享一个用纯 CSS3 实现的，漂亮的 input 输入框动画样式库-Text input love。

点击每个输入框都用不同的动画效果，始终显示标签label，并显示 placeholder（占位符）文本。

html代码：

<div class="row">
 <p>Click every input.</p>
</div>
<div class="row">
 <span>
 <input class="basic-slide" id="name" type="text" placeholder="Your best name" /><label for="name">Name</label>
 </span>
 <span>
 <input class="basic-slide" id="email" type="text" placeholder="Your favorite email" /><label for="email">Email</label>
 </span>
 <span>
 <input class="basic-slide" id="phone" type="text" placeholder="You can trust us" /><label for="phone">Phone</label>
 </span>
</div>
<div class="row">
 <span>
 <input class="clean-slide" id="age" type="text" placeholder="Go for the high score!" /><label for="age">Age</label>
 </span>
 <span>
 <input class="clean-slide" id="height" type="text" placeholder="Heels count" /><label for="height">Height</label>
 </span>
 <span>
 <input class="clean-slide" id="weight" type="text" placeholder="Go ahead and lie" /><label for="weight">Weight</label>
 </span>
</div>
<div class="row">
 <span>
 <input class="gate" id="class" type="text" placeholder="Wizard!" /><label for="class">Class</label>
 </span>
 <span>
 <input class="gate" id="element" type="text" placeholder="Five to choose from" /><label for="element">Element</label>
 </span>
 <span>
 <input class="gate" id="move" type="text" placeholder="Secret book attack!" /><label for="move">Move</label>
 </span>
</div>
<div class="row">
 <span>
 <input class="skinny" id="english" type="text" placeholder="Do you speak it?" /><label for="english">English</label>
 </span>
 <span>
 <input class="skinny" id="burger" type="text" placeholder="A Royale with cheese?" /><label for="burger">Burger</label>
 </span>
 <span>
 <input class="skinny" id="wallet" type="text" placeholder="Bad Mother****er" /><label for="wallet">Wallet</label>
 </span>
</div>
<div class="row">
 <span>
 <input class="slide-up" id="card" type="text" placeholder="Fund me!" /><label for="card">Credit Card</label>
 </span>
 <span>
 <input class="slide-up" id="expires" type="text" placeholder="Month Day, Year" /><label for="expires">Expires</label>
 </span>
 <span>
 <input class="slide-up" id="security" type="text" placeholder="Public" /><label for="security">Security Code</label>
 </span>
</div>
<div class="row">
 <span>
 <input class="card-slide" id="knock" type="text" placeholder="Who's there?" /><label for="knock">Knock knock</label>
 </span>
 <span>
 <input class="card-slide" id="max" type="text" placeholder="Max who?" /><label for="max">Max</label>
 </span>
 <span>
 <input class="card-slide" id="out" type="text" placeholder="Sunuva..." /><label for="out">Maxed out card ;)</label>
 </span>
</div>
<div class="row">
 <span>
 <input class="swing" id="artist" type="text" placeholder="BO$$" /><label for="artist">Artist</label>
 </span>
 <span>
 <input class="swing" id="song" type="text" placeholder="I don't give a ****" /><label for="song">Song</label>
 </span>
 <span>
 <input class="swing" id="eyes" type="text" placeholder="Crazy" /><label for="eyes">Eyes</label>
 </span>
</div>
<div class="row">
 <span>
 <input class="balloon" id="state" type="text" placeholder="Liquid, solid, gaseous..." /><label for="state">State</label>
 </span>
 <span>
 <input class="balloon" id="planet" type="text" placeholder="Probably Earth" /><label for="planet">Planet</label>
 </span>
 <span>
 <input class="balloon" id="galaxy" type="text" placeholder="Milky Way?" /><label for="galaxy">Galaxy</label>
 </span>
</div>

css代码：

@import "compass/css3";
 
@import url(https://fonts.googleapis.com/css?family=Open+Sans:400,700,600,300,800);
 
* {
 box-sizing: border-box;
}
html,
body {
 overflow-x: hidden;
 font-family: "Open Sans", sans-serif;
 font-weight: 300;
 color: #fff;
 background: #efefef;
}
@mixin epic-sides() { // https://codepen.io/MichaelArestad/pen/qltuk
 position: relative;
 z-index: 1;
 
 &:before {
 position: absolute;
 content: "";
 display: block;
 top: 0;
 left: -5000px;
 height: 100%;
 width: 15000px;
 z-index: -1;
 @content;
 }
}
.row {
 max-width: 800px;
 margin: 0 auto;
 padding: 60px 30px;
 background: #032429;
 @include epic-sides() {background: inherit;}
 text-align: center;
 
 &:first-child {
 padding: 40px 30px;
 }
 &:nth-child(2),
 &:nth-child(8),
 &:nth-child(10){
 background: #134A46;
 }
 &:nth-child(3),
 &:nth-child(7) {
 background: #377D6A;
 }
 &:nth-child(4),
 &:nth-child(6) {
 background: #7AB3;
 }
 &:nth-child(5) {
 background: #B2E3AF;
 }
 
 span {
 position: relative;
 display: inline-block;
 margin: 30px 10px;
 }
}
.basic-slide {
 display: inline-block;
 width: 215px;
 padding: 10px 0 10px 15px;
 font-family: "Open Sans", sans;
 font-weight: 400;
 color: #377D6A;
 background: #efefef;
 border: 0;
 border-radius: 3px;
 outline: 0;
 text-indent: 70px; // Arbitrary.
 transition: all .3s ease-in-out;
 
 &::-webkit-input-placeholder {
 color: #efefef;
 text-indent: 0;
 font-weight: 300;
 }
 
 + label {
 display: inline-block;
 position: absolute;
 top: 0;
 left: 0;
 padding: 10px 15px;
 text-shadow: 0 1px 0 rgba(19,74,70,.4);
 background: #7AB3;
 transition: all .3s ease-in-out;
 border-top-left-radius: 3px;
 border-bottom-left-radius: 3px;
 }
}
.basic-slide:focus,
.basic-slide:active {
 color: #377D6A;
 text-indent: 0;
 background: #fff;
 border-top-left-radius: 0;
 border-bottom-left-radius: 0;
 
 &::-webkit-input-placeholder {
 color: #aaa;
 }
 + label {
 transform: translateX(-100%);
 }
}
.clean-slide {
 position: relative;
 display: inline-block;
 width: 215px;
 padding: 10px 0 10px 15px;
 font-family: "Open Sans", sans;
 font-weight: 400;
 color: #377D6A;
 background: #efefef;
 border: 0;
 border-radius: 3px;
 outline: 0;
 text-indent: 60px; // Arbitrary.
 transition: all .3s ease-in-out;
 
 &::-webkit-input-placeholder {
 color: #efefef;
 text-indent: 0;
 font-weight: 300;
 }
 
 + label {
 display: inline-block;
 position: absolute;
 transform: translateX(0);
 top: 0;
 left: 0;
 bottom: 0;
 padding: 13px 15px;
 font-size: 11px;
 font-weight: 700;
 text-transform: uppercase;
 color: #032429;
 text-align: left;
 text-shadow: 0 1px 0 rgba(255,255,255,.4);
 transition: all .3s ease-in-out, color .3s ease-out;
 border-top-left-radius: 3px;
 border-bottom-left-radius: 3px;
 overflow: hidden;
 
 &:after {
 content: "";
 position: absolute;
 top: 0;
 right: 100%;
 bottom: 0;
 width: 100%;
 background: #7AB3;
 z-index: -1;
 transform: translate(0);
 transition: all .3s ease-in-out;
 border-top-left-radius: 3px;
 border-bottom-left-radius: 3px;
 }
 }
}
.clean-slide:focus,
.clean-slide:active {
 color: #377D6A;
 text-indent: 0;
 background: #fff;
 border-top-left-radius: 0;
 border-bottom-left-radius: 0;
 
 &::-webkit-input-placeholder {
 color: #aaa;
 }
 + label {
 color: #fff;
 text-shadow: 0 1px 0 rgba(19,74,70,.4);
 transform: translateX(-100%);
 
 &:after {
 transform: translate(100%);
 }
 }
}
.gate {
 display: inline-block;
 width: 215px;
 padding: 10px 0 10px 15px;
 font-family: "Open Sans", sans;
 font-weight: 400;
 color: #377D6A;
 background: #efefef;
 border: 0;
 border-radius: 3px;
 outline: 0;
 text-indent: 65px; // Arbitrary.
 transition: all .3s ease-in-out;
 
 &::-webkit-input-placeholder {
 color: #efefef;
 text-indent: 0;
 font-weight: 300;
 }
 
 + label {
 display: inline-block;
 position: absolute;
 top: 0;
 left: 0;
 padding: 10px 15px;
 text-shadow: 0 1px 0 rgba(19,74,70,.4);
 background: #7AB3;
 transition: all .4s ease-in-out;
 border-top-left-radius: 3px;
 border-bottom-left-radius: 3px;
 transform-origin: left bottom;
 z-index: 99;
 
 &:before,
 &:after {
 content: "";
 position: absolute;
 top: 0;
 right: 0;
 bottom: 0;
 left: 0;
 border-radius: 3px;
 background: #377D6A;
 transform-origin: left bottom;
 transition: all .4s ease-in-out;
 pointer-events: none;
 z-index: -1;
 }
 &:before {
 background: rgba(3,36,41,.2);
 z-index: -2;
 right: 20%;
 }
 }
}
span:nth-child(2) .gate {
 text-indent: 85px;
}
span:nth-child(2) .gate:focus,
span:nth-child(2) .gate:active{
 text-indent: 0;
}
.gate:focus,
.gate:active {
 color: #377D6A;
 text-indent: 0;
 background: #fff;
 border-top-right-radius: 3px;
 border-bottom-right-radius: 3px;
 
 &::-webkit-input-placeholder {
 color: #aaa;
 }
 + label {
 transform: rotate(-66deg);
 border-radius: 3px;
 
 &:before {
 transform: rotate(10deg);
 }
 }
}
.skinny {
 display: inline-block;
 width: 215px;
 padding: 10px 0 10px 15px;
 font-family: "Open Sans", sans;
 font-weight: 400;
 color: #377D6A;
 background: #efefef;
 border: 0;
 border-radius: 3px;
 outline: 0;
 text-indent: 75px; // Arbitrary.
 transition: all .3s ease-in-out;
 
 &::-webkit-input-placeholder {
 color: #efefef;
 text-indent: 0;
 font-weight: 300;
 }
 
 + label {
 display: inline-block;
 position: absolute;
 transform: translateX(0);
 top: 0;
 left: 0;
 padding: 10px 15px;
 text-shadow: 0 1px 0 rgba(19,74,70,.4);
 transition: all .3s ease-in-out;
 border-top-left-radius: 3px;
 border-bottom-left-radius: 3px;
 overflow: hidden;
 
 &:before,
 &:after {
 content: "";
 position: absolute;
 right: 0;
 left: 0;
 z-index: -1;
 transition: all .3s ease-in-out;
 }
 &:before {
 // Skinny bit here
 top: 5px;
 bottom: 5px;
 background: #377D6A; // change this to #134A46
 border-top-left-radius: 3px;
 border-bottom-left-radius: 3px;
 }
 &:after {
 top: 0;
 bottom: 0;
 background: #377D6A;
 }
 }
}
.skinny:focus,
.skinny:active {
 color: #377D6A;
 text-indent: 0;
 background: #fff;
 
 &::-webkit-input-placeholder {
 color: #aaa;
 }
 + label {
 transform: translateX(-100%);
 
 &:after {
 transform: translateX(100%);
 }
 }
}
.slide-up {
 display: inline-block;
 width: 215px;
 padding: 10px 0 10px 15px;
 font-family: "Open Sans", sans;
 font-weight: 400;
 color: #377D6A;
 background: #efefef;
 border: 0;
 border-radius: 3px;
 outline: 0;
 text-indent: 80px; // Arbitrary.
 transition: all .3s ease-in-out;
 
 &::-webkit-input-placeholder {
 color: #efefef;
 text-indent: 0;
 font-weight: 300;
 }
 
 + label {
 display: inline-block;
 position: absolute;
 transform: translateX(0);
 top: 0;
 left: 0;
 padding: 10px 15px;
 text-shadow: 0 1px 0 rgba(19,74,70,.4);
 transition: all .3s ease-in-out;
 border-top-left-radius: 3px;
 border-bottom-left-radius: 3px;
 overflow: hidden;
 
 &:before,
 &:after {
 content: "";
 position: absolute;
 right: 0;
 left: 0;
 z-index: -1;
 transition: all .3s ease-in-out;
 }
 &:before {
 // Skinny bit here
 top: 6px;
 left: 5px;
 right: 5px;
 bottom: 6px;
 background: #377D6A; // change this to #134A46
 }
 &:after {
 top: 0;
 bottom: 0;
 background: #377D6A;
 }
 }
}
span:nth-child(1) .slide-up {
 text-indent: 105px;
}
span:nth-child(3) .slide-up {
 text-indent: 125px;
}
span:nth-child(1) .slide-up:focus,
span:nth-child(1) .slide-up:active,
span:nth-child(3) .slide-up:focus,
span:nth-child(3) .slide-up:active {
 text-indent: 0;
}
.slide-up:focus,
.slide-up:active {
 color: #377D6A;
 text-indent: 0;
 background: #fff;
 
 &::-webkit-input-placeholder {
 color: #aaa;
 }
 + label {
 transform: translateY(-100%);
 
 &:before {
 border-radius: 5px;
 }
 &:after {
 transform: translateY(100%);
 }
 }
}
.card-slide {
 display: inline-block;
 width: 215px;
 padding: 10px 0 10px 15px;
 font-family: "Open Sans", sans;
 font-weight: 400;
 color: #377D6A;
 background: #efefef;
 border: 0;
 border-radius: 3px;
 outline: 0;
 text-indent: 115px; // Arbitrary.
 transition: all .3s ease-in-out;
 
 &::-webkit-input-placeholder {
 color: #efefef;
 text-indent: 0;
 font-weight: 300;
 }
 
 + label {
 display: block;
 position: absolute;
 top: 0;
 left: 0;
 padding: 10px 15px;
 text-shadow: 0 1px 0 rgba(19,74,70,.4);
 background: #7AB3;
 transition: all .3s ease-in-out;
 border-top-left-radius: 3px;
 border-bottom-left-radius: 3px;
 transform-origin: right center;
 transform: perspective(300px) scaleX(1) rotateY(0deg);
 }
}
span:nth-child(2) .card-slide {
 text-indent: 55px;
}
span:nth-child(3) .card-slide {
 text-indent: 150px;
}
span:nth-child(2) .card-slide:focus,
span:nth-child(2) .card-slide:active,
span:nth-child(3) .card-slide:focus,
span:nth-child(3) .card-slide:active {
 text-indent: 0;
}
.card-slide:focus,
.card-slide:active {
 color: #377D6A;
 text-indent: 0;
 background: #fff;
 border-top-left-radius: 0;
 border-bottom-left-radius: 0;
 
 &::-webkit-input-placeholder {
 color: #aaa;
 }
 + label {
 transform: perspective(600px) translateX(-100%) rotateY(80deg);
 }
}
.swing {
 display: inline-block;
 width: 215px;
 padding: 10px 0 10px 15px;
 font-family: "Open Sans", sans;
 font-weight: 400;
 color: #377D6A;
 background: #efefef;
 border: 0;
 border-radius: 3px;
 outline: 0;
 text-indent: 60px; // Arbitrary.
 transition: all .3s ease-in-out;
 
 &::-webkit-input-placeholder {
 color: #efefef;
 text-indent: 0;
 font-weight: 300;
 }
 
 + label {
 display: inline-block;
 position: absolute;
 top: 0;
 left: 0;
 padding: 10px 15px;
 text-shadow: 0 1px 0 rgba(19,74,70,.4);
 background: #7AB3;
 border-top-left-radius: 3px;
 border-bottom-left-radius: 3px;
 transform-origin: 2px 2px;
 transform: rotate(0);
 // There should be a better way
 animation: swing-back .4s 1 ease-in-out;
 }
}
@keyframes swing {
 0% {
 transform: rotate(0);
 }
 20% {
 transform: rotate(116deg);
 }
 40% {
 transform: rotate(60deg);
 }
 60% {
 transform: rotate(98deg);
 }
 80% {
 transform: rotate(76deg);
 }
 100% {
 transform: rotate(82deg);
 }
}
@keyframes swing-back {
 0% {
 transform: rotate(82deg);
 }
 100% {
 transform: rotate(0);
 }
}
.swing:focus,
.swing:active {
 color: #377D6A;
 text-indent: 0;
 background: #fff;
 border-top-left-radius: 0;
 border-bottom-left-radius: 0;
 
 &::-webkit-input-placeholder {
 color: #aaa;
 }
 + label {
 animation: swing 1.4s 1 ease-in-out;
 transform: rotate(82deg);
 }
}
.balloon {
 // As suggested by https://.com/dbox/status/3658884986985728
 display: inline-block;
 width: 215px;
 padding: 10px 0 10px 15px;
 font-family: "Open Sans", sans;
 font-weight: 400;
 color: #377D6A;
 background: #efefef;
 border: 0;
 border-radius: 3px;
 outline: 0;
 text-indent: 60px; // Arbitrary.
 transition: all .3s ease-in-out;
 
 &::-webkit-input-placeholder {
 color: #efefef;
 text-indent: 0;
 font-weight: 300;
 }
 
 + label {
 display: inline-block;
 position: absolute;
 top: 8px;
 left: 0;
 bottom: 8px;
 padding: 5px 15px;
 color: #032429;
 font-size: 11px;
 font-weight: 700;
 text-transform: uppercase;
 text-shadow: 0 1px 0 rgba(19,74,70,0);
 transition: all .3s ease-in-out;
 border-radius: 3px;
 background: rgba(122,184,147,0);
 
 &:after {
 position: absolute;
 content: "";
 width: 0;
 height: 0;
 top: 100%;
 left: 50%;
 margin-left: -3px;
 border-left: 3px solid transparent;
 border-right: 3px solid transparent;
 border-top: 3px solid rgba(122,184,147,0);
 transition: all .3s ease-in-out;
 }
 }
}
.balloon:focus,
.balloon:active {
 color: #377D6A;
 text-indent: 0;
 background: #fff;
 
 &::-webkit-input-placeholder {
 color: #aaa;
 }
 + label {
 color: #fff;
 text-shadow: 0 1px 0 rgba(19,74,70,.4);
 background: rgba(122,184,147,1);
 transform: translateY(-40px);
 
 &:after {
 border-top: 4px solid rgba(122,184,147,1);
 }
 }
}