使用CSS3制作首页登录界面实例

响应式设计

在这个页面中,使用下面3点来完成响应式设计

1、最大宽度 .设定了一个 max-width 的最大宽度,以便在大屏幕时兼容.；

2、margin : 30px auto; 使其保持时刻居中；

3、输入用户名，密码时需要将元素上移20px，使其为触发状态，并使字体缩小4px；

4、内容主色调采用#18B4ED；

DEMO页面Html：

<div class="container    <div class="logo">

        <div class="logo-block-top">
        </div>
        <div class="logo-block-bottom">
            <div id="FiveStar"></div>
        </div>
    </div>
    <h4 class="login-header">用户登录</h4>
    <div class="content">
        <div class="form-group">
            <input type="text" required class="form-control">
            <label class="form-label">用户名</label>
        </div>
        <div class="form-group">
            <input type="password" required class="form-control">
            <label class="form-label">密 码</label>
        </div>
    </div>
</div>

DEMO对应的CSS样式：

给 整体body 添加样式：

body,html {
    font-family: "Microsoft Ya Hei";
    background-color: #18b4ed;
    color: #777;
}

登录模块版心样式：

.container{
    position: relative;
    backface-visibility: hidden;
    max-width: 360px;
    margin: 30px auto;
    padding: 45px 20px;
    border-radius: 4px;
    box-shadow: 2px 2px 5px rgba(0, 0, 0, 0.3);
    background-color: #fff;
    box-sizing: border-box;
}

头部logo背景的样式（应用伪类：after属性）：

.container>.logo {
    height: 150px;
    width: 150px;
    position: relative;
    background-color: #EFEFEF;
    border-radius: 75px;
    margin: 0 auto;
}
.container>.logo::after {
    content: “”;
    height: 150px;
    width: 75px;
    position: absolute;
    background-color: #E1E1E1;
    border-radius: 0 75px 75px 0;
    left: 75px;
    top: 0;
}

接下来就是添加logo：

.container>.logo>.logo-block-top {
    box-sizing: border-box;
    height: 45px;
    width: 54px;
    border: 10px solid #E6E6FA;
    border-bottom: 0;
    position: absolute;
    border-radius: 27px 27px 0 0;
    left: 48px;
    z-index: 1001;
    top: 20px;
}
.container>.logo>.logo-block-bottom {
    position: absolute;
    height: 60px;
    width: 80px;
    box-sizing: border-box;
    background-color: #FFA000;
    z-index: 1001;
    top: 65px;
    left: 35px;
    border-radius: 7px;
}
.FiveStar {
    width: 0;
    height: 0;
    float: left;
    margin: 20px;
    color: #ff0012;
    position: relative;
    border-right: 20px solid transparent;
    border-bottom: 15px solid #ff0012;
    border-left: 20px solid transparent;
    transform: rotate(35deg);
}
.FiveStar:before {
    height: 0;
    width: 0;
    content: '';
    position: absolute;
    top: -11px;
    left: -12px;
    border-bottom: 15px solid #ff0012;
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    transform: rotate(-35deg);
}
.FiveStar:after {
    width: 0;
    height: 0;
    content: '';
    position: absolute;
    top: 0;
    left: -20px;
    color: #ff0012;
    border-right: 20px solid transparent;
    border-bottom: 15px solid #ff0012;
    border-left: 20px solid transparent;
    transform: rotate(-70deg);
}

页面文本提示：

.container>.login-title {
    text-align: center;
    font-size: 22px;
    color: #18b4ed;
    font-weight: 200;
    margin: 15px 0 18px 0;
}

用户登录input框应用：

.container>.content {
    width: 90%;
    margin: 0 auto;
}
.container>.content>.form-group {
    position: relative;
}
.container>.content>.form-group>.form-control {
    z-index: 3;
    position: relative;
    height: 58px;
    width: 100%;
    border: 0;
    border-bottom: 1px solid #777;
    padding-top: 22px;
    color: #18b4ed;
    font-size: 12px;
    background: none;
    box-sizing: border-box;
    outline: none;
    display: inline-block;
    -webkit-transition: 0.3s;
    transition: 0.3s;
}
.container>.content>.form-group>.form-label {
    z-index: 1;
    position: absolute;
    bottom: 10px;
    left: 0;
    font-size: 15px;
    -webkit-transition: 0.3s;
    transition: 0.3s;
}
.container>.content>.form-group>:first-child {
    margin-bottom: 5px;
}

添加input触发效果：

.container>.content>.form-group>.form-control:focus,
.container>.content>.form-group>.form-control:valid {
    box-shadow: 0 1px #18b4ed;
    border-color: #18b4ed;
}

.container>.content>.form-group>.form-control:focus+.form-label,
.container>.content>.form-group>.form-control:valid+.form-label {
    font-size: 12px;
    -ms-transform: translateY(-20px);
    -webkit-transform: translateY(-20px);
    transform: translateY(-25px);
}

至此，一个简单的DEMO登录页就完成！