/* ==========================================
   Jason Tech Blog - CSS Tokens & System
   Theme: Cybernetic Workbench / Terminal Minimal
   ========================================== */

:root {
  /* Color Palette - Dark Obsidian (Default) */
  --bg-main: #0B0F17;
  --bg-surface: #111827;
  --bg-card: #1E293B;
  --bg-card-hover: #26334D;
  --bg-input: #0F172A;
  
  --border-color: #1E293B;
  --border-highlight: #334155;
  
  --text-primary: #F8FAFC;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;
  
  --accent-cyan: #00F0FF;
  --accent-cyan-glow: rgba(0, 240, 255, 0.15);
  --accent-emerald: #10B981;
  --accent-emerald-glow: rgba(16, 185, 129, 0.15);
  --accent-purple: #A855F7;
  
  --code-bg: #0D1117;
  --code-text: #E6EDE3;
  --terminal-bar: #161F30;
  
  /* Typography */
  --font-sans: "Noto Sans TC", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
  
  /* Layout & Spacing */
  --container-width: 1080px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  
  --shadow-card: 0 4px 20px -2px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 25px var(--accent-cyan-glow);
}

:root[data-theme="light"] {
  /* Light Theme Overrides */
  --bg-main: #F8FAFC;
  --bg-surface: #FFFFFF;
  --bg-card: #FFFFFF;
  --bg-card-hover: #F1F5F9;
  --bg-input: #F1F5F9;
  
  --border-color: #E2E8F0;
  --border-highlight: #CBD5E1;
  
  --text-primary: #0F172A;
  --text-secondary: #475569;
  --text-muted: #64748B;
  
  --accent-cyan: #0284C7;
  --accent-cyan-glow: rgba(2, 132, 199, 0.12);
  --accent-emerald: #059669;
  --accent-emerald-glow: rgba(5, 150, 105, 0.12);
  --accent-purple: #7E22CE;
  
  --code-bg: #1E293B;
  --code-text: #F8FAFC;
  --terminal-bar: #E2E8F0;
  
  --shadow-card: 0 4px 20px -2px rgba(0, 0, 0, 0.05);
  --shadow-glow: 0 0 20px rgba(2, 132, 199, 0.15);
}

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  background-color: var(--bg-main);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  -webkit-font-smoothing: antialiased;
}

/* Reading Progress Bar */
#reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-cyan), var(--accent-emerald));
  width: 0%;
  z-index: 1000;
  transition: width 0.1s linear;
}

/* Container */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header & Nav */
.site-header {
  position: sticky;
  top: 0;
  z-index: 900;
  background-color: rgba(11, 15, 23, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

:root[data-theme="light"] .site-header {
  background-color: rgba(248, 250, 252, 0.85);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.25rem;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.15rem;
}

.brand-logo .prompt-symbol {
  color: var(--accent-cyan);
  font-weight: 900;
}

.brand-logo .logo-tag {
  font-size: 0.75rem;
  background-color: var(--accent-cyan-glow);
  color: var(--accent-cyan);
  border: 1px solid var(--accent-cyan);
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-sm);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 1.75rem;
  list-style: none;
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}

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

/* Theme Toggle Button */
.theme-toggle-btn {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  width: 2.4rem;
  height: 2.4rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  box-shadow: var(--shadow-glow);
}

/* Hero Section */
.hero-section {
  padding: 4rem 0 3rem;
  border-bottom: 1px solid var(--border-color);
}

.hero-terminal {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.terminal-header {
  background: var(--terminal-bar);
  padding: 0.6rem 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

.terminal-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.dot-red { background: #FF5F56; }
.dot-yellow { background: #FFBD2E; }
.dot-green { background: #27C93F; }

.terminal-title {
  margin-left: auto;
  margin-right: auto;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.hero-body {
  padding: 2.5rem 2rem;
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 2.5rem;
  align-items: center;
}

@media (max-width: 860px) {
  .hero-body {
    grid-template-columns: 1fr;
  }
}

.hero-content h1 {
  font-size: 2.25rem;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}

.hero-content h1 .highlight {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-emerald));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-content p {
  color: var(--text-secondary);
  font-size: 1.05rem;
  margin-bottom: 1.5rem;
  max-width: 620px;
}

.tech-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.tech-tag {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-sm);
  background: var(--bg-input);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
}

.author-card {
  background: var(--bg-main);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  text-align: center;
}

.avatar-ring {
  width: 90px;
  height: 90px;
  border-radius: 50%;
  margin: 0 auto 1rem;
  padding: 3px;
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple));
}

.avatar-ring img, .avatar-ring .avatar-placeholder {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  object-fit: cover;
  background: var(--bg-surface);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.2rem;
  color: var(--accent-cyan);
}

.author-name {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.author-role {
  font-size: 0.85rem;
  color: var(--accent-emerald);
  font-family: var(--font-mono);
  margin-bottom: 0.75rem;
}

.author-bio {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.social-links {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
}

.social-icon {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color var(--transition-fast);
}

.social-icon:hover {
  color: var(--accent-cyan);
}

/* Filter & Search Bar */
.filter-section {
  padding: 2.5rem 0 1.5rem;
}

.filter-bar {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.filter-command {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.filter-command .cmd-prompt {
  color: var(--accent-emerald);
}

.tag-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.tag-btn {
  background: var(--bg-main);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  padding: 0.3rem 0.75rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.tag-btn:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}

.tag-btn.active {
  background: var(--accent-cyan-glow);
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  font-weight: 600;
}

.search-box {
  position: relative;
  min-width: 220px;
}

.search-input {
  width: 100%;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  padding: 0.45rem 0.75rem 0.45rem 2.2rem;
  font-size: 0.85rem;
  outline: none;
  transition: border-color var(--transition-fast);
}

.search-input:focus {
  border-color: var(--accent-cyan);
}

.search-icon {
  position: absolute;
  left: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 0.85rem;
  pointer-events: none;
}

/* Articles Grid */
.articles-section {
  padding: 1rem 0 4rem;
}

.section-title {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.section-title::before {
  content: "//";
  color: var(--accent-cyan);
  font-family: var(--font-mono);
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}

.article-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: transform var(--transition-normal), border-color var(--transition-normal), box-shadow var(--transition-normal);
  text-decoration: none;
  color: inherit;
}

.article-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-cyan);
  box-shadow: var(--shadow-glow);
}

.card-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
  margin-bottom: 0.75rem;
}

.card-category {
  color: var(--accent-cyan);
  font-weight: 600;
}

.article-card h2 {
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.article-card p {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.25rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.read-more {
  color: var(--accent-cyan);
  font-family: var(--font-mono);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

/* Article Detail Page */
.article-detail-section {
  padding: 3rem 0 5rem;
}

.article-header {
  max-width: 800px;
  margin: 0 auto 3rem;
  text-align: center;
}

.article-header .card-meta {
  justify-content: center;
  margin-bottom: 1rem;
}

.article-title {
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 1.25rem;
  letter-spacing: -0.02em;
}

@media (max-width: 640px) {
  .article-title { font-size: 1.85rem; }
}

.article-subtitle {
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.article-layout {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 3rem;
  max-width: 1000px;
  margin: 0 auto;
}

@media (max-width: 900px) {
  .article-layout {
    grid-template-columns: 1fr;
  }
  .toc-sidebar {
    display: none;
  }
}

.toc-sidebar {
  position: sticky;
  top: 5.5rem;
  height: fit-content;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
}

.toc-title {
  font-size: 0.9rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--accent-cyan);
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.toc-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  font-size: 0.85rem;
}

.toc-list a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
  display: block;
}

.toc-list a:hover, .toc-list a.active {
  color: var(--accent-cyan);
  font-weight: 500;
}

.prose {
  color: var(--text-primary);
  font-size: 1.05rem;
  line-height: 1.8;
}

.prose p {
  margin-bottom: 1.5rem;
}

.prose h2 {
  font-size: 1.65rem;
  font-weight: 700;
  margin: 2.5rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-primary);
}

.prose h3 {
  font-size: 1.3rem;
  font-weight: 600;
  margin: 2rem 0 0.75rem;
}

.prose ul, .prose ol {
  margin: 1rem 0 1.5rem 1.5rem;
}

.prose li {
  margin-bottom: 0.5rem;
}

.prose blockquote {
  border-left: 4px solid var(--accent-cyan);
  background: var(--bg-surface);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 1.5rem 0;
  color: var(--text-secondary);
  font-style: italic;
}

.prose code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--bg-input);
  color: var(--accent-cyan);
  padding: 0.2em 0.4em;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}

.prose pre {
  background: var(--code-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  overflow-x: auto;
  margin: 1.5rem 0;
  position: relative;
}

.prose pre code {
  background: none;
  color: var(--code-text);
  padding: 0;
  border: none;
  font-size: 0.9em;
  line-height: 1.6;
}

.copy-code-btn {
  position: absolute;
  top: 0.6rem;
  right: 0.6rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.copy-code-btn:hover {
  color: var(--accent-cyan);
  border-color: var(--accent-cyan);
}

/* FAQ Box */
.faq-box {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin: 3rem 0;
}

.faq-item {
  margin-bottom: 1.25rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border-color);
}

.faq-item:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

.faq-question {
  font-weight: 700;
  font-size: 1.05rem;
  margin-bottom: 0.5rem;
  color: var(--accent-cyan);
}

/* Contact / Newsletter Section */
.subscribe-section {
  padding: 4rem 0;
  background: var(--bg-surface);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.subscribe-card {
  max-width: 650px;
  margin: 0 auto;
  text-align: center;
}

.subscribe-card h2 {
  font-size: 1.75rem;
  font-weight: 800;
  margin-bottom: 0.75rem;
}

.subscribe-card p {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.subscribe-form {
  display: flex;
  gap: 0.75rem;
  max-width: 480px;
  margin: 0 auto;
}

@media (max-width: 520px) {
  .subscribe-form { flex-direction: column; }
}

.subscribe-input {
  flex: 1;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.75rem 1rem;
  color: var(--text-primary);
  font-size: 0.95rem;
  outline: none;
}

.subscribe-input:focus {
  border-color: var(--accent-cyan);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-cyan), #00B8FF);
  color: #0B0F17;
  font-weight: 700;
  font-family: var(--font-mono);
  border: none;
  border-radius: var(--radius-md);
  padding: 0.75rem 1.5rem;
  cursor: pointer;
  transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.btn-primary:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

/* Footer */
.site-footer {
  padding: 3rem 0 2rem;
  margin-top: auto;
  border-top: 1px solid var(--border-color);
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

/* Back to Top */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  width: 2.6rem;
  height: 2.6rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-card);
}

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

.back-to-top:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}