* {box-sizing: border-box;}
label {width: 100%;height: 100%;border:1px dashed #333;position:absolute;}
input {position: absolute;clip: rect(0,0,0,0);overflow: hidden;}
span {position:absolute; top: 50%;font-size: 18px;width: 100%;text-align: center;}
img {width: 100%;position: relative;}