Timeline with Tracing Beam

Create a vertical timeline section with a tracing beam effect. A vertical line runs down the center; a glowing segment of the line fills from top to bottom based on scroll position. Timeline items sit on alternating sides with a small dot where they connect to the line. Use a dark background, white headlines, and muted descriptions. Use CSS height interpolation tied to scroll or a simple JS scroll listener. Use Tailwind CSS. No images.

创建一个带追踪光束效果的垂直时间线区域。一条竖线沿中心向下延伸；其中一段发光线条根据滚动位置从上到下填充。时间线项目交替分布在两侧，连接处有一个小圆点。使用深色背景、白色标题和柔和描述。使用与滚动绑定的 CSS 高度插值或简单 JS 滚动监听。使用 Tailwind CSS。无图片。