/*
 * Full-screen diagram lightbox. Pairs with diagram-lightbox.js.
 *
 * Every colour here is a Material CSS variable, so the overlay follows the
 * site's light/dark palette with no second set of rules and no hardcoded hex
 * that would go unreadable in one scheme.
 */

/* ---------------------------------------------------------- the trigger */

[data-zoomable] {
  position: relative;
  cursor: zoom-in;
}

.dlb-expand {
  position: absolute;
  top: 0.35rem;
  right: 0.35rem;
  width: 1.9rem;
  height: 1.9rem;
  border: 1px solid var(--md-default-fg-color--lightest);
  border-radius: 0.25rem;
  background: var(--md-default-bg-color);
  color: var(--md-default-fg-color--light);
  font-size: 1rem;
  line-height: 1;
  cursor: zoom-in;
  opacity: 0;
  transition: opacity 0.15s ease;
}

[data-zoomable]:hover .dlb-expand,
[data-zoomable]:focus-within .dlb-expand {
  opacity: 1;
}

/* Keyboard users never trigger :hover, so the affordance has to be reachable
   without a pointer. */
.dlb-expand:focus-visible {
  opacity: 1;
  outline: 2px solid var(--md-accent-fg-color);
  outline-offset: 2px;
}

/* ---------------------------------------------------------- the overlay */

.dlb {
  position: fixed;
  inset: 0;
  z-index: 10000;
  display: none;
  flex-direction: column;
  background: color-mix(in srgb, var(--md-default-bg-color) 92%, transparent);
  backdrop-filter: blur(6px);
}

.dlb.is-open {
  display: flex;
}

html.dlb-open {
  overflow: hidden;
}

.dlb__bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.6rem 1rem;
  color: var(--md-default-fg-color--light);
  font-size: 0.7rem;
}

.dlb__close {
  border: 0;
  background: transparent;
  color: var(--md-default-fg-color);
  font-size: 1.3rem;
  line-height: 1;
  padding: 0.3rem 0.6rem;
  border-radius: 0.25rem;
  cursor: pointer;
}

.dlb__close:hover,
.dlb__close:focus-visible {
  background: var(--md-default-fg-color--lightest);
  outline: none;
}

.dlb__stage {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  touch-action: none;          /* let the JS own pan and zoom gestures */
}

.dlb__stage svg {
  max-width: none !important;  /* beats Material's img/svg width cap */
  transform-origin: center center;
  transition: none;            /* transitions fight per-frame drag updates */
  user-select: none;
}

/* The hint text is the only thing that has to go on small screens; the
   gestures still work. */
@media screen and (max-width: 46.1875em) {
  .dlb__hint {
    display: none;
  }
}