:root {
  --bg-color: #fdfdfd;
  --text-color: #1a1a1a;
  --accent-color: #d44c2c;
  --muted-color: #666;
  --border-color: #eee;
  --font-sans: 'Inter', sans-serif;
  --font-serif: 'Playfair Display', serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: var(--font-sans);
  line-height: 1.6;
}

.wrapper {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 20px;
}

.site-header {
  border-bottom: 1px solid var(--border-color);
  padding: 40px 0;
}

.site-title {
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: 2.5rem;
  color: var(--text-color);
  text-decoration: none;
  letter-spacing: -1px;
}

.page-content {
  padding: 60px 0;
}

/* Home Portal Styles */
.hero {
  margin-bottom: 80px;
}

.hero h1 {
  font-family: var(--font-serif);
  font-size: 4rem;
  line-height: 1.1;
  margin-bottom: 20px;
}

.hero p {
  font-size: 1.5rem;
  color: var(--muted-color);
  max-width: 600px;
}

.books-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 40px;
}

.book-card {
  border: 1px solid var(--border-color);
  padding: 30px;
  transition: transform 0.2s ease, border-color 0.2s ease;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
}

.book-card:hover {
  transform: translateY(-5px);
  border-color: var(--accent-color);
}

.book-card h3 {
  font-family: var(--font-serif);
  font-size: 1.8rem;
  margin: 0 0 15px 0;
}

.book-card .meta {
  font-size: 0.9rem;
  color: var(--muted-color);
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* Book Layout Styles */
.post-header {
  margin-bottom: 60px;
}

.post-title {
  font-family: var(--font-serif);
  font-size: 3.5rem;
  margin-bottom: 10px;
}

.post-meta {
  color: var(--muted-color);
  font-weight: 600;
}

.post-content {
  font-size: 1.25rem;
  line-height: 1.8;
}

.post-content h2 {
  margin-top: 50px;
  font-family: var(--font-serif);
}

.language-switcher {
  margin-top: 80px;
  padding-top: 40px;
  border-top: 1px solid var(--border-color);
}

.language-switcher ul {
  list-style: none;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
}

.language-switcher a {
  display: inline-block;
  padding: 8px 16px;
  background: #f0f0f0;
  border-radius: 4px;
  text-decoration: none;
  color: var(--text-color);
  font-size: 0.9rem;
  font-weight: 600;
}

.language-switcher a:hover {
  background: var(--accent-color);
  color: white;
}

.site-footer {
  padding: 60px 0;
  border-top: 1px solid var(--border-color);
  font-size: 0.9rem;
  color: var(--muted-color);
  text-align: center;
}

/* Portal Nodes and Interactive Elements */
.portal-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin-top: 40px;
}

.portal-node {
  background: white;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  overflow: hidden;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.portal-node.active {
  border-color: var(--accent-color);
  box-shadow: 0 10px 30px rgba(0,0,0,0.05);
}

.portal-node-header {
  padding: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  user-select: none;
}

.portal-node-header h2 {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 1.5rem;
}

.portal-node-icon {
  width: 24px;
  height: 24px;
  transition: transform 0.3s ease;
}

.portal-node.active .portal-node-icon {
  transform: rotate(180deg);
}

.portal-node-content {
  max-height: 0;
  padding: 0 24px;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
}

.portal-node.active .portal-node-content {
  max-height: 2000px;
  padding: 0 24px 30px 24px;
}

.diagnostic-tool {
  background: #f9f9f9;
  border: 1px dashed var(--muted-color);
  padding: 40px;
  border-radius: 8px;
  margin-top: 20px;
  text-align: center;
}

.diagnostic-tool input, .diagnostic-tool textarea {
  width: 100%;
  padding: 15px;
  margin: 10px 0;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  font-family: var(--font-sans);
}

.btn-primary {
  background: var(--accent-color);
  color: white;
  border: none;
  padding: 12px 30px;
  font-weight: 800;
  border-radius: 4px;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 1px;
}