extjs3 - How to set grid height row in extjs -

in code i'm using 4 grids, i've set row height in css this: .x-grid3-row td {line-height: 50px;} , sets rows of grids. need set height row of 1 of grids.

based on id or cls class can specify css eaxch component individually. example,if have grid id sample code be:

.sample .x-grid3-row td {line-height: 50px;}