.solve-form {
    background-color: var(--grey-100);
    padding: 1em;
    padding-bottom: 3em; /* add 2 em to fit the button */
    border-radius: 0.25em;
    height: calc(100% + 2em);
}

.solve-form label {
    display: block;
    margin: 1em 0;
    cursor: pointer;
}

.solve-form select {
    width: 100%;
    cursor: pointer;
}

.solve-form label > * {
    margin-top: 0.25em;
}

#solveBtn {
    float: right;
}