Preserve the tape shadow over scrolling content

assets/construction-tape-mask.svg

@@ -0,0 +1,12 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1200 270">
+  <defs>
+    <!-- Original IDML shadow: 35% opacity, 2.7895 pt offsets, 3.945 pt blur size. -->
+    <filter id="shadow" filterUnits="userSpaceOnUse" x="-20" y="-20" width="1240" height="310" color-interpolation-filters="sRGB">
+      <feDropShadow dx="2.789536" dy="2.789536" stdDeviation="1.9725" flood-color="white" flood-opacity="0.35"/>
+    </filter>
+  </defs>
+  <g fill="white" filter="url(#shadow)">
+    <path transform="matrix(1,0,0,-1,0,134.74762)" d="M0 0V-23.7L1200 36.564V60.264Z"/>
+    <path transform="matrix(1,0,0,-1,452.3481,0)" d="M0 0 747.652-253.794V-228.797L73.637 0Z"/>
+  </g>
+</svg>

assets/styles.css

@@ -289,12 +289,12 @@ address {
     position: fixed;
     z-index: 1;
     inset: 0 0 auto;
-    block-size: calc(254 * var(--unit));
+    block-size: calc(270 * var(--unit));
     background-image: var(--desktop-backdrop);
     background-size: 100% auto;
     background-repeat: no-repeat;
-    /* Reuse the original pixels, revealing only the opaque tape above content. */
-    mask-image: url("./construction-tape.svg");
+    /* Include the soft shadow above content without darkening the backdrop twice. */
+    mask-image: url("./construction-tape-mask.svg");
     mask-mode: alpha;
     mask-size: 100% auto;
     mask-repeat: no-repeat;