tinygrid.scss (sass) compiled to css - could be optimized a little.

tinygrid.css

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

.grid-full {
  width: 100%;
}

.grid-1-2 {
  float: left;
  width: 50%;
}

.grid-1-3 {
  float: left;
  width: 33.33333%;
}

.grid-1-4 {
  float: left;
  width: 25%;
}

.grid-1-8 {
  float: left;
  width: 12.5%;
}

/*Start responsive breaks*/
@media (max-width: 650px) {
  .break-full {
    float: none;
    width: 100%;
  }
}

@media (max-width: 650px) {
  .break-1-2 {
    width: 50%;
  }
}

@media (max-width: 650px) {
  .break-1-3 {
    width: 33.33333%;
  }
}

@media (max-width: 650px) {
  .break-1-4 {
    width: 25%;
  }
}

/*End responsive breaks*/