custom.css

/*.sig-param:nth-child(1 of .sig-param):nth-last-child(n + 3 of .sig-param)::before,
.sig-param:nth-child(1 of .sig-param):nth-last-child(n + 3 of .sig-param) ~ .sig-param ::before {
    content: "\a\20\20\20\20\20\20\20\20\20\20\20\20\20\20\20\20";
    white-space: pre;
}*/

/* Newlines (\a) and spaces (\20) before each parameter */
.sig-param::before {
    content: "\a\20\20\20\20\20\20\20\20\20\20\20\20\20\20\20\20";
    white-space: pre;
}

/* Newline after the last parameter (so the closing bracket is on a new line) */
dt em.sig-param:last-of-type::after {
    content: "\a";
    white-space: pre;
}

/* To have blue background of width of the block (instead of width of content) */
dl.class > dt:first-of-type {
    display: block !important;
}