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

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

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

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

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

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

ul, ol {
  list-style: none;
}

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

input, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

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

h1 {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--space-lg);
}

h2 {
  font-size: var(--font-size-3xl);
  margin-bottom: var(--space-lg);
}

h3 {
  font-size: var(--font-size-2xl);
  margin-bottom: var(--space-md);
}

h4 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--space-md);
}

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

.text-sm { font-size: var(--font-size-sm); }
.text-md { font-size: var(--font-size-md); }
.text-lg { font-size: var(--font-size-lg); }
.text-xl { font-size: var(--font-size-xl); }
.text-center { text-align: center; }
.text-uppercase {
  text-transform: uppercase;
  letter-spacing: var(--letter-spacing-wider);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
}

/* Layout */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.container--narrow {
  max-width: var(--container-narrow);
}

.container--wide {
  max-width: var(--container-wide);
}

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

.section--alt {
  background-color: var(--color-bg-alt);
}

.section--dark {
  background-color: var(--color-bg-dark);
  color: var(--color-text-on-dark);
}

.section--dark h2,
.section--dark h3,
.section--dark h4 {
  color: var(--color-white);
}

.section--dark p {
  color: rgba(255, 255, 255, 0.85);
}

.section__header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto var(--space-3xl);
}

.section__label {
  text-transform: uppercase;
  letter-spacing: var(--letter-spacing-wider);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--color-accent);
  margin-bottom: var(--space-sm);
  display: block;
}

/* Grid */
.grid {
  display: grid;
  gap: var(--space-xl);
}

.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }

/* Flex */
.flex { display: flex; }
.flex--center { align-items: center; justify-content: center; }
.flex--between { align-items: center; justify-content: space-between; }
.flex--column { flex-direction: column; }
.flex--gap-sm { gap: var(--space-sm); }
.flex--gap-md { gap: var(--space-md); }
.flex--gap-lg { gap: var(--space-lg); }
.flex--gap-xl { gap: var(--space-xl); }

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

/* Animations */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-in-left {
  opacity: 0;
  transform: translateX(-30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in-left.visible {
  opacity: 1;
  transform: translateX(0);
}

.fade-in-right {
  opacity: 0;
  transform: translateX(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in-right.visible {
  opacity: 1;
  transform: translateX(0);
}

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