Fix: take the mobile safe area from CSS, not a one-time read - #66

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@11d5960a326750d5838078e36cf38b85af677262, github/codeql-action/analyze@c4dd10e44af883a891fe31ced449bcb4a6728b9b, github/codeql-action/init@c4dd10e44af883a891fe31ced449bcb4a6728b9b. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/