Template:Update history navbox/styles.css

.bc-version-year > .mw-collapsible-toggle {
    float: none;
    display: block;
    position: static;
    text-align: center;
    margin: 0.5em auto;
}
.bc-version-year > .mw-collapsible-content > .wikitable {
    margin-top: 0;
}