perf: improve header performance by hiding when not in view (Intersection Observer API)

描述

贡献者指南

技术栈

typescriptjavascripthtmlcss

领域

frontendperformance

议题类型

performance

难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。

3

预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。

1-3 hours

活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。

stale

清晰度议题是否清楚说明期望改动、验收标准和下一步。

clear

前置要求

Intersection Observer APITypeScriptCSS

新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。

70

研究方向

This task involves implementing the Intersection Observer API to hide the header when it is not in the viewport. Start by locating the header component (likely in src/components/Header.tsx or similar). Add an effect that creates an IntersectionObserver to observe the header element. When the intersection ratio is 0, add a CSS class to hide the header (e.g., display: none). Ensure the header reappears when it becomes visible again. Test the behavior on scroll. Consider performance implications and ensure no layout shift.