CSS min-width vs max-width

minmax.css

@media screen and (min-width:100px) { /* Screen >= 100 */
    body { font-weight:bold; }
}

@media screen and (min-width:200px) { /* Screen >= 200 */
    body { color:#555; }
}

@media screen and (max-width:100px) { /* Screen <= 100 */
    body { font-weight:bold; }
}

@media screen and (max-width:200px) { /* Screen <= 200 */
    body { color:#555; }
}

/* 
min-* means greater than or equals to x
max-* means less than or equals to x
*/