<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
.tab-x {
display: flex;
flex-direction: row-reverse;
justify-content: flex-end;
padding-left: 20px;
border-bottom: 1px solid rgba(0, 0, 0, .1);
}
.tab-a {
--backgroundColor: #fff;
background-color: var(--backgroundColor);
line-height: 20px;
padding: 10px 20px;
border-radius: 16px 16px 0 0;
filter: drop-shadow(0 -1px 1px rgba(0, 0, 0, .1));
position: relative;
}
/* 创建外侧圆弧 */
.tab-a::before,
.tab-a::after {
content: '';
position: absolute;
bottom: 0;
16px;
height: 16px;
}
.tab-a::before {
background: radial-gradient(circle at 0 0, transparent, transparent 16px, var(--backgroundColor) 17px);
right: 100%;
}
.tab-a::after {
background: radial-gradient(circle at 100% 0, transparent, transparent 16px, var(--backgroundColor) 17px);
left: 100%;
}
.tab-a.active {
--backgroundColor: teal;
color: #fff;
z-index: 1;
}
</style>
</head>
<body>
<div class="tab-x">
<a href="javascript:" class="tab-a">选项卡3</a>
<a href="javascript:" class="tab-a">选项卡2</a>
<a href="javascript:" class="tab-a active">选项卡1</a>
</div>
</body>
</html>
效果图：
