.titre {
    margin-top: -60px;
    margin-bottom: 0px;
}

.fraction , .noyau {
	display: inline-block;
	position: relative;
	vertical-align: middle; 
	letter-spacing: 0.01em;
	text-align: center;
	}
.fraction .num , .fraction .denom , .noyau > * { 
	display: block; 
	padding: 0.2em; 
	}
.fraction .denom {border-top: thin solid black;}



    .c_s {background-color: #6F6 !important} /* stable */
    .c_i {background-color: #D8D !important} /* instable */
    .c_p {background-color: #66F !important} /* émetteur bêta+ */        
    .c_e {background-color: #F88 !important} /* émetteur bêta- */               
    .c_a {background-color: #ED0 !important} /* émetteur alpha */  



    #aff {
        margin: 40px;
        font-size: larger;
        border:  solid 1px #888;
        border-radius:10px;
        padding: 10px;
        display: inline-block;
        background-color: #6A6;
        color:white;
       /* font-weight: 600; */
        width: 110px;
        height: 110px;
        position: absolute;
        top:130px;
        left:0px;
        font-family:arial;
        text-align:center;
    }
    
    .symb {
        position:relative;
        top:6px;
        font-size:22px;
    }

    #Segre {
        width:720px;
        height: 460px;
   }
    
    #Segre span {
        position:absolute;
        width:4px;
        height: 4px;
    }
    #Segre span:hover,.selectionne {
     /*   border: solid 1px #444;  */
        stroke:#444;
        z-index: 100;
    }
    
    
    #Segre rect:hover {
        stroke:#444;
        z-index: 100;
    }    
    
    
  
    
    #aide__ {
        position:absolute;
        top:300px;
        left:300px;
        width:300px;
        color:white;
        background-color: rgba(200,200,150,0.8);
        border:solid rgba(200,200,150,0.3);
        border-radius: 4px;
        padding: 4px;
        opacity:0.0; 
        transition: opacity 0.5s;
        z-index:-1;
    }
    #aide_i {
        position:absolute;
        top:400px;
        left:380px;        
        transition: opacity 0.5s;
    }

   
    
    
    #Emilio_Segre {
        display:flex;
        align-items: center; 
        justify-content: space-evenly;
        font-size:9px;
        border:solid 1px #A88;
        border-radius:4px;
        color: #A88;
        background-color: rgba(200,100,100,0.1);
        padding:4px;
        text-align:justify;
        margin: 4px;
        width: 300px;
    }
    #Emilio_Segre span {
        display:inline-block;
        width:200px;
    }
    #instruction {
        font-weigth:normal;
        font-size:smaller;
    }
    #isotope {
        font-family:verdana;
    }
    .entete {
        display:flex;
        align-items: center; 
        justify-content: space-evenly;
        width: 520px;
        position:absolute;
        left:20px;
        top:20px; 
    }
    .menu {
        color:#400;
        width:auto;
        height:auto;
        font-size:11px;
        padding:4px;
        text-align:center;
    }