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

body {
    font-family:'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
    background-color: rgb(240, 161, 59);
}

.caja1 {
    background-color: #ffffff;
    border: 2px solid blue;
    height: 100px;

}

.caja2 {
     background-color: #6b665e;
    border: 2px solid blue;
    height: 300px;
}
.caja3 {
     background-color: #ffffff;
    border: 2px solid blue;
    height: 300px;
}
.caja4 {
     background-color: #6b665e;
    border: 2px solid blue;
    height: 300px;
}
.caja5 {
     background-color: #ffffff;
    border: 2px solid blue;
    height: 300px;
}
.caja6 {
     background-color: #6b665e;
    border: 2px solid blue;
    height: 300px;
}
.caja7 {
     background-color: #ffffff;
    border: 2px solid blue;
    height: 300px;
}
.caja8 {
     background-color: #6b665e;
    border: 2px solid blue;
    height: 300px;
}
.caja9 {
     background-color: #ffffff;
    border: 2px solid blue;
    height: 300px;
}
.caja10 {
     background-color: #6b665e;
    border: 2px solid blue;
    height: 300px;
}
.caja11 {
     background-color: #ffffff;
    border: 2px solid blue;
    height: 300px;
}
.caja12 {
     background-color: #6b665e;
    border: 2px solid blue;
    height: 300px;
}
.caja13 {
     background-color: #ffffff;
    border: 2px solid blue;
    height: 300px;
}
.caja14 {
     background-color: #6b665e;
    border: 2px solid blue;
    height: 300px;
}
.caja15 {
     background-color: #ffffff;
    border: 2px solid blue;
    height: 300px;
}