.question {
    display: inline-block;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background-color: #ccc;
    color: white;
    text-align: center;
    line-height: 16px;
    font-size: 12px;
    margin-left: 5px;
    cursor: pointer;
    position: relative;
}

.question:hover:after {
    content: attr(title);
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    bottom: 20px;
    background-color: #333;
    color: white;
    padding: 5px 10px;
    border-radius: 5px;
    white-space: nowrap;
    z-index: 10;
}