/* ==========================================================================
   DARWIN CHEN — TECHNICAL BLOG STYLES
   ========================================================================== */

/* Page Wrapper & Layout */
.blog-wrap {
  max-width: 1400px;
  margin-inline: auto;
  padding: 2rem 5vw 6rem;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  width: 100%;
}

.article-wrap {
  max-width: 860px;
  margin-inline: auto;
  padding: 2rem 5vw 6rem;
  min-height: 100vh;
}

/* Reading Progress Bar (Top of Post Pages) */
.reading-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: var(--tech-accent);
  z-index: 999;
  width: 0%;
  transition: width 0.08s ease;
}

/* Nav Header */
.blog-hero-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1.25rem;
  padding-top: 1rem;
}

.blog-brand-mark {
  text-decoration: none;
  color: var(--text-main);
  display: inline-block;
  transition: opacity 0.2s ease;
}

.blog-brand-mark:hover {
  opacity: 0.75;
}

.blog-nav-actions {
  display: flex;
  gap: 0.75rem;
  align-items: center;
}

/* Backward compatibility for article post headers */
.blog-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 1.25rem;
  padding-top: 1rem;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 3.5rem;
}

.blog-nav-left {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.nav-back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 600;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s ease, transform 0.2s ease;
}

.nav-back-link:hover {
  color: var(--text-main);
  transform: translateX(-3px);
}

.blog-brand-title {
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-main);
  text-decoration: none;
  transition: opacity 0.2s ease;
}

.blog-brand-title:hover {
  opacity: 0.75;
}

.blog-nav-right {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* Hero Section */
.blog-hero {
  margin-bottom: 3.5rem;
}

.blog-meta-lead {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

/* Filter & Search Controls */
.blog-controls-section {
  width: 100%;
}

.blog-search-box {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-pill);
  border: 1px solid var(--border-color);
  background: var(--surface-color);
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}

.blog-search-box:focus-within {
  border-color: var(--border-strong);
  box-shadow: 0 0 0 2px rgba(74, 144, 226, 0.15);
}

.blog-search-box svg {
  color: var(--text-muted);
  flex-shrink: 0;
}

.minimal-search-input {
  border: none;
  background: transparent;
  color: var(--text-main);
  font-size: 0.82rem;
  font-family: inherit;
  outline: none;
  width: 200px;
  transition: width 0.3s ease;
}

.minimal-search-input:focus {
  width: 250px;
}

.blog-filter-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 1.5rem;
}

.filter-tabs {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.filter-tab {
  padding: 0.45rem 1rem;
  border-radius: var(--radius-pill);
  border: 1px solid var(--border-color);
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.filter-tab:hover {
  color: var(--text-main);
  border-color: var(--border-strong);
  transform: translateY(-1px);
}

.filter-tab.active {
  background: var(--text-main);
  color: var(--bg-color);
  border-color: var(--text-main);
}

/* Articles Grid */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 2rem;
}

.featured-card-col {
  grid-column: span 12;
}

.card-col-half {
  grid-column: span 6;
}

@media (max-width: 860px) {
  .card-col-half {
    grid-column: span 12;
  }
}

.blog-article-card {
  display: flex;
  flex-direction: column;
  padding: 2.5rem;
  border-radius: var(--radius-card);
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  text-decoration: none;
  color: var(--text-main);
  height: 100%;
  position: relative;
  transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1),
              border-color 0.3s ease,
              box-shadow 0.35s ease;
}

.blog-article-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-strong);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.04);
}

html[data-theme="dark"] .blog-article-card:hover {
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.35);
}

.card-top-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.card-meta-line {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.card-arrow-pill {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--border-color);
  background: var(--bg-color);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  flex-shrink: 0;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1),
              border-color 0.25s ease,
              color 0.25s ease,
              background 0.25s ease;
}

.blog-article-card:hover .card-arrow-pill {
  transform: translate(3px, -3px);
  color: var(--text-main);
  border-color: var(--border-strong);
  background: var(--surface-color);
}

.featured-card-col .card-title {
  font-size: clamp(1.8rem, 3.2vw, 2.6rem);
  letter-spacing: -0.03em;
  font-weight: 500;
  line-height: 1.15;
  margin-bottom: 1rem;
  color: var(--text-main);
}

.card-col-half .card-title {
  font-size: clamp(1.4rem, 2.2vw, 1.85rem);
  letter-spacing: -0.025em;
  font-weight: 500;
  line-height: 1.2;
  margin-bottom: 0.85rem;
  color: var(--text-main);
}

.card-excerpt {
  font-size: 1rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 2rem;
  font-weight: 400;
  flex-grow: 1;
}

.card-bottom-row {
  border-top: 1px solid var(--border-color);
  padding-top: 1.25rem;
  margin-top: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* Empty State */
.no-results {
  grid-column: span 12;
  text-align: center;
  padding: 4.5rem 1.5rem;
  background: var(--surface-color);
  border: 1px dashed var(--border-color);
  border-radius: var(--radius-card);
  display: none;
}

.no-results.visible {
  display: block;
}

.no-results h3 {
  font-size: 1.4rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
}

.no-results p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
}

/* ==========================================================================
   SINGLE ARTICLE / PROSE READING VIEW
   ========================================================================== */

.article-header {
  margin-bottom: 3.5rem;
  padding-bottom: 2.25rem;
  border-bottom: 1px solid var(--border-color);
}

.article-header-meta {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  flex-wrap: wrap;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.article-main-title {
  font-size: clamp(2.3rem, 5vw, 3.5rem);
  font-weight: 500;
  letter-spacing: -0.04em;
  line-height: 1.08;
  margin-bottom: 1.25rem;
}

.article-intro-lead {
  font-size: 1.25rem;
  line-height: 1.6;
  color: var(--text-muted);
  font-weight: 400;
}

/* Table of Contents */
.toc-box {
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 1.5rem 1.75rem;
  margin-bottom: 3rem;
}

.toc-title {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 0.85rem;
}

.toc-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.toc-list a {
  font-size: 0.95rem;
  color: var(--text-muted);
  transition: color 0.2s ease, transform 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.toc-list a:hover {
  color: var(--text-main);
  transform: translateX(4px);
}

/* Prose Typography */
.prose {
  font-size: 1.12rem;
  line-height: 1.8;
  color: var(--text-main);
}

.prose p {
  margin-bottom: 1.75rem;
}

.prose h2 {
  font-size: clamp(1.6rem, 3vw, 2.1rem);
  font-weight: 500;
  letter-spacing: -0.03em;
  margin-top: 3.5rem;
  margin-bottom: 1.25rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-color);
}

.prose h3 {
  font-size: 1.35rem;
  font-weight: 500;
  letter-spacing: -0.02em;
  margin-top: 2.25rem;
  margin-bottom: 0.85rem;
}

.prose ul, .prose ol {
  margin: 0 0 1.75rem 1.5rem;
  color: var(--text-muted);
  line-height: 1.75;
}

.prose li {
  margin-bottom: 0.6rem;
}

.prose li strong {
  color: var(--text-main);
}

.prose code:not(pre code) {
  font-family: monospace;
  font-size: 0.9em;
  padding: 0.2em 0.45em;
  border-radius: 6px;
  background: var(--border-color);
  color: var(--text-main);
}

.prose pre {
  background: #0E1117;
  color: #E6EDF3;
  padding: 1.35rem 1.5rem;
  border-radius: 14px;
  overflow-x: auto;
  font-family: "SFMono-Regular", Consolas, Menlo, monospace;
  font-size: 0.92rem;
  line-height: 1.6;
  margin: 1.75rem 0 2.25rem;
  border: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.prose blockquote {
  border-left: 3px solid var(--tech-accent);
  padding: 0.85rem 1.5rem;
  margin: 2rem 0;
  background: var(--surface-color);
  border-radius: 0 14px 14px 0;
  color: var(--text-muted);
  font-style: italic;
  line-height: 1.7;
}

/* Callout Box / Alerts */
.prose-callout {
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 1.5rem;
  margin: 2.25rem 0;
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}

.prose-callout.highlight {
  border-color: rgba(74, 144, 226, 0.35);
  background: rgba(74, 144, 226, 0.04);
}

.callout-icon {
  font-size: 1.3rem;
  flex-shrink: 0;
}

.callout-body h4 {
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  margin-bottom: 0.35rem;
  color: var(--text-main);
}

.callout-body p {
  margin-bottom: 0;
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Diagram / Visual Container */
.diagram-frame {
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 2rem;
  margin: 2.5rem 0;
  overflow-x: auto;
  text-align: center;
}

.diagram-caption {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 600;
  color: var(--text-muted);
  margin-top: 1rem;
}

/* Author Box */
.article-author-card {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 2.25rem;
  border-radius: var(--radius-card);
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  margin-top: 4.5rem;
}

.author-pic {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  overflow: hidden;
  border: 1px solid var(--border-color);
  flex-shrink: 0;
}

.author-pic img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.article-author-card:hover .author-pic img {
  transform: scale(1.04);
}

.author-details h4 {
  font-size: 1.2rem;
  font-weight: 500;
  margin-bottom: 0.25rem;
}

.author-details p {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 0.5rem;
}

.author-links {
  display: flex;
  gap: 1rem;
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.author-links a {
  color: var(--tech-accent);
}

.author-links a:hover {
  text-decoration: underline;
}

/* Read Next / More Articles */
.read-next-section {
  margin-top: 4.5rem;
  padding-top: 3rem;
  border-top: 1px solid var(--border-color);
}

.read-next-section h3 {
  font-size: 1.4rem;
  font-weight: 500;
  margin-bottom: 2rem;
  letter-spacing: -0.02em;
}

/* Blog Footer */
.blog-footer {
  margin-top: auto;
  padding-top: 3.5rem;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.5rem;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 600;
  color: var(--text-muted);
}

.blog-footer-links {
  display: flex;
  gap: 1.5rem;
}

.blog-footer-links a:hover {
  color: var(--text-main);
}