.block--json .copy-btn {
    position: absolute;
    top: 0;
    right: 0;
    padding: 2px 8px;
    margin: 0;
    font-size: 12px;
    cursor: pointer;
    z-index: 2;
    opacity: 0;
    transition-property: opacity;
    transition-duration: 0.5s;
    transition-delay: 0s;
}
.block--json:hover .copy-btn {
    opacity: 1;
}

.block--json .copy-pre {
    white-space: pre-wrap;
    margin: 0;
    max-height: 300px;
    overflow: auto;
}
.block--json:hover .copy-pre {
    height: auto;
}

.block--json {
    position:relative;
    /*max-width:700px;*/
}