feat(login): redesign login page with split layout

src/styles/layout.scss

@@ -407,98 +407,6 @@
   }
 }
 
-.login-page {
-  min-height: 100vh;
-  display: flex;
-  align-items: center;
-  justify-content: center;
-  background: var(--bg-secondary);
-  padding: $spacing-lg;
-
-  .login-card {
-    width: 100%;
-    max-width: 520px;
-    background: var(--bg-primary);
-    border: 1px solid var(--border-color);
-    border-radius: $radius-lg;
-    box-shadow: var(--shadow-lg);
-    padding: $spacing-xl;
-    display: flex;
-    flex-direction: column;
-    gap: $spacing-lg;
-  }
-
-  .login-header {
-    display: flex;
-    flex-direction: column;
-    gap: $spacing-sm;
-    text-align: center;
-
-    .title {
-      font-size: 22px;
-      font-weight: 800;
-      color: var(--text-primary);
-    }
-
-    .subtitle {
-      color: var(--text-secondary);
-    }
-  }
-
-  .login-title-row {
-    display: flex;
-    align-items: center;
-    justify-content: center;
-    gap: $spacing-sm;
-    flex-wrap: wrap;
-  }
-
-  .login-language-btn {
-    white-space: nowrap;
-  }
-
-  .connection-box {
-    background: var(--bg-secondary);
-    border: 1px dashed var(--border-color);
-    border-radius: $radius-md;
-    padding: $spacing-md;
-    display: flex;
-    flex-direction: column;
-    gap: $spacing-xs;
-
-    .label {
-      color: var(--text-secondary);
-      font-size: 14px;
-    }
-
-    .value {
-      font-weight: 700;
-      color: var(--text-primary);
-    }
-
-    .item-actions {
-      display: flex;
-      gap: $spacing-md;
-    }
-  }
-
-  .toggle-advanced {
-    display: flex;
-    justify-content: flex-start;
-    align-items: center;
-    gap: $spacing-xs;
-    color: var(--text-secondary);
-    cursor: pointer;
-  }
-
-  .error-box {
-    background: rgba(239, 68, 68, 0.1);
-    border: 1px solid rgba(239, 68, 68, 0.4);
-    border-radius: $radius-md;
-    padding: $spacing-sm $spacing-md;
-    color: $error-color;
-  }
-}
 
 .grid {
   display: grid;