@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500;600&family=Lora:ital,wght@0,400;0,500;1,400&display=swap');

:root {
  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-serif: 'Lora', Georgia, serif;
  --font-mono: 'JetBrains Mono', SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  /* Dark Theme (Default) */
  --bg-primary: #0a0d14;
  --bg-secondary: #121824;
  --bg-tertiary: #1a2234;
  --bg-card: rgba(18, 24, 36, 0.7);
  --bg-card-hover: rgba(26, 34, 52, 0.9);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(59, 130, 246, 0.4);
  
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  
  --accent-blue: #3b82f6;
  --accent-blue-glow: rgba(59, 130, 246, 0.25);
  --accent-cyan: #06b6d4;
  --accent-emerald: #10b981;
  --accent-purple: #8b5cf6;
  --accent-amber: #f59e0b;

  --nav-bg: rgba(10, 13, 20, 0.85);
  --code-bg: #0d131f;
  --callout-bg: rgba(59, 130, 246, 0.08);
  --callout-border: #3b82f6;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.6);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
}

[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f1f5f9;
  --bg-card: rgba(255, 255, 255, 0.9);
  --bg-card-hover: #ffffff;
  --border-color: rgba(0, 0, 0, 0.08);
  --border-hover: rgba(59, 130, 246, 0.5);
  
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;

  --nav-bg: rgba(255, 255, 255, 0.85);
  --code-bg: #f1f5f9;
  --callout-bg: rgba(59, 130, 246, 0.06);
  --callout-border: #2563eb;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.12);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.65;
  transition: background-color 0.3s ease, color 0.3s ease;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
  transition: all 0.2s ease;
}

/* Header & Nav */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background-color: var(--nav-bg);
  border-bottom: 1px solid var(--border-color);
}

.nav-container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
}

.logo-badge {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-cyan));
  color: white;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 800;
  box-shadow: 0 0 12px var(--accent-blue-glow);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
}

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

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

.theme-toggle-btn {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1rem;
  transition: all 0.2s ease;
}

.theme-toggle-btn:hover {
  border-color: var(--border-hover);
  transform: rotate(15deg);
}

/* Hero Section */
.hero {
  position: relative;
  overflow: hidden;
  padding: 64px 24px 48px;
  background: radial-gradient(circle at 50% 0%, var(--accent-blue-glow) 0%, transparent 65%);
}

.hero-container {
  max-width: 1080px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 48px;
}

@media (max-width: 768px) {
  .hero-container {
    flex-direction: column;
    text-align: center;
    gap: 32px;
  }
}

.hero-avatar-wrap {
  position: relative;
  flex-shrink: 0;
}

.hero-avatar {
  width: 160px;
  height: 160px;
  border-radius: var(--radius-full);
  object-fit: cover;
  border: 3px solid var(--accent-blue);
  box-shadow: 0 0 32px var(--accent-blue-glow);
  transition: transform 0.3s ease;
}

.hero-avatar:hover {
  transform: scale(1.03);
}

.hero-badge-status {
  position: absolute;
  bottom: 6px;
  right: 6px;
  background: var(--bg-secondary);
  border: 2px solid var(--border-color);
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-emerald);
  display: flex;
  align-items: center;
  gap: 6px;
  box-shadow: var(--shadow-sm);
}

.pulse-dot {
  width: 8px;
  height: 8px;
  background-color: var(--accent-emerald);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
  70% { transform: scale(1); box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.hero-content {
  flex: 1;
}

.hero-greeting {
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent-blue);
  margin-bottom: 8px;
}

.hero-title {
  font-size: 2.75rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 16px;
  background: linear-gradient(135deg, var(--text-primary) 30%, var(--text-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-bio {
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 24px;
  max-width: 640px;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag-pill {
  font-size: 0.8rem;
  font-weight: 600;
  padding: 6px 14px;
  border-radius: var(--radius-full);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  transition: all 0.2s ease;
}

.tag-pill:hover {
  color: var(--accent-blue);
  border-color: var(--accent-blue);
  transform: translateY(-1px);
}

/* Main Content Area */
.main-container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: 28px;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: 10px;
}

.section-title::before {
  content: '';
  display: inline-block;
  width: 4px;
  height: 20px;
  background: var(--accent-blue);
  border-radius: 2px;
}

/* Featured Article Card */
.featured-card {
  position: relative;
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px;
  margin-bottom: 48px;
  box-shadow: var(--shadow-md);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  overflow: hidden;
  display: block;
}

.featured-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-blue), var(--accent-cyan), var(--accent-purple));
}

.featured-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-lg), 0 0 30px var(--accent-blue-glow);
}

.card-meta {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.badge-featured {
  background: rgba(59, 130, 246, 0.15);
  color: var(--accent-blue);
  border: 1px solid rgba(59, 130, 246, 0.3);
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.featured-title {
  font-size: 1.85rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.3;
  margin-bottom: 14px;
  color: var(--text-primary);
}

.featured-excerpt {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 24px;
}

.featured-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

.author-mini {
  display: flex;
  align-items: center;
  gap: 10px;
}

.author-mini img {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--accent-blue);
}

.author-mini-name {
  font-size: 0.9rem;
  font-weight: 600;
}

.btn-read-more {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--accent-blue);
  color: white;
  padding: 10px 22px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.9rem;
  box-shadow: 0 4px 14px var(--accent-blue-glow);
  transition: all 0.2s ease;
}

.btn-read-more:hover {
  background: #2563eb;
  transform: translateX(2px);
}

/* Post Layout */
.post-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 48px;
}

@media (max-width: 960px) {
  .post-layout {
    grid-template-columns: 1fr;
  }
  .post-sidebar {
    display: none;
  }
}

.post-article {
  min-width: 0;
}

.post-header {
  margin-bottom: 36px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 28px;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 16px;
}

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

.post-title {
  font-size: 2.5rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.2;
  margin-bottom: 18px;
}

.post-meta-bar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* Post Body Content Styles */
.post-content {
  font-size: 1.1rem;
  line-height: 1.75;
  color: var(--text-primary);
}

.post-content h2 {
  font-size: 1.65rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-top: 48px;
  margin-bottom: 18px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-primary);
}

.post-content h3 {
  font-size: 1.3rem;
  font-weight: 600;
  margin-top: 32px;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.post-content p {
  margin-bottom: 20px;
  color: var(--text-secondary);
}

.post-content ul, .post-content ol {
  margin-bottom: 24px;
  padding-left: 28px;
  color: var(--text-secondary);
}

.post-content li {
  margin-bottom: 8px;
}

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

.post-content code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--code-bg);
  padding: 3px 7px;
  border-radius: 4px;
  color: var(--accent-cyan);
  border: 1px solid var(--border-color);
}

.code-block-wrapper {
  position: relative;
  margin: 24px 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border-color);
  background: var(--code-bg);
}

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 16px;
  background: rgba(0, 0, 0, 0.2);
  border-bottom: 1px solid var(--border-color);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.code-copy-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 0.8rem;
  padding: 4px 8px;
  border-radius: 4px;
  transition: all 0.2s ease;
}

.code-copy-btn:hover {
  color: var(--text-primary);
  background: var(--bg-tertiary);
}

.code-block-wrapper pre {
  margin: 0;
  padding: 16px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.5;
  color: var(--text-primary);
}

.callout-box {
  background: var(--callout-bg);
  border-left: 4px solid var(--callout-border);
  padding: 20px 24px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 28px 0;
}

.callout-box h4 {
  color: var(--accent-blue);
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.callout-box p {
  margin-bottom: 10px;
}

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

/* Sidebar / Table of Contents */
.post-sidebar {
  position: sticky;
  top: 96px;
  height: fit-content;
  max-height: calc(100vh - 120px);
  overflow-y: auto;
  padding: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
}

.toc-title {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-bottom: 16px;
}

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

.toc-item {
  margin-bottom: 10px;
}

.toc-link {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.4;
  display: block;
  transition: color 0.2s ease;
}

.toc-link:hover, .toc-link.active {
  color: var(--accent-blue);
  font-weight: 600;
}

/* Reading Progress Bar */
.reading-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-blue), var(--accent-cyan));
  z-index: 200;
  width: 0%;
  transition: width 0.1s ease;
}

/* Author Bio Card at Post End */
.author-card-end {
  margin-top: 56px;
  padding: 32px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  gap: 24px;
}

.author-card-avatar {
  width: 96px;
  height: 96px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--accent-blue);
  flex-shrink: 0;
}

.author-card-info h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.author-card-info p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 0;
}

/* Footer */
.footer {
  border-top: 1px solid var(--border-color);
  background-color: var(--bg-primary);
  padding: 40px 24px;
  margin-top: 64px;
}

.footer-container {
  max-width: 1080px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
  font-size: 0.9rem;
  color: var(--text-muted);
}