refactor: 增加样式

Author: ArgoZhang

src/components/BootstrapBlazor.Region/Components/SelectCity.razor.cs

@@ -17,14 +17,14 @@ public partial class SelectCity
 
     private string? InputId => $"{Id}_input";
 
-    private string? ClassString => CssBuilder.Default("select bb-region")
+    private string? ClassString => CssBuilder.Default("select bb-city")
         .AddClass("disabled", IsDisabled)
         .AddClassFromAttributes(AdditionalAttributes)
         .Build();
 
     private readonly HashSet<string> _values = [];
 
-    private string? GetActiveClass(string item) => _values.Contains(item) ? "active" : null;
+    private string? GetActiveClass(string item) => _values.Contains(item) || CurrentValue == item ? "active" : null;
 
     private async Task OnClearValue()
     {

src/components/BootstrapBlazor.Region/Components/SelectCity.razor.css

@@ -1,4 +1,12 @@
-.dropdown-menu {
+.bb-city {
+    position: relative;
+}
+
+    .bb-city:not(.disabled):hover .form-select-append {
+        display: none;
+    }
+
+.dropdown-menu {
     --bs-dropdown-padding-y: .5rem;
     --bs-dropdown-padding-x: .5rem;
     max-width: 400px;