/**
 * base.css - Reset, Typography, Utilities, Animations
 * coOCR/HTR Design System v2.1
 */

/* ==========================================================================
   RESET
   ========================================================================== */

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-size: var(--text-base);
  line-height: 1.5;
  height: 100vh;
  overflow: hidden;
}

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

h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -0.01em;
}

h1 { font-size: var(--text-2xl); }
h2 { font-size: var(--text-xl); }
h3 { font-size: var(--text-lg); }

a {
  color: var(--accent-primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* ==========================================================================
   ACCESSIBILITY - Skip Link
   ========================================================================== */

.skip-link {
  position: absolute;
  top: -100%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-primary);
  color: var(--bg-primary);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
  font-weight: 600;
  z-index: 9999;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: var(--space-2);
  text-decoration: none;
}

code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--surface-active);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
}

/* ==========================================================================
   UTILITIES
   ========================================================================== */

.hidden {
  display: none !important;
}

/* Display utilities for visibility toggle patterns */
.d-none { display: none !important; }
.d-block { display: block; }
.d-flex { display: flex; }
.d-inline { display: inline; }
.d-inline-flex { display: inline-flex; }

/* Visibility toggle classes (used with JS) */
[hidden] { display: none !important; }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* Text utilities */
.text-primary { color: var(--text-primary); }
.text-secondary { color: var(--text-secondary); }
.text-accent { color: var(--accent-primary); }
.text-confident { color: var(--confident); }
.text-uncertain { color: var(--uncertain); }
.text-problematic { color: var(--problematic); }

/* Font utilities */
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-mono { font-family: var(--font-mono); }

/* Size utilities */
.text-xs { font-size: var(--text-xs); }
.text-sm { font-size: var(--text-sm); }
.text-base { font-size: var(--text-base); }
.text-lg { font-size: var(--text-lg); }

/* ==========================================================================
   SCROLLBAR
   ========================================================================== */

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

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

::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary);
}

/* Firefox */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--border-emphasis) transparent;
}

/* ==========================================================================
   FOCUS STATES (Accessibility)
   ========================================================================== */

:focus-visible {
  outline: var(--focus-ring-width) solid var(--focus-ring-color);
  outline-offset: var(--focus-ring-offset);
}

button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
[role="button"]:focus-visible {
  outline: var(--focus-ring-width) solid var(--focus-ring-color);
  outline-offset: 1px;
}

/* Remove default focus for mouse users */
:focus:not(:focus-visible) {
  outline: none;
}

/* ==========================================================================
   ANIMATIONS
   ========================================================================== */

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes fadeOut {
  from { opacity: 1; }
  to { opacity: 0; }
}

@keyframes scaleIn {
  from { transform: scale(0.95); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

@keyframes slideUp {
  from { transform: translateY(8px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

@keyframes slideDown {
  from { transform: translateY(-8px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

/* Animation utilities */
.animate-fadeIn { animation: fadeIn var(--transition-fast); }
.animate-scaleIn { animation: scaleIn var(--transition-fast); }
.animate-slideUp { animation: slideUp var(--transition-fast); }
.animate-spin { animation: spin 1s linear infinite; }
.animate-pulse { animation: pulse 2s ease-in-out infinite; }

/* ==========================================================================
   REDUCED MOTION (Accessibility)
   Respects user preference for 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;
  }
}