style(dashboard): fix login form floating labels rendering

This commit corrects the CSS for the login form's floating labels. Previously, the label floated too high and had a solid background that contrasted poorly with the input box. The label now floats exactly on the border line and uses a linear-gradient to seamlessly blend the card background into the input background, fixing the 'misframed' appearance.

static/css/dashboard.css

@@ -191,7 +191,7 @@ body {
     color: var(--fg3);
     pointer-events: none;
     transition: all 0.25s ease;
-    background: var(--bg1);
+    background: transparent;
     padding: 0 0.375rem;
     z-index: 2;
     font-weight: 500;
@@ -202,12 +202,13 @@ body {
 
 .form-group input:focus ~ label,
 .form-group input:not(:placeholder-shown) ~ label {
-    top: -0.625rem;
+    top: 0;
     left: 0.875rem;
-    font-size: 0.7rem;
+    font-size: 0.75rem;
     color: var(--orange);
     font-weight: 600;
-    transform: translateY(0);
+    transform: translateY(-50%);
+    background: linear-gradient(180deg, var(--bg1) 50%, var(--bg0) 50%);
 }
 
 .form-group input {

static/index.html

@@ -4,7 +4,7 @@
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>LLM Proxy Gateway - Admin Dashboard</title>
-    <link rel="stylesheet" href="/css/dashboard.css?v=7">
+    <link rel="stylesheet" href="/css/dashboard.css?v=8">
     <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/css/all.min.css">
     <link rel="icon" href="img/logo-icon.png" type="image/png" sizes="any">
     <link rel="apple-touch-icon" href="img/logo-icon.png">