Revert "feat: add monochrome theme support (#4537)" (#4538)

This reverts commit bfc15e8141.

docs/.vitepress/theme/style.scss

@@ -138,13 +138,17 @@
 */
 :root {
   --vp-home-hero-name-color: transparent;
-  --vp-home-hero-name-background: -webkit-linear-gradient(120deg,
-      #c4b5fd 30%,
-      #7bc5e4);
+  --vp-home-hero-name-background: -webkit-linear-gradient(
+    120deg,
+    #c4b5fd 30%,
+    #7bc5e4
+  );
 
-  --vp-home-hero-image-background-image: linear-gradient(-45deg,
-      #c4b5fd 50%,
-      #47caff 50%);
+  --vp-home-hero-image-background-image: linear-gradient(
+    -45deg,
+    #c4b5fd 50%,
+    #47caff 50%
+  );
   --vp-home-hero-image-filter: blur(44px);
 }
 
@@ -219,7 +223,6 @@
     animation: nprogress-spinner 400ms linear infinite;
   }
 }
-
 .nprogress-custom-parent {
   overflow: hidden;
   position: relative;
@@ -250,7 +253,7 @@
   }
 }
 
-#VPContent strong>a {
+#VPContent strong > a {
   font-weight: bold;
 }
 
@@ -355,20 +358,4 @@
   mask-size: 100% 100%;
   background-color: currentColor;
   color: inherit;
-}
-
-/* Monochrome Specifics */
-html.monochrome {
-  filter: grayscale(100%);
-
-  img,
-  video,
-  iframe {
-    filter: grayscale(100%);
-  }
-
-  ::selection {
-    background-color: #333;
-    color: #fff;
-  }
 }