diff --git a/_specs/mobile-horizontal-layout.md b/_specs/mobile-horizontal-layout.md
new file mode 100644
index 0000000..f4a75cc
--- /dev/null
+++ b/_specs/mobile-horizontal-layout.md
@@ -0,0 +1,53 @@
+# Spec for mobile-horizontal-layout
+
+branch: claude/feature/mobile-horizontal-layout
+figma_component (if used): N/A
+
+## Summary
+
+When a device screen is less than 1024px wide and in landscape (horizontal) orientation, the `FlashcardSession` view should switch from its current vertical layout to a compact 3-column layout: controls on the left, video in the center, and the term list on the right. The header (`flashcard-session-header` div) should be hidden in this mode to reclaim vertical space.
+
+## Functional Requirements
+
+- Detect when the viewport width is less than 1024px AND the device is in landscape (horizontal) orientation.
+- In that state, hide the `flashcard-session-header` div entirely.
+- Switch the session layout to a 3-column arrangement in this order: controls column | video column | term-list column.
+- Revert to the default layout when the screen is wider than 1024px or switches back to portrait orientation.
+- The layout change must respond dynamically as the user rotates the device (no page reload required).
+- Each column should be appropriately sized so all three are visible without horizontal scrolling.
+- The video column should take the most space, with controls and term list given narrower fixed or proportional widths.
+
+## Possible Edge Cases
+
+- Device rotates while a card is being shown — the active card and playback state should be preserved.
+- Very narrow landscape screens (e.g. older phones) where 3 columns may still be tight — columns should not overflow; use overflow hidden or scroll per column as appropriate.
+- User resizes a desktop browser window to below 1024px while in a non-landscape orientation — the 3-column layout should NOT activate; it requires both conditions simultaneously.
+- Term list with many items in the narrow right column — the column should scroll independently.
+
+## Acceptance Criteria
+
+- [ ] On a device or browser window narrower than 1024px in landscape orientation, the `flashcard-session-header` div is not visible.
+- [ ] On a device or browser window narrower than 1024px in landscape orientation, the session displays three side-by-side columns: controls | video | term list.
+- [ ] Rotating back to portrait (or resizing above 1024px) restores the original layout and re-shows the header.
+- [ ] No horizontal scrollbar appears in the 3-column layout.
+- [ ] Active flashcard state is preserved through orientation changes.
+- [ ] The 3-column layout does not activate on a portrait screen narrower than 1024px.
+
+## Open Questions
+
+- Should the controls column show all existing controls (navigation buttons, color picker, etc.) or a reduced set to save space?
+  - reduces set to save space
+- Should the term list column be scrollable independently or clipped?
+  - independently
+- Is there a minimum height required before the 3-column layout kicks in, in addition to the width and orientation check?
+  - Optimize so the video is the largest it can be
+
+## Testing Guidelines
+
+Create a test file(s) in the ./tests folder for the new feature, and create meaningful tests for the following cases, without going too heavy:
+
+- Verify that the `flashcard-session-header` is hidden when width < 1024px and orientation is landscape.
+- Verify that the `flashcard-session-header` is visible when width >= 1024px regardless of orientation.
+- Verify that the `flashcard-session-header` is visible when orientation is portrait and width < 1024px.
+- Verify that the 3-column layout class or style is applied under the mobile-landscape condition.
+- Verify that the default layout is restored when orientation changes back to portrait.
diff --git a/src/App.css b/src/App.css
index 1241c7b..c7aea02 100644
--- a/src/App.css
+++ b/src/App.css
@@ -607,6 +607,75 @@
   }
 }
 
+/* ── Mobile landscape 3-column layout ────────────────── */
+
+.fcs-landscape {
+  display: grid;
+  grid-template-columns: 120px 1fr 140px;
+  gap: 8px;
+  flex-grow: 1;
+  min-height: 0;
+  overflow: hidden;
+}
+
+.fcs-landscape__controls {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+  overflow: hidden;
+}
+
+.fcs-landscape__controls .flashcard-card {
+  flex: 1 1 0;
+  min-height: 40px;
+  max-width: 100%;
+  border-radius: 10px;
+  padding: 8px;
+}
+
+.fcs-landscape__controls .flashcard-term {
+  font-size: clamp(14px, 3vw, 24px);
+}
+
+.fcs-landscape__video {
+  display: flex;
+  align-items: stretch;
+  overflow: hidden;
+}
+
+.fcs-landscape__video .flashcard-video {
+  width: 100%;
+  max-width: 100%;
+  aspect-ratio: unset;
+  flex: 1 1 0;
+  min-height: 0;
+}
+
+.fcs-landscape__termlist {
+  overflow-y: auto;
+  overflow-x: hidden;
+  display: flex;
+  flex-direction: column;
+}
+
+.fcs-landscape__termlist .term-select {
+  flex-grow: 1;
+  overflow-y: auto;
+  font-size: 13px;
+}
+
+.fcs-landscape__nav {
+  display: flex;
+  flex-direction: column;
+  gap: 6px;
+}
+
+.fcs-landscape__nav .btn-nav {
+  padding: 6px 10px;
+  font-size: 13px;
+  width: 100%;
+}
+
 /* ── App banner ───────────────────────────────────────── */
 
 .app-banner {
diff --git a/src/components/FlashcardSession.jsx b/src/components/FlashcardSession.jsx
index ecbfca2..6128c12 100644
--- a/src/components/FlashcardSession.jsx
+++ b/src/components/FlashcardSession.jsx
@@ -9,8 +9,24 @@ export function FlashcardSession({terms, cardColors, onBack, title, description}
     const [localTerms, setLocalTerms] = useState(terms);
     const [localColors, setLocalColors] = useState(cardColors);
     const [termDrawerOpen, setTermDrawerOpen] = useState(false);
+    const [isMobileHorizontal, setIsMobileHorizontal] = useState(false);
     const selectRef = useRef(null);
 
+    useEffect(() => {
+        function check() {
+            setIsMobileHorizontal(
+                window.innerWidth < 1024 && window.matchMedia('(orientation: landscape)').matches
+            );
+        }
+        check();
+        window.addEventListener('resize', check);
+        window.addEventListener('orientationchange', check);
+        return () => {
+            window.removeEventListener('resize', check);
+            window.removeEventListener('orientationchange', check);
+        };
+    }, []);
+
     const goNext = useCallback(() => {
         setCurrentIndex(i => (i + 1) % localTerms.length);
     }, [localTerms.length]);
@@ -72,6 +88,63 @@ export function FlashcardSession({terms, cardColors, onBack, title, description}
     const fg = contrastColor(bg);
     const playbackUrl = getPlaybackUrl();
 
+    if (isMobileHorizontal) {
+        return (
+            <div className="flashcard-session">
+                <div className="fcs-landscape">
+                    <div className="fcs-landscape__controls">
+                        <button className="btn-back" onClick={onBack}>← Back</button>
+                        <div className="flashcard-card" style={{backgroundColor: bg, color: fg}}>
+                            <span className="flashcard-term">{localTerms[currentIndex].term}</span>
+                        </div>
+                        <p className="flashcard-position">{currentIndex + 1} / {localTerms.length}</p>
+                        <div className="flashcard-nav fcs-landscape__nav">
+                            <button className="btn-nav" onClick={goPrev}>← Prev</button>
+                            <button className="btn-nav" onClick={goNext}>Next →</button>
+                            <button className="btn-nav" onClick={handleShuffle}>⇄ Shuffle</button>
+                        </div>
+                    </div>
+                    <div className="fcs-landscape__video">
+                        <div className="flashcard-video">
+                            {playbackUrl ? (
+                                <ReactPlayer
+                                    className="flashcard-video-iframe"
+                                    title="ASL sign video"
+                                    src={playbackUrl}
+                                    autoPlay={true}
+                                    controls={true}
+                                    muted={true}
+                                    width="100%"
+                                    height="100%"
+                                    onError={playbackError}
+                                />
+                            ) : (
+                                <div className="flashcard-video-placeholder">
+                                    No video available
+                                </div>
+                            )}
+                        </div>
+                    </div>
+                    <div className="fcs-landscape__termlist">
+                        <select
+                            ref={selectRef}
+                            size={20}
+                            className="term-select"
+                            onChange={e => setCurrentIndex(Number(e.target.value))}
+                            value={currentIndex}
+                        >
+                            {sortedTerms.map(({term, i, fix}) => (
+                                <option key={i} value={i} className={fix ? 'term-option--needs-fix' : undefined}>
+                                    {fix ? `[fix] ${term}` : term}
+                                </option>
+                            ))}
+                        </select>
+                    </div>
+                </div>
+            </div>
+        );
+    }
+
     return (
         <div className="flashcard-session">
             <button className="btn-back" onClick={onBack}>← Back</button>
diff --git a/src/components/TermInput.jsx b/src/components/TermInput.jsx
index 4169da5..9e0af2d 100644
--- a/src/components/TermInput.jsx
+++ b/src/components/TermInput.jsx
@@ -11,9 +11,9 @@ import color_terms from "../data/colors.json";
 import faire_terms from "../data/faire.json";
 import axios from "axios";
 
+const DEVELOPMENT = false;
+
 const CATEGORIES = [
-    {icon: "🖐️", title: "Finger Spelling", description: "Practice spelling words letter by letter using ASL handshapes.", terms: terms},
-    {icon: "🔢", title: "Numbers", description: "Learn to sign numbers in American Sign Language.", terms: terms},
     {icon: "📚", title: "ASL Level I & II Class Terms", description: "Core vocabulary from ASL Level I and II coursework.", terms: terms},
     {icon: "❓", title: "Questions", description: "Essential question words and phrases used in ASL conversation.", terms: questions},
     {icon: "⚡", title: "Verbs", description: "Common action words and verbs in American Sign Language.", terms: verbs},
@@ -23,6 +23,21 @@ const CATEGORIES = [
     {icon: "🎨", title: "Colors", description: "Various Colors", terms: color_terms},
 ];
 
+if (DEVELOPMENT) {
+    CATEGORIES.splice(0, 0, {
+        icon: "🖐️",
+        title: "Finger Spelling",
+        description: "Practice spelling words letter by letter using ASL handshapes.",
+        terms: terms
+    });
+    CATEGORIES.splice(0, 0, {
+        icon: "🔢",
+        title: "Numbers",
+        description: "Learn to sign numbers in American Sign Language.",
+        terms: terms
+    });
+}
+
 const webResources = [
     {url: "https://www.signasl.org/", description: "Sign ASL - American Sign Language Dictionary", type: ""},
     {url: "https://www.handspeak.com/", description: "Hand Speak", type: ""},
@@ -37,38 +52,42 @@ export function TermInput({onStart}) {
     const [numberList, setNumberList] = useState([]);
 
     useEffect(() => {
-        // load random words
-        const randomWordsUrl = "https://random-word-api.herokuapp.com/word?number=45";
-        axios.get(randomWordsUrl).then((response) => {
-            const wordData = [];
-            response.data.forEach(element => {
-                const entry = {
-                    "term": element,
-                    "code": "",
-                    "type": "spell"
-                };
-                wordData.push(entry);
+        if (DEVELOPMENT) {
+            // load random words
+            const randomWordsUrl = "https://random-word-api.herokuapp.com/word?number=45";
+            axios.get(randomWordsUrl).then((response) => {
+                const wordData = [];
+                response.data.forEach(element => {
+                    const entry = {
+                        "term": element,
+                        "code": "",
+                        "type": "spell"
+                    };
+                    wordData.push(entry);
+                });
+                setWordlist(wordData);
             });
-            setWordlist(wordData);
-        });
 
-        const randomNumbersUrl = "https://api.codetabs.com/v1/random/integer?min=1&max=9999&times=45";
-        axios.get(randomNumbersUrl).then((response) => {
-            const numberData = [];
-            response.data.data.forEach(element => {
-                const entry = {
-                    "term": element.toString(),
-                    "code": ""
-                };
-                numberData.push(entry);
+            const randomNumbersUrl = "https://api.codetabs.com/v1/random/integer?min=1&max=9999&times=45";
+            axios.get(randomNumbersUrl).then((response) => {
+                const numberData = [];
+                response.data.data.forEach(element => {
+                    const entry = {
+                        "term": element.toString(),
+                        "code": ""
+                    };
+                    numberData.push(entry);
+                });
+                setNumberList(numberData);
             });
-            setNumberList(numberData);
-        });
+        }
     }, []);
 
     useEffect(() => {
-        CATEGORIES.find((category) => category.title === "Numbers").terms = numberList;
-        CATEGORIES.find((category) => category.title === "Finger Spelling").terms = wordlist;
+        if (DEVELOPMENT) {
+            CATEGORIES.find((category) => category.title === "Numbers").terms = numberList;
+            CATEGORIES.find((category) => category.title === "Finger Spelling").terms = wordlist;
+        }
     }, [wordlist, numberList]);
 
     function handleStart(category) {