*{
    font-size: 100%;
}
body{
    width: 50%;
    margin: 0 auto;
    text-align: center;
    font-size: 1.75rem;
}
h1{
    font-size: 2.5rem;
    position: relative;
    display: inline-block;
    z-index: 10;
}
h1::before{
    content: '';
    height: 10px;
    width: 100%;
    background-color: aquamarine;
    position: absolute;
    bottom: 10px;
    left: 0;
    z-index: -10;
}
.start_btn{
    background-color:grey;
    color: white;
    border-radius: 5px;
    border: none;
    outline: none;
    cursor: pointer;
    padding: 5px;
}
.start_btn:hover{
    opacity: .7;
}

.clear{
    font-size: 1.75rem;
    background-color: rgb(0, 174, 255);
    color: white;
    display: inline-block;
    border-radius: 5px;
    border: none;
    outline: none;
    padding: 5px;
}
.answer{
    text-align: center;
    border: none;
    outline: none;
    border-bottom: 1px solid grey;
    margin-bottom: 20px;
}
.gage_wrapper{
    height: 12px;
    border: 1px solid grey;
}
.gage{
    height: 12px;
    transition: .5s;
}