sencha touch 2 - Nesting in css3 -

i new css , sencha touch 2. while working on tutorial on sencha touch 2,i see css file having code

/* increase height of list item title , narrative fit */ .x-list .x-list-item {      min-height: 10.5em!important;      height:7.5em; } /* move disclosure button account list item height increase */ .x-list .x-list-disclosure {      position: absolute;      bottom: 4.0em;      right: 0.10em; } 

is .x-list .x-list-item css nesting concept , x-list class name? , concept purely css concept or sencha touch concept?

it's pure css concept, syntax means

.x-list .x-list-item  

select element class x-list-item nested under element having class x-list

the same goes second syntax.

if want make more stricter, can use element.class selector select if matches element.class combination, if taken example..

using like

div.x-list span.x-list-item {    /* select span having class        x-list-item nested under div element having class        x-list */ }