.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  border: 1px solid transparent;
  font-size: 1rem;
  text-align: center;
  line-height: 1.5;
}

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

.btn-primary {
  background-color: var(--primary-color);
  color: white;
  box-shadow: 0 1px 2px rgba(0,0,0,0.05);
}

.btn-primary:hover { background-color: var(--primary-hover); text-decoration: none; color: white; transform: translateY(-1px); box-shadow: 0 4px 6px rgba(0,0,0,0.1); }

.btn-outline {
  background-color: transparent;
  border-color: var(--border-color);
  color: var(--text-color);
}

.btn-outline:hover { background-color: var(--bg-color); text-decoration: none; }

.card {
  background: var(--bg-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 2rem;
  border: 1px solid var(--border-color);
  transition: box-shadow 0.2s ease;
}

.card:hover { box-shadow: var(--shadow-lg); }

.hero {
  text-align: center;
  padding: 6rem 1rem 5rem;
  background: linear-gradient(to bottom, #eff6ff 0%, #f9fafb 100%);
  border-bottom: 1px solid var(--border-color);
}

.hero h1 { font-size: 3rem; font-weight: 800; margin-bottom: 1.25rem; letter-spacing: -0.025em; color: #1e3a8a;}
.hero p { font-size: 1.25rem; color: var(--text-light); max-width: 700px; margin: 0 auto 2.5rem; line-height: 1.6; }

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 2rem;
  color: var(--text-light);
  font-size: 0.875rem;
}

.breadcrumb a { color: var(--text-light); }
.breadcrumb a:hover { color: var(--primary-color); }
.breadcrumb span { color: var(--text-lighter); }

.prose { margin: 0 auto; }
.prose h1 { font-size: 2.5rem; margin-bottom: 1.5rem; letter-spacing: -0.025em; }
.prose h2 { font-size: 1.875rem; margin-top: 3rem; margin-bottom: 1.25rem; }
.prose h3 { font-size: 1.5rem; margin-top: 2rem; margin-bottom: 1rem; }
.prose p { margin-bottom: 1.5rem; }
.prose ul, .prose ol { margin-bottom: 1.5rem; padding-left: 1.5rem; }
.prose li { margin-bottom: 0.5rem; }
.prose strong { color: #111827; }

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  color: var(--text-light);
  font-size: 0.875rem;
  margin-bottom: 2.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-color);
}

.article-meta span { display: flex; align-items: center; gap: 0.5rem; }

.toc {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 3rem;
}

.toc h2 { font-size: 1.25rem; margin-top: 0; margin-bottom: 1rem; }
.toc ul { list-style: none; padding-left: 0; margin: 0; }
.toc li { margin-bottom: 0.5rem; }
.toc a { color: var(--text-color); font-weight: 500; display: block; padding: 0.25rem 0;}
.toc a:hover { color: var(--primary-color); }
.toc ul ul { padding-left: 1rem; margin-top: 0.5rem; }
.toc ul ul a { font-weight: 400; font-size: 0.95em; color: var(--text-light); }

.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
  margin-top: 3rem;
}

.blog-card {
  display: flex;
  flex-direction: column;
  height: 100%;
}

.blog-card .card-content { flex-grow: 1; display: flex; flex-direction: column; }
.blog-card .category { color: var(--primary-color); font-weight: 600; font-size: 0.875rem; margin-bottom: 0.5rem; text-transform: uppercase; letter-spacing: 0.05em; }
.blog-card h3 { margin-bottom: 1rem; font-size: 1.25rem; }
.blog-card p { color: var(--text-light); flex-grow: 1; margin-bottom: 1.5rem; }
.blog-card .meta { display: flex; justify-content: space-between; align-items: center; color: var(--text-lighter); font-size: 0.875rem; border-top: 1px solid var(--border-color); padding-top: 1rem;}

.cta-box {
  background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
  border: 1px solid #bfdbfe;
  border-radius: var(--radius);
  padding: 3rem 2rem;
  text-align: center;
  margin: 4rem 0;
}
.cta-box h2 { color: #1e3a8a; font-size: 2rem; margin-bottom: 1rem; }
.cta-box p { color: #1e40af; font-size: 1.125rem; margin-bottom: 2rem; max-width: 600px; margin-left: auto; margin-right: auto; }

@media (max-width: 768px) {
  .hero { padding: 4rem 1rem 3rem; }
  .hero h1 { font-size: 2.25rem; }
  .prose h1 { font-size: 2rem; }
}