*{
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: #0096d1;
    font-family: Arial, sans-serif;
}

.caja1{
    background-color: #ffff;
    border: 2px solid #000;
    height: 100px;
    
}
.caja2{
    background-color: #9c9c9c;
    border: 2px solid #000;
    height: 300px;;
    display: flex;
    justify-content: center;

}
.caja3{
    background-color: #ffff;
    border: 2px solid #000;
    height: 300px;;
    display: flex;
    justify-content: center
}
.caja4{
    background-color: #9c9c9c;
    border: 2px solid #000;
    height: 300px;;
    display: flex;
    justify-content: center
}
.caja5{
    background-color: #ffff;
    border: 2px solid #000;
    height: 300px;;
    display: flex;
    justify-content: center
}
.caja6{
    background-color: #9c9c9c;
    border: 2px solid #000;
    height: 300px;;
    display: flex;
    justify-content: center
}
.caja7{
    background-color: #ffff;
    border: 2px solid #000;
    height: 300px;;
    display: flex;
    justify-content: center
}
.caja8{
    background-color: #9c9c9c;
    border: 2px solid #000;
    height: 300px;;
}
.caja9{
    background-color: #ffff;
    border: 2px solid #000;
    height: 300px;;
}
.caja10{
    background-color: #9c9c9c;
    border: 2px solid #000;
    height: 300px;;
}
.caja11{
    background-color: #ffff;
    border: 2px solid #000;
    height: 300px;;
}
.caja12{
    background-color: #9c9c9c;
    border: 2px solid #000;
    height: 300px;;
}
.caja13{
    background-color: #ffff;
    border: 2px solid #000;
    height: 300px;;
}
.caja14{
    background-color: #9c9c9c;
    border: 2px solid #000;
    height: 300px;;
}
.caja15{
    background-color: #ffff;
    border: 2px solid #000;
    height: 300px;;
}