/**
 * CSZ Production — Blog Stylesheet
 * Self-contained editorial styles for the PHP + Markdown blog engine.
 * Pure CSS with CSS custom properties matching the main CSZ Production design system.
 */

:root {
  /* Surface & Palette */
  --bg-color: #0a0a0c;
  --card-bg: #101012;
  --card-bg-elevated: #161619;
  --surface-hover: #151518;
  
  /* Text */
  --text-main: #e4e4e7;
  --text-heading: #ffffff;
  --text-muted: #a1a1aa;
  --text-dim: #71717a;
  
  /* Accent */
  --turquoise: #14b8a6;
  --turquoise-hover: #0d9488;
  --turquoise-bright: #2dd4bf;
  --turquoise-subtle: rgba(20, 184, 166, 0.1);
  --turquoise-glow: rgba(20, 184, 166, 0.25);
  
  /* Borders */
  --border-subtle: rgba(255, 255, 255, 0.07);
  --border-hover: rgba(255, 255, 255, 0.16);
  --border-card-hover: rgba(20, 184, 166, 0.35);
  --border-focus: #14b8a6;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-display: 'Montserrat', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

*, *::before, *::after {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  background-color: var(--bg-color);
  color: var(--text-main);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

::selection {
  background-color: rgba(20, 184, 166, 0.3);
  color: #ffffff;
}

/* ==========================================================================
   Blog Header (Restrained, Unified with Main Site)
   ========================================================================== */

.blog-header {
  border-bottom: 1px solid var(--border-subtle);
  background: rgba(10, 10, 12, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 40;
}

.blog-header-inner {
  max-width: 75rem; /* 1200px */
  margin: 0 auto;
  padding: 1.125rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.blog-brand {
  display: inline-flex;
  align-items: baseline;
  gap: 0.375rem;
  text-decoration: none;
  color: #ffffff;
  outline: none;
  transition: opacity 0.2s ease;
}

.blog-brand:hover {
  opacity: 0.9;
}

.blog-brand:focus-visible {
  outline: 2px solid var(--turquoise);
  outline-offset: 4px;
  border-radius: 4px;
}

.blog-brand-csz {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  color: #ffffff;
  transition: color 0.2s ease;
}

.blog-brand:hover .blog-brand-csz {
  color: var(--turquoise);
}

.blog-brand-prod {
  font-family: var(--font-sans);
  font-weight: 400;
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.blog-brand-dot {
  display: inline-block;
  width: 5px;
  height: 5px;
  border-radius: 9999px;
  background-color: var(--turquoise);
  margin-left: 0.125rem;
  position: relative;
  top: -2px;
}

.blog-header-link {
  font-size: 0.8125rem;
  font-weight: 400;
  color: var(--text-muted);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.375rem 0.5rem;
  border-radius: 6px;
  transition: color 0.2s ease, background-color 0.2s ease;
  white-space: nowrap;
}

.blog-header-link:hover {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.04);
}

.blog-header-link:focus-visible {
  outline: 2px solid var(--turquoise);
  outline-offset: 2px;
}

.blog-header-arrow {
  font-size: 0.875rem;
  color: var(--turquoise);
  transition: transform 0.2s ease;
}

.blog-header-link:hover .blog-header-arrow {
  transform: translateX(3px);
}

/* ==========================================================================
   Blog Index Main Layout & Hero
   ========================================================================== */

.blog-main {
  flex: 1 0 auto;
  width: 100%;
  max-width: 75rem; /* 1200px */
  margin: 0 auto;
  padding: 3rem 1.5rem 5rem;
}

.blog-hero {
  margin-bottom: 2.75rem;
}

.blog-eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--turquoise);
  margin-bottom: 0.75rem;
}

.blog-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.25rem, 5vw, 3.25rem);
  color: var(--text-heading);
  letter-spacing: -0.03em;
  margin: 0 0 0.875rem 0;
  line-height: 1.1;
}

.blog-subtitle {
  font-size: clamp(1rem, 2vw, 1.125rem);
  color: var(--text-muted);
  font-weight: 400;
  max-width: 38rem;
  margin: 0;
  line-height: 1.6;
}

/* ==========================================================================
   Category Filters (Horizontal Scrolling on Mobile, Premium Pills)
   ========================================================================== */

.blog-filters-wrapper {
  margin-bottom: 2.75rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border-subtle);
}

.blog-filters {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  overflow-x: auto;
  scrollbar-width: none; /* Firefox */
  -ms-overflow-style: none; /* IE and Edge */
  -webkit-overflow-scrolling: touch;
  padding: 0.25rem 0;
}

.blog-filters::-webkit-scrollbar {
  display: none; /* Chrome, Safari, Opera */
}

.blog-filter-btn {
  display: inline-flex;
  align-items: center;
  padding: 0.4rem 0.95rem;
  border-radius: 9999px;
  font-size: 0.8125rem;
  font-weight: 500;
  text-decoration: none;
  white-space: nowrap;
  transition: all 0.2s ease;
  cursor: pointer;
  background-color: #111114;
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
}

.blog-filter-btn:hover {
  color: #ffffff;
  border-color: var(--border-hover);
  background-color: var(--card-bg-elevated);
}

.blog-filter-btn.active {
  background-color: rgba(20, 184, 166, 0.12);
  border-color: var(--turquoise);
  color: var(--turquoise-bright);
  font-weight: 600;
}

.blog-filter-btn:focus-visible {
  outline: 2px solid var(--turquoise);
  outline-offset: 2px;
}

/* Empty State */
.blog-empty {
  padding: 4rem 2rem;
  text-align: center;
  background-color: rgba(16, 16, 18, 0.5);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  margin: 1rem 0;
}

.blog-empty p {
  color: var(--text-main);
  font-size: 1.0625rem;
  margin: 0 0 1rem 0;
}

.blog-empty-link {
  display: inline-flex;
  align-items: center;
  color: var(--turquoise);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  border-bottom: 1px solid rgba(20, 184, 166, 0.4);
  transition: all 0.2s ease;
}

.blog-empty-link:hover {
  color: var(--turquoise-bright);
  border-color: var(--turquoise-bright);
}

/* ==========================================================================
   Editorial Article Grid (Desktop 3-col, Tablet 2-col, Mobile 1-col)
   ========================================================================== */

.blog-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

@media (max-width: 1024px) {
  .blog-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
  }
}

@media (max-width: 640px) {
  .blog-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
}

/* ==========================================================================
   Article Card
   ========================================================================== */

.blog-card {
  display: flex;
  flex-direction: column;
  background-color: var(--card-bg);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  transition: transform 0.2s cubic-bezier(0.16, 1, 0.3, 1),
              border-color 0.2s ease,
              box-shadow 0.2s ease;
  outline: none;
}

.blog-card:hover {
  transform: translateY(-2px);
  border-color: var(--border-card-hover);
  box-shadow: 0 10px 24px -6px rgba(0, 0, 0, 0.45);
}

.blog-card:focus-visible {
  border-color: var(--turquoise);
  outline: 2px solid var(--turquoise);
  outline-offset: 2px;
}

/* Card Media (Consistent 16:10 Ratio) - when image is present */
.blog-card-media {
  width: 100%;
  aspect-ratio: 16 / 10;
  background-color: var(--card-bg-elevated);
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--border-subtle);
}

.blog-card-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* Card Content */
.blog-card-body {
  padding: 1.25rem 1.375rem 1.375rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.blog-card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  font-size: 0.75rem;
  margin-bottom: 0.75rem;
}

.blog-card-meta time {
  color: var(--text-dim);
  font-family: var(--font-sans);
  font-size: 0.75rem;
  white-space: nowrap;
}

.blog-badge {
  display: inline-block;
  padding: 0.2rem 0.55rem;
  border-radius: 4px;
  background: rgba(20, 184, 166, 0.08);
  border: 1px solid rgba(20, 184, 166, 0.2);
  color: var(--turquoise);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  white-space: nowrap;
}

.blog-card-title {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-heading);
  margin: 0 0 0.5rem 0;
  line-height: 1.35;
  letter-spacing: -0.01em;
  transition: color 0.2s ease;
}

.blog-card:hover .blog-card-title {
  color: var(--turquoise);
}

.blog-card-desc {
  font-size: 0.84375rem;
  color: var(--text-muted);
  line-height: 1.55;
  margin: 0;
  font-weight: 400;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ==========================================================================
   Article Page Layout (Reading Column ~720-820px)
   ========================================================================== */

.article-wrapper {
  max-width: 50rem; /* ~800px */
  margin: 0 auto;
  padding: 2.5rem 1.5rem 5rem;
  width: 100%;
}

.article-container {
  width: 100%;
}

/* Article Intro */
.article-intro {
  margin-bottom: 2.5rem;
}

.article-backlink {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  font-size: 0.8125rem;
  color: var(--text-muted);
  text-decoration: none;
  margin-bottom: 1.75rem;
  transition: color 0.2s ease;
}

.article-backlink:hover {
  color: var(--turquoise);
}

.article-backlink:focus-visible {
  outline: 2px solid var(--turquoise);
  outline-offset: 2px;
  border-radius: 4px;
}

.article-backlink-arrow {
  font-size: 0.875rem;
  transition: transform 0.2s ease;
}

.article-backlink:hover .article-backlink-arrow {
  transform: translateX(-3px);
}

.article-category-wrap {
  margin-bottom: 1rem;
}

.article-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2rem, 4.5vw, 2.875rem);
  color: var(--text-heading);
  letter-spacing: -0.025em;
  line-height: 1.18;
  margin: 0 0 1.25rem 0;
}

.article-lead {
  font-size: 1.1875rem;
  color: #d4d4d8;
  font-weight: 400;
  line-height: 1.65;
  margin: 0 0 1.5rem 0;
}

.article-meta-line {
  font-size: 0.8125rem;
  color: var(--text-dim);
  padding-bottom: 1.75rem;
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 2.5rem;
}

.article-meta-line time {
  font-family: var(--font-sans);
  color: var(--text-dim);
}

/* Responsive Hero Image on Article Page (Wide Landscape) */
.article-hero-wrap {
  margin-bottom: 2.75rem;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--border-subtle);
  background-color: var(--card-bg-elevated);
}

.article-hero-img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  display: block;
}

/* ==========================================================================
   Editorial Markdown Body Typography
   ========================================================================== */

.article-content {
  color: var(--text-main);
  font-size: 1.0625rem;
  line-height: 1.75;
}

.article-content p {
  margin: 0 0 1.5rem 0;
  font-weight: 400;
}

.article-content h1,
.article-content h2,
.article-content h3,
.article-content h4 {
  font-family: var(--font-display);
  color: var(--text-heading);
  line-height: 1.3;
}

.article-content h1 {
  font-size: clamp(1.625rem, 3.5vw, 2rem);
  font-weight: 800;
  margin: 3rem 0 1.125rem 0;
  letter-spacing: -0.02em;
}

.article-content h2 {
  font-size: clamp(1.375rem, 3vw, 1.625rem);
  font-weight: 700;
  margin: 2.75rem 0 1rem 0;
  letter-spacing: -0.015em;
  padding-top: 0.5rem;
}

.article-content h3 {
  font-size: clamp(1.1875rem, 2.5vw, 1.3125rem);
  font-weight: 600;
  margin: 2.25rem 0 0.875rem 0;
  letter-spacing: -0.01em;
}

.article-content ul,
.article-content ol {
  margin: 0 0 1.625rem 0;
  padding-left: 1.5rem;
}

.article-content ul {
  list-style-type: disc;
}

.article-content ol {
  list-style-type: decimal;
}

.article-content li {
  margin-bottom: 0.625rem;
  line-height: 1.7;
}

.article-content li::marker {
  color: var(--turquoise);
}

.article-content blockquote {
  margin: 2rem 0;
  padding: 1.25rem 1.5rem;
  border-left: 3px solid var(--turquoise);
  background-color: #101013;
  border-radius: 0 8px 8px 0;
  font-style: italic;
  color: #f4f4f5;
  border-top: 1px solid rgba(255, 255, 255, 0.04);
  border-right: 1px solid rgba(255, 255, 255, 0.04);
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
}

.article-content blockquote p {
  margin: 0;
}

.article-content a {
  color: var(--turquoise);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.15s ease;
}

.article-content a:hover {
  color: var(--turquoise-bright);
}

.article-content a:focus-visible {
  outline: 2px solid var(--turquoise);
  outline-offset: 2px;
  border-radius: 2px;
}

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

.article-content em {
  font-style: italic;
  color: #f4f4f5;
}

.article-content code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  padding: 0.2em 0.45em;
  background-color: #161619;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 4px;
  color: var(--turquoise-bright);
}

.article-content pre {
  margin: 2rem 0;
  padding: 1.25rem;
  background-color: #101013;
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  overflow-x: auto;
}

.article-content pre code {
  padding: 0;
  background: none;
  border: none;
  color: var(--text-main);
}

.article-content hr {
  margin: 3rem 0;
  border: none;
  border-top: 1px solid var(--border-subtle);
}

/* Return to Blog link at article bottom */
.article-nav-blog {
  margin-top: 3.5rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--border-subtle);
}

.article-nav-back {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s ease;
}

.article-nav-back:hover {
  color: var(--turquoise);
}

.article-nav-back:focus-visible {
  outline: 2px solid var(--turquoise);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ==========================================================================
   Contextual Editorial Transition to Main Site
   ========================================================================== */

.article-transition-block {
  margin-top: 2.5rem;
  padding: 2.25rem;
  background: #101013;
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  position: relative;
}

.article-transition-text {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  line-height: 1.6;
  color: #f4f4f5;
  font-weight: 500;
  margin: 0 0 1.5rem 0;
  max-width: 38rem;
}

.article-transition-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1.75rem;
}

.article-transition-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--turquoise);
  text-decoration: none;
  padding: 0.25rem 0;
  border-bottom: 1px solid transparent;
  transition: all 0.2s ease;
}

.article-transition-link:hover {
  color: #ffffff;
  border-color: var(--turquoise);
}

.article-transition-link:focus-visible {
  outline: 2px solid var(--turquoise);
  outline-offset: 4px;
  border-radius: 2px;
}

.article-transition-arrow {
  font-size: 0.875rem;
  transition: transform 0.2s ease;
}

.article-transition-link:hover .article-transition-arrow {
  transform: translateX(4px);
}

@media (max-width: 640px) {
  .article-transition-block {
    padding: 1.5rem;
  }
  .article-transition-links {
    gap: 1rem;
    flex-direction: column;
    align-items: flex-start;
  }
}

/* ==========================================================================
   404 Error Card
   ========================================================================== */

.blog-404-container {
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 1 0 auto;
  padding: 3rem 1.5rem;
}

.blog-404-card {
  text-align: center;
  max-width: 28rem;
  width: 100%;
  background-color: var(--card-bg);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  padding: 3rem 2rem;
  box-shadow: 0 20px 40px -10px rgba(0, 0, 0, 0.5);
}

.blog-404-num {
  font-size: 3.5rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--turquoise);
  margin-bottom: 0.75rem;
  line-height: 1;
}

.blog-404-title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-heading);
  margin: 0 0 0.75rem 0;
  letter-spacing: -0.01em;
}

.blog-404-desc {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin: 0 0 2rem 0;
}

.blog-btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.625rem 1.375rem;
  background-color: var(--turquoise);
  color: #0a0a0c;
  font-weight: 600;
  font-size: 0.875rem;
  border-radius: 9999px;
  text-decoration: none;
  transition: all 0.2s ease;
}

.blog-btn-primary:hover {
  background-color: var(--turquoise-bright);
  color: #0a0a0c;
  box-shadow: 0 4px 14px var(--turquoise-glow);
}

.blog-btn-primary:focus-visible {
  outline: 2px solid var(--turquoise);
  outline-offset: 2px;
}

/* ==========================================================================
   Minimal Blog Footer
   ========================================================================== */

.blog-footer {
  border-top: 1px solid var(--border-subtle);
  background-color: var(--bg-color);
  padding: 2.25rem 1.5rem;
  margin-top: auto;
}

.blog-footer-inner {
  max-width: 75rem; /* 1200px */
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.blog-footer-brand {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.blog-footer-logo {
  display: inline-flex;
  align-items: baseline;
  gap: 0.375rem;
  text-decoration: none;
  outline: none;
}

.blog-footer-logo:focus-visible {
  outline: 2px solid var(--turquoise);
  outline-offset: 2px;
  border-radius: 4px;
}

.blog-footer-copy {
  font-size: 0.8125rem;
  color: var(--text-dim);
  margin: 0;
}

.blog-footer-nav {
  display: flex;
  align-items: center;
  gap: 1.75rem;
}

.blog-footer-link {
  font-size: 0.8125rem;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s ease;
}

.blog-footer-link:hover {
  color: var(--turquoise);
}

.blog-footer-link:focus-visible {
  outline: 2px solid var(--turquoise);
  outline-offset: 2px;
  border-radius: 4px;
}

@media (max-width: 640px) {
  .blog-footer-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 1.25rem;
  }
  .blog-footer-brand {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
  }
  .blog-footer-nav {
    gap: 1.25rem;
  }
}

/* ==========================================================================
   Accessibility: Reduced Motion
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}