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

html {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  transition: background-color var(--transition-base), color var(--transition-base);
}

h1, h2, h3, h4 {
  line-height: 1.3;
  font-weight: 600;
}

h1 { font-size: var(--text-3xl); }
h2 { font-size: var(--text-2xl); }
h3 { font-size: var(--text-xl); }

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

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

code, pre {
  font-family: var(--font-mono);
}

pre {
  overflow-x: auto;
  border-radius: var(--radius-md);
}

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

input {
  font-family: inherit;
  font-size: inherit;
}

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

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

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

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

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

.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--bg-primary);
  color: var(--text-primary);
  padding: 8px 16px;
  z-index: 1000;
  transition: top 0.2s;
}
.skip-link:focus {
  top: 0;
}

.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;
}