UI refinements (#2859)

## Description:

UI Refinements requested by @evanpelle  check https://ui.openfront.dev

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

w.o.n

src/client/JoinPrivateLobbyModal.ts

@@ -38,7 +38,7 @@ export class JoinPrivateLobbyModal extends BaseModal {
   render() {
     const content = html`
       <div
-        class="h-full flex flex-col bg-black/40 backdrop-blur-md rounded-2xl border border-white/10 overflow-hidden select-none"
+        class="h-full flex flex-col bg-black/60 backdrop-blur-md rounded-2xl border border-white/10 overflow-hidden select-none"
       >
         <div
           class="flex items-center mb-6 pb-2 border-b border-white/10 gap-2 shrink-0 p-6"
@@ -137,6 +137,25 @@ export class JoinPrivateLobbyModal extends BaseModal {
                       ? this.currentLobbyId
                       : "••••••••"}
                 </div>
+                <button
+                  @click=${this.copyToClipboard}
+                  class="p-1.5 rounded-md hover:bg-white/10 text-white/60 hover:text-white transition-colors"
+                  title="${translateText("common.click_to_copy")}"
+                  aria-label="${translateText("common.click_to_copy")}"
+                  type="button"
+                >
+                  <svg
+                    viewBox="0 0 24 24"
+                    height="16px"
+                    width="16px"
+                    fill="currentColor"
+                    aria-hidden="true"
+                  >
+                    <path
+                      d="M16 1H4c-1.1 0-2 .9-2 2v12h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"
+                    />
+                  </svg>
+                </button>
               </div>`
             : ""}
         </div>