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

:root {
  /* Core Colors */
  --background: #0A0A0A;
  --foreground: #FAFAFA;
  --muted: #1A1A1A;
  --muted-foreground: #737373;
  --accent: #4A69BD;
  --accent-foreground: #0A0A0A;
  --border: #262626;
  --border-hover: #404040;
  --input: #1A1A1A;
  --card: #0F0F0F;
  --card-foreground: #FAFAFA;
  --ring: #4A69BD;

  /* Status Colors */
  --success: #22C55E;
  --warning: #F59E0B;
  --error: #EF4444;

  /* Typography Scales */
  --font-sans: "Inter Tight", "Inter", system-ui, sans-serif;
  --font-display: "Playfair Display", Georgia, serif;
  --font-mono: "JetBrains Mono", "Fira Code", monospace;

  /* Typography Tracking */
  --tracking-tighter: -0.06em;
  --tracking-tight: -0.04em;
  --tracking-normal: -0.01em;
  --tracking-wide: 0.05em;
  --tracking-wider: 0.1em;
  --tracking-widest: 0.2em;

  /* Reader Preferences (Defaults) */
  --reader-font-size: 1.1rem;
  --reader-font-family: var(--font-sans);
  --sidebar-width: 320px;
  --toc-width: 250px;
}

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

body {
  background: var(--background);
  color: var(--foreground);
  font-family: var(--font-sans);
  letter-spacing: var(--tracking-normal);
  line-height: 1.6;
  overflow: hidden;
  height: 100vh;
  margin: 0;
}

/* MANDATORY TACTILE NOISE OVERLAY */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 9999;
  opacity: 0.015;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
}

/* MANDATORY BRUTALIST FOCUS STATES */
*:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* MANDATORY CUSTOM SCROLLBAR */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: var(--background); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 0; }
::-webkit-scrollbar-thumb:hover { background: var(--border-hover); }

/* SELECTION */
::selection { background: var(--accent); color: var(--accent-foreground); }

/* Utility Classes */
.text-display {
  font-family: var(--font-display);
  letter-spacing: var(--tracking-tighter);
  line-height: 1;
}

.text-headline {
  font-family: var(--font-sans);
  letter-spacing: var(--tracking-tight);
  font-weight: 700;
  line-height: 1.1;
}

.text-label {
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wider);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--muted-foreground);
}

/* Layout Screens */
.app-container {
  display: flex;
  height: 100vh;
  width: 100vw;
  overflow: hidden;
}

/* Sidebar */
aside.sidebar {
  width: var(--sidebar-width);
  background: var(--card);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  transition: transform 200ms ease-in-out;
  z-index: 10;
}

.sidebar-header {
  padding: 2rem 1.5rem;
  border-bottom: 1px solid var(--border);
}

.sidebar-content {
  flex: 1;
  overflow-y: auto;
  padding: 1.5rem 1rem;
}

/* Sidebar Search */
.search-container {
  position: relative;
  width: 100%;
}

.search-input {
  width: 100%;
  height: 2.5rem;
  background: var(--input);
  border: 1px solid var(--border);
  color: var(--foreground);
  padding: 0 1rem 0 2.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  transition: all 150ms;
}

.search-input:focus {
  outline: none;
  border-color: var(--accent);
}

.search-icon {
  position: absolute;
  left: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  width: 14px;
  height: 14px;
  color: var(--muted-foreground);
  pointer-events: none;
}

/* Sidebar Navigation */
.nav-section {
  margin-bottom: 2rem;
}

.nav-section-title {
  padding: 0 0.75rem;
  margin-bottom: 0.75rem;
}

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

.nav-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.65rem 0.75rem;
  text-decoration: none;
  color: var(--muted-foreground);
  font-size: 0.875rem;
  border-radius: 8px;
  transition: all 150ms;
  cursor: pointer;
  margin-bottom: 0.25rem;
}

.nav-item:hover {
  color: var(--foreground);
  background: var(--muted);
}

.nav-item.active {
  background: rgba(74, 105, 189, 0.1);
  color: var(--accent);
  font-weight: 500;
}

.nav-item.active::after {
  content: "";
  margin-left: auto;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

.nav-item i {
  font-size: 1.1rem;
}

/* Main Content */
main.viewer {
  flex: 1;
  display: flex;
  flex-direction: column;
  background: var(--background);
  position: relative;
  overflow: hidden;
}

.progress-bar {
  position: absolute;
  top: 0;
  left: 0;
  height: 2px;
  width: 0%;
  background: var(--accent);
  z-index: 100;
  transition: width 100ms;
}

.viewer-toolbar {
  height: 64px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  background: var(--card);
}

.viewer-content {
  flex: 1;
  overflow-y: auto;
  padding: 3rem;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.viewer-container {
  width: 100%;
  max-width: 900px;
  background: var(--card);
  border: 1px solid var(--border);
  padding: 4rem;
  position: relative;
}

.viewer-container::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  height: 4px;
  width: 64px;
  background: var(--accent);
}

/* Enhanced Markdown Reader Styles */
#markdown-render {
  color: var(--foreground);
  font-family: var(--reader-font-family);
  line-height: 1.8;
  font-size: var(--reader-font-size);
}

#markdown-render h1 { 
    margin-bottom: 2.5rem; 
    font-size: 3.5rem; 
    font-family: var(--font-display); 
    font-weight: 700; 
    letter-spacing: var(--tracking-tighter); 
    line-height: 1;
}

#markdown-render h2 { 
    margin: 3.5rem 0 1.5rem; 
    font-size: 1.75rem; 
    font-family: var(--font-headline);
    border-bottom: 1px solid var(--border); 
    padding-bottom: 0.75rem; 
}

#markdown-render h3 {
    margin: 2.5rem 0 1rem;
    font-size: 1.25rem;
    font-family: var(--font-headline);
    color: var(--accent);
}

#markdown-render p { 
    margin-bottom: 1.5rem; 
    color: rgba(250, 250, 250, 0.85);
}

#markdown-render code { 
    font-family: var(--font-mono); 
    background: var(--muted); 
    padding: 0.2rem 0.4rem; 
    font-size: 0.9em;
    color: var(--accent);
}

#markdown-render pre { 
    background: #0d0d17; 
    padding: 2rem; 
    border: 1px solid var(--border); 
    overflow-x: auto; 
    margin: 2rem 0; 
    position: relative;
    border-radius: 4px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
}

#markdown-render pre::before {
    content: "CODE_LAYER";
    position: absolute;
    top: 0;
    right: 0;
    font-family: var(--font-mono);
    font-size: 0.6rem;
    padding: 0.5rem 1rem;
    color: var(--accent);
    background: rgba(74, 105, 189, 0.1);
    border-left: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
    letter-spacing: 2px;
}

#markdown-render pre code { 
    background: none; 
    padding: 0; 
    color: var(--foreground);
}

#markdown-render ul, #markdown-render ol { 
    margin-left: 1.5rem; 
    margin-bottom: 1.5rem; 
    color: rgba(250, 250, 250, 0.85);
}

#markdown-render li {
    margin-bottom: 0.5rem;
}

#markdown-render blockquote {
    border-left: 4px solid var(--accent);
    padding: 0.5rem 0 0.5rem 1.5rem;
    margin: 2rem 0;
    font-style: italic;
    background: var(--muted);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  height: 3rem;
  padding: 0 1.5rem;
  background: var(--accent);
  color: var(--accent-foreground);
  border: none;
  font-family: var(--font-sans);
  font-weight: bold;
  text-transform: uppercase;
  letter-spacing: var(--tracking-wider);
  font-size: 0.875rem;
  cursor: pointer;
  transition: all 150ms;
}

.btn:hover { opacity: 0.9; }
.btn:active { transform: translateY(1px); }

.btn i { transition: transform 150ms; }
.btn:hover i { transform: translateX(4px); }

/* Empty & Loading States */
.empty-state {
  text-align: center;
  padding-top: 20vh;
}

.empty-state h1 { margin-bottom: 1rem; color: var(--muted-foreground); }

/* PDF Viewer */
.pdf-viewer {
  width: 100%;
  height: 80vh;
  border: none;
}

/* Atmospheric effects */
.bg-glow {
  position: fixed;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
  z-index: -1;
}

.glow-1 {
  position: absolute;
  top: -25%;
  right: -25%;
  width: 50%;
  height: 50%;
  background: var(--accent);
  opacity: 0.02;
  filter: blur(120px);
}

.glow-2 {
  position: absolute;
  bottom: -25%;
  left: -25%;
  width: 50%;
  height: 50%;
  background: var(--accent);
  opacity: 0.02;
  filter: blur(120px);
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.animate-fade-in {
  animation: fadeIn 300ms ease-out forwards;
}

/* Settings Overlay */
.settings-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(8px);
  z-index: 2000;
  display: none;
  align-items: center;
  justify-content: center;
}

.settings-overlay.open {
  display: flex;
}

.settings-panel {
  width: 100%;
  max-width: 400px;
  background: var(--card);
  border: 1px solid var(--border);
  padding: 2rem;
  position: relative;
}

.settings-panel::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  height: 4px;
  width: 64px;
  background: var(--accent);
}

.settings-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
}

.settings-group {
  margin-bottom: 2rem;
}

.settings-slider {
  width: 100%;
  height: 4px;
  background: var(--border);
  appearance: none;
  outline: none;
  margin: 1rem 0;
}

.settings-slider::-webkit-slider-thumb {
  appearance: none;
  width: 16px;
  height: 16px;
  background: var(--accent);
  cursor: pointer;
}

.toggle-group {
  display: flex;
  gap: 1px;
  background: var(--border);
  margin-top: 1rem;
}

.toggle-btn {
  flex: 1;
  height: 2.5rem;
  background: var(--muted);
  border: none;
  font-size: 0.7rem;
  color: var(--muted-foreground);
}

.toggle-btn.active {
  background: var(--accent);
  color: var(--accent-foreground);
}

/* TOC Sidebar */
.toc-sidebar {
  width: var(--toc-width);
  background: var(--background);
  border-left: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.toc-header {
  padding: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.toc-content {
  flex: 1;
  overflow-y: auto;
  padding: 1rem;
}

.toc-link {
  display: block;
  padding: 0.5rem 0.75rem;
  color: var(--muted-foreground);
  text-decoration: none;
  font-size: 0.8rem;
  border-left: 2px solid transparent;
  transition: all 150ms;
  margin-bottom: 0.25rem;
}

.toc-link:hover {
  color: var(--foreground);
  background: var(--muted);
}

.toc-link.active {
  color: var(--accent);
  border-left-color: var(--accent);
  background: rgba(74, 105, 189, 0.05);
}

/* Inline TOC Card */
.inline-toc {
  background: var(--muted);
  border: 1px solid var(--border);
  padding: 1.5rem;
  margin-bottom: 3rem;
  border-left: 4px solid var(--accent);
}

.inline-toc h4 {
  margin-bottom: 1rem;
  color: var(--accent);
}

.inline-toc ul {
  list-style: none !important;
  margin-left: 0 !important;
}

.inline-toc li {
  margin-bottom: 0.5rem;
}

.inline-toc a {
  color: var(--foreground);
  text-decoration: none;
  font-size: 0.95rem;
  opacity: 0.7;
  transition: opacity 150ms;
}

.inline-toc a:hover {
  opacity: 1;
  text-decoration: underline;
}

/* Responsive */
@media (max-width: 1024px) {
  .toc-sidebar {
    display: none !important;
  }
}

@media (max-width: 768px) {
  #menu-toggle {
    display: flex !important;
  }

  aside.sidebar {
    position: fixed;
    height: 100vh;
    transform: translateX(-100%);
    box-shadow: 20px 0 50px rgba(0, 0, 0, 0.5);
    z-index: 1000;
  }

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

  .viewer-toolbar {
    padding: 0 1rem;
  }

  .viewer-content {
    padding: 1.5rem 1rem;
  }

  .viewer-container {
    padding: 2.5rem 1.5rem;
    border: none;
  }

  /* Reduce typography for mobile */
  #markdown-render h1 { 
    font-size: 2.5rem; 
    margin-bottom: 2rem;
  }

  #markdown-render h2 { 
    font-size: 1.4rem; 
    margin: 2.5rem 0 1rem;
  }

  #markdown-render p, #markdown-render li {
    line-height: 1.6;
  }

  #markdown-render pre {
    padding: 1.25rem;
    margin: 1.5rem -1.5rem; /* Full width touch area */
    border-radius: 0;
    font-size: 0.85rem;
  }

  .text-display {
    font-size: 2rem !important;
  }

  .btn {
    padding: 0 1rem;
    font-size: 0.75rem;
  }

  /* Make sure settings icon isn't squished */
  #current-filename {
    font-size: 0.8rem !important;
    max-width: 120px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  #reading-time {
    display: none;
  }
}

/* Mermaid Diagrams */
.mermaid {
    background: transparent !important;
    display: flex;
    justify-content: center;
    margin: 2rem 0;
    width: 100% !important;
}

.mermaid svg {
    max-width: 100% !important;
    height: auto !important;
    background: rgba(255, 255, 255, 0.03) !important;
    border-radius: 8px;
    padding: 1rem;
}

/* Ensure Mermaid text is visible on dark backgrounds */
.mermaid .node rect, .mermaid .node circle, .mermaid .node ellipse, .mermaid .node polygon, .mermaid .node path {
    stroke: var(--accent) !important;
}

.mermaid .node .label {
    color: var(--foreground) !important;
}