.signal {
    display: inline-block;
margin-bottom: 0.8em; 
margin-right: 1em;
    vertical-align: top;
    text-align: center;    
}

.signal svg {
    display: block;
    cursor: pointer;
margin-bottom: 0.5em;
}

.signal .signal-curve{ 
 stroke: blue; stroke-width: 2px; fill: blue; fill-opacity: 0.3
}

.signal.wrong .signal-curve{ 
 stroke: red; fill: red; 
}

.signal.correct .signal-curve{ 
 stroke: darkgreen; fill: green; 
}
.signal .signal-solution {
fill: none; stroke: darkgreen; stroke-width: 2px; stroke-dasharray: 5 5;
}

.signal .result {
   display: none
}