/**
 * Semantic CSS - Attribute-Based Styling Framework
 * A modern approach using semantic HTML elements and attribute selectors
 * No classes. No IDs. Just semantic elements and attributes.
 * 
 * Usage:
 *   <link rel="stylesheet" href="css/semantic.css">
 */

/* ==================================================
   1. Design Tokens (CSS Variables)
   ================================================== */

@font-face {
  font-family: 'GT Ultra Fine';
  src: url('../fonts/GT-Ultra-Fine-Light.woff2') format('woff2'),
       url('../fonts/GT-Ultra-Fine-Light.woff') format('woff'),
       url('../fonts/GT-Ultra-Fine-Light.ttf') format('truetype');
  font-weight: 300;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: 'GT Ultra Fine';
  src: url('../fonts/GT-Ultra-Fine-Bold.woff2') format('woff2'),
       url('../fonts/GT-Ultra-Fine-Bold.woff') format('woff'),
       url('../fonts/GT-Ultra-Fine-Bold.ttf') format('truetype');
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: 'GT Ultra Standard';
  src: url('../fonts/GT-Ultra-Standard-Light.woff2') format('woff2'),
       url('../fonts/GT-Ultra-Standard-Light.woff') format('woff'),
       url('../fonts/GT-Ultra-Standard-Light.ttf') format('truetype');
  font-weight: 300;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: 'GT Ultra Standard';
  src: url('../fonts/GT-Ultra-Standard-Bold.woff2') format('woff2'),
       url('../fonts/GT-Ultra-Standard-Bold.woff') format('woff'),
       url('../fonts/GT-Ultra-Standard-Bold.ttf') format('truetype');
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

:root {
  /* Color Palette */
  --primary: #4a90e2;
  --primary-rgb: 74, 144, 226;
  --primary-dark: #3a7bc8;
  --primary-light: rgba(74, 144, 226, 0.1);
  --secondary: #7ed321;
  --accent: #f5a623;
  --accent-rgb: 245, 166, 35;
  --danger: #d0021b;
  --success: #7ed321;
  --warning: #f5a623;

  /* Neutral Colors */
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;

  /* Semantic Colors */
  --text: var(--gray-900);
  --text-muted: var(--gray-500);
  --surface: #ffffff;
  --surface-elevated: #ffffff;
  --background: var(--gray-100);
  --border: var(--gray-200);
  --muted: var(--gray-500);

  /* Typography */
  --sans: 'GT Ultra Standard', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --serif: 'GT Ultra Fine', Georgia, serif;
  --mono: 'SF Mono', Monaco, 'Cascadia Code', 'Consolas', monospace;

  /* Font Sizes */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;

  /* Line Heights */
  --leading-tight: 1.25;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;

  /* Spacing Scale */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.2s ease;
  --transition-slow: 0.3s ease;

  /* Interactive sizing - iOS friendly */
  --min-tap-target: 48px;

  /* iOS Safe Area Insets */
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-right: env(safe-area-inset-right, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
  --safe-left: env(safe-area-inset-left, 0px);

  /* Container sizes */
  --container-sm: 40rem;
  --container-md: 48rem;
  --container-lg: 64rem;
  --container-xl: 80rem;
  --container-2xl: 96rem;
}

/* ==================================================
   2. Base Reset & Element Styles
   ================================================== */

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  height: 100%;
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--sans);
  font-size: var(--text-base);
  font-weight: 300;
  line-height: var(--leading-normal);
  color: var(--text);
  background-color: var(--background);
  min-height: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography - Just Works */
h1, h2, h3 {
  font-family: var(--serif);
  font-weight: 700;
  line-height: var(--leading-tight);
  color: var(--text);
  margin-top: var(--space-lg);
  margin-bottom: var(--space-md);
}

h4, h5, h6 {
  font-family: var(--sans);
  font-weight: 700;
  line-height: var(--leading-tight);
  color: var(--text);
  margin-top: var(--space-lg);
  margin-bottom: var(--space-md);
}

h1 { font-size: var(--text-4xl); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-2xl); }
h4 { font-size: var(--text-xl); }
h5 { font-size: var(--text-lg); }
h6 { font-size: var(--text-base); }

h1:first-child, h2:first-child, h3:first-child,
h4:first-child, h5:first-child, h6:first-child {
  margin-top: 0;
}

p {
  margin-top: 0;
  margin-bottom: var(--space-md);
}

p:last-child {
  margin-bottom: 0;
}

strong, b {
  font-weight: 700;
}

em, i {
  font-style: italic;
}

small {
  font-size: var(--text-sm);
  color: var(--muted);
}

mark {
  background-color: rgba(var(--accent-rgb), 0.3);
  padding: 0.125em 0.25em;
  border-radius: var(--radius-sm);
}

code {
  font-family: var(--mono);
  font-size: 0.9em;
  background-color: var(--gray-100);
  padding: 0.125em 0.375em;
  border-radius: var(--radius-sm);
}

pre {
  font-family: var(--mono);
  font-size: var(--text-sm);
  background-color: var(--gray-900);
  color: var(--gray-100);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin: var(--space-md) 0;
}

pre code {
  background: none;
  padding: 0;
  font-size: inherit;
  color: inherit;
}

blockquote {
  font-family: var(--serif);
  font-style: italic;
  color: var(--muted);
  border-left: 3px solid var(--primary);
  padding-left: var(--space-md);
  margin: var(--space-md) 0;
}

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

/* Lists */
ul, ol {
  padding-left: var(--space-xl);
  margin: var(--space-md) 0;
}

li {
  margin-bottom: var(--space-xs);
}

li:last-child {
  margin-bottom: 0;
}

/* Description lists */
dl {
  margin: var(--space-md) 0;
}

dt {
  font-weight: 700;
  margin-top: var(--space-sm);
}

dd {
  margin-left: var(--space-lg);
  color: var(--muted);
}

/* Links */
a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 700;
  transition: color var(--transition-fast);
}

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

a:focus-visible {
  outline: 3px solid rgba(var(--primary-rgb), 0.5);
  outline-offset: 2px;
}

/* Horizontal rule */
hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: var(--space-lg) 0;
}

/* Time element */
time {
  font-variant-numeric: tabular-nums;
}

/* Address */
address {
  font-style: normal;
}

/* Native interactive - details/summary */
details {
  margin: var(--space-md) 0;
}

summary {
  cursor: pointer;
  font-weight: 700;
  padding: var(--space-sm) var(--space-md);
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  list-style: none;
  display: flex;
  align-items: center;
  min-height: var(--min-tap-target);
  transition: background-color var(--transition-fast);
}

summary::-webkit-details-marker {
  display: none;
}

summary::before {
  content: '';
  display: inline-block;
  width: 0.5em;
  height: 0.5em;
  margin-right: var(--space-sm);
  border-right: 2px solid var(--primary);
  border-bottom: 2px solid var(--primary);
  transform: rotate(-45deg);
  transition: transform var(--transition-fast);
}

details[open] summary::before {
  transform: rotate(45deg);
}

summary:hover {
  background-color: var(--primary-light);
}

details > *:not(summary) {
  padding: var(--space-md);
}

/* Dialog */
dialog {
  border: none;
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-xl);
  max-width: min(90vw, 32rem);
}

dialog::backdrop {
  background-color: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
}

/* Output (for toasts) */
output {
  display: block;
}

/* ==================================================
   3. Document Structure Elements
   ================================================== */

header {
  background-color: var(--surface);
  box-shadow: var(--shadow-sm);
  position: relative;
  z-index: 100;
}

header[sticky] {
  position: sticky;
  top: 0;
}

footer {
  color: var(--muted);
}

main {
  width: 100%;
  max-width: var(--container-xl);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-md);
  padding-right: var(--space-md);
}

main[size="sm"] { max-width: var(--container-sm); }
main[size="md"] { max-width: var(--container-md); }
main[size="lg"] { max-width: var(--container-lg); }
main[size="xl"] { max-width: var(--container-xl); }
main[size="2xl"] { max-width: var(--container-2xl); }
main[size="full"] { max-width: 100%; }

nav {
  display: flex;
  align-items: center;
}

nav a {
  padding: var(--space-sm) var(--space-md);
  min-height: var(--min-tap-target);
  display: inline-flex;
  align-items: center;
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

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

nav a[aria-current="page"] {
  color: var(--primary);
  background-color: var(--primary-light);
}

aside {
  background-color: var(--surface);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
}

/* Section has no default styling - it's purely structural */
section {
  /* Intentionally minimal */
}

/* ==================================================
   4. Layout Attributes
   ================================================== */

/* Display / Layout type */
[layout="flex"] { display: flex; }
[layout="inline-flex"] { display: inline-flex; }
[layout="grid"] { display: grid; }
[layout="inline-grid"] { display: inline-grid; }
[layout="block"] { display: block; }
[layout="inline"] { display: inline; }
[layout="inline-block"] { display: inline-block; }

/* Common patterns */
[layout="stack"] {
  display: flex;
  flex-direction: column;
}

[layout="row"] {
  display: flex;
  flex-direction: row;
}

[layout="center"] {
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Flex direction */
[direction="row"] { flex-direction: row; }
[direction="row-reverse"] { flex-direction: row-reverse; }
[direction="col"] { flex-direction: column; }
[direction="col-reverse"] { flex-direction: column-reverse; }

/* Grid columns */
[cols="1"] { grid-template-columns: repeat(1, minmax(0, 1fr)); }
[cols="2"] { grid-template-columns: repeat(2, minmax(0, 1fr)); }
[cols="3"] { grid-template-columns: repeat(3, minmax(0, 1fr)); }
[cols="4"] { grid-template-columns: repeat(4, minmax(0, 1fr)); }
[cols="5"] { grid-template-columns: repeat(5, minmax(0, 1fr)); }
[cols="6"] { grid-template-columns: repeat(6, minmax(0, 1fr)); }
[cols="12"] { grid-template-columns: repeat(12, minmax(0, 1fr)); }
[cols="auto"] { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
[cols="auto-fill"] { grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }

/* Grid rows */
[rows="1"] { grid-template-rows: repeat(1, minmax(0, 1fr)); }
[rows="2"] { grid-template-rows: repeat(2, minmax(0, 1fr)); }
[rows="3"] { grid-template-rows: repeat(3, minmax(0, 1fr)); }

/* Column span */
[span="2"] { grid-column: span 2; }
[span="3"] { grid-column: span 3; }
[span="4"] { grid-column: span 4; }
[span="full"] { grid-column: 1 / -1; }

/* Align items (cross axis) */
[align="start"] { align-items: flex-start; }
[align="center"] { align-items: center; }
[align="end"] { align-items: flex-end; }
[align="stretch"] { align-items: stretch; }
[align="baseline"] { align-items: baseline; }

/* Justify content (main axis) */
[justify="start"] { justify-content: flex-start; }
[justify="center"] { justify-content: center; }
[justify="end"] { justify-content: flex-end; }
[justify="between"] { justify-content: space-between; }
[justify="around"] { justify-content: space-around; }
[justify="evenly"] { justify-content: space-evenly; }

/* Self alignment */
[self="start"] { align-self: flex-start; }
[self="center"] { align-self: center; }
[self="end"] { align-self: flex-end; }
[self="stretch"] { align-self: stretch; }

/* Gap */
[gap="0"] { gap: 0; }
[gap="xs"] { gap: var(--space-xs); }
[gap="sm"] { gap: var(--space-sm); }
[gap="md"] { gap: var(--space-md); }
[gap="lg"] { gap: var(--space-lg); }
[gap="xl"] { gap: var(--space-xl); }
[gap="2xl"] { gap: var(--space-2xl); }

/* Row gap */
[row-gap="xs"] { row-gap: var(--space-xs); }
[row-gap="sm"] { row-gap: var(--space-sm); }
[row-gap="md"] { row-gap: var(--space-md); }
[row-gap="lg"] { row-gap: var(--space-lg); }
[row-gap="xl"] { row-gap: var(--space-xl); }

/* Column gap */
[col-gap="xs"] { column-gap: var(--space-xs); }
[col-gap="sm"] { column-gap: var(--space-sm); }
[col-gap="md"] { column-gap: var(--space-md); }
[col-gap="lg"] { column-gap: var(--space-lg); }
[col-gap="xl"] { column-gap: var(--space-xl); }

/* Wrap */
[wrap] { flex-wrap: wrap; }
[nowrap] { flex-wrap: nowrap; }
[wrap-reverse] { flex-wrap: wrap-reverse; }

/* Flex grow/shrink */
[grow] { flex-grow: 1; }
[grow="0"] { flex-grow: 0; }
[shrink] { flex-shrink: 1; }
[shrink="0"] { flex-shrink: 0; }
[flex="1"] { flex: 1 1 0%; }
[flex="auto"] { flex: 1 1 auto; }
[flex="none"] { flex: none; }

/* Position */
[position="relative"] { position: relative; }
[position="absolute"] { position: absolute; }
[position="fixed"] { position: fixed; }
[position="sticky"] { position: sticky; }
[position="static"] { position: static; }

/* Inset */
[inset="0"] { inset: 0; }
[top="0"] { top: 0; }
[right="0"] { right: 0; }
[bottom="0"] { bottom: 0; }
[left="0"] { left: 0; }

/* Z-index */
[z="0"] { z-index: 0; }
[z="10"] { z-index: 10; }
[z="20"] { z-index: 20; }
[z="30"] { z-index: 30; }
[z="40"] { z-index: 40; }
[z="50"] { z-index: 50; }
[z="auto"] { z-index: auto; }

/* Width */
[w="full"] { width: 100%; }
[w="auto"] { width: auto; }
[w="screen"] { width: 100vw; }
[w="fit"] { width: fit-content; }
[w="min"] { width: min-content; }
[w="max"] { width: max-content; }

/* Height */
[h="full"] { height: 100%; }
[h="auto"] { height: auto; }
[h="screen"] { height: 100vh; }
[h="fit"] { height: fit-content; }
[h="min"] { height: min-content; }

/* Min/Max dimensions */
[min-h="screen"] { min-height: 100vh; }
[min-h="full"] { min-height: 100%; }
[max-w="full"] { max-width: 100%; }

/* Overflow */
[overflow="auto"] { overflow: auto; }
[overflow="hidden"] { overflow: hidden; }
[overflow="visible"] { overflow: visible; }
[overflow="scroll"] { overflow: scroll; }
[overflow-x="auto"] { overflow-x: auto; }
[overflow-y="auto"] { overflow-y: auto; }

/* ==================================================
   5. Spacing Attributes
   ================================================== */

/* Padding - All sides */
[p="0"] { padding: 0; }
[p="xs"] { padding: var(--space-xs); }
[p="sm"] { padding: var(--space-sm); }
[p="md"] { padding: var(--space-md); }
[p="lg"] { padding: var(--space-lg); }
[p="xl"] { padding: var(--space-xl); }
[p="2xl"] { padding: var(--space-2xl); }

/* Padding - Horizontal */
[px="0"] { padding-left: 0; padding-right: 0; }
[px="xs"] { padding-left: var(--space-xs); padding-right: var(--space-xs); }
[px="sm"] { padding-left: var(--space-sm); padding-right: var(--space-sm); }
[px="md"] { padding-left: var(--space-md); padding-right: var(--space-md); }
[px="lg"] { padding-left: var(--space-lg); padding-right: var(--space-lg); }
[px="xl"] { padding-left: var(--space-xl); padding-right: var(--space-xl); }
[px="2xl"] { padding-left: var(--space-2xl); padding-right: var(--space-2xl); }

/* Padding - Vertical */
[py="0"] { padding-top: 0; padding-bottom: 0; }
[py="xs"] { padding-top: var(--space-xs); padding-bottom: var(--space-xs); }
[py="sm"] { padding-top: var(--space-sm); padding-bottom: var(--space-sm); }
[py="md"] { padding-top: var(--space-md); padding-bottom: var(--space-md); }
[py="lg"] { padding-top: var(--space-lg); padding-bottom: var(--space-lg); }
[py="xl"] { padding-top: var(--space-xl); padding-bottom: var(--space-xl); }
[py="2xl"] { padding-top: var(--space-2xl); padding-bottom: var(--space-2xl); }

/* Padding - Individual sides */
[pt="0"] { padding-top: 0; }
[pt="xs"] { padding-top: var(--space-xs); }
[pt="sm"] { padding-top: var(--space-sm); }
[pt="md"] { padding-top: var(--space-md); }
[pt="lg"] { padding-top: var(--space-lg); }
[pt="xl"] { padding-top: var(--space-xl); }

[pr="0"] { padding-right: 0; }
[pr="xs"] { padding-right: var(--space-xs); }
[pr="sm"] { padding-right: var(--space-sm); }
[pr="md"] { padding-right: var(--space-md); }
[pr="lg"] { padding-right: var(--space-lg); }
[pr="xl"] { padding-right: var(--space-xl); }

[pb="0"] { padding-bottom: 0; }
[pb="xs"] { padding-bottom: var(--space-xs); }
[pb="sm"] { padding-bottom: var(--space-sm); }
[pb="md"] { padding-bottom: var(--space-md); }
[pb="lg"] { padding-bottom: var(--space-lg); }
[pb="xl"] { padding-bottom: var(--space-xl); }

[pl="0"] { padding-left: 0; }
[pl="xs"] { padding-left: var(--space-xs); }
[pl="sm"] { padding-left: var(--space-sm); }
[pl="md"] { padding-left: var(--space-md); }
[pl="lg"] { padding-left: var(--space-lg); }
[pl="xl"] { padding-left: var(--space-xl); }

/* Margin - All sides */
[m="0"] { margin: 0; }
[m="xs"] { margin: var(--space-xs); }
[m="sm"] { margin: var(--space-sm); }
[m="md"] { margin: var(--space-md); }
[m="lg"] { margin: var(--space-lg); }
[m="xl"] { margin: var(--space-xl); }
[m="2xl"] { margin: var(--space-2xl); }
[m="auto"] { margin: auto; }

/* Margin - Horizontal */
[mx="0"] { margin-left: 0; margin-right: 0; }
[mx="xs"] { margin-left: var(--space-xs); margin-right: var(--space-xs); }
[mx="sm"] { margin-left: var(--space-sm); margin-right: var(--space-sm); }
[mx="md"] { margin-left: var(--space-md); margin-right: var(--space-md); }
[mx="lg"] { margin-left: var(--space-lg); margin-right: var(--space-lg); }
[mx="xl"] { margin-left: var(--space-xl); margin-right: var(--space-xl); }
[mx="auto"] { margin-left: auto; margin-right: auto; }

/* Margin - Vertical */
[my="0"] { margin-top: 0; margin-bottom: 0; }
[my="xs"] { margin-top: var(--space-xs); margin-bottom: var(--space-xs); }
[my="sm"] { margin-top: var(--space-sm); margin-bottom: var(--space-sm); }
[my="md"] { margin-top: var(--space-md); margin-bottom: var(--space-md); }
[my="lg"] { margin-top: var(--space-lg); margin-bottom: var(--space-lg); }
[my="xl"] { margin-top: var(--space-xl); margin-bottom: var(--space-xl); }
[my="2xl"] { margin-top: var(--space-2xl); margin-bottom: var(--space-2xl); }
[my="auto"] { margin-top: auto; margin-bottom: auto; }

/* Margin - Individual sides */
[mt="0"] { margin-top: 0; }
[mt="xs"] { margin-top: var(--space-xs); }
[mt="sm"] { margin-top: var(--space-sm); }
[mt="md"] { margin-top: var(--space-md); }
[mt="lg"] { margin-top: var(--space-lg); }
[mt="xl"] { margin-top: var(--space-xl); }
[mt="2xl"] { margin-top: var(--space-2xl); }
[mt="auto"] { margin-top: auto; }

[mr="0"] { margin-right: 0; }
[mr="xs"] { margin-right: var(--space-xs); }
[mr="sm"] { margin-right: var(--space-sm); }
[mr="md"] { margin-right: var(--space-md); }
[mr="lg"] { margin-right: var(--space-lg); }
[mr="xl"] { margin-right: var(--space-xl); }
[mr="auto"] { margin-right: auto; }

[mb="0"] { margin-bottom: 0; }
[mb="xs"] { margin-bottom: var(--space-xs); }
[mb="sm"] { margin-bottom: var(--space-sm); }
[mb="md"] { margin-bottom: var(--space-md); }
[mb="lg"] { margin-bottom: var(--space-lg); }
[mb="xl"] { margin-bottom: var(--space-xl); }
[mb="2xl"] { margin-bottom: var(--space-2xl); }

[ml="0"] { margin-left: 0; }
[ml="xs"] { margin-left: var(--space-xs); }
[ml="sm"] { margin-left: var(--space-sm); }
[ml="md"] { margin-left: var(--space-md); }
[ml="lg"] { margin-left: var(--space-lg); }
[ml="xl"] { margin-left: var(--space-xl); }
[ml="auto"] { margin-left: auto; }

/* ==================================================
   6. Content Blocks (article, section, figure)
   ================================================== */

/* Article as card-like content block */
article {
  background-color: var(--surface);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  border: 1px solid var(--border);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

article[variant="outlined"] {
  background-color: transparent;
}

article[variant="elevated"] {
  box-shadow: var(--shadow-md);
  border: none;
}

article[variant="flat"] {
  border: none;
  background-color: transparent;
  padding: 0;
}

article[variant="ghost"] {
  background-color: transparent;
  border: none;
}

article[clickable] {
  cursor: pointer;
}

article[clickable]:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

article[clickable]:active {
  transform: translateY(0);
}

/* Figure for media with captions */
figure {
  margin: 0;
}

figure img,
figure video,
figure picture {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
}

figcaption {
  font-size: var(--text-sm);
  color: var(--muted);
  margin-top: var(--space-sm);
}

figcaption[align="center"] {
  text-align: center;
}

/* ==================================================
   7. Interactive Elements (Buttons, Forms)
   ================================================== */

/* Buttons */
button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  font-family: var(--sans);
  font-weight: 700;
  font-size: var(--text-base);
  padding: var(--space-sm) var(--space-md);
  min-height: var(--min-tap-target);
  border-radius: var(--radius-sm);
  border: none;
  background-color: var(--primary);
  color: white;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;
  position: relative;
}

button:hover {
  background-color: var(--primary-dark);
  transform: translateY(-1px);
}

button:active {
  transform: translateY(1px);
}

button:focus-visible {
  outline: 3px solid rgba(var(--primary-rgb), 0.5);
  outline-offset: 2px;
}

/* Button variants */
button[variant="secondary"] {
  background-color: transparent;
  border: 2px solid var(--primary);
  color: var(--primary);
}

button[variant="secondary"]:hover {
  background-color: var(--primary-light);
}

button[variant="danger"] {
  background-color: var(--danger);
}

button[variant="danger"]:hover {
  background-color: #b8011a;
}

button[variant="success"] {
  background-color: var(--success);
}

button[variant="ghost"] {
  background-color: transparent;
  color: var(--primary);
}

button[variant="ghost"]:hover {
  background-color: var(--primary-light);
}

button[variant="link"] {
  background: none;
  color: var(--primary);
  padding: 0;
  min-height: auto;
  font-weight: 700;
}

button[variant="link"]:hover {
  text-decoration: underline;
  transform: none;
}

/* Button sizes */
button[size="xs"] {
  padding: var(--space-xs) var(--space-sm);
  min-height: 32px;
  font-size: var(--text-xs);
}

button[size="sm"] {
  padding: var(--space-xs) var(--space-sm);
  min-height: 36px;
  font-size: var(--text-sm);
}

button[size="lg"] {
  padding: var(--space-md) var(--space-lg);
  min-height: 56px;
  font-size: var(--text-lg);
}

button[size="xl"] {
  padding: var(--space-md) var(--space-xl);
  min-height: 64px;
  font-size: var(--text-xl);
}

/* Button full width */
button[full] {
  width: 100%;
}

/* Button states */
button:disabled,
button[disabled] {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

button[loading] {
  pointer-events: none;
  color: transparent;
}

button[loading]::after {
  content: '';
  position: absolute;
  width: 1.2em;
  height: 1.2em;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: white;
  animation: spin 0.6s linear infinite;
}

button[variant="secondary"][loading]::after,
button[variant="ghost"][loading]::after {
  border-color: rgba(var(--primary-rgb), 0.3);
  border-top-color: var(--primary);
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Button with icon */
button[icon-only] {
  padding: var(--space-sm);
  aspect-ratio: 1;
}

/* Form Elements */
label {
  display: block;
  font-weight: 700;
  margin-bottom: var(--space-sm);
  color: var(--text);
}

label[inline] {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  font-weight: 400;
}

input,
select,
textarea {
  font-family: var(--sans);
  font-size: var(--text-base);
  font-weight: 300;
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background-color: var(--surface);
  color: var(--text);
  width: 100%;
  min-height: var(--min-tap-target);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

input:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(var(--primary-rgb), 0.25);
}

input::placeholder,
textarea::placeholder {
  color: var(--gray-400);
}

/* Validation states */
input:invalid:not(:placeholder-shown),
select:invalid:not(:placeholder-shown),
textarea:invalid:not(:placeholder-shown) {
  border-color: var(--danger);
}

input:invalid:not(:placeholder-shown):focus,
select:invalid:not(:placeholder-shown):focus,
textarea:invalid:not(:placeholder-shown):focus {
  box-shadow: 0 0 0 3px rgba(208, 2, 27, 0.25);
}

input:valid:not(:placeholder-shown),
select:valid:not(:placeholder-shown),
textarea:valid:not(:placeholder-shown) {
  border-color: var(--success);
}

/* Select styling */
select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' width='24' height='24'%3E%3Cpath fill='%236b7280' d='M7 10l5 5 5-5z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--space-sm) center;
  padding-right: 2.5rem;
}

/* Textarea */
textarea {
  min-height: 120px;
  resize: vertical;
}

textarea[resize="none"] { resize: none; }
textarea[resize="horizontal"] { resize: horizontal; }
textarea[resize="both"] { resize: both; }

/* Checkbox and Radio - enhanced native */
input[type="checkbox"],
input[type="radio"] {
  width: 1.25rem;
  height: 1.25rem;
  min-height: auto;
  margin: 0;
  accent-color: var(--primary);
  cursor: pointer;
}

/* Range input */
input[type="range"] {
  padding: 0;
  min-height: auto;
  accent-color: var(--primary);
}

/* Color input */
input[type="color"] {
  padding: var(--space-xs);
  min-height: var(--min-tap-target);
  width: var(--min-tap-target);
  cursor: pointer;
}

/* File input */
input[type="file"] {
  padding: var(--space-sm);
}

input[type="file"]::file-selector-button {
  font-family: var(--sans);
  font-weight: 700;
  padding: var(--space-xs) var(--space-sm);
  margin-right: var(--space-sm);
  border: none;
  border-radius: var(--radius-sm);
  background-color: var(--primary);
  color: white;
  cursor: pointer;
}

/* Form layout */
form[layout="stack"] {
  display: flex;
  flex-direction: column;
}

form[layout="stack"] > * + * {
  margin-top: var(--space-md);
}

form[layout="inline"] {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  align-items: flex-end;
}

/* Fieldset */
fieldset {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  margin: 0;
}

legend {
  font-weight: 700;
  padding: 0 var(--space-sm);
}

/* ==================================================
   8. Visual Utilities
   ================================================== */

/* Border radius */
[rounded] { border-radius: var(--radius-md); }
[rounded="none"] { border-radius: 0; }
[rounded="sm"] { border-radius: var(--radius-sm); }
[rounded="lg"] { border-radius: var(--radius-lg); }
[rounded="xl"] { border-radius: var(--radius-xl); }
[rounded="full"] { border-radius: var(--radius-full); }

/* Borders */
[border] { border: 1px solid var(--border); }
[border="none"] { border: none; }
[border="top"] { border-top: 1px solid var(--border); }
[border="right"] { border-right: 1px solid var(--border); }
[border="bottom"] { border-bottom: 1px solid var(--border); }
[border="left"] { border-left: 1px solid var(--border); }

[border-2] { border-width: 2px; }
[border-4] { border-width: 4px; }

[border-color="primary"] { border-color: var(--primary); }
[border-color="danger"] { border-color: var(--danger); }
[border-color="success"] { border-color: var(--success); }

/* Shadows */
[shadow] { box-shadow: var(--shadow-sm); }
[shadow="none"] { box-shadow: none; }
[shadow="md"] { box-shadow: var(--shadow-md); }
[shadow="lg"] { box-shadow: var(--shadow-lg); }
[shadow="xl"] { box-shadow: var(--shadow-xl); }

/* Text alignment */
[text="left"] { text-align: left; }
[text="center"] { text-align: center; }
[text="right"] { text-align: right; }
[text="justify"] { text-align: justify; }

/* Font family */
[font="sans"] { font-family: var(--sans); }
[font="serif"] { font-family: var(--serif); }
[font="mono"] { font-family: var(--mono); }

/* Font weight */
[weight="light"] { font-weight: 300; }
[weight="normal"] { font-weight: 400; }
[weight="medium"] { font-weight: 500; }
[weight="semibold"] { font-weight: 600; }
[weight="bold"] { font-weight: 700; }

/* Font size */
[size="xs"] { font-size: var(--text-xs); }
[size="sm"] { font-size: var(--text-sm); }
[size="base"] { font-size: var(--text-base); }
[size="lg"] { font-size: var(--text-lg); }
[size="xl"] { font-size: var(--text-xl); }
[size="2xl"] { font-size: var(--text-2xl); }
[size="3xl"] { font-size: var(--text-3xl); }
[size="4xl"] { font-size: var(--text-4xl); }

/* Line height */
[leading="tight"] { line-height: var(--leading-tight); }
[leading="normal"] { line-height: var(--leading-normal); }
[leading="relaxed"] { line-height: var(--leading-relaxed); }

/* Text colors */
[color="muted"] { color: var(--muted); }
[color="primary"] { color: var(--primary); }
[color="danger"] { color: var(--danger); }
[color="success"] { color: var(--success); }
[color="warning"] { color: var(--warning); }
[color="inherit"] { color: inherit; }

/* Background colors */
[bg="surface"] { background-color: var(--surface); }
[bg="background"] { background-color: var(--background); }
[bg="primary"] { background-color: var(--primary); color: white; }
[bg="primary-light"] { background-color: var(--primary-light); }
[bg="danger"] { background-color: var(--danger); color: white; }
[bg="success"] { background-color: var(--success); color: white; }
[bg="warning"] { background-color: var(--warning); }
[bg="transparent"] { background-color: transparent; }

/* Text decoration */
[underline] { text-decoration: underline; }
[line-through] { text-decoration: line-through; }
[no-underline] { text-decoration: none; }

/* Text transform */
[uppercase] { text-transform: uppercase; }
[lowercase] { text-transform: lowercase; }
[capitalize] { text-transform: capitalize; }
[normal-case] { text-transform: none; }

/* Truncate */
[truncate] {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

[line-clamp="2"] {
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

[line-clamp="3"] {
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Opacity */
[opacity="0"] { opacity: 0; }
[opacity="25"] { opacity: 0.25; }
[opacity="50"] { opacity: 0.5; }
[opacity="75"] { opacity: 0.75; }
[opacity="100"] { opacity: 1; }

/* Cursor */
[cursor="pointer"] { cursor: pointer; }
[cursor="default"] { cursor: default; }
[cursor="not-allowed"] { cursor: not-allowed; }
[cursor="grab"] { cursor: grab; }

/* Pointer events */
[pointer-events="none"] { pointer-events: none; }
[pointer-events="auto"] { pointer-events: auto; }

/* User select */
[select="none"] { user-select: none; -webkit-user-select: none; }
[select="text"] { user-select: text; }
[select="all"] { user-select: all; }

/* ==================================================
   9. State and Visibility
   ================================================== */

/* Native hidden attribute */
[hidden] {
  display: none !important;
}

/* Visibility */
[invisible] {
  visibility: hidden;
}

/* Screen reader only */
[sr-only] {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Loading state */
[loading] {
  position: relative;
  pointer-events: none;
}

/* Disabled state (for non-form elements) */
[disabled] {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* Responsive visibility */
@media (max-width: 640px) {
  [hide="sm"] { display: none !important; }
}

@media (max-width: 768px) {
  [hide="mobile"] { display: none !important; }
}

@media (min-width: 769px) {
  [hide="desktop"] { display: none !important; }
  [show="mobile"] { display: none !important; }
}

@media (min-width: 769px) and (max-width: 1024px) {
  [hide="tablet"] { display: none !important; }
}

@media (min-width: 1025px) {
  [hide="lg"] { display: none !important; }
}

/* Print visibility */
@media print {
  [hide="print"] { display: none !important; }
  [show="print"] { display: block !important; }
}

/* ==================================================
   10. Theme System (Dark Mode, Accessibility)
   ================================================== */

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

:focus-visible {
  outline: 3px solid rgba(var(--primary-rgb), 0.5);
  outline-offset: 2px;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* High contrast mode */
@media (prefers-contrast: high) {
  :root {
    --primary: #0066cc;
    --primary-dark: #004d99;
    --border: #000000;
    --muted: #333333;
  }

  a, button {
    text-decoration: underline;
  }
}

/* Dark mode via attribute */
[theme="dark"],
[data-theme="dark"] {
  --text: #f1f5f9;
  --text-muted: #94a3b8;
  --surface: #1e293b;
  --surface-elevated: #334155;
  --background: #0f172a;
  --border: #334155;
  --muted: #94a3b8;
  
  --gray-50: #0f172a;
  --gray-100: #1e293b;
  --gray-200: #334155;
  --gray-300: #475569;
  --gray-400: #64748b;
  --gray-500: #94a3b8;
  --gray-600: #cbd5e1;
  --gray-700: #e2e8f0;
  --gray-800: #f1f5f9;
  --gray-900: #f8fafc;

  --primary-light: rgba(74, 144, 226, 0.2);
}

[theme="dark"] code,
[data-theme="dark"] code {
  background-color: var(--gray-200);
}

[theme="dark"] pre,
[data-theme="dark"] pre {
  background-color: var(--gray-100);
}

/* System preference dark mode (when not explicitly set) */
@media (prefers-color-scheme: dark) {
  :root:not([theme="light"]):not([data-theme="light"]) {
    --text: #f1f5f9;
    --text-muted: #94a3b8;
    --surface: #1e293b;
    --surface-elevated: #334155;
    --background: #0f172a;
    --border: #334155;
    --muted: #94a3b8;
    
    --gray-50: #0f172a;
    --gray-100: #1e293b;
    --gray-200: #334155;
    --gray-300: #475569;
    --gray-400: #64748b;
    --gray-500: #94a3b8;
    --gray-600: #cbd5e1;
    --gray-700: #e2e8f0;
    --gray-800: #f1f5f9;
    --gray-900: #f8fafc;

    --primary-light: rgba(74, 144, 226, 0.2);
  }

  :root:not([theme="light"]):not([data-theme="light"]) code {
    background-color: var(--gray-200);
  }
}

/* iOS specific */
body[ios] {
  -webkit-overflow-scrolling: touch;
}

body[standalone] {
  padding-top: var(--safe-top);
  padding-bottom: var(--safe-bottom);
}

/* Safe area utilities */
[safe-top] { padding-top: var(--safe-top); }
[safe-bottom] { padding-bottom: var(--safe-bottom); }
[safe-left] { padding-left: var(--safe-left); }
[safe-right] { padding-right: var(--safe-right); }
[safe-x] { padding-left: var(--safe-left); padding-right: var(--safe-right); }
[safe-y] { padding-top: var(--safe-top); padding-bottom: var(--safe-bottom); }
[safe-all] {
  padding-top: var(--safe-top);
  padding-right: var(--safe-right);
  padding-bottom: var(--safe-bottom);
  padding-left: var(--safe-left);
}

/* ==================================================
   11. Toast Notifications (using output element)
   ================================================== */

output[role="status"] {
  position: fixed;
  bottom: calc(var(--space-md) + var(--safe-bottom));
  left: 50%;
  transform: translateX(-50%) translateY(100%);
  max-width: calc(100% - var(--space-xl));
  background-color: var(--gray-900);
  color: white;
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-lg);
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  z-index: 9999;
  opacity: 0;
  transition: transform var(--transition-slow), opacity var(--transition-slow);
  pointer-events: none;
}

output[role="status"][visible] {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
  pointer-events: auto;
}

output[role="status"][type="success"] { background-color: var(--success); }
output[role="status"][type="danger"] { background-color: var(--danger); }
output[role="status"][type="warning"] { background-color: var(--warning); color: var(--gray-900); }
output[role="status"][type="info"] { background-color: var(--primary); }

/* Toast container */
[role="log"] {
  position: fixed;
  bottom: var(--space-md);
  left: 0;
  right: 0;
  display: flex;
  flex-direction: column-reverse;
  align-items: center;
  gap: var(--space-sm);
  z-index: 9999;
  pointer-events: none;
  padding-bottom: var(--safe-bottom);
}

[role="log"] output[role="status"] {
  position: relative;
  bottom: auto;
  left: auto;
  transform: translateY(100%);
  opacity: 0;
}

[role="log"] output[role="status"][visible] {
  transform: translateY(0);
  opacity: 1;
}

/* ==================================================
   12. Responsive Adjustments
   ================================================== */

@media (max-width: 640px) {
  :root {
    --space-lg: 1.25rem;
    --space-xl: 1.5rem;
    --space-2xl: 2rem;
  }

  main {
    padding-left: var(--space-sm);
    padding-right: var(--space-sm);
  }

  button[full-mobile] {
    width: 100%;
  }

  /* Stack on mobile */
  [stack-mobile] {
    flex-direction: column;
  }

  [stack-mobile] > * {
    width: 100%;
  }

  /* Single column on mobile */
  [cols][responsive] {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 641px) and (max-width: 1024px) {
  /* Tablet adjustments */
  [cols="4"][responsive] { grid-template-columns: repeat(2, 1fr); }
  [cols="5"][responsive] { grid-template-columns: repeat(2, 1fr); }
  [cols="6"][responsive] { grid-template-columns: repeat(3, 1fr); }
}

/* ==================================================
   13. Alerts
   ================================================== */

aside[role="alert"] {
  display: flex;
  align-items: flex-start;
  gap: var(--space-md);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  border-left: 4px solid var(--primary);
  background-color: var(--primary-light);
  margin: var(--space-md) 0;
}

aside[role="alert"] > *:first-child:not(button[close]) {
  flex: 1;
}

aside[role="alert"][type="info"] {
  border-color: var(--primary);
  background-color: rgba(var(--primary-rgb), 0.1);
}

aside[role="alert"][type="success"] {
  border-color: var(--success);
  background-color: rgba(126, 211, 33, 0.1);
}

aside[role="alert"][type="warning"] {
  border-color: var(--warning);
  background-color: rgba(245, 166, 35, 0.15);
}

aside[role="alert"][type="danger"] {
  border-color: var(--danger);
  background-color: rgba(208, 2, 27, 0.1);
}

aside[role="alert"] strong {
  display: block;
  margin-bottom: var(--space-xs);
}

aside[role="alert"] p {
  margin: 0;
}

aside[role="alert"] p + p {
  margin-top: var(--space-sm);
}

/* ==================================================
   14. Badges
   ================================================== */

data[variant],
output[variant] {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.25em 0.5em;
  font-size: var(--text-xs);
  font-weight: 700;
  line-height: 1;
  border-radius: var(--radius-sm);
  min-width: 1.5em;
  text-align: center;
  vertical-align: middle;
  white-space: nowrap;
}

data[variant="primary"],
output[variant="primary"] {
  background-color: var(--primary);
  color: white;
}

data[variant="secondary"],
output[variant="secondary"] {
  background-color: var(--gray-500);
  color: white;
}

data[variant="success"],
output[variant="success"] {
  background-color: var(--success);
  color: white;
}

data[variant="danger"],
output[variant="danger"] {
  background-color: var(--danger);
  color: white;
}

data[variant="warning"],
output[variant="warning"] {
  background-color: var(--warning);
  color: var(--gray-900);
}

data[variant="info"],
output[variant="info"] {
  background-color: var(--primary);
  color: white;
}

data[variant="light"],
output[variant="light"] {
  background-color: var(--gray-200);
  color: var(--gray-800);
}

data[variant="dark"],
output[variant="dark"] {
  background-color: var(--gray-800);
  color: white;
}

data[pill],
output[pill] {
  border-radius: var(--radius-full);
  padding: 0.25em 0.75em;
}

data[size="lg"],
output[size="lg"] {
  font-size: var(--text-sm);
  padding: 0.35em 0.65em;
}

/* ==================================================
   15. Breadcrumbs & Pagination
   ================================================== */

/* Breadcrumbs */
nav[aria-label="Breadcrumb"] ol,
nav[aria-label="breadcrumb"] ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  list-style: none;
  padding: 0;
  margin: 0;
  gap: var(--space-xs);
}

nav[aria-label="Breadcrumb"] li,
nav[aria-label="breadcrumb"] li {
  display: flex;
  align-items: center;
  margin: 0;
}

nav[aria-label="Breadcrumb"] li + li::before,
nav[aria-label="breadcrumb"] li + li::before {
  content: "/";
  padding-right: var(--space-xs);
  color: var(--muted);
}

nav[aria-label="Breadcrumb"] a,
nav[aria-label="breadcrumb"] a {
  color: var(--muted);
  font-weight: 400;
}

nav[aria-label="Breadcrumb"] a:hover,
nav[aria-label="breadcrumb"] a:hover {
  color: var(--primary);
}

nav[aria-label="Breadcrumb"] [aria-current="page"],
nav[aria-label="breadcrumb"] [aria-current="page"] {
  color: var(--text);
  font-weight: 700;
}

/* Pagination */
nav[aria-label="Pagination"] ol,
nav[aria-label="pagination"] ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  list-style: none;
  padding: 0;
  margin: 0;
  gap: var(--space-xs);
}

nav[aria-label="Pagination"] li,
nav[aria-label="pagination"] li {
  margin: 0;
}

nav[aria-label="Pagination"] a,
nav[aria-label="Pagination"] button,
nav[aria-label="pagination"] a,
nav[aria-label="pagination"] button {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: var(--min-tap-target);
  min-height: var(--min-tap-target);
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background-color: var(--surface);
  color: var(--text);
  font-weight: 500;
  text-decoration: none;
  transition: all var(--transition-fast);
}

nav[aria-label="Pagination"] a:hover,
nav[aria-label="Pagination"] button:hover,
nav[aria-label="pagination"] a:hover,
nav[aria-label="pagination"] button:hover {
  background-color: var(--gray-100);
  border-color: var(--gray-300);
}

nav[aria-label="Pagination"] [aria-current="page"],
nav[aria-label="pagination"] [aria-current="page"] {
  background-color: var(--primary);
  border-color: var(--primary);
  color: white;
}

nav[aria-label="Pagination"] [disabled],
nav[aria-label="pagination"] [disabled] {
  opacity: 0.5;
  pointer-events: none;
}

/* ==================================================
   16. Button Groups
   ================================================== */

nav[role="group"] {
  display: inline-flex;
  border-radius: var(--radius-sm);
  overflow: hidden;
}

nav[role="group"] button,
nav[role="group"] a {
  border-radius: 0;
  margin: 0;
}

nav[role="group"] button + button,
nav[role="group"] a + a,
nav[role="group"] button + a,
nav[role="group"] a + button {
  margin-left: -1px;
}

nav[role="group"] > *:first-child {
  border-top-left-radius: var(--radius-sm);
  border-bottom-left-radius: var(--radius-sm);
}

nav[role="group"] > *:last-child {
  border-top-right-radius: var(--radius-sm);
  border-bottom-right-radius: var(--radius-sm);
}

nav[role="group"][vertical] {
  flex-direction: column;
}

nav[role="group"][vertical] button + button,
nav[role="group"][vertical] a + a {
  margin-left: 0;
  margin-top: -1px;
}

nav[role="group"][vertical] > *:first-child {
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
}

nav[role="group"][vertical] > *:last-child {
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
}

/* ==================================================
   17. List Groups
   ================================================== */

menu[role="listbox"],
ul[role="listbox"],
menu[role="list"],
ul[role="list"] {
  list-style: none;
  padding: 0;
  margin: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--surface);
}

menu[role="listbox"] > li,
ul[role="listbox"] > li,
menu[role="list"] > li,
ul[role="list"] > li {
  padding: var(--space-md);
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-md);
  margin: 0;
}

menu[role="listbox"] > li:last-child,
ul[role="listbox"] > li:last-child,
menu[role="list"] > li:last-child,
ul[role="list"] > li:last-child {
  border-bottom: none;
}

menu[role="listbox"] > li[aria-selected="true"],
ul[role="listbox"] > li[aria-selected="true"] {
  background-color: var(--primary-light);
  color: var(--primary);
}

menu[role="listbox"] > li[active],
ul[role="listbox"] > li[active],
menu[role="list"] > li[active],
ul[role="list"] > li[active] {
  background-color: var(--primary);
  color: white;
}

menu[role="listbox"] > li[disabled],
ul[role="listbox"] > li[disabled],
menu[role="list"] > li[disabled],
ul[role="list"] > li[disabled] {
  opacity: 0.5;
  pointer-events: none;
}

/* Clickable list items */
menu[role="listbox"] > li[clickable],
ul[role="listbox"] > li[clickable],
menu[role="list"] > li[clickable],
ul[role="list"] > li[clickable] {
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

menu[role="listbox"] > li[clickable]:hover,
ul[role="listbox"] > li[clickable]:hover,
menu[role="list"] > li[clickable]:hover,
ul[role="list"] > li[clickable]:hover {
  background-color: var(--gray-100);
}

/* Flush variant (no outer border) */
menu[role="listbox"][flush],
ul[role="listbox"][flush],
menu[role="list"][flush],
ul[role="list"][flush] {
  border: none;
  border-radius: 0;
}

/* ==================================================
   18. Progress & Meter
   ================================================== */

progress {
  width: 100%;
  height: 0.75rem;
  border-radius: var(--radius-full);
  overflow: hidden;
  appearance: none;
  -webkit-appearance: none;
  border: none;
  background-color: var(--gray-200);
}

progress::-webkit-progress-bar {
  background-color: var(--gray-200);
  border-radius: var(--radius-full);
}

progress::-webkit-progress-value {
  background-color: var(--primary);
  border-radius: var(--radius-full);
  transition: width var(--transition-normal);
}

progress::-moz-progress-bar {
  background-color: var(--primary);
  border-radius: var(--radius-full);
}

progress[variant="success"]::-webkit-progress-value,
progress[variant="success"]::-moz-progress-bar {
  background-color: var(--success);
}

progress[variant="warning"]::-webkit-progress-value,
progress[variant="warning"]::-moz-progress-bar {
  background-color: var(--warning);
}

progress[variant="danger"]::-webkit-progress-value,
progress[variant="danger"]::-moz-progress-bar {
  background-color: var(--danger);
}

progress[size="sm"] {
  height: 0.5rem;
}

progress[size="lg"] {
  height: 1.25rem;
}

/* Meter element */
meter {
  width: 100%;
  height: 0.75rem;
  border-radius: var(--radius-full);
  overflow: hidden;
  appearance: none;
  -webkit-appearance: none;
  border: none;
  background-color: var(--gray-200);
}

meter::-webkit-meter-bar {
  background-color: var(--gray-200);
  border-radius: var(--radius-full);
  border: none;
}

meter::-webkit-meter-optimum-value {
  background-color: var(--success);
  border-radius: var(--radius-full);
}

meter::-webkit-meter-suboptimum-value {
  background-color: var(--warning);
  border-radius: var(--radius-full);
}

meter::-webkit-meter-even-less-good-value {
  background-color: var(--danger);
  border-radius: var(--radius-full);
}

meter::-moz-meter-bar {
  border-radius: var(--radius-full);
}

/* ==================================================
   19. Typography Additions
   ================================================== */

/* Display headings */
h1[display], h2[display], h3[display], h4[display], h5[display], h6[display] {
  font-weight: 300;
  line-height: 1.1;
}

h1[display], [display="1"] {
  font-size: clamp(2.5rem, 5vw, 5rem);
}

[display="2"] {
  font-size: clamp(2.25rem, 4.5vw, 4.5rem);
}

[display="3"] {
  font-size: clamp(2rem, 4vw, 4rem);
}

[display="4"] {
  font-size: clamp(1.75rem, 3.5vw, 3.5rem);
}

[display="5"] {
  font-size: clamp(1.5rem, 3vw, 3rem);
}

[display="6"] {
  font-size: clamp(1.25rem, 2.5vw, 2.5rem);
}

/* Lead paragraph */
p[lead] {
  font-size: var(--text-xl);
  font-weight: 300;
  line-height: var(--leading-relaxed);
  color: var(--muted);
}

/* Text highlight */
[highlight] {
  background: linear-gradient(120deg, rgba(var(--accent-rgb), 0.3) 0%, rgba(var(--accent-rgb), 0.3) 100%);
  background-repeat: no-repeat;
  background-size: 100% 40%;
  background-position: 0 90%;
}

/* ==================================================
   20. Enhanced Forms
   ================================================== */

/* Input Groups */
label[layout="input-group"] {
  display: flex;
  align-items: stretch;
}

label[layout="input-group"] > span {
  display: flex;
  align-items: center;
  padding: var(--space-sm) var(--space-md);
  background-color: var(--gray-100);
  border: 1px solid var(--border);
  font-size: var(--text-sm);
  white-space: nowrap;
}

label[layout="input-group"] > input,
label[layout="input-group"] > select {
  flex: 1;
  min-width: 0;
  border-radius: 0;
}

label[layout="input-group"] > *:first-child {
  border-top-left-radius: var(--radius-sm);
  border-bottom-left-radius: var(--radius-sm);
}

label[layout="input-group"] > *:last-child {
  border-top-right-radius: var(--radius-sm);
  border-bottom-right-radius: var(--radius-sm);
}

label[layout="input-group"] > span + input,
label[layout="input-group"] > span + select,
label[layout="input-group"] > input + span,
label[layout="input-group"] > select + span,
label[layout="input-group"] > input + button,
label[layout="input-group"] > select + button {
  margin-left: -1px;
}

label[layout="input-group"] > button {
  border-radius: 0;
}

label[layout="input-group"] > button:last-child {
  border-top-right-radius: var(--radius-sm);
  border-bottom-right-radius: var(--radius-sm);
}

/* Floating Labels */
label[floating] {
  position: relative;
  display: block;
}

label[floating] > input,
label[floating] > textarea,
label[floating] > select {
  padding-top: 1.5rem;
  padding-bottom: 0.5rem;
}

label[floating] > span {
  position: absolute;
  top: 50%;
  left: var(--space-md);
  transform: translateY(-50%);
  color: var(--muted);
  font-weight: 400;
  pointer-events: none;
  transition: all var(--transition-fast);
  transform-origin: left top;
}

label[floating] > textarea + span {
  top: 1.5rem;
}

label[floating] > input:focus + span,
label[floating] > input:not(:placeholder-shown) + span,
label[floating] > textarea:focus + span,
label[floating] > textarea:not(:placeholder-shown) + span,
label[floating] > select:focus + span,
label[floating] > select:valid + span {
  top: 0.75rem;
  transform: translateY(0) scale(0.75);
  color: var(--primary);
  font-weight: 700;
}

/* Styled Checkbox */
input[type="checkbox"][styled] {
  appearance: none;
  -webkit-appearance: none;
  width: 1.25rem;
  height: 1.25rem;
  min-height: auto;
  border: 2px solid var(--gray-400);
  border-radius: var(--radius-sm);
  background-color: var(--surface);
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
}

input[type="checkbox"][styled]:hover {
  border-color: var(--primary);
}

input[type="checkbox"][styled]:checked {
  background-color: var(--primary);
  border-color: var(--primary);
}

input[type="checkbox"][styled]:checked::after {
  content: '';
  position: absolute;
  top: 1px;
  left: 5px;
  width: 5px;
  height: 10px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

input[type="checkbox"][styled]:focus-visible {
  outline: 3px solid rgba(var(--primary-rgb), 0.5);
  outline-offset: 2px;
}

/* Styled Radio */
input[type="radio"][styled] {
  appearance: none;
  -webkit-appearance: none;
  width: 1.25rem;
  height: 1.25rem;
  min-height: auto;
  border: 2px solid var(--gray-400);
  border-radius: 50%;
  background-color: var(--surface);
  cursor: pointer;
  transition: all var(--transition-fast);
}

input[type="radio"][styled]:hover {
  border-color: var(--primary);
}

input[type="radio"][styled]:checked {
  border-color: var(--primary);
  background-color: var(--primary);
  box-shadow: inset 0 0 0 3px var(--surface);
}

input[type="radio"][styled]:focus-visible {
  outline: 3px solid rgba(var(--primary-rgb), 0.5);
  outline-offset: 2px;
}

/* Switch Toggle */
input[type="checkbox"][switch] {
  appearance: none;
  -webkit-appearance: none;
  width: 2.75rem;
  height: 1.5rem;
  min-height: auto;
  border: none;
  border-radius: var(--radius-full);
  background-color: var(--gray-300);
  cursor: pointer;
  transition: background-color var(--transition-fast);
  position: relative;
}

input[type="checkbox"][switch]::before {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  width: calc(1.5rem - 4px);
  height: calc(1.5rem - 4px);
  border-radius: 50%;
  background-color: white;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-fast);
}

input[type="checkbox"][switch]:checked {
  background-color: var(--primary);
}

input[type="checkbox"][switch]:checked::before {
  transform: translateX(1.25rem);
}

input[type="checkbox"][switch]:focus-visible {
  outline: 3px solid rgba(var(--primary-rgb), 0.5);
  outline-offset: 2px;
}

/* ==================================================
   21. Tabs
   ================================================== */

[role="tablist"] {
  display: flex;
  border-bottom: 2px solid var(--border);
  gap: var(--space-xs);
  margin-bottom: var(--space-md);
}

[role="tablist"][vertical] {
  flex-direction: column;
  border-bottom: none;
  border-right: 2px solid var(--border);
  padding-right: var(--space-md);
}

[role="tab"] {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-sm) var(--space-md);
  min-height: var(--min-tap-target);
  border: none;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  background: none;
  color: var(--muted);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

[role="tab"]:hover {
  color: var(--text);
  border-bottom-color: var(--gray-300);
}

[role="tab"][aria-selected="true"] {
  color: var(--primary);
  border-bottom-color: var(--primary);
  font-weight: 700;
}

[role="tablist"][vertical] [role="tab"] {
  border-bottom: none;
  border-right: 2px solid transparent;
  margin-bottom: 0;
  margin-right: -2px;
  justify-content: flex-start;
}

[role="tablist"][vertical] [role="tab"]:hover {
  border-right-color: var(--gray-300);
}

[role="tablist"][vertical] [role="tab"][aria-selected="true"] {
  border-right-color: var(--primary);
}

[role="tabpanel"] {
  padding: var(--space-md) 0;
}

[role="tabpanel"][hidden] {
  display: none;
}

/* Pills variant */
[role="tablist"][variant="pills"] {
  border-bottom: none;
  gap: var(--space-sm);
}

[role="tablist"][variant="pills"] [role="tab"] {
  border: none;
  border-radius: var(--radius-full);
  margin-bottom: 0;
  padding: var(--space-sm) var(--space-lg);
}

[role="tablist"][variant="pills"] [role="tab"]:hover {
  background-color: var(--gray-100);
}

[role="tablist"][variant="pills"] [role="tab"][aria-selected="true"] {
  background-color: var(--primary);
  color: white;
}

/* ==================================================
   22. Offcanvas
   ================================================== */

dialog[position] {
  margin: 0;
  max-width: none;
  max-height: none;
  border: none;
  padding: var(--space-lg);
  box-shadow: var(--shadow-xl);
}

dialog[position="left"] {
  position: fixed;
  top: 0;
  left: 0;
  height: 100vh;
  width: min(80vw, 320px);
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
  transform: translateX(-100%);
  transition: transform var(--transition-slow);
}

dialog[position="left"][open] {
  transform: translateX(0);
}

dialog[position="right"] {
  position: fixed;
  top: 0;
  right: 0;
  height: 100vh;
  width: min(80vw, 320px);
  border-radius: var(--radius-lg) 0 0 var(--radius-lg);
  transform: translateX(100%);
  transition: transform var(--transition-slow);
}

dialog[position="right"][open] {
  transform: translateX(0);
}

dialog[position="top"] {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  width: 100%;
  max-height: 50vh;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  transform: translateY(-100%);
  transition: transform var(--transition-slow);
}

dialog[position="top"][open] {
  transform: translateY(0);
}

dialog[position="bottom"] {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  width: 100%;
  max-height: 50vh;
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  transform: translateY(100%);
  transition: transform var(--transition-slow);
}

dialog[position="bottom"][open] {
  transform: translateY(0);
}

/* ==================================================
   23. Responsive Navbar
   ================================================== */

nav[data-navbar] {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
}

[data-navbar-toggle] {
  display: none;
}

[data-navbar-menu] {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

@media (max-width: 768px) {
  [data-navbar-toggle] {
    display: inline-flex;
  }
  
  [data-navbar-menu] {
    display: none;
    width: 100%;
    flex-direction: column;
    align-items: stretch;
    padding-top: var(--space-md);
    border-top: 1px solid var(--border);
    margin-top: var(--space-md);
  }
  
  [data-navbar-menu][open],
  [data-navbar-menu]:not([hidden]) {
    display: flex;
  }
  
  [data-navbar-menu] a,
  [data-navbar-menu] button {
    width: 100%;
    justify-content: flex-start;
  }
}

/* ==================================================
   24. Close Button
   ================================================== */

button[close] {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  width: 2rem;
  height: 2rem;
  min-height: auto;
  font-size: 1.5rem;
  line-height: 1;
  background: transparent;
  border: none;
  color: var(--muted);
  cursor: pointer;
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

button[close]:hover {
  background-color: var(--gray-200);
  color: var(--text);
}

button[close][variant="light"] {
  color: rgba(255, 255, 255, 0.7);
}

button[close][variant="light"]:hover {
  background-color: rgba(255, 255, 255, 0.2);
  color: white;
}

/* ==================================================
   25. Dropdown (Details/Menu)
   ================================================== */

details[dropdown] {
  position: relative;
  display: inline-block;
}

details[dropdown] > summary {
  list-style: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
}

details[dropdown] > summary::-webkit-details-marker {
  display: none;
}

details[dropdown] > summary::after {
  content: '';
  display: inline-block;
  width: 0.5em;
  height: 0.5em;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg);
  transition: transform var(--transition-fast);
  margin-left: var(--space-xs);
}

details[dropdown][open] > summary::after {
  transform: rotate(-135deg);
}

details[dropdown] > menu {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 160px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  z-index: 1000;
  padding: var(--space-xs) 0;
  margin: var(--space-xs) 0 0 0;
  list-style: none;
}

details[dropdown][align="right"] > menu {
  left: auto;
  right: 0;
}

details[dropdown] > menu > li {
  margin: 0;
  padding: 0;
}

details[dropdown] > menu > li > a,
details[dropdown] > menu > li > button {
  display: block;
  width: 100%;
  padding: var(--space-sm) var(--space-md);
  color: var(--text);
  text-decoration: none;
  text-align: left;
  background: none;
  border: none;
  font-size: var(--text-base);
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

details[dropdown] > menu > li > a:hover,
details[dropdown] > menu > li > button:hover {
  background-color: var(--gray-100);
  text-decoration: none;
}

details[dropdown] > menu > li[divider] {
  border-top: 1px solid var(--border);
  margin: var(--space-xs) 0;
}

/* ==================================================
   26. Bottom Navigation
   ================================================== */

nav[position="bottom"] {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  display: flex;
  justify-content: space-around;
  align-items: center;
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: var(--space-sm);
  padding-bottom: calc(var(--space-sm) + var(--safe-bottom));
  z-index: 1000;
}

nav[position="bottom"] a,
nav[position="bottom"] button {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-sm);
  min-width: 64px;
  color: var(--muted);
  text-decoration: none;
  font-size: var(--text-xs);
  font-weight: 500;
  background: none;
  border: none;
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast);
}

nav[position="bottom"] a:hover,
nav[position="bottom"] button:hover,
nav[position="bottom"] a[aria-current="page"],
nav[position="bottom"] a.active {
  color: var(--primary);
}

nav[position="bottom"] [icon] {
  font-size: 1.5rem;
}

/* Body padding when bottom nav present */
body[has-bottom-nav] {
  padding-bottom: calc(64px + var(--safe-bottom));
}

/* ==================================================
   27. Icon Utilities
   ================================================== */

[icon] {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1em;
  height: 1em;
  fill: currentColor;
  vertical-align: -0.125em;
  flex-shrink: 0;
}

[icon="xs"] { width: 0.75em; height: 0.75em; }
[icon="sm"] { width: 0.875em; height: 0.875em; }
[icon="lg"] { width: 1.25em; height: 1.25em; }
[icon="xl"] { width: 1.5em; height: 1.5em; }
[icon="2xl"] { width: 2em; height: 2em; }

/* Emoji sizing */
[emoji] {
  font-style: normal;
  line-height: 1;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

[emoji="xs"] { font-size: 1em; }
[emoji="sm"] { font-size: 1.25em; }
[emoji="md"] { font-size: 1.5em; }
[emoji="lg"] { font-size: 2em; }
[emoji="xl"] { font-size: 3em; }
[emoji="2xl"] { font-size: 4em; }

/* Icon grid for emoji/icon display */
[icon-grid] {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
  gap: var(--space-md);
}

[icon-grid] > * {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: var(--space-xs);
}

/* ==================================================
   28. Card Structure (Article Header/Footer)
   ================================================== */

article > header {
  border-bottom: 1px solid var(--border);
  padding-bottom: var(--space-md);
  margin-bottom: var(--space-md);
}

article > header:first-child {
  margin-top: 0;
}

article > header h1,
article > header h2,
article > header h3,
article > header h4,
article > header h5,
article > header h6 {
  margin-top: 0;
  margin-bottom: var(--space-xs);
}

article > header p:last-child {
  margin-bottom: 0;
}

article > footer {
  border-top: 1px solid var(--border);
  padding-top: var(--space-md);
  margin-top: var(--space-md);
}

article > footer:last-child {
  margin-bottom: 0;
}

/* Card title/subtitle attributes */
[card-title] {
  font-size: var(--text-lg);
  font-weight: 700;
  margin: 0 0 var(--space-xs) 0;
  line-height: var(--leading-tight);
}

[card-subtitle] {
  font-size: var(--text-sm);
  color: var(--muted);
  margin: 0;
}

/* ==================================================
   29. Link Variants
   ================================================== */

a[variant="subtle"] {
  color: var(--muted);
  font-weight: 400;
}

a[variant="subtle"]:hover {
  color: var(--text);
}

a[variant="contrast"] {
  color: white;
}

a[variant="contrast"]:hover {
  color: var(--gray-200);
  text-decoration: underline;
}

a[variant="muted"] {
  color: var(--muted);
}

a[variant="muted"]:hover {
  color: var(--primary);
}

/* External link indicator */
a[external]::after {
  content: " ↗";
  font-size: 0.75em;
  vertical-align: super;
  opacity: 0.7;
}

a[external]:hover::after {
  opacity: 1;
}

/* Disabled link */
a[disabled] {
  color: var(--gray-400);
  pointer-events: none;
  cursor: not-allowed;
  text-decoration: none;
}

/* Link with icon */
a[icon-link] {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
}

/* Block link (full clickable area) */
a[block] {
  display: block;
  text-decoration: none;
}

a[block]:hover {
  text-decoration: none;
}

/* ==================================================
   30. General Loading State
   ================================================== */

[loading]:not(button) {
  position: relative;
  pointer-events: none;
  opacity: 0.6;
}

[loading]:not(button)::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 1.5rem;
  height: 1.5rem;
  margin: -0.75rem 0 0 -0.75rem;
  border: 2px solid var(--border);
  border-radius: 50%;
  border-top-color: var(--primary);
  animation: spin 0.6s linear infinite;
}

/* Loading overlay variant */
[loading="overlay"]::before {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(var(--surface), 0.8);
  backdrop-filter: blur(2px);
  z-index: 1;
}

[loading="overlay"]::after {
  z-index: 2;
}

/* Small loading spinner */
[loading="sm"]::after {
  width: 1rem;
  height: 1rem;
  margin: -0.5rem 0 0 -0.5rem;
}

/* Large loading spinner */
[loading="lg"]::after {
  width: 2.5rem;
  height: 2.5rem;
  margin: -1.25rem 0 0 -1.25rem;
  border-width: 3px;
}

/* ==================================================
   31. Image Utilities
   ================================================== */

img[fluid],
[fluid] > img,
picture[fluid] > img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Prevent image drag on iOS */
img[no-drag] {
  -webkit-user-drag: none;
  user-select: none;
  -webkit-touch-callout: none;
  -webkit-tap-highlight-color: transparent;
}

/* Object fit utilities */
img[fit="cover"] { object-fit: cover; }
img[fit="contain"] { object-fit: contain; }
img[fit="fill"] { object-fit: fill; }
img[fit="scale-down"] { object-fit: scale-down; }

/* Aspect ratio containers */
[aspect="square"] { aspect-ratio: 1 / 1; }
[aspect="video"] { aspect-ratio: 16 / 9; }
[aspect="portrait"] { aspect-ratio: 3 / 4; }
[aspect="landscape"] { aspect-ratio: 4 / 3; }

/* Scroll container */
[scroll] {
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
  scrollbar-width: thin;
}

[scroll-x] {
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior-x: contain;
}

[scroll="hidden"] {
  overflow: hidden;
}

/* Scroll snap */
[scroll-snap] {
  scroll-snap-type: x mandatory;
}

[scroll-snap] > * {
  scroll-snap-align: start;
}

/* ==================================================
   32. Keyboard Navigation Styling
   ================================================== */

/* Enhanced focus when keyboard navigating */
[keyboard-nav] :focus {
  outline: 3px solid rgba(var(--primary-rgb), 0.5);
  outline-offset: 2px;
}

/* Remove focus ring for mouse/touch users */
[keyboard-nav] :focus:not(:focus-visible) {
  outline: none;
}

/* Skip to main content link */
[skip-link] {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  background: var(--primary);
  color: white;
  border-radius: var(--radius-sm);
  z-index: 9999;
  text-decoration: none;
  font-weight: 700;
}

[skip-link]:focus {
  top: var(--space-md);
}

/* ==================================================
   33. CSS-Only Tooltip Fallback
   ================================================== */

[data-tooltip][css-tooltip] {
  position: relative;
}

[data-tooltip][css-tooltip]::before {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%);
  padding: var(--space-xs) var(--space-sm);
  background: var(--gray-900);
  color: white;
  font-size: var(--text-sm);
  font-weight: 500;
  white-space: nowrap;
  border-radius: var(--radius-sm);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-fast), visibility var(--transition-fast);
  pointer-events: none;
  z-index: 1000;
}

[data-tooltip][css-tooltip]::after {
  content: '';
  position: absolute;
  bottom: calc(100% + 2px);
  left: 50%;
  transform: translateX(-50%);
  border: 6px solid transparent;
  border-top-color: var(--gray-900);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-fast), visibility var(--transition-fast);
  pointer-events: none;
  z-index: 1000;
}

@media (hover: hover) {
  [data-tooltip][css-tooltip]:hover::before,
  [data-tooltip][css-tooltip]:hover::after {
    opacity: 1;
    visibility: visible;
  }
}

[data-tooltip][css-tooltip]:focus-visible::before,
[data-tooltip][css-tooltip]:focus-visible::after {
  opacity: 1;
  visibility: visible;
}