*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: consolas;

}

body{

    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: #333;

}

body.light{

    background: #f8f8f8;

}

.container{

    position: relative;
    min-width: 300px;
    min-height: 400px;
    background: #333;
    padding: 40px 30px 30px;
    border-radius: 20px;
    box-shadow: 25px 25px 75px rgba(0, 0, 0, 0.25), 10px 10px 70px rgba(0, 0, 0, 0.25),
    inset -5px -5px 15px rgba(0, 0, 0, 0.5),
    inset 5px 5px 15px rgba(0, 0, 0, 0.5) ;

}

body.light .container{

    background: #fafafa;
    box-shadow: 25px 25px 75px rgba(0, 0, 0, 0.15), 10px 10px 70px rgba(0, 0, 0, 0.15),
    inset -5px -5px 15px rgba(0, 0, 0, 0.15),
    inset 5px 5px 15px rgba(0, 0, 0, 0.05) ;

}

.calculadora{

    position: relative;
    display: grid;
    
}

.calculadora .value {

    position: relative;
    grid-column: span 4;
    height: 100px;
    width: calc(100% - 20px);
    left: 10px;
    border: none;
    outline: none;
    background: #a7af7c;
    margin-bottom: 10px;
    border-radius: 10px;
    box-shadow: 0 0 0 2px rgba(0, 0, 0, 0.75) ;
    text-align: right;
    padding: 10px;
    font-size: 2em;


}


.calculadora span{

    position: relative;
    display: grid;
    place-items: center;
    width: 80px;
    height: 80px;
    margin: 8px;
    background: linear-gradient(180deg, #2f2f2f, #3f3f3f);
    box-shadow: inset -8px 0 8px rgba(0, 0, 0, 0.15),
    inset 0 -8px 8px rgba(0, 0, 0, 0.25),
    0 0 0 2px rgba(0, 0, 0, 0.75),
    10px 20px 25px rgba(0, 0, 0, 0.4);
    color: #FFF;
    cursor: pointer;
    user-select: none;
    font-weight: 400;
    border-radius: 10px;

}

body.light .calculadora span{

    background: linear-gradient(180deg, #fafafa, #f4f4f4);
    box-shadow: inset -8px 0 8px rgba(0, 0, 0, 0.15),
    inset 0 -8px 8px rgba(0, 0, 0, 0.15),
    0 0 0 2px rgba(0, 0, 0, 1),
    10px 20px 25px rgba(0, 0, 0, 0.25);

}

.calculadora span::before{

    content: '';
    position: absolute;
    top: 3px;
    left: 4px;
    bottom: 14px;
    right: 12px;
    background: linear-gradient(90deg, #2d2d2d, #4d4d4d);
    border-radius: 10px;
    box-shadow: -5px -5px 15px rgba(0, 0, 0, 0.1),
    10px 5px 10px rgba(0, 0, 0, 0.15);
    border-left: 1px solid #0004;
    border-bottom: 1px solid #0004;
    border-top: 1px solid #0009;

}

body.light .calculadora span::before{

    background: linear-gradient(90deg, #e6e6e6, #efefef);
    border-radius: 10px;
    box-shadow: -10px -10px 10px rgba(255, 255, 255, 0.),
    10px 5px 10px rgba(0, 0, 0, 0.15);
    border-left: 1px solid #fff4;
    border-bottom: 1px solid #fff4;
    border-top: 1px solid #fff9;

}

.calculadora span:active{

    filter: brightness(1.5);

}

body.light .calculadora span:active{

    filter: brightness(0.9);

}

.calculadora span i {

    position: relative;
    font-style:  normal;
    font-size: 1.5em;
    text-transform: uppercase;

}
body.light .calculadora span i{

    color: #333;

}

body.light .calculadora span.clear i{

    color: #fff;

}

body.light .calculadora .clear, 

.calculadora .clear{

    grid-column: span 2;
    width: 180px;
    background: #f00;

}

body.light .calculadora .clear::before,

.calculadora .clear::before{

    background: linear-gradient(90deg, #d20000,#ffffff5c);
    border-left: 1px solid #fff4;
    border-bottom: 1px solid #fff4;
    border-top: 1px solid #fff4;

}

.calculadora .plus{

    grid-row: span 2;
    height: 180px;

}

body.light .calculadora .igual, 

.calculadora .igual{

    background: #2196f3;

}

body.light .calculadora .igual::before,

.calculadora .igual::before{

    background: linear-gradient(90deg, #1479c9,#ffffff5c);
    border-left: 1px solid #fff4;
    border-bottom: 1px solid #fff4;
    border-top: 1px solid #fff4;

}

.btn{
    
    position: absolute;
    top: 20px;
    right: 20px;
    width: 60px;
    height: 60px;
    background: #333;
    font-size: 1.5em;
    box-shadow: 5px 5px 15px rgba(0, 0, 0, 0.25),
    5px 5px 30px rgba(0, 0, 0, 0.25),
    inset -2px -2px 5px rgba(0, 0, 0, 0.25),
    inset 2px 2px 5px rgba(0, 0, 0, 0.25);
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    border-radius: 10px;

}

body.light .btn{

    background: #fafafa;
    box-shadow: 5px 5px 15px rgba(0, 0, 0, 0.1),
    5px 5px 30px rgba(0, 0, 0, 0.05),
    inset -2px -2px 5px rgba(0, 0, 0, 0.1),
    inset 2px 2px 5px rgba(0, 0, 0, 0.05);

}

.btn strong{

    display: none;


}

.btn strong:nth-child(1){

    display: block;

}

body.light .btn strong:nth-child(1) {

    display: none;

}

body.light .btn strong:nth-child(2) {

    display: block;

}