style.css

/* Basic Quarto code styling */
p.caption {
  color: #777;
  margin-top: 10px;
}
p code {
  white-space: inherit;
}
pre {
  word-break: normal;
  word-wrap: normal;
}
pre code {
  white-space: inherit;
}

/* Code typography (match older bookdown look: smaller + clearer) */
pre,
pre code,
.sourceCode {
  font-family: "Source Code Pro", ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
    "Liberation Mono", "Courier New", monospace;
  font-size: 0.95em;
  line-height: 1.55;
}

/* Reset default margins and padding */
body {
  margin: 0;
  padding: 0;
  font-family: "Source Sans Pro", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

/* Custom layout container with CSS Grid */
.page-layout-custom {
  display: grid;
  grid-template-columns: 300px 1fr;
  min-height: 100vh;
  margin: 0;
  padding: 0;
}

/* Sidebar styling - fixed 300px width, sticky position */
.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  background: linear-gradient(180deg, #f8f9fa 0%, #f1f3f4 100%);
  border-right: 1px solid #dee2e6;
  box-shadow: 2px 0 12px rgba(0,0,0,0.08);
  z-index: 1000;
}




/* Hide collapse/expand buttons for parts */
.sidebar-item.part .sidebar-item-toggle,
.sidebar-item-section .sidebar-item-toggle,
.sidebar-part .sidebar-item-toggle {
  display: none !important;
}

/* Ensure part sections are always expanded */
.sidebar-item.part .sidebar-item-container,
.sidebar-item-section .sidebar-item-container {
  display: block !important;
}

/* Style the sidebar 'part' headings - Professional section headers */
.sidebar-item-section > .sidebar-item-container > .sidebar-item-text,
.sidebar-item.part,
.sidebar-part,
.sidebar-section-title {
  color: #2d3748 !important;
  font-weight: 600;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-top: 1.5rem;
  margin-bottom: 0.8rem;
  padding: 0.8rem 0;
  background: none;
  border: none;
  border-bottom: 2px solid #e2e8f0;
  box-shadow: none;
  pointer-events: none;
  position: relative;
}

.sidebar-item-section > .sidebar-item-container > .sidebar-item-text::after,
.sidebar-item.part::after,
.sidebar-part::after,
.sidebar-section-title::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 40px;
  height: 2px;
  background: linear-gradient(90deg, #6b7280 0%, #9ca3af 100%);
}

/* Chapter/page links styling - Professional gray links */
.sidebar-item {
  border-radius: 0;
  margin: 0;
  transition: all 0.3s ease;
  position: relative;
}

.sidebar-item .sidebar-item-text {
  color: #4b5563;
  font-weight: 400;
  padding: 0.6rem 0;
  border-radius: 0;
  transition: all 0.3s ease;
  display: block;
  border-left: none;
  background: none;
  text-decoration: none;
  position: relative;
  font-size: 0.95rem;
  line-height: 1.4;
}

.sidebar-item .sidebar-item-text:hover {
  background-color: transparent;
  color: #1f2937;
  border-left: none;
  transform: translateX(3px);
  box-shadow: none;
  text-decoration: none;
}

/* Active page styling - Professional gray accent */
.sidebar-item .sidebar-item-text.active {
  background: none !important;
  color: #111827 !important;
  font-weight: 600 !important;
  border-left: 3px solid #51555c !important;
  box-shadow: none !important;
  transform: translateX(0px);
  padding-left: 0.5rem;
}

/* Override any blue active states */
.sidebar-item .sidebar-item-text.active,
.sidebar-item.active .sidebar-item-text,
.sidebar-item .sidebar-item-text[aria-current],
.sidebar-item .sidebar-item-text[aria-current="page"] {
  background: none !important;
  color: #111827 !important;
  font-weight: 600 !important;
  border-left: 3px solid #4b5563 !important;
  border-color: #4b5563 !important;
  box-shadow: none !important;
}

/* Nested items (subsections) - Refined hierarchy */
.sidebar-item .sidebar-item .sidebar-item-text {
  padding-left: 1.5rem;
  font-size: 0.87rem;
  font-weight: 400;
  color: #9ca3af;
  border-left: none;
  background-color: transparent;
  position: relative;
}

.sidebar-item .sidebar-item .sidebar-item-text:hover {
  border-left: none;
  background-color: transparent;
  color: #6b7280;
  transform: translateX(2px);
}

/* Professional content link styling - Override all blue links */
a {
  color: #4b5563 !important;
  text-decoration: none !important;
}

a:hover {
  color: #1f2937 !important;
  text-decoration: underline !important;
}

a:visited {
  color: #6b7280 !important;
}

/* More specific targeting for content areas */
main.content a,
.content a,
article a,
.page-layout-body a,
#quarto-content a,
.quarto-container a {
  color: #444951 !important;
  text-decoration: none !important;
  font-weight: 500;
  transition: all 0.2s ease;
}

main.content a:hover,
.content a:hover,
article a:hover,
.page-layout-body a:hover,
#quarto-content a:hover,
.quarto-container a:hover {
  color: #1f2937 !important;
  text-decoration: underline !important;
}

main.content a:visited,
.content a:visited,
article a:visited,
.page-layout-body a:visited,
#quarto-content a:visited,
.quarto-container a:visited {
  color: #6b7280 !important;
}

/* Code links should remain distinct */
code a,
pre a {
  color: inherit !important;
  text-decoration: none !important;
}

/* Section dividers - Subtle spacing */
.sidebar-item-section {
  margin-top: 0.5rem;
  margin-bottom: 0.5rem;
  padding-top: 0;
  border-top: none;
}

.sidebar-item-section:first-child {
  border-top: none;
  padding-top: 0;
}

/* Elegant scrollbar styling for sidebar */
.sidebar-navigation::-webkit-scrollbar {
  width: 5px;
}

.sidebar-navigation::-webkit-scrollbar-track {
  background: rgba(0,0,0,0.05);
  border-radius: 3px;
}

.sidebar-navigation::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, #9ca3af 0%, #6b7280 100%);
  border-radius: 3px;
}

.sidebar-navigation::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(180deg, #6b7280 0%, #4b5563 100%);
}

/* Responsive design for mobile devices */
@media (max-width: 768px) {
  .page-layout-custom {
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr;
  }
  
  .sidebar {
    position: relative;
    height: auto;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    border-right: none;
    border-bottom: 1px solid #dee2e6;
  }
  
  .main-content {
    grid-template-columns: 0.5fr 4fr 0.5fr;
    padding: 1rem 0;
  }
  
  .content-center {
    padding: 1rem;
  }
  
  .sidebar-item .sidebar-item-text {
    padding: 0.5rem 0;
    font-size: 0.9rem;
  }
  
  .sidebar-navigation {
    padding: 1rem 0.8rem;
  }
}

/* Additional responsive breakpoint for tablets */
@media (min-width: 769px) and (max-width: 1024px) {
  .main-content {
    grid-template-columns: 0.5fr 4fr 0.5fr;
  }
}

/* Large screens - maintain the 1/5, 3/5, 1/5 ratio */
@media (min-width: 1200px) {
  .main-content {
    grid-template-columns: 1fr 3fr 1fr;
  }
  
  .content-center {
    padding: 3rem;
  }
}



/* Callout Box Styles */
.callout-box {
  border-left: 4px solid #007acc;
  background-color: #f5f8fa;
  padding: 1em 1.2em;
  margin: 1.5em 0;
  border-radius: 4px;
  font-size: 0.95em;
  line-height: 1.6;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

/* Optional modifier for info-type callouts */
.callout-box.info {
  border-color: #007acc;
  background-color: #f0f8ff;
}