style: 增加样式

Author: ArgoZhang

src/components/BootstrapBlazor.PdfReader/wwwroot/css/pdf_viewer.css

@@ -153,3 +153,19 @@
     margin: 0 auto;
     border: 2px solid transparent;
 }
+
+.textLayer {
+    position: absolute;
+    text-align: initial;
+    inset: 0;
+    overflow: clip;
+    opacity: 1;
+    line-height: 1;
+    -webkit-text-size-adjust: none;
+    -moz-text-size-adjust: none;
+    text-size-adjust: none;
+    forced-color-adjust: none;
+    transform-origin: 0 0;
+    caret-color: CanvasText;
+    z-index: 0;
+}