Set the big div background image, small div set background color and set the trigger event (when you click the small div, its background color becomes transparent)
<Head><title>Untitled Document</title><styletype= "Text/css">*{margin:0px Auto;padding:0px;}#a1 Div{width:100px;Height:100px;Background-color:#09F;Border:1px solid Black;float: Left;}#a1{width:410px;Height:410px;Background-image:URL (.. /.. /.. /pictures/1437459768106.jpg);}</style></Head><Body><DivID= "A1"> <DivID= "Aa1"onclick= "pic (this)"></Div> <DivID= "Aa2"onclick= "pic (this)"></Div> <DivID= "Aa3"onclick= "pic (this)"></Div> <DivID= "AA4"onclick= "pic (this)"></Div> <DivID= "BB1"onclick= "pic (this)"></Div> <DivID= "Bb2"onclick= "pic (this)"></Div> <DivID= "Bb3"onclick= "pic (this)"></Div> <DivID= "Bb4"onclick= "pic (this)"></Div> <DivID= "CC1"onclick= "pic (this)"></Div> <DivID= "CC2"onclick= "pic (this)"></Div> <DivID= "CC3"onclick= "pic (this)"></Div> <DivID= "CC4"onclick= "pic (this)"></Div> <DivID= "DD1"onclick= "pic (this)"></Div> <DivID= "DD2"onclick= "pic (this)"></Div> <DivID= "DD3"onclick= "pic (this)"></Div> <DivID= "Dd4"onclick= "pic (this)"></Div></Div></Body><Scripttype= "Text/javascript">functionpic (a) {a.style.opacity="0";}</Script>
Minesweeper--Hide the background color of a small lattice