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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
}

img, video, svg {
  max-width: 100%;
  height: auto;
  display: block;
}

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

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input, select, textarea {
  font-family: inherit;
  font-size: inherit;
}

ul, ol {
  list-style: none;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-primary);
}

h1 { font-size: 3rem; }
h2 { font-size: 2.25rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.25rem; }

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

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

/* Utility Classes */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.container--narrow {
  max-width: var(--container-narrow);
}

.text-center { text-align: center; }
.text-muted { color: var(--color-text-muted); }
.text-accent { color: var(--color-accent); }
.text-primary { color: var(--color-primary); }

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

.section {
  padding: var(--space-4xl) 0;
}

.section--dark {
  background-color: var(--color-primary);
  color: var(--color-text-light);
}

.section--dark h2,
.section--dark h3,
.section--dark h4 {
  color: var(--color-text-light);
}

.section--alt {
  background-color: var(--color-surface-alt);
}

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }
.gap-xl { gap: var(--space-xl); }

/* Accessibility — Focus indicators */
:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

button:focus-visible, a:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

/* Skip to main content link */
.skip-link {
  position: absolute;
  top: -100px;
  left: 0;
  background: var(--color-accent);
  color: var(--color-primary);
  padding: 0.75rem 1.5rem;
  z-index: 9999;
  font-weight: 700;
  transition: top 0.2s;
}

.skip-link:focus {
  top: 0;
}

/* 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 (forced-colors: active) {
  .btn--primary, .btn--secondary, .badge, .chip.active {
    border: 2px solid ButtonText;
  }
  .progress-step__circle {
    border: 2px solid ButtonText;
  }
}

/* Prefers contrast */
@media (prefers-contrast: high) {
  :root {
    --color-text-muted: #4B5563;
    --color-border: #9CA3AF;
  }
  .btn--outline {
    border-width: 3px;
  }
}

/* Touch target sizing for mobile */
@media (pointer: coarse) {
  .btn--small {
    min-height: 44px;
    min-width: 44px;
  }
  .chip {
    min-height: 44px;
  }
  .header__nav a {
    min-height: 44px;
    display: inline-flex;
    align-items: center;
  }
}

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