diff --git a/.gitignore b/.gitignore
index 02c20f5..4387ac0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,9 +2,8 @@
 
 /target
 /build
+/.deps
 
 /.claude/settings.local.json
 /.claude.local/
 
-/playground/node_modules/
-/playground/src/placeholder.wasm
diff --git a/CLAUDE.md b/CLAUDE.md
index f228875..1612f7c 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -5,37 +5,48 @@
 All dependency versions are declared in one place:
 
 - **Rust crates**: `Cargo.toml` `[dependencies]`
-- **Asset dependencies** (e.g. playground artifact): `Cargo.toml` `[package.metadata.assets.<name>]`
+- **Asset dependencies** (e.g. playground, brand): `Cargo.toml` `[package.metadata.assets.<name>]`
 
 ### Updating dependencies
 
 Run `cargo run -- update-deps` to update all dependencies:
 
 1. Runs `cargo update` (Rust crates)
-2. Downloads asset dependencies from GitHub releases into `build/assets/`
+2. Downloads asset dependencies from GitHub releases into `.deps/`
 
 ### Build vs fetch
 
-- `cargo run` (or `cargo run -- build`) builds with what is already in `build/assets/`. It will error if a referenced asset is missing.
+- `cargo run` (or `cargo run -- build`) builds with what is already in `.deps/`. It will error if a referenced asset is missing.
 - `cargo run -- update-deps` fetches/updates dependencies. It does not build.
 - A clean build should never fetch dependencies.
 
-## Build output
+## Project layout
 
 ```
+.deps/              # downloaded dependencies — NOT wiped by build, gitignored
+  playground/       # playground artifact (JS/WASM/CSS)
+  brand/            # brand assets (logo SVGs, favicon PNGs, social image)
 build/
-  assets/     # downloaded dependencies — NOT wiped by build
-  site/       # generated output — wiped on each build
+  site/             # generated output — wiped on each build
+static/             # static files copied verbatim to build/site/
+                    # (brand assets here are fallbacks, overridden by .deps/brand/)
 ```
 
-`build/` is gitignored. The dev server (`cargo run -- serve`) serves from `build/site/`.
+The dev server (`cargo run -- serve`) serves from `build/site/`.
+
+## Brand assets
+
+Brand assets (logo, favicons, social image) come from the `brand` dependency.
+The build copies them from `.deps/brand/assets/` into `build/site/`, overriding
+any fallback files in `static/`. Once the brand release is live, the fallback
+copies in `static/` can be removed.
 
 ## Fragment injection
 
-Content pages can inject HTML fragments from `build/assets/` using frontmatter:
+Content pages can inject HTML fragments from `.deps/` using frontmatter:
 
 ```yaml
-fragment: playground/fragment.html   # path relative to build/assets/
+fragment: playground/fragment.html   # path relative to .deps/
 asset_dir: playground                # copies runtime files to build/site/<path>
 ```
 
diff --git a/Cargo.lock b/Cargo.lock
index 1c4e439..c6e6b25 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -11,6 +11,12 @@ dependencies = [
  "gimli 0.33.0",
 ]
 
+[[package]]
+name = "adler2"
+version = "2.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
+
 [[package]]
 name = "aho-corasick"
 version = "1.1.4"
@@ -119,6 +125,18 @@ dependencies = [
  "allocator-api2",
 ]
 
+[[package]]
+name = "bytemuck"
+version = "1.25.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c8efb64bd706a16a1bdde310ae86b351e4d21550d98d056f22f8a7f7a2183fec"
+
+[[package]]
+name = "byteorder-lite"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f1fe948ff07f4bd06c30984e69f5b4899c516a3ef74f34df92a2df2ab535495"
+
 [[package]]
 name = "cc"
 version = "1.2.57"
@@ -507,6 +525,15 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"
 
+[[package]]
+name = "fdeflate"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e6853b52649d4ac5c0bd02320cddc5ba956bdb407c4b75a2c6b75bf51500f8c"
+dependencies = [
+ "simd-adler32",
+]
+
 [[package]]
 name = "find-msvc-tools"
 version = "0.1.9"
@@ -515,8 +542,8 @@ checksum = "5baebc0774151f905a1a2cc41989300b1e6fbb29aff0ceffa1064fdd3088d582"
 
 [[package]]
 name = "fink"
-version = "0.1.0"
-source = "git+https://github.com/fink-lang/fink.git?branch=main#c311109ecd6f92540a3094d6215b6fa4fe97d9b7"
+version = "0.0.0"
+source = "git+https://github.com/fink-lang/fink.git?tag=v0.1.0#1a61a6b21aa0ad51c2f03e4062df64f774a17ae1"
 dependencies = [
  "dap",
  "tokio",
@@ -533,6 +560,8 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "fink",
+ "flate2",
+ "image",
  "pulldown-cmark",
  "tera",
  "tiny_http",
@@ -545,6 +574,16 @@ version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0ce7134b9999ecaf8bcd65542e436736ef32ddca1b3e06094cb6ec5755203b80"
 
+[[package]]
+name = "flate2"
+version = "1.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "843fba2746e448b37e26a819579957415c8cef339bf08564fe8b7ddbd959573c"
+dependencies = [
+ "crc32fast",
+ "miniz_oxide",
+]
+
 [[package]]
 name = "fnv"
 version = "1.0.7"
@@ -844,6 +883,19 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "image"
+version = "0.25.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85ab80394333c02fe689eaf900ab500fbd0c2213da414687ebf995a65d5a6104"
+dependencies = [
+ "bytemuck",
+ "byteorder-lite",
+ "moxcms",
+ "num-traits",
+ "png",
+]
+
 [[package]]
 name = "indexmap"
 version = "2.13.0"
@@ -980,6 +1032,26 @@ dependencies = [
  "rustix",
 ]
 
+[[package]]
+name = "miniz_oxide"
+version = "0.8.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1fa76a2c86f704bdb222d66965fb3d63269ce38518b83cb0575fca855ebb6316"
+dependencies = [
+ "adler2",
+ "simd-adler32",
+]
+
+[[package]]
+name = "moxcms"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bb85c154ba489f01b25c0d36ae69a87e4a1c73a72631fc6c0eb6dde34a73e44b"
+dependencies = [
+ "num-traits",
+ "pxfm",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.19"
@@ -1125,6 +1197,19 @@ version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7edddbd0b52d732b21ad9a5fab5c704c14cd949e5e9a1ec5929a24fded1b904c"
 
+[[package]]
+name = "png"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "60769b8b31b2a9f263dae2776c37b1b28ae246943cf719eb6946a1db05128a61"
+dependencies = [
+ "bitflags",
+ "crc32fast",
+ "fdeflate",
+ "flate2",
+ "miniz_oxide",
+]
+
 [[package]]
 name = "postcard"
 version = "1.1.3"
@@ -1207,6 +1292,12 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "pxfm"
+version = "0.1.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5a041e753da8b807c9255f28de81879c78c876392ff2469cde94799b2896b9d"
+
 [[package]]
 name = "quote"
 version = "1.0.45"
@@ -1479,6 +1570,12 @@ version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
 
+[[package]]
+name = "simd-adler32"
+version = "0.3.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e320a6c5ad31d271ad523dcf3ad13e2767ad8b1cb8f047f75a8aeaf8da139da2"
+
 [[package]]
 name = "siphasher"
 version = "1.0.2"
diff --git a/Cargo.toml b/Cargo.toml
index 0a91568..3d9554f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,12 +6,19 @@ edition = "2024"
 [package.metadata.assets.playground]
 url = "https://github.com/fink-lang/playground/releases/download/{version}/playground.tar.gz"
 version = "v1.9.0"
-dest = "build/assets/playground"
+dest = ".deps/playground"
+
+[package.metadata.assets.brand]
+url = "https://github.com/fink-lang/brand/releases/download/{version}/brand-assets.tar.gz"
+version = "v1.0.0"
+dest = ".deps/brand"
 
 [dependencies]
-fink = { git = "https://github.com/fink-lang/fink.git", branch = "main" }
+fink = { git = "https://github.com/fink-lang/fink.git", tag = "v0.1.0" }
 pulldown-cmark = "0.13"
 tera = "1"
 walkdir = "2"
 anyhow = "1"
 tiny_http = "0.12"
+flate2 = "1"
+image = { version = "0.25", default-features = false, features = ["png"] }
diff --git a/src/main.rs b/src/main.rs
index 1990bbd..eea0339 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -5,17 +5,18 @@
 // build/site/index.html for the root page). Static files in static/ are copied
 // verbatim.
 //
-// Downloaded dependencies (e.g. playground artifact) live in build/assets/.
-// Only build/site/ is wiped on each build; build/assets/ is preserved.
+// Downloaded dependencies (e.g. playground, brand) live in .deps/.
+// Only build/site/ is wiped on each build; .deps/ is preserved.
 //
 // Content file frontmatter (YAML between --- markers) supports:
 //   title: string       — page <title> and heading
 //   template: string    — Tera template name without extension (default: "page")
-//   fragment: path      — HTML fragment to inject (relative to ASSETS_DIR)
-//   asset_dir: path     — copies runtime files from ASSETS_DIR/<path> to output
+//   fragment: path      — HTML fragment to inject (relative to .deps/)
+//   asset_dir: path     — copies runtime files from .deps/<path> to output
 
 mod highlight;
 mod markdown;
+mod playground;
 mod serve;
 mod svg;
 
@@ -31,7 +32,7 @@ const CONTENT_DIR: &str = "content";
 const TEMPLATE_DIR: &str = "templates";
 const STATIC_DIR: &str = "static";
 const SITE_DIR: &str = "build/site";
-const ASSETS_DIR: &str = "build/assets";
+const DEPS_DIR: &str = ".deps";
 const DEFAULT_PORT: u16 = 8080;
 
 fn main() -> Result<()> {
@@ -62,10 +63,14 @@ fn main() -> Result<()> {
       update_deps()?;
       return Ok(());
     }
+    Some("check-deps") => {
+      check_deps()?;
+      return Ok(());
+    }
     Some("build") | None => {}
     Some(other) => {
       eprintln!("Unknown command: {other}");
-      eprintln!("Usage: fink-site [build | serve [port] | stop | update-deps | svg <file>]");
+      eprintln!("Usage: fink-site [build | serve [port] | stop | update-deps | check-deps | svg <file>]");
       std::process::exit(1);
     }
   }
@@ -96,6 +101,9 @@ fn build() -> Result<()> {
   // Copy static assets
   copy_static()?;
 
+  // Copy brand assets from .deps/brand/ into build/site/
+  copy_brand()?;
+
   println!("Build complete → {}/", SITE_DIR);
   Ok(())
 }
@@ -167,7 +175,7 @@ fn render_page(md_path: &Path, tera: &Tera) -> Result<()> {
 
   // Load HTML fragment from assets if requested
   let fragment = if let Some(frag_path) = &fragment_path {
-    let full = Path::new(ASSETS_DIR).join(frag_path);
+    let full = Path::new(DEPS_DIR).join(frag_path);
     let html = fs::read_to_string(&full)
       .with_context(|| format!("failed to read fragment {}", full.display()))?;
     Some(html)
@@ -177,7 +185,7 @@ fn render_page(md_path: &Path, tera: &Tera) -> Result<()> {
 
   // Copy runtime asset directory if requested (e.g. JS/WASM/CSS files)
   if let Some(dir) = &asset_dir {
-    let src = Path::new(ASSETS_DIR).join(dir);
+    let src = Path::new(DEPS_DIR).join(dir);
     let dest_dir = Path::new(SITE_DIR).join(dir);
     if src.is_dir() {
       copy_dir(&src, &dest_dir)
@@ -264,29 +272,72 @@ fn copy_dir(src: &Path, dest: &Path) -> Result<()> {
   Ok(())
 }
 
-// ---- dependency management -------------------------------------------------
+// ---- brand assets ----------------------------------------------------------
 
-/// Run `cargo update` and download asset dependencies listed in Cargo.toml
-/// under [package.metadata.assets.<name>].
-fn update_deps() -> Result<()> {
-  // 1. Run cargo update for crate dependencies
-  println!("Running cargo update…");
-  let status = std::process::Command::new("cargo")
-    .arg("update")
-    .status()
-    .context("failed to run cargo update")?;
-  if !status.success() {
-    anyhow::bail!("cargo update failed");
+const BRAND_DIR: &str = ".deps/brand";
+
+/// Copy brand assets from .deps/brand/ into the site output directory.
+/// SVGs are copied directly; PNGs are downscaled to the sizes needed for
+/// favicons, apple-touch-icon, and social image.
+fn copy_brand() -> Result<()> {
+  let brand = Path::new(BRAND_DIR);
+  if !brand.exists() {
+    // Brand dep not fetched — static/ fallbacks will be used
+    return Ok(());
   }
 
-  // 2. Download asset dependencies from Cargo.toml metadata
+  let site = Path::new(SITE_DIR);
+
+  // Logo SVG (nav, hero, SVG favicon)
+  let logo_src = brand.join("assets/fink-rect-no-bg.svg");
+  anyhow::ensure!(logo_src.exists(), "required brand asset missing: {}", logo_src.display());
+  fs::copy(&logo_src, site.join("logo.svg"))?;
+
+  // Favicons downscaled from the no-bg PNG (transparent)
+  let icon_src = brand.join("assets/fink-rect-no-bg.png");
+  anyhow::ensure!(icon_src.exists(), "required brand asset missing: {}", icon_src.display());
+  downscale_png(&icon_src, &site.join("favicon-32.png"), 32)?;
+  downscale_png(&icon_src, &site.join("favicon-192.png"), 192)?;
+
+  // Apple touch icon from rounded variant (iOS masks transparent icons to black)
+  let apple_src = brand.join("assets/fink-rounded.png");
+  anyhow::ensure!(apple_src.exists(), "required brand asset missing: {}", apple_src.display());
+  downscale_png(&apple_src, &site.join("apple-touch-icon.png"), 180)?;
+
+  // Social / og:image from wordmark (already 1200×630)
+  let social_src = brand.join("assets/fink-wordmark.png");
+  anyhow::ensure!(social_src.exists(), "required brand asset missing: {}", social_src.display());
+  fs::copy(&social_src, site.join("social.png"))?;
+
+  Ok(())
+}
+
+/// Downscale a PNG to a square of the given size using Lanczos3 filtering.
+fn downscale_png(src: &Path, dest: &Path, size: u32) -> Result<()> {
+  let img = image::open(src)
+    .with_context(|| format!("failed to open {}", src.display()))?;
+  let resized = img.resize_exact(size, size, image::imageops::FilterType::Lanczos3);
+  resized.save(dest)
+    .with_context(|| format!("failed to write {}", dest.display()))?;
+  Ok(())
+}
+
+// ---- dependency management -------------------------------------------------
+
+struct AssetDep {
+  name: String,
+  url: String,
+  version: String,
+  dest: String,
+}
+
+/// Parse [package.metadata.assets.*] entries from Cargo.toml.
+fn parse_asset_deps() -> Result<Vec<AssetDep>> {
   let toml_str = fs::read_to_string("Cargo.toml")
     .context("failed to read Cargo.toml")?;
 
-  // Parse [package.metadata.assets.*] entries.
-  // Each has: url (with {version} placeholder), version, dest
   let mut in_asset: Option<String> = None;
-  let mut assets: Vec<(String, String, String, String)> = vec![]; // (name, url, version, dest)
+  let mut assets: Vec<AssetDep> = vec![];
   let mut url = String::new();
   let mut version = String::new();
   let mut dest = String::new();
@@ -294,10 +345,9 @@ fn update_deps() -> Result<()> {
   for line in toml_str.lines() {
     let trimmed = line.trim();
     if let Some(rest) = trimmed.strip_prefix("[package.metadata.assets.") {
-      // Save previous asset if any
       if let Some(name) = in_asset.take() {
         if !url.is_empty() && !version.is_empty() && !dest.is_empty() {
-          assets.push((name, url.clone(), version.clone(), dest.clone()));
+          assets.push(AssetDep { name, url: url.clone(), version: version.clone(), dest: dest.clone() });
         }
       }
       in_asset = Some(rest.trim_end_matches(']').to_string());
@@ -319,21 +369,47 @@ fn update_deps() -> Result<()> {
   }
   if let Some(name) = in_asset {
     if !url.is_empty() && !version.is_empty() && !dest.is_empty() {
-      assets.push((name, url, version, dest));
+      assets.push(AssetDep { name, url, version, dest });
     }
   }
 
-  for (name, url_template, ver, dest_dir) in &assets {
-    let resolved_url = url_template.replace("{version}", ver);
-    println!("Fetching {name} {ver}…");
+  Ok(assets)
+}
+
+/// Extract "owner/repo" from a GitHub release URL.
+fn github_repo_from_url(url: &str) -> Option<String> {
+  // https://github.com/{owner}/{repo}/releases/download/...
+  let rest = url.strip_prefix("https://github.com/")?;
+  let parts: Vec<&str> = rest.splitn(4, '/').collect();
+  if parts.len() >= 3 && parts[2] == "releases" {
+    Some(format!("{}/{}", parts[0], parts[1]))
+  } else {
+    None
+  }
+}
+
+/// Run `cargo update` and download asset dependencies.
+fn update_deps() -> Result<()> {
+  println!("Running cargo update…");
+  let status = std::process::Command::new("cargo")
+    .arg("update")
+    .status()
+    .context("failed to run cargo update")?;
+  if !status.success() {
+    anyhow::bail!("cargo update failed");
+  }
+
+  let assets = parse_asset_deps()?;
 
-    // Clean and recreate dest
-    if Path::new(dest_dir).exists() {
-      fs::remove_dir_all(dest_dir)?;
+  for dep in &assets {
+    let resolved_url = dep.url.replace("{version}", &dep.version);
+    println!("Fetching {} {}…", dep.name, dep.version);
+
+    if Path::new(&dep.dest).exists() {
+      fs::remove_dir_all(&dep.dest)?;
     }
-    fs::create_dir_all(dest_dir)?;
+    fs::create_dir_all(&dep.dest)?;
 
-    // Download and extract tarball
     let status = std::process::Command::new("curl")
       .args(["-sL", &resolved_url])
       .stdout(std::process::Stdio::piped())
@@ -341,15 +417,15 @@ fn update_deps() -> Result<()> {
       .context("failed to run curl")?;
 
     let tar_status = std::process::Command::new("tar")
-      .args(["-xzf", "-", "-C", dest_dir])
+      .args(["-xzf", "-", "-C", &dep.dest])
       .stdin(status.stdout.unwrap())
       .status()
       .context("failed to run tar")?;
 
     if !tar_status.success() {
-      anyhow::bail!("failed to download/extract {name} from {resolved_url}");
+      anyhow::bail!("failed to download/extract {} from {resolved_url}", dep.name);
     }
-    println!("  → {dest_dir}/");
+    println!("  → {}/", dep.dest);
   }
 
   if assets.is_empty() {
@@ -358,3 +434,130 @@ fn update_deps() -> Result<()> {
 
   Ok(())
 }
+
+/// Query the latest release tag for a GitHub repo. Returns None on failure.
+fn github_latest_tag(repo: &str) -> Option<String> {
+  let output = std::process::Command::new("curl")
+    .args(["-sf", &format!("https://api.github.com/repos/{repo}/releases/latest")])
+    .output()
+    .ok()?;
+
+  if !output.status.success() { return None; }
+
+  // Extract tag_name from JSON (simple string search to avoid a JSON dep)
+  // Looks for: "tag_name": "v1.2.3"
+  let body = String::from_utf8_lossy(&output.stdout);
+  body.find("\"tag_name\"").and_then(|i| {
+    let after_key = &body[i + "\"tag_name\"".len()..];
+    let val_start = after_key.find('"')? + 1;
+    let val_end = after_key[val_start..].find('"')?;
+    Some(after_key[val_start..val_start + val_end].to_string())
+  })
+}
+
+/// Parse git dependencies with tag pins from Cargo.toml.
+/// Returns (name, repo "owner/repo", pinned tag).
+fn parse_git_deps() -> Result<Vec<(String, String, String)>> {
+  let toml_str = fs::read_to_string("Cargo.toml")
+    .context("failed to read Cargo.toml")?;
+
+  let mut deps = vec![];
+  for line in toml_str.lines() {
+    let trimmed = line.trim();
+    // Match: name = { git = "https://github.com/owner/repo.git", tag = "v1.0.0" }
+    if let Some((key, value)) = trimmed.split_once('=') {
+      let name = key.trim();
+      let val = value.trim();
+      if val.contains("git =") && val.contains("tag =") {
+        let git_url = extract_field(val, "git");
+        let tag = extract_field(val, "tag");
+        if let (Some(url), Some(tag)) = (git_url, tag) {
+          if let Some(repo) = github_repo_from_git_url(&url) {
+            deps.push((name.to_string(), repo, tag));
+          }
+        }
+      }
+    }
+  }
+  Ok(deps)
+}
+
+/// Extract a quoted field value from an inline TOML table, e.g. `git` from `{ git = "..." }`.
+fn extract_field(s: &str, field: &str) -> Option<String> {
+  let pattern = format!("{field} = \"");
+  let start = s.find(&pattern)? + pattern.len();
+  let end = s[start..].find('"')?;
+  Some(s[start..start + end].to_string())
+}
+
+/// Extract "owner/repo" from a GitHub .git URL.
+fn github_repo_from_git_url(url: &str) -> Option<String> {
+  // https://github.com/owner/repo.git
+  let rest = url.strip_prefix("https://github.com/")?;
+  let rest = rest.strip_suffix(".git").unwrap_or(rest);
+  let parts: Vec<&str> = rest.splitn(3, '/').collect();
+  if parts.len() >= 2 {
+    Some(format!("{}/{}", parts[0], parts[1]))
+  } else {
+    None
+  }
+}
+
+/// Check for newer releases of all dependencies via the GitHub API.
+fn check_deps() -> Result<()> {
+  let assets = parse_asset_deps()?;
+  let git_deps = parse_git_deps()?;
+
+  if assets.is_empty() && git_deps.is_empty() {
+    println!("No dependencies found in Cargo.toml");
+    return Ok(());
+  }
+
+  let mut all_current = true;
+
+  // Check git dependencies (crates pinned to tags)
+  for (name, repo, tag) in &git_deps {
+    match github_latest_tag(repo) {
+      Some(ref latest) if latest == tag => {
+        println!("  {name} {tag} ✓");
+      }
+      Some(ref latest) => {
+        println!("  {name} {tag} → {latest} available");
+        all_current = false;
+      }
+      None => {
+        println!("  {name} {tag} (failed to query GitHub API)");
+      }
+    }
+  }
+
+  // Check asset dependencies
+  for dep in &assets {
+    let repo = match github_repo_from_url(&dep.url) {
+      Some(r) => r,
+      None => {
+        println!("  {} {} (skipped — not a GitHub release URL)", dep.name, dep.version);
+        continue;
+      }
+    };
+
+    match github_latest_tag(&repo) {
+      Some(ref tag) if tag == &dep.version => {
+        println!("  {} {} ✓", dep.name, dep.version);
+      }
+      Some(ref tag) => {
+        println!("  {} {} → {tag} available", dep.name, dep.version);
+        all_current = false;
+      }
+      None => {
+        println!("  {} {} (failed to query GitHub API)", dep.name, dep.version);
+      }
+    }
+  }
+
+  if all_current {
+    println!("All dependencies are up to date.");
+  }
+
+  Ok(())
+}
diff --git a/src/markdown.rs b/src/markdown.rs
index 7c71f48..6d6c6c2 100644
--- a/src/markdown.rs
+++ b/src/markdown.rs
@@ -11,6 +11,7 @@
 use pulldown_cmark::{CodeBlockKind, Event, HeadingLevel, Options, Parser, Tag, TagEnd, html};
 
 use crate::highlight;
+use crate::playground;
 
 /// A single TOC entry extracted from a ## heading.
 pub struct TocEntry {
@@ -97,9 +98,20 @@ pub fn render(md: &str) -> String {
         in_fink_block = false;
         let src = fink_buf.trim_end_matches('\n');
         let highlighted = highlight::highlight(src);
+        let hash = playground::encode_source(src);
+        // Wrap in container with playground link button (external-link icon)
         let html = format!(
-          "<pre class=\"code-block\"><code class=\"language-fink\">{}</code></pre>\n",
-          highlighted
+          "<div class=\"code-block-wrap\">\
+           <a class=\"playground-link\" href=\"/playground/#{hash}\" \
+           title=\"Open in playground\" aria-label=\"Open in playground\">\
+           <svg xmlns=\"http://www.w3.org/2000/svg\" viewBox=\"0 0 135 135\">\
+           <g transform=\"translate(0,3)\">\
+           <path fill=\"currentColor\" d=\"M 7.6,102.4 C 34.3,81.4 46.3,56 57.8,36.3 70.8,14.2 90.6,8.3 111.9,25.6 103.8,25.3 98.5,37.4 84.1,53.9 69.7,70.5 44.6,92.5 7.6,102.4Z\"/>\
+           <path fill=\"currentColor\" d=\"M 97.9,42.1 C 105.6,70.6 101.8,110.8 5.7,115.6 64.5,89.8 93.6,50 97.9,42.1Z\"/>\
+           <path fill=\"#faa343\" d=\"m 102.5,50.9 c -4.6,-22.7 10.2,-26.9 26.5,-21.5 -8.2,2.8 -20.2,8 -26.5,21.5z\"/>\
+           </g></svg></a>\
+           <pre class=\"code-block\"><code class=\"language-fink\">{highlighted}</code></pre>\
+           </div>\n"
         );
         events.push(Event::Html(html.into()));
       }
diff --git a/src/playground.rs b/src/playground.rs
new file mode 100644
index 0000000..bfaf3dc
--- /dev/null
+++ b/src/playground.rs
@@ -0,0 +1,91 @@
+// Playground URL encoder.
+//
+// Encodes source code into a URL hash fragment compatible with the playground's
+// decodeSource(). Pipeline: UTF-8 → deflate-raw → base62.
+
+use std::io::Write;
+use flate2::Compression;
+use flate2::write::DeflateEncoder;
+
+const BASE62: &[u8; 62] = b"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+
+/// Encode source code into a base62 string suitable for a playground URL hash.
+pub fn encode_source(src: &str) -> String {
+  let bytes = src.as_bytes();
+
+  // Deflate-raw compress
+  let mut encoder = DeflateEncoder::new(Vec::new(), Compression::default());
+  encoder.write_all(bytes).expect("deflate write");
+  let compressed = encoder.finish().expect("deflate finish");
+
+  if compressed.is_empty() {
+    return String::from("0");
+  }
+
+  // Count leading zero bytes (preserved as leading '0' digits)
+  let leading_zeros = compressed.iter().take_while(|&&b| b == 0).count();
+
+  // Treat compressed bytes as big-endian unsigned integer
+  let mut n = to_bigint(compressed.as_slice());
+
+  // Convert to base62
+  let mut out = Vec::new();
+  if is_zero(&n) {
+    out.push(BASE62[0]);
+  } else {
+    while !is_zero(&n) {
+      let (quotient, remainder) = div_mod_62(&n);
+      out.push(BASE62[remainder]);
+      n = quotient;
+    }
+  }
+  out.reverse();
+
+  // Prepend leading '0' digits for preserved zero bytes
+  let mut result = String::with_capacity(leading_zeros + out.len());
+  for _ in 0..leading_zeros {
+    result.push('0');
+  }
+  for &b in &out {
+    result.push(b as char);
+  }
+  result
+}
+
+// Big-endian bytes → Vec<u32> limbs (least-significant first) for big integer arithmetic.
+fn to_bigint(bytes: &[u8]) -> Vec<u32> {
+  let mut limbs: Vec<u32> = vec![0];
+  for &b in bytes {
+    // limbs = limbs * 256 + b
+    let mut carry = b as u64;
+    for limb in limbs.iter_mut() {
+      let v = (*limb as u64) * 256 + carry;
+      *limb = v as u32;
+      carry = v >> 32;
+    }
+    if carry > 0 {
+      limbs.push(carry as u32);
+    }
+  }
+  limbs
+}
+
+// Divide big integer (Vec<u32> limbs, LSB first) by 62, return (quotient, remainder).
+fn div_mod_62(limbs: &[u32]) -> (Vec<u32>, usize) {
+  let mut result = vec![0u32; limbs.len()];
+  let mut remainder: u64 = 0;
+  for i in (0..limbs.len()).rev() {
+    let cur = (remainder << 32) | limbs[i] as u64;
+    result[i] = (cur / 62) as u32;
+    remainder = cur % 62;
+  }
+  // Trim leading zero limbs
+  while result.len() > 1 && *result.last().unwrap() == 0 {
+    result.pop();
+  }
+  (result, remainder as usize)
+}
+
+fn is_zero(limbs: &[u32]) -> bool {
+  limbs.iter().all(|&l| l == 0)
+}
diff --git a/static/apple-touch-icon.png b/static/apple-touch-icon.png
deleted file mode 100644
index 705a7dc..0000000
Binary files a/static/apple-touch-icon.png and /dev/null differ
diff --git a/static/favicon-192.png b/static/favicon-192.png
deleted file mode 100644
index 1459f62..0000000
Binary files a/static/favicon-192.png and /dev/null differ
diff --git a/static/favicon-32.png b/static/favicon-32.png
deleted file mode 100644
index 73ba8b1..0000000
Binary files a/static/favicon-32.png and /dev/null differ
diff --git a/static/logo.svg b/static/logo.svg
deleted file mode 100644
index bc3e8a2..0000000
--- a/static/logo.svg
+++ /dev/null
@@ -1,31 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<svg
-   width="500"
-   height="500"
-   viewBox="0 0 135 135"
-   version="1.1"
-   xml:space="preserve"
-   xmlns="http://www.w3.org/2000/svg"
-   xmlns:svg="http://www.w3.org/2000/svg"
->
-  <g transform="translate(0, 3)">
-    <path
-       style="fill:#345e65"
-       d="M 7.5991585,102.41306 C 34.300533,81.435463 46.318437,55.988057 57.811472,36.346974 70.752567,14.231234 90.593352,8.2969824 111.93705,25.616702 103.82049,25.276458 98.49317,37.354838 84.148101,53.872282 69.700471,70.507823 44.56227,92.481987 7.5991585,102.41306 Z"
-       id="body" />
-    <path
-       style="fill:#345e65"
-       d="M 97.852904,42.119144 C 105.64423,70.635971 101.79353,110.79478 5.6643805,115.55219 64.46,89.799518 93.579124,49.95442 97.852904,42.119144 Z"
-       id="belly" />
-    <path
-       style="fill:#faa343;"
-       d="m 102.50472,50.913801 c -4.584599,-22.650221 10.16165,-26.894507 26.5183,-21.47238 -8.23959,2.793409 -20.16491,7.988834 -26.5183,21.47238 z"
-       id="beak"/>
-    <circle
-       style="fill:#ffffff;"
-       id="eye"
-       cx="90.480888"
-       cy="28.07902"
-       r="3.5513237" />
-  </g>
-</svg>
diff --git a/static/social.png b/static/social.png
deleted file mode 100644
index 77d2fb3..0000000
Binary files a/static/social.png and /dev/null differ
diff --git a/static/style.css b/static/style.css
index 93c9662..ee09856 100644
--- a/static/style.css
+++ b/static/style.css
@@ -327,6 +327,24 @@ footer {
 .prose th { background: var(--surface); font-weight: 600; }
 
 /* --- Code blocks -------------------------------------------- */
+.code-block-wrap {
+  position: relative;
+}
+.playground-link {
+  position: absolute;
+  top: 0.5rem;
+  right: 0.5rem;
+  width: 1.25rem;
+  height: 1.25rem;
+  color: var(--text-muted);
+  opacity: 0.2;
+  transition: opacity 0.15s;
+  z-index: 1;
+}
+.code-block-wrap:hover .playground-link { opacity: 0.5; }
+.playground-link:hover { opacity: 1 !important; color: var(--accent); }
+.playground-link svg { width: 100%; height: 100%; display: block; }
+
 pre.code-block {
   background: var(--code-bg);
   color: var(--code-text);
diff --git a/templates/base.html b/templates/base.html
index 3e89e98..c8f949d 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -44,6 +44,7 @@
     <nav>
       <a class="wordmark" href="{{ root }}"><img src="{{ root }}logo.svg" alt="" class="wordmark-logo">ƒink</a>
       <a href="{{ root }}docs/">docs</a>
+      <a href="{{ root }}playground/">playground</a>
       <a href="https://github.com/fink-lang" class="nav-icon" aria-label="GitHub"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="currentColor"><path d="M12 0C5.37 0 0 5.37 0 12c0 5.31 3.435 9.795 8.205 11.385.6.105.825-.255.825-.57 0-.285-.015-1.23-.015-2.235-3.015.555-3.795-.735-4.035-1.41-.135-.345-.72-1.41-1.23-1.695-.42-.225-1.02-.78-.015-.795.945-.015 1.62.87 1.845 1.23 1.08 1.815 2.805 1.305 3.495.99.105-.78.42-1.305.765-1.605-2.67-.3-5.46-1.335-5.46-5.925 0-1.305.465-2.385 1.23-3.225-.12-.3-.54-1.53.12-3.18 0 0 1.005-.315 3.3 1.23.96-.27 1.98-.405 3-.405s2.04.135 3 .405c2.295-1.56 3.3-1.23 3.3-1.23.66 1.65.24 2.88.12 3.18.765.84 1.23 1.905 1.23 3.225 0 4.605-2.805 5.625-5.475 5.925.435.375.81 1.095.81 2.22 0 1.605-.015 2.895-.015 3.3 0 .315.225.69.825.57A12.02 12.02 0 0 0 24 12c0-6.63-5.37-12-12-12z"/></svg></a>
       <div class="theme-picker">
         <button class="theme-toggle" aria-label="Toggle theme" title="Theme">