/* ============================================
   BASE STYLES - Reset & Defaults
   ============================================ */

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

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

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

/* Typography Defaults */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-bold);
  line-height: var(--leading-tight);
  color: var(--color-text);
  margin-bottom: var(--space-md);
}

h1 {
  font-size: var(--text-5xl);
  letter-spacing: -0.02em;
}

h2 {
  font-size: var(--text-4xl);
  letter-spacing: -0.01em;
}

h3 {
  font-size: var(--text-3xl);
}

h4 {
  font-size: var(--text-2xl);
}

h5 {
  font-size: var(--text-xl);
}

h6 {
  font-size: var(--text-lg);
}

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

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

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

a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--border-radius-sm);
}

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

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

/* Images */
img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Buttons */
button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

/* Form Elements */
input, textarea, select {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

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

/* Scrollbar - Webkit */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg-alt);
}

::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: var(--border-radius-full);
}

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

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

/* Focus visible for keyboard navigation */
*:focus-visible {
  outline: 2px solid var(--color-primary);
  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;
  }
}

/* Responsive Typography */
@media (max-width: 768px) {
  h1 {
    font-size: var(--text-4xl);
  }

  h2 {
    font-size: var(--text-3xl);
  }

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

  h4 {
    font-size: var(--text-xl);
  }
}

@media (max-width: 480px) {
  h1 {
    font-size: var(--text-3xl);
  }

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