#roll_dice {
    width: 40px;
    height: 40px;
    margin: 0;
    padding: 1px;
    background: no-repeat;
    background-size: 26px auto;
    background-position: center center;
    outline: none;
    border: none;
    cursor: pointer;
    transition: 0.3s;
    filter: invert(1);
    opacity: 0.5;
}

#roll_dice:hover {
    opacity: 1;
}

.list-group {
    display: flex;
    flex-direction: column;
    padding-left: 0;
    margin-top: 0;
    margin-bottom: 3px;
}

.list-group-item {
    position: relative;
    display: block;
    padding: 0.75rem 1.25rem;
    margin-bottom: -1px;
    background-color: rgba(0,0,0,0.3);
    border: 1px solid rgba(0,0,0,0.7);
    box-sizing: border-box;
    user-select: none;
    cursor: pointer;
}