css3基础-选择器+边框与圆角+背景与渐变

2021-05-03 20:28

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标签：sid rtc char 倒数 pre 空格 repeat child 绘制

Css3选择器相关：

section > div直接子元素选择器

div + article相邻兄弟选择器（在元素之后出现）

div ~ article通用兄弟选择器（在元素之后出现）

属性选择器：

a[href] {
    text-decoration: none;
}
a[href=""] {
    color: #f00;
}
/*包含two且属性值用空格分隔：*/
a[class~="two"] {
    color: #ff0;
}
/*属性的第一个值以#开头：*/
a[href^="#"] {
    color: #0f0;
}
/*以#结尾：*/
a[href$="#"] {
    color: #00f;
}
/*包含#：*/
a[href*="#"] {
    color: #0ff;
}
/*第一个属性值以#-开头：*/
a[href|="#"] {
    color: #f0f;
}

UI元素伪类：

Input:disabled

Input:enabled

Input:checked

div:first-child匹配属于其父元素的第1个子元素且是div，计数时不分类型，显示时分类型

div:last-child匹配属于其父元素的最后1个子元素且是div，计数时不分类型，显示时分类型div:nth-child(2) 匹配属于其父元素的第n个子元素且是div，计数时不分类型，显示时分类型div:nth-lat-child(2) 匹配属于其父元素的第n个子元素且是div，计数时不分类型，显示时分类型

n匹配下标，从0开始计算：

li:nth-child(2n) 双数

li:nth-child(2n+1) 单数

li:nth-child(n+4)

li:nth-child(odd) 奇数，下标从1开始计算

li:nth-child(even) 偶数，下标从1开始计算

li:nth-last-child(3) 倒数第3个

article:only-child 属于父元素的唯一元素，且是article(没有任何其他子元素)

div:nth-of-type(2) 匹配属于其父元素的第2个子元素且是div，计数时分类型

div:nth-last-of-type(2)

div:first-of-type div:last-of-type

article:only-of-type 属于父元素的唯一article元素（可以有其他类型的子元素）

div:empty 没有子元素的div元素（包括文本也没有）

a:not(:last-of-type) 不是最后一个a子元素

id选择器权重大于属性选择器

.red > [class=”red”]

Css伪元素：

div::selection 文本被选中后的样式

::-moz-selection 火狐

Css3边框与圆角：

四个值按照顺时针方向来

Border-radius兼容性写法：

-webkit-border-radius: 50%;
       -moz-border-radius: 50%;
        -ms-border-radius: 50%;
         -o-border-radius: 50%;
            border-radius: 50%;

box-shadow水平偏移垂直偏移模糊扩展颜色内部

box-shadow: 50px 30px 0px 0px yellow inset;

border-image-repeat:stretch（拉伸）/repeat（重复）/round（铺满）/initial/inherit

border-image-source: url("border.jpg");
    border-image-slice: 50%;/*图像边界向内偏移*/
    border-image-width: 50%;/*图像边界的宽度*/
    border-image-outset: 2; /*在边框外部绘制*/
    border-image-repeat: repeat;

css3背景与渐变：

背景绘制区域（显示范围）

background-clip: border-box;
background-clip: padding-box;
background-clip: content-box;

背景图像定位（起始位置，原点位置，与偏移搭配使用）

background-origin: border-box;
background-origin: padding-box;
background-origin: content-box;
background-position:10px 10px; /*与偏移搭配使用*/

background-size只写一个值，第二个默认是auto，根据比例等比缩放

background-size: contain; /*等比缩放到某一边达到容器边缘*/
background-size: cover;/*等比缩放填满容器*/
background-size: 800px 500px;
background-size: 800px;
background-size: 50% 50%;
background-size: 50%;
background-size: 100% 100%;
background-size: 100%;

background-image多重背景，前面的会覆盖后面的

background-image: url(‘bg2.png‘), url(‘bg1.jpg‘);

demo：

DOCTYPE html>
html>
head>
    meta charset="UTF-8">
    title>background-imagetitle>
    style type="text/css">
        div{
            width:300px;
            height:300px;
            background:url(1.jpg) no-repeat center top,
            url(2.jpg) no-repeat center 100px,
            url(3.jpg) no-repeat center 200px;
            margin:0 auto;
        }
    style>
head>
body>
    div>div>
body>
html>

技术图片

默认从上到下渐变：

div {
    width: 800px; height: 500px;
    background: -webkit-linear-gradient(red, blue);
    background:    -moz-linear-gradient(red, blue);
    background:      -o-linear-gradient(red, blue);
    background:         linear-gradient(red, blue);
}

从左到右渐变

div {
    width: 800px; height: 500px;
    background: -webkit-linear-gradient(left, red , blue);
    background:    -moz-linear-gradient(right, red, blue);
    background:      -o-linear-gradient(right, red, blue);
    background:         linear-gradient(to right, red , blue);
}

左上角开始的对角线渐变

div {
    width: 800px; height: 500px;
    background: -webkit-linear-gradient(       left top, red, yellow, blue);
    background:    -moz-linear-gradient(   right bottom, red, yellow, blue);
    background:      -o-linear-gradient(   right bottom, red, yellow, blue);
    background:         linear-gradient(to right bottom, red, yellow, blue);
}

角度控制方向

角度渐变是水平线和渐变线之间的角度，0deg是从下到上，90度是从左到右

div {
    width: 800px; height: 500px;
    background: -webkit-linear-gradient(135deg, red, yellow, blue);
    background:    -moz-linear-gradient(135deg, red, yellow, blue);
    background:      -o-linear-gradient(135deg, red, yellow, blue);
    background:         linear-gradient(135deg, red, yellow, blue);
}

渐变具体位置控制

div {
    width: 800px; height: 500px;
    background: -webkit-linear-gradient(90deg, red 10%, orange 15%, yellow 20%, green 50%, blue 70%, indigo 80%, violet 100%);
    background:    -moz-linear-gradient(90deg, red 10%, orange 15%, yellow 20%, green 50%, blue 70%, indigo 80%, violet 100%);
    background:      -o-linear-gradient(90deg, red 10%, orange 15%, yellow 20%, green 50%, blue 70%, indigo 80%, violet 100%);
    background:         linear-gradient(90deg, red 10%, orange 15%, yellow 20%, green 50%, blue 70%, indigo 80%, violet 100%);
}

透明色渐变

div {
    width: 800px; height: 500px;
    background: -webkit-linear-gradient(90deg, rgba(255, 0, 0, 0), rgba(255, 0, 0, 1));
    background:    -moz-linear-gradient(90deg, rgba(255, 0, 0, 0), rgba(255, 0, 0, 1));
    background:      -o-linear-gradient(90deg, rgba(255, 0, 0, 0), rgba(255, 0, 0, 1));
    background:         linear-gradient(90deg, rgba(255, 0, 0, 0), rgba(255, 0, 0, 1));
}

重复渐变

div {
    width: 800px; height: 500px;
    background: -webkit-repeating-linear-gradient(90deg, red 0%, blue 10%, red 20%);
    background:    -moz-repeating-linear-gradient(90deg, red 0%, blue 10%, red 20%);
    background:      -o-repeating-linear-gradient(90deg, red 0%, blue 10%, red 20%);
    background:         repeating-linear-gradient(90deg, red 0%, blue 10%, red 20%);
}

径向渐变，从内到外

div {
    width: 800px; height: 500px;
    background: -webkit-radial-gradient(red, blue);
    background:    -moz-radial-gradient(red, blue);
    background:      -o-radial-gradient(red, blue);
    background:         radial-gradient(red, blue);
}

圆形渐变

div {
    width: 800px; height: 500px;
    background: -webkit-radial-gradient(circle, red, blue);
    background:    -moz-radial-gradient(circle, red, blue);
    background:      -o-radial-gradient(circle, red, blue);
    background:         radial-gradient(circle, red, blue);
}

椭圆形渐变

div {
    width: 800px; height: 500px;
    background: -webkit-radial-gradient(ellipse, red, blue);
    background:    -moz-radial-gradient(ellipse, red, blue);
    background:      -o-radial-gradient(ellipse, red, blue);
    background:         radial-gradient(ellipse, red, blue);
}

渐变从圆心到最近边

div.closest-side {
    width: 300px; height: 200px; margin: 50px;
    background: -webkit-radial-gradient(30% 70%, circle closest-side, red, blue);
    background:    -moz-radial-gradient(30% 70%, circle closest-side, red, blue);
    background:      -o-radial-gradient(30% 70%, circle closest-side, red, blue);
    background:         radial-gradient(30% 70%, circle closest-side, red, blue);
}

渐变从圆心到最远边

div.farthest-side {
    width: 300px; height: 200px; margin: 50px;
    background: -webkit-radial-gradient(30% 70%, farthest-side, red, blue);
    background:    -moz-radial-gradient(30% 70%, farthest-side, red, blue);
    background:      -o-radial-gradient(30% 70%, farthest-side, red, blue);
    background:         radial-gradient(30% 70%, farthest-side, red, blue);
}

渐变从圆心到最近角

div.closest-corner {
    width: 300px; height: 200px; margin: 50px;
    background: -webkit-radial-gradient(30% 70%, closest-corner, red, blue);
    background:    -moz-radial-gradient(30% 70%, closest-corner, red, blue);
    background:      -o-radial-gradient(30% 70%, closest-corner, red, blue);
    background:         radial-gradient(30% 70%, closest-corner, red, blue);
}

渐变从圆心到最远角

div.farthest-corner {
    width: 300px; height: 200px; margin: 50px;
    background: -webkit-radial-gradient(30% 70%, farthest-corner, red, blue);
    background:    -moz-radial-gradient(30% 70%, farthest-corner, red, blue);
    background:      -o-radial-gradient(30% 70%, farthest-corner, red, blue);
    background:         radial-gradient(30% 70%, farthest-corner, red, blue);
}

IE渐变从上到下

div {
    width: 800px;
    height: 500px;
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr=‘#ff0000‘, endColorstr=‘#0000ff‘,GradientType=0 );
}

IE渐变从左到右

div {
    width: 800px;
    height: 500px;
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr=‘#ff0000‘, endColorstr=‘#0000ff‘,GradientType=1 );
}

Demo：

DOCTYPE html>
html lang="en">
head>
meta charset="UTF-8">
title>线性渐变 - 特殊案例title>
style type="text/css">
div {
    width: 800px; height: 500px; background: #abcdef; background-size: 50px 50px;
    background-image:
        -webkit-gradient(linear, 0 0, 100% 100%, color-stop(.25, #555), color-stop(.25, transparent), to(transparent)),
        -webkit-gradient(linear, 0 100%, 100% 0, color-stop(.25, #555), color-stop(.25, transparent), to(transparent)),
        -webkit-gradient(linear, 0 0, 100% 100%, color-stop(.75, transparent), color-stop(.75, #555)),
        -webkit-gradient(linear, 0 100%, 100% 0, color-stop(.75, transparent), color-stop(.75, #555));
    background-image:
        -moz-linear-gradient(45deg, #555 25%, transparent 25%, transparent),
        -moz-linear-gradient(-45deg, #555 25%, transparent 25%, transparent),
        -moz-linear-gradient(45deg, transparent 75%, #555 75%),
        -moz-linear-gradient(-45deg, transparent 75%, #555 75%);
    background-image:
        -o-linear-gradient(45deg, #555 25%, transparent 25%, transparent),
        -o-linear-gradient(-45deg, #555 25%, transparent 25%, transparent),
        -o-linear-gradient(45deg, transparent 75%, #555 75%),
        -o-linear-gradient(-45deg, transparent 75%, #555 75%);
    background-image:
        linear-gradient(45deg, #555 25%, transparent 25%, transparent),
        linear-gradient(-45deg, #555 25%, transparent 25%, transparent),
        linear-gradient(45deg, transparent 75%, #555 75%),
        linear-gradient(-45deg, transparent 75%, #555 75%);
}
style>
head>
body>
div>div>
body>
html>