The main problem with HTML input boxes that don’t have a border is that they can look sloppy and unprofessional.
<input type="text" style="border:0;">
The code line creates an input element of type text, and sets the border style to 0.
Parts of Box Model
The box model is a layout model in HTML that defines how content is laid out within a document. The box model consists of four main parts: the body, the header, the footer, and the section.