feat: implement unauthorized error handling and login popup

public/src/components/LoginPanel.vue

@@ -45,7 +45,9 @@ async function attemptLogin() {
 <template>
 
     <div class="container">
+        <img src="./../assets/minis_logo.png" style="height: 80px"/>
         <span class="title">Anmelden</span>
+        <span class="subtitle">Um den Miniplan einsehen zu können, logge dich bitte ein.</span>
         <Input class="input" v-model:value="username" label="Nutzername"/>
         <Input class="input" v-model:value="password" label="Passwort" type="password"/>
         <span v-if="invalid" style="color: red; text-align: center; margin-bottom: 10px">Benutzername oder<br> Passwort falsch.</span>
@@ -69,11 +71,22 @@ async function attemptLogin() {
     .title{
         display: inline-block;
         font-size: 24px;
-        margin-bottom: 24px;
+        margin-bottom: 8px;
+        margin-top: 16px;
+    }
+
+    .subtitle {
+        margin-bottom: 30px;
+        max-width: 300px;
+        text-align: center;
+        opacity: 0.5;
+        font-style: italic;
+        line-height: 1.3rem;
     }
 
     .input {
         margin-bottom: 16px;
+        min-width: 300px;
     }
     button{
         margin-top: 8px;