {
  background: var(--color-tag-bg);
  color: var(--color-primary);
}
.sc-badge--accent {
  background: var(--color-accent-light);
  color: var(--color-accent);
}
.sc-badge--warning {
  background: #fef3c7;
  color: #92400e;
}
.sc-badge--danger {
  background: #fee2e2;
  color: #991b1b;
}

/* ---------- Quote Box: [quote] ---------- */
.sc-quote {
  margin: var(--spacing-xl) 0;
  padding: 0;
}
.sc-quote__text {
  margin: 0;
  padding: var(--spacing-xl) var(--spacing-xl) var(--spacing-lg);
  background: linear-gradient(135deg, #f8fafc 0%, #eff6ff 100%);
  border-left: 4px solid transparent;
  border-image: var(--gradient-primary) 1;
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
  font-style: italic;
  font-size: 1.05rem;
  line-height: 1.8;
  position: relative;
}
.sc-quote__text::before {
  content: '\201C';
  position: absolute;
  top: var(--spacing-sm);
  left: var(--spacing-md);
  font-size: 3rem;
  color: var(--color-primary);
  opacity: 0.2;
  font-family: Georgia, serif;
  line-height: 1;
}
.sc-quote__text p:last-child { margin-bottom: 0; }
.sc-quote__cite {
  display: flex;
  gap: var(--spacing-sm);
  align-items: center;
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: 0.85rem;
  color: var(--color-text-secondary);
}
.sc-quote__cite::before {
  content: '—';
}
.sc-quote__author {
  font-weight: 600;
}
.sc-quote__cite cite {
  font-style: normal;
}
.sc-quote__cite a {
  color: var(--color-primary);
}

/* ---------- Accordion: [accordion] + [accordion_item] ---------- */
.sc-accordion {
  margin: var(--spacing-lg) 0;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}
.sc-accordion__item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: box-shadow var(--transition-base);
}
.sc-accordion__item[open] {
  box-shadow: var(--shadow-sm);
}
.sc-accordion__header {
  padding: var(--spacing-md) var(--spacing-lg);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: background var(--transition-fast);
}
.sc-accordion__header::-webkit-details-marker {
  display: none;
}
.sc-accordion__header::after {
  content: '+';
  font-size: 1.2rem;
  font-weight: 300;
  color: var(--color-text-secondary);
  transition: transform var(--transition-fast);
}
.sc-accordion__item[open] .sc-accordion__header::after {
  content: '−';
}
.sc-accordion__header:hover {
  background: var(--color-bg);
}
.sc-accordion__body {
  padding: 0 var(--spacing-lg) var(--spacing-lg);
  font-size: 0.95rem;
  line-height: 1.7;
}
.sc-accordion__body p:last-child { margin-bottom: 0; }

/* ---------- Columns: [columns] + [column] ---------- */
.sc-columns {
  display: grid;
  gap: var(--spacing-lg);
  margin: var(--spacing-lg) 0;
}
.sc-columns--2 { grid-template-columns: repeat(2, 1fr); }
.sc-columns--3 { grid-template-columns: repeat(3, 1fr); }
.sc-columns--4 { grid-template-columns: repeat(4, 1fr); }
.sc-column {
  min-width: 0;
}

/* ---------- Comparison: [comparison] ---------- */
.sc-comparison {
  margin: var(--spacing-lg) 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.sc-comparison__header {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  background: linear-gradient(135deg, #f8fafc, #f1f5f9);
  font-weight: 700;
  font-size: 1rem;
}
.sc-comparison__col {
  padding: var(--spacing-md) var(--spacing-lg);
  text-align: center;
}
.sc-comparison__col--vs {
  padding: var(--spacing-md) var(--spacing-sm);
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  font-weight: 600;
}
.sc-comparison__col--a { color: var(--color-primary); }
.sc-comparison__col--b { color: var(--color-accent); }
.sc-comparison__body {
  padding: var(--spacing-lg);
}
.sc-comparison__body table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
}

/* ==========================================================================
   Like Button
   ========================================================================== */
.like-button-wrap {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  margin: var(--spacing-xl) 0;
  justify-content: center;
}
.like-button {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  border-radius: var(--radius-xl);
  border: 2px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text-secondary);
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}
.like-button:hover {
  border-color: #f43f5e;
  color: #f43f5e;
  background: #fff1f2;
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(244,63,94,0.15);
}
.like-button.is-liked {
  border-color: #f43f5e;
  color: #f43f5e;
  background: linear-gradient(135deg, #fff1f2 0%, #fce7f3 100%);
}
.like-button.is-liked:hover {
  background: #ffe4e6;
}
.like-button.is-loading {
  opacity: 0.6;
  pointer-events: none;
}
.like-button__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  width: 24px;
  height: 24px;
}
.like-icon--outline,
.like-icon--filled {
  position: absolute;
  transition: all var(--transition-base);
}
.like-icon--filled {
  opacity: 0;
  transform: scale(0.5);
}
.like-button.is-liked .like-icon--outline {
  opacity: 0;
  transform: scale(0.5);
}
.like-button.is-liked .like-icon--filled {
  opacity: 1;
  transform: scale(1);
}
.like-button.is-animating .like-icon--filled {
  animation: like-pop 0.6s ease-out;
}
@keyframes like-pop {
  0% { transform: scale(0.5); }
  50% { transform: scale(1.3); }
  100% { transform: scale(1); }
}
.like-count {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-text-secondary);
  min-width: 20px;
}
.like-button.is-liked ~ .like-count {
  color: #f43f5e;
}

/* ---------- Marker (Highlight): [marker] ---------- */
.sc-marker {
  background: none;
  padding: 0 2px;
  border-radius: 2px;
}
.sc-marker--yellow {
  background: linear-gradient(transparent 60%, #fef08a 60%);
}
.sc-marker--blue {
  background: linear-gradient(transparent 60%, #bfdbfe 60%);
}
.sc-marker--pink {
  background: linear-gradient(transparent 60%, #fbcfe8 60%);
}
.sc-marker--green {
  background: linear-gradient(transparent 60%, #bbf7d0 60%);
}

/* ---------- Responsive ---------- */
@media (max-width: 1280px) {
  .share-sidebar { display: none; }
}

@media (max-width: 768px) {
  :root {
    --font-size-base: 0.95rem;
  }

  .menu-toggle {
    display: flex;
  }

  .main-navigation {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
  }

  .main-navigation.is-open {
    display: block;
  }

  .main-navigation ul {
    flex-direction: column;
    padding: var(--spacing-md) var(--spacing-lg);
    gap: 0;
  }

  .main-navigation li {
    border-bottom: 1px solid var(--color-border);
  }

  .main-navigation a {
    display: block;
    padding: var(--spacing-md) 0;
  }

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

  .entry-content h2 {
    font-size: 1.3rem;
  }

  .entry-content h3 {
    font-size: 1.1rem;
  }

  .post-card__link {
    flex-direction: column;
  }

  .post-card__thumbnail {
    width: 100%;
    aspect-ratio: 16/9;
  }

  .related-posts__list {
    grid-template-columns: 1fr;
  }

  .cta-links {
    flex-direction: column;
    align-items: center;
  }

  .cta-link {
    width: 100%;
    max-width: 280px;
    justify-content: center;
  }

  /* コードブロックのスクロール */
  .entry-content pre[class*="language-"] {
    font-size: 0.8rem;
  }

  /* Single layout & Front layout */
  .single-layout,
  .front-layout {
    grid-template-columns: 1fr;
  }
  .sidebar { position: static; max-height: none; overflow-y: visible; }

  /* Share sidebar hidden on smaller screens */
  .share-sidebar { display: none; }

  .sidebar { position: static; margin-top: var(--spacing-xl); }

  /* Post grid */
  .post-grid--featured { grid-template-columns: 1fr; }
  .post-grid--home { grid-template-columns: 1fr; }
  .post-card--large .post-card__link { flex-direction: column; }
  .post-card--large .post-card__thumbnail { width: 100%; }

  /* Category grid */
  .category-grid { grid-template-columns: 1fr 1fr; }

  /* Post navigation */
  .post-navigation { grid-template-columns: 1fr; }

  /* Author box */
  .author-box { flex-direction: column; align-items: center; text-align: center; }

  /* Footer widgets */
  .footer-widgets { grid-template-columns: 1fr; text-align: center; }
  .footer-platforms { justify-content: center; }

  /* Hero */
  .hero { padding: var(--spacing-xl) var(--spacing-md); }
  .hero__title { font-size: 1.6rem; }
  .hero__glow { width: 300px; height: 300px; }

  /* Shortcodes responsive */
  .sc-columns--2,
  .sc-columns--3,
  .sc-columns--4 { grid-template-columns: 1fr; }
  .sc-amazon { flex-direction: column; }
  .sc-amazon__image { width: 100%; max-width: 200px; margin: 0 auto; }
  .sc-link-card { flex-direction: column; }
  .sc-link-card__thumb { width: 100%; height: 160px; }

  /* Search toggle shortcut hint */
  .search-toggle::after { display: none; }

  /* Back to top */
  .back-to-top { bottom: 1rem; right: 1rem; width: 40px; height: 40px; }
}

@media (max-width: 480px) {
  .site-header__inner {
    padding: var(--spacing-sm) var(--spacing-md);
  }

  .site-main {
    padding: var(--spacing-lg) var(--spacing-md);
  }

  .category-grid { grid-template-columns: 1fr; }
}