Add Astra child theme for Hop On Hop Off header & footer

- disables Astra header/footer via astra_header/astra_footer hooks and renders
  custom design markup (logo, nav dropdown, footer columns, socials, support)
- chrome.css scoped to .hoho (generated from the design source); chrome.js for
  burger/submenu/sticky/back-to-top; bundled icon sprite (reuses plugin's)
- parameterize scope-css.js scope via VC_SCOPE env

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J4hNL1PSHxXbu94SCenpKj

astra-child-hoponhopoff/assets/chrome.js

@@ -0,0 +1,74 @@
+/* Hop On Hop Off — header/footer interactions (child theme).
+   Ported from the mockup's main.js: burger menu, Tours submenu, sticky header
+   over a hero (solid otherwise), and the footer "back to top" button. */
+(function () {
+  "use strict";
+
+  var header = document.getElementById("siteHeader");
+  var nav = document.getElementById("primaryNav");
+  var burger = document.getElementById("burger");
+  var navToggle = nav && nav.querySelector(".nav__toggle");
+  var mqDesktop = window.matchMedia("(min-width: 60.0625rem)");
+
+  /* ---------- mobile menu ---------- */
+  function closeMenu() {
+    if (!nav || !burger) return;
+    nav.classList.remove("is-open");
+    burger.setAttribute("aria-expanded", "false");
+  }
+
+  if (burger && nav) {
+    burger.addEventListener("click", function () {
+      var open = nav.classList.toggle("is-open");
+      burger.setAttribute("aria-expanded", String(open));
+    });
+    document.addEventListener("click", function (e) {
+      if (mqDesktop.matches) return;
+      if (!nav.contains(e.target) && !burger.contains(e.target)) closeMenu();
+    });
+    nav.addEventListener("click", function (e) {
+      if (!mqDesktop.matches && e.target.closest("a")) closeMenu();
+    });
+  }
+
+  document.addEventListener("keydown", function (e) {
+    if (e.key !== "Escape") return;
+    closeMenu();
+    if (navToggle) navToggle.setAttribute("aria-expanded", "false");
+  });
+  mqDesktop.addEventListener("change", function (e) { if (e.matches) closeMenu(); });
+
+  /* ---------- Tours submenu ---------- */
+  if (navToggle) {
+    navToggle.addEventListener("click", function () {
+      var open = navToggle.getAttribute("aria-expanded") === "true";
+      navToggle.setAttribute("aria-expanded", String(!open));
+    });
+  }
+
+  /* ---------- header: sticky over a hero, solid elsewhere ---------- */
+  var hero = document.querySelector(".hero, .hero-tour, .hero--archive");
+  if (header) {
+    if (hero && "IntersectionObserver" in window) {
+      var sentinel = document.createElement("div");
+      sentinel.setAttribute("aria-hidden", "true");
+      sentinel.style.cssText = "position:absolute;top:0;left:0;width:1px;height:60vh;pointer-events:none";
+      hero.appendChild(sentinel);
+      new IntersectionObserver(function (entries) {
+        header.classList.toggle("is-stuck", !entries[0].isIntersecting);
+      }, { threshold: 0 }).observe(sentinel);
+    } else {
+      /* No hero to overlay — show a readable solid header from the start. */
+      header.classList.add("is-solid");
+    }
+  }
+
+  /* ---------- footer: back to top ---------- */
+  var toTop = document.querySelector(".ring-badge--top");
+  if (toTop) {
+    toTop.addEventListener("click", function (e) {
+      e.preventDefault();
+      window.scrollTo({ top: 0, behavior: "smooth" });
+    });
+  }
+})();