.ad{min-width: 320px;max-width: 640px;margin:45px 0 auto; overflow: hidden;position: relative; }
.ad img{width:100%; border: none; position:relative;}
.ad span{background:#ff2556; padding:0.25rem 0.3rem; border-radius:1rem 0 0 1rem; display:inline-block; font-size:0.6rem;color:#fff; position:absolute;top:10px; right:0;}