uncloseai.com/css/sidebar-theme.css

/* CSS Grid-based sidebar navigation theme for PicoCSS */

:root {
  --sidebar-width: 280px;
  --content-max-width: 1200px;
  --base-font-size: 16px;
  --heading-scale: 1.125;
}

/* Adjust default font sizes */
html {
  font-size: var(--base-font-size);
}

body {
  font-size: 1rem;
  line-height: 1.6;
}

h1 { font-size: calc(1rem * var(--heading-scale) * var(--heading-scale) * var(--heading-scale) * var(--heading-scale)); }
h2 { font-size: calc(1rem * var(--heading-scale) * var(--heading-scale) * var(--heading-scale)); }
h3 { font-size: calc(1rem * var(--heading-scale) * var(--heading-scale)); }
h4 { font-size: calc(1rem * var(--heading-scale)); }
h5, h6 { font-size: 1rem; }

/* Main grid layout */
body {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  grid-template-areas: 
    "sidebar main";
  gap: 2rem;
  min-height: 100vh;
  margin: 0;
  padding: 1rem;
  /* Ensure body doesn't expand beyond viewport */
  max-width: 100vw;
  overflow-x: auto;
}

/* Sidebar navigation */
aside.sidebar {
  grid-area: sidebar;
  background: var(--card-background-color);
  border-right: 1px solid var(--muted-border-color);
  padding: 2rem;
  position: sticky;
  top: 1rem;
  height: calc(100vh - 2rem);
  overflow-y: auto;
  overflow-x: hidden;
  border-radius: 0.5rem;
}

/* Main content area */
main {
  grid-area: main;
  padding: 2rem;
  max-width: 960px !important;
  margin: 0 auto;
  /* Prevent content overflow */
  overflow-x: auto;
  overflow-y: visible;
}

/* Responsive main content */
@media (min-width: 769px) and (max-width: 1024px) {
  main {
    max-width: 100% !important;
    margin-right: 2rem;
  }
}

@media (min-width: 1025px) and (max-width: 1440px) {
  main {
    max-width: 900px !important;
    margin-right: 3rem;
  }
}

@media (min-width: 1441px) {
  main {
    max-width: 960px !important;
    margin-right: 4rem;
  }
}

/* Large monitor adjustments - bring sidebar closer to content */
@media (min-width: 1600px) {
  body {
    grid-template-columns: minmax(var(--sidebar-width), auto) minmax(0, 960px) 1fr;
    grid-template-areas: 
      "sidebar main .";
    justify-content: center;
    gap: 3rem 2rem;
  }
  
  main {
    margin: 0;
  }
}

/* Table of contents styling */
.table-of-contents {
  font-size: 0.875rem;
}

.table-of-contents h2 {
  font-size: 1.125rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--muted-border-color);
}

.table-of-contents nav ul {
  list-style: none;
  padding-left: 0;
  margin: 0;
}

.table-of-contents nav ul ul {
  padding-left: 1.25rem;
  margin-top: 0.25rem;
}

.table-of-contents nav li {
  margin: 0.25rem 0;
}

.table-of-contents nav a {
  text-decoration: none;
  color: var(--color);
  display: block;
  padding: 0.25rem 0.5rem;
  border-radius: 0.25rem;
  transition: background-color 0.2s;
}

.table-of-contents nav a:hover {
  background-color: var(--secondary-focus);
}

.table-of-contents nav a.active {
  background-color: var(--primary-focus);
  color: var(--primary-inverse);
}

/* Responsive behavior */
@media (max-width: 768px) {
  body {
    grid-template-columns: 1fr;
    grid-template-areas: 
      "main";
    padding: 0;
    /* Reset max-width for mobile */
    max-width: none;
  }
  
  main {
    max-width: 100% !important;
    margin-right: 0;
    padding: 1rem;
    /* Ensure proper width on mobile */
    width: 100%;
    overflow-x: visible;
  }
  
  aside.sidebar {
    position: fixed;
    left: -100%;
    width: var(--sidebar-width);
    z-index: 1000;
    transition: left 0.3s ease;
    background: var(--card-background-color);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    height: 100vh;
    top: 0;
  }
  
  aside.sidebar.open {
    left: 0;
    box-shadow: 0 0 0 100vmax rgba(0, 0, 0, 0.7);
  }
  
  /* Overlay effect when sidebar is open */
  aside.sidebar.open::before {
    content: '';
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
    -webkit-backdrop-filter: blur(5px);
    z-index: -1;
  }
  
  /* Mobile menu toggle */
  .sidebar-toggle {
    display: block;
    position: fixed;
    top: 1rem;
    left: 1rem;
    z-index: 1001;
    background: var(--primary);
    color: var(--primary-inverse);
    border: none;
    padding: 0.5rem;
    border-radius: 0.25rem;
    cursor: pointer;
  }
}

@media (min-width: 769px) {
  .sidebar-toggle {
    display: none;
  }
}

/* Sidebar scrollbar styling */
aside.sidebar::-webkit-scrollbar {
  width: 6px;
}

aside.sidebar::-webkit-scrollbar-track {
  background: transparent;
}

aside.sidebar::-webkit-scrollbar-thumb {
  background: var(--muted-color);
  border-radius: 3px;
}

aside.sidebar::-webkit-scrollbar-thumb:hover {
  background: var(--color);
}

/* Make pre tags scrollable instead of expanding the page */
pre {
  overflow-x: auto;
  max-width: 100%;
}

/* Prevent horizontal scroll on mobile */
@media (max-width: 768px) {
  /* Don't use overflow-x: hidden on body to preserve pinch-to-zoom */
  html, body {
    overflow-x: auto;
  }
  
  pre, code {
    white-space: pre-wrap;
    word-wrap: break-word;
    word-break: break-word;
  }
  
  /* More specific selectors to prevent breaking zoom */
  main > *, 
  aside > * {
    max-width: 100%;
    box-sizing: border-box;
  }
  
  /* Make header nav use full width on mobile */
  header nav {
    width: 100%;
  }
  
  header nav ul {
    width: 100%;
    display: flex;
    justify-content: space-around;
  }
  
  header nav ul li {
    flex: 1;
    text-align: center;
  }
  
  header nav ul li a {
    display: block;
    width: 100%;
    padding: 0.75rem 0.5rem;
  }
}