/* 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;
}

/* Button base — applies to all .btn variants */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 12px 28px;
  border-radius: var(--radius-sm);  /* 2px */
  font-family: var(--font-body);
  font-size: var(--text-label);     /* 14px */
  font-weight: var(--fw-semibold);  /* 600 */
  letter-spacing: 0.04em;
  line-height: var(--lh-label);
  cursor: pointer;
  border: none;
  text-decoration: none;
  transition: var(--transition-base);
  min-height: 44px;                 /* RESP-04: touch target minimum */
  white-space: nowrap;
}

/* Primary button — gold background, carbon text */
.btn--primary {
  background-color: var(--color-gold-500);
  color: var(--color-carbon);
  border: none;
}

.btn--primary:hover,
.btn--primary:focus-visible {
  background-color: var(--color-gold-300);
  transform: translateY(-1px);
}

/* Ghost button — transparent, white border (for dark backgrounds) */
.btn--ghost {
  background-color: transparent;
  color: var(--color-white);
  border: 1.5px solid var(--color-white);
}

.btn--ghost:hover,
.btn--ghost:focus-visible {
  background-color: rgba(255, 255, 255, 0.10);
}

/* Ghost dark button — transparent, carbon border (for light backgrounds) */
.btn--ghost-dark {
  background-color: transparent;
  color: var(--color-carbon);
  border: 1.5px solid var(--color-carbon);
}

.btn--ghost-dark:hover,
.btn--ghost-dark:focus-visible {
  background-color: rgba(21, 24, 28, 0.08);
}

/* Fade-in animation — triggered by IntersectionObserver adding .is-visible */
.fade-in {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

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

/* Visually hidden until JS loads — for progressive enhancement sections */
.js-only {
  display: none;
}