header {
    background-image: linear-gradient(to left, #a1cbef, #2176bd);
    padding: 1.5em 2em;
}

a{
    text-decoration: none;
    color: white;
}

a:hover{
    text-decoration: underline;
}

nav > a{
    padding-right: 25px;
    paddding-left: 25px;
    text-transform: uppercase;
    color: rgba(255,255,255, .8);

}

div.bar {
    display: inline-block;
    width: 20px;
    height: 75px;
    background-color: teal;
}

.button {

    border-width: 2px ;
    border-color: gray;
    color: black;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    padding: 5px;
    box-shadow: 2px 2px 2px 2px rgba(0,0,0,0.2)
}

.button:active{
    background-color: lightgray;
}


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

.tooltip .tooltiptext {
    visibility: hidden;
    width: 180px;
    background-color: rgba(108, 122, 137, 0.3);
    color: black;
    text-align: center;
    border-radius: 6px;
    padding: 8px 0;

    top: 100%;
    left: 50%;
    margin-left: -60px; /* Use half of the width (120/2 = 60), to center the tooltip */

    /* Position the tooltip */
    position: absolute;
    z-index: 1;
}

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