style.css

.grid-container {
    width: 100%;
    max-width: 1200px;
}
.grid-container * {
    box-sizing: border-box;
}
.row:before, .row:after {
    content: "";
    display: block;
    visibility: hidden;
    clear: both;
    *zoom: 1;
}
[class*="col-"] {
    float: left;
    min-height: 1px;
    width: 16.66%;
    padding: 10px;
}

@media all and (min-width: 768px) {
    .col-md-1 {
        width: 8.33%;
    }
    .col-md-2 {
        width: 16.66%;
    }
    .col-md-3 {
        width: 25%;
    }
    .col-md-4 {
        width: 33.33%;
    }
    .col-md-5 {
        width: 41.66%;
    }
    .col-md-6 {
        width: 50%;
    }
    .col-md-7 {
        width: 58.33%
    }
    .col-md-8 {
        width: 66.66%;
    }
    .col-md-9 {
        width: 75%;
    }
    .col-md-10 {
        width: 83.33%;
    }
    .col-md-11 {
        width: 91.66%
    }
    .col-md-12 {
        width: 100%;
    }
}
@media all and (max-width: 768px) {
    .col-sm-1 {
        width: 8.33%;
    }
    .col-sm-2 {
        width: 16.66%;
    }
    .col-sm-3 {
        width: 25%;
    }
    .col-sm-4 {
        width: 33.33%;
    }
    .col-sm-5 {
        width: 41.66%;
    }
    .col-sm-6 {
        width: 50%;
    }
    .col-sm-7 {
        width: 58.33%
    }
    .col-sm-8 {
        width: 66.66%;
    }
    .col-sm-9 {
        width: 75%;
    }
    .col-sm-10 {
        width: 83.33%;
    }
    .col-sm-11 {
        width: 91.66%
    }
    .col-sm-12 {
        width: 100%;
    }
}