griddle.css

* {
    margin: 0;
    padding: 0;
    font-family: inherit;
}

html {
    box-sizing: border-box;
}

*,
*:before,
*:after {
    box-sizing: inherit;
}

.container {
    display: grid;
    grid-template-columns: repeat(12, minmax(0, 1fr));
    grid-gap: 15px;
    margin: 0 auto;
}

.container-fluid {
    display: grid;
    grid-template-columns: repeat(12, minmax(0, 1fr));
    grid-gap: 15px;
    margin: 0 auto;
    width: 100%;
}

.grid {
    grid-gap: 15px;
    display: grid;
    grid-template-columns: repeat(12, minmax(0, 1fr));
}

/* No media query since this is the default in Bootstrap */
/* Extra small devices (portrait phones, less than 576px) */

.col-1 {
    grid-column-start: span 1;
}

.col-2 {
    grid-column-start: span 2;
}

.col-3 {
    grid-column-start: span 3;
}

.col-4 {
    grid-column-start: span 4;
}

.col-5 {
    grid-column-start: span 5;
}

.col-6 {
    grid-column-start: span 6;
}

.col-7 {
    grid-column-start: span 7;
}

.col-8 {
    grid-column-start: span 8;
}

.col-9 {
    grid-column-start: span 9;
}

.col-10 {
    grid-column-start: span 10;
}

.col-11 {
    grid-column-start: span 11;
}

.col-12 {
    grid-column-start: span 12;
}

.row-1 {
    grid-row-start: span 1;
}

.row-2 {
    grid-row-start: span 2;
}

.row-3 {
    grid-row-start: span 3;
}

.row-4 {
    grid-row-start: span 4;
}

.row-5 {
    grid-row-start: span 5;
}

.row-6 {
    grid-row-start: span 6;
}

.row-7 {
    grid-row-start: span 7;
}

.row-8 {
    grid-row-start: span 8;
}

.row-9 {
    grid-row-start: span 9;
}

.row-10 {
    grid-row-start: span 10;
}

.row-11 {
    grid-row-start: span 11;
}

.row-12 {
    grid-row-start: span 12;
}

/* Small devices (landscape phones, 576px and up) */
@media (min-width: 576px) {
    .container {
        max-width: 540px;
    }

    .col-sm-1 {
        grid-column-start: span 1;
    }

    .col-sm-2 {
        grid-column-start: span 2;
    }

    .col-sm-3 {
        grid-column-start: span 3;
    }

    .col-sm-4 {
        grid-column-start: span 4;
    }

    .col-sm-5 {
        grid-column-start: span 5;
    }

    .col-sm-6 {
        grid-column-start: span 6;
    }

    .col-sm-7 {
        grid-column-start: span 7;
    }

    .col-sm-8 {
        grid-column-start: span 8;
    }

    .col-sm-9 {
        grid-column-start: span 9;
    }

    .col-sm-10 {
        grid-column-start: span 10;
    }

    .col-sm-11 {
        grid-column-start: span 11;
    }

    .col-sm-12 {
        grid-column-start: span 12;
    }

    .row-sm-1 {
        grid-row-start: span 1;
    }

    .row-sm-2 {
        grid-row-start: span 2;
    }

    .row-sm-3 {
        grid-row-start: span 3;
    }

    .row-sm-4 {
        grid-row-start: span 4;
    }

    .row-sm-5 {
        grid-row-start: span 5;
    }

    .row-sm-6 {
        grid-row-start: span 6;
    }

    .row-sm-7 {
        grid-row-start: span 7;
    }

    .row-sm-8 {
        grid-row-start: span 8;
    }

    .row-sm-9 {
        grid-row-start: span 9;
    }

    .row-sm-10 {
        grid-row-start: span 10;
    }

    .row-sm-11 {
        grid-row-start: span 11;
    }

    .row-sm-12 {
        grid-row-start: span 12;
    }
}

/* Medium devices (tablets, 768px and up) */
@media (min-width: 768px) {
    .container {
        max-width: 720px;
    }

    .col-md-1 {
        grid-column-start: span 1;
    }

    .col-md-2 {
        grid-column-start: span 2;
    }

    .col-md-3 {
        grid-column-start: span 3;
    }

    .col-md-4 {
        grid-column-start: span 4;
    }

    .col-md-5 {
        grid-column-start: span 5;
    }

    .col-md-6 {
        grid-column-start: span 6;
    }

    .col-md-7 {
        grid-column-start: span 7;
    }

    .col-md-8 {
        grid-column-start: span 8;
    }

    .col-md-9 {
        grid-column-start: span 9;
    }

    .col-md-10 {
        grid-column-start: span 10;
    }

    .col-md-11 {
        grid-column-start: span 11;
    }

    .col-md-12 {
        grid-column-start: span 12;
    }

    .row-md-1 {
        grid-row-start: span 1;
    }

    .row-md-2 {
        grid-row-start: span 2;
    }

    .row-md-3 {
        grid-row-start: span 3;
    }

    .row-md-4 {
        grid-row-start: span 4;
    }

    .row-md-5 {
        grid-row-start: span 5;
    }

    .row-md-6 {
        grid-row-start: span 6;
    }

    .row-md-7 {
        grid-row-start: span 7;
    }

    .row-md-8 {
        grid-row-start: span 8;
    }

    .row-md-9 {
        grid-row-start: span 9;
    }

    .row-md-10 {
        grid-row-start: span 10;
    }

    .row-md-11 {
        grid-row-start: span 11;
    }

    .row-md-12 {
        grid-row-start: span 12;
    }
}

/* Large devices (desktops, 992px and up) */
@media (min-width: 992px) {
    .container {
        max-width: 960px;
    }

    .col-lg-1 {
        grid-column-start: span 1;
    }

    .col-lg-2 {
        grid-column-start: span 2;
    }

    .col-lg-3 {
        grid-column-start: span 3;
    }

    .col-lg-4 {
        grid-column-start: span 4;
    }

    .col-lg-5 {
        grid-column-start: span 5;
    }

    .col-lg-6 {
        grid-column-start: span 6;
    }

    .col-lg-7 {
        grid-column-start: span 7;
    }

    .col-lg-8 {
        grid-column-start: span 8;
    }

    .col-lg-9 {
        grid-column-start: span 9;
    }

    .col-lg-10 {
        grid-column-start: span 10;
    }

    .col-lg-11 {
        grid-column-start: span 11;
    }

    .col-lg-12 {
        grid-column-start: span 12;
    }

    .row-lg-1 {
        grid-row-start: span 1;
    }

    .row-lg-2 {
        grid-row-start: span 2;
    }

    .row-lg-3 {
        grid-row-start: span 3;
    }

    .row-lg-4 {
        grid-row-start: span 4;
    }

    .row-lg-5 {
        grid-row-start: span 5;
    }

    .row-lg-6 {
        grid-row-start: span 6;
    }

    .row-lg-7 {
        grid-row-start: span 7;
    }

    .row-lg-8 {
        grid-row-start: span 8;
    }

    .row-lg-9 {
        grid-row-start: span 9;
    }

    .row-lg-10 {
        grid-row-start: span 10;
    }

    .row-lg-11 {
        grid-row-start: span 11;
    }

    .row-lg-12 {
        grid-row-start: span 12;
    }
}

/* Extra large devices (large desktops, 1200px and up) */
@media (min-width: 1200px) {
    .container {
        max-width: 1140px;
    }

    .col-xl-1 {
        grid-column-start: span 1;
    }

    .col-xl-2 {
        grid-column-start: span 2;
    }

    .col-xl-3 {
        grid-column-start: span 3;
    }

    .col-xl-4 {
        grid-column-start: span 4;
    }

    .col-xl-5 {
        grid-column-start: span 5;
    }

    .col-xl-6 {
        grid-column-start: span 6;
    }

    .col-xl-7 {
        grid-column-start: span 7;
    }

    .col-xl-8 {
        grid-column-start: span 8;
    }

    .col-xl-9 {
        grid-column-start: span 9;
    }

    .col-xl-10 {
        grid-column-start: span 10;
    }

    .col-xl-11 {
        grid-column-start: span 11;
    }

    .col-xl-12 {
        grid-column-start: span 12;
    }

    .row-xl-1 {
        grid-row-start: span 1;
    }

    .row-xl-2 {
        grid-row-start: span 2;
    }

    .row-xl-3 {
        grid-row-start: span 3;
    }

    .row-xl-4 {
        grid-row-start: span 4;
    }

    .row-xl-5 {
        grid-row-start: span 5;
    }

    .row-xl-6 {
        grid-row-start: span 6;
    }

    .row-xl-7 {
        grid-row-start: span 7;
    }

    .row-xl-8 {
        grid-row-start: span 8;
    }

    .row-xl-9 {
        grid-row-start: span 9;
    }

    .row-xl-10 {
        grid-row-start: span 10;
    }

    .row-xl-11 {
        grid-row-start: span 11;
    }

    .row-xl-12 {
        grid-row-start: span 12;
    }
}