/* === BASE RESET & TYPOGRAPHY === */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 90px;
  transition: background-color var(--duration-base) ease, color var(--duration-base) ease;
}

body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--text-primary);
  background-color: var(--bg-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  padding-top: 80px;
  transition: background-color var(--duration-base) ease, color var(--duration-base) ease;
}

img {
  display: block;
  width: 100%;
  height: auto;
}

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

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

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  line-height: var(--leading-tight);
  color: var(--text-primary);
  font-weight: 700;
}

h1 { font-size: clamp(2rem, 6vw, var(--text-6xl)); }
h2 { font-size: clamp(1.5rem, 4vw, var(--text-4xl)); }
h3 { font-size: clamp(1.25rem, 3vw, var(--text-2xl)); }
h4 { font-size: var(--text-xl); }

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

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

ul, ol {
  padding-left: 1.25rem;
  color: var(--text-secondary);
}

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

[data-theme="dark"] ::selection {
  background: var(--color-primary-light);
  color: #0D1117;
}

/* Skip Link */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  z-index: 10000;
  background: var(--color-primary);
  color: white;
  font-family: var(--font-display);
  font-weight: 600;
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: top var(--duration-fast) ease;
}

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

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

/* 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;
  }
}