<meta charset="UTF-8">
  <title>Popup Slideshow</title>
  <style>
  body {
    margin: 0;
    font-family: sans-serif;
    <!--overflow: hidden; /* Prevent background scrolling */-->
  }

  /* Fullscreen canvas hidden except for centered image box */
  .overlay {
    position: fixed;
    top: 0; left: 0;
    width: 100vw; height: 100vh;
    background: transparent;  /* No overlay */
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
  }

  .slideshow-container {
  position: relative;
  width: 900px;
  height: 400px;
  background-color: #fff;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 0 25px rgba(0, 0, 0, 0.5);
  border: 10px solid orange; /* Initial color */
  animation: tricolorBlink 5s infinite;
}

<!--@keyframes tricolorBlink {
  0%   { border-color: orange; }
  33%  { border-color: white; }
  66%  { border-color: green; }
  100% { border-color: orange; }
}
-->

  .slideshow-container img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: block;
    background: #000;
  }

  .close-btn {
    position: absolute;
    top: 8px;
    right: 8px;
    background: rgba(255, 255, 255, 0.9);
    color: #000;
    border: none;
    padding: 6px 12px;
    font-size: 16px;
    border-radius: 6px;
    cursor: pointer;
    z-index: 10;
  }

  .close-btn:hover {
    background: #ddd;
  }
</style>
