/* =============================================================================
   mdbind — Modern Reader & Documentation Stylesheet
   Designed for Krewire Book & Documentation Workload
   Harmonized with Krewire Pop-Art / Neo-Brutalist Design System
   ============================================================================= */

/* ── Light & Dark Theme Design Tokens ─────────────────────────────────────── */
:root {
  color-scheme: light;
  --base-1: #FAF8F4;
  --base-1-content: #0B1F3B;
  --base-2: #f2ede4;
  --base-2-content: #57677d;
  --base-3: #e8e2d5;
  --base-3-content: #334155;
  
  --primary: #39D353;
  --primary-content: #0B1F3B;
  --secondary: #00D1C1;
  --secondary-content: #0B1F3B;
  --accent: #FF3B2E;
  --accent-content: #ffffff;
  
  --ghost: #e8e3d8;
  --ghost-content: #57677d;
  --neutral: rgba(11, 31, 59, 0.15);
  --neutral-content: #57677d;
  
  --success: #39D353;
  --success-content: #0B1F3B;
  --info: #00D1C1;
  --info-content: #0B1F3B;
  --warning: #ffb703;
  --warning-content: #0B1F3B;
  --error: #FF3B2E;
  --error-content: #ffffff;
  
  --ink: #0B1F3B;
  --muted: #57677d;
  --paper: #FAF8F4;
  --border: #0B1F3B;
  --border-subtle: rgba(11, 31, 59, 0.15);

  --pop-border: 2px solid #0B1F3B;
  --pop-border-thin: 1.5px solid #0B1F3B;
  --pop-shadow-sm: 2px 2px 0px #0B1F3B;
  --pop-shadow: 4px 4px 0px #0B1F3B;
  --pop-shadow-lg: 6px 6px 0px #0B1F3B;

  --code-bg: #0B1F3B;
  --code-fg: #FAF8F4;
  --code-bar: #071426;

  --show-sun: inline;
  --show-moon: none;
}

:root[data-theme="dark"], html[data-theme="dark"] {
  color-scheme: dark;
  --base-1: #0B1F3B;
  --base-1-content: #FAF8F4;
  --base-2: #112646;
  --base-2-content: #9ab0ce;
  --base-3: #18335a;
  --base-3-content: #cbd5e1;
  
  --primary: #39D353 !important;
  --primary-content: #0B1F3B !important;
  --secondary: #00D1C1 !important;
  --secondary-content: #0B1F3B !important;
  --accent: #FF3B2E;
  --accent-content: #ffffff;
  
  --ghost: #162f52;
  --ghost-content: #9ab0ce;
  --neutral: rgba(250, 248, 244, 0.18);
  --neutral-content: #9ab0ce;
  
  --success: #39D353;
  --success-content: #0B1F3B;
  --info: #00D1C1;
  --info-content: #0B1F3B;
  --warning: #ffb703;
  --warning-content: #0B1F3B;
  --error: #FF3B2E;
  --error-content: #ffffff;
  
  --ink: #FAF8F4;
  --muted: #9ab0ce;
  --paper: #0B1F3B;
  --border: #FAF8F4;
  --border-subtle: rgba(250, 248, 244, 0.18);

  --pop-border: 2px solid #FAF8F4;
  --pop-border-thin: 1.5px solid #FAF8F4;
  --pop-shadow-sm: 2px 2px 0px #39D353;
  --pop-shadow: 4px 4px 0px #39D353;
  --pop-shadow-lg: 6px 6px 0px #39D353;

  --code-bg: #071426;
  --code-fg: #FAF8F4;
  --code-bar: #040d1a;

  --show-sun: none;
  --show-moon: inline;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    color-scheme: dark;
    --base-1: #0B1F3B;
    --base-1-content: #FAF8F4;
    --base-2: #112646;
    --base-2-content: #9ab0ce;
    --base-3: #18335a;
    --base-3-content: #cbd5e1;
    --primary: #39D353 !important;
    --primary-content: #0B1F3B !important;
    --secondary: #00D1C1 !important;
    --secondary-content: #0B1F3B !important;
    --accent: #FF3B2E;
    --accent-content: #ffffff;
    --ghost: #162f52;
    --ghost-content: #9ab0ce;
    --neutral: rgba(250, 248, 244, 0.18);
    --neutral-content: #9ab0ce;
    --ink: #FAF8F4;
    --muted: #9ab0ce;
    --paper: #0B1F3B;
    --border: #FAF8F4;
    --border-subtle: rgba(250, 248, 244, 0.18);
    --pop-border: 2px solid #FAF8F4;
    --pop-border-thin: 1.5px solid #FAF8F4;
    --pop-shadow-sm: 2px 2px 0px #39D353;
    --pop-shadow: 4px 4px 0px #39D353;
    --pop-shadow-lg: 6px 6px 0px #39D353;
    --code-bg: #071426;
    --code-fg: #FAF8F4;
    --code-bar: #040d1a;
    --show-sun: none;
    --show-moon: inline;
  }
}

/* ── Base Reset & Typography ──────────────────────────────────────────────── */
* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
}

body {
  margin: 0;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Inter", Roboto, Helvetica, Arial, sans-serif;
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink);
  background-color: var(--paper);
  background-image: radial-gradient(var(--neutral) 1px, transparent 1px);
  background-size: 20px 20px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ── Topbar (Navbar) ──────────────────────────────────────────────────────── */
.topbar {
  background: var(--paper);
  border-bottom: var(--pop-border);
  position: sticky;
  top: 0;
  z-index: 40;
  backdrop-filter: blur(10px);
}

.topbar nav {
  max-width: 82rem;
  margin: 0 auto;
  padding: 0.75rem 1.25rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.topbar .brand {
  font-weight: 900;
  color: var(--ink);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-shrink: 0;
  font-size: 15px;
  letter-spacing: -0.02em;
}

.topbar .brand:hover {
  color: var(--ink);
}

.topbar .brand-mark {
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: var(--primary);
  color: var(--primary-content);
  border: var(--pop-border-thin);
  box-shadow: var(--pop-shadow-sm);
  font-size: 15px;
  font-weight: 900;
  line-height: 1;
}

.topbar .brand-text {
  font-weight: 900;
  font-size: 15px;
}

.topbar .brand .badge {
  font-family: ui-monospace, monospace;
  font-size: 11px;
  font-weight: 900;
  padding: 2px 7px;
  border-radius: 6px;
  background: var(--secondary);
  color: var(--secondary-content);
  border: var(--pop-border-thin);
  box-shadow: 1.5px 1.5px 0px var(--border);
  margin-left: 2px;
}

.topbar nav a.nav-link {
  color: var(--muted);
  text-decoration: none;
  font-size: 13.5px;
  font-weight: 700;
  padding: 5px 10px;
  border-radius: 6px;
  transition: all 0.15s ease;
}

.topbar nav a.nav-link:hover {
  background: var(--base-2);
  color: var(--primary);
}

.topbar .nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  margin-left: 0.5rem;
}

.topbar-actions {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.topbar nav a.nav-link.nav-link-github {
  background: var(--primary);
  color: var(--primary-content);
  border: var(--pop-border-thin);
  box-shadow: var(--pop-shadow-sm);
  padding: 4px 11px;
  border-radius: 6px;
  font-weight: 800;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.topbar nav a.nav-link.nav-link-github:hover {
  background: var(--primary);
  color: var(--primary-content);
  transform: translate(-1px, -1px);
}

.topbar .lang-switch {
  border: var(--pop-border-thin);
  box-shadow: var(--pop-shadow-sm);
  border-radius: 8px;
  background: var(--base-2);
  color: var(--ink);
  padding: 0.35rem 0.65rem;
  line-height: 1;
  font-size: 0.75rem;
  font-weight: 800;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  text-decoration: none;
  transition: all 0.15s ease;
}

.topbar .lang-switch:hover {
  background: var(--base-3);
  transform: translate(-1px, -1px);
}

/* Sidebar Hamburger Toggle */
.sidebar-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: var(--pop-border-thin);
  box-shadow: var(--pop-shadow-sm);
  border-radius: 8px;
  background: var(--base-2);
  color: var(--ink);
  cursor: pointer;
  transition: all 0.15s ease;
}

.sidebar-toggle:hover {
  background: var(--primary);
  color: var(--primary-content);
  transform: translate(-1px, -1px);
}

/* Theme Toggle Button */
.theme-toggle {
  width: 36px;
  height: 36px;
  border: var(--pop-border-thin);
  box-shadow: var(--pop-shadow-sm);
  border-radius: 8px;
  background: var(--base-2);
  color: var(--ink);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.15s ease;
}

.theme-toggle:hover {
  transform: translate(-1px, -1px);
  box-shadow: 3px 3px 0px var(--border);
  background: var(--base-3);
}

.theme-toggle:active {
  transform: translate(1px, 1px);
  box-shadow: 1px 1px 0px var(--border);
}

.theme-toggle svg {
  width: 17px;
  height: 17px;
  display: block;
}

.theme-toggle .icon-sun { display: var(--show-sun); }
.theme-toggle .icon-moon { display: var(--show-moon); }

/* ── Main Layout Grid ─────────────────────────────────────────────────────── */
.layout {
  flex: 1;
  width: 100%;
  max-width: 82rem;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

/* ── Sidebar (Table of Contents) ──────────────────────────────────────────── */
.sidebar {
  font-size: 13.5px;
  background: var(--paper);
}

.sidebar-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: var(--pop-border-thin);
}

.sidebar-head-title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.sidebar-head-actions {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.sidebar .sidebar-title {
  margin: 0;
  font-size: 11px;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--primary-content);
  background: var(--primary);
  border: var(--pop-border-thin);
  box-shadow: var(--pop-shadow-sm);
  padding: 3px 9px;
  border-radius: 6px;
  display: inline-block;
}

.toc-action-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border: var(--pop-border-thin);
  background: var(--base-2);
  border-radius: 6px;
  cursor: pointer;
  color: var(--muted);
  box-shadow: 1px 1px 0px var(--border);
  transition: all 0.15s ease;
}

.toc-action-btn:hover {
  background: var(--primary);
  color: var(--primary-content);
  transform: translate(-1px, -1px);
}

.sidebar-close {
  display: none;
  border: var(--pop-border-thin);
  background: var(--base-2);
  border-radius: 6px;
  width: 28px;
  height: 28px;
  font-size: 16px;
  line-height: 1;
  cursor: pointer;
  color: var(--ink);
  font-weight: 900;
  box-shadow: 1px 1px 0px var(--border);
  transition: all 0.15s ease;
}

.sidebar-close:hover {
  background: var(--accent);
  color: var(--accent-content);
  transform: translate(-1px, -1px);
}

.sidebar-overlay {
  display: none;
}

/* Sidebar Search Filter */
.sidebar-search {
  position: relative;
  display: flex;
  align-items: center;
  margin-bottom: 0.85rem;
}

.sidebar-search .search-icon-box {
  position: absolute;
  left: 0.7rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  pointer-events: none;
  transition: color 0.15s ease, transform 0.15s ease;
}

.sidebar-search:focus-within .search-icon-box {
  color: var(--primary);
  transform: scale(1.08);
}

.toc-search-input {
  width: 100%;
  font-family: inherit;
  font-size: 12.5px;
  font-weight: 600;
  padding: 0.5rem 2.2rem 0.5rem 2.2rem;
  border-radius: 9px;
  border: var(--pop-border);
  background: var(--base-2);
  color: var(--ink);
  box-shadow: var(--pop-shadow-sm);
  transition: all 0.15s cubic-bezier(0.2, 0.8, 0.2, 1);
  outline: none;
  line-height: 1.4;
}

.toc-search-input::-webkit-search-cancel-button,
.toc-search-input::-webkit-search-decoration {
  -webkit-appearance: none;
  appearance: none;
}

.toc-search-input::placeholder {
  color: var(--muted);
  opacity: 0.75;
  font-weight: 500;
}

.toc-search-input:hover {
  border-color: var(--primary);
  box-shadow: 2px 2px 0px var(--border);
}

.toc-search-input:focus {
  background: var(--base-1);
  border-color: var(--primary);
  box-shadow: 3px 3px 0px var(--primary);
  transform: translate(-1px, -1px);
}

.toc-search-kbd {
  position: absolute;
  right: 0.55rem;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 11px;
  font-weight: 800;
  line-height: 1;
  padding: 2.5px 5.5px;
  border-radius: 5px;
  background: var(--base-3);
  color: var(--base-2-content);
  border: 1px solid var(--border-subtle);
  box-shadow: 1px 1px 0px var(--border-subtle);
  pointer-events: none;
  transition: opacity 0.15s ease, transform 0.15s ease;
}

.sidebar-search:focus-within .toc-search-kbd {
  opacity: 0.2;
}

.toc-search-clear {
  position: absolute;
  right: 0.45rem;
  width: 20px;
  height: 20px;
  border: 1.5px solid var(--border);
  background: var(--base-3);
  color: var(--ink);
  font-size: 13px;
  font-weight: 900;
  line-height: 1;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 5px;
  box-shadow: 1px 1px 0px var(--border);
  transition: all 0.15s ease;
  padding: 0;
}

.toc-search-clear:hover {
  background: var(--accent);
  color: var(--accent-content);
  border-color: var(--accent);
  transform: scale(1.06);
}

.toc-no-results {
  padding: 0.65rem 0.75rem;
  font-size: 12px;
  font-weight: 700;
  color: var(--muted);
  text-align: center;
  background: var(--base-2);
  border: var(--pop-border-thin);
  border-radius: 8px;
  margin-bottom: 0.85rem;
  box-shadow: var(--pop-shadow-sm);
}

/* TOC Items */
.toc {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.toc-link, .toc-sub {
  display: flex;
  align-items: center;
  padding: 0.45rem 0.65rem;
  border-radius: 8px;
  color: var(--muted);
  text-decoration: none;
  font-weight: 600;
  border: 1px solid transparent;
  transition: all 0.15s ease;
  position: relative;
  min-width: 0;
}

.toc-link:hover, .toc-sub:hover {
  background: var(--base-2);
  color: var(--ink);
  border-color: var(--neutral);
  transform: translateX(2px);
}

.toc-link.active, .toc-sub.active {
  background: var(--base-2);
  color: var(--ink);
  font-weight: 800;
  border-left: 3.5px solid var(--primary);
  border-color: var(--neutral) var(--neutral) var(--neutral) var(--primary);
  box-shadow: var(--pop-shadow-sm);
}

.toc-sub {
  padding: 0.38rem 0.6rem 0.38rem 0.75rem;
  font-size: 13px;
  border-radius: 6px;
}

.toc-sub.active {
  color: var(--ink);
}

.toc .num {
  font-family: ui-monospace, monospace;
  font-size: 11px;
  font-weight: 700;
  margin-right: 0.5rem;
  padding: 1px 5px;
  border-radius: 4px;
  background: var(--base-3);
  color: var(--ink);
  border: 1px solid var(--neutral);
  flex-shrink: 0;
}

.toc-link.active .num, .toc-sub.active .num {
  background: var(--primary);
  color: var(--primary-content);
  border-color: var(--border);
}

.toc-text {
  flex: 1;
  min-width: 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* TOC Collapsible Groups */
.toc-group {
  margin-bottom: 3px;
  border-radius: 8px;
  transition: background-color 0.15s ease;
}

.toc-parent-row {
  display: flex;
  align-items: center;
  gap: 4px;
  border-radius: 8px;
}

.toc-parent-row .toc-link {
  flex: 1;
}

.toc-toggle {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border: var(--pop-border-thin);
  border-radius: 6px;
  background: var(--base-2);
  color: var(--muted);
  cursor: pointer;
  box-shadow: 1px 1px 0px var(--border);
  transition: all 0.18s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.toc-toggle:hover {
  background: var(--primary);
  color: var(--primary-content);
  transform: translate(-1px, -1px);
}

.toc-group.open > .toc-parent-row .toc-toggle {
  background: var(--base-3);
  color: var(--ink);
}

.toc-group.open > .toc-parent-row .toc-toggle:hover {
  background: var(--primary);
  color: var(--primary-content);
}

.toc-toggle svg {
  transition: transform 0.22s cubic-bezier(0.4, 0, 0.2, 1);
}

.toc-group.open > .toc-parent-row .toc-toggle svg {
  transform: rotate(90deg);
}

/* Collapsible Dropdown Submenu with Smooth Transition */
.toc-subs {
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  gap: 3px;
  margin: 0 0 0 0.85rem;
  padding-left: 0.55rem;
  border-left: 2px solid var(--neutral);
  transition: max-height 0.25s cubic-bezier(0.4, 0, 0.2, 1),
              opacity 0.2s ease,
              margin 0.2s ease;
  pointer-events: none;
}

.toc-group.open > .toc-subs {
  max-height: 1200px;
  opacity: 1;
  margin: 4px 0 8px 0.85rem;
  pointer-events: auto;
}

.toc-group.has-active > .toc-subs,
.toc-group:has(.active) > .toc-subs {
  border-left-color: var(--primary);
}

/* ── Content & Reader ─────────────────────────────────────────────────────── */
.layout > main,
.layout main {
  min-width: 0;
  max-width: 52rem;
}

/* Breadcrumbs */
nav.crumbs {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin-bottom: 1.25rem;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--muted);
  background: var(--base-2);
  padding: 4px 10px;
  border-radius: 8px;
  border: var(--pop-border-thin);
  box-shadow: 1.5px 1.5px 0px var(--border);
}

nav.crumbs a {
  color: var(--muted);
  text-decoration: none;
  transition: color 0.15s ease;
}

nav.crumbs a:hover {
  color: var(--primary);
}

nav.crumbs .sep {
  opacity: 0.4;
}

nav.crumbs .current {
  color: var(--ink);
  font-weight: 800;
}

/* Chapter Article */
.chapter {
  line-height: 1.75;
}

.chapter h1 {
  font-size: clamp(28px, 5vw, 40px);
  font-weight: 900;
  letter-spacing: -0.035em;
  line-height: 1.15;
  margin: 0 0 1.25rem;
  color: var(--ink);
  padding-bottom: 0.75rem;
  border-bottom: var(--pop-border);
}

.chapter h2 {
  font-size: clamp(20px, 3.5vw, 26px);
  font-weight: 900;
  letter-spacing: -0.025em;
  margin: 2.5rem 0 1rem;
  color: var(--ink);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.chapter h3 {
  font-size: clamp(16px, 2.5vw, 20px);
  font-weight: 800;
  letter-spacing: -0.015em;
  margin: 2rem 0 0.75rem;
  color: var(--ink);
}

.chapter p {
  margin: 0 0 1.25rem;
  color: var(--ink);
}

.chapter a {
  color: var(--primary);
  text-decoration: underline;
  text-underline-offset: 3px;
  font-weight: 700;
  transition: opacity 0.15s ease;
}

.chapter a:hover {
  opacity: 0.8;
}

.chapter strong {
  font-weight: 800;
}

.chapter hr {
  border: 0;
  height: 2px;
  background: var(--neutral);
  margin: 2.5rem 0;
}

/* Lists */
.chapter ul, .chapter ol {
  margin: 0 0 1.5rem;
  padding-left: 1.5rem;
}

.chapter li {
  margin-bottom: 0.5rem;
}

.chapter li::marker {
  color: var(--primary);
  font-weight: 900;
}

/* Inline Code */
.chapter code {
  font-family: ui-monospace, "SF Mono", Menlo, Monaco, Consolas, monospace;
  font-size: 0.88em;
  font-weight: 700;
  background: var(--base-2);
  color: var(--ink);
  padding: 0.2em 0.45em;
  border-radius: 6px;
  border: 1px solid var(--neutral);
}

/* Pre Code Blocks (Terminal / Code Window) */
.chapter pre {
  position: relative;
  background: var(--code-bg);
  color: var(--code-fg);
  padding: 1.25rem 1.25rem;
  overflow-x: auto;
  border-radius: 12px;
  border: var(--pop-border);
  box-shadow: var(--pop-shadow);
  margin: 1.5rem 0 2rem;
  line-height: 1.6;
}

.chapter pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: 13.5px;
  font-weight: 600;
  color: inherit;
}

/* Floating Code Copy Button */
.code-copy-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  font-family: ui-monospace, monospace;
  font-size: 11px;
  font-weight: 800;
  padding: 4px 10px;
  border-radius: 6px;
  background: var(--code-bar);
  color: var(--muted);
  border: 1px solid rgba(255, 255, 255, 0.15);
  cursor: pointer;
  opacity: 0;
  transition: all 0.15s ease;
  z-index: 10;
}

.chapter pre:hover .code-copy-btn,
.code-copy-btn:focus-visible {
  opacity: 1;
}

.code-copy-btn:hover {
  background: var(--primary);
  color: var(--primary-content);
  border-color: var(--primary);
  transform: translate(-1px, -1px);
}

.code-copy-btn .copied {
  color: var(--primary);
  font-weight: 900;
}

/* Blockquotes / Callout Boxes */
.chapter blockquote {
  margin: 1.75rem 0;
  padding: 1.25rem 1.25rem;
  border: var(--pop-border);
  border-left: 5px solid var(--primary);
  border-radius: 10px;
  background: var(--base-2);
  box-shadow: var(--pop-shadow-sm);
  color: var(--ink);
}

.chapter blockquote p:last-child {
  margin-bottom: 0;
}

.chapter blockquote strong {
  color: var(--ink);
}

/* Tables */
.chapter table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  margin: 1.75rem 0;
  border-radius: 10px;
  border: var(--pop-border);
  box-shadow: var(--pop-shadow);
  overflow: hidden;
  background: var(--paper);
}

.chapter th {
  background: var(--base-2);
  color: var(--ink);
  font-weight: 900;
  text-align: left;
  padding: 0.75rem 1rem;
  font-size: 13px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  border-bottom: var(--pop-border-thin);
}

.chapter td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--neutral);
  font-size: 14px;
}

.chapter tr:last-child td {
  border-bottom: none;
}

.chapter tr:hover td {
  background: var(--base-2);
}

/* ── Chapter Pager (Previous / Next Action Cards) ──────────────────────────── */
nav.pager {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin-top: 3.5rem;
  padding-top: 2rem;
  border-top: var(--pop-border);
}

@media (min-width: 32rem) {
  nav.pager {
    grid-template-columns: repeat(2, 1fr);
  }
}

nav.pager a {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  padding: 1.15rem 1.25rem;
  border-radius: 12px;
  border: var(--pop-border);
  box-shadow: var(--pop-shadow);
  background: var(--base-2);
  text-decoration: none;
  color: var(--ink);
  transition: all 0.15s ease;
  font-weight: 800;
  font-size: 15px;
}

nav.pager a:hover {
  transform: translate(-2px, -2px);
  box-shadow: var(--pop-shadow-lg);
  background: var(--paper);
  border-color: var(--primary);
  color: var(--ink);
}

nav.pager a:active {
  transform: translate(2px, 2px);
  box-shadow: var(--pop-shadow-sm);
}

nav.pager a.prev {
  grid-column: 1;
}

nav.pager a.next {
  grid-column: 2;
  text-align: right;
  margin-left: auto;
  width: 100%;
}

nav.pager a::before {
  content: "Previous Chapter";
  font-size: 10px;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
}

nav.pager a.next::before {
  content: "Next Chapter";
}

/* ── Footer ───────────────────────────────────────────────────────────────── */
.site-footer {
  border-top: var(--pop-border);
  background: var(--base-2);
  color: var(--muted);
  font-size: 13px;
  font-weight: 600;
}

.site-footer .inner {
  max-width: 82rem;
  margin: 0 auto;
  padding: 1.5rem 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.site-footer a {
  color: var(--ink);
  font-weight: 800;
  text-decoration: none;
}

.site-footer a:hover {
  color: var(--primary);
  text-decoration: underline;
}

/* ── Responsive Breakpoints ───────────────────────────────────────────────── */
/* Mobile & Tablet Drawer (md and below: < 1024px / < 64rem) */
@media (max-width: 63.99rem) {
  .sidebar-toggle {
    display: inline-flex !important;
  }

  .topbar .nav-links {
    display: none !important;
  }

  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: min(84vw, 20rem);
    max-width: 20rem;
    padding: 1.25rem 1.25rem 2rem;
    overflow-y: auto;
    border-right: var(--pop-border);
    box-shadow: 6px 0px 0px rgba(11, 31, 59, 0.2);
    transform: translateX(-100%);
    transition: transform 0.2s cubic-bezier(0.2, 0.8, 0.2, 1);
    z-index: 50;
  }

  .sidebar-close {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .sidebar-overlay {
    position: fixed;
    inset: 0;
    background: rgba(11, 31, 59, 0.5);
    backdrop-filter: blur(4px);
    z-index: 45;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease;
  }

  html.sidebar-open .sidebar {
    transform: translateX(0);
  }

  html.sidebar-open .sidebar-overlay {
    display: block;
    opacity: 1;
    pointer-events: auto;
  }

  html.sidebar-open {
    overflow: hidden;
  }
}

/* Tablet refinement (48rem - 63.99rem / 768px - 1023px) */
@media (min-width: 48rem) and (max-width: 63.99rem) {
  .layout {
    padding: 2rem 1.5rem 3.5rem;
  }
}

/* Desktop & Large Screens (lg and up: >= 1024px / >= 64rem) */
@media (min-width: 64rem) {
  .layout {
    grid-template-columns: 18rem minmax(0, 1fr);
    gap: 3.5rem;
    padding: 2.5rem 1.5rem 4rem;
  }

  .sidebar {
    align-self: start;
    position: sticky;
    top: 5rem;
    max-height: calc(100vh - 6rem);
    overflow-y: auto;
    padding-right: 0.5rem;
  }

  .sidebar::-webkit-scrollbar {
    width: 4px;
  }
  .sidebar::-webkit-scrollbar-thumb {
    background: var(--neutral);
    border-radius: 4px;
  }

  .sidebar-toggle, .sidebar-close, .sidebar-overlay {
    display: none !important;
  }
}

/* ── Chapter Overview Grid & Cards ────────────────────────────────────────── */
.overview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
  margin: 1.5rem 0 2rem;
}

.chapter-card {
  position: relative;
  display: flex;
  flex-direction: column;
  border: var(--pop-border);
  border-radius: 12px;
  padding: 1.4rem;
  background: var(--base-2);
  box-shadow: var(--pop-shadow-sm);
  transition: transform 0.15s cubic-bezier(0.2, 0.8, 0.2, 1), box-shadow 0.15s ease, border-color 0.15s ease;
  text-decoration: none;
}

.chapter-card:hover {
  border-color: var(--primary);
  box-shadow: var(--pop-shadow);
  transform: translate(-2px, -2px);
}

.chapter-card-head {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  margin-bottom: 0.85rem;
}

.chapter-card-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--primary);
  color: var(--primary-content);
  font-weight: 900;
  font-size: 0.85rem;
  border-radius: 7px;
  border: 1.5px solid var(--border);
  box-shadow: 1.5px 1.5px 0px var(--border);
  flex-shrink: 0;
}

.chapter-card-title {
  margin: 0 !important;
  font-size: 1.15rem !important;
  font-weight: 800 !important;
  line-height: 1.3 !important;
}

.chapter-card-title a {
  color: var(--ink) !important;
  text-decoration: none !important;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: color 0.15s ease;
}

.chapter-card-title a:hover {
  color: var(--primary) !important;
}

.chapter-card-title .arrow {
  color: var(--primary);
  font-weight: 900;
  display: inline-block;
  transition: transform 0.15s ease;
}

.chapter-card:hover .chapter-card-title .arrow {
  transform: translateX(4px);
}

.chapter-card-desc {
  margin-bottom: 0.95rem !important;
  font-size: 0.88rem !important;
  color: var(--base-2-content) !important;
  line-height: 1.55 !important;
  flex-grow: 1;
}

.chapter-card-list {
  margin: 0 !important;
  padding-left: 1.15rem !important;
  font-size: 0.83rem !important;
  color: var(--muted) !important;
  line-height: 1.5 !important;
}

.chapter-card-list li {
  margin-bottom: 0.25rem !important;
}

:root { --show-sun: block; --show-moon: none; }
:root[data-theme="dark"] { --show-sun: none; --show-moon: block; }
@media (prefers-color-scheme: dark) { :root:not([data-theme]) { --show-sun: none; --show-moon: block; } }
.theme-toggle { border: 1px solid var(--neutral); border-radius: 999px; background: transparent; color: var(--ink); padding: .35rem .5rem; line-height: 0; cursor: pointer; transition: border-color .2s ease, color .2s ease; }
.theme-toggle:hover { border-color: var(--primary); color: var(--primary); }
.theme-toggle svg { width: 1.05rem; height: 1.05rem; display: block; }
.theme-toggle .icon-sun { display: var(--show-sun); }
.theme-toggle .icon-moon { display: var(--show-moon); }