带框的加号（添加按钮）

鼠标悬浮时会高亮

<template><div style="padding: 20px"><div class="add"></div></div></template><style scoped>.add {display: inline-block;width: 76px; height: 76px;color: #ccc;border: 2px dashed;transition: color .25s;position: relative;overflow: hidden;}.add:hover {color: #34538b;}.add::before, .add::after {content: '';position: absolute;top: 50%;left: 50%;}.add::before {width: 20px;border-top: 4px solid;margin: -2px 0 0 -10px;}.add::after {height: 20px;border-left: 4px solid;margin: -10px 0 0 -2px;}</style>

三横（三道杠）

<template><div><div class="icon-menu"></div></div></template><style scoped>.icon-menu {width: 10px;height: 2px;border-top: 6px double;border-bottom: 2px solid;}</style>

或

<template><div><i class="icon-menu"></i></div></template><style scoped>.icon-menu {display: inline-block;width: 16px;height: 2px;padding: 4px 0;border-top: 2px solid;border-bottom: 2px solid;background-color: currentColor;background-clip: content-box;}</style>

带圈点（双层圆点）

<template><div><i class="icon-dot"></i></div></template><style scoped>.icon-dot {display: inline-block;width: 16px;height: 16px;padding: 4px;border: 4px solid;border-radius: 50%;background-color: currentColor;background-clip: content-box;}</style>