/* v.640 — always-live river background with frame-level dark-mode dimming. */
html[data-site-river-background="640"] {
  background: #8fc5ca url("../img/parallax0.webp?v=130") center / cover fixed no-repeat !important;
}
html[data-site-river-background="640"] body {
  position: relative !important;
  min-height: 100vh;
  isolation: isolate;
  background-color: transparent !important;
  background-image: none !important;
}
.site-river-background-v640 {
  position: fixed !important;
  inset: 0 !important;
  width: 100% !important;
  height: 100% !important;
  display: block !important;
  pointer-events: none !important;
  user-select: none !important;
  touch-action: none !important;
  border: 0 !important;
  margin: 0 !important;
  padding: 0 !important;
  z-index: -1 !important;
  opacity: 0;
  transition: opacity .16s linear !important;
}
.site-river-background-v640.is-ready { opacity: 1; }
.river-dimming-button-v640 {
  position: fixed !important;
  z-index: 2147483646 !important;
  width: 46px !important;
  height: 46px !important;
  min-width: 46px !important;
  padding: 0 !important;
  border: 1px solid rgba(255,255,255,.62) !important;
  border-radius: 50% !important;
  background: #0d5c63 !important;
  color: #fff !important;
  box-shadow: 0 8px 22px rgba(0,0,0,.30) !important;
  font: 700 15px/46px Arial, sans-serif !important;
  text-align: center !important;
  cursor: pointer !important;
  appearance: none !important;
}
.river-dimming-button-v640:hover,
.river-dimming-button-v640:focus-visible {
  background: #85401f !important;
  outline: 2px solid rgba(255,255,255,.9) !important;
  outline-offset: 2px !important;
}
.river-dimming-button-v640[hidden] { display: none !important; }
@media (max-width: 700px) {
  .river-dimming-button-v640 {
    width: 42px !important;
    height: 42px !important;
    min-width: 42px !important;
    font-size: 14px !important;
    line-height: 42px !important;
  }
}
@media print {
  .site-river-background-v640,
  .river-dimming-button-v640 { display: none !important; }
}