/* Minimalist Webbook Styles */

:root {
  --bg-color: #fdfdfd;
  --text-color: #333;
  --accent-color: #2563eb; /* Blue-600 */
  --nav-bg: #fff;
  --border-color: #e2e8f0;
  --font-serif: Georgia, Cambria, "Times New Roman", Times, serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-serif);
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
  font-size: 1.125rem;
}

/* Navigation */
.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  background-color: var(--nav-bg);
  border-bottom: 1px solid var(--border-color);
  font-family: var(--font-sans);
}

.nav-brand {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-color);
}

.nav-links a {
  text-decoration: none;
  color: var(--text-color);
  margin-left: 1.5rem;
  font-size: 1rem;
}

.nav-links a:hover {
  color: var(--accent-color);
}

.hamburger {
  display: none;
}

/* Main Layout */
main {
  max-width: 800px;
  margin: 0 auto;
  padding: 3rem 1.5rem;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-sans);
  color: #111;
  line-height: 1.3;
}

.book-hero {
  text-align: center;
  margin-bottom: 4rem;
}

.book-title {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 1rem;
}

.book-subtitle {
  font-size: 1.25rem;
  color: #555;
  font-weight: 400;
  max-width: 600px;
  margin: 0 auto;
}

p {
  margin-bottom: 1.5rem;
}

/* Table of Contents */
.toc {
  background: #f8fafc;
  padding: 2rem;
  border-radius: 8px;
  border: 1px solid var(--border-color);
}

.toc h2 {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
}

.toc ol {
  list-style-type: none;
  padding-left: 0;
}

.toc > ol > li {
  margin-bottom: 0.75rem;
  font-weight: 600;
}

.toc > ol > li > ol {
  padding-left: 1.5rem;
  margin-top: 0.5rem;
  margin-bottom: 1rem;
}

.toc > ol > li > ol > li {
  font-weight: 400;
  margin-bottom: 0.5rem;
}

a {
  color: var(--accent-color);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

footer {
  text-align: center;
  padding: 2rem;
  border-top: 1px solid var(--border-color);
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: #666;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
  .book-title {
    font-size: 2rem;
  }
  
  .navbar {
    padding: 1rem;
  }

  .nav-links {
    display: flex; /* Simplified for now, keep visible on mobile or handle appropriately */
  }
}