jQuery带动画效果的CSS3表单输入框验证代码

html,
body {
background-color: #F4F4F4;
display: flex;
width: 100%;
height: 100%;
align-items: center;
font-family: "Work Sans", sans-serif;
justify-content: center;
}

.exp-container {
width: 100%;
padding: 30px;
box-sizing: border-box;
max-width: 600px;
}

.exp {
display: flex;
flex-direction: column-reverse;
width: 100%;
margin-bottom: 30px;
position: relative;
flex-wrap: wrap;
}

.exp__label {
transition: 0.3s;
margin-bottom: 5px;
}

.exp__label:before {
content: attr(data-icon);
font-weight: normal;
font-family: "Ionicons";
font-size: 24px;
position: absolute;
left: 0;
transform: rotateY(90deg);
bottom: 0;
height: 52px;
background: transparent;
color: #000;
transform-origin: left;
display: flex;
align-items: center;
justify-content: center;
transition: color .3s 0s ease, transform .3s 0s ease;
width: 42px;
}

.exp__input {
border: 1px solid #ddd;
padding: 0 10px;
width: 100%;
height: 52px;
transition: 0.3s;
font-weight: normal;
box-sizing: border-box;
font-family: "Work Sans", sans-serif;
outline: none;
}

.exp__input:focus {
padding-left: 42px;
border-color: #bbb;
}

.exp__input:focus + label:before {
transform: rotateY(0deg);
}

.exp__input:valid {
padding-left: 42px;
border-color: green;
}

.exp__input:valid + label {
color: green;
}

非常简单的一款带动画效果的CSS3表单输入框验证代码，当输入框聚焦时出现图标动画，还有验证邮箱地址格式是否正确等功能。