Every input needs a <label for="id"> (not just placeholder text) so screen readers announce the field name and clicking the label focuses the input. autocomplete="email" and autocomplete="current-password" give the browser and password manager the right hints, which is what triggers autofill and one-tap login. The type="email" activates email-style mobile keyboards and basic format validation; minlength="8" adds a server-side-friendly client check. These tiny attributes make the difference between a clunky and a polished login.

aria-describedby links the input to one or more help-text and error elements. Screen readers read those messages right after the field name, which is what makes inline validation accessible. aria-invalid="true" flips the field into an error state for assistive tech, and role="alert" on the error container pushes the message to a live region so updates are announced. The combination is what good error UX looks like on every form: the message is visible, programmatically associated, and announced when it changes.

<fieldset> plus <legend> is the right wrapper for groups of related inputs (an address, a credit card, a set of radio buttons). Screen readers announce the legend before each child input, which gives blind users the same context that sighted users get from a heading. Grouping radio buttons inside a single fieldset is mandatory for accessibility, since the legend tells the user what the group is choosing between. The inputmode="numeric" plus autocomplete="postal-code" combination unlocks the right mobile keyboard and the saved postal code on the user's device.