pre.question-sql code {
    display: block;
    padding: 0.5rem;
    background-color: #F0F0F0;
}
pre.question-sql {
    display: none;
}
input.question-sql {
    display: none;
}
input:checked.question-sql ~ pre {
    display: block;
}
div.question-sql {
    border: 1px solid lightgray;
    border-radius: 0.5rem;
    padding: 0.5rem;
    margin: 0.5rem;
}
label.question-sql {
    background-color: #e7e7e7;
    box-shadow: inset 0 2px 3px rgba(255,255,255,0.2), inset 0 -2px 3px rgba(0,0,0,0.2);
    border-radius: 4px;
    display: inline-block;
    padding: 2px 5px;
    cursor: pointer;
}
input + label.question-sql:after {
    content: "zobraziť riešenie"; 
}
input:checked + label.question-sql:after {
    content: "skyť riešenie"; 
}