width : 가로

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title></title>
<style>
	div {border: 1px solid black;}
	div.test1 {width: auto;}
	div.test2 {width: 150px;}
	div.test3 {width: 50%;}
</style>
</head>
<body>
  <div class="test1">width: auto;</div>
  <div class="test2">width: 150px;</div>
  <div class="test3">width: 50%;</div>
</body>
</html>

heignt : 세로

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title></title>
<style>
	div {border: 1px solid black;}
	div.test1 {height: auto;}
	div.test2 {height: 150px;}
	div.test3 {height: 100px;}
	div.test4 {height: 50%;border: 1px solid red;}
</style>
</head>
<body>
  <div class="test1">hello world! hello world! hello world!
hello world! hello world! hello world!
hello world! hello world! hello world!
hello world! hello world! hello world!
hello world! hello world! hello world!
  </div>
  <div class="test2">height: 150px;</div>
  <div class="test3">
  	<div class="test4">height: 50%;border: 1px solid red;</div>
  </div>
</body>
</html>

padding : 안쪽 여백, margin : 바깥쪽 여백

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title></title>
<style>
	div.ex1 {
	  border: 1px solid red; 
	  padding: 35px;
	}
	div.ex2 {
	  border: 1px solid red; 
	  margin: 35px;
	}
</style>
</head>
<body>
	<div class="ex1">padding: 35px</div>
	<div class="ex2">margin: 35px</div>
</body>
</html>

margin : 세로 여백, margin 겹침

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title></title>
<style>
	div {
    	border: 1px solid red; 
        width : 200px;
    }
	div.ex1 {
	  margin : 10px 0;
	}
	div.ex2 {
	  margin : 10px auto;
	}
</style>
</head>
<body>
	<div class="ex1">세로 여백만 발생</div>
	<div class="ex2">세로 여백 발생, 가로 가운데 정렬</div>
	/*margin 겹침현상*/
	<div class="ex2">세로 여백 발생, 가로 가운데 정렬</div>
</body>
</html>

box-shadow : 그림자

<!DOCTYPE html>
<html>
<head>
<style> 
div {
	margin : 0 20px 30px 20px;
    border: 2px solid red;
  	padding: 5px;
    background-color:yellow;
}
#ex1 {
  box-shadow : 10px 10px gray;
}
#ex2 {
  box-shadow : 10px 10px 10px gray;
}
#ex3 {
  box-shadow : 10px 10px 10px 10px gray;
}
#ex4 {
  box-shadow : 10px 10px 10px 10px gray inset;
}
</style>
</head>
<body>
<div id="ex1">
  <p>box-shadow : 10px 10px gray</p>
</div>
<div id="ex2">
  <p>box-shadow : 10px 10px 10px gray</p>
</div>

<div id="ex3">
  <p>box-shadow : 10px 10px 10px 10px gray</p>
</div>

<div id="ex4">
  <p>box-shadow : 10px 10px 10px 10px gray inset</p>
</div>
</body>
</html>

box 변형

<!DOCTYPE html>
<html lang="ko">
<head><title> CSS3 </title>
<meta charset="utf-8" />
<style type="text/css">
h1 {  
  width:350px; 
  height:70px; 
  margin-bottom:20px; 
  border:3px solid #ccc;
  background-image: url("https://www.w3schools.com/cssref/paper.gif");
  background-color:brown;
}
.tra { 
  transform:translate(20px,-30px);
  -ms-transform:translate(20px,-30px); 
  -moz-transform:translate(20px,-30px); 
  -webkit-transform:translate(20px,-30px);
  -o-transform:translate(20px,-30px); 
}
.rot {
  transform:rotate(30deg);
  -ms-transform:rotate(30deg);
  -moz-transform:rotate(30deg);
  -webkit-transform:rotate(30deg);
  -o-transform:rotate(30deg);
}
.sca {
  transform:scale(1.3,0.7);
  -ms-transform:scale(1.3,0.7); /* IE 9 */
  -moz-transform:scale(1.3,0.7); /* Firefox */
  -webkit-transform:scale(1.3,0.7); /* Safari and Chrome */
  -o-transform:scale(1.3,0.7); /* Opera */
}
.ske { 
  transform:skew(30deg,20deg);
  -ms-transform:skew(30deg,20deg);
  -moz-transform:skew(30deg,20deg);
  -webkit-transform:skew(30deg,20deg);
  -o-transform:skew(30deg,20deg);
}
</style></head>

<body>
  <h1>원래박스</h1>
  <h1 class="tra">이동 : translate</h2>
  <h1 class="rot">회전 : rotate</h3>
  <h1 class="sca">크기 : scale</h4>
  <h1 class="ske">찌그러짐 : skew</h5>
</body>
</html>

box-sizing : 요소의 너비와 높이를 계산할시 여백과 테두리를 표함할지를 선택

<!DOCTYPE html>
<html>
<head>
<style> 
div {
  width: 300px;
  height: 100px;
  padding: 30px;  
  border: 10px solid blue;
  margin-bottom : 20px;
}
#example1 {
  box-sizing: content-box;  
}
#example2 {
  box-sizing: border-box;
}
</style>
</head>
<body>
<div id="example1">This div has a width of 300px. But the full width is 300px + 20px (left and right border) + 60px (left and right padding) = 380px!</div>
<div id="example2">Here, the full width is 300px, no matter what!</div>
</body>
</html>

resize : 박스의 모서리로 크기를 조정

<!DOCTYPE html>
<html>
<head>
<style> 
div {
  border: 2px solid;
  padding: 20px; 
  width: 300px;
  overflow: auto;
  margin-bottom : 30px;
}
div.ex1 {
  resize: none;
}
div.ex2 {
  resize: both;
}
div.ex3 {
  resize: horizontal;
}
div.ex4 {
  resize: vertical;
}
</style>
</head>
<body>
<div class="ex1">
  resize: none
</div>
<div class="ex2">
  resize: both
</div>
<div class="ex3">
  resize: horizontal
</div>
<div class="ex4">
  resize: vertical
</div>
</body>
</html>