How to make borders collapse (on a div)?

here is a demo

first you need to correct your syntax error its

display: table-cell;

not diaplay: table-cell;

   .container {
    display: table;
    border-collapse:collapse
}
.column {
    display:table-row;
}
.cell {
    display: table-cell;
    border: 1px solid red;
    width: 120px;
    height: 20px;
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}

Use simple negative margin rather than using display table.

Updated in fiddle JS Fiddle

.container { 
    border-style: solid;
    border-color: red;
    border-width: 1px 0 0 1px;
    display: inline-block;
}
.column { 
    float: left; overflow: hidden; 
}
.cell { 
    border: 1px solid red; width: 120px; height: 20px; 
    margin:-1px 0 0 -1px;
}
.clearfix {
    clear:both;
}

Instead using border use box-shadow:

  box-shadow: 
    2px 0 0 0 #888, 
    0 2px 0 0 #888, 
    2px 2px 0 0 #888,   /* Just to fix the corner */
    2px 0 0 0 #888 inset, 
    0 2px 0 0 #888 inset;

Demo: http://codepen.io/Hawkun/pen/rsIEp