fix(iframe): background was white in tomorrow theme

src/app.module.css

@@ -1,5 +1,6 @@
 .app {
   z-index: 1;
+  color-scheme: var(--color-scheme, revert) !important;
 }
 
 .boardLayout {

src/components/comment-media/comment-media.module.css

@@ -88,6 +88,7 @@
 
 .content iframe {
   border: none;
+  color-scheme: light;
 }
 
 .fileInfo {

src/index.css

@@ -30,8 +30,8 @@ hr {
   text-transform: capitalize;
 }
 
-* {
-  color-scheme: var(--color-scheme, revert);
+:root {
+  color-scheme: dark;
 }
 
 @media (max-width: 640px) {

src/themes.css

@@ -1,4 +1,6 @@
 :root .yotsuba {
+  --color-scheme: light;
+  
   /* backlink */
   --post-backlink-text-color: navy;
   --post-backlink-text-decoration: underline;
@@ -204,6 +206,8 @@
 }
 
 :root .yotsuba-b {
+  --color-scheme: light;
+  
   /* backlink */
   --post-backlink-text-color: #34345C;
   --post-backlink-text-decoration: underline;
@@ -409,6 +413,8 @@
 }
 
 :root .futaba {
+  --color-scheme: light;
+
   /* backlink */
   --post-backlink-text-color: navy;
   --post-backlink-text-decoration: underline;
@@ -581,6 +587,8 @@
 }
 
 :root .burichan {
+  --color-scheme: light;
+  
   /* backlink */
   --post-backlink-text-color: #34345C;
   --post-backlink-text-decoration: underline;
@@ -976,6 +984,8 @@
 }
 
 :root .photon {
+  --color-scheme: light;
+  
   /* backlink */
   --post-backlink-text-color: #f60;
   --post-backlink-text-decoration: underline;