Delete

.container {  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr;
  grid-template-rows: 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr;
  gap: 0px 0px;
  grid-auto-flow: row;
  grid-template-areas:
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
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    ". . . . . . . . . . . ."
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    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . .";
}
html, body , .container {
  height: 100%;
  margin: 0;
}
/* For presentation only, no need to copy the code below */
.container * {
  border: 1px solid red;
  position: relative;
}
.container *:after {
  content:attr(class);
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: grid;
  align-items: center;
  justify-content: center;
}

.container {  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr;
  grid-template-rows: 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr;
  gap: 0px 0px;
  grid-auto-flow: row;
  grid-template-areas:
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . ."
    ". . . . . . . . . . . .";
}


html, body , .container {
  height: 100%;
  margin: 0;
}

/* For presentation only, no need to copy the code below */

.container * {
  border: 1px solid red;
  position: relative;
}

.container *:after {
  content:attr(class);
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: grid;
  align-items: center;
  justify-content: center;
}