工具页 Tool 游戏/互动 Game / interactive
Flatten SF：在旧金山找最平的步行/骑车路线 Flatten SF: the flattest walking or cycling route across San Francisco
一根滑杆，在少走路和少爬坡之间挑。 One slider between shorter and flatter.
详细介绍Details
地图数据来自 Overture / OpenStreetMap，高程用 USGS 3DEP。页面署名 Drew Edwards。 drag the slider to trade distance for climbing while the panel updates distance, total climb, steepest grade, and an elevation profile, with a copy-link button. Map data from Overture / OpenStreetMap, elevation from USGS 3DEP. Credited to Drew Edwards.
适合学什么What to learn
- 工具页 Tool
在浏览器里生成 CSS/HTML 的小工具。 In-browser tools that generate CSS or HTML.
- 游戏/互动 Game / interactive
可直接玩或操作的教学游戏与 WebGL 演示。 Teaching games and WebGL demos you can play in the browser.
为什么推荐Why we recommend it 收录理由：一个滑杆把「最短 vs 最平」的取舍讲得一目了然，交互和信息面板都值得借鉴。边界：只覆盖旧金山；有评论说个别路段推荐不准；未见公开代码仓库。预览自托管。 Why listed: one slider makes the shortest-versus-flattest trade-off obvious, and both the interaction and the info panel are worth borrowing. Boundary: San Francisco only; a commenter reports some suggestions are off; no public code repo seen.
核验记录：来源、抓取与截图说明Verification log: sources, checks, and captures
主源是 HN 49971230 与公开页（早间 HTTP 200）。 HN 首页 item 49971230（2026-10-05T21:40:50Z / 约 10-06 05:40 CST，早间约 96 分）https://flattensf.com/ —— 输入起点终点，选步行或骑车，它会给出从最短到最平的一整串路线（截图里是 30 条），拖动滑杆就能在「少走路」和「少爬坡」之间换，左侧同步显示距离、累计爬升、最陡坡度和高程曲线，还能复制链接分享。 预览为无头浏览器实拍首屏裁 3:2 WebP。Primary sources are HN 49971230 and the public page (HTTP 200 this morning). Preview is self-hosted. HN front page item 49971230 (2026-10-05T21:40:50Z / about 05:40 CST on 10-06, about 96 points this morning) at https://flattensf.com/ — enter two places, pick walk or bike, and it lists every route from shortest to flattest (30 in the capture); Preview is a headless-browser capture of the first screen, cropped to 3:2 WebP.
