MapComplete/css/fullscreenmessagebox.css

.fullscreenmessage-content {
    max-height: calc(100vh - var(--return-to-the-map-height));
    height: 100%;
    overflow-y: auto;
    overflow-x: hidden;
    background-color: var(--background-color);
    display: block;
}

.fullscreenmessage-content .featureinfobox {
    padding-top: 1em;
    position: relative;
}

.fullscreenmessage-content .featureinfobox-content {
    padding: 1em;
    top: var(--variable-title-height);
    /* 2em extra: padding from the title */
    max-height: calc(100vh - var(--variable-title-height) - var(--return-to-the-map-height) - 2em) !important;
    display: block;
    position: absolute;
    overflow-y: auto;
}

.fullscreenmessage-content .featureinfobox-titlebar {
    position: fixed;
    top: 0;
    left: 0;
    z-index: 10001;
    background-color: var(--background-color);
    padding: 0.5em;
    width: 100%;
    box-sizing: border-box;
 
}

.fullscreenmessage-content .featureinfobox-tail {
    display: block;
    height: 1em;
}


.to-the-map span {
    font-size: xx-large;
}

.to-the-map {
    background: var(--catch-detail-color);
    height: var(--return-to-the-map-height);
    position: fixed;
    z-index: 10000;
    bottom: 0;
    left: 0;
    width: 100vw;
    color: var(--catch-detail-color-contrast);
    font-weight: bold;
    pointer-events: all;
    cursor: pointer;
    padding-top: 1.2em;
    text-align: center;
    padding-bottom: 1.2em;
    box-sizing: border-box;
}