Add Language Selector component to footer

Introduced a Language Selector component (`LanguageSelector.razor`) to enable users to switch between German, English, and French. The component includes a dropdown UI with flag icons and language labels, along with logic for toggling the dropdown and changing the app's culture.

Injected `IJSRuntime`, `NavigationManager`, and `CultureService` into the component to handle culture changes and navigation updates.

Updated `MainLayout.razor` to include the Language Selector in the footer. Refactored footer layout in `MainLayout.razor.css` to use flexbox for better alignment and spacing.

Added styles for the Language Selector in `app.css` to ensure a clean and responsive design. Integrated the `flag-icons` library in `index.html` to display flag icons for language representation.

EnvelopeGenerator.ReceiverUI/Shared/LanguageSelector.razor

@@ -0,0 +1,62 @@
+@using System.Globalization
+@using EnvelopeGenerator.ReceiverUI.Services
+@inject IJSRuntime JSRuntime
+@inject NavigationManager Navigation
+@inject CultureService CultureService
+
+<div class="language-selector">
+    <button class="language-selector__trigger" @onclick="ToggleDropdown" aria-label="Select Language">
+        <span class="fi fi-@GetFlagCode(CurrentCulture)"></span>
+        <span class="language-selector__arrow">?</span>
+    </button>
+    
+    @if (isOpen)
+    {
+        <div class="language-selector__dropdown">
+            <button class="language-selector__option" @onclick="@(() => ChangeLanguageAsync("de-DE"))">
+                <span class="fi fi-de"></span>
+                <span>Deutsch</span>
+            </button>
+            <button class="language-selector__option" @onclick="@(() => ChangeLanguageAsync("en-US"))">
+                <span class="fi fi-us"></span>
+                <span>English</span>
+            </button>
+            <button class="language-selector__option" @onclick="@(() => ChangeLanguageAsync("fr-FR"))">
+                <span class="fi fi-fr"></span>
+                <span>Français</span>
+            </button>
+        </div>
+    }
+</div>
+
+@code {
+    private bool isOpen = false;
+    private string CurrentCulture => CultureInfo.CurrentCulture.Name;
+
+    private void ToggleDropdown()
+    {
+        isOpen = !isOpen;
+    }
+
+    private async Task ChangeLanguageAsync(string culture)
+    {
+        if (CultureInfo.CurrentCulture.Name != culture)
+        {
+            await CultureService.SetCultureAsync(culture);
+            Navigation.NavigateTo(Navigation.Uri, forceLoad: true);
+        }
+        
+        isOpen = false;
+    }
+
+    private string GetFlagCode(string culture)
+    {
+        return culture switch
+        {
+            "de-DE" => "de",
+            "en-US" => "us",
+            "fr-FR" => "fr",
+            _ => "de"
+        };
+    }
+}

EnvelopeGenerator.ReceiverUI/Shared/MainLayout.razor

@@ -8,9 +8,12 @@
         </article>
     </main>
     <footer class="receiver-footer">
-        <span>&copy; SignFlow 2023-2024 <a href="https://digitaldata.works" target="_blank" rel="noopener">Digital Data GmbH</a></span>
+        <div class="receiver-footer__content">
-        <span class="receiver-footer__sep">&#124;</span>
+            <span>&copy; SignFlow 2023-2024 <a href="https://digitaldata.works" target="_blank" rel="noopener">Digital Data GmbH</a></span>
-        <a href="docs/privacy-policy.de-DE.html" target="_blank" rel="noopener">Datenschutz</a>
+            <span class="receiver-footer__sep">&#124;</span>
+            <a href="docs/privacy-policy.de-DE.html" target="_blank" rel="noopener">Datenschutz</a>
+        </div>
+        <LanguageSelector />
     </footer>
 </div>
 

EnvelopeGenerator.ReceiverUI/Shared/MainLayout.razor.css

@@ -15,3 +15,18 @@ article {
     padding: 0 !important;
     margin: 0 !important;
 }
+
+.receiver-footer {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    padding: 1rem 2rem;
+    gap: 1rem;
+}
+
+.receiver-footer__content {
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+}
+

EnvelopeGenerator.ReceiverUI/wwwroot/css/app.css

@@ -366,3 +366,74 @@ article {
 .receiver-footer__sep {
     opacity: 0.4;
 }
+
+/* ── Language Selector (Footer) ──────────────────────────────────────────── */
+.language-selector {
+    position: relative;
+    display: inline-block;
+}
+
+.language-selector__trigger {
+    display: flex;
+    align-items: center;
+    gap: 0.4rem;
+    padding: 0.25rem 0.5rem;
+    background: rgba(255, 255, 255, 0.1);
+    border: 1px solid rgba(255, 255, 255, 0.2);
+    border-radius: 4px;
+    color: rgba(255, 255, 255, 0.9);
+    cursor: pointer;
+    font-size: 1rem;
+    transition: all 0.2s ease;
+}
+
+.language-selector__trigger:hover {
+    background: rgba(255, 255, 255, 0.15);
+    border-color: rgba(255, 255, 255, 0.3);
+}
+
+.language-selector__arrow {
+    font-size: 0.6rem;
+    transition: transform 0.2s ease;
+    opacity: 0.7;
+}
+
+.language-selector__dropdown {
+    position: absolute;
+    bottom: calc(100% + 0.5rem);
+    right: 0;
+    background: white;
+    border: 1px solid #ddd;
+    border-radius: 6px;
+    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
+    min-width: 160px;
+    z-index: 1000;
+    overflow: hidden;
+}
+
+.language-selector__option {
+    display: flex;
+    align-items: center;
+    gap: 0.75rem;
+    width: 100%;
+    padding: 0.65rem 1rem;
+    background: white;
+    border: none;
+    color: #333;
+    cursor: pointer;
+    font-size: 0.9rem;
+    transition: background-color 0.2s ease;
+    text-align: left;
+}
+
+.language-selector__option:hover {
+    background-color: #f5f5f5;
+}
+
+.language-selector__option .fi {
+    font-size: 1.25rem;
+}
+
+.language-selector__option span:last-child {
+    font-weight: 500;
+}

EnvelopeGenerator.ReceiverUI/wwwroot/index.html

@@ -12,6 +12,7 @@
     <link href="css/bootstrap/bootstrap.min.css" rel="stylesheet" />
     <link href="EnvelopeGenerator.ReceiverUI.styles.css" rel="stylesheet" />
     <link href="css/app.css" rel="stylesheet" />
+    <link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/lipis/flag-icons@7.2.3/css/flag-icons.min.css" />
     <style type="text/css">
         .splash-screen {
             display: flex;