espocrm-base/frontend/less/espo/main.less

@import "bootstrap/bootstrap.less";
@import "variables.less";
@import "mixins.less";

@import "misc.less";
@import "layout.less";
@import "custom.less";

@import "../espo/mixins/side-modal.less";

@import "bootstrap/utilities.less";

body {
    --theme-name: Espo;
}