/* ============================================================
   MinimalOS NextGen — Documentation Stylesheet
   Pure static HTML docs, no Jekyll required.
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

/* ── Reset & Base ─────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg-primary:      #0d1117;
  --bg-secondary:    #161b22;
  --bg-tertiary:     #1c2128;
  --bg-nav-active:   #1f2937;
  --bg-code:         #1c2128;
  --bg-code-inline:  #272e38;
  --bg-table-head:   #1c2128;
  --bg-table-alt:    #131920;
  --bg-callout-note: #0d2240;
  --bg-callout-warn: #3b2e00;
  --bg-callout-todo: #1a1a2e;
  --bg-callout-imp:  #0a2e1a;

  --border-primary:  #30363d;
  --border-subtle:   #21262d;
  --border-accent:   #1f6feb;
  --border-callout-note: #1f6feb;
  --border-callout-warn: #d29922;
  --border-callout-todo: #6e7681;
  --border-callout-imp:  #238636;

  --text-primary:    #e6edf3;
  --text-secondary:  #8b949e;
  --text-muted:      #6e7681;
  --text-link:       #58a6ff;
  --text-link-hover: #79c0ff;
  --text-heading:    #f0f6fc;

  --accent-blue:     #58a6ff;
  --accent-green:    #3fb950;
  --accent-yellow:   #d29922;
  --accent-red:      #f85149;
  --accent-purple:   #bc8cff;

  /* Syntax Highlighting */
  --syn-keyword:     #ff7b72;
  --syn-string:      #a5d6ff;
  --syn-comment:     #8b949e;
  --syn-function:    #d2a8ff;
  --syn-number:      #79c0ff;
  --syn-type:        #ffa657;
  --syn-constant:    #79c0ff;

  --sidebar-width:   280px;
  --header-height:   60px;
  --content-max:     900px;
  --radius:          8px;
  --transition:      0.2s ease;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 1rem);
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: var(--text-link);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--text-link-hover);
  text-decoration: underline;
}

img { max-width: 100%; }

/* ── Site Header ──────────────────────────────────────────── */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-primary);
  display: flex;
  align-items: center;
  padding: 0 1.5rem;
  z-index: 1000;
  backdrop-filter: blur(12px);
  background: rgba(22, 27, 34, 0.85);
}

.site-header .logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text-heading);
  text-decoration: none;
  white-space: nowrap;
}

.site-header .logo:hover {
  color: var(--accent-blue);
  text-decoration: none;
}

.site-header .logo-icon {
  width: 28px;
  height: 28px;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  color: #fff;
  font-weight: 700;
}

.header-right {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.header-right a {
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius);
  transition: all var(--transition);
}

.header-right a:hover {
  color: var(--text-primary);
  background: var(--bg-tertiary);
  text-decoration: none;
}

/* ── Mobile Menu Toggle ───────────────────────────────────── */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 0.5rem;
  margin-right: 0.5rem;
  border-radius: var(--radius);
  transition: all var(--transition);
}

.menu-toggle:hover {
  color: var(--text-primary);
  background: var(--bg-tertiary);
}

.menu-toggle svg {
  width: 22px;
  height: 22px;
  display: block;
}

/* ── Sidebar ──────────────────────────────────────────────── */
.sidebar {
  position: fixed;
  top: var(--header-height);
  left: 0;
  bottom: 0;
  width: var(--sidebar-width);
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-primary);
  overflow-y: auto;
  padding: 1.25rem 0;
  z-index: 900;
  transition: transform 0.3s ease;
}

.sidebar::-webkit-scrollbar {
  width: 4px;
}

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

.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  z-index: 899;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.sidebar-overlay.visible {
  opacity: 1;
}

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

.sidebar nav > ul > li {
  margin-bottom: 0.1rem;
}

.sidebar nav a {
  display: block;
  padding: 0.5rem 1.5rem;
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 450;
  border-left: 3px solid transparent;
  transition: all var(--transition);
}

.sidebar nav a:hover {
  color: var(--text-primary);
  background: var(--bg-nav-active);
  text-decoration: none;
}

.sidebar nav a.active {
  color: var(--accent-blue);
  background: var(--bg-nav-active);
  border-left-color: var(--accent-blue);
  font-weight: 600;
}

/* Subsystem children — indented */
.sidebar nav ul ul {
  margin-left: 0;
}

.sidebar nav ul ul a {
  padding-left: 2.5rem;
  font-size: 0.825rem;
}

.sidebar .nav-section-title {
  display: block;
  padding: 0.5rem 1.5rem 0.25rem;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  cursor: default;
  margin-top: 0.75rem;
}

/* ── Main Content ─────────────────────────────────────────── */
.main-content {
  margin-left: var(--sidebar-width);
  margin-top: var(--header-height);
  min-height: calc(100vh - var(--header-height));
  padding: 2.5rem 3rem 4rem;
}

.content-wrapper {
  max-width: var(--content-max);
  margin: 0 auto;
}

/* ── Typography ───────────────────────────────────────────── */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-heading);
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: 0.75rem;
}

h1 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  background: linear-gradient(135deg, var(--text-heading), var(--accent-blue));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

h2 {
  font-size: 1.45rem;
  margin-top: 2.5rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border-subtle);
}

h3 {
  font-size: 1.15rem;
  margin-top: 1.75rem;
}

h4 {
  font-size: 1rem;
  margin-top: 1.25rem;
  color: var(--text-secondary);
}

p {
  margin-bottom: 1rem;
}

.subtitle {
  font-size: 1.15rem;
  font-weight: 300;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.hero-buttons {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1.5rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--accent-blue);
  color: #fff;
}

.btn-primary:hover {
  background: #4393e6;
  color: #fff;
  text-decoration: none;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(88, 166, 255, 0.3);
}

.btn-outline {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border-primary);
}

.btn-outline:hover {
  color: var(--text-primary);
  border-color: var(--text-secondary);
  text-decoration: none;
  transform: translateY(-1px);
}

hr {
  border: none;
  border-top: 1px solid var(--border-subtle);
  margin: 2rem 0;
}

strong { font-weight: 600; }

ul, ol {
  margin-bottom: 1rem;
  padding-left: 1.75rem;
}

li {
  margin-bottom: 0.35rem;
}

li > ul, li > ol {
  margin-top: 0.35rem;
  margin-bottom: 0.35rem;
}

/* Checklists */
ul.checklist {
  list-style: none;
  padding-left: 0;
}

ul.checklist li {
  position: relative;
  padding-left: 1.75rem;
}

ul.checklist li::before {
  position: absolute;
  left: 0;
  font-size: 0.9rem;
}

ul.checklist li.done::before       { content: '✅'; }
ul.checklist li.pending::before    { content: '🔲'; }
ul.checklist li.inprogress::before { content: '🔧'; }

/* ── Code Blocks ──────────────────────────────────────────── */
code {
  font-family: 'JetBrains Mono', 'Cascadia Code', 'Fira Code', monospace;
  font-size: 0.85em;
}

:not(pre) > code {
  background: var(--bg-code-inline);
  padding: 0.15em 0.4em;
  border-radius: 4px;
  color: var(--accent-blue);
  font-size: 0.85em;
}

pre {
  background: var(--bg-code);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  overflow-x: auto;
  margin-bottom: 1.25rem;
  line-height: 1.55;
  position: relative;
}

pre code {
  background: none;
  padding: 0;
  border-radius: 0;
  color: var(--text-primary);
  font-size: 0.85rem;
}

pre .lang-label {
  position: absolute;
  top: 0.5rem;
  right: 0.75rem;
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  font-family: 'Inter', sans-serif;
  font-weight: 600;
  user-select: none;
}

/* Minimal syntax highlighting via classes */
.kw { color: var(--syn-keyword); }     /* keyword */
.str { color: var(--syn-string); }     /* string */
.cmt { color: var(--syn-comment); font-style: italic; }  /* comment */
.fn { color: var(--syn-function); }    /* function */
.num { color: var(--syn-number); }     /* number */
.ty { color: var(--syn-type); }        /* type */
.cn { color: var(--syn-constant); }    /* constant */

/* ── Tables ───────────────────────────────────────────────── */
table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.25rem;
  font-size: 0.9rem;
}

th, td {
  padding: 0.65rem 1rem;
  text-align: left;
  border: 1px solid var(--border-primary);
}

th {
  background: var(--bg-table-head);
  font-weight: 600;
  color: var(--text-heading);
  font-size: 0.85rem;
  white-space: nowrap;
}

tr:nth-child(even) {
  background: var(--bg-table-alt);
}

tr:hover {
  background: var(--bg-nav-active);
}

/* ── Callouts / Admonitions ───────────────────────────────── */
.callout {
  border-left: 4px solid;
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1rem 1.25rem;
  margin-bottom: 1.25rem;
  font-size: 0.9rem;
}

.callout-title {
  font-weight: 700;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 0.35rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.callout.note {
  background: var(--bg-callout-note);
  border-color: var(--border-callout-note);
}

.callout.note .callout-title { color: var(--accent-blue); }

.callout.warning {
  background: var(--bg-callout-warn);
  border-color: var(--border-callout-warn);
}

.callout.warning .callout-title { color: var(--accent-yellow); }

.callout.todo {
  background: var(--bg-callout-todo);
  border-color: var(--border-callout-todo);
}

.callout.todo .callout-title { color: var(--text-muted); }

.callout.important {
  background: var(--bg-callout-imp);
  border-color: var(--border-callout-imp);
}

.callout.important .callout-title { color: var(--accent-green); }

/* ── Status Labels ────────────────────────────────────────── */
.label {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.2rem 0.65rem;
  border-radius: 100px;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.label-green {
  background: rgba(63, 185, 80, 0.15);
  color: var(--accent-green);
  border: 1px solid rgba(63, 185, 80, 0.3);
}

.label-yellow {
  background: rgba(210, 153, 34, 0.15);
  color: var(--accent-yellow);
  border: 1px solid rgba(210, 153, 34, 0.3);
}

.label-red {
  background: rgba(248, 81, 73, 0.15);
  color: var(--accent-red);
  border: 1px solid rgba(248, 81, 73, 0.3);
}

/* ── TOC (Table of Contents) ──────────────────────────────── */
.toc {
  background: var(--bg-secondary);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  margin-bottom: 2rem;
}

.toc summary {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text-heading);
  cursor: pointer;
  user-select: none;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.toc summary::before {
  content: '▸';
  transition: transform var(--transition);
  font-size: 0.75rem;
}

.toc[open] summary::before {
  transform: rotate(90deg);
}

.toc ul {
  margin-top: 0.75rem;
  margin-bottom: 0;
  padding-left: 1.25rem;
}

.toc li {
  margin-bottom: 0.3rem;
}

.toc a {
  color: var(--text-secondary);
  font-size: 0.85rem;
}

.toc a:hover {
  color: var(--text-link);
}

/* ── ASCII Diagrams ───────────────────────────────────────── */
pre.diagram {
  font-size: 0.78rem;
  line-height: 1.4;
  border-color: var(--border-subtle);
  background: var(--bg-primary);
  color: var(--text-secondary);
}

/* ── Mermaid Diagrams ────────────────────────────────────── */
pre.mermaid {
  background: transparent;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  text-align: center;
  padding: 1.5rem 1rem;
  margin-bottom: 1.25rem;
}

pre.mermaid svg {
  max-width: 100%;
  height: auto;
}

/* ── Footer ───────────────────────────────────────────────── */
.site-footer {
  margin-top: 4rem;
  padding: 1.5rem 0;
  border-top: 1px solid var(--border-subtle);
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 1024px) {
  .main-content {
    padding: 2rem 2rem 3rem;
  }
}

@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }

  .sidebar {
    transform: translateX(-100%);
    width: 280px;
    top: var(--header-height);
  }

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

  .sidebar-overlay.visible {
    display: block;
  }

  .main-content {
    margin-left: 0;
    padding: 1.5rem 1.25rem 3rem;
  }

  h1 { font-size: 1.6rem; }
  h2 { font-size: 1.25rem; }

  table {
    display: block;
    overflow-x: auto;
    white-space: nowrap;
  }

  .hero-buttons {
    flex-direction: column;
  }

  .btn {
    text-align: center;
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .main-content {
    padding: 1.25rem 1rem 2rem;
  }

  pre {
    padding: 0.75rem;
    font-size: 0.78rem;
  }

  .header-right a:not(:last-child) {
    display: none;
  }
}

/* ── Scroll back-to-top ───────────────────────────────────── */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-primary);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transition: all var(--transition);
  z-index: 800;
}

.back-to-top.visible {
  opacity: 1;
  pointer-events: auto;
}

.back-to-top:hover {
  background: var(--accent-blue);
  border-color: var(--accent-blue);
  color: #fff;
  transform: translateY(-2px);
}

/* ── Heading Anchors ──────────────────────────────────────── */
h2 .anchor, h3 .anchor, h4 .anchor {
  color: var(--text-muted);
  font-weight: 400;
  text-decoration: none;
  margin-left: 0.35rem;
  opacity: 0;
  transition: opacity var(--transition);
}

h2:hover .anchor, h3:hover .anchor, h4:hover .anchor {
  opacity: 1;
}

.anchor:hover {
  color: var(--accent-blue);
  text-decoration: none;
}

/* ── Animations ───────────────────────────────────────────── */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

.content-wrapper {
  animation: fadeIn 0.35s ease;
}