/* Frameless image previews, fitted to the available viewport. */
dialog#viewer,
dialog.archive-image-viewer,
dialog.publication-viewer {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  height: 100dvh;
  max-width: none;
  max-height: none;
  margin: 0;
  padding: 0;
  border: 0;
  border-radius: 0;
  background: transparent;
  box-shadow: none;
  overflow: hidden;
}
dialog#viewer[open],
dialog.archive-image-viewer[open],
dialog.publication-viewer[open] {
  display: grid;
  place-items: center;
  grid-template-rows: 1fr;
}
dialog#viewer::backdrop,
dialog.archive-image-viewer::backdrop,
dialog.publication-viewer::backdrop {
  background: rgba(0, 0, 0, .9);
  backdrop-filter: none;
}
dialog#viewer > img,
dialog.archive-image-viewer > img,
dialog.publication-viewer > img {
  display: block;
  width: 100%;
  height: 100%;
  min-height: 0;
  max-width: 100%;
  max-height: 100%;
  margin: 0;
  object-fit: contain;
  pointer-events: none;
}
dialog#viewer #viewer-caption,
dialog.archive-image-viewer > p,
dialog.publication-viewer > p {
  display: none;
}
dialog.publication-viewer .publication-viewer-pages {
  position: absolute;
  bottom: .5rem;
  left: 50%;
  transform: translateX(-50%);
  margin: 0;
}
dialog#viewer .close,
dialog.archive-image-viewer .archive-image-viewer-close,
dialog.publication-viewer .publication-viewer-close {
  position: absolute;
  top: .5rem;
  right: .5rem;
  z-index: 2;
}
.frame-viewer-nav {
  position: fixed;
  top: 50%;
  z-index: 3;
  display: grid;
  place-items: center;
  width: clamp(2.75rem, 4vw, 3.5rem);
  height: clamp(2.75rem, 4vw, 3.5rem);
  padding: 0;
  border: 1px solid rgba(255,255,255,.72);
  border-radius: 50%;
  background: rgba(0,0,0,.7);
  color: #fff;
  font: 2.2rem/1 Arial,sans-serif;
  transform: translateY(-50%);
  cursor: pointer;
}
.frame-viewer-prev { left: clamp(.65rem,2vw,1.5rem); }
.frame-viewer-next { right: clamp(.65rem,2vw,1.5rem); }
.frame-viewer-nav[hidden] { display: none; }
.photo-card button.photo-open {
  display: block;
  width: 100%;
  padding: 0;
  border: 0;
  background: transparent;
  cursor: zoom-in;
}
/* The parent supplies the backdrop for framed pages; avoid doubling opacity. */
html.shell-preview-active dialog[open] {visibility:hidden}
html.shell-preview-active dialog::backdrop {background:transparent}