diff --git a/implementations/Crafter.Build-Clang.cpp b/implementations/Crafter.Build-Clang.cpp
index 12b0534..775096e 100644
--- a/implementations/Crafter.Build-Clang.cpp
+++ b/implementations/Crafter.Build-Clang.cpp
@@ -1098,24 +1098,39 @@ void Crafter::EnableWasiBrowserRuntime(Configuration& cfg) {
     // Walk the dep graph again for non-JS assets — these get pre-loaded by
     // runtime.js into an in-memory VFS so the wasm's std::ifstream et al.
     // can actually read them (the wasi-runtime in this repo otherwise
-    // stubs every fd syscall to zero). The manifest lists basenames only;
-    // each file lives next to the .wasm in the bin dir. wasi-runtime
-    // reduces every path_open path to its basename, so subdir layouts
-    // collapse — that's fine for our flat-bin convention.
-    auto compressedBasename = [](const fs::path& src) -> std::optional<std::string> {
+    // stubs every fd syscall to zero).
+    //
+    // The manifest lists *relative paths* (e.g. "assets/Inter.ttf") so
+    // runtime.js's fetch() resolves against the bin-dir layout the asset
+    // copy step actually emits. The VFS is keyed by basename — path_open
+    // strips to basename on lookup, so subdir layouts collapse on the
+    // wasm side. Basename collisions across subdirs aren't supported on
+    // the wasi runtime today; if two assets share a basename, the last
+    // one preloaded wins. Avoid collisions in the source tree.
+    auto compressedExt = [](const fs::path& src) -> std::optional<std::string> {
         std::string ext = src.extension().string();
         for (char& c : ext) c = static_cast<char>(std::tolower(static_cast<unsigned char>(c)));
-        fs::path out = src.filename();
         if (ext == ".png" || ext == ".tga" || ext == ".jpg" || ext == ".jpeg" || ext == ".bmp") {
-            out.replace_extension(".ctex");
-        } else if (ext == ".obj") {
-            out.replace_extension(".cmesh");
-        } else {
-            return std::nullopt;
+            return std::string(".ctex");
         }
-        return out.string();
+        if (ext == ".obj") return std::string(".cmesh");
+        return std::nullopt;
+    };
+    auto compressedRel = [&](const fs::path& rel) -> fs::path {
+        if (auto ext = compressedExt(rel)) {
+            fs::path out = rel;
+            out.replace_extension(*ext);
+            return out;
+        }
+        return rel;
     };
     std::vector<std::string> assetFiles;
+    auto pushUnique = [&](std::string name) {
+        if (name.empty()) return;
+        if (std::find(assetFiles.begin(), assetFiles.end(), name) == assetFiles.end()) {
+            assetFiles.push_back(std::move(name));
+        }
+    };
     seen.clear();
     std::function<void(Configuration*)> walkAssets = [&](Configuration* c) {
         if (!c || !seen.insert(c).second) return;
@@ -1123,35 +1138,25 @@ void Crafter::EnableWasiBrowserRuntime(Configuration& cfg) {
             std::string ext = f.extension().string();
             if (ext == ".js" || ext == ".html") continue;
             if (f.filename() == "runtime.js") continue;
-            std::string name = f.filename().string();
-            if (name.empty()) continue;
-            if (std::find(assetFiles.begin(), assetFiles.end(), name) == assetFiles.end()) {
-                assetFiles.push_back(std::move(name));
-            }
+            // cfg.files lands flat next to the .wasm by `name = filename()`.
+            pushUnique(f.filename().string());
         }
-        // cfg.assets — emit the *compressed* output basename. Directory
-        // entries get the same compressed-basename treatment per file;
-        // unrecognized extensions are treated as passthrough (kept under
-        // their original name, matching the build-side passthrough copy).
+        // cfg.assets — mirror the bin-dir layout the build emits: a
+        // directory entry becomes <topName>/<rel inside dir>, single
+        // files land flat at the bin root. .png/.obj are compressed in
+        // place; everything else passes through under its original name.
         for (const fs::path& a : c->assets) {
             if (fs::is_directory(a)) {
+                const fs::path topName = a.filename();
                 std::error_code ec;
                 for (const auto& entry : fs::recursive_directory_iterator(a, ec)) {
                     if (ec) break;
                     if (!entry.is_regular_file()) continue;
-                    std::string name = compressedBasename(entry.path())
-                        .value_or(entry.path().filename().string());
-                    if (name.empty()) continue;
-                    if (std::find(assetFiles.begin(), assetFiles.end(), name) == assetFiles.end()) {
-                        assetFiles.push_back(std::move(name));
-                    }
+                    fs::path rel = fs::relative(entry.path(), a);
+                    pushUnique((topName / compressedRel(rel)).generic_string());
                 }
             } else {
-                std::optional<std::string> name = compressedBasename(a);
-                if (!name) continue;
-                if (std::find(assetFiles.begin(), assetFiles.end(), *name) == assetFiles.end()) {
-                    assetFiles.push_back(std::move(*name));
-                }
+                pushUnique(compressedRel(a.filename()).generic_string());
             }
         }
         for (Configuration* dep : c->dependencies) walkAssets(dep);
diff --git a/wasi-runtime/runtime.js b/wasi-runtime/runtime.js
index ceaae77..2ce232c 100644
--- a/wasi-runtime/runtime.js
+++ b/wasi-runtime/runtime.js
@@ -301,6 +301,12 @@ if (!wasmUrl) {
 // EnableWasiBrowserRuntime) into an in-memory VFS so wasi-libc's file
 // syscalls work against them. Browser builds otherwise can't open assets
 // shipped alongside the .wasm — sync XHR is too deprecated to rely on.
+//
+// Manifest entries are relative paths under the bin dir (the layout
+// `cfg.assets` produces — e.g. "assets/Inter.ttf",
+// "mods/3DForts_Base/foo.cmesh"). We fetch each at its full path but
+// key the VFS by basename so `path_open`'s basename-reduction can find
+// it regardless of the C++ side's cwd or prefix.
 const vfs = new Map();
 try {
     const manifestResp = await fetch("files.json");
@@ -308,8 +314,12 @@ try {
         const names = await manifestResp.json();
         await Promise.all(names.map(async (name) => {
             const r = await fetch(name);
-            if (r.ok) vfs.set(name, new Uint8Array(await r.arrayBuffer()));
-            else console.warn(`[wasi] failed to preload ${name}: HTTP ${r.status}`);
+            if (!r.ok) {
+                console.warn(`[wasi] failed to preload ${name}: HTTP ${r.status}`);
+                return;
+            }
+            const base = name.split(/[\\/]/).filter(Boolean).pop() || name;
+            vfs.set(base, new Uint8Array(await r.arrayBuffer()));
         }));
     }
 } catch (e) {