#cuerpo {width: 100%;
        background: #33FFFF;
        font-size: 23px;
}
article {color: #000000;
    display: inline-block;
    margin: -50px 100px;
    font-size: 28px;
}
#Explicación { text-align: center;
            width: 87%;
            height: 50px;
            display: inline-block;
            border: 2px solid #9933FF;
            color: #FF0033;
 }
#Actividad { text-align: left;
            width: 87%;
            height: 850px;
            display: block;
            border: 2px solid #9933FF;
 }
 #columna {width: 14%;
    height: 503px;
    text-align: center;
    display: inline-block;
    float: right;
}
#Comprobar {
  border-radius: 10px;
    padding-bottom: initial;
    color: #FFFFFF;
    background-color: #9933FF;
    width: 100px;
    height: 50px;
    margin: 30px 0px;
    font-size: 14px;  
    float: right;
    margin-right: 20px;
    margin-top: 100px;
}#berriro{
    border-radius: 10px;
    padding-bottom: initial;
    color: #FFFFFF;
    background-color: #9933FF;
    width: 100px;
    height: 50px;
    margin: 30px 0px;
    font-size: 14px;  
    float: right;
    margin-right: 20px;
    margin-top: 50px;
    display: none;
}
#cabecera {background: #FFCCFF;
        padding: 10px;
        width: 98.5%;
        height: 100px;
        border: 3px solid #9933FF;
}
img {width: 60px;
    display: inline-block;
}
.caja{color: red;
        width: 300px;
        height: 60px;
        font-size: 50px;
        text-align: center;
        margin-top: 40px;
        margin-left: 50px;
}.texto{
        color: blue;
        font-size: 60px;
        margin-top: 30px;
        margin-left: 10px;
}#texto12{
        color: blue;
        font-size: 70px;
}#Principal {
  border-radius: 10px;
    padding-bottom: initial;
    color: #000000;
    background-color: lightgrey;
    width: 100px;
    height: 50px;
    margin: 25px 0px;
    font-size: 14px;  
    float: right;
    margin-right: 20px;
    margin-top: 10px;
}#Principal:hover{ 
        cursor:pointer
}#Siguiente { 
    border-radius: 10px;
    padding-bottom: initial;
    color: #0033FF;
    background-color: FFFFFF;
    width: 120px;
    height: 100px;
    margin: 25px 0px;
    font-size: 25px;
}#Siguiente:hover{ 
        cursor:pointer
}#frases{
        margin-top: 70px;
        margin-left: 20px;
}#mensajeok{
        font-size: 60px;
        color: #9933FF;
        background-color: white;
        text-align: center;
        margin: 10px 200px;
        display: none;
}#mensajeno{
        font-size: 60px;
        color: #9933FF;
        background-color:white;
        text-align: center;
        margin: 10px 150px;
        display: none;
}#mensajepleno{
        font-size: 60px;
        color: #9933FF;
        background-color: white;
        text-align: center;
        margin: 10px 200px;
        display: none;
}#tabla{
        display: inline-block;
        vertical-align: top;
        margin-left: 10px;
        align-content: center;
}
.celda{
        width: 100px;
        height: 50px;
}
#abajo {width: 15px;
        border: 4px solid #CC33FF;
}
.botoncito{
        font-size: 15px;
}
.desaparece{
    background-color:white;
    border: 3px solid white;
    color: white;
    display:inline-block;
    height:110px;
    width:110px;
    vertical-align:top; 
    margin:.3em;
}
#tiempo{
    float:left;
    font-size:30px;
}
#puntos{
    float:right;
    font-size:30px;
}
#tablero span{
    color: white;
    margin-top:1.2em;
    
    font-size:30px;
    text-align:center;  
    vertical-align:middle;

}#jugador{
    color: blue;
    font-size:30px;
    margin: 0px 400px;
    display: none;
}#caja{
    background-color: white;
    width: 220px;
    height: 50px;
    color: blue;
    font-size: 30px;
    text-align: center;

}h1{
    display: inline-block;
    margin: 10px 300px; 
    color: blue;
}#nombrejugador {
  border-radius: 10px;
    padding-bottom: initial;
    color: #FFFFFF;
    background-color: red;
    width: 100px;
    height: 50px;
    margin: 0px 10px;
    font-size: 14px;  
    
    margin-left: 20px;
    margin-top: 0px;
    display: inline;
}#nombrejugador:hover{ 
        cursor:pointer
}#losmejores{
    margin-left: 5px;
    
}#palabro{
    font-weight: bold;
}.países{
        font-size: 50px;
        text-align: center;
        display: none;
}.banderas{
        
        display: none;
}.imagenpais{
        width: 240px;
        height: 195px;
}
<!--Para que no aparezcan las flechitas en la caja --> 
input[type=number]::-webkit-inner-spin-button, 
input[type=number]::-webkit-outer-spin-button { 
  -webkit-appearance: none; 
  margin: 0; 
}
//Firefox:
input[type="number"] {
-moz-appearance: textfield;
}
input[type="number"]:hover,
input[type="number"]:focus {
-moz-appearance: number-input;
}
input[type=number] {
    -moz-appearance:textfield;
}