我正在尝试为我的网站创建"ribbon"标题。
到目前为止，这就是我所能模拟的。
这适用于短标题(对于short的某些值(，但当标题想要换行时会失败。是否可以使用创建"燕尾"形状的边界方法，但使:after伪元素的边界宽度与父元素的高度相关，而不是在不使用脚本的情况下进行硬编码？
是否有其他方法可以实现类似的视觉效果？
html, body, div { margin: 0; }
body { background: lightgrey; }
.wrapper {
background: white;
padding: 2em;
padding-top: 0;
margin: 2em;
margin: 2em auto;
width: 80%;
}
.ribbon {
font-size: 32px;
line-height: 1.5em;
display: inline-block;
font-family: Optima;
color: white;
background: #9c0000;
margin: 0;
position: relative;
width: 100%;
padding: 1em;
padding-left: 1.5em;
left: -1.5em;
filter: drop-shadow(5px 5px 3px grey);
-webkit-filter: drop-shadow(5px 5px 3px grey);
-moz-filter: drop-shadow(5px 5px 3px grey);
margin-top: 1em;
box-decoration-break: clone;
-webkit-box-decoration-break: clone;
}
.ribbon-bot:before {
position: absolute;
height: 0;
width: 0;
content: "";
border-color: red green blue yellow;
border-color: #4d0000 #4d0000 transparent transparent;
border-style: solid;
border-width: 0.1em 0.25em 0.1em 0.25em;
left: 0em;
bottom: -0.199375em;
}
.ribbon-top:before {
position: absolute;
height: 0;
width: 0;
content: "";
border-color: transparent #4d0000 #4d0000 transparent;
border-style: solid;
border-width: 0.1em 0.25em 0.1em 0.25em;
left: 0em;
top: -0.199375em;
}
.ribbon:after {
position: absolute;
width: 0;
right: -20px;
bottom: 0px;
content: "";
border-color: #9c0000 transparent #9c0000;
border-width: 1.75em 20px 1.75em 0;
border-style: solid;
z-index: -1;
}<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>
<div class="wrapper">
<div class="ribbon ribbon-bot">Ribbon</div>
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut non mi libero. Nam
ultrices malesuada nulla, eu faucibus eros. Nulla non est odio. Maecenas
vulputate nec sem vitae viverra. In vitae dapibus purus. Morbi mattis mi nulla,
sed iaculis justo mollis et. Integer porttitor augue nisl, ac auctor nisl
posuere vitae. Praesent at ligula fermentum, maximus mi ac, vehicula mi. Nam
ligula mi, suscipit id dictum nec, varius sagittis nisl. Lorem ipsum dolor sit
amet, consectetur adipiscing elit. Suspendisse consequat ipsum a nibh imperdiet
interdum.</p>
<div class="ribbon ribbon-top">A Moderately Long Heading Goes Here A Moderately Long Heading Goes Here</div>
<p>Donec venenatis ante tellus, venenatis consectetur arcu sagittis at. Phasellus
eu neque a dolor porta rutrum et ac lorem. Nulla ornare nisl quis est lacinia
vehicula. Sed elementum ante elit, interdum porta elit tristique ac. Praesent
felis dolor, luctus elementum nisi non, vehicula aliquet mauris. Vestibulum
fermentum erat nibh, in facilisis lorem bibendum sed. Phasellus condimentum
pharetra quam, et placerat massa auctor nec. Mauris fringilla hendrerit lectus,
nec congue elit semper tempus. Pellentesque convallis interdum ligula, et
faucibus nulla vulputate eget. Donec mattis orci at leo fringilla mollis.</p>
</div>
</body>
</html>我会使用渐变创建相同的形状，它会像你想要的那样响应：
html, body, div { margin: 0; }
body { background: lightgrey; }
.wrapper {
background: white;
padding: 2em;
padding-top: 0;
margin: 2em;
margin: 2em auto;
width: 80%;
}
.ribbon-bot,
.ribbon-top{
font-size: 32px;
line-height: 1.5em;
display: inline-block;
color: white;
background:
/*the small triangl at the bottom left*/
linear-gradient(to bottom left, #4d0000 49%,transparent 50%) bottom left/15px 12px,
/*the 2 triangle shape at the left*/
linear-gradient(to top right, #9c0000 49%,transparent 50%) 100% calc(100% - 12px)/20px calc(50% - 6px),
linear-gradient(to bottom right,#9c0000 49%,transparent 50%) right top/20px calc(50% - 6px),
/*the main part*/
linear-gradient(#9c0000,#9c0000) left top/calc(100% - 20px) calc(100% - 12px);
background-repeat:no-repeat;
position: relative;
width: 100%;
padding: 1em;
padding-left: 1.5em;
left: -1.5em;
filter: drop-shadow(5px 5px 3px grey);
margin-top: 1em;
}
.ribbon-top {
background:
linear-gradient(to top left, #4d0000 49%,transparent 50%) top left/15px 12px,
linear-gradient(to top right,#9c0000 49%,transparent 50%) bottom right /20px calc(50% - 6px),
linear-gradient(to bottom right,#9c0000 49%,transparent 50%) 100% 12px/20px calc(50% - 6px),
linear-gradient(#9c0000,#9c0000) left bottom/calc(100% - 20px) calc(100% - 12px);
background-repeat:no-repeat;
}<div class="wrapper">
<div class="ribbon-bot">Ribbon</div>
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut non mi libero. Nam
ultrices malesuada nulla, eu faucibus eros. Nulla non est odio. Maecenas
vulputate nec sem vitae viverra. In vitae dapibus purus. Morbi mattis mi nulla,
sed iaculis justo mollis et. Integer porttitor augue nisl, ac auctor nisl
posuere vitae. Praesent at ligula fermentum, maximus mi ac, vehicula mi. Nam
ligula mi, suscipit id dictum nec, varius sagittis nisl. Lorem ipsum dolor sit
amet, consectetur adipiscing elit. Suspendisse consequat ipsum a nibh imperdiet
interdum.</p>
<div class="ribbon-top">A Moderately Long Heading Goes Here A Moderately Long Heading Goes Here</div>
<p>Donec venenatis ante tellus, venenatis consectetur arcu sagittis at. Phasellus
eu neque a dolor porta rutrum et ac lorem. Nulla ornare nisl quis est lacinia
vehicula. Sed elementum ante elit, interdum porta elit tristique ac. Praesent
felis dolor, luctus elementum nisi non, vehicula aliquet mauris. Vestibulum
fermentum erat nibh, in facilisis lorem bibendum sed. Phasellus condimentum
pharetra quam, et placerat massa auctor nec. Mauris fringilla hendrerit lectus,
nec congue elit semper tempus. Pellentesque convallis interdum ligula, et
faucibus nulla vulputate eget. Donec mattis orci at leo fringilla mollis.</p>
</div>另一种方法是保留代码并将clip-path与:after伪元素一起使用：
html, body, div { margin: 0; }
body { background: lightgrey; }
.wrapper {
background: white;
padding: 2em;
padding-top: 0;
margin: 2em;
margin: 2em auto;
width: 80%;
}
.ribbon {
font-size: 32px;
line-height: 1.5em;
display: inline-block;
font-family: Optima;
color: white;
background: #9c0000;
margin: 0;
position: relative;
width: 100%;
padding: 1em;
padding-left: 1.5em;
left: -1.5em;
filter: drop-shadow(5px 5px 3px grey);
-webkit-filter: drop-shadow(5px 5px 3px grey);
-moz-filter: drop-shadow(5px 5px 3px grey);
margin-top: 1em;
box-decoration-break: clone;
-webkit-box-decoration-break: clone;
}
.ribbon-bot:before {
position: absolute;
height: 0;
width: 0;
content: "";
border-color: #4d0000 #4d0000 transparent transparent;
border-style: solid;
border-width: 0.1em 0.25em 0.1em 0.25em;
left: 0em;
bottom: -0.199375em;
}
.ribbon-top:before {
position: absolute;
height: 0;
width: 0;
content: "";
border-color: transparent #4d0000 #4d0000 transparent;
border-style: solid;
border-width: 0.1em 0.25em 0.1em 0.25em;
left: 0em;
top: -0.199375em;
}
.ribbon:after {
position: absolute;
width: 20px;
left:100%;
top: 0;
height:100%;
content: "";
background: #9c0000;
-webkit-clip-path: polygon(0% 0%, 100% 0, 0 50%, 100% 100%, 0% 100%);
clip-path: polygon(0% 0%, 100% 0, 0 50%, 100% 100%, 0% 100%);
}<div class="wrapper">
<div class="ribbon ribbon-bot">Ribbon</div>
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut non mi libero. Nam
ultrices malesuada nulla, eu faucibus eros. Nulla non est odio. Maecenas
vulputate nec sem vitae viverra. In vitae dapibus purus. Morbi mattis mi nulla,
sed iaculis justo mollis et. Integer porttitor augue nisl, ac auctor nisl
posuere vitae. Praesent at ligula fermentum, maximus mi ac, vehicula mi. Nam
ligula mi, suscipit id dictum nec, varius sagittis nisl. Lorem ipsum dolor sit
amet, consectetur adipiscing elit. Suspendisse consequat ipsum a nibh imperdiet
interdum.</p>
<div class="ribbon ribbon-top">A Moderately Long Heading Goes Here A Moderately Long Heading Goes Here</div>
<p>Donec venenatis ante tellus, venenatis consectetur arcu sagittis at. Phasellus
eu neque a dolor porta rutrum et ac lorem. Nulla ornare nisl quis est lacinia
vehicula. Sed elementum ante elit, interdum porta elit tristique ac. Praesent
felis dolor, luctus elementum nisi non, vehicula aliquet mauris. Vestibulum
fermentum erat nibh, in facilisis lorem bibendum sed. Phasellus condimentum
pharetra quam, et placerat massa auctor nec. Mauris fringilla hendrerit lectus,
nec congue elit semper tempus. Pellentesque convallis interdum ligula, et
faucibus nulla vulputate eget. Donec mattis orci at leo fringilla mollis.</p>
</div>