/*
https://www.w3schools.com/howto/howto_css_tooltip.asp

or try 

https://www.w3schools.com/bootstrap/bootstrap_ref_js_tooltip.asp
(this one would be a js with jquery)

*/

.tooltip {
    position: relative;
    display: inline-block;
    border-bottom: 1px dotted black;
}

.tooltip .tooltiptext {
    visibility: hidden;
    width: 120px;
    background-color: #555;
    color: #fff;
    text-align: center;
    border-radius: 6px;
    padding: 5px 0;
    position: absolute;
    z-index: 1;
    bottom: 125%;
    left: 50%;
    margin-left: -60px;
    opacity: 0;
    transition: opacity 0.3s;
}

.tooltip .tooltiptext::after {
    content: "";
    position: absolute;
    top: 100%;
    left: 50%;
    margin-left: -5px;
    border-width: 5px;
    border-style: solid;
    border-color: #555 transparent transparent transparent;
}

.tooltip:hover .tooltiptext {
    visibility: visible;
    opacity: 1;
}

/*
https://stackoverflow.com/questions/20996228/trying-to-create-a-consistent-mark-inside-circle-in-css
this is for making '?' in circle
*/
.infolink::before
{
    content: '?';
    font-size: 60%;
    font-family: sans-serif;
    vertical-align: middle;
    font-weight: bold;
    text-align: center;
    display: inline-block;
    width: 1.8ex;
    height: 1.8ex;
    border-radius: 1ex;
    color: blue;
    background: white;
    border: thin solid blue;
    
    line-height:1.8ex;
}