The following custom CSS is used on both todon.eu and todon.nl (Public Domain, free to use). See also CSS snippets to can be used with Stylus.

/* Registration pages */

div.container-alt div.form-container div.simple_form ol.rules-list li:nth-child(16), div.about__section.active div.about__section__body ol.rules-list li:nth-child(16) {
display:none;
}

div.fields-group div.input.with_block_label.text.required.user_invite_request_text.field_with_hint label.text.required, div.fields-group div.input.with_block_label.text.required.user_invite_request_text.field_with_hint span.hint {
display: none;
}

.titlealt {
    font-size: 22px;
    line-height: 27px;
    font-weight: 50;
    margin-bottom: 10px;
}

/* Advanced UI */

@media (min-width: 701px) {

div.column {
        -webkit-box-flex:1 !important;
        -ms-flex-positive:1 !important;
        flex-grow: 1 !important;
}

.drawer__inner__mastodon {
	background: none !important;
}

}

/* Toot button */

a.button[href='/publish'],
.compose-form__publish-button-wrapper button.button.button--block,
.compose-form__actions .compose-form__submit button{
	display: flex;
	align-items: center;
	justify-content: center;
	font-size: 0;
}

a.button[href='/publish']::after,
.compose-form__publish-button-wrapper button::after,
.compose-form__actions .compose-form__submit button::after {
	content: 'Toot';
	font-size: 0.9rem;
}

/* Calm content warning  */

.content-warning::after, .content-warning::before {
  background: rgba(99,100,255,.15);
  border-left: 1px solid rgba(99,100,255,.15);
  border-right: 1px solid rgba(99,100,255,.15);
  border-end-start-radius: unset;
  border-start-start-radius: unset;  
  border-end-end-radius: unset;
  border-start-end-radius: unset;
}

.compose-form .spoiler-input__border {
      background: rgba(99,100,255,.15);
}

/* Down arrow Hide button */

.media-gallery__actions {
    inset-inline-end: 9px;
    top: 9px;    
}

.media-gallery__actions__pill {
    border-radius: 4px;
    padding: 3px 8px;
    line-height: 1 !important;
}

.media-gallery__actions__pill > span {
    font-size: 0
}

.media-gallery__actions__pill > span::after {
    	content: '⛛';
    	font-size: 12px;
}

/* Misc */

.modal-layout__mastodon > div > img {
    display: none;
}

img.announcements__mastodon {
    display: none;
}