css3表单交互式特效

5年以前 | 阅读数：336 次 | 编程语言：HTML/CSS

html代码:
<!DOCTYPE html>
<html lang="en" >
<head>
<meta charset="UTF-8">
<title>CSS Form Interactions</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="css/style.css">
</head>
<body>
<section>
  <h1>CSS表单交互</h1>
    <form id="basic-form">
    <div class="form-group">
      <input type="text" id="basic-form-first-name" placeholder="名称"/>
      <label for="basic-form-first-name">名称</label>
    </div>
    <div class="form-group">
      <input type="text" id="basic-form-last-name" placeholder="手机号码"/>
      <label for="basic-form-last-name">手机号码</label>
    </div>
    <div class="form-group">
      <input type="email" id="basic-form-email" placeholder="邮箱"/>
      <label for="basic-form-email">邮箱<span class="error">输入一个有效的电子邮件地址</span></label>
    </div>
    <button id="basic-form-submit" type="submit">发送信息</button>
  </form>
</section>
</body>
</html>

style.css里的css样式：
@import url("https://fonts.googleapis.com/css?family=Lato:400,700");
:root {
  --base-vertical-rhythm: 1.5rem;
  --base-transition: 600ms cubic-bezier(0.22, 1, 0.19, 1);
  --button-bg-color: mediumseagreen;
  --button-border-radius: 0.15rem;
  --button-focus-bg-color: seagreen;
  --button-font-size: 1rem;
  --button-text-color: white;
  --form-font-family: 'Lato', sans-serif;
  --input-bg-color: white;
  --input-border-color: #eaeaea;
  --input-border-focus-color: #d8d8d8;
  --input-border-radius: 0.15rem;
  --input-error-color: red;
  --input-padding: 0.75rem;
  --input-placeholder-color: gray;
  --input-text-color: black;
  --input-underline-color: dodgerblue;
}

* {
  box-sizing: border-box;
}

body {
  display: flex;
  flex-direction: column;
  justify-content: center;
  text-align: left;
  font-family: 'Lato', sans-serif;
  min-height: 100vh;
  padding: 1rem;
  background-color: #fafafa;
}

h1 {
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.2;
}

p {
  font-size: 0.85rem;
  line-height: 1.4;
}

section {
  margin: 0 auto;
  width: 100%;
  max-width: 500px;
}
section > * + * {
  margin-top: var(--base-vertical-rhythm);
}

.form-group {
  position: relative;
  display: flex;
  flex-direction: column-reverse;
  width: 100%;
  border-radius: var(--input-border-radius);
}
.form-group + * {
  margin-top: var(--base-vertical-rhythm);
}

label {
  position: absolute;
  top: var(--input-padding);
  left: calc(var(--input-padding) + 1px);
  margin-bottom: calc(var(--input-padding) * -1.5);
  font-size: 0.5rem;
  letter-spacing: 0.0025rem;
  text-transform: uppercase;
  z-index: 1;
  pointer-events: none;
  opacity: 0;
  -webkit-transform: translateY(calc(var(--input-padding) / 4));
          transform: translateY(calc(var(--input-padding) / 4));
  transition: opacity var(--base-transition), -webkit-transform var(--base-transition);
  transition: opacity var(--base-transition), transform var(--base-transition);
  transition: opacity var(--base-transition), transform var(--base-transition), -webkit-transform var(--base-transition);
}
.form-group:focus-within label {
  opacity: 1;
  -webkit-transform: translateY(0);
          transform: translateY(0);
}
label .error {
  color: var(--input-error-color);
  opacity: 0;
  transition: opacity var(--base-transition);
}
label .error:before {
  content: ' - ';
}

input[type="text"],
input[type="email"] {
  -webkit-appearance: none;
  padding: calc(var(--input-padding) * 1.5) var(--input-padding);
  font-family: var(--form-font-family);
  font-size: 1rem;
  width: 100%;
  color: var(--input-text-color);
  background-color: var(--input-bg-color);
  outline: none;
  border: 1px solid var(--input-border-color);
  border-radius: var(--input-border-radius);
  box-shadow: rgba(0, 0, 0, 0.05) 0 0.5rem 1rem -0.25rem;
  transition: border-color var(--base-transition), box-shadow var(--base-transition), transition var(--base-transition);
}
input[type="text"]::-webkit-input-placeholder,
input[type="email"]::-webkit-input-placeholder {
  color: var(--input-placeholder-color);
  transition: color var(--base-transition), -webkit-transform var(--base-transition);
  transition: color var(--base-transition), transform var(--base-transition);
  transition: color var(--base-transition), transform var(--base-transition), -webkit-transform var(--base-transition);
  transition-delay: 200ms;
}
input[type="text"]:-ms-input-placeholder,
input[type="email"]:-ms-input-placeholder {
  color: var(--input-placeholder-color);
  transition: color var(--base-transition), -webkit-transform var(--base-transition);
  transition: color var(--base-transition), transform var(--base-transition);
  transition: color var(--base-transition), transform var(--base-transition), -webkit-transform var(--base-transition);
  transition-delay: 200ms;
}
input[type="text"]::-ms-input-placeholder,
input[type="email"]::-ms-input-placeholder {
  color: var(--input-placeholder-color);
  transition: color var(--base-transition), -webkit-transform var(--base-transition);
  transition: color var(--base-transition), transform var(--base-transition);
  transition: color var(--base-transition), transform var(--base-transition), -webkit-transform var(--base-transition);
  transition-delay: 200ms;
}
input[type="text"]::placeholder,
input[type="email"]::placeholder {
  color: var(--input-placeholder-color);
  transition: color var(--base-transition), -webkit-transform var(--base-transition);
  transition: color var(--base-transition), transform var(--base-transition);
  transition: color var(--base-transition), transform var(--base-transition), -webkit-transform var(--base-transition);
  transition-delay: 200ms;
}
input[type="text"]:focus,
input[type="email"]:focus {
  border-color: var(--input-border-focus-color);
  box-shadow: none;
}
input[type="text"]:focus::-webkit-input-placeholder,
input[type="email"]:focus::-webkit-input-placeholder {
  color: transparent;
  -webkit-transform: translateX(calc(var(--input-padding) / 2));
          transform: translateX(calc(var(--input-padding) / 2));
  transition-duration: 0ms;
  transition-delay: 0ms;
}
input[type="text"]:focus:-ms-input-placeholder,
input[type="email"]:focus:-ms-input-placeholder {
  color: transparent;
  transform: translateX(calc(var(--input-padding) / 2));
  transition-duration: 0ms;
  transition-delay: 0ms;
}
input[type="text"]:focus::-ms-input-placeholder,
input[type="email"]:focus::-ms-input-placeholder {
  color: transparent;
  transform: translateX(calc(var(--input-padding) / 2));
  transition-duration: 0ms;
  transition-delay: 0ms;
}
input[type="text"]:focus::placeholder,
input[type="email"]:focus::placeholder {
  color: transparent;
  -webkit-transform: translateX(calc(var(--input-padding) / 2));
          transform: translateX(calc(var(--input-padding) / 2));
  transition-duration: 0ms;
  transition-delay: 0ms;
}
input[type="text"]:focus, input[type="text"]:not(:placeholder-shown),
input[type="email"]:focus,
input[type="email"]:not(:placeholder-shown) {
  padding: calc(var(--input-padding) * 2) var(--input-padding) var(--input-padding);
}
input[type="text"]:not(:placeholder-shown):invalid:not(:focus),
input[type="email"]:not(:placeholder-shown):invalid:not(:focus) {
  color: var(--input-error-color);
  border-color: var(--input-error-color);
}
input[type="text"]:not(:placeholder-shown):invalid:not(:focus) + label .error,
input[type="email"]:not(:placeholder-shown):invalid:not(:focus) + label .error {
  opacity: 1;
}
input[type="text"]:not(:placeholder-shown) + label,
input[type="email"]:not(:placeholder-shown) + label {
  opacity: 1;
  -webkit-transform: translateY(0);
          transform: translateY(0);
}
input[type="text"]:-webkit-autofill + label,
input[type="email"]:-webkit-autofill + label {
  opacity: 1;
}

button {
  padding: calc(var(--input-padding) * 1.5) calc(var(--input-padding) * 3);
  width: 100%;
  font-family: var(--form-font-family);
  font-size: var(--button-font-size);
  color: var(--button-text-color);
  background-color: var(--button-bg-color);
  border: none;
  border-radius: var(--button-border-radius);
  box-shadow: rgba(0, 0, 0, 0.05) 0 0.5rem 1rem -0.25rem;
  transition: background-color var(--base-transition), box-shadow var(--base-transition), transition var(--base-transition);
}
button:hover, button:focus {
  cursor: pointer;
  outline: none;
  background-color: var(--button-focus-bg-color);
  box-shadow: none;
  -webkit-transform: translateY(1px);
          transform: translateY(1px);
}
button:active {
  -webkit-transform: translateY(2px);
          transform: translateY(2px);
}

@media (min-width: 400px) {
  button {
    width: auto;
  }
}