Change default login background to cloud image

Signed-off-by: Carl Schwan <carl@carlschwan.eu>

apps/theming/css/settings-admin.css

@@ -90,7 +90,7 @@
   margin-bottom: 20px;
   cursor: pointer;
   background-color: var(--color-primary);
-  background-image: var(--image-background, var(--image-background-plain, url("../../../core/img/background.svg"), linear-gradient(40deg, #0082c9 0%, #30b6ff 100%)));
+  background-image: var(--image-background, var(--image-background-plain, url("../../../core/img/app-background.jpg"), linear-gradient(40deg, #0082c9 0%, #30b6ff 100%)));
 }
 #theming #theming-preview #theming-preview-logo {
   cursor: pointer;

apps/theming/css/settings-admin.scss

@@ -101,7 +101,7 @@
         margin-bottom: 20px;
         cursor: pointer;
         background-color: var(--color-primary);
-        background-image: var(--image-background, var(--image-background-plain, url('../../../core/img/background.svg'), linear-gradient(40deg, #0082c9 0%, #30b6ff 100%)));
+        background-image: var(--image-background, var(--image-background-plain, url('../../../core/img/app-background.jpg'), linear-gradient(40deg, #0082c9 0%, #30b6ff 100%)));
 
         #theming-preview-logo {
             cursor: pointer;

core/css/guest.css

@@ -21,14 +21,11 @@ body {
 	font-size: .875em;
 	line-height: 1.6em;
 	font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen-Sans, Ubuntu, Cantarell, 'Helvetica Neue', Arial, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';
-	color: var(--color-primary-text);
+	color: var(--color-text);
 	text-align: center;
 	background-color: var(--color-primary);
-	background-image: var(--image-background, var(--image-background-plain, url('../../../core/img/background.svg'), linear-gradient(40deg, #0082c9 0%, #30b6ff 100%)));
-	background-position: 50% 50%;
-	background-repeat: repeat;
-	background-size: var(--image-background-size, 275px, contain);
-	background-attachment: fixed; /* fix background gradient */
+	background-image: var(--image-background, var(--image-background-plain, url('../../../core/img/app-background.jpg'), linear-gradient(40deg, #0082c9 0%, #30b6ff 100%)));
+    background-attachment: fixed;
 	min-height: 100%; /* fix sticky footer */
 	height: auto;
 	overflow: auto;
@@ -40,7 +37,7 @@ body {
 	font-weight: 600;
 }
 #body-login footer a {
-    color: var(--color-primary-text);
+    color: var(--color-text);
 }
 #body-login a:not(.button):hover,
 #body-login a:not(.button):focus {