styles.css

body.format-multitopic ul.sections {
    list-style: none;
}

/* INCLUDED from theme/boost/style/moodle.css */
body.format-multitopic ul.sections li.section .content.collapse:not(.show) {
    display: none;
}
/* END INCLUDED */

/* ADDED */

/* Header */
body.format-multitopic .page-header-headings {
    display: none;
}
body.format-multitopic #course-header {
    width: 100%;
}

body.format-multitopic ul.sections li.section .sectionname .inplaceeditable {
    display: inline;
}

/* Hide activity navigation. */
body.format-multitopic.path-mod.pagelayout-incourse #page #page-content .activity-navigation {
    display: none;
}

/* END ADDED */