Apply CSS Variables to all message elements (#17920)

Fixes #17918. Applies color variables to all ui message on both themes.
The colorization on .segment is a customization not present in fomantic
ui, only used on user/repo/org delete pages.

web_src/less/_base.less

@@ -82,15 +82,18 @@
   --color-diff-moved-row-border: #d0e27f;
   --color-diff-added-row-border: #e6ffed;
   --color-diff-inactive: #f2f2f2;
-  --color-error-border: #c29393;
-  --color-error-bg: #fff5f5;
-  --color-error-text: #d64444;
+  --color-error-border: #e0b4b4;
+  --color-error-bg: #fff6f6;
+  --color-error-text: #9f3a38;
   --color-success-border: #a3c293;
   --color-success-bg: #fcfff5;
-  --color-success-text: #6cc644;
-  --color-warning-border: #c2c193;
-  --color-warning-bg: #fffff5;
-  --color-warning-text: #fbbd08;
+  --color-success-text: #2c662d;
+  --color-warning-border: #c9ba9b;
+  --color-warning-bg: #fffaf3;
+  --color-warning-text: #573a08;
+  --color-info-border: #a9d5de;
+  --color-info-bg: #f8ffff;
+  --color-info-text: #276f86;
   /* target-based colors */
   --color-body: #ffffff;
   --color-text-dark: #080808;
@@ -423,13 +426,68 @@ a.muted:hover,
 .ui.message {
   background: var(--color-box-body);
   color: var(--color-text);
-}
-
-.ui.bottom.attached.message {
   box-shadow: none !important;
   border: 1px solid var(--color-secondary);
 }
 
+.ui.info.message,
+.ui.attached.info.message,
+.ui.blue.message,
+.ui.attached.blue.message {
+  background: var(--color-info-bg);
+  color: var(--color-info-text);
+  border-color: var(--color-info-border);
+}
+
+.ui.success.message,
+.ui.attached.success.message,
+.ui.positive.message,
+.ui.attached.positive.message {
+  background: var(--color-success-bg);
+  color: var(--color-success-text);
+  border-color: var(--color-success-border);
+}
+
+.ui.error.message,
+.ui.attached.error.message,
+.ui.red.message,
+.ui.attached.red.message,
+.ui.negative.message,
+.ui.attached.negative.message {
+  background: var(--color-error-bg);
+  color: var(--color-error-text);
+  border-color: var(--color-error-border);
+}
+
+.ui.warning.message,
+.ui.attached.warning.message,
+.ui.yellow.message,
+.ui.attached.yellow.message {
+  background: var(--color-warning-bg);
+  color: var(--color-warning-text);
+  border-color: var(--color-warning-border);
+}
+
+.ui.error.header {
+  background: var(--color-error-bg) !important;
+  color: var(--color-error-text) !important;
+  border-color: var(--color-error-border) !important;
+}
+
+.ui.error.segment {
+  border-color: var(--color-error-border) !important;
+}
+
+.ui.warning.header {
+  background: var(--color-warning-bg) !important;
+  color: var(--color-warning-text) !important;
+  border-color: var(--color-warning-border) !important;
+}
+
+.ui.warning.segment {
+  border-color: var(--color-warning-border) !important;
+}
+
 .ui.selection.active.dropdown,
 .ui.selection.active.dropdown:hover,
 .ui.selection.active.dropdown .menu,
@@ -920,35 +978,9 @@ a.ui.card:hover,
     vertical-align: middle;
   }
 
-  .error {
-    &.header {
-      background-color: #ffe8e6 !important;
-      border-color: var(--color-red);
-    }
-
-    &.segment {
-      border-color: var(--color-red);
-    }
-  }
-
-  .warning {
-    &.header {
-      background-color: #f9edbe !important;
-      border-color: var(--color-yellow);
-    }
-
-    &.segment {
-      border-color: var(--color-yellow);
-    }
-  }
-
   .info {
     &.segment {
-      border: 1px solid #c5d5dd;
-
       &.top {
-        background-color: #e6f1f6 !important;
-
         h3,
         h4 {
           margin-top: 0;

web_src/less/themes/theme-arc-green.less

@@ -79,14 +79,17 @@
   --color-diff-added-row-border: #314a37;
   --color-diff-inactive: #353846;
   --color-error-border: #a53a37;
-  --color-error-bg: #403440;
-  --color-error-text: #d64444;
+  --color-error-bg: #482c2c;
+  --color-error-text: #ff4433;
   --color-success-border: #458a57;
-  --color-success-bg: #304440;
+  --color-success-bg: #284034;
   --color-success-text: #6cc664;
-  --color-warning-border: #aaa050;
-  --color-warning-bg: #404440;
+  --color-warning-border: #bb9d00;
+  --color-warning-bg: #3a3a30;
   --color-warning-text: #fbbd08;
+  --color-info-border: #306090;
+  --color-info-bg: #26354c;
+  --color-info-text: #38a8e8;
   /* target-based colors */
   --color-body: #383c4a;
   --color-box-header: #404652;
@@ -337,38 +340,6 @@ td.blob-hunk {
   color: #dbdbdb !important;
 }
 
-.ui .warning.header,
-.ui.warning.message {
-  background-color: #542 !important;
-  border-color: #ec8;
-}
-
-.ui.warning.message {
-  color: #ec8;
-  box-shadow: 0 0 0 1px #ec8;
-}
-
-.ui.warning.segment {
-  border-color: #ec8;
-}
-
-.ui.red.message,
-.ui.error.message {
-  background-color: #522;
-  color: #f9cbcb;
-  box-shadow: 0 0 0 1px #a04141 inset;
-}
-
-.ui .error.header,
-.ui.error.message {
-  background-color: #522 !important;
-  border-color: #a04141;
-}
-
-.ui.error.segment {
-  border-color: #a04141;
-}
-
 .ui.red.button,
 .ui.red.buttons .button {
   background-color: #7d3434;
@@ -379,18 +350,6 @@ td.blob-hunk {
   background-color: #984646;
 }
 
-.ui.positive.message {
-  background-color: #0d491b;
-  color: #87ab63;
-  box-shadow: 0 0 0 1px #2d693b inset, 0 0 0 0 transparent;
-}
-
-.ui.negative.message {
-  background-color: rgba(80, 23, 17, .6);
-  color: #f9cbcb;
-  box-shadow: 0 0 0 1px rgba(121, 71, 66, .5) inset, 0 0 0 0 transparent;
-}
-
 .ui.list .list > .item .header,
 .ui.list > .item .header {
   color: #dedede;