/* ============================================
   ASR Library Stylesheet
   Designed for WCAG 2.2 AAA compliance
   ============================================ */

/* ----- CSS Reset & Base ----- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

:root {
  /* AAA contrast ratios (7:1 for normal text, 4.5:1 for large) */
  --color-text: #1a1a1a;
  --color-bg: #ffffff;
  --color-link: #0051a3;
  --color-link-visited: #6b1c7a;
  --color-link-hover: #003d7a;
  --color-focus: #ffbf47;
  --color-border: #505050;
  --color-muted: #595959;
  
  /* Accent colors */
  --color-primary: #0051a3;
  --color-primary-hover: #003d7a;
  --color-secondary: #2a7a2a;
  --color-warning: #996300;
  --color-error: #b91c1c;
  --color-success: #166534;
  
  /* Background variants */
  --color-bg-alt: #f5f5f5;
  --color-bg-accent: #e8f0f8;
  
  /* Typography */
  --font-body: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'Courier New', Courier, monospace;
  
  /* Spacing (8px base unit) */
  --space-xs: 0.5rem;   /* 8px */
  --space-sm: 1rem;     /* 16px */
  --space-md: 1.5rem;   /* 24px */
  --space-lg: 2rem;     /* 32px */
  --space-xl: 3rem;     /* 48px */
  --space-2xl: 4rem;    /* 64px */
  
  /* Line height for readability */
  --line-height-tight: 1.3;
  --line-height-normal: 1.5;
  --line-height-loose: 1.8;
  
  /* Border radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
}

/* ----- Skip Links ----- */
.skip-link {
  position: absolute;
  top: -100px;
  left: 0;
  background: var(--color-focus);
  color: var(--color-text);
  padding: var(--space-xs) var(--space-sm);
  text-decoration: none;
  font-weight: 700;
  z-index: 1000;
  border-radius: var(--radius-sm);
}

.skip-link:focus {
  top: var(--space-xs);
  left: var(--space-xs);
  outline: 3px solid var(--color-text);
  outline-offset: 2px;
}

/* ----- Base Typography ----- */
html {
  font-size: 100%; /* Respect user preferences */
}

body {
  font-family: var(--font-body);
  font-size: 1.125rem; /* 18px - larger for readability */
  line-height: var(--line-height-loose);
  color: var(--color-text);
  background-color: var(--color-bg);
  margin: 0;
  padding: 0;
}

h1, h2, h3, h4, h5, h6 {
  line-height: var(--line-height-tight);
  margin-top: var(--space-xl);
  margin-bottom: var(--space-sm);
  font-weight: 700;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; margin-top: var(--space-2xl); }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

h1:first-child,
h2:first-child {
  margin-top: 0;
}

p {
  margin-top: 0;
  margin-bottom: var(--space-md);
  max-width: 75ch; /* Optimal line length for readability */
}

.lead {
  font-size: 1.25rem;
  color: var(--color-muted);
  margin-bottom: var(--space-lg);
}

/* ----- Links ----- */
a {
  color: var(--color-link);
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

a:visited {
  color: var(--color-link-visited);
}

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

a:focus {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
  background-color: var(--color-focus);
  color: var(--color-text);
}

/* ----- Focus Indicators ----- */
*:focus {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
}

*:focus:not(:focus-visible) {
  outline: none;
}

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

/* ----- Layout ----- */
header[role="banner"] {
  background-color: var(--color-bg-alt);
  border-bottom: 2px solid var(--color-border);
  padding: var(--space-sm) var(--space-md);
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
}

.site-title {
  font-size: 1.5rem;
  font-weight: 700;
  text-decoration: none;
  color: var(--color-text);
}

.site-title:hover {
  color: var(--color-link);
}

/* ----- Navigation ----- */
nav ul,
.nav-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}

nav a {
  display: inline-block;
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
}

nav a[aria-current="page"] {
  background-color: var(--color-primary);
  color: white;
  text-decoration: none;
}

/* ----- Main Content ----- */
main {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--space-lg) var(--space-md);
  min-height: calc(100vh - 300px);
}

/* ----- Footer ----- */
footer[role="contentinfo"] {
  background-color: var(--color-bg-alt);
  border-top: 2px solid var(--color-border);
  padding: var(--space-lg) var(--space-md);
  margin-top: var(--space-2xl);
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  text-align: center;
}

.footer-tagline {
  color: var(--color-muted);
  font-style: italic;
}

/* ----- Buttons ----- */
.button {
  display: inline-block;
  padding: var(--space-sm) var(--space-md);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  border: 2px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color 0.2s, border-color 0.2s;
}

.button:focus {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
}

.button-primary {
  background-color: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

.button-primary:hover {
  background-color: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
  color: white;
}

.button-primary:visited {
  color: white;
}

.button-secondary {
  background-color: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.button-secondary:hover {
  background-color: var(--color-bg-accent);
}

.button-small {
  padding: var(--space-xs) var(--space-sm);
  font-size: 0.875rem;
}

/* ----- Hero Section ----- */
.hero {
  text-align: center;
  padding: var(--space-2xl) var(--space-md);
  background-color: var(--color-bg-accent);
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-2xl);
}

.hero h1 {
  margin-top: 0;
  font-size: 3rem;
}

.hero .lead {
  max-width: 60ch;
  margin-left: auto;
  margin-right: auto;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-sm);
  margin-top: var(--space-lg);
}

/* ----- Steps Grid ----- */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-lg);
  margin: var(--space-lg) 0;
}

.step {
  background-color: var(--color-bg-alt);
  padding: var(--space-lg);
  border-radius: var(--radius-md);
  text-align: center;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 3rem;
  height: 3rem;
  background-color: var(--color-primary);
  color: white;
  font-size: 1.5rem;
  font-weight: 700;
  border-radius: 50%;
  margin-bottom: var(--space-sm);
}

.step h3 {
  margin-top: var(--space-sm);
}

/* ----- Pipeline Diagram ----- */
.pipeline-diagram {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  margin: var(--space-lg) 0;
}

.pipeline-stage {
  background-color: var(--color-bg-alt);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  text-align: center;
  min-width: 200px;
}

.pipeline-arrow {
  font-size: 2rem;
  color: var(--color-muted);
}

.stage-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  background-color: var(--color-primary);
  color: white;
  font-size: 1.25rem;
  font-weight: 700;
  border-radius: 50%;
  margin-bottom: var(--space-xs);
}

/* ----- Forms ----- */
.form-group {
  margin-bottom: var(--space-lg);
}

label {
  display: block;
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.required {
  color: var(--color-error);
}

.optional {
  color: var(--color-muted);
  font-weight: 400;
}

input[type="text"],
input[type="url"],
input[type="email"],
textarea,
select {
  width: 100%;
  max-width: 500px;
  padding: var(--space-sm);
  font-size: 1rem;
  font-family: inherit;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  background-color: var(--color-bg);
}

input:focus,
textarea:focus,
select:focus {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
  border-color: var(--color-primary);
}

.form-help {
  font-size: 0.875rem;
  color: var(--color-muted);
  margin-top: var(--space-xs);
}

.form-actions {
  margin-top: var(--space-lg);
}

/* ----- Alerts ----- */
.alert {
  padding: var(--space-md);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-lg);
}

.alert h3 {
  margin-top: 0;
}

.alert-success {
  background-color: #dcfce7;
  border: 2px solid var(--color-success);
}

.alert-error {
  background-color: #fee2e2;
  border: 2px solid var(--color-error);
}

/* ----- Cards ----- */
.video-card {
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  margin-bottom: var(--space-md);
}

.video-title {
  margin-top: 0;
  font-size: 1.25rem;
}

.video-meta {
  color: var(--color-muted);
  font-size: 0.875rem;
}

.badge {
  display: inline-block;
  padding: var(--space-xs) var(--space-sm);
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
}

.badge-warning {
  background-color: #fef3c7;
  color: var(--color-warning);
}

.badge-success {
  background-color: #dcfce7;
  color: var(--color-success);
}

/* ----- CTA Grid ----- */
.cta-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-lg);
  margin: var(--space-lg) 0;
}

.cta-card {
  background-color: var(--color-bg-alt);
  padding: var(--space-lg);
  border-radius: var(--radius-md);
  text-align: center;
}

.cta-card h3 {
  margin-top: 0;
}

/* ----- Details/Summary ----- */
details {
  margin-bottom: var(--space-md);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
}

summary {
  font-weight: 600;
  cursor: pointer;
  padding: var(--space-md);
  background-color: var(--color-bg-alt);
}

summary:hover {
  background-color: var(--color-bg-accent);
}

summary:focus {
  outline: 3px solid var(--color-focus);
  outline-offset: -3px;
}

details[open] summary {
  border-bottom: 2px solid var(--color-border);
}

details > *:not(summary) {
  padding: 0 var(--space-md);
}

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

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

.process-list li {
  margin-bottom: var(--space-md);
}

.process-list strong {
  display: block;
}

/* ----- Definition Lists ----- */
dl {
  margin-bottom: var(--space-lg);
}

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

dd {
  margin-left: 0;
  margin-bottom: var(--space-sm);
  padding-left: var(--space-md);
  border-left: 3px solid var(--color-border);
}

/* ----- Sections ----- */
section {
  margin-bottom: var(--space-2xl);
}

.empty-state {
  text-align: center;
  padding: var(--space-2xl);
  background-color: var(--color-bg-alt);
  border-radius: var(--radius-md);
}

/* ----- Filters ----- */
.catalog-filters {
  background-color: var(--color-bg-alt);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-lg);
}

fieldset {
  border: none;
  padding: 0;
  margin: 0;
}

legend {
  font-weight: 700;
  margin-bottom: var(--space-sm);
}

.filter-options {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.filter-options label {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-weight: 400;
  cursor: pointer;
}

.sort-options {
  margin-top: var(--space-md);
}

/* ----- Apply Info Box ----- */
.apply-info {
  background-color: var(--color-bg-accent);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  margin-top: var(--space-md);
}

.apply-info h3 {
  margin-top: 0;
}

/* ----- Responsive ----- */
@media (max-width: 768px) {
  body {
    font-size: 1rem;
  }
  
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
  
  .hero h1 {
    font-size: 2rem;
  }
  
  .header-container {
    flex-direction: column;
    text-align: center;
  }
  
  nav ul {
    justify-content: center;
  }
  
  .pipeline-diagram {
    flex-direction: column;
  }
  
  .pipeline-arrow {
    transform: rotate(90deg);
  }
}

/* ----- Print Styles ----- */
@media print {
  .skip-link,
  nav,
  .hero-actions,
  .form-actions,
  footer {
    display: none;
  }
  
  body {
    font-size: 12pt;
    line-height: 1.5;
    color: black;
    background: white;
  }
  
  a {
    color: black;
    text-decoration: underline;
  }
  
  a[href^="http"]::after {
    content: " (" attr(href) ")";
    font-size: 0.8em;
  }
  
  h1, h2, h3 {
    page-break-after: avoid;
  }
}

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