.container_12 {
  margin-left: auto;
  margin-right: auto;
  max-width: 1000px;
  width: 100%;
  padding: 0 20px;
  position: relative;
  box-sizing: border-box;
  display: flex;
  flex-wrap: wrap;
}

[class*="grid_"] {
  box-sizing: border-box;
  padding: 10px;
  float: left;
  width: 100%;
}

/* Desktop layout (≥992px) */
@media (min-width: 767px) {
  .grid_1 { width: 8.33%; }
  .grid_2 { width: 16.66%; }
  .grid_3 { width: 25%; }
  .grid_4 { width: 33.33%; }
  .grid_5 { width: 41.66%; }
  .grid_6 { width: 50%; }
  .grid_7 { width: 58.33%; }
  .grid_8 { width: 66.66%; }
  .grid_9 { width: 75%; }
  .grid_10 { width: 83.33%; }
  .grid_11 { width: 91.66%; }
  .grid_12 { width: 100%; }
}

/* Optional prefix/suffix (can be margin or padding depending on usage) */
[class*="prefix_"], [class*="suffix_"] {
  box-sizing: border-box;
}

/* Utility classes */
.clear {
  clear: both;
  display: block;
  overflow: hidden;
  visibility: hidden;
  height: 0;
}