/* ==========================================================================
   Base — Reset, Typography, Global Styles
   ========================================================================== */

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

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

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

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

ul,
ol {
  list-style: none;
}

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

input,
textarea {
  font-family: inherit;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: var(--color-text-primary);
}

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

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

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

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

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

code {
  font-family: var(--font-mono);
  font-size: 0.9em;
}

/* Layout */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

section {
  padding: var(--space-24) 0;
}

/* Section Headings */
.section-header {
  text-align: center;
  margin-bottom: var(--space-16);
}

.section-header h2 {
  margin-bottom: var(--space-4);
}

.section-header p {
  font-size: var(--font-size-lg);
  max-width: 640px;
  margin: 0 auto;
}

/* Scroll Reveal Animations */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Selection */
::selection {
  background: rgba(79, 70, 229, 0.4);
  color: var(--color-text-primary);
}

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

/* Screen reader only utility */
.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;
}