Code to remove the headers and footers from a page. Put code in the Divi Builder custom CSS for this page only. Not in the customs CSS for whole site.

/* Hide the header */

#secondary-menu { display:none; }

#main-header { display:none; }

#page-container {

padding-top:0px !important;

margin-top:-1px !important

}

#top-header {

display: none;

}

/* Adjust padding for transparent headers */

.et_transparent_nav #main-content .container {

padding-top: 58px !important;

}

/*Hide the Divi Footer*/
#main-footer {
display: none;
}