iview-input placeholder 样式修改

 /deep/ .ivu-input::-webkit-input-placeholder {
          color: #87cfff;
        }
        /deep/ .ivu-input::-moz-placeholder {
          /* Mozilla Firefox 19+ */
          color: #87cfff;
        }
        /deep/ .ivu-input::-moz-placeholder {
          /* Mozilla Firefox 4 to 18 */
          color: #87cfff;
        }
        /deep/ .ivu-input::-ms-input-placeholder {
          /* Internet Explorer 10-11 */
          color: #87cfff;
        }