:not(:defined) > * {
    display: none;
  }
  
  body {
    margin: 0;
    padding: 0;
    width: 100vw;
    height: 100vh;
     font-family: Roboto, Helvetica Neue, Arial, sans-serif;
  }
  
  model-viewer {
    width: 100%;
    height: 90%;
    background-color: #ffffff;
  }
  
  
  .progress-bar {
    display: block;
    width: 33%;
    height: 10%;
    max-height: 2%;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate3d(-50%, -50%, 0);
    border-radius: 25px;
    box-shadow: 0px 3px 10px 3px rgba(0, 0, 0, 0.5), 0px 0px 5px 1px rgba(0, 0, 0, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.9);
    background-color: rgba(0, 0, 0, 0.5);
  }
  
  .progress-bar.hide {
    visibility: hidden;
    transition: visibility 0.3s;
  }
  
  .update-bar {
    background-color: rgba(255, 255, 255, 0.9);
    width: 0%;
    height: 100%;
    border-radius: 25px;
    float: left;
    transition: width 0.3s;
  }
  
  /* Consolidated AR CTA styling for both variants */
  #ar-button, #btn-ar {
    background-image: url(ar_icon.png);
    background-repeat: no-repeat;
    background-size: 20px 20px;
    background-position: 12px 50%;
    background-color: #fff;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    white-space: nowrap;
    bottom: calc(16px + env(safe-area-inset-bottom));
    padding: clamp(8px, 2.5vw, 12px) clamp(16px, 4vw, 20px) clamp(8px, 2.5vw, 12px) 40px;
    font-family: Roboto, Helvetica Neue, Arial, sans-serif;
    font-size: clamp(12px, 2.8vw, 14px);
    color:#4285f4;
    min-height: 44px;
    line-height: 1;
    border-radius: 18px;
    border: 1px solid #DADCE0;
    box-shadow: 0 4px 16px rgba(0,0,0,0.12);
    -webkit-tap-highlight-color: transparent;
    z-index: 10;
  }
  #ar-button:hover, #btn-ar:hover { background-color: #f7f9fc; }
  #ar-button:active, #btn-ar:active { background-color: #E8EAED; }
  #ar-button:focus-visible, #btn-ar:focus-visible { outline: 2px solid #4285f4; outline-offset: 2px; }
  #btn-ar { display: none; } /* toggled by JS in index-revised.html */
  
  @keyframes circle {
    from { transform: translateX(-50%) rotate(0deg) translateX(50px) rotate(0deg); }
    to   { transform: translateX(-50%) rotate(360deg) translateX(50px) rotate(-360deg); }
  }
  
  @keyframes elongate {
    from { transform: translateX(100px); }
    to   { transform: translateX(-100px); }
  }
  
  model-viewer > #ar-prompt {
    position: absolute;
    left: 50%;
    bottom: 60px;
    animation: elongate 2s infinite ease-in-out alternate;
    display: none;
  }
  
  model-viewer[ar-status="session-started"] > #ar-prompt {
    display: block;
  }
  
  model-viewer > #ar-prompt > img {
    animation: circle 4s linear infinite;
  }

  /* Responsive generic button style */
  .button{
    border-radius: 10px; 
    border: 1px solid rgba(0,0,0,0.12);
    color: #fff;
    font-size: clamp(12px, 2.8vw, 16px);
    line-height: 1;
    padding: clamp(10px, 2.8vw, 14px) clamp(14px, 4vw, 18px);
    min-height: 44px;
    min-width: 44px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.12);
    background-clip: padding-box;
    -webkit-tap-highlight-color: transparent;
  }
  
  .top-left{
    position: absolute;
    top: calc(1em + env(safe-area-inset-top));
    left: calc(1em + env(safe-area-inset-left));
    z-index: 10;
  }
  
  .top-right{
    position: absolute;
    top: calc(1em + env(safe-area-inset-top));
    right: calc(1em + env(safe-area-inset-right));
    z-index: 10;
  }
  .bottom-center{
    position: absolute;
    bottom: calc(1em + env(safe-area-inset-bottom));
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
  }
  
  .button-black{ background-color:#000; }
  .button-red{ background-color:#e53935; }
  .button-blue{ background-color:#1e88e5; }

  /* Small-screen adjustments */
  @media (max-width: 640px) {
    .top-left { top: calc(0.5em + env(safe-area-inset-top)); left: calc(0.5em + env(safe-area-inset-left)); }
    .top-right { top: calc(0.5em + env(safe-area-inset-top)); right: calc(0.5em + env(safe-area-inset-right)); }
    .bottom-center { bottom: calc(0.5em + env(safe-area-inset-bottom)); }
    #ar-button, #btn-ar { bottom: calc(8px + env(safe-area-inset-bottom)); }
  }

  /* Three.js viewer styles (index-test.php) */
  #three-container { position: fixed; inset: 0; background: #ffffff; }

  /* Top-right UI stack */
  #ui-top-right {
    position: fixed;
    top: calc(12px + env(safe-area-inset-top));
    right: calc(12px + env(safe-area-inset-right));
    display: flex;
    flex-direction: column;
    gap: 8px;
    z-index: 20;
    align-items: flex-end;
  }
  #ui-top-right .button { font-size: 14px; line-height: 1; padding: 8px 12px; border-radius: 10px; }

  /* Download group */
  #download-group { display: flex; flex-direction: column; gap: 6px; align-items: flex-end; }
  #download-group .download-label {
    font-size: 12px;
    color: #333;
    opacity: 0.8;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    background: rgba(255, 255, 255, 0.6);
    padding: 2px 8px;
    border-radius: 8px;
    backdrop-filter: blur(4px);
  }
  #download-group .download-actions { display: flex; gap: 6px; }
  #download-group .download-actions .button { font-size: 12px; padding: 6px 10px; min-height: 36px; border-radius: 10px; }

  /* Bottom-left image plane controls */
  #imagePlaneControls {
    position: absolute;
    left: calc(12px + env(safe-area-inset-left));
    bottom: calc(12px + env(safe-area-inset-bottom));
    z-index: 20;
    display: flex;
    gap: 8px;
    align-items: center;
  }
  #imagePlaneControls .button { padding: 8px 12px; border-radius: 10px; }

  /* Enhanced button theming */
  #ui-top-right .button, #imagePlaneControls .button, #editAppBtn {
    appearance: none;
    border: 1px solid rgba(0, 0, 0, 0.12);
    border-radius: 12px;
    padding: 10px 14px;
    font-weight: 600;
    letter-spacing: 0.02em;
    color: #fff;
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.12), inset 0 1px 0 rgba(255, 255, 255, 0.06);
    transition: transform 0.08s ease, box-shadow 0.2s ease, filter 0.2s ease, opacity 0.2s ease;
    backdrop-filter: saturate(120%) blur(6px);
    -webkit-font-smoothing: antialiased;
  }
  #ui-top-right .button:hover, #imagePlaneControls .button:hover, #editAppBtn:hover {
    box-shadow: 0 10px 24px rgba(0, 0, 0, 0.16);
    filter: brightness(1.05);
  }
  #ui-top-right .button:active, #imagePlaneControls .button:active, #editAppBtn:active {
    transform: translateY(1px) scale(0.995);
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.12);
    filter: brightness(0.98);
  }
  #ui-top-right .button:focus-visible, #imagePlaneControls .button:focus-visible, #editAppBtn:focus-visible {
    outline: 2px solid rgba(66, 133, 244, 0.9);
    outline-offset: 2px;
  }

  /* Color variants */
  #ui-top-right .button.button-red, #imagePlaneControls .button.button-red {
    background: linear-gradient(180deg, #f66a66 0%, #e53935 100%);
    border-color: rgba(229, 57, 53, 0.6);
  }
  #ui-top-right .button.button-blue, #imagePlaneControls .button.button-blue {
    background: linear-gradient(180deg, #4aa3ff 0%, #1e88e5 100%);
    border-color: rgba(30, 136, 229, 0.6);
  }
  #ui-top-right .button.button-black, #imagePlaneControls .button.button-black, #editAppBtn.button-black {
    background: linear-gradient(180deg, #3a3a3a 0%, #111 100%);
    border-color: rgba(17, 17, 17, 0.6);
  }

  /* Loader overlay */
  #loaderOverlay {
    position: fixed;
    inset: 0;
    background: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    opacity: 1;
    transition: opacity 250ms ease;
  }
  #loaderOverlay.hidden { opacity: 0; pointer-events: none; }
  #loaderOverlay .loader-box { display: flex; flex-direction: column; align-items: center; gap: 10px; }
  #loaderOverlay img {
    width: 56px;
    height: auto;
    aspect-ratio: 1 / 1;
    object-fit: contain;
    flex: 0 0 auto;
    image-rendering: -webkit-optimize-contrast;
    image-rendering: crisp-edges;
  }
  #loaderOverlay .version {
    position: absolute;
    bottom: calc(20px + env(safe-area-inset-bottom));
    font-size: 11px;
    color: #999;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    letter-spacing: 0.02em;
  }

  /* Edit button positioning */
  #editAppBtn {
    position: fixed;
    top: calc(12px + env(safe-area-inset-top));
    left: calc(12px + env(safe-area-inset-left));
    z-index: 20;
  }

  /* Responsive adjustments for Three.js viewer */
  @media (max-width: 600px) {
    #ui-top-right {
      gap: 6px;
      top: calc(8px + env(safe-area-inset-top));
      right: calc(8px + env(safe-area-inset-right));
      /* Ensure visibility on mobile */
      z-index: 30;
      pointer-events: auto;
    }
    #ui-top-right .button { 
      font-size: 12px; 
      padding: 8px 10px;
      /* Ensure buttons are touchable */
      min-height: 44px;
      min-width: 44px;
    }
    #download-group .download-label { font-size: 11px; }
    #download-group .download-actions .button { 
      font-size: 11px; 
      padding: 6px 10px; 
      min-height: 44px;
      min-width: 44px;
    }
    #imagePlaneControls {
      left: calc(8px + env(safe-area-inset-left));
      bottom: calc(8px + env(safe-area-inset-bottom));
      gap: 6px;
      z-index: 30;
    }
    #ui-top-right .button, #imagePlaneControls .button, #editAppBtn { 
      padding: 8px 10px; 
      border-radius: 10px;
      /* Fallback for browsers that don't support backdrop-filter */
      background-color: rgba(0, 0, 0, 0.9);
    }
    #download-group .download-actions .button { padding: 6px 10px; }
    #editAppBtn {
      top: calc(8px + env(safe-area-inset-top));
      left: calc(8px + env(safe-area-inset-left));
      min-height: 44px;
      min-width: 44px;
      z-index: 30;
    }
  }

  @media (max-width: 380px) {
    #ui-top-right {
      gap: 4px;
      top: calc(6px + env(safe-area-inset-top));
      right: calc(6px + env(safe-area-inset-right));
      z-index: 30;
    }
    #ui-top-right .button { 
      font-size: 11px; 
      padding: 6px 8px;
      min-height: 44px;
      min-width: 44px;
    }
    #download-group .download-label { font-size: 10px; }
    #download-group .download-actions .button { 
      font-size: 10px; 
      padding: 5px 8px; 
      min-height: 44px;
      min-width: 44px;
    }
    #imagePlaneControls {
      left: calc(6px + env(safe-area-inset-left));
      bottom: calc(6px + env(safe-area-inset-bottom));
      gap: 4px;
      z-index: 30;
    }
    #ui-top-right .button, #imagePlaneControls .button, #editAppBtn { 
      padding: 6px 8px; 
      border-radius: 9px;
      background-color: rgba(0, 0, 0, 0.9);
    }
    #download-group .download-actions .button { padding: 5px 8px; }
    #editAppBtn {
      top: calc(6px + env(safe-area-inset-top));
      left: calc(6px + env(safe-area-inset-left));
      min-height: 44px;
      min-width: 44px;
      z-index: 30;
    }
  }