Summary of shadow effects implemented by the box-shadow attribute in CSS3

This article brings you a summary of the shadow effect achieved by the box-shadow attribute in CSS3. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

CSS3 box-shadow property is used to describe one or more shadow effects of an element. This property allows you to achieve almost any shadow effect you want. However, the box-shadow attribute syntax and value are very flexible, which is a bit difficult for novices to understand. Today we will summarize the syntax and various shadow effects of the box-shadow attribute.

Syntax

/* offset-x | offset-y | color */
box-shadow: 60px -16px teal;
/* offset-x | offset-y | blur-radius | color */
box-shadow: 10px 5px 5px black;
/* offset-x | offset-y | blur-radius | spread-radius | color */
box-shadow: 2px 2px 2px 1px rgba(0, 0, 0, 0.2);
/* inset | offset-x | offset-y | color */
box-shadow: inset 5em 1em gold;
/* Any number of shadows, separated by commas */
box-shadow: 3px 3px red, -1em 0 0.4em olive;
/* Global keywords */
box-shadow: inherit;
box-shadow: initial;
box-shadow: unset;

Value description:

inset: The default shadow is outside the border. After using inset, the shadow is within the border (even a transparent border), above the background and below the content. Some people also like to put this value at the end, and browsers also support it.

: These are the first two values, used to set the shadow offset. sets the horizontal offset. If it is a negative value, the shadow will be on the left side of the element. sets the vertical offset. If it is a negative value, the shadow will be positioned above the element. See for available units. If both are 0, then the shadow is behind the element. At this time, if or is set, there will be a blur effect.

: This is the third value. The larger the value, the larger the blur area and the larger and lighter the shadow. Cannot be a negative value. The default is 0, in which case the shadow edges are sharp.

: This is the fourth value. When taking a positive value, the shadow expands; when taking a negative value, the shadow shrinks. The default is 0, in which case the shadow is as large as the element.

: See related matters . If not specified, it is determined by the browser - usually the value of color, but Safari currently uses transparent.

I found a few pictures on the Internet. You can look at them accordingly to make it easier to understand.

Let’s be more specific:

div {
    width: 150px;
    height: 150px;
    background-color: #fff;
    
    box-shadow: 120px 80px 40px 20px #0ff;
    /* 顺序为: offset-x, offset-y, blur-size, spread-size, color */
    /* blur-size 和 spread-size 是可选的 (默认为 0) */
}

Here’s a diagram:

The simplest general effect

The following are some of the simplest shadow effects, which should be very easy to understand by looking at the code:

HTML

<div class="flex">
  <div class="flex-item">
    <h3 id="内阴影示例">内阴影示例</h3>
    <div class="box boxshadow1"></div>
  </div>
  <div class="flex-item">
    <h3 id="边内影示例">3边内影示例</h3>
    <div class="box boxshadow2"></div>
  </div>
  <div class="flex-item">
    <h3 id="外阴影示例">外阴影示例</h3>
    <div class="box boxshadow3"></div>
  </div>
  <div class="flex-item">
    <h3 id="右下外阴影示例">右下外阴影示例</h3>
    <div class="box boxshadow4"></div>
  </div>
  <div class="flex-item">
    <h3 id="扩大阴影示例">扩大阴影示例</h3>
    <div class="box boxshadow5"></div>
  </div>
  <div class="flex-item">
    <h3 id="半透明阴影色示例">半透明阴影色示例</h3>
    <div class="box boxshadow6"></div>
  </div>
</div>

CSS

.flex{display:flex;flex-wrap:wrap;} 
.flex-item{margin-right:30px;}

.box {  background-color: #CCCCCC; border-radius:10px; width: 200px; height: 200px;  }
.boxshadow1{ box-shadow:inset 0px 0px 5px 1px #000; }
.boxshadow2{ box-shadow:inset 0 1px 2px 1px #000; }
.boxshadow3{box-shadow:0 0 10px #000;}
.boxshadow4{box-shadow:2px 2px 5px #000;}
.boxshadow5{box-shadow:0 0 5px 15px #000;}
.boxshadow6{box-shadow: 12px 12px 2px 1px rgba(0, 0, 255, .2);}

The effect is as follows

##Single Edge shadow effect

The single edge shadow effect can create some effects, such as strokes, small shadows in special scenes, and some transition colors.

HTML

<div class="flex">
  <div class="flex-item">
    <h3 id="上边内阴影示例">上边内阴影示例</h3>
    <div class="box boxshadow1"></div>
  </div>
  <div class="flex-item">
    <h3 id="右边内阴影示例">右边内阴影示例</h3>
    <div class="box boxshadow2"></div>
  </div>
  <div class="flex-item">
    <h3 id="下边外阴影示例">下边外阴影示例</h3>
    <div class="box boxshadow3"></div>
  </div>
  <div class="flex-item">
    <h3 id="右边外阴影示例">右边外阴影示例</h3>
    <div class="box boxshadow4"></div>
  </div>
  <div class="flex-item">
    <h3 id="下边细线示例">下边细线示例</h3>
    <div class="box boxshadow5"></div>
  </div>
</div>

CSS

.flex{display:flex;flex-wrap:wrap;} 
.flex-item{margin-right:30px;}

.box {  background-color: #CCCCCC;  width: 200px; height: 200px;  }
.boxshadow1{ box-shadow:inset 0px 15px 10px -15px #000; }
.boxshadow2{ box-shadow:inset -15px 0px  10px -15px #000;}
.boxshadow3{box-shadow:0px 12px 8px -12px #000; border-radius:10px; }
.boxshadow4{box-shadow:3px 0 8px -4px #000;}
.boxshadow5{ box-shadow: inset 0px -1px 0px 0px rgb(0, 0, 0) ;}

The effect is as follows

##Bilateral Shadow and multiple shadow effects

HTML

<div class="flex">
  <div class="flex-item">
    <h3 id="上下边内阴影示例">上下边内阴影示例</h3>
    <div class="box boxshadow1"></div>
  </div>
  
  <div class="flex-item">
    <h3 id="左右边外阴影示例">左右边外阴影示例</h3>
    <div class="box boxshadow2"></div>
  </div>
  <div class="flex-item">
    <h3 id="多层阴影示例">多层阴影示例</h3>
    <div class="box boxshadow3"></div>
  </div>
</div>

CSS

.flex{display:flex;flex-wrap:wrap;} 
.flex-item{margin-right:30px;}

.box {  background-color: #CCCCCC;  width: 200px; height: 200px;  }

.boxshadow1{ 
  box-shadow:inset 0px 15px 15px -15px #000,
             inset 0px -15px 15px -15px #000; 
}
.boxshadow2{ 
  box-shadow:15px 0 15px -15px #000,
             -15px 0 15px -15px #000;
}
.boxshadow3{ border-radius:10px; 
  box-shadow:0px 0px 0px 3px #bb0a0a,
             0px 0px 0px 6px #2e56bf,
             0px 0px 0px 9px #ea982e;
}

The effect is as follows

Some other interesting shadows:

Using the pseudo-elements ::before and ::after, we can create very realistic shadow effects that only pictures can achieve. Let me look at an example:

HTML

<div class="box11 shadow"></div>

CSS

.box11 {
	width: 300px;
	height: 100px;
	background: #ccc;
	border-radius: 10px;
	margin: 10px;
}

.shadow {
	position: relative;
	max-width: 270px;
	box-shadow: 0px 1px 4px rgba(0,0,0,0.3),
				0px 0px 20px rgba(0,0,0,0.1) inset;
}

.shadow::before,
.shadow::after {
   content:"";
   position:absolute;
   z-index:-1;
}

.shadow::before,
.shadow::after {
   content:"";
   position:absolute;
   z-index:-1;
   bottom:15px;
   left:10px;
   width:50%;
   height:20%;
}

.shadow::before,
.shadow::after {
   content:"";
   position:absolute;
   z-index:-1;
   bottom:15px;
   left:10px;
   width:50%;
   height:20%;
   box-shadow:0 15px 10px rgba(0, 0, 0, 0.7);
   transform:rotate(-3deg);
}

.shadow::after{
   right:10px;
   left:auto;
   transform:rotate(3deg);
 }

The effect is as follows

Come again Some effects:

HTML

<div class="wrap">
  <div class="box box1 shadow1">
    <h3 id="Shadow-nbsp">Shadow 1</h3>
  </div>
  <div class="box box2 shadow2">
    <h3 id="Shadow-nbsp">Shadow 2</h3>
  </div>
  <div class="box box3 shadow3">
    <h3 id="Shadow-nbsp">Shadow 3</h3>
  </div>
  <div class="box box4 shadow4">
    <h3 id="Shadow-nbsp">Shadow 4</h3>
  </div>
  <div class="box box5 shadow5">
    <h3 id="Shadow-nbsp">Shadow 5</h3>
  </div>
  <div class="box box6 shadow6">
    <h3 id="Shadow-nbsp">Shadow 6</h3>
  </div>
  <div class="box box7 shadow7">
    <h3 id="Shadow-nbsp">Shadow 7</h3>
  </div>
  <div class="box box8 shadow8">
    <h3 id="Shadow-nbsp">Shadow 8</h3>
  </div>
</div>

CSS

body{
  background:#E6EEF6;
}
.wrap{
  margin-left:20px;
}
.box{
  width:40%;
  height:200px;
  float:left;
  background-color:white; 
  margin:25px 15px;
  border-radius:5px;
}
.box h3{
  font-family: 'Didact Gothic', sans-serif;
  font-weight:normal;
  text-align:center;
  padding-top:60px;
  color:#fff;
}
.box1{
  background-color: #EBA39E;
}
.box2{
  background-color: #EDE89A;
}
.box3{
  background-color: #9EEBA1;
}
.box4{
  background-color: #9EEBBF;
}
.box5{
  background-color: #9ED9EB;
}
.box6{
  background-color: #9EB3EB;
}
.box7{
  background-color: #DB9EEB;
}
.box8{
  background-color: #C49EEB;
}
.shadow1, .shadow2, .shadow3,.shadow4,.shadow5,.shadow6,.shadow7,.shadow8{
  position:relative;
}
.shadow1,.shadow2,.shadow3,.shadow4,.shadow5,.shadow6,.shadow7,.shadow8{
    box-shadow:0 1px 4px rgba(0, 0, 0, 0.3), 0 0 20px rgba(0, 0, 0, 0.1) inset;
}
/*****************************************************************dashed border
****************************************************************/
.shadow1 h3, .shadow2 h3, .shadow3 h3, .shadow4 h3, .shadow5 h3, .shadow6 h3, .shadow7 h3, .shadow8 h3{
  width:87%;
  height:100px;
  margin-left:6%;
  border:2px dashed #F7EEEE;
  border-radius:5px;
}
/****************************************************************
*styling shadows
****************************************************************/
.shadow1:before, .shadow1:after{
  position:absolute;
  content:"";
  bottom:12px;left:15px;top:80%;
  width:45%;
  background:#9B7468;
  z-index:-1;
  -webkit-box-shadow: 0 20px 15px #9B7468;
  -moz-box-shadow: 0 20px 15px #9B7468;
  box-shadow: 0 20px 15px #9B7468;
  -webkit-transform: rotate(-6deg);
  -moz-transform: rotate(-6deg);
  transform: rotate(-6deg);
}
.shadow1:after{
  -webkit-transform: rotate(6deg);
  -moz-transform: rotate(6deg);
  transform: rotate(6deg);
  right: 15px;left: auto;
}
.shadow2:before{
  position:absolute;
  content:"";
  width:80%;
  top:140px;bottom:15px;left:30px;
  background-color:#9F8641;
  z-index:-1;
  -webkit-box-shadow:0 23px 17px 0 #9F8641;
  -moz-box-shadow:0 23px 17px 0 #9F8641;
  box-shadow: 0 23px 17px 0 #9F8641;
  -webkit-transform:rotate(-4deg);
  -moz-transform:rotate(-4deg);
  transform:rotate(-4deg);
}
.shadow3:before, .shadow3:after{
  content:"";
  position:absolute;
  bottom:0;top:2px;left:15px;right:15px;
  z-index:-1;
  border-radius:100px/30px;
 -webkit-box-shadow:0 0 30px 2px #479F41;
  -moz-box-shadow:0 0 30px 2px #479F41;
  box-shadow: 0 0 30px 2px #479F41;
}
.shadow4:before, .shadow4:after{
  position:absolute;
  content:"";
  top:14px;bottom:14px;left:0;right:0;
  box-shadow:0 0 25px 3px #548E7F;
  border-radius:100px/10px;
  z-index:-1;
}
.shadow5:before, .shadow5:after{
  position:absolute;
  content:"";
  box-shadow:0 10px 25px 20px #518C96;
  top:40px;left:10px;bottom:50px;
  width:15%;
  z-index:-1;
  -webkit-transform: rotate(-8deg);
  -moz-transform: rotate(-8deg);
  transform: rotate(-8deg);
}
.shadow5:after{
  -webkit-transform: rotate(8deg);
  -moz-transform: rotate(8deg);
  transform: rotate(8deg);
  right: 10px;left: auto;
}
.shadow6:before, .shadow6:after{
  position:absolute;
  content:"";
  top:100px;bottom:5px;left:30px;right:30px;
  z-index:-1;
  box-shadow:0 0 40px 13px #486685;
  border-radius:100px/20px; 
}
.shadow7:before, .shadow7:after{
  position:absolute;
  content:"1";
  top:25px;left:20px;bottom:150px;
  width:80%;
  z-index:-1;
  -webkit-transform: rotate(-6deg);
  -moz-transform: rotate(-6deg);
  transform: rotate(-6deg);
}
.shadow7:before{
  box-shadow:10px -10px 30px 15px #984D8E;
}
.shadow7:after{
  -webkit-transform: rotate(7deg);
  -moz-transform: rotate(7deg);
  transform: rotate(7deg);
  bottom: 25px;top: auto;
  box-shadow:10px 10px 30px 15px #984D8E;
}
.shadow8{
  box-shadow:
 -6px -6px 8px -4px rgba(250,254,118,0.75),
  6px -6px 8px -4px rgba(254,159,50,0.75),
  6px 6px 8px -4px rgba(255,255,0,0.75),
  6px 6px 8px -4px rgba(0,0,255,2.75);
}

The effects are as follows

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