lovecoding
/
Web1020


			
				
					
						
						
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							<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        input {
            /* border:none; */
            outline: none;
            outline: 3px solid red;
            outline-width: 1px;
            outline-style: dashed;
            outline-color: aqua;
        }
        .aa {
            width: 700px;
            height: 700px;
            background: #ff0;
            margin: 0 auto;
        }
        .one {
            width: 200px;
            height: 200px;
            /* 已知宽高的盒子在它的 父级内居中 */
            background: red;
            margin: 0 auto;
        }
        
    </style>
</head>
<body>
    <!-- 
        轮廓：outline
        border 边框
    -->
        <div class="aa">
            
        <div class="one"></div>
        </div>
    <!-- <input type="text"> -->
</body>
</html>