/* ============================================================
   Common / reset styles — shared across all pages
   ============================================================ */

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

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

body {
  margin: 0;
  font-family: var(--font-primary);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  line-height: var(--line-height-normal);
  color: var(--color-text-primary);
  background-color: var(--color-bg-default);
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--duration-fast) var(--ease-out);
}

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  padding: 0;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  margin: 0;
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  letter-spacing: var(--letter-spacing-tight);
}

p {
  margin: 0;
}

/* Skip link for keyboard accessibility */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--spacing-md);
  z-index: var(--z-modal);
  padding: var(--spacing-sm) var(--spacing-md);
  background: var(--color-accent);
  color: var(--color-accent-contrast);
  border-radius: var(--radius-md);
}

.skip-link:focus {
  top: var(--spacing-md);
}

/* Screen-reader only */
.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;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  min-height: 44px;
  padding: 12px 24px;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  line-height: 1;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  transition:
    background-color var(--duration-fast) var(--ease-out),
    color var(--duration-fast) var(--ease-out),
    border-color var(--duration-fast) var(--ease-out),
    transform var(--duration-fast) var(--ease-out);
}

.btn:hover {
  color: inherit;
}

.btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.btn--primary {
  background-color: var(--color-accent);
  color: var(--color-accent-contrast);
}

.btn--primary:hover {
  background-color: var(--color-accent-dark);
  color: var(--color-accent-contrast);
}

.btn--ghost {
  background-color: transparent;
  color: var(--color-accent-dark);
  border-color: var(--color-accent);
}

.btn--ghost:hover {
  background-color: var(--color-accent-soft);
  color: var(--color-accent-dark);
  border-color: var(--color-accent-dark);
}

.btn--outline {
  background-color: transparent;
  color: var(--color-accent-dark);
  border-color: var(--color-accent);
}

.btn--outline:hover {
  background-color: var(--color-accent);
  color: var(--color-accent-contrast);
}

/* Section headings */
.section-heading {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
}

.section-lead {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  max-width: 36em;
  line-height: var(--line-height-relaxed);
}

@media (min-width: 768px) {
  .section-heading {
    font-size: var(--font-size-3xl);
  }
}

/* Motion: fade-up on scroll (respect reduced motion) */
@keyframes fade-up {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.reveal {
  opacity: 0;
  transform: translateY(16px);
}

.reveal.is-visible {
  /* --reveal-delay lets sibling sections stagger without extra JS */
  animation: fade-up var(--duration-slow) var(--ease-out) var(--reveal-delay, 0s) both;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .reveal,
  .reveal.is-visible {
    opacity: 1;
    transform: none;
    animation: none;
  }
}