@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Source+Serif+4:opsz,wght@8..60,600;8..60,700&display=swap');

:root {
  --blog-accent: #007AFF;
  --blog-text: #111827;
  --blog-muted: #6b7280;
  --blog-bg: #fafafa;
  --blog-border: #e5e7eb;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: Inter, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--blog-bg);
  color: var(--blog-text);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--blog-accent); text-decoration: none; }
a:hover { color: #0056CC; }

.blog-layout {
  max-width: 80rem;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

.blog-grid {
  display: grid;
  gap: 2.5rem;
}

@media (min-width: 1024px) {
  .blog-grid {
    grid-template-columns: 220px minmax(0, 1fr);
    gap: 4rem;
  }
}

.blog-header-bar {
  border-bottom: 1px solid var(--blog-border);
  background: var(--blog-bg);
}

.blog-header-inner {
  max-width: 80rem;
  margin: 0 auto;
  padding: 1.25rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

.blog-back {
  color: var(--blog-muted);
  font-size: 0.875rem;
  font-weight: 500;
}

.blog-breadcrumb {
  display: none;
  gap: 0.5rem;
  color: #9ca3af;
  font-size: 0.875rem;
}

@media (min-width: 640px) {
  .blog-breadcrumb { display: flex; align-items: center; }
}

.blog-toc {
  display: none;
  position: sticky;
  top: 7rem;
  align-self: start;
  border: 1px solid var(--blog-border);
  border-radius: 1rem;
  background: #fff;
  padding: 1.25rem;
}

@media (min-width: 1024px) {
  .blog-toc { display: block; }
}

.blog-toc h3 {
  margin: 0 0 1rem;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--blog-muted);
}

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

.blog-toc li { margin-bottom: 0.25rem; }

.blog-toc a {
  display: block;
  padding: 0.5rem 0.75rem;
  border-radius: 0.5rem;
  color: #4b5563;
  font-size: 0.875rem;
}

.blog-toc a:hover {
  background: rgba(0, 122, 255, 0.08);
  color: var(--blog-accent);
}

.blog-article-header {
  max-width: 48rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--blog-border);
}

.blog-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1rem;
  color: var(--blog-muted);
  font-size: 0.875rem;
}

.blog-title {
  font-size: clamp(1.75rem, 3.5vw, 3rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: 1.25rem 0 0;
}

.blog-excerpt {
  margin-top: 1rem;
  max-width: 42rem;
  color: #4b5563;
  font-size: 1rem;
  line-height: 1.7;
}

.blog-prose {
  max-width: 42rem;
  margin-top: 2rem;
  font-size: clamp(1rem, 1.1vw, 1.125rem);
  line-height: 1.7;
  color: #374151;
}

.blog-prose h2 {
  font-size: clamp(1.375rem, 2vw, 1.75rem);
  line-height: 1.25;
  margin: 2.5rem 0 1rem;
  color: var(--blog-text);
}

.blog-prose h3 {
  font-size: clamp(1.0625rem, 1.5vw, 1.25rem);
  line-height: 1.35;
  margin: 2rem 0 0.75rem;
  color: var(--blog-text);
}

.blog-prose p { margin: 0 0 0.5rem; }
.blog-prose p + p { margin-top: 0; }
.blog-prose p + h2,
.blog-prose p + h3,
.blog-prose ul + h2,
.blog-prose ol + h2 { margin-top: 2.25rem; }
.blog-prose h2 + p,
.blog-prose h3 + p { margin-top: 0.75rem; }

.blog-prose ul,
.blog-prose ol {
  margin: 0 0 1.5rem;
  padding-left: 1.25rem;
}

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

.blog-prose blockquote {
  margin: 1.5rem 0;
  padding: 1rem 1.25rem;
  border-left: 4px solid var(--blog-accent);
  background: #f9fafb;
  color: #374151;
}

.blog-prose pre {
  overflow-x: auto;
  margin: 1.5rem 0;
  padding: 1rem;
  border-radius: 0.75rem;
  background: #111827;
  color: #f3f4f6;
  font-size: 0.875rem;
}

.blog-prose code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}

.blog-prose :not(pre) > code {
  padding: 0.125rem 0.375rem;
  border-radius: 0.25rem;
  background: #f3f4f6;
  font-size: 0.875rem;
}

.blog-prose img {
  max-width: 100%;
  border-radius: 0.75rem;
  border: 1px solid var(--blog-border);
}

.blog-prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.875rem;
}

.blog-prose th,
.blog-prose td {
  border: 1px solid var(--blog-border);
  padding: 0.75rem 1rem;
  text-align: left;
}

.blog-prose th {
  background: #f9fafb;
  font-weight: 600;
}

.blog-cta {
  max-width: 48rem;
  margin-top: 3rem;
  padding: 2rem;
  border: 1px solid var(--blog-border);
  border-radius: 1rem;
  background: #fff;
}

.blog-cta h2 {
  margin: 0;
  font-size: 1.25rem;
}

.blog-cta p {
  margin: 0.75rem 0 0;
  color: #4b5563;
}

.blog-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.blog-btn-primary,
.blog-btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.25rem;
  border-radius: 0.75rem;
  font-size: 0.875rem;
  font-weight: 600;
}

.blog-btn-primary {
  background: var(--blog-accent);
  color: #fff;
}

.blog-btn-secondary {
  border: 1px solid var(--blog-border);
  color: #374151;
  background: #fff;
}

.blog-list-item {
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--blog-border);
}

.blog-list-item h2 {
  margin: 0;
  font-size: 1.125rem;
  line-height: 1.3;
}

.blog-list-item p {
  margin: 0.5rem 0 0;
  color: #4b5563;
  font-size: 0.875rem;
  line-height: 1.6;
}

.blog-list-meta {
  margin-top: 0.75rem;
  color: var(--blog-muted);
  font-size: 0.875rem;
}

.blog-pagination {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--blog-border);
  color: var(--blog-muted);
  font-size: 0.875rem;
}

.blog-pagination a {
  font-weight: 600;
}

.blog-related {
  max-width: 48rem;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--blog-border);
}

.blog-related h2 {
  margin: 0;
  color: var(--blog-text);
  font-size: 1.25rem;
}

.blog-related-list {
  display: grid;
  gap: 1rem;
  margin-top: 1rem;
}

.blog-related article {
  padding: 1rem 0;
  border-bottom: 1px solid var(--blog-border);
}

.blog-related h3 {
  margin: 0;
  font-size: 1rem;
  line-height: 1.4;
}

.blog-related p {
  margin: 0.4rem 0 0;
  color: #4b5563;
  font-size: 0.875rem;
  line-height: 1.6;
}

.blog-related span {
  display: block;
  margin-top: 0.5rem;
  color: var(--blog-muted);
  font-size: 0.8125rem;
}

.blog-archive-header {
  max-width: 48rem;
  margin-bottom: 2rem;
}

.blog-archive-year {
  max-width: 56rem;
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--blog-border);
}

.blog-archive-year h2 {
  margin: 0 0 1rem;
  color: var(--blog-text);
  font-size: 1.375rem;
}

.blog-archive-year ol {
  display: grid;
  gap: 0.875rem;
  margin: 0;
  padding-left: 1.25rem;
}

.blog-archive-year li {
  padding-left: 0.25rem;
}

.blog-archive-year li > a {
  font-weight: 600;
}

.blog-archive-year span {
  display: block;
  margin-top: 0.25rem;
  color: var(--blog-muted);
  font-size: 0.8125rem;
}

.blog-category-title {
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.15;
  margin: 0.75rem 0 0;
}

.blog-category-desc {
  margin-top: 0.75rem;
  max-width: 42rem;
  color: #4b5563;
}

.blog-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  width: 0;
  background: var(--blog-accent);
  z-index: 50;
}