.line{width: 100%; ???height: 2px; ???background: linear-gradient( ???????????to right, ???????????rgba(0, 0, 0, 0) 0%, ???????????rgba(0, 0, 0, 0) 10%, ???????????rgba(255, 255, 255, 0.3) 20%, ???????????rgba(255, 255, 255, 0.4) 30%, ???????????rgba(255, 255, 255, 0.5) 40%, ???????????rgba(255, 255, 255, 0.8) 50%, ???????????rgba(255, 255, 255, 0.5) 60%, ???????????rgba(255, 255, 255, 0.4) 70%, ???????????rgba(255, 255, 255, 0.3) 80%, ???????????rgba(0, 0, 0, 0) 90%, ???????????rgba(0, 0, 0, 0) 100%)}css实现线条样式（中间高亮，两边透明）
原文地址：https://www.cnblogs.com/ouchen0312/p/9796838.html