<div class="wrapper">
<input class="input" type="text" palceholder="请输入"/>
<span>获取验证码</span>
</div>
.wrapper {
height: 40px;
background-color: yellow;
display: flex;
align-items: center;
}
.input {
flex: 1;
height: 20px;
}
span {
margin-left: 10px;
}