留言板将用于我们的许多项目。该设计的目的是收集目标用户的信息，以便我们能够及时链接用户，解决用户的问题，然后实现其功能和价值。
因此，今天我们练习一个简单留言表单的实现，具体效果，可以看下面的截图：
在今天的小练习中，我们没有使用任何复杂的图片材料，只是使用了一些简单的材料ICON图标，这些图标都来自阿里巴巴矢量图库，如有必要，可自行下载获取，ICON图标地址：https://www.iconfont.cn/我不会在这里上传这些ICON图标素材。
接下来，让我们来看看代码实现过程。建议初学者多练习。也许你认为你在做重复的事情，但我们只能在学习之前这样做。
HTML代码：
<!doctype html><html><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>【每日练习】27—CSS实现留言板效果</title></head><body><section><div class="container"><div class="contactinfo"><div><h2>联系方式</h2><ul class="info"><li><span><img src="location.png"></span><span>地球-世界-中国-上海-闵行区-东川路</span></li><li><span><img src="mail.png"></span><span>13127757553@163.com</span></li><li><span><img src="call.png"></span><span>13127757553</span></li></ul></div><ul class="sci"><li><a href="http://www.webqdkf.com"><img src="1.png"></a></li><li><a href="http://www.webqdkf.com"><img src="2.png"></a></li><li><a href="http://www.webqdkf.com"><img src="3.png"></a></li><li><a href="http://www.webqdkf.com"><img src="4.png"></a></li><li><a href="http://www.webqdkf.com"><img src="5.png"></a></li></ul></div><div class="contactForm"><h2>留言联系</h2><div class="formBox"><div class="inputBox w50"><input type="text" name="" required><span>昵称</span></div><div class="inputBox w50"><input type="text" name="" required><span>姓名</span></div><div class="inputBox w50"><input type="text" name="" required><span>邮箱地址</span></div><div class="inputBox w50"><input type="text" name="" required><span>联系电话</span></div><div class="inputBox w100"><textarea name="" required></textarea><span>如果您有任何问题，请留言。我会尽快回复你</span></div><div class="inputBox w100"><input type="submit" value="提交"></div></div></div></div></section></body></html>
CSS代码：
*{margin: 0;padding: 0;box-sizing: border-box;font-family: 'Poppins' ,sans-serif;}section{position: relative;display: flex;justify-content: center;align-items: center;min-height: 100vh;background: #112d42;}section::before{content: '';position: absolute;top: 0;left: 0;width: 50%;height: 100%;background: #00a6bc;}section .container{position: relative;min-width: 1100px;min-height: 550px;display: flex;z-index: 1000;}section .container .contactinfo{position: absolute;top: 40px;width: 350px;height: calc(100% - 80px);background: #0f3959;z-index: 1;padding: 40px;display: flex;flex-direction: column;justify-content: space-between;box-shadow: 0 20px 20px rgba(0, 0, 0, 0.2);}section .container .contactinfo h2{color: #fff;font-size: 24px;font-weight: 500;}section .container .contactinfo .info{position: relative;margin: 20px 0;}section .container .contactinfo .info li{position: relative;list-style: none;display: flex;margin: 20px 0;cursor: pointer;align-items: flex-start;}section .container .contactinfo .info li span:nth-child(1){width: 30px;min-width: 30px;}section .container .contactinfo .info li span:nth-child(1) img{max-width: 100%;filter: invert(1);opacity: 0.5;}section .container .contactinfo .info li span:nth-child(2){color: #fff;margin-left: 10px;font-weight: 300;opacity: 0.5;}section .container .contactinfo .info li:hover span:nth-child(1) img,section .container .contactinfo .info li:hover span:nth-child(2){opacity: 1;}section .container .contactinfo .sci{position: relative;display: flex;}section .container .contactinfo .sci li{list-style: none;margin-right: 15px;}section .container .contactinfo .sci li a{text-decoration: none;}section .container .contactinfo .sci li a img{filter: invert(1);opacity: 0.5;}section .container .contactinfo .sci li:hover a img{opacity: 1;}section .container .contactForm{position: absolute;padding: 70px 50px;background: #fff;margin-left: 150px;padding-left: 250px;width: calc(100% - 150px);height: 100%;box-shadow: 0 50px 50px rgba(0,0,0,0.5);}section .container .contactForm h2{color: #0f3959;font-size: 24px;font-weight: 500;}section .container .contactForm .formBox{position: relative;display: flex;justify-content: space-between;flex-wrap: wrap;padding-top: 30px;}section .container .contactForm .formBox .inputBox{position: relative;margin: 0 0 35px 0;}section .container .contactForm .formBox .inputBox.w50{width: 47%;}section .container .contactForm .formBox .inputBox.w100{width: 100%;}section .container .contactForm .formBox .inputBox input,section .container .contactForm .formBox .inputBox textarea{width: 100% !important;padding: 5px 0;resize: none;font-size: 18px;font-weight: 300;color: #333;border: none;border-bottom: 1px solid #777;outline: none;}section .container .contactForm .formBox .inputBox textarea{min-height: 120px;}section .container .contactForm .formBox .inputBox span{position: absolute;left: 0;padding: 5px 0;font-size: 18px;font-weight: 300;color: #333;transition: 0.3s;pointer-events: none;}section .container .contactForm .formBox .inputBox input:focus ~ span,section .container .contactForm .formBox .inputBox textarea:focus ~ span,section .container .contactForm .formBox .inputBox input:valid ~ span,section .container .contactForm .formBox .inputBox textarea:valid ~ span{transform: translateY(-20px);font-size: 12px;font-weight: 400;letter-spacing: 1px;color: #ff568c;}section .container .contactForm .formBox .inputBox input[type="submit"]{position: relative;cursor: pointer;background: #0f3959;color: #fff;border: none;max-width: 150px;padding: 12px;}section .container .contactForm .formBox .inputBox input[type="submit"]:hover{background: #ff568c;}