来画个皮卡丘吧

JS的作用：

1. 操作DOM
2. 操作AJAX
3. 其他

一个项目60%的时间在写CSS，20%的时间在写JS, 20%的时间在想自己错在哪儿

材料来源：
codepen:https://codepen.io/

将body的font-size设为100px, 则其他的地方的单位用em就很好换算了

鼻子

做一个钝角三角形

要点：让border-width不同

.nose {
    width:0;
    height:0;
    border-top: 9px solid red;
    border-left: 11px solid transparent;
    border-right: 11px solid transparent;
}

在三角形上加半个椭圆

要点：用x,y轴半径构成椭圆

.nose::before {
    content: '';
    display: block;
    width: 22px;
    height: 5px;
    background: black;
    position: absolute;
    top: -14px;
    left:-11px;
    border-top-right-radius: 11px 5px;   /* 椭圆 x y 轴半径: x=width/2 y=height */
    border-top-left-radius: 11px 5px;
    box-shadow: 0 -.5px 1px black;
}

眼睛

要点：先居中，然后用transform移到两边

.eye {
    border: 3px solid black;
    width: 64px;
    height: 64px;
    position: absolute;
    left: 50%;
    top: 165px;
    margin-left: -32px;
    border-radius: 50%;
    background:#2e2e2e;
}
.eye.left {
    transform: translateX(-110px);   /* 让眼睛在鼻子两边 */
}
.eye.right {
    transform: translateX(110px);
}
.eye::before{
    content: '';
    display: block;
    width: 32px;
    height: 32px;
    border: 3px solid black;
    background: white;
    border-radius: 50%;
    position: relative;
    left: 6px;
    top: -2px;
}

上嘴唇

要点：用translateZ(0)去除rotate产生的边框

.up {
    width: 160px;
    height: 100px;
    position: absolute;
    left: 50%;
    top: 220px;
    margin-left: -80px;
}
.up .lip {
    background: #ffe600;
    width: 80px;
    height: 30px;
    position: absolute;
}
.up .lip.left{ 
    border-left: 3px solid black;
    border-bottom: 3px solid black; 
    border-bottom-left-radius: 55px 30px;   
    transform: rotate(-25deg) translateZ(0);  /* 用GPU渲染，去除锯齿边框 */
    left: -1.5px;
}
.up .lip.right{
    border-right: 3px solid black;
    border-bottom: 3px solid black; 
    border-bottom-right-radius: 55px 30px;
    transform: rotate(25deg) translateZ(0); 
    right: -1.5px;
}

下嘴唇

要点： 用 overflow:hidden 隐藏超出盒子的内容

.down {
    width: 140px;
    height: 170px;
    position: absolute;
    left: 50%;
    margin-left: -70px;
    top: 232px;
    overflow: hidden;
    z-index: -1;
}
.down .inner {
    width: 180px;
    height: 900px;
    border: 4px solid black;
    background: #9b000a;
    position: absolute;
    bottom: 0;
    left: 50%;
    margin-left: -90px;
    border-bottom-left-radius: 100%;
    border-bottom-right-radius: 100%;
    overflow: hidden;
}
.down .inner .outer {
    width: 200px;
    height: 500px;
    background: #ff485f;
    position: absolute;
    bottom: -360px;
    left: 50%;
    margin-left: -100px;
    border-top-left-radius: 95px 150px;
    border-top-right-radius: 95px 150px;
}

鼻子动画

要点：transform-origin设置变形的原点

@keyframes move {
    0% {transform: rotate(0)}
    33% {transform: rotate(4deg)}
    66% {transform: rotate(-4deg)}
    100% {transform: rotate(0)}
}
.nose:hover {
    transform-origin: center bottom;
    animation: move 100ms infinite;
}

眼球转动效果

@keyframes eyes-move {
    0%,20% {top: -1px; left: 7px;}
    5% {top: 5px; left: 25px;}
    10% {top: 20px; left: 29px;}
    15% {top: 25px; left: 5px;}
}
.eye::before {
  animation: eyes-move 4s infinite linear;
}

眨眼效果

通过移动位于眼睛上方与背景同色的div来实现
也可以用opacity调整透明度来实现，1表示不透明，0表示透明

@keyframes eye-close {
    0%, 23%, 33%, 100% {top: -100px;}
    28% {top: -55px;}
}
.eye::after {
    content: '';
    display: block;
    width: 66px;
    height: 66px;
    position: relative;
    top: -100px;
    left: -4px;
    background: #ffe600;
    animation: eye-close 4s infinite linear;
}

颜色渐变淡出效果

要点：ease-out

.cheek {
animation: light 4s ease-out infinite;
}
@keyframes light {
    55% {background: #ff0000;}
    60% {background: #FFFA3F;} 
}