diff --git a/src/Roux/Html.hs b/src/Roux/Html.hs
index 813c5b8..8ea3f56 100644
--- a/src/Roux/Html.hs
+++ b/src/Roux/Html.hs
@@ -16,14 +16,16 @@ module Roux.Html (
 ) where
 
 import Control.Monad (unless)
+import Data.Aeson (encode)
 import Data.ByteString.Lazy (ByteString)
+import qualified Data.ByteString.Lazy as LB
 import Data.Function ((&))
-import Data.List (sortOn)
 import qualified Data.List.NonEmpty as NE
-import Data.Maybe (catMaybes, fromMaybe, mapMaybe)
+import Data.Maybe (catMaybes, fromMaybe)
 import Data.Ratio (denominator, numerator)
 import Data.Text (Text)
 import qualified Data.Text as T
+import Data.Text.Encoding (decodeUtf8)
 import qualified Text.Blaze.Html.Renderer.Utf8 as R
 import Text.Blaze.Html5 as H
 import Text.Blaze.Html5.Attributes as A
@@ -204,115 +206,155 @@ page title content =
 -- Index page
 -- ---------------------------------------------------------------------------
 
--- | Render the recipe index page.
+-- | Inline JavaScript for client-side search + sort rendering.
+searchJs :: Text
+searchJs = T.unlines
+    [ "(function(){"
+    , "'use strict';"
+    , ""
+    , "const recipes = JSON.parse(document.getElementById('roux-recipe-data').textContent);"
+    , "const errors = JSON.parse(document.getElementById('roux-errors-data').textContent);"
+    , "const listEl = document.getElementById('roux-recipe-list');"
+    , "const searchEl = document.getElementById('roux-search');"
+    , ""
+    , "function getSortMode() {"
+    , "  const h = location.hash.slice(1);"
+    , "  if (h === 'tags') return 'tags';"
+    , "  if (h === 'course') return 'course';"
+    , "  return 'alpha';"
+    , "}"
+    , ""
+    , "function render() {"
+    , "  const query = searchEl.value.toLowerCase().trim();"
+    , "  const mode = getSortMode();"
+    , "  let filtered = recipes;"
+    , "  if (query) {"
+    , "    filtered = recipes.filter(r =>"
+    , "      r.title.toLowerCase().includes(query) ||"
+    , "      r.filename.toLowerCase().includes(query)"
+    , "    );"
+    , "  }"
+    , "  let html = '';"
+    , "  if (query || mode === 'alpha') {"
+    , "    const sorted = [...filtered].sort((a, b) => a.title.localeCompare(b.title));"
+    , "    html = renderFlatList(sorted);"
+    , "  } else if (mode === 'tags') {"
+    , "    html = renderByTags(filtered);"
+    , "  } else if (mode === 'course') {"
+    , "    html = renderByCourse(filtered);"
+    , "  }"
+    , "  if (errors.length > 0) {"
+    , "    html += '<h3>Unparseable recipes</h3><ul>';"
+    , "    errors.forEach(e => { html += '<li>' + escapeHtml(e.title) + '</li>'; });"
+    , "    html += '</ul>';"
+    , "  }"
+    , "  listEl.innerHTML = html;"
+    , "}"
+    , ""
+    , "function renderFlatList(items) {"
+    , "  if (items.length === 0) return '<p>No recipes found.</p>';"
+    , "  let html = '<ul class=\'roux-recipes\'>';"
+    , "  items.forEach(r => {"
+    , "    html += '<li><a href=\"' + encodeURI(r.filename) + '\">' + escapeHtml(r.title) + '</a></li>';"
+    , "  });"
+    , "  html += '</ul>';"
+    , "  return html;"
+    , "}"
+    , ""
+    , "function renderByTags(items) {"
+    , "  const tagMap = {};"
+    , "  items.forEach(r => {"
+    , "    if (r.tags.length === 0) return;"
+    , "    r.tags.forEach(t => {"
+    , "      if (!tagMap[t]) tagMap[t] = [];"
+    , "      tagMap[t].push(r);"
+    , "    });"
+    , "  });"
+    , "  const tags = Object.keys(tagMap).sort((a,b) => a.localeCompare(b));"
+    , "  if (tags.length === 0) return '<p>No tagged recipes.</p>';"
+    , "  let html = '';"
+    , "  tags.forEach(t => {"
+    , "    const sorted = tagMap[t].sort((a,b) => a.title.localeCompare(b.title));"
+    , "    html += '<h3>' + escapeHtml(t) + '</h3>';"
+    , "    html += renderFlatList(sorted);"
+    , "  });"
+    , "  return html;"
+    , "}"
+    , ""
+    , "function renderByCourse(items) {"
+    , "  const courseMap = {};"
+    , "  items.forEach(r => {"
+    , "    if (!r.course) return;"
+    , "    if (!courseMap[r.course]) courseMap[r.course] = [];"
+    , "    courseMap[r.course].push(r);"
+    , "  });"
+    , "  const courses = Object.keys(courseMap).sort((a,b) => a.localeCompare(b));"
+    , "  if (courses.length === 0) return '<p>No recipes with course metadata.</p>';"
+    , "  let html = '';"
+    , "  courses.forEach(c => {"
+    , "    const sorted = courseMap[c].sort((a,b) => a.title.localeCompare(b.title));"
+    , "    html += '<h3>' + escapeHtml(c) + '</h3>';"
+    , "    html += renderFlatList(sorted);"
+    , "  });"
+    , "  return html;"
+    , "}"
+    , ""
+    , "function escapeHtml(s) {"
+    , "  const d = document.createElement('div');"
+    , "  d.appendChild(document.createTextNode(s));"
+    , "  return d.innerHTML;"
+    , "}"
+    , ""
+    , "searchEl.addEventListener('input', render);"
+    , "window.addEventListener('hashchange', render);"
+    , ""
+    , "// Set active tab style based on hash"
+    , "function updateActiveNav() {"
+    , "  const mode = getSortMode();"
+    , "  document.querySelectorAll('.roux-navbar a').forEach(a => {"
+    , "    a.classList.toggle('active', a.getAttribute('href') === '#' + mode);"
+    , "  });"
+    , "}"
+    , "window.addEventListener('hashchange', updateActiveNav);"
+    , ""
+    , "// Initial render"
+    , "if (!location.hash) location.hash = 'alpha';"
+    , "updateActiveNav();"
+    , "render();"
+    , ""
+    , "})();"
+    ]
+
+-- | Render the recipe index page -- shell with embedded JSON + JS rendering.
 indexPage :: SortMode -> [Idx.RecipeInfo] -> ByteString
-indexPage mode recipes =
+indexPage _mode recipes =
     page "Roux — Recipes" $ do
         H.div ! A.class_ "roux-navbar" $ do
             H.ul $ H.li $ H.strong "Roux"
             H.ul $ do
-                H.li $ sortLink "A-Z" AlphaSort "/" mode
-                H.li $ sortLink "By Tag" TagSort "/sorted/tags" mode
-                H.li $ sortLink "By Course" CourseSort "/sorted/course" mode
-        let good = filter (isRight . Idx.riRecipe) recipes
-        case mode of
-            AlphaSort -> renderAlpha good
-            TagSort -> renderByTags good
-            CourseSort -> renderByCourse good
-        -- Show parse errors separately
-        let bad = filter (isLeft . Idx.riRecipe) recipes
-        unless (null bad) $ do
-            H.h3 "Unparseable recipes"
-            H.ul $ mapM_ (H.li . H.toHtml . Idx.riTitle) bad
-
--- | A navigation link for a sort mode, highlighted when active.
-sortLink :: Text -> SortMode -> Text -> SortMode -> Html
-sortLink label linkMode url currentMode =
-    if linkMode == currentMode
-        then H.a ! A.href (H.toValue url) ! A.role "button" ! A.class_ "contrast outline" $ H.toHtml label
-        else H.a ! A.href (H.toValue url) $ H.toHtml label
-
--- | Render recipes sorted alphabetically by title.
-renderAlpha :: [Idx.RecipeInfo] -> Html
-renderAlpha recipes
-    | null recipes = H.p "No recipes found."
-    | otherwise =
-        let sorted = sortOn alphaSortKey recipes
-         in H.ul ! A.class_ "roux-recipes" $ mapM_ recipeItem sorted
-
--- | Render recipes grouped by tags.
-renderByTags :: [Idx.RecipeInfo] -> Html
-renderByTags recipes = do
-    let tags = collectTags recipes
-    if null tags
-        then H.p "No tagged recipes."
-        else mapM_ renderTagGroup tags
+                H.li $ H.a ! A.href "#alpha" $ "A-Z"
+                H.li $ H.a ! A.href "#tags" $ "By Tag"
+                H.li $ H.a ! A.href "#course" $ "By Course"
+        -- Search input
+        H.input
+            ! A.type_ "search"
+            ! A.id "roux-search"
+            ! A.placeholder "Search recipes..."
+            ! A.style "margin-bottom: 1rem;"
+        -- Container for JS-rendered recipe list
+        H.div ! A.id "roux-recipe-list" $ H.p "Loading recipes..."
+        -- Embedded JSON: recipe data
+        H.script ! A.id "roux-recipe-data" ! A.type_ "application/json" $
+            H.toHtml (decodeUtf8 (LB.toStrict (encode (Prelude.map Idx.toSearchEntry (filterOk recipes)))))
+        -- Embedded JSON: error data
+        H.script ! A.id "roux-errors-data" ! A.type_ "application/json" $
+            H.toHtml (decodeUtf8 (LB.toStrict (encode (Prelude.map Idx.toSearchEntry (filterBad recipes)))))
+        -- Inline JS
+        H.script ! A.type_ "text/javascript" $ H.toHtml searchJs
   where
-    collectTags rs =
-        let entries = mapMaybe tagEntries rs
-            allTags = concat entries
-            uniqueTags = sortOn Prelude.id (nubOrd allTags)
-         in [(tag, filter (hasTag tag) rs) | tag <- uniqueTags]
-    tagEntries r = case Idx.riRecipe r of
-        Right recipe ->
-            let tags = metaTags (recipeMetadata recipe)
-             in if null tags then Nothing else Just tags
-        Left _ -> Nothing
-    hasTag tag r = case Idx.riRecipe r of
-        Right recipe -> tag `elem` metaTags (recipeMetadata recipe)
-        Left _ -> False
+    filterOk = filter (isRight . Idx.riRecipe)
+    filterBad = filter (isLeft . Idx.riRecipe)
 
--- | Render recipes grouped by course/category.
-renderByCourse :: [Idx.RecipeInfo] -> Html
-renderByCourse recipes = do
-    let groups = collectCourses recipes
-    if null groups
-        then H.p "No recipes with course metadata."
-        else mapM_ renderCourseGroup groups
-  where
-    collectCourses rs =
-        let entries = mapMaybe courseEntry rs
-            uniqueCourses = sortOn Prelude.id (nubOrd (Prelude.map fst entries))
-         in [(course, [r | r <- rs, courseOf r == Just course]) | course <- uniqueCourses]
-    courseEntry r = case Idx.riRecipe r of
-        Right recipe -> (,) <$> metaCourse (recipeMetadata recipe) <*> pure ()
-        Left _ -> Nothing
-    courseOf r = case Idx.riRecipe r of
-        Right recipe -> metaCourse (recipeMetadata recipe)
-        Left _ -> Nothing
-
--- | Render a group of recipes under a tag heading.
-renderTagGroup :: (Text, [Idx.RecipeInfo]) -> Html
-renderTagGroup (tag, rs) = do
-    H.h3 $ H.toHtml tag
-    H.ul ! A.class_ "roux-recipes" $ mapM_ recipeItem rs
-
--- | Render a group of recipes under a course heading.
-renderCourseGroup :: (Text, [Idx.RecipeInfo]) -> Html
-renderCourseGroup (course, rs) = do
-    H.h3 $ H.toHtml course
-    H.ul ! A.class_ "roux-recipes" $ mapM_ recipeItem rs
-
--- | Render a single recipe link on the index page.
-recipeItem :: Idx.RecipeInfo -> Html
-recipeItem info =
-    H.li $
-        H.a ! A.href (H.toValue ("/recipes/" <> urlEncode (Idx.riFilename info))) $
-            H.toHtml (Idx.riTitle info)
-
--- | Sort key for alphabetical ordering by title, falling back to filename.
-alphaSortKey :: Idx.RecipeInfo -> Text
-alphaSortKey info = case Idx.riRecipe info of
-    Right r -> case metaTitle (recipeMetadata r) of
-        Just t -> t
-        Nothing -> T.pack (takeBaseName (Idx.riFilename info))
-    Left _ -> T.pack "zzzz"
-
--- ---------------------------------------------------------------------------
--- Recipe detail page
--- ---------------------------------------------------------------------------
-
--- | Render a full recipe detail page.
 recipePage :: Idx.RecipeInfo -> ByteString
 recipePage info =
     case Idx.riRecipe info of
@@ -585,10 +627,6 @@ urlDecode t = concat (go [] (T.group t))
 -- Misc helpers
 -- ---------------------------------------------------------------------------
 
--- | Extract base filename without directory components.
-takeBaseName :: FilePath -> String
-takeBaseName = reverse . takeWhile (/= '/') . reverse
-
 -- | Check if an 'Either' is 'Left'.
 isLeft :: Either a b -> Bool
 isLeft (Left _) = True
@@ -598,13 +636,4 @@ isLeft _ = False
 isRight :: Either a b -> Bool
 isRight = not . isLeft
 
-{- | Remove duplicate elements from a list while preserving order of first
-occurrence.
--}
-nubOrd :: (Eq a) => [a] -> [a]
-nubOrd = go []
-  where
-    go _ [] = []
-    go seen (x : xs)
-        | x `elem` seen = go seen xs
-        | otherwise = x : go (x : seen) xs
+