Choose your own block explorer; flatten How it works

- Settings → Block explorer: pick mempool.space (default, with
  blockstream.info as a silent failover), blockstream.info only, or a
  custom Esplora/electrs REST URL (e.g. your own node). The realtime
  WebSocket only applies to mempool.space; other explorers fall back to
  polling. Switching rebuilds the API and rescans. Replaces the old
  undocumented explorer-proxy hack.
- How it works: merge the "For the technically curious" disclosure into
  the main body so it's all visible under "The basics", and dedupe the
  overlapping no-server/offline sentences. Mentions the new explorer
  setting.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

1 files changed, 0 insertions, 5 deletions

diff --git a/src/style.css b/src/style.css
index 136473a..a74c7e5 100644
--- a/src/style.css
+++ b/src/style.css
@@ -248,11 +248,6 @@ hr.divider { margin: 16px 0; }
 .linklike:hover { text-decoration: underline; background: none; }
 
 /* ---- how it works ---- */
-.hiw-tech {border-top: 1px solid var(--line); padding-top: 14px; }
-.hiw-tech > summary { font-weight: 650; cursor: pointer; list-style: none; color: var(--accent-ink); display: flex; align-items: center; gap: 7px; }
-.hiw-tech > summary::-webkit-details-marker { display: none; }
-.hiw-tech > summary::before { content: '▸'; font-size: 12px; transition: transform .15s; }
-.hiw-tech[open] > summary::before { transform: rotate(90deg); }
 
 @media (max-width: 420px) {
   .words { grid-template-columns: repeat(2, 1fr); }