.materials {
    padding: 20px;
    font-size: 1rem;
    line-height: 1.45;
    min-height: 50vh;
    margin-bottom: 25vh;
}

#id_material span {
    cursor: pointer;
    display: inline-block;
    padding: 0 2px;
    transition: background-color 0.2s;
}

#id_material span:hover {
    background-color: #e0e0e0;
    border-radius: 4px;
}

.options {
    position: fixed;
    /* Keep it fixed to the screen */
    bottom: 0;
    /* Align to the very bottom */
    left: 0;
    width: 100%;
    height: 25vh;
    background-color: white;
    border-top: 2px solid #333;
    z-index: 2000;
    /* Increase this to be sure it's on top */
    display: flex;
    /* Needed for alignment if not using BS5 classes */
    align-items: center;
    justify-content: center;
}