:root {
  --primary-color: #494e52;
  --accent-color: #52adc8;
  --link-color: #1a0dab;
  --link-hover: #52adc8;
  --text-color: #3d4144;
  --text-muted: #6c757d;
  --bg-color: #fff;
  --sidebar-bg: #fafafa;
  --border-color: #e0e0e0;
  --masthead-bg: #fff;
  --footer-bg: #f8f9fa;
  --font-sans: 'Source Sans 3', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-serif: 'Libre Baskerville', Georgia, 'Times New Roman', serif;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 20px;
  line-height: 1.65;
  color: var(--text-color);
  background: var(--bg-color);
}

a {
  color: var(--link-color);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--link-hover);
  text-decoration: underline;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-sans);
  font-weight: 600;
  color: var(--primary-color);
  margin-top: 2rem;
  margin-bottom: 1rem;
  line-height: 1.25;
}

h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; border-bottom: 1px solid var(--border-color); padding-bottom: 0.5rem; }
h3 { font-size: 1.25rem; }

p {
  margin: 0 0 1.25rem;
}

ul, ol {
  padding-left: 1.5rem;
  margin-bottom: 1.5rem;
}

li {
  margin-bottom: 0.5rem;
}

.masthead {
  background: var(--masthead-bg);
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.masthead__inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.site-title {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-color);
  text-decoration: none;
}

.site-title:hover {
  color: var(--accent-color);
  text-decoration: none;
}

.nav__list {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: 2rem;
}

.nav__link {
  color: var(--text-muted);
  font-weight: 600;
  text-transform: uppercase;
  font-size: 0.85rem;
  letter-spacing: 0.05em;
  padding: 0.25rem 0;
  border-bottom: 2px solid transparent;
  transition: all 0.2s ease;
}

.nav__link:hover,
.nav__link.active {
  color: var(--primary-color);
  text-decoration: none;
  border-bottom-color: var(--accent-color);
}

.page-wrapper {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 3rem;
}

.sidebar {
  position: sticky;
  top: 100px;
  height: fit-content;
}

.author-profile {
  text-align: center;
  padding: 1.5rem;
  background: var(--sidebar-bg);
  border-radius: 8px;
}

.author-avatar img {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--border-color);
  margin-bottom: 1rem;
}

.author-name {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  margin: 0 0 0.5rem;
  color: var(--primary-color);
}

.author-bio {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
  line-height: 1.5;
}

.follow-btn {
  background: var(--accent-color);
  color: #fff;
  border: none;
  padding: 0.5rem 1.5rem;
  border-radius: 4px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s ease;
  margin-bottom: 1.5rem;
}

.follow-btn:hover {
  background: #3d8fa8;
}

.author-links {
  list-style: none;
  padding: 0;
  margin: 0;
  text-align: left;
}

.author-links li {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0;
  font-size: 0.9rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-color);
}

.author-links li:first-child {
  border-top: none;
}

.author-links svg {
  flex-shrink: 0;
  color: var(--text-muted);
}

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

.content {
  min-width: 0;
}

.content h1:first-child {
  margin-top: 0;
}

.content ul li {
  margin-bottom: 0.75rem;
}

.content ul li ul {
  margin-top: 0.5rem;
  margin-bottom: 0;
}

.content ul li ul li {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer {
  background: var(--footer-bg);
  border-top: 1px solid var(--border-color);
  padding: 2rem 0;
  margin-top: 3rem;
}

.footer__inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer__links {
  margin-bottom: 1rem;
}

.footer__links a {
  margin-left: 0.5rem;
}

.footer p {
  margin: 0;
}

@media (max-width: 768px) {
  .masthead__inner {
    flex-direction: column;
    gap: 1rem;
  }
  
  .nav__list {
    gap: 1rem;
  }
  
  .page-wrapper {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  
  .sidebar {
    position: static;
    order: -1;
  }
  
  .author-profile {
    max-width: 300px;
    margin: 0 auto;
  }
}

strong {
  font-weight: 600;
}

em {
  font-style: italic;
}