/**
 * [Variables] | [Constants] | [Dependencies] | [Integration Points]
 * - Variables: Inherited CSS tokens
 * - Constants: Reset, Typography, Accessibility focus styles
 * - Dependencies: tokens.css
 * - Integration Points: Base styling for entire HTML document
 */

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

html {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-base);
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 24px);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  background-color: var(--bg-base);
  color: var(--text-primary);
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  background-image: 
    radial-gradient(circle at 50% 0%, rgba(139, 92, 246, 0.08) 0%, transparent 60%),
    linear-gradient(to right, rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  background-size: 100% 100%, 48px 48px, 48px 48px;
}

[data-theme="light"] body {
  background-image: 
    radial-gradient(circle at 50% 0%, rgba(139, 92, 246, 0.06) 0%, transparent 60%),
    linear-gradient(to right, rgba(0, 0, 0, 0.03) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(0, 0, 0, 0.03) 1px, transparent 1px);
}

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

/* Skip link */
.skip-to-content {
  position: absolute;
  top: -100px;
  left: 16px;
  background: var(--accent-violet);
  color: #FFFFFF;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  z-index: 9999;
  font-weight: 600;
  text-decoration: none;
  transition: top var(--transition-fast);
}

.skip-to-content:focus {
  top: 16px;
}

/* Layout container */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-primary);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

h1 { font-size: clamp(2.2rem, 4.5vw, 3.8rem); font-weight: 800; }
h2 { font-size: clamp(1.8rem, 3vw, 2.5rem); }
h3 { font-size: clamp(1.3rem, 2vw, 1.7rem); }
h4 { font-size: 1.15rem; }

p {
  color: var(--text-secondary);
  line-height: 1.7;
}

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

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

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

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

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