*{
    padding: 0;
    margin: 0;
}

.contenedor{
    display: grid;
    grid-template-areas: "header"
                        "calculadora"
                        "basic";
}

.header{
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    background-color: rgb(162, 229, 162);
    position: -webkit-sticky;
    position: sticky;
    top:0;
    z-index: 1000;
}

.logo{
    display:flex;
    justify-content: space-between;
}

.logo img{
    width: 220px;
    height: auto;

}

.nav{
    font-size: 18px;
}

.nav ul{
    display: flex;
    list-style: none;
    padding: 5px;
    margin: 5px;
}


.nav ul li a{
    display: block;
    padding: 5px 15px;
    color: black;
    text-decoration: none;
    cursor: pointer;
    border-radius: 3px;
    transition: all 0.3 ease;
}
.nav ul li a:hover{
    background-color: rgba(17, 101, 72, 0.539);
    color: rgb(255, 255, 255);
}


h2{
    padding: 5px;
}

.item{
    text-align: center;
}
.op{
    text-align: center;
    padding: 10px;
    margin: 10px;
    border-radius: 15px;
}
.op h3{
    padding: 7px;
}

#suma{
    background-color: rgba(95, 215, 129, 0.664);
}

#resta{
    background-color: rgba(121, 180, 200, 0.628);
}
#div{
    background-color: rgba(199, 127, 213, 0.671);
}
#mult{
    background-color: rgba(89, 186, 164, 0.614);
}