Style complexity progress bars more heavily

This disables the native progress appearance and uses the green color from our
themes.

res/css/views/auth/_AuthBody.scss

@@ -133,4 +133,24 @@ limitations under the License.
 
 .mx_AuthBody_passwordScore {
     width: 100%;
+    appearance: none;
+    height: 4px;
+    border: 0;
+    border-radius: 2px;
+    position: absolute;
+    top: -12px;
+
+    &::-moz-progress-bar {
+        border-radius: 2px;
+        background-color: $accent-color;
+    }
+
+    &::-webkit-progress-bar,
+    &::-webkit-progress-value {
+        border-radius: 2px;
+    }
+
+    &::-webkit-progress-value {
+        background-color: $accent-color;
+    }
 }

res/css/views/elements/_Validation.scss

@@ -14,6 +14,10 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+.mx_Validation {
+    position: relative;
+}
+
 .mx_Validation_details {
     padding-left: 20px;
     margin: 0;