simple-css-grid.css

.grid-container {
  width: 100%;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
}

/*-- our cleafix hack -- */
.row:before,
.row:after {
  content:"";
  display: table ;
  clear:both;
}

[class*='col-'] {
  float: left;
  min-height: 1px;
  width: 16.66%;
  /*-- our gutter -- */
  padding: 12px;
}

.col-1 {width: 8.33%;}
.col-2 {width: 16.66%;}
.col-3 {width: 25%;}
.col-4 {width: 33.33%;}
.col-5 {width: 41.66%;}
.col-6 {width: 50%;}
.col-7 {width: 58.33%;}
.col-8 {width: 66.66%;}
.col-9 {width: 75%;}
.col-10 {width: 83.33%;}
.col-11 {width: 91.66%;}
.col-12 {width: 100%;}

@media (max-width:768px){
  .col-3 {width: 50%;}
  .col-4 {width: 50%;}
  .col-4 .last {
    margin-left: auto;
    margin-right: auto;
    float: none;
  }
}

@media (max-width:650px){
  .col-1 {width: 100%;}
  .col-2 {width: 100%;}
  .col-3 {width: 100%;}
  .col-4 {width: 100%;}
  .col-5 {width: 100%;}
  .col-6 {width: 100%;}
  .col-7 {width: 100%;}
  .col-8 {width: 100%;}
  .col-9 {width: 100%;}
  .col-10 {width: 100%;}
  .col-11 {width: 100%;}
  .col-12 {width: 100%;}
}

/*-- some extra column content styling --*/
[class*='col-'] > p {
  padding: 0;
  margin: 0;
  text-align: center;
  color: white;
}