/* blog.css - Notion Design System for decentralized-social */

/* ========================================
   Notion Design System
   - フォント：Inter (Google Fonts)
   - 色：Warm White (#f6f5f4), Near-Black (rgba(0,0,0,0.95)), Notion Blue (#0075de)
   - ボーダー：1px solid rgba(0,0,0,0.1) (whisper border)
   - シャドウ：4-5 層の低不透明度スタック
   - 余白：8px ベース、64-120px の generous vertical rhythm
   ======================================== */

/* Google Fonts - Inter + Noto Sans JP */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=Noto+Sans+JP:wght@400;500;600;700;800&display=swap');

/* CSS Variables */
:root {
  /* Colors */
  --notion-bg: #f6f5f4;
  --notion-surface: #ffffff;
  --notion-text-primary: rgba(0, 0, 0, 0.95);
  --notion-text-secondary: rgba(0, 0, 0, 0.65);
  --notion-text-tertiary: rgba(0, 0, 0, 0.45);
  --notion-blue: #0075de;
  --notion-blue-hover: #005fb8;
  --notion-border: rgba(0, 0, 0, 0.1);
  --notion-border-hover: rgba(0, 0, 0, 0.2);
  
  /* Shadows - 4-5 layer low opacity stack */
  --notion-shadow: 
    0 1px 2px rgba(0, 0, 0, 0.04),
    0 2px 4px rgba(0, 0, 0, 0.04),
    0 4px 8px rgba(0, 0, 0, 0.04),
    0 8px 16px rgba(0, 0, 0, 0.04),
    0 16px 32px rgba(0, 0, 0, 0.04);
  --notion-shadow-hover:
    0 2px 4px rgba(0, 0, 0, 0.06),
    0 4px 8px rgba(0, 0, 0, 0.06),
    0 8px 16px rgba(0, 0, 0, 0.06),
    0 16px 32px rgba(0, 0, 0, 0.06),
    0 32px 64px rgba(0, 0, 0, 0.06);
  
  /* Spacing */
  --spacing-base: 8px;
  --spacing-sm: 16px;
  --spacing-md: 24px;
  --spacing-lg: 32px;
  --spacing-xl: 48px;
  --spacing-xxl: 64px;
  
  /* Layout */
  --max-width: 1200px;
  --content-width: 720px;
  --sidebar-width: 300px;
  --header-height: 64px;
  
  /* Typography */
  --font-family: 'Inter', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', 'Yu Gothic Medium', 'Meiryo', sans-serif;
  --font-size-base: 16px;
  --line-height-base: 1.6;
  
  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
}

/* ========================================
   Base Styles
   ======================================== */
body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: var(--line-height-base);
  color: var(--notion-text-primary);
  background-color: var(--notion-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* スキップリンク */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--notion-blue);
  color: #ffffff;
  padding: 8px 16px;
  z-index: 1001;
  font-weight: 600;
  transition: top 0.2s;
}

.skip-link:focus {
  top: 0;
}

/* ========================================
   Header Styles (matches main index.html)
   ======================================== */
.header {
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(12px);
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  transition: all 0.3s ease;
  border-bottom: 1px solid var(--notion-border);
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 0;
}

.logo h1 {
  font-size: 1.4rem;
  color: var(--notion-blue);
  margin: 0;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.logo a {
  color: var(--notion-blue);
}

.nav {
  display: flex;
  gap: 1.2rem;
  align-items: center;
  flex-wrap: wrap;
  max-width: 900px;
  justify-content: center;
}

.nav a {
  color: var(--notion-text-primary);
  font-weight: 500;
  position: relative;
  padding: 0.4rem 0.8rem;
  border-radius: var(--radius-sm);
  transition: all 0.2s ease;
  font-size: 0.9rem;
  white-space: nowrap;
}

.nav a:hover,
.nav a.active {
  color: var(--notion-blue);
  background: rgba(0, 117, 222, 0.08);
}

.hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  flex-direction: column;
  gap: 5px;
  padding: 10px;
}

.hamburger span {
  width: 28px;
  height: 3px;
  background: var(--notion-blue);
  transition: all 0.3s ease;
  border-radius: 2px;
}

/* ========================================
   Blog Hero Section
   ======================================== */
.blog-hero {
  background: var(--notion-surface);
  border-bottom: 1px solid var(--notion-border);
  padding: var(--spacing-xxl) 0;
  margin-top: var(--header-height);
}

.blog-hero-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.025em;
  color: var(--notion-text-primary);
  margin: 0;
  text-align: center;
}

/* ========================================
   Main Layout - 2 Column
   ======================================== */
.blog-layout {
  display: grid;
  grid-template-columns: 1fr var(--sidebar-width);
  gap: var(--spacing-xl);
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--spacing-xxl) var(--spacing-md);
}

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

/* ========================================
   Blog List Page - Article Cards
   ======================================== */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: var(--spacing-lg);
}

.blog-card {
  background: var(--notion-surface);
  border: 1px solid var(--notion-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all 0.2s ease;
  box-shadow: var(--notion-shadow);
}

.blog-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--notion-shadow-hover);
  border-color: var(--notion-border-hover);
}

.blog-card a {
  color: inherit;
  text-decoration: none;
  display: block;
}

/* Card Thumbnail (Featured Image) */
.card-thumb {
  position: relative;
  padding-top: 56.25%; /* 16:9 aspect ratio */
  overflow: hidden;
  background: linear-gradient(135deg, #e8f4fd 0%, #f6f5f4 100%);
}

.card-thumb img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.blog-card:hover .card-thumb img {
  transform: scale(1.05);
}

/* Card Body */
.card-body {
  padding: var(--spacing-md);
}

.card-body time {
  display: block;
  font-size: 0.875rem;
  color: var(--notion-text-secondary);
  margin-bottom: var(--spacing-sm);
  font-weight: 500;
}

.card-body h3 {
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: -0.01em;
  margin: 0 0 var(--spacing-sm);
  color: var(--notion-text-primary);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-body p {
  font-size: 0.9rem;
  color: var(--notion-text-secondary);
  line-height: 1.6;
  margin: 0;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ========================================
   Article Detail Page
   ======================================== */
.article-header {
  margin-bottom: var(--spacing-xxl);
  padding-bottom: var(--spacing-lg);
  border-bottom: 1px solid var(--notion-border);
}

.article-meta {
  display: flex;
  gap: var(--spacing-md);
  font-size: 0.95rem;
  color: var(--notion-text-secondary);
  margin-bottom: var(--spacing-md);
  flex-wrap: wrap;
}

.article-meta time {
  font-weight: 500;
}

/* Featured Image */
.article-featured-image {
  width: 100%;
  max-height: 480px;
  object-fit: cover;
  border-radius: var(--radius-md);
  margin-bottom: var(--spacing-xl);
  border: 1px solid var(--notion-border);
}

/* Article Content */
.article-content {
  color: var(--notion-text-primary);
  line-height: 1.8;
  font-size: 1.05rem;
}

.article-content h2 {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--notion-text-primary);
  margin: 2.5rem 0 1rem;
  padding-left: 1rem;
  border-left: 3px solid var(--notion-blue);
  letter-spacing: -0.015em;
}

.article-content h3 {
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--notion-text-primary);
  margin: 2rem 0 0.875rem;
  letter-spacing: -0.01em;
}

.article-content h4 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--notion-text-primary);
  margin: 1.5rem 0 0.625rem;
}

.article-content p {
  margin-bottom: 1.25rem;
  color: var(--notion-text-primary);
}

.article-content a {
  color: var(--notion-blue);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.article-content a:hover {
  text-decoration: none;
  color: var(--notion-blue-hover);
}

.article-content ul,
.article-content ol {
  margin: 1.25rem 0 1.25rem 1.5rem;
  padding: 0;
}

.article-content li {
  color: var(--notion-text-primary);
  margin-bottom: 0.625rem;
  line-height: 1.7;
}

.article-content img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  margin: 1.5rem 0;
  border: 1px solid var(--notion-border);
}

.article-content blockquote {
  border-left: 3px solid var(--notion-blue);
  margin: 1.5rem 0;
  padding: 0.75rem 0 0.75rem 1.25rem;
  color: var(--notion-text-secondary);
  font-style: italic;
  background: var(--notion-bg);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

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

/* Highlight Box */
.highlight-box,
.data-reference {
  background: var(--notion-bg);
  border: 1px solid var(--notion-border);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  margin: 1.5rem 0;
}

.highlight-box h3,
.data-reference h3 {
  margin-top: 0;
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--notion-text-primary);
}

/* Table of Contents */
.toc-container {
  background: var(--notion-bg);
  border: 1px solid var(--notion-border);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
  font-size: 0.95rem;
}

.toc-container summary {
  cursor: pointer;
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--notion-text-primary);
  list-style: none;
}

.toc-container summary::-webkit-details-marker {
  display: none;
}

.toc-list {
  margin: 0;
  padding-left: 1.2rem;
}

.toc-list li {
  margin: 0.5rem 0;
  line-height: 1.5;
  color: var(--notion-text-secondary);
}

.toc-list .toc-sub {
  margin-left: 1.2rem;
  font-size: 0.875rem;
  list-style-type: disc;
}

.toc-list a {
  text-decoration: none;
  color: var(--notion-blue);
}

.toc-list a:hover {
  text-decoration: underline;
}

/* Share Links */
.share-links {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--notion-border);
}

.share-links-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--notion-text-primary);
  margin-bottom: 1rem;
}

.share-buttons {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.share-buttons a {
  display: inline-block;
  padding: 0.5rem 1rem;
  border: 1px solid var(--notion-border);
  border-radius: var(--radius-sm);
  color: var(--notion-text-primary);
  font-size: 0.875rem;
  font-weight: 500;
  transition: all 0.2s ease;
  background: var(--notion-surface);
}

.share-buttons a:hover {
  border-color: var(--notion-blue);
  color: var(--notion-blue);
  background: rgba(0, 117, 222, 0.05);
}

/* ========================================
   Sidebar
   ======================================== */
.blog-sidebar {
  position: sticky;
  top: calc(var(--header-height) + var(--spacing-lg));
  align-self: start;
}

.sidebar-widget {
  background: var(--notion-surface);
  border: 1px solid var(--notion-border);
  border-radius: var(--radius-md);
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-md);
  box-shadow: var(--notion-shadow);
}

.sidebar-widget h3 {
  font-size: 1rem;
  font-weight: 700;
  margin: 0 0 1rem;
  color: var(--notion-text-primary);
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--notion-border);
  letter-spacing: -0.01em;
}

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

.sidebar-widget li {
  margin-bottom: 0.625rem;
}

.sidebar-widget a {
  color: var(--notion-text-secondary);
  font-size: 0.9rem;
  text-decoration: none;
  transition: color 0.2s;
  display: block;
  padding: 0.25rem 0;
}

.sidebar-widget a:hover {
  color: var(--notion-blue);
}

/* Ad Banner Widget */
.ad-banner {
  padding: 0.75rem;
  text-align: center;
}

.ad-banner img {
  max-width: 100%;
  border-radius: var(--radius-sm);
  transition: opacity 0.2s;
}

.ad-banner img:hover {
  opacity: 0.9;
}

/* Sitenavi & Amazon Ad Placeholder */
.sidebar-ad {
  padding: 0;
  overflow: hidden;
}

.sidebar-ad.amazon-ad {
  background: var(--notion-bg);
  border: 1px dashed var(--notion-border-hover);
  color: var(--notion-text-tertiary);
  font-size: 0.875rem;
  text-align: center;
}

.sidebar-ad.amazon-ad div {
  padding: 2rem 1rem;
}

.sidebar-ad [w3-include-html] {
  min-height: 120px;
}

/* ========================================
   Footer (matches main index.html)
   ======================================== */
.footer {
  background: var(--notion-surface);
  border-top: 1px solid var(--notion-border);
  padding: var(--spacing-xxl) 0 var(--spacing-lg);
  margin-top: var(--spacing-xxl);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer-section h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--notion-text-primary);
  margin: 0 0 1rem;
  letter-spacing: -0.01em;
}

.footer-section h4 {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--notion-text-primary);
  margin: 0 0 0.75rem;
}

.footer-section p {
  font-size: 0.9rem;
  color: var(--notion-text-secondary);
  line-height: 1.6;
  margin: 0;
}

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

.footer-section li {
  margin-bottom: 0.5rem;
}

.footer-section a {
  color: var(--notion-text-secondary);
  font-size: 0.9rem;
  text-decoration: none;
  transition: color 0.2s;
}

.footer-section a:hover {
  color: var(--notion-blue);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--notion-border);
}

.footer-bottom p {
  font-size: 0.875rem;
  color: var(--notion-text-tertiary);
  margin: 0;
}

.footer-links {
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.footer-links a {
  font-size: 0.875rem;
  color: var(--notion-text-tertiary);
  text-decoration: none;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: var(--notion-blue);
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 968px) {
  .blog-layout {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }
  
  .blog-sidebar {
    position: static;
  }
  
  .blog-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--notion-surface);
    flex-direction: column;
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--notion-border);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  }
  
  .nav.active {
    display: flex;
  }
  
  .hamburger {
    display: flex;
  }
  
  .blog-hero {
    padding: var(--spacing-xl) 0;
  }
  
  .blog-hero-title {
    font-size: 1.75rem;
  }
  
  .blog-layout {
    grid-template-columns: 1fr;
    padding: var(--spacing-xl) var(--spacing-sm);
  }
  
  .blog-sidebar {
    position: static;
    margin-top: var(--spacing-xl);
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }
  
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
}

/* ========================================
   Utility Classes
   ======================================== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.text-center {
  text-align: center;
}

.mt-lg {
  margin-top: var(--spacing-xl);
}

.mb-lg {
  margin-bottom: var(--spacing-xl);
}

/* Pill Badge */
.pill-badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  background: rgba(0, 117, 222, 0.1);
  color: var(--notion-blue);
  border-radius: 9999px;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.025em;
}

/* Scroll to Top */
.scroll-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: var(--notion-blue);
  color: #ffffff;
  border: none;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  box-shadow: var(--notion-shadow);
  transition: all 0.2s ease;
  opacity: 0;
  visibility: hidden;
}

.scroll-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.scroll-to-top:hover {
  background: var(--notion-blue-hover);
  transform: translateY(-2px);
}