(#420) web: update styles of palette

MiniSpace.Web/src/Astravent.Web.Wasm/Pages/Account/SignIn.razor

@@ -14,7 +14,6 @@
 <style>
     body {
         margin: 0;
-        background: #f4f4f9;
     }
 
     .split-container {

MiniSpace.Web/src/Astravent.Web.Wasm/Pages/Feeds/UserInformation.razor

@@ -411,7 +411,7 @@
     .profile-paper {
         margin: 30px auto;
         max-width: 1200px;
-        background-color: #f7f9fc;
+        background-color: var(--mud-palette-surface);;
         border-radius: 12px;
         box-shadow: 0 6px 12px rgba(0, 0, 0, 0.1);
     }
@@ -455,7 +455,7 @@
     .modern-card {
         border-radius: 10px;
         box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
-        background-color: #ffffff;
+        background-color: var(--mud-palette-surface);
     }
 
     .icon-margin {
@@ -486,7 +486,7 @@
     .skill-interest-item {
         margin-right: 8px;
         margin-bottom: 8px; 
-        background-color: #f5f5f5; 
+        background-color: var(--mud-palette-secondary);
         padding: 2px 6px; 
         border-radius: 4px; 
         line-height: 1.2; /* Ensures good vertical spacing */

MiniSpace.Web/src/Astravent.Web.Wasm/wwwroot/css/site.css

@@ -292,7 +292,7 @@ html, body {
 
 .breadcrumbs-container {
     padding: 12px 24px;
-    background-color: #f9f9f9; 
+    background-color: var(--mud-palette-background-gray);
     border-radius: 5px; 
     box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
     margin: 20px 0 20px 0 !important; 
@@ -961,7 +961,7 @@ div.connectionRejected {
     justify-content: center;
     align-items: center;
     height: 100vh;
-    background-color: #ffffff;
+    /* background-color: #ffffff; */
     position: relative;
     transition: opacity 0.5s ease, visibility 0.5s ease;
 }