@media screen and (min-width: 1001px){
figure{ width: 33.3%}

}
/当屏幕大于1001px时 每张图片占据整张屏幕的33.33%/
@media screen and (min-width: 601px)and (max-width: 1000px){
figure{ width: 50%}

}
/当屏幕大于601px小于1000px时 每张图片占据整张屏幕的50%/
@media screen and (min-width: 400px ) and (max-width: 600px){
figure{ width: 100%}
}
/当屏幕大于400px小于600px时 每张图片占据整张屏幕的33.33%/