doctype html
meta charset="utf-8"
p CSSで点滅
/ 参考になるサイト http://qiita.com/junya/items/7c92ea0ac4a41d867dbb
.tgt
.tgt
.tgt
css:
  .tgt {
    width:300px;height:100px;
    background-color:yellow;margin:20px;
    animation: blink 1s infinite 
  }
  @keyframes blink {
    50% {opacity:0}
  }