这是一条普通的HTML分割线

<hr class="line1">

两条实线

.line1{
  border: 0;
  border-bottom: 3px double;
}

一条虚线

.line1{
  border: 0;
  border-bottom: 1px dotted;
}

一条可控线段长度与间距的虚线

.line1{
  border: 0;
  padding-top: 1px;
  background: repeating-linear-gradient(to right, #a2a9b6 0px, #a2a9b6 4px, transparent 0px, transparent 10px);
}

两端淡出的分割线

.line1{  
  border: 0;
  padding-top: 1px;
  background: linear-gradient(to right, transparent, #d0d0d5, transparent);
}

斜纹分隔线

.line1{  
  border: 0;
  padding: 3px;
  background: repeating-linear-gradient(135deg, #a2a9b6 0px, #a2a9b6 1px, transparent 1px, transparent 6px);
}

炫丽的斜纹分隔线

.line1{
  border: 0;
  padding: 3px;
  background: linear-gradient(135deg, red, orange,green, blue, purple);
  --mask-image: repeating-linear-gradient(135deg, #000 0px, #000 1px, transparent 1px, transparent 6px);
  -webkit-mask-image: var(--mask-image);
  mask-image: var(--mask-image);
}

波浪线

.line1 {
    border: 0;
    color: #d0d0d5;
    height: .5em;
    white-space: nowrap;
    letter-spacing: 100vw;
    padding-top: .5em;
}
.line1::before {
  content: "\2000\2000";
  text-decoration: overline wavy;
}

阴影线

.line1 {
  border: 0;
  padding-top: 10px;
  color: #d0d0d5;
  border-top: 1px solid rgba(0,0,0,.1);
  box-shadow: inset 0 10px 10px -10px;
}

中心图形装饰分隔线

.line1 {
  border: 0;
  color: #d0d0d5;
  background: linear-gradient(currentColor, currentColor) no-repeat center;
  background-size: 100% 1px;
}
.line1::before {
    content: '';
    display: block;
    width: .5em; height: .5em;
    transform: rotate(45deg);
    background-color: currentColor;
    margin: 3px auto;
}

两端图形装饰分隔线

.line1 {
  border: 0;
  color: #d0d0d5;
  background: linear-gradient(currentColor, currentColor) no-repeat center;
  background-size: calc(100% - 1.5em - 6px) 1px;
  display: flex;
  justify-content: space-between;
}
.line1::before, .line1::after {
  content: '';
  display: block;
  width: .75em; height: .75em;
  transform: rotate(45deg);
  box-sizing: border-box;
  border: 1px solid;
  margin: 3px;
}

复杂装饰分隔线

.line1 {
  color: #d0d0d5;
  border: double;
  border-width: 3px 5px;
  border-color: #d0d0d5 transparent;
  height: 1px;
  overflow: visible;
  margin-left: 20px;
  margin-right: 20px;
  position: relative;
}
.line1:before,
.line1:after {
    content: '';
    position: absolute;
    width: 5px; height: 5px;
    border-width: 0 3px 3px 0;
    border-style: double;
    top: -3px;
    background: radial-gradient(2px at 1px 1px, currentColor 2px, transparent 0) no-repeat;
}
.line1:before {
    transform: rotate(-45deg);
    left: -20px;
}
.line1:after {
    transform: rotate(135deg);
    right: -20px;
}

带文字的分隔线

这里的HTML部分要增加一个data-属性用来配置文字

<hr class="line1" data-content="分隔线">

然后CSS：

.line1 {
  color: #a2a9b6;
  border: 0;
  font-size: 12px;
  padding: 1em 0;
  position: relative;
}
.line1::before {
    content: attr(data-content);
    position: absolute;
    padding: 0 1ch;
    line-height: 1px;
    border: solid #d0d0d5;
    border-width: 0 99vw;
    width: fit-content;
    /* for 不支持fit-content浏览器 */
    white-space: nowrap;
    left: 50%;
    transform: translateX(-50%);
}

学习自： https://www.zhangxinxu.com/wordpress/2021/05/css-html-hr/