When the action buttons are too wide, it causes the text box to be that wide, since the `Input` has `Layout.fillWidth: true` set, causing the text to overflow the background. This change makes the background expand with the text.
The login button now fills the parent width, since when the ActionButtons are too large and overflow the fixed 270, it causes the inputs to be as wide as them but not the button, so this change should make the button match the inputs in such cases.
Having a disabled login button with almost transparent text makes it hard to read, thus not as aesthetic as a clearer label. IMHO transparent text is not that good an indicator that the button is unclickable. Besides, everyone knows that they have to enter a password before they log in, as is evident by the password input, and by the fact that they created a password.
