/* ── 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-body);
  font-size: var(--fs-base);
  line-height: var(--lh-normal);
  color: var(--color-text-primary);
  background-color: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: inherit;
  text-decoration: none;
}

ul,
ol {
  list-style: none;
}

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

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

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: var(--lh-tight);
  letter-spacing: var(--ls-tight);
  color: var(--color-text-primary);
}

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

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

.section {
  padding-block: var(--sp-24);
}

.section--sm {
  padding-block: var(--sp-16);
}

.section--dark {
  background-color: var(--color-primary);
}

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

.section--surface-2 {
  background-color: var(--color-surface-2);
}

/* ── Typography Scale ────────────────────────────────────── */
.text-xs   { font-size: var(--fs-xs); }
.text-sm   { font-size: var(--fs-sm); }
.text-base { font-size: var(--fs-base); }
.text-lg   { font-size: var(--fs-lg); }
.text-xl   { font-size: var(--fs-xl); }
.text-2xl  { font-size: var(--fs-2xl); }
.text-3xl  { font-size: var(--fs-3xl); }
.text-4xl  { font-size: var(--fs-4xl); }

.font-medium  { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold    { font-weight: 700; }

.text-muted     { color: var(--color-text-muted); }
.text-secondary { color: var(--color-text-secondary); }
.text-accent    { color: var(--color-accent); }
.text-white     { color: var(--color-white); }

.text-center { text-align: center; }

/* ── Accessibility ───────────────────────────────────────── */
.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;
}

/* ── Scroll Animations ───────────────────────────────────── */
.fade-up {
  opacity: 0;
  transform: translateY(28px);
  transition:
    opacity  0.65s var(--ease),
    transform 0.65s var(--ease);
}

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

.fade-in {
  opacity: 0;
  transition: opacity 0.65s var(--ease);
}

.fade-in.visible {
  opacity: 1;
}

/* Stagger delays for child elements */
.stagger-children > *:nth-child(1) { transition-delay: 0ms; }
.stagger-children > *:nth-child(2) { transition-delay: 100ms; }
.stagger-children > *:nth-child(3) { transition-delay: 200ms; }
.stagger-children > *:nth-child(4) { transition-delay: 300ms; }
.stagger-children > *:nth-child(5) { transition-delay: 400ms; }
.stagger-children > *:nth-child(6) { transition-delay: 500ms; }

/* Respect user motion preference */
@media (prefers-reduced-motion: reduce) {
  .fade-up,
  .fade-in {
    opacity: 1;
    transform: none;
    transition: none;
  }
}