/* NGI Tech Blog - Stylesheet */
/* Accent Color: #313e8b (Deep Blue) */

:root {
  --accent-color: #313e8b;
  --accent-hover: #252f6b;
  --text-primary: #333333;
  --text-secondary: #666666;
  --border-color: #e0e0e0;
  --background-white: #ffffff;
  --background-light: #f8f9fa;
}

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

body {
  font-family:
    -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--background-white);
}

/* Header */
header {
  background-color: var(--background-white);
  padding: 0.75rem 0;
  border-bottom: 1px solid #e8e8e8;
}

header .container {
  padding: 0 2rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

header .logo {
  height: 32px;
  width: auto;
}

header .company-link {
  margin-left: auto;
  font-weight: 700;
  font-size: 0.9rem;
  color: #bbb;
  text-decoration: none;
  transition: color 0.2s;
}

header .company-link:hover {
  color: #888;
}

header h1 {
  color: var(--accent-color);
  font-size: 1.25rem;
  font-weight: 600;
}

header h1 a {
  color: var(--accent-color);
  text-decoration: none;
  transition: opacity 0.2s;
  display: flex;
  align-items: center;
  gap: 1rem;
}

header h1 a:hover {
  opacity: 0.7;
}

header p {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* Main Container */
.container {
  width: 100%;
  padding: 0 2rem;
}

.main-container {
  display: flex;
  padding: 0 2rem;
  gap: 2rem;
}

main {
  padding: 1.5rem 0;
  min-height: calc(100vh - 200px);
  flex: 1;
  min-width: 0;
}

.sidebar {
  width: 280px;
  padding: 1.5rem 0;
  flex-shrink: 0;
}

.nav-section {
  margin-bottom: 2rem;
}

.nav-section h3 {
  font-size: 1rem;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid #e8e8e8;
}

.nav-section ul {
  list-style: none;
}

.nav-section ul li a {
  display: block;
  color: var(--text-secondary);
  text-decoration: none;
  padding: 0.5rem 0;
  font-size: 0.95rem;
  transition: color 0.2s;
}

.nav-section ul li a:hover {
  color: var(--accent-color);
}

#category-list li {
  cursor: pointer;
  padding: 0.5rem 0;
  color: var(--text-secondary);
  font-size: 0.95rem;
  transition: color 0.2s;
}

#category-list li:hover {
  color: var(--accent-color);
}

#category-list li a {
  padding: 0;
  display: inline;
  color: inherit;
  font-size: inherit;
}

#category-list li.active {
  color: var(--accent-color);
  font-weight: 600;
}

/* Article List (Index Page) */
.article-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-top: 2rem;
}

.article-card {
  background-color: var(--background-white);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.25rem;
  transition:
    box-shadow 0.3s,
    transform 0.2s;
  text-decoration: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.article-card:hover {
  box-shadow: 0 4px 12px rgba(49, 62, 139, 0.15);
  transform: translateY(-2px);
}

.article-card h2 {
  color: var(--accent-color);
  font-size: 1.1rem;
  line-height: 1.4;
}

.article-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.85rem;
}

.article-excerpt {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.7;
  flex: 1;
}

.read-more {
  display: inline-block;
  margin-top: 0.25rem;
  color: var(--accent-color);
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}

.read-more:hover {
  border-bottom-color: var(--accent-color);
}

/* Article Layout */
.article-layout {
  display: flex;
  gap: 3rem;
  position: relative;
}

/* Article Content */
#article-contents {
  flex: 1;
  min-width: 0;
  padding: 2rem 0;
}

/* Progress Navigation */
.progress-nav {
  position: sticky;
  top: 2rem;
  width: 250px;
  max-height: calc(100vh - 4rem);
  overflow-y: auto;
  padding: 1.5rem;
  background-color: var(--background-light);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  flex-shrink: 0;
}

.progress-nav-header {
  font-size: 1rem;
  font-weight: 700;
  color: var(--accent-color);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--accent-color);
}

.progress-nav-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.progress-nav-list li {
  margin-bottom: 0;
}

.progress-nav-list a {
  display: block;
  padding: 0.5rem 0;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  line-height: 1.4;
  border-left: 2px solid transparent;
  padding-left: 0.75rem;
  transition: all 0.2s;
}

.progress-nav-list a:hover {
  color: var(--accent-color);
  border-left-color: var(--accent-color);
}

.progress-nav-list a.active {
  color: var(--accent-color);
  font-weight: 600;
  border-left-color: var(--accent-color);
  background-color: rgba(49, 62, 139, 0.05);
}

.progress-nav-list .nav-h3 {
  padding-left: 1.5rem;
  font-size: 0.85rem;
}

/* Article Metadata */
.article-meta-info {
  margin-bottom: 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.author-info {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.author-label {
  color: var(--text-secondary);
}

.author-name {
  font-weight: 700;
  color: var(--accent-color);
}

.author-details {
  color: var(--accent-color);
}

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

.publish-date {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

#article-contents h1 {
  color: var(--accent-color);
  font-size: 2.25rem;
  margin-bottom: 1.5rem;
  line-height: 1.3;
}

#article-contents h2 {
  color: var(--accent-color);
  font-size: 1.75rem;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--border-color);
}

#article-contents h3 {
  color: var(--text-primary);
  font-size: 1.35rem;
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

#article-contents h4 {
  color: var(--text-primary);
  font-size: 1.15rem;
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
}

#article-contents p {
  margin-bottom: 1.25rem;
  line-height: 1.8;
}

#article-contents a {
  color: var(--accent-color);
  text-decoration: none;
  border-bottom: 1px solid var(--accent-color);
  transition: opacity 0.2s;
}

#article-contents a:hover {
  opacity: 0.7;
}

#article-contents img {
  max-width: 100%;
  height: auto;
  margin: 2rem 0;
  border-radius: 4px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

#article-contents ul,
#article-contents ol {
  margin-bottom: 1.25rem;
  padding-left: 2rem;
}

#article-contents li {
  margin-bottom: 0.5rem;
  line-height: 1.7;
}

#article-contents code {
  background-color: var(--background-light);
  padding: 0.2rem 0.4rem;
  border-radius: 3px;
  font-family: 'Consolas, Monaco', 'Lucida Console', monospace;
  font-size: 0.9em;
  color: var(--text-primary);
}

#article-contents pre {
  background-color: var(--background-light);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  padding: 1.25rem;
  overflow-x: auto;
  margin-bottom: 1.5rem;
}

#article-contents pre code {
  background-color: transparent;
  padding: 0;
  font-size: 0.9rem;
}

#article-contents blockquote {
  border-left: 4px solid var(--accent-color);
  padding-left: 1.5rem;
  margin: 1.5rem 0;
  color: var(--text-secondary);
  font-style: italic;
}

#article-contents table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
}

#article-contents th,
#article-contents td {
  border: 1px solid var(--border-color);
  padding: 0.75rem;
  text-align: left;
}

#article-contents th {
  background-color: var(--accent-color);
  color: white;
  font-weight: 600;
}

#article-contents tr:nth-child(even) {
  background-color: var(--background-light);
}

/* Back to Top Link */
.back-to-top {
  display: inline-block;
  margin-top: 3rem;
  padding: 0.75rem 1.5rem;
  background-color: var(--accent-color);
  color: white;
  text-decoration: none;
  border-radius: 4px;
  transition: background-color 0.2s;
  font-weight: 500;
}

.back-to-top:hover {
  background-color: var(--accent-hover);
}

/* Footer */
footer {
  background-color: var(--background-white);
  border-top: 1px solid #e8e8e8;
  padding: 1.5rem 0;
  margin-top: 3rem;
}

footer .container {
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 1024px) {
  .progress-nav,
  .sidebar {
    display: none;
  }

  .article-layout {
    display: block;
  }

  .main-container {
    padding: 0 1.5rem;
  }
}

@media (max-width: 768px) {
  header h1 {
    font-size: 1rem;
  }

  .container,
  .main-container {
    padding: 0 1rem;
  }

  main {
    padding: 1rem 0;
  }

  .article-list {
    grid-template-columns: 1fr;
  }

  header .company-link {
    display: none;
  }

  header .logo {
    height: auto;
    max-height: 32px;
    max-width: 50%;
  }

  #article-contents h1 {
    font-size: 1.75rem;
  }

  #article-contents h2 {
    font-size: 1.5rem;
  }

  #article-contents {
    padding: 1rem 0;
  }
}

.category-badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 600;
  background-color: #e0e0e0;
  color: #333;
  text-decoration: none;
}

a.category-badge:hover {
  background-color: #d0d0d0;
}