improve confusing login experience

src/components/Login.vue

@@ -43,9 +43,8 @@
         ></v-text-field>
 
         <div class="text-red" v-if="loadingLoginFlows">Loading login flows...</div>
-
         <v-text-field
-          v-show="showPasswordField"
+          :disabled="!user.user_id || !showPasswordField"
           prepend-inner-icon="$vuetify.icons.password"
           ref="password"
           v-model="user.password"