/* Intro only: preserve the existing header offset and every following section. */
.swipe-page .video-intro {
  height: 100lvh;
  min-height: 100lvh;
  max-height: 100lvh;
  margin-top: calc(-1 * var(--header-height));
  margin-bottom: var(--header-height);
  padding: 0;
  overflow: hidden;
  background: #00376c;
}
.video-intro__media {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.swipe-page.intro-active .header {
  visibility: hidden;
  pointer-events: none;
}
.video-intro__scroll {
  position: absolute;
  bottom: max(28px, env(safe-area-inset-bottom));
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  color: #fff;
  font: 11px/1.4 sans-serif;
  letter-spacing: .2em;
  text-shadow: 0 1px 5px #000;
}
.video-intro__arrow { font-size: 24px; animation: intro-arrow 2s ease-in-out infinite; }
@keyframes intro-arrow { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(6px); } }
@media (prefers-reduced-motion: reduce) {
  .video-intro__arrow { animation: none; }
}

/* Fade the fixed header in without changing the page geometry. */
.swipe-page .header {
  transition: opacity .2s ease, visibility .2s;
}
.swipe-page.intro-active .header { opacity: 0; }
@media (prefers-reduced-motion: reduce) {
  .swipe-page .header { transition: none; }
}

/* Isolate the video paint layer from the rest of the document. */
.swipe-page .video-intro { contain: paint; isolation: isolate; }
.video-intro__media { position: absolute; inset: 0; }
.video-intro__media.is-offscreen { visibility: hidden; }