效果如图：

html代码如下：

 <div class="box">
              <div class="searchBox">
                <input type="text" v-model="keyword" placeholder="请输入关键词进行搜索" class="searchInput" style="padding-left: 10px;">
                <input type="button"  @click="_search" value="搜索" class="searchButton">
              </div>
            </div>

css代码如下：

.box{
    margin: 0 auto;
    padding-top: 80px;
    height: 50px;
    width: 100%;
  }
  .searchBox{
    margin: 0 auto;
    width: 60%;
    position: relative;
  }
  .searchInput{
    display: inline-block;
    width: 85%;
    height: 38px;
    border: 1px solid #cccccc;
    float: left;
    box-sizing: border-box;
    -moz-box-sizing:border-box; /* Firefox */
    -webkit-box-sizing:border-box; /* Safari */
    border-bottom-left-radius: 5px;
    border-top-left-radius: 5px;
  }
  .searchButton{
    display: inline-block;
    width: 15%;
    height: 38px;
    line-height: 40px;
    float: left;
    background-color: #00a0e9;
    font-size: 16px;
    cursor: pointer;
    border-bottom-right-radius: 5px;
    border-top-right-radius: 5px;
    border: none;
    color: #fff;
  }