/* =====================================================
   HORIZON PAPER DESIGN SYSTEM
   읽기 경험에 최적화된 프론티어 디자인 시스템
   ===================================================== */

/* Material Icons (SVG) */
:root.symbols-font-pending .material-icons,
:root.symbols-font-pending .material-symbols-outlined {
  visibility: hidden;
}

.material-icons,
.material-symbols-outlined {
  display: inline-block;
  width: 1em;
  height: 1em;
  line-height: 1;
  vertical-align: middle;
}

.material-icons[data-symbol-ready="1"],
.material-symbols-outlined[data-symbol-ready="1"] {
  background-color: currentColor;
  -webkit-mask-image: var(--app-icon-url);
  mask-image: var(--app-icon-url);
  -webkit-mask-repeat: no-repeat;
  mask-repeat: no-repeat;
  -webkit-mask-position: center;
  mask-position: center;
  -webkit-mask-size: contain;
  mask-size: contain;
  text-indent: -9999px;
  overflow: hidden;
  white-space: nowrap;
}

/* =====================================================
   CSS VARIABLES - THEME SYSTEM
   ===================================================== */

:root,
:root[data-theme="light"] {
  /* === LIGHT THEME (Default) - PlayCity Brand === */
  --color-primary: var(--color-primary-dark);
  --color-primary-dark: #0057c3;
  --color-primary-light: #339cff;
  
  --color-secondary: #e04b4b;
  --color-secondary-dark: #c73333;
  --color-secondary-light: #f06868;
  
  --color-accent: #0857c3;
  --color-accent-dark: #064494;
  --color-accent-light: #2b78e4;
  
  --color-success: #4caf50;
  --color-warning: #ff9800;
  --color-danger: var(--color-secondary-dark);
  --color-info: #2196f3;
  
  /* Background Colors - Clean Modern */
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-tertiary: #f0f2f5;
  --bg-paper: #ffffff;
  --bg-elevated: #ffffff;
  
  /* Text Colors */
  --text-primary: #333333;
  --text-secondary: #5a5551;
  --text-muted: #7a756e;
  --text-disabled: #a8a19a;
  --text-inverse: #fdfcf8;
  
  /* Border Colors - Subtle */
  --border-light: #e9ecef;
  --border-default: #dee2e6;
  --border-dark: #ced4da;
  
  /* Interactive States - PlayCity Blue */
  --hover-overlay: rgba(0, 116, 255, 0.04);
  --focus-ring: rgba(0, 116, 255, 0.15);
  --selection-bg: rgba(0, 116, 255, 0.1);
  
  /* Shadows - Minimal/None (override Horizon v2) */
  --shadow-xs: none;
  --shadow-sm: none;
  --shadow-md: none;
  --shadow-lg: none;
  --shadow-xl: none;
  
  /* Typography Scale */
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  --font-size-4xl: 2.5rem;
  --font-size-5xl: 3rem;
  
  /* Line Heights */
  --line-height-tight: 1.3;
  --line-height-snug: 1.4;
  --line-height-normal: 1.6;
  --line-height-relaxed: 1.75;
  --line-height-loose: 1.9;

  /* Font Stacks */
  --font-sans: 'Noto Sans KR', 'Pretendard Variable', Pretendard, 'Noto Sans CJK KR', -apple-system, BlinkMacSystemFont, 'Apple SD Gothic Neo', 'Segoe UI', 'Malgun Gothic', Roboto, sans-serif;
  --font-serif: 'Noto Serif KR', 'Noto Sans KR', 'Pretendard Variable', Pretendard, 'Noto Sans CJK KR', 'Apple SD Gothic Neo', 'Malgun Gothic', serif;
  --font-mono: 'JetBrains Mono', 'D2Coding', 'Noto Sans KR', 'Noto Sans CJK KR', 'Apple SD Gothic Neo', 'Malgun Gothic', Consolas, Monaco, monospace;
  
  /* Spacing Scale */
  --spacing-0: 0;
  --spacing-1: 0.25rem;
  --spacing-2: 0.5rem;
  --spacing-3: 0.75rem;
  --spacing-4: 1rem;
  --spacing-5: 1.25rem;
  --spacing-6: 1.5rem;
  --spacing-8: 2rem;
  --spacing-10: 2.5rem;
  --spacing-12: 3rem;
  --spacing-16: 4rem;
  --spacing-20: 5rem;
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.25rem;
  --radius-lg: 0.25rem;
  --radius-xl: 0.25rem;
  --radius-2xl: 0.25rem;
  --radius-full: 9999px;
  
  /* Animation */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;
  
  /* Container Widths */
  --container-sm: 640px;
  --container-md: 768px;
  --container-lg: 1024px;
  --container-xl: 1280px;

  /* Layout Modes (Horizon v2 compatible) */
  --page-max: var(--container-xl); /* docs default */
  --paper-header-max: calc(var(--container-xl) - var(--spacing-16));
  --paper-header-pad-y: var(--spacing-2);
  --paper-header-gap: var(--spacing-3);
  
  /* Reading Optimized Values */
  --reading-max-width: 65ch;
  --paragraph-spacing: 1.5em;
  --article-font-size: var(--font-size-base);
  --article-line-height: var(--line-height-relaxed);

  /* Horizon v2 Token Aliases (Core) */
  --background: var(--bg-primary);
  --background-subtle: var(--bg-secondary);
  --foreground: var(--text-primary);

  --card: var(--bg-paper);
  --card-foreground: var(--text-primary);
  --surface: var(--bg-tertiary);
  --surface-foreground: var(--text-primary);

  --muted: var(--bg-secondary);
  --muted-foreground: var(--text-secondary);

  --border: var(--border-default);
  --border-strong: var(--border-dark);
  --input: var(--border-default);

  --primary: var(--color-primary);
  --primary-hover: var(--color-primary-dark);
  --primary-foreground: var(--text-inverse);

  --destructive: var(--color-danger);
  --success: var(--color-success);
  --warning: var(--color-warning);

  /* Horizon v2 spacing aliases (4px grid) */
  --space-0: 0px;
  --space-0-5: 2px;
  --space-1: 4px;
  --space-1-5: 6px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;
  --space-20: 80px;

  /* Horizon v2 shared tokens used by imported docs */
  --font-family: var(--font-sans);
  --font-family-serif: var(--font-serif);
  --radius: var(--radius-sm);
  --ring: var(--color-primary);
  --glow-primary: var(--focus-ring);
  --glow-success: rgba(76, 175, 80, 0.2);
  --glow-destructive: rgba(224, 75, 75, 0.2);

  --glass-bg: rgba(255, 255, 255, 0.86);
  --glass-border: rgba(0, 0, 0, 0.12);
  --logo-filter: invert(0);

  /* Overlay z-index tokens */
  --z-header: 50;
  --z-toast: 180;
  --z-overlay: 200;
  --z-popover: 220;
  --z-tooltip: 230;
}

:root[data-layout="docs"] {
  --page-max: var(--container-xl);
}

:root[data-layout="centered"] {
  --page-max: var(--container-lg);
}

:root[data-layout="content"] {
  --page-max: 100%;
}

/* === DARK THEME === */
:root[data-theme="dark"],
body.theme-dark {
  color-scheme: dark;
  --color-primary: #5a9fd4;
  --color-primary-dark: #4080b8;
  --color-primary-light: #7ab8e5;
  
  --color-secondary: #e57373;
  --color-secondary-dark: #d45858;
  --color-secondary-light: #ef8888;
  
  --color-accent: #4080b8;
  --color-accent-dark: #306399;
  --color-accent-light: #5a9fd4;
  
  --color-success: #7cb342;
  --color-warning: #ffb74d;
  --color-danger: #e57373;
  --color-info: #4fc3f7;
  
  --bg-primary: #1a1918;
  --bg-secondary: #232120;
  --bg-tertiary: #2d2a28;
  --bg-paper: #1e1d1c;
  --bg-elevated: #262422;
  
  --text-primary: #e8e6e3;
  --text-secondary: #b8b5b0;
  --text-muted: #8a8680;
  --text-disabled: #5a5650;
  --text-inverse: #1a1918;
  
  --border-light: #353230;
  --border-default: #403c39;
  --border-dark: #4a4542;
  
  --hover-overlay: rgba(90, 159, 212, 0.08);
  --focus-ring: rgba(90, 159, 212, 0.25);
  --selection-bg: rgba(90, 159, 212, 0.25);

  --glass-bg: rgba(0, 0, 0, 0.55);
  --glass-border: rgba(255, 255, 255, 0.14);
  --logo-filter: brightness(0) invert(1);
  
  --shadow-sm: none;
  --shadow-md: none;
  --shadow-lg: none;
  --shadow-xl: none;
  --shadow-xs: none;
}

/* === HIGH CONTRAST (LIGHT) === */
:root[data-theme="hc-light"],
:root[data-theme="contrast"],
body.theme-hc-light,
body.theme-contrast {
  color-scheme: light;
  --color-primary: #0057d9;
  --color-primary-dark: #003d99;
  --color-primary-light: #1a75ff;
  
  --color-secondary: #595959;
  --color-secondary-dark: #333333;
  --color-secondary-light: #808080;
  
  --color-accent: #6200ea;
  --color-accent-dark: #4500a8;
  --color-accent-light: #8033ff;
  
  --color-success: #008000;
  --color-warning: #ff8c00;
  --color-danger: #dc143c;
  --color-info: #0066cc;
  
  --bg-primary: #ffffff;
  --bg-secondary: #f0f0f0;
  --bg-tertiary: #e0e0e0;
  --bg-paper: #ffffff;
  --bg-elevated: #ffffff;
  
  --text-primary: #000000;
  --text-secondary: #333333;
  --text-muted: #666666;
  --text-disabled: #999999;
  --text-inverse: #ffffff;
  
  --border-light: #cccccc;
  --border-default: #999999;
  --border-dark: #666666;
  
  --hover-overlay: rgba(0, 0, 0, 0.1);
  --focus-ring: rgba(0, 87, 217, 0.5);
  --selection-bg: rgba(0, 87, 217, 0.3);

  --shadow-sm: none;
  --shadow-md: none;
  --shadow-lg: none;
  --shadow-xl: none;
  --shadow-xs: none;
  --logo-filter: invert(0);
}

/* === HIGH CONTRAST (DARK) === */
:root[data-theme="hc-dark"],
body.theme-hc-dark {
  color-scheme: dark;
  --color-primary: #66b3ff;
  --color-primary-dark: #99ccff;
  --color-primary-light: #cce6ff;

  --color-secondary: #e0e0e0;
  --color-secondary-dark: #ffffff;
  --color-secondary-light: #b3b3b3;

  --color-accent: #66b3ff;
  --color-accent-dark: #99ccff;
  --color-accent-light: #cce6ff;

  --color-success: #66cc77;
  --color-warning: #ffcc66;
  --color-danger: #ff6666;
  --color-info: #66b3ff;

  --bg-primary: #000000;
  --bg-secondary: #1a1a1a;
  --bg-tertiary: #2a2a2a;
  --bg-paper: #000000;
  --bg-elevated: #1a1a1a;

  --text-primary: #ffffff;
  --text-secondary: #e0e0e0;
  --text-muted: #b3b3b3;
  --text-disabled: #808080;
  --text-inverse: #000000;

  --border-light: rgba(255, 255, 255, 0.65);
  --border-default: rgba(255, 255, 255, 0.85);
  --border-dark: #ffffff;

  --hover-overlay: rgba(255, 255, 255, 0.08);
  --focus-ring: rgba(102, 179, 255, 0.6);
  --selection-bg: rgba(102, 179, 255, 0.35);

  --shadow-sm: none;
  --shadow-md: none;
  --shadow-lg: none;
  --shadow-xl: none;
  --shadow-xs: none;
  --logo-filter: brightness(0) invert(1);
}

/* === COLORBLIND SAFE THEME === */
:root[data-theme="colorblind"],
body.theme-colorblind {
  color-scheme: light;
  --color-primary: #1464a0;
  --color-primary-dark: #0f4f7d;
  --color-primary-light: #1b7ac7;
  
  --color-secondary: #676767;
  --color-secondary-dark: #4a4a4a;
  --color-secondary-light: #848484;
  
  --color-accent: #cc79a7;
  --color-accent-dark: #b85c8a;
  --color-accent-light: #de96c4;
  
  --color-success: #009e73;
  --color-warning: #e69f00;
  --color-danger: #b24e00;
  --color-info: #56b4e9;
  
  --bg-primary: #fafafa;
  --bg-secondary: #f0f0f0;
  --bg-tertiary: #e6e6e6;
  --bg-paper: #ffffff;
  --bg-elevated: #ffffff;
  
  --text-primary: #1a1a1a;
  --text-secondary: #404040;
  --text-muted: #666666;
  --text-disabled: #999999;
  --text-inverse: #ffffff;
  
  --border-light: #e0e0e0;
  --border-default: #cccccc;
  --border-dark: #b3b3b3;
  
  --hover-overlay: rgba(0, 0, 0, 0.06);
  --focus-ring: rgba(1, 115, 178, 0.3);
  --selection-bg: rgba(1, 115, 178, 0.2);

  --shadow-xs: none;
  --shadow-sm: none;
  --shadow-md: none;
  --shadow-lg: none;
  --shadow-xl: none;
  --logo-filter: invert(0);
}

/* =====================================================
   BASE STYLES
   ===================================================== */

* {
  box-sizing: border-box;
}

*::before,
*::after {
  box-sizing: inherit;
}

[hidden] {
  display: none !important;
}

html {
  font-size: 16px;
  color-scheme: light;
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: background-color var(--transition-base), color var(--transition-base);
}

textarea {
  resize: none;
}

/* Selection */
::selection {
  background-color: var(--selection-bg);
  color: var(--text-primary);
}

/* Focus Styles */
:focus {
  outline: none;
}

:focus-visible {
  outline: 3px solid var(--focus-ring);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  left: -10000px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

.skip-link:focus {
  position: fixed;
  left: var(--spacing-4);
  top: var(--spacing-4);
  z-index: 10000;
  width: auto;
  height: auto;
  padding: var(--spacing-3) var(--spacing-6);
  background-color: var(--color-primary);
  color: var(--text-inverse);
  text-decoration: none;
  border-radius: var(--radius-md);
  font-weight: 600;
}

/* =====================================================
   TYPOGRAPHY
   ===================================================== */

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--spacing-4);
  font-weight: 600;
  line-height: var(--line-height-tight);
  color: var(--text-primary);
}

.display-1 {
  font-size: var(--font-size-5xl);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.display-2 {
  font-size: var(--font-size-4xl);
  font-weight: 600;
  letter-spacing: -0.01em;
}

.display-3 {
  font-size: var(--font-size-3xl);
  font-weight: 600;
}

h1 { font-size: var(--font-size-3xl); }
h2 { font-size: var(--font-size-2xl); }
h3 { font-size: var(--font-size-xl); }
h4 { font-size: var(--font-size-lg); }
h5 { font-size: var(--font-size-base); }
h6 { font-size: var(--font-size-sm); }

p {
  margin: 0 0 var(--paragraph-spacing);
  line-height: var(--line-height-relaxed);
}

.lead {
  font-size: var(--font-size-lg);
  line-height: var(--line-height-relaxed);
  color: var(--text-secondary);
}

.body-text {
  max-width: var(--reading-max-width);
}

.caption {
  font-size: var(--font-size-sm);
  color: var(--text-muted);
  margin-top: var(--spacing-2);
}

/* Links */
a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

/* Code */
code {
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  padding: var(--spacing-1) var(--spacing-2);
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
}

pre {
  margin: 0 0 var(--spacing-6);
  padding: var(--spacing-4);
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-lg);
  overflow-x: auto;
}

pre code {
  padding: 0;
  background: none;
  font-size: var(--font-size-sm);
  line-height: var(--line-height-relaxed);
}

/* Lists */
ul, ol {
  margin: 0 0 var(--spacing-6);
  padding-left: var(--spacing-8);
  line-height: var(--line-height-relaxed);
}

li {
  margin-bottom: var(--spacing-2);
}

/* Blockquote */
blockquote {
  margin: var(--spacing-8) 0;
  padding: var(--spacing-4) var(--spacing-6);
  border-left: 4px solid var(--color-primary);
  background-color: var(--bg-secondary);
  border-radius: var(--radius-md);
  font-style: italic;
}

blockquote cite {
  display: block;
  margin-top: var(--spacing-3);
  font-style: normal;
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

/* =====================================================
   LAYOUT COMPONENTS
   ===================================================== */

.paper-container {
  width: 100%;
  max-width: var(--page-max);
  margin: 0 auto;
  padding: 0 var(--spacing-6);
}

.paper-section {
  padding: var(--spacing-16) 0;
}

.section-title {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--spacing-4);
  text-align: center;
}

.section-description {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  text-align: center;
  max-width: var(--reading-max-width);
  margin: 0 auto var(--spacing-12);
}

.paper-docs {
  padding: var(--spacing-12) 0 var(--spacing-20);
}

.paper-docs-layout {
  align-items: start;
}

.paper-docs-content {
  min-width: 0;
  padding: 0 var(--spacing-6);
}

.paper-docs .section {
  margin-bottom: var(--space-8);
}

.paper-docs .section:last-child {
  margin-bottom: 0;
}

.paper-docs .section .subsection {
  margin-top: var(--space-8);
}

.paper-docs .paper-section {
  padding: var(--spacing-12) 0;
}

.paper-docs .section-title {
  text-align: left;
  font-size: var(--font-size-2xl);
  margin-bottom: var(--spacing-2);
}

.paper-docs .section-description {
  text-align: left;
  font-size: var(--font-size-base);
  max-width: none;
  margin: 0 0 var(--spacing-8);
}

/* Grid Layout */
.grid-layout {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(300px, 100%), 1fr));
  gap: var(--spacing-6);
  margin-bottom: var(--spacing-8);
}

.paper-panel {
  background-color: var(--bg-paper);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: var(--spacing-6);
}

.paper-panel h3 {
  margin-bottom: var(--spacing-2);
}

.paper-panel p {
  color: var(--text-secondary);
}

.paper-list {
  margin: 0;
  padding-left: 18px;
}

/* Layout Modes (Horizon v2 compatible) */
.layout-mode-controls {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--spacing-2);
  margin: var(--spacing-6) 0 var(--spacing-8);
}

.layout-mode-btn {
  padding: var(--spacing-2) var(--spacing-4);
  border-color: var(--border-default);
  color: var(--muted-foreground);
}

.layout-mode-btn[aria-pressed="false"]:hover {
  border-color: var(--text-primary);
  background-color: var(--hover-overlay);
  color: var(--text-primary);
}

.layout-mode-btn[aria-pressed="true"]:hover {
  background-color: var(--text-primary);
  border-color: var(--text-primary);
  color: var(--bg-primary);
}

.layout-mode-btn[aria-pressed="true"] {
  background-color: var(--text-primary);
  border-color: var(--text-primary);
  color: var(--bg-primary);
}

.layout-mode-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(260px, 100%), 1fr));
  gap: var(--spacing-6);
}

.layout-mode-card {
  background-color: var(--bg-paper);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: var(--spacing-6);
}

.layout-mode-card h3 {
  margin-bottom: var(--spacing-2);
}

.layout-mode-card p {
  margin-bottom: var(--spacing-4);
  color: var(--text-secondary);
}

.layout-mode-mini-viewport {
  height: 72px;
  width: 100%;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
  background-color: var(--bg-tertiary);
  padding: var(--spacing-2);
  display: flex;
  align-items: stretch;
}

.layout-mode-mini-container {
  height: 100%;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-default);
  background-color: var(--bg-paper);
  margin: 0 auto;
  width: 100%;
}

.layout-mode-mini-container--docs {
  width: 78%;
}

.layout-mode-mini-container--centered {
  width: 62%;
}

.layout-mode-mini-container--content {
  width: 100%;
}

/* =====================================================
   COMPONENTS
   ===================================================== */

/* === Cards - NYTimes Style === */
.paper-card {
  background-color: transparent;
  border: none;
  border-radius: 0;
  padding: var(--spacing-6) 0;
  transition: none;
  border-bottom: 1px solid var(--border-light);
}

.paper-card:last-child {
  border-bottom: none;
}

.paper-card-bordered {
  border: 1px solid var(--border-default);
  padding: var(--spacing-6);
}

.interactive-card {
  cursor: pointer;
  position: relative;
  padding-bottom: var(--spacing-6);
  border-bottom: 2px solid transparent;
  transition: border-color var(--transition-fast);
}

.interactive-card:hover {
  border-bottom-color: var(--text-primary);
}

.feature-card {
  text-align: center;
}

.card-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 64px;
  height: 64px;
  margin-bottom: var(--spacing-4);
  background-color: var(--bg-secondary);
  border-radius: var(--radius-2xl);
  color: var(--color-primary);
}

.card-icon .hz-icon {
  font-size: 32px;
}

/* === Buttons (Horizon v2 core) === */
/* Paper skin: square corners by default */
.btn,
.btn-outline,
.btn-ghost,
.btn-glass,
.icon-btn {
  border-radius: 0;
}

/* === Forms === */
.form-group {
  margin-bottom: var(--spacing-6);
}

.form-group label {
  display: block;
  margin-bottom: var(--spacing-2);
  font-weight: 500;
  color: var(--text-primary);
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: var(--spacing-3) var(--spacing-4);
  font-family: inherit;
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--text-primary);
  background-color: transparent;
  border: none;
  /* Reserve the active underline so control height stays stable in every state. */
  border-bottom: 2px solid var(--text-primary);
  border-radius: 0;
  transition: border-color var(--transition-fast), background-color var(--transition-fast), color var(--transition-fast);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  border-color: var(--color-primary);
  outline: none;
}

:is(.form-input, .form-select, .form-textarea):focus-visible {
  outline: 2px solid var(--ring);
  outline-offset: var(--spacing-1);
}

:is(.form-input, .form-select, .form-textarea)[aria-invalid="true"] {
  border-color: var(--color-danger);
}

.form-textarea {
  resize: none;
  min-height: 120px;
  overflow-y: auto;
}

/* === Theme Switcher === */
.theme-switcher {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-1);
  background-color: var(--bg-tertiary);
  padding: var(--spacing-1);
  border-radius: 0;
  border: 1px solid var(--border-default);
}

.theme-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background-color: transparent;
  border: none;
  border-radius: 0;
  color: var(--muted-foreground);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.theme-btn:hover {
  background-color: var(--bg-primary);
  color: var(--text-primary);
}

.theme-btn.active {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  box-shadow: 0 0 0 1px var(--border-default);
}

/* === Header - NYTimes Style === */
.paper-header {
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--text-primary);
  border-top: 4px solid var(--text-primary);
  position: sticky;
  top: 0;
  z-index: 100;
}

.paper-header-shell {
  max-width: var(--paper-header-max);
}

.paper-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--paper-header-pad-y) 0;
  gap: var(--paper-header-gap);
  flex-wrap: nowrap;
  min-width: 0;
}

.paper-nav-left {
  display: flex;
  align-items: center;
  gap: var(--paper-header-gap);
  min-width: 0;
  flex: 1 1 0;
}

.paper-nav-divider {
  width: 1px;
  height: 24px;
  background-color: var(--border-default);
  flex: 0 0 auto;
}

.paper-nav-meta {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  min-width: 0;
  flex: 0 1 auto;
}

.paper-nav-product {
  font-weight: 600;
  color: var(--text-primary);
  font-size: var(--font-size-sm);
  letter-spacing: 0.01em;
}

.paper-logo-img {
  width: auto;
  height: var(--spacing-6);
  max-width: 140px;
  display: block;
  filter: var(--logo-filter, none);
  transition: filter var(--transition-fast);
}

.paper-nav-right {
  display: flex;
  align-items: center;
  gap: var(--paper-header-gap);
  min-width: 0;
  flex: 0 0 auto;
  margin-left: var(--paper-header-gap);
  flex-wrap: nowrap;
}

.paper-icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  padding: 0;
  border: 1px solid var(--border-default);
  border-radius: 0;
  background-color: transparent;
  color: var(--muted-foreground);
  cursor: pointer;
  transition: background-color var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
}

.paper-icon-btn:hover {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  border-color: var(--text-primary);
}

.paper-icon-btn:active {
  transform: translateY(0.5px);
}

#mobileMenuBtn {
  display: none;
}

.nav-logo {
  display: flex;
  align-items: center;
  flex: 0 0 auto;
  gap: var(--spacing-2);
  font-weight: 700;
  font-size: var(--font-size-lg);
  color: var(--text-primary);
  letter-spacing: -0.02em;
  line-height: 0;
}

.nav-logo:hover {
  text-decoration: none;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--paper-header-gap);
  white-space: nowrap;
}

.nav-links a {
  color: var(--text-secondary);
  font-weight: 500;
  font-size: var(--font-size-sm);
  padding: var(--spacing-1) var(--spacing-2);
  border-radius: var(--radius-md);
}

.paper-header .theme-switcher {
  padding: 3px;
  gap: 3px;
}

.paper-header .theme-btn {
  width: 30px;
  height: 30px;
}

.nav-links a:hover {
  color: var(--text-primary);
  text-decoration: none;
  background-color: var(--hover-overlay);
}

.nav-links a.active {
  color: var(--text-primary);
  background-color: var(--hover-overlay);
}

@media (max-width: 1024px) {
  .nav-links {
    display: none;
  }

  #mobileMenuBtn {
    display: inline-flex;
  }

  .paper-docs {
    padding-left: var(--spacing-4);
    padding-right: var(--spacing-4);
  }

  .paper-docs-layout {
    display: block;
  }

  .paper-docs-content {
    padding: 0;
  }
}

@media (max-width: 480px) {
  .paper-nav {
    flex-wrap: wrap;
    gap: var(--spacing-3);
  }

  .paper-nav-right {
    width: auto;
    justify-content: space-between;
    margin-left: 0;
  }

  .paper-nav-meta .tag {
    display: none;
  }
}

/* Mobile sidebar (docs) */
.paper-mobile-sidebar {
  display: none;
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: min(320px, 92vw);
  background-color: var(--bg-primary);
  border-left: 1px solid var(--border-default);
  transform: translateX(100%);
  transition: transform var(--transition-base);
  z-index: 1001;
}

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

.paper-mobile-sidebar__inner {
  height: 100%;
  overflow: auto;
  padding: var(--spacing-6);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-6);
}

.paper-mobile-sidebar__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-4);
  padding-bottom: var(--spacing-4);
  border-bottom: 1px solid var(--border-light);
}

.paper-mobile-sidebar__title {
  font-weight: 700;
}

.paper-mobile-sidebar__section-title {
  font-size: var(--font-size-xs);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 700;
  margin-bottom: var(--spacing-2);
}

.paper-sidebar-link {
  display: block;
  padding: var(--spacing-2) var(--spacing-3);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  text-decoration: none;
}

.paper-sidebar-link:hover {
  color: var(--text-primary);
  background-color: var(--hover-overlay);
  text-decoration: none;
}

.paper-sidebar-link.active {
  color: var(--color-primary);
  background-color: var(--hover-overlay);
  font-weight: 600;
}

.paper-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.35);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-base);
  z-index: 1000;
}

.paper-backdrop.open {
  opacity: 1;
  pointer-events: auto;
}

/* Hide Horizon v2 visual background demos inside Paper */
.paper-docs #glass,
.paper-docs #backgrounds {
  display: none !important;
}

.paper-mobile-theme {
  display: none;
  margin: 0;
  padding: 0;
  border: 0;
}

@media (max-width: 1024px) {
  .paper-mobile-sidebar {
    display: block;
  }

  .js .paper-docs .toc-sidebar {
    display: none;
  }
}

/* === Hero Section === */
.paper-hero {
  background-color: var(--bg-secondary);
  padding: var(--spacing-16) 0;
}

.paper-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  gap: var(--spacing-10);
  align-items: start;
}

.paper-hero-copy .hero-title,
.paper-hero-copy .hero-subtitle,
.paper-hero-copy .hero-description {
  text-align: left;
}

.paper-hero-copy .hero-description {
  max-width: none;
  margin: 0;
}

.paper-hero-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  flex-wrap: wrap;
  margin-top: var(--spacing-6);
}

.paper-hero-preview-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-2);
  margin-bottom: var(--spacing-4);
}

.paper-hero-preview-title {
  margin-bottom: var(--spacing-4);
}

.paper-hero-preview-body {
  font-family: var(--font-serif);
  line-height: var(--line-height-relaxed);
}

.paper-hero-preview-card .article-callout {
  margin: var(--spacing-6) 0 0;
}

@media (max-width: 1024px) {
  .paper-hero-grid {
    grid-template-columns: 1fr;
  }
}

.hero-content {
  text-align: center;
  margin-bottom: var(--spacing-12);
}

.hero-title {
  font-size: var(--font-size-5xl);
  margin-bottom: var(--spacing-4);
}

.hero-subtitle {
  font-size: var(--font-size-2xl);
  color: var(--text-secondary);
  margin-bottom: var(--spacing-6);
}

.hero-description {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  max-width: var(--reading-max-width);
  margin: 0 auto;
  line-height: var(--line-height-relaxed);
}

.hero-demo {
  max-width: 600px;
  margin: 0 auto;
}

.demo-article {
  text-align: left;
}

/* === Color System === */
.color-showcase {
  margin-bottom: var(--spacing-12);
}

.color-showcase h3 {
  margin-bottom: var(--spacing-6);
}

.color-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(150px, 100%), 1fr));
  gap: var(--spacing-4);
  margin-bottom: var(--spacing-8);
}

.color-swatch {
  height: 120px;
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 500;
  border: 1px solid var(--border-light);
}

.color-name {
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-1);
}

.color-value {
  font-size: var(--font-size-xs);
  font-family: var(--font-mono);
  opacity: 0.8;
}

.text-color-showcase {
  background-color: var(--bg-paper);
  padding: var(--spacing-6);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
}

.text-sample {
  margin-bottom: var(--spacing-6);
  padding-bottom: var(--spacing-6);
  border-bottom: 1px solid var(--border-light);
}

.text-sample:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

/* === Typography Showcase === */
.typography-showcase {
  background-color: var(--bg-paper);
  padding: var(--spacing-8);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
}

.type-sample {
  margin-bottom: var(--spacing-8);
  padding-bottom: var(--spacing-8);
  border-bottom: 1px solid var(--border-light);
}

.type-sample:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

/* === Component Groups === */
.component-group {
  margin-bottom: var(--spacing-12);
}

.component-group h3 {
  margin-bottom: var(--spacing-6);
}

.button-showcase {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-3);
  padding: var(--spacing-6);
  background-color: var(--bg-paper);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
}

.demo-form {
  max-width: 500px;
  padding: var(--spacing-6);
  background-color: var(--bg-paper);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
}

/* === Interactive Elements === */
.interactive-showcase {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(250px, 100%), 1fr));
  gap: var(--spacing-6);
}

.interactive-showcase > div {
  padding: var(--spacing-6);
  background-color: var(--bg-paper);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
}

.interactive-showcase h4 {
  margin-bottom: var(--spacing-4);
}

/* Reading Progress Bar */
.reading-progress {
  width: 100%;
  height: 4px;
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-top: var(--spacing-4);
}

.progress-bar {
  height: 100%;
  background-color: var(--color-primary);
  transition: width var(--transition-slow);
}

/* Toggle Switch */
.toggle-switch {
  display: inline-flex;
  align-items: center;
  cursor: pointer;
  user-select: none;
}

.toggle-switch input {
  position: absolute;
  opacity: 0;
}

.toggle-slider {
  position: relative;
  width: 48px;
  height: 24px;
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-full);
  transition: background-color var(--transition-fast);
  margin-right: var(--spacing-3);
}

.toggle-slider::before {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  width: 20px;
  height: 20px;
  background-color: var(--bg-primary);
  border-radius: var(--radius-full);
  transition: transform var(--transition-fast);
  border: 1px solid var(--border-light);
}

.toggle-switch input:checked + .toggle-slider {
  background-color: var(--color-primary);
}

.toggle-switch input:checked + .toggle-slider::before {
  transform: translateX(24px);
}

.toggle-label {
  font-weight: 500;
}

/* Tooltip */
[data-tooltip] {
  position: relative;
}

[data-tooltip]::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(-8px);
  padding: var(--spacing-2) var(--spacing-3);
  background-color: var(--text-primary);
  color: var(--bg-primary);
  font-size: var(--font-size-sm);
  border-radius: var(--radius-md);
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-fast);
}

[data-tooltip]:hover::after {
  opacity: 1;
}

/* === Article Styles === */
.paper-article {
  max-width: var(--reading-max-width);
  margin: 0 auto;
  background-color: var(--bg-paper);
  padding: var(--spacing-8) var(--spacing-6);
  border-radius: 0;
  border: none;
}

.article-header {
  margin-bottom: var(--spacing-8);
  padding-bottom: var(--spacing-8);
  border-bottom: 1px solid var(--border-light);
}

.article-title {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--spacing-4);
}

.article-meta {
  display: flex;
  gap: var(--spacing-4);
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 500;
  padding-bottom: var(--spacing-4);
  border-bottom: 1px solid var(--border-light);
  margin-bottom: var(--spacing-6);
}

.article-meta span::after {
  content: '|';
  margin-left: var(--spacing-4);
  font-weight: 300;
}

.article-meta span:last-child::after {
  display: none;
}

.article-content h2 {
  margin-top: var(--spacing-16);
  margin-bottom: var(--spacing-4);
  font-family: var(--font-sans);
  font-weight: 700;
  border-bottom: 2px solid var(--text-primary);
  padding-bottom: var(--spacing-3);
}

.article-content h3 {
  margin-top: var(--spacing-10);
  margin-bottom: var(--spacing-3);
  font-family: var(--font-sans);
  font-weight: 500;
}

.article-content {
  font-family: var(--font-serif);
  font-size: var(--article-font-size);
  line-height: var(--article-line-height);
}

.article-content p {
  margin-bottom: var(--paragraph-spacing);
  color: var(--text-primary);
}

.article-content a {
  color: var(--color-primary);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

.article-content a:hover {
  text-decoration-thickness: 2px;
}

.article-quote {
  position: relative;
  padding-left: var(--spacing-6);
  margin: var(--spacing-10) 0;
  font-style: italic;
  color: var(--text-secondary);
  line-height: var(--line-height-loose);
}

.article-quote::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background-color: var(--text-primary);
}

.article-list {
  margin-bottom: var(--spacing-6);
}

.article-list li {
  margin-bottom: var(--spacing-3);
}

.article-callout {
  display: flex;
  gap: var(--spacing-4);
  padding: var(--spacing-4);
  background-color: var(--bg-secondary);
  border-radius: var(--radius-lg);
  border-left: 4px solid var(--color-info);
  margin: var(--spacing-8) 0;
}

.article-callout .hz-icon {
  color: var(--color-info);
  flex-shrink: 0;
}

.article-footer {
  margin-top: var(--spacing-12);
  padding-top: var(--spacing-8);
  border-top: 1px solid var(--border-light);
}

.article-tags {
  display: flex;
  gap: var(--spacing-2);
  flex-wrap: wrap;
}

.tag {
  padding: var(--spacing-2) var(--spacing-3);
  background-color: transparent;
  color: var(--text-primary);
  font-size: var(--font-size-sm);
  border-radius: 0;
  border: 1px solid var(--text-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 500;
}

/* === Accessibility Features === */
.accessibility-features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(300px, 100%), 1fr));
  gap: var(--spacing-6);
  margin-bottom: var(--spacing-8);
}

.contrast-demo {
  margin-top: var(--spacing-4);
}

.contrast-sample {
  padding: var(--spacing-4);
  border-radius: var(--radius-md);
  font-weight: 500;
  text-align: center;
}

.focus-demo {
  margin-top: var(--spacing-4);
}

.aria-example {
  display: inline-block;
  margin-top: var(--spacing-2);
  padding: var(--spacing-2) var(--spacing-3);
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
}

.accessibility-checklist {
  background-color: var(--bg-paper);
  padding: var(--spacing-6);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
}

.checklist {
  list-style: none;
  padding: 0;
}

.checklist li {
  padding: var(--spacing-3) 0;
  border-bottom: 1px solid var(--border-light);
  color: var(--text-secondary);
}

.checklist li:last-child {
  border-bottom: none;
}

.checklist li.checked {
  color: var(--color-success);
  font-weight: 500;
}

/* === Footer === */
.paper-footer {
  background-color: var(--bg-secondary);
  margin-top: var(--spacing-20);
  padding: var(--spacing-12) 0 var(--spacing-6);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(250px, 100%), 1fr));
  gap: var(--spacing-8);
  margin-bottom: var(--spacing-8);
}

.footer-section h4 {
  margin-bottom: var(--spacing-4);
}

.footer-section ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-section li {
  margin-bottom: var(--spacing-2);
}

.footer-section a {
  color: var(--text-secondary);
}

.footer-section a:hover {
  color: var(--text-primary);
}

.footer-bottom {
  padding-top: var(--spacing-6);
  border-top: 1px solid var(--border-light);
  text-align: center;
  color: var(--text-muted);
  font-size: var(--font-size-sm);
}

/* =====================================================
   RESPONSIVE DESIGN
   ===================================================== */

@media (max-width: 768px) {
  :root {
    --font-size-5xl: 2.5rem;
    --font-size-4xl: 2rem;
    --font-size-3xl: 1.5rem;
  }
  
  .paper-container {
    padding: 0 var(--spacing-4);
  }
  .paper-container.paper-docs {
    padding: var(--spacing-12) var(--spacing-4) var(--spacing-16);
  }
  .paper-docs-content {
    padding: 0;
  }
  .paper-nav-right > .theme-switcher {
    display: none;
  }
  .paper-mobile-theme {
    display: flex;
    padding: 0;
    margin: 0;
    border: 0;
    justify-content: flex-start;
  }
  .paper-mobile-theme .theme-switcher {
    display: flex;
    justify-content: flex-start;
    width: auto;
    box-sizing: border-box;
    gap: var(--spacing-1);
  }
  
  .paper-section {
    padding: var(--spacing-12) 0;
  }
  
  .grid-layout {
    grid-template-columns: 1fr;
  }
  
  .nav-links {
    display: none;
  }
  
  .hero-title {
    font-size: var(--font-size-4xl);
  }
  
  .hero-subtitle {
    font-size: var(--font-size-xl);
  }
  
  .color-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .article-meta {
    flex-wrap: wrap;
  }
  
  .paper-article {
    padding: var(--spacing-4) var(--spacing-3);
  }
}

/* === Reduced Motion === */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* === Print Styles === */
@media print {
  .theme-switcher,
  .paper-header,
  .paper-footer {
    display: none;
  }
  
  body {
    color: black;
    background: white;
  }
  
  .paper-card {
    border: 1px solid #ddd;
  }
  
  a {
    color: black;
    text-decoration: underline;
  }
}

/* =====================================================
   FLEX GRID SYSTEM - 12 Column Base
   ===================================================== */

.container {
  width: 100%;
  max-width: var(--container-xl);
  margin: 0 auto;
  padding: 0 var(--spacing-4);
}

.container-fluid {
  width: 100%;
  padding: 0 var(--spacing-4);
}

.container-reading {
  width: 100%;
  max-width: var(--reading-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-4);
}

/* Flex Row */
.row {
  display: flex;
  flex-wrap: wrap;
  margin-left: calc(var(--spacing-4) * -1);
  margin-right: calc(var(--spacing-4) * -1);
}

.row-no-gutters {
  margin-left: 0;
  margin-right: 0;
}

.row-no-gutters > [class*="col-"] {
  padding-left: 0;
  padding-right: 0;
}

/* Column Base */
[class*="col-"] {
  position: relative;
  width: 100%;
  padding-left: var(--spacing-4);
  padding-right: var(--spacing-4);
}

/* 12-Column Grid */
.col-1 { flex: 0 0 8.333333%; max-width: 8.333333%; }
.col-2 { flex: 0 0 16.666667%; max-width: 16.666667%; }
.col-3 { flex: 0 0 25%; max-width: 25%; }
.col-4 { flex: 0 0 33.333333%; max-width: 33.333333%; }
.col-5 { flex: 0 0 41.666667%; max-width: 41.666667%; }
.col-6 { flex: 0 0 50%; max-width: 50%; }
.col-7 { flex: 0 0 58.333333%; max-width: 58.333333%; }
.col-8 { flex: 0 0 66.666667%; max-width: 66.666667%; }
.col-9 { flex: 0 0 75%; max-width: 75%; }
.col-10 { flex: 0 0 83.333333%; max-width: 83.333333%; }
.col-11 { flex: 0 0 91.666667%; max-width: 91.666667%; }
.col-12 { flex: 0 0 100%; max-width: 100%; }

.col-auto { flex: 0 0 auto; width: auto; max-width: 100%; }
.col { flex: 1 0 0%; }

/* Responsive Columns */
@media (min-width: 576px) {
  .col-sm-1 { flex: 0 0 8.333333%; max-width: 8.333333%; }
  .col-sm-2 { flex: 0 0 16.666667%; max-width: 16.666667%; }
  .col-sm-3 { flex: 0 0 25%; max-width: 25%; }
  .col-sm-4 { flex: 0 0 33.333333%; max-width: 33.333333%; }
  .col-sm-5 { flex: 0 0 41.666667%; max-width: 41.666667%; }
  .col-sm-6 { flex: 0 0 50%; max-width: 50%; }
  .col-sm-7 { flex: 0 0 58.333333%; max-width: 58.333333%; }
  .col-sm-8 { flex: 0 0 66.666667%; max-width: 66.666667%; }
  .col-sm-9 { flex: 0 0 75%; max-width: 75%; }
  .col-sm-10 { flex: 0 0 83.333333%; max-width: 83.333333%; }
  .col-sm-11 { flex: 0 0 91.666667%; max-width: 91.666667%; }
  .col-sm-12 { flex: 0 0 100%; max-width: 100%; }
}

@media (min-width: 768px) {
  .col-md-1 { flex: 0 0 8.333333%; max-width: 8.333333%; }
  .col-md-2 { flex: 0 0 16.666667%; max-width: 16.666667%; }
  .col-md-3 { flex: 0 0 25%; max-width: 25%; }
  .col-md-4 { flex: 0 0 33.333333%; max-width: 33.333333%; }
  .col-md-5 { flex: 0 0 41.666667%; max-width: 41.666667%; }
  .col-md-6 { flex: 0 0 50%; max-width: 50%; }
  .col-md-7 { flex: 0 0 58.333333%; max-width: 58.333333%; }
  .col-md-8 { flex: 0 0 66.666667%; max-width: 66.666667%; }
  .col-md-9 { flex: 0 0 75%; max-width: 75%; }
  .col-md-10 { flex: 0 0 83.333333%; max-width: 83.333333%; }
  .col-md-11 { flex: 0 0 91.666667%; max-width: 91.666667%; }
  .col-md-12 { flex: 0 0 100%; max-width: 100%; }
}

@media (min-width: 1024px) {
  .col-lg-1 { flex: 0 0 8.333333%; max-width: 8.333333%; }
  .col-lg-2 { flex: 0 0 16.666667%; max-width: 16.666667%; }
  .col-lg-3 { flex: 0 0 25%; max-width: 25%; }
  .col-lg-4 { flex: 0 0 33.333333%; max-width: 33.333333%; }
  .col-lg-5 { flex: 0 0 41.666667%; max-width: 41.666667%; }
  .col-lg-6 { flex: 0 0 50%; max-width: 50%; }
  .col-lg-7 { flex: 0 0 58.333333%; max-width: 58.333333%; }
  .col-lg-8 { flex: 0 0 66.666667%; max-width: 66.666667%; }
  .col-lg-9 { flex: 0 0 75%; max-width: 75%; }
  .col-lg-10 { flex: 0 0 83.333333%; max-width: 83.333333%; }
  .col-lg-11 { flex: 0 0 91.666667%; max-width: 91.666667%; }
  .col-lg-12 { flex: 0 0 100%; max-width: 100%; }
}

/* Flex Utilities */
.d-flex { display: flex !important; }
.d-inline-flex { display: inline-flex !important; }

.flex-row { flex-direction: row !important; }
.flex-column { flex-direction: column !important; }
.flex-row-reverse { flex-direction: row-reverse !important; }
.flex-column-reverse { flex-direction: column-reverse !important; }

.flex-wrap { flex-wrap: wrap !important; }
.flex-nowrap { flex-wrap: nowrap !important; }
.flex-wrap-reverse { flex-wrap: wrap-reverse !important; }

.justify-content-start { justify-content: flex-start !important; }
.justify-content-end { justify-content: flex-end !important; }
.justify-content-center { justify-content: center !important; }
.justify-content-between { justify-content: space-between !important; }
.justify-content-around { justify-content: space-around !important; }
.justify-content-evenly { justify-content: space-evenly !important; }

.align-items-start { align-items: flex-start !important; }
.align-items-end { align-items: flex-end !important; }
.align-items-center { align-items: center !important; }
.align-items-baseline { align-items: baseline !important; }
.align-items-stretch { align-items: stretch !important; }

.align-self-auto { align-self: auto !important; }
.align-self-start { align-self: flex-start !important; }
.align-self-end { align-self: flex-end !important; }
.align-self-center { align-self: center !important; }
.align-self-baseline { align-self: baseline !important; }
.align-self-stretch { align-self: stretch !important; }

.flex-fill { flex: 1 1 auto !important; }
.flex-grow-0 { flex-grow: 0 !important; }
.flex-grow-1 { flex-grow: 1 !important; }
.flex-shrink-0 { flex-shrink: 0 !important; }
.flex-shrink-1 { flex-shrink: 1 !important; }

/* Gap Utilities */
.gap-1 { gap: var(--spacing-1) !important; }
.gap-2 { gap: var(--spacing-2) !important; }
.gap-3 { gap: var(--spacing-3) !important; }
.gap-4 { gap: var(--spacing-4) !important; }
.gap-5 { gap: var(--spacing-5) !important; }
.gap-6 { gap: var(--spacing-6) !important; }
.gap-8 { gap: var(--spacing-8) !important; }

/* =====================================================
   READING LAYOUT PATTERNS
   ===================================================== */

/* Magazine Layout - Grid Lines */
.layout-magazine {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 0;
  border-top: 1px solid var(--text-primary);
}

.layout-magazine .feature-article {
  grid-column: span 8;
  padding-right: var(--spacing-8);
  border-right: 1px solid var(--border-default);
}

.layout-magazine .sidebar {
  grid-column: span 4;
  padding-left: var(--spacing-8);
}

/* Newspaper Layout - Column Rules */
.layout-newspaper {
  columns: 3;
  column-gap: var(--spacing-8);
  column-rule: 1px solid var(--text-primary);
  padding-top: var(--spacing-6);
  border-top: 1px solid var(--text-primary);
}

.layout-newspaper > * {
  break-inside: avoid;
  margin-bottom: var(--spacing-6);
}

/* Blog Layout - Grid Structure */
.layout-blog {
  display: flex;
  gap: 0;
  border-top: 1px solid var(--text-primary);
  padding-top: var(--spacing-6);
}

.layout-blog .content {
  flex: 1;
  max-width: var(--reading-max-width);
  padding-right: var(--spacing-8);
  border-right: 1px solid var(--border-default);
}

.layout-blog .sidebar {
  flex: 0 0 300px;
  padding-left: var(--spacing-8);
}

/* Card Grid Layout - Grid Lines */
.layout-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(300px, 100%), 1fr));
  gap: 1px;
  background-color: var(--border-default);
  border: 1px solid var(--border-default);
}

.layout-cards > * {
  background-color: var(--bg-primary);
  padding: var(--spacing-6);
}

/* Reading Focus Layout */
.layout-reading-focus {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--spacing-8) 0;
}

.layout-reading-focus .content {
  width: 100%;
  max-width: var(--reading-max-width);
}

.layout-reading-focus .meta {
  width: 100%;
  max-width: 960px;
  margin-bottom: var(--spacing-8);
}

/* Split Screen Layout */
.layout-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: 100vh;
}

.layout-split > * {
  padding: var(--spacing-8);
  overflow-y: auto;
}

/* Sidebar Layouts - With Dividers */
.layout-sidebar-left {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 0;
}

.layout-sidebar-left > :first-child {
  padding-right: var(--spacing-8);
  border-right: 1px solid var(--border-default);
}

.layout-sidebar-left > :last-child {
  padding-left: var(--spacing-8);
}

.layout-sidebar-right {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 0;
}

.layout-sidebar-right > :first-child {
  padding-right: var(--spacing-8);
  border-right: 1px solid var(--border-default);
}

.layout-sidebar-right > :last-child {
  padding-left: var(--spacing-8);
}

/* Layout Mode: Centered (no sidebar) */
:root[data-layout="centered"] .layout-sidebar-left {
  grid-template-columns: 1fr;
}

:root[data-layout="centered"] .layout-sidebar-left > :first-child {
  display: none;
  padding-right: 0;
  border-right: 0;
}

:root[data-layout="centered"] .layout-sidebar-left > :last-child {
  padding-left: 0;
}

:root[data-layout="centered"] #mobileMenuBtn {
  display: none !important;
}

:root[data-layout="centered"] #mobileSidebar,
:root[data-layout="centered"] #mobileSidebarBackdrop {
  display: none !important;
}

/* Digital Reading Components */
.paper-header .reading-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background-color: transparent;
  border-radius: 0;
  margin: 0;
  pointer-events: none;
}

.paper-header .reading-progress .progress-bar {
  height: 100%;
  background-color: var(--text-primary);
  width: 0;
  transition: width 150ms ease;
  border-radius: 0;
}

.reading-progress-bar {
  height: 100%;
  background-color: var(--text-primary);
  width: 0;
  transition: width 150ms ease;
}

.reading-time {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-2);
  color: var(--text-muted);
  font-size: var(--font-size-sm);
}

.chapter-navigation {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-6) 0;
  border-top: 1px solid var(--border-light);
  margin-top: var(--spacing-12);
}

.toc-sidebar {
  position: sticky;
  top: calc(var(--spacing-6) + 60px);
  max-height: calc(100vh - 120px);
  overflow-y: auto;
}

.toc-sidebar nav {
  padding-left: 0;
  border-left: 1px solid var(--text-primary);
}

.paper-toc-group + .paper-toc-group {
  margin-top: var(--spacing-6);
}

.paper-toc-title {
  margin: 0 0 var(--spacing-2) var(--spacing-4);
  font-size: var(--font-size-xs);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 600;
}

.toc-sidebar a {
  display: block;
  padding: var(--spacing-2) var(--spacing-4);
  color: var(--text-secondary);
  text-decoration: none;
  transition: all var(--transition-fast);
  border-left: 2px solid transparent;
  margin-left: -2px;
}

.toc-sidebar a:hover {
  color: var(--text-primary);
  background-color: var(--hover-overlay);
}

.toc-sidebar a.active {
  color: var(--color-primary);
  border-left-color: var(--color-primary);
  font-weight: 500;
}

/* Responsive Reading Layouts */
@media (max-width: 1024px) {
  .layout-magazine {
    grid-template-columns: 1fr;
  }
  
  .layout-magazine .feature-article,
  .layout-magazine .sidebar {
    grid-column: span 1;
  }
  
  .layout-newspaper {
    columns: 2;
  }
  
  .layout-blog {
    flex-direction: column;
  }
  
  .layout-blog .sidebar {
    flex: 1;
    max-width: 100%;
  }
  
  .layout-sidebar-left,
  .layout-sidebar-right {
    grid-template-columns: 1fr;
  }

  .layout-sidebar-left > :first-child,
  .layout-sidebar-left > :last-child,
  .layout-sidebar-right > :first-child,
  .layout-sidebar-right > :last-child {
    padding-left: 0;
    padding-right: 0;
    border-right: none;
  }
  
  .toc-sidebar {
    position: static;
    margin-bottom: var(--spacing-8);
    max-height: none;
  }
}

@media (max-width: 768px) {
  .layout-newspaper {
    columns: 1;
  }
  
  .layout-split {
    grid-template-columns: 1fr;
  }
  
  .layout-cards {
    grid-template-columns: 1fr;
  }
}

/* =====================================================
   DEMO AND SHOWCASE STYLES
   ===================================================== */

.demo-box {
  background-color: transparent;
  padding: var(--spacing-6) 0;
  border-radius: 0;
  margin-bottom: var(--spacing-8);
  border-top: 1px solid var(--border-default);
  border-bottom: 1px solid var(--border-default);
}

.paper-breakout {
  width: 100%;
  padding: var(--spacing-4);
  background-color: var(--bg-secondary);
  border: 1px dashed var(--border-default);
  border-radius: var(--radius-lg);
  overflow-x: auto;
}

.breakout-wide-grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(140px, 1fr));
  gap: var(--spacing-2);
  min-width: 920px;
}

.breakout-cell {
  padding: var(--spacing-2) var(--spacing-3);
  background-color: var(--bg-paper);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  color: var(--text-primary);
  white-space: nowrap;
}

.breakout-cell-head {
  background-color: var(--bg-tertiary);
  color: var(--text-secondary);
  font-weight: 600;
}

.demo-box .paper-card {
  margin-bottom: var(--spacing-4);
}

.demo-box .paper-card:last-child {
  margin-bottom: 0;
}

/* Section spacing utility */
.section-spacing {
  padding: var(--spacing-12) 0;
}

/* Material Symbols Outlined (Horizon v2 compatible) */
.hz-icon,
.material-symbols-outlined.hz-icon {
  font-family: "Material Symbols Outlined";
  font-variation-settings:
    "FILL" 0,
    "wght" 250,
    "GRAD" 0,
    "opsz" 40;
  font-size: 20px;
  line-height: 1;
  display: inline-block;
  vertical-align: middle;
}

/* Legacy Material Icons support (older pages) */
.material-icons {
  font-size: 20px;
  vertical-align: middle;
}

/* Enhanced tag styles - NYTimes style */
.tag:hover {
  background-color: var(--text-primary);
  color: var(--bg-primary);
}

/* =====================================================
   NYTimes Style Elements
   ===================================================== */

/* Section Dividers */
.section-divider {
  border: none;
  border-top: 1px solid var(--text-primary);
  margin: var(--spacing-12) 0;
  height: 0;
}

.section-divider.thick {
  border-top-width: 3px;
}

.section-divider.double {
  border-top: 3px double var(--text-primary);
}

/* Cutlines / Captions */
.cutline {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  line-height: var(--line-height-relaxed);
  margin-top: var(--spacing-2);
  padding-top: var(--spacing-2);
  border-top: 1px solid var(--border-light);
}

/* Byline */
.byline {
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-size: var(--font-size-sm);
  color: var(--text-primary);
}

/* Dateline */
.dateline {
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: var(--font-size-xs);
  color: var(--text-secondary);
  font-weight: 500;
}

/* Kicker / Section Label */
.kicker {
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: var(--font-size-xs);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--spacing-2);
}

/* Grid-based layout helpers */
.rule-left {
  border-left: 1px solid var(--border-default);
  padding-left: var(--spacing-6);
}

.rule-right {
  border-right: 1px solid var(--border-default);
  padding-right: var(--spacing-6);
}

.rule-top {
  border-top: 1px solid var(--text-primary);
  padding-top: var(--spacing-6);
}

.rule-bottom {
  border-bottom: 1px solid var(--text-primary);
  padding-bottom: var(--spacing-6);
}

/* =====================================================
   Horizon v2 Import (Paper Wrapper)
   ===================================================== */

.paper-toc-loading,
.paper-sidebar-loading {
  font-size: var(--font-size-sm);
  color: var(--text-muted);
  padding: var(--spacing-2) 0;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-2);
}

.paper-loading {
  border-style: dashed;
  border-color: var(--border-default);
  overflow: hidden;
}

.paper-loading .loading-line {
  margin: calc(var(--spacing-6) * -1) calc(var(--spacing-6) * -1) var(--spacing-4);
}

.paper-loading-body {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-3);
  text-align: center;
}

/* Paper-specific loading visuals */
.paper-main .loading-line {
  height: 2px;
  border-radius: 0;
  background: var(--border-default);
}

.paper-main .loading-line::after {
  background: var(--text-primary);
}

.paper-main .spinner {
  border-color: var(--border-default);
  border-top-color: var(--text-primary);
}