css输入框动效

源码

<div class="container">
	<form>
		<div class="group">
			<input type="text" required>
			<span class="highlight"></span>
			<span class="bar"></span>
			<label>Name</label>
		</div>
		<div class="group">
			<input type="text" required>
			<span class="highlight"></span>
			<span class="bar"></span>
			<label>Email</label>
		</div>
	</form>
</div>
<style>
* {
  box-sizing: border-box;
}
.container {
  font-family: "Roboto";
  width: 600px;
  margin: 30px auto;
  display: block;
  background: #fff;
  padding: 10px 50px 50px;
}
.group {
  position: relative;
  margin-bottom: 45px;
}
input {
  font-size: 18px;
  padding: 10px 10px 10px 5px;
  display: block;
  width: 300px;
  border: none;
  border-bottom: 1px solid #757575;
}
input:focus {
  outline: none;
}
label {
  color: #999;
  font-size: 18px;
  font-weight: normal;
  position: absolute;
  pointer-events: none;
  left: 5px;
  top: 10px;
  transition: 0.2s ease all;
}
input:focus ~ label,input:valid ~ label {
  top: -20px;
  font-size: 14px;
  color: #5264ae;
}
.bar {
  position: relative;
  display: block;
  width: 300px;
}
.bar:before,.bar:after {
  content: "";
  height: 2px;
  width: 0;
  bottom: -1px;
  position: absolute;
  background: #5264ae;
  transition: 0.2s ease all;
}
.bar:before {
  left: 50%;
}
.bar:after {
  right: 50%;
}
input:focus ~ .bar:before,
input:focus ~ .bar:after {
  width: 50%;
}
.highlight {
  position: absolute;
  height: 60%;
  width: 100px;
  top: 25%;
  left: 0;
  pointer-events: none;
  opacity: 0.5;
}
input:focus ~ .highlight {
  animation: inputHighlighter 0.3s ease;
}
@keyframes inputHighlighter {
  from {
    background: #5264ae;
  }
  to {
    width: 0;
    background: transparent;
  }
}
</style>

链接: https://fly63.com/course/33_1615