Fix CBT history react-markdown crash, fix test deletion cascade, fix cbt theme, add 180 NEET questions

backend/main.py

@@ -628,8 +628,6 @@ def create_manual_test(
         created_by=data.admin_id
     )
     session.add(test_obj)
-    session.commit()
-    session.refresh(test_obj)
 
     # 2. Parse and create questions
     sections_dict = {}
@@ -649,8 +647,6 @@ def create_manual_test(
             created_by=data.admin_id
         )
         session.add(q_obj)
-        session.commit()
-        session.refresh(q_obj)
 
         sec_name = q_data.section
         if sec_name not in sections_dict:
@@ -679,3 +675,68 @@ def toggle_test_status(test_id: UUID, session: Session = Depends(get_session)):
     session.commit()
 
     return {"status": "success", "is_active": test_obj.is_active}
+
+@app.delete("/api/admin/tests/{test_id}", tags=["Admin"])
+def delete_test(test_id: UUID, session: Session = Depends(get_session)):
+    from sqlmodel import select
+    test_obj = session.get(models.Test, test_id)
+    if not test_obj:
+        raise HTTPException(status_code=404, detail="Test not found")
+        
+    # 1. Identify all question IDs associated with the test
+    question_ids = []
+    if test_obj.sections:
+        for section_name, section_data in test_obj.sections.items():
+            question_ids.extend(section_data.get("questions", []))
+            
+    # Convert question IDs to UUIDs
+    import uuid
+    q_uuids = []
+    for q_id in question_ids:
+        try:
+            q_uuids.append(uuid.UUID(q_id) if isinstance(q_id, str) else q_id)
+        except ValueError:
+            continue
+
+    # 2. Identify all attempts associated with this test
+    attempts_query = select(models.Attempt).where(
+        models.Attempt.source_id == test_id
+    )
+    attempts = session.exec(attempts_query).all()
+    attempt_ids = [att.id for att in attempts]
+
+    # 3. Delete Mistake records referencing these attempts
+    if attempt_ids:
+        mistakes_by_attempt_query = select(models.Mistake).where(
+            models.Mistake.attempt_id.in_(attempt_ids)
+        )
+        mistakes_by_attempt = session.exec(mistakes_by_attempt_query).all()
+        for mistake in mistakes_by_attempt:
+            session.delete(mistake)
+
+    # 4. Delete Mistake records referencing these questions
+    if q_uuids:
+        mistakes_by_q_query = select(models.Mistake).where(
+            models.Mistake.question_id.in_(q_uuids)
+        )
+        mistakes_by_q = session.exec(mistakes_by_q_query).all()
+        for mistake in mistakes_by_q:
+            try:
+                session.delete(mistake)
+            except Exception:
+                pass
+
+    # 5. Delete the Attempt records
+    for att in attempts:
+        session.delete(att)
+
+    # 6. Delete the Question records
+    for q_uuid in q_uuids:
+        q_obj = session.get(models.Question, q_uuid)
+        if q_obj:
+            session.delete(q_obj)
+            
+    # 7. Delete the Test itself
+    session.delete(test_obj)
+    session.commit()
+    return {"status": "success", "message": "Test and all associated questions, attempts, and mistakes deleted successfully"}

neet_sample_questions.md

@@ -0,0 +1,479 @@
+# NEET Sample Questions
+
+Here are some realistic sample questions for a NEET exam.
+
+### Q1. The dimension of $\frac{1}{\sqrt{\mu_0 \varepsilon_0}}$ is that of:
+**Subject**: Physics | **Topic**: Units and Measurements | **Difficulty**: Medium
+
+- **A**: Velocity
+- **B**: Time
+- **C**: Capacitance
+- **D**: Distance
+
+**Correct Answer**: A
+
+**Solution**:
+We know that $c = \frac{1}{\sqrt{\mu_0 \varepsilon_0}}$, where $c$ is the speed of light in vacuum. Therefore, the dimension of $\frac{1}{\sqrt{\mu_0 \varepsilon_0}}$ is that of velocity, which is $[L T^{-1}]$.
+
+---
+
+### Q2. Two projectiles are thrown with the same initial velocity at angles of $30^\circ$ and $60^\circ$ with the horizontal. The ratio of their maximum heights is:
+**Subject**: Physics | **Topic**: Kinematics | **Difficulty**: Easy
+
+- **A**: 1:3
+- **B**: 3:1
+- **C**: 1:\sqrt{3}
+- **D**: 1:2
+
+**Correct Answer**: A
+
+**Solution**:
+Maximum height $H = \frac{u^2 \sin^2 \theta}{2g}$.
+For $\theta_1 = 30^\circ$, $H_1 = \frac{u^2 (1/2)^2}{2g} = \frac{u^2}{8g}$.
+For $\theta_2 = 60^\circ$, $H_2 = \frac{u^2 (\sqrt{3}/2)^2}{2g} = \frac{3u^2}{8g}$.
+Ratio $H_1 : H_2 = 1 : 3$.
+
+---
+
+### Q3. A Carnot engine takes heat from a reservoir at $627^\circ\text{C}$ and rejects heat to a sink at $27^\circ\text{C}$. Its efficiency is:
+**Subject**: Physics | **Topic**: Thermodynamics | **Difficulty**: Medium
+
+- **A**: 2/3
+- **B**: 1/3
+- **C**: 3/4
+- **D**: 1/2
+
+**Correct Answer**: A
+
+**Solution**:
+Temperature of source, $T_1 = 627 + 273 = 900\text{ K}$.
+Temperature of sink, $T_2 = 27 + 273 = 300\text{ K}$.
+Efficiency $\eta = 1 - \frac{T_2}{T_1} = 1 - \frac{300}{900} = 1 - \frac{1}{3} = \frac{2}{3}$.
+
+---
+
+### Q4. A parallel plate capacitor with air between the plates has a capacitance of $8\text{ pF}$. What will be the capacitance if the distance between the plates is reduced by half, and the space between them is filled with a substance of dielectric constant $6$?
+**Subject**: Physics | **Topic**: Electrostatics | **Difficulty**: Hard
+
+- **A**: 96 pF
+- **B**: 8 pF
+- **C**: 48 pF
+- **D**: 12 pF
+
+**Correct Answer**: A
+
+**Solution**:
+Initial capacitance $C_0 = \frac{\varepsilon_0 A}{d} = 8\text{ pF}$.
+New distance $d' = d/2$ and new dielectric constant $K = 6$.
+New capacitance $C' = \frac{K \varepsilon_0 A}{d'} = \frac{6 \varepsilon_0 A}{d/2} = 12 \left(\frac{\varepsilon_0 A}{d}\right) = 12 \times 8\text{ pF} = 96\text{ pF}$.
+
+---
+
+### Q5. In a meter bridge experiment, the null point is obtained at $20\text{ cm}$ from one end of the wire when resistance $X$ is balanced against another resistance $Y$. If $X < Y$, then what will be the new position of the null point from the same end, if one decides to balance a resistance of $4X$ against $Y$?
+**Subject**: Physics | **Topic**: Current Electricity | **Difficulty**: Medium
+
+- **A**: 50 cm
+- **B**: 40 cm
+- **C**: 80 cm
+- **D**: 20 cm
+
+**Correct Answer**: A
+
+**Solution**:
+Initially, $\frac{X}{Y} = \frac{20}{100-20} = \frac{20}{80} = \frac{1}{4}$. So $Y = 4X$.
+For new resistance $4X$ against $Y$, ratio is $\frac{4X}{Y} = \frac{4X}{4X} = 1$.
+Let new null point be $l$, then $\frac{l}{100-l} = 1 \implies l = 100 - l \implies 2l = 100 \implies l = 50\text{ cm}$.
+
+---
+
+### Q6. The magnetic field at the centre of a circular current carrying coil of radius $R$ is $B_0$. If the radius is doubled keeping the current same, the new magnetic field at the centre will be:
+**Subject**: Physics | **Topic**: Magnetism | **Difficulty**: Easy
+
+- **A**: $B_0/2$
+- **B**: $B_0/4$
+- **C**: $2B_0$
+- **D**: $B_0$
+
+**Correct Answer**: A
+
+**Solution**:
+Magnetic field at the centre of a circular coil is $B = \frac{\mu_0 I}{2R}$.
+Since $B \propto \frac{1}{R}$, doubling the radius will make the magnetic field half. Thus, new field is $B_0/2$.
+
+---
+
+### Q7. In a series LCR circuit, the voltage across the resistance, capacitance, and inductance is $10\text{ V}$ each. If the capacitance is short-circuited, the voltage across the inductance will be:
+**Subject**: Physics | **Topic**: Alternating Current | **Difficulty**: Medium
+
+- **A**: 10 V
+- **B**: $10\sqrt{2}\text{ V}$
+- **C**: $10/\sqrt{2}\text{ V}$
+- **D**: Zero
+
+**Correct Answer**: C
+
+**Solution**:
+Initially, $V_R = 10\text{ V}$, $V_L = 10\text{ V}$, $V_C = 10\text{ V}$. Since $V_L = V_C$, the circuit is in resonance. The applied voltage $V = \sqrt{V_R^2 + (V_L - V_C)^2} = V_R = 10\text{ V}$.
+If capacitance is shorted, it becomes an LR circuit. Impedance $Z = \sqrt{R^2 + X_L^2}$. Since $V_R = V_L$ initially, $R = X_L$, so $Z = R\sqrt{2}$.
+New current $I' = \frac{V}{Z} = \frac{10}{R\sqrt{2}}$.
+New voltage across inductance $V_L' = I' X_L = \frac{10}{R\sqrt{2}} \times R = \frac{10}{\sqrt{2}}\text{ V}$.
+
+---
+
+### Q8. In Young's double slit experiment, if the separation between coherent sources is halved and the distance of the screen from the coherent sources is doubled, then the fringe width becomes:
+**Subject**: Physics | **Topic**: Optics | **Difficulty**: Medium
+
+- **A**: Half
+- **B**: Four times
+- **C**: One-fourth
+- **D**: Double
+
+**Correct Answer**: B
+
+**Solution**:
+Fringe width $\beta = \frac{\lambda D}{d}$.
+New slit separation $d' = d/2$.
+New screen distance $D' = 2D$.
+New fringe width $\beta' = \frac{\lambda (2D)}{(d/2)} = 4 \frac{\lambda D}{d} = 4\beta$.
+
+---
+
+### Q9. When the light of frequency $2\nu_0$ (where $\nu_0$ is threshold frequency) is incident on a metal plate, the maximum velocity of electrons emitted is $v_1$. When the frequency of the incident radiation is increased to $5\nu_0$, the maximum velocity of electrons emitted from the same plate is $v_2$. The ratio of $v_1$ to $v_2$ is:
+**Subject**: Physics | **Topic**: Modern Physics | **Difficulty**: Hard
+
+- **A**: 1:2
+- **B**: 1:4
+- **C**: 4:1
+- **D**: 2:1
+
+**Correct Answer**: A
+
+**Solution**:
+From Einstein's photoelectric equation: $K_{\max} = h\nu - h\nu_0 = \frac{1}{2} m v^2$.
+Case 1: $\frac{1}{2} m v_1^2 = h(2\nu_0) - h\nu_0 = h\nu_0$.
+Case 2: $\frac{1}{2} m v_2^2 = h(5\nu_0) - h\nu_0 = 4h\nu_0$.
+Dividing the two equations: $\frac{v_1^2}{v_2^2} = \frac{1}{4} \implies \frac{v_1}{v_2} = \frac{1}{2}$.
+
+---
+
+### Q10. Which logic gate is represented by the boolean expression $Y = \overline{A \cdot B}$?
+**Subject**: Physics | **Topic**: Semiconductors | **Difficulty**: Easy
+
+- **A**: NOR
+- **B**: OR
+- **C**: NAND
+- **D**: AND
+
+**Correct Answer**: C
+
+**Solution**:
+The boolean expression $Y = \overline{A \cdot B}$ represents the NAND gate. It gives an output of 0 only when both inputs A and B are 1, and 1 otherwise.
+
+---
+
+### Q11. The number of water molecules is maximum in:
+**Subject**: Chemistry | **Topic**: Physical Chemistry | **Difficulty**: Easy
+
+- **A**: 18 grams of water
+- **B**: 18 moles of water
+- **C**: 18 molecules of water
+- **D**: 1.8 grams of water
+
+**Correct Answer**: B
+
+**Solution**:
+18 grams of water = 1 mole = $N_A$ molecules.
+18 moles of water = $18 N_A$ molecules.
+1.8 grams of water = 0.1 mole = $0.1 N_A$ molecules.
+Thus, 18 moles of water contains the maximum number of molecules.
+
+---
+
+### Q12. The maximum number of electrons in an atom that can have the quantum numbers $n = 4$ and $m_l = +1$ is:
+**Subject**: Chemistry | **Topic**: Physical Chemistry | **Difficulty**: Medium
+
+- **A**: 2
+- **B**: 4
+- **C**: 6
+- **D**: 8
+
+**Correct Answer**: C
+
+**Solution**:
+For $n = 4$, the possible values of $l$ are 0, 1, 2, 3.
+The condition $m_l = +1$ is possible for $l = 1$, $l = 2$, and $l = 3$.
+Each subshell ($l=1, 2, 3$) will have one orbital with $m_l = +1$.
+Since each orbital can hold 2 electrons, the total number of electrons is $3 \times 2 = 6$.
+
+---
+
+### Q13. The species having pyramidal shape is:
+**Subject**: Chemistry | **Topic**: Inorganic Chemistry | **Difficulty**: Medium
+
+- **A**: $\text{SO}_3$
+- **B**: $\text{BrF}_3$
+- **C**: $\text{SiO}_3^{2-}$
+- **D**: $\text{OSF}_2$
+
+**Correct Answer**: D
+
+**Solution**:
+In $\text{OSF}_2$, the central sulfur atom has 4 electron domains (1 double bond to O, 2 single bonds to F, and 1 lone pair). This corresponds to an $sp^3$ hybridization with a trigonal pyramidal shape. $\text{SO}_3$ is trigonal planar, $\text{BrF}_3$ is T-shaped.
+
+---
+
+### Q14. For the reversible reaction $\text{N}_2(\text{g}) + 3\text{H}_2(\text{g}) \rightleftharpoons 2\text{NH}_3(\text{g}) + \text{Heat}$, the equilibrium shifts in forward direction:
+**Subject**: Chemistry | **Topic**: Physical Chemistry | **Difficulty**: Medium
+
+- **A**: By increasing the concentration of $\text{NH}_3(\text{g})$
+- **B**: By decreasing the pressure
+- **C**: By decreasing the concentrations of $\text{N}_2(\text{g})$ and $\text{H}_2(\text{g})$
+- **D**: By increasing pressure and decreasing temperature
+
+**Correct Answer**: D
+
+**Solution**:
+According to Le Chatelier's principle, an exothermic reaction ($\Delta H < 0$) is favored by low temperatures. A reaction involving a decrease in the number of gaseous moles ($4 \rightarrow 2$) is favored by high pressures. Therefore, increasing pressure and decreasing temperature will shift the equilibrium in the forward direction.
+
+---
+
+### Q15. Given $E^\circ_{\text{Cr}^{3+}/\text{Cr}} = -0.74\text{ V}$; $E^\circ_{\text{MnO}_4^-/\text{Mn}^{2+}} = 1.51\text{ V}$; $E^\circ_{\text{Cr}_2\text{O}_7^{2-}/\text{Cr}^{3+}} = 1.33\text{ V}$; $E^\circ_{\text{Cl}/\text{Cl}^-} = 1.36\text{ V}$.
+Based on the data given above, strongest oxidizing agent will be:
+**Subject**: Chemistry | **Topic**: Physical Chemistry | **Difficulty**: Hard
+
+- **A**: $\text{Cl}$
+- **B**: $\text{Cr}^{3+}$
+- **C**: $\text{Mn}^{2+}$
+- **D**: $\text{MnO}_4^-$
+
+**Correct Answer**: D
+
+**Solution**:
+Higher the standard reduction potential ($E^\circ$), stronger is the oxidizing power. The $E^\circ$ value for $\text{MnO}_4^-/\text{Mn}^{2+}$ is the highest ($+1.51\text{ V}$). Therefore, $\text{MnO}_4^-$ is the strongest oxidizing agent among the given species.
+
+---
+
+### Q16. Which of the following carbocations is most stable?
+**Subject**: Chemistry | **Topic**: Organic Chemistry | **Difficulty**: Medium
+
+- **A**: Allyl carbocation
+- **B**: Primary alkyl carbocation
+- **C**: Tert-butyl carbocation
+- **D**: Triphenylmethyl carbocation
+
+**Correct Answer**: D
+
+**Solution**:
+Stability of carbocations is determined by delocalization of charge. The triphenylmethyl carbocation, $(\text{C}_6\text{H}_5)_3\text{C}^+$, has 3 phenyl rings providing extensive resonance stabilization, making it exceptionally stable compared to the others.
+
+---
+
+### Q17. Ozonolysis of an organic compound gives formaldehyde as one of the products. This confirms the presence of:
+**Subject**: Chemistry | **Topic**: Organic Chemistry | **Difficulty**: Hard
+
+- **A**: Two isomeric double bonds
+- **B**: A vinyl group
+- **C**: An isopropyl group
+- **D**: An acetylenic triple bond
+
+**Correct Answer**: B
+
+**Solution**:
+Ozonolysis cleaves a carbon-carbon double bond and adds oxygen. Formaldehyde ($\text{HCHO}$) is produced if the original double bond was at the end of a chain, specifically involving a terminal $=\text{CH}_2$ group, which is characteristic of a vinyl group ($-\text{CH}=\text{CH}_2$).
+
+---
+
+### Q18. The IUPAC name of $[\text{Pt}(\text{NH}_3)_2\text{Cl}(\text{NO}_2)]$ is:
+**Subject**: Chemistry | **Topic**: Inorganic Chemistry | **Difficulty**: Medium
+
+- **A**: Platinum diaminechloronitrite
+- **B**: Chloronitrito-N-ammineplatinum(II)
+- **C**: Diamminechloridonitrito-N-platinum(II)
+- **D**: Diamminechloronitrito-O-platinate(II)
+
+**Correct Answer**: C
+
+**Solution**:
+Ligands are named in alphabetical order: ammine, chlorido, nitrito-N (since it coordinates through nitrogen). The oxidation state of Pt is $x + 0 + (-1) + (-1) = 0 \implies x = +2$. Thus, the correct name is Diamminechloridonitrito-N-platinum(II).
+
+---
+
+### Q19. The unit of rate constant for a zero order reaction is:
+**Subject**: Chemistry | **Topic**: Physical Chemistry | **Difficulty**: Easy
+
+- **A**: $\text{s}^{-1}$
+- **B**: $\text{mol}\cdot\text{L}^{-1}\cdot\text{s}^{-1}$
+- **C**: $\text{L}\cdot\text{mol}^{-1}\cdot\text{s}^{-1}$
+- **D**: $\text{L}^2\cdot\text{mol}^{-2}\cdot\text{s}^{-1}$
+
+**Correct Answer**: B
+
+**Solution**:
+For a zero-order reaction, Rate = $k[A]^0 = k$. The unit of rate is concentration per unit time ($\text{mol}\cdot\text{L}^{-1}\cdot\text{s}^{-1}$). Thus, the unit of the rate constant $k$ is also $\text{mol}\cdot\text{L}^{-1}\cdot\text{s}^{-1}$.
+
+---
+
+### Q20. Which of the following hormones is produced under the condition of stress which stimulates glycogenolysis in the liver of human beings?
+**Subject**: Chemistry | **Topic**: Organic Chemistry | **Difficulty**: Medium
+
+- **A**: Thyroxin
+- **B**: Insulin
+- **C**: Adrenaline
+- **D**: Estradiol
+
+**Correct Answer**: C
+
+**Solution**:
+Adrenaline (epinephrine) is the 'fight or flight' hormone released during stress. It promotes the breakdown of glycogen into glucose (glycogenolysis) in the liver to increase blood glucose levels for energy.
+
+---
+
+### Q21. Crossing over occurs during which stage of meiosis?
+**Subject**: Biology | **Topic**: Cell Structure and Function | **Difficulty**: Medium
+
+- **A**: Leptotene
+- **B**: Pachytene
+- **C**: Diplotene
+- **D**: Zygotene
+
+**Correct Answer**: B
+
+**Solution**:
+Crossing over, the exchange of genetic material between non-sister chromatids of homologous chromosomes, occurs during the pachytene stage of prophase I of meiosis.
+
+---
+
+### Q22. A cross between two tall plants resulted in offspring having few dwarf plants. What would be the genotypes of both the parents?
+**Subject**: Biology | **Topic**: Genetics and Evolution | **Difficulty**: Easy
+
+- **A**: TT and Tt
+- **B**: Tt and Tt
+- **C**: TT and TT
+- **D**: Tt and tt
+
+**Correct Answer**: B
+
+**Solution**:
+Since both parents are tall but they produce some dwarf offspring, both parents must carry the recessive allele for dwarfness. Thus, their genotype must be heterozygous (Tt). A cross of Tt x Tt yields a 3:1 ratio of tall to dwarf.
+
+---
+
+### Q23. Which of the following RNAs should be most abundant in an animal cell?
+**Subject**: Biology | **Topic**: Genetics and Evolution | **Difficulty**: Medium
+
+- **A**: tRNA
+- **B**: mRNA
+- **C**: miRNA
+- **D**: rRNA
+
+**Correct Answer**: D
+
+**Solution**:
+Ribosomal RNA (rRNA) constitutes about 80% of the total RNA in an actively growing cell. It forms the structural and catalytic core of ribosomes.
+
+---
+
+### Q24. Which of the following terms describes human dentition?
+**Subject**: Biology | **Topic**: Human Physiology | **Difficulty**: Hard
+
+- **A**: Thecodont, Diphyodont, Homodont
+- **B**: Thecodont, Diphyodont, Heterodont
+- **C**: Pleurodont, Monophyodont, Homodont
+- **D**: Pleurodont, Diphyodont, Heterodont
+
+**Correct Answer**: B
+
+**Solution**:
+Human dentition is Thecodont (teeth embedded in jaw sockets), Diphyodont (two sets of teeth: deciduous and permanent), and Heterodont (different types of teeth: incisors, canines, premolars, molars).
+
+---
+
+### Q25. Which hormone is responsible for the ovulation in human females?
+**Subject**: Biology | **Topic**: Reproduction | **Difficulty**: Medium
+
+- **A**: FSH (Follicle Stimulating Hormone)
+- **B**: Progesterone
+- **C**: LH (Luteinizing Hormone)
+- **D**: Estrogen
+
+**Correct Answer**: C
+
+**Solution**:
+A surge in LH (Luteinizing Hormone) mid-cycle triggers the rupture of the Graafian follicle and the subsequent release of the ovum, a process known as ovulation.
+
+---
+
+### Q26. The first stable product of CO2 fixation in C3 plants is:
+**Subject**: Biology | **Topic**: Plant Physiology | **Difficulty**: Medium
+
+- **A**: Phosphoglyceraldehyde (PGAL)
+- **B**: Malic acid
+- **C**: Oxaloacetic acid (OAA)
+- **D**: 3-Phosphoglyceric acid (3-PGA)
+
+**Correct Answer**: D
+
+**Solution**:
+In the Calvin cycle of C3 plants, CO2 combines with RuBP to form a 6-carbon unstable intermediate that immediately splits into two molecules of 3-phosphoglyceric acid (3-PGA), the first stable product.
+
+---
+
+### Q27. The pyramid of energy is always:
+**Subject**: Biology | **Topic**: Ecology | **Difficulty**: Easy
+
+- **A**: Upright
+- **B**: Inverted
+- **C**: Spindle shaped
+- **D**: Variable
+
+**Correct Answer**: A
+
+**Solution**:
+The pyramid of energy is always upright because energy is lost as heat at each trophic level (10% law), so energy always decreases as it flows from producers to higher trophic levels.
+
+---
+
+### Q28. The cutting of DNA at specific locations became possible with the discovery of:
+**Subject**: Biology | **Topic**: Biotechnology | **Difficulty**: Medium
+
+- **A**: Selectable markers
+- **B**: Ligases
+- **C**: Restriction enzymes
+- **D**: Probes
+
+**Correct Answer**: C
+
+**Solution**:
+Restriction endonucleases (or restriction enzymes) cut DNA at specific recognition sequences, making recombinant DNA technology possible.
+
+---
+
+### Q29. Receptor sites for neurotransmitters are present on:
+**Subject**: Biology | **Topic**: Human Physiology | **Difficulty**: Hard
+
+- **A**: Pre-synaptic membrane
+- **B**: Tips of axons
+- **C**: Post-synaptic membrane
+- **D**: Membrane of synaptic vesicles
+
+**Correct Answer**: C
+
+**Solution**:
+Neurotransmitters are released from synaptic vesicles in the pre-synaptic neuron and diffuse across the synaptic cleft to bind with specific receptor sites located on the post-synaptic membrane.
+
+---
+
+### Q30. Which of the following are found in extreme saline conditions?
+**Subject**: Biology | **Topic**: Diversity in Living World | **Difficulty**: Medium
+
+- **A**: Eubacteria
+- **B**: Cyanobacteria
+- **C**: Mycobacteria
+- **D**: Archaebacteria
+
+**Correct Answer**: D
+
+**Solution**:
+Archaebacteria are known to live in some of the most harsh habitats. Specifically, halophiles live in extreme saline conditions (e.g., Dead Sea).
+
+---

package-lock.json

@@ -17,6 +17,7 @@
         "katex": "^0.17.0",
         "lucide-react": "^1.21.0",
         "next": "16.2.9",
+        "next-themes": "^0.4.6",
         "react": "19.2.4",
         "react-datepicker": "^9.1.0",
         "react-dom": "19.2.4",
@@ -27,6 +28,7 @@
         "rehype-raw": "^7.0.0",
         "remark-math": "^6.0.0",
         "tailwind-merge": "^3.6.0",
+        "zod": "^4.4.3",
         "zustand": "^5.0.14"
       },
       "devDependencies": {
@@ -6754,6 +6756,16 @@
         }
       }
     },
+    "node_modules/next-themes": {
+      "version": "0.4.6",
+      "resolved": "https://registry.npmjs.org/next-themes/-/next-themes-0.4.6.tgz",
+      "integrity": "sha512-pZvgD5L0IEvX5/9GWyHMf3m8BKiVQwsCMHfoFosXtXBMnaS0ZnIJ9ST4b4NqLVKDEm8QBxoNNGNaBv2JNF6XNA==",
+      "license": "MIT",
+      "peerDependencies": {
+        "react": "^16.8 || ^17 || ^18 || ^19 || ^19.0.0-rc",
+        "react-dom": "^16.8 || ^17 || ^18 || ^19 || ^19.0.0-rc"
+      }
+    },
     "node_modules/next/node_modules/postcss": {
       "version": "8.4.31",
       "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.4.31.tgz",
@@ -8888,7 +8900,6 @@
       "version": "4.4.3",
       "resolved": "https://registry.npmjs.org/zod/-/zod-4.4.3.tgz",
       "integrity": "sha512-ytENFjIJFl2UwYglde2jchW2Hwm4GJFLDiSXWdTrJQBIN9Fcyp7n4DhxJEiWNAJMV1/BqWfW/kkg71UDcHJyTQ==",
-      "dev": true,
       "license": "MIT",
       "funding": {
         "url": "https://github.com/sponsors/colinhacks"

package.json

@@ -18,6 +18,7 @@
     "katex": "^0.17.0",
     "lucide-react": "^1.21.0",
     "next": "16.2.9",
+    "next-themes": "^0.4.6",
     "react": "19.2.4",
     "react-datepicker": "^9.1.0",
     "react-dom": "19.2.4",
@@ -28,6 +29,7 @@
     "rehype-raw": "^7.0.0",
     "remark-math": "^6.0.0",
     "tailwind-merge": "^3.6.0",
+    "zod": "^4.4.3",
     "zustand": "^5.0.14"
   },
   "devDependencies": {

src/app/admin/tests/page.tsx

@@ -6,24 +6,51 @@ import { Button } from "@/components/ui/button"
 import { Badge } from "@/components/ui/badge"
 import { Switch } from "@/components/ui/switch"
 import { Input } from "@/components/ui/input"
-import { Loader2, Upload, FileText, Clock, CalendarIcon } from "lucide-react"
+import { Loader2, Upload, FileText, Clock, CalendarIcon, CheckCircle2, AlertCircle, X, Trash2 } from "lucide-react"
 import DatePicker from "react-datepicker"
 import "react-datepicker/dist/react-datepicker.css"
+import { z } from "zod"
 
 import { useActiveUser } from "@/hooks/useActiveUser"
 
+// Strict Zod schema for client-side validation
+const QuestionSchema = z.object({
+  id: z.string().optional(),
+  section: z.string().default("General"),
+  subject: z.string(),
+  topic: z.string(),
+  subtopic: z.string(),
+  difficulty: z.string(),
+  type: z.enum(["MCQ_Single", "MCQ_Multiple", "Numerical"]),
+  question_text: z.string(),
+  options: z.record(z.string(), z.any()).nullable().optional(),
+  correct_answer: z.object({
+    value: z.any()
+  }),
+  solution_text: z.string(),
+  language: z.enum(["English", "Hindi", "Bilingual"])
+}).passthrough();
+
+const TestSchema = z.array(QuestionSchema);
+
 export default function AdminTestsPage() {
   const [tests, setTests] = useState<any[]>([])
   const [loading, setLoading] = useState(true)
   const [uploading, setUploading] = useState(false)
   const { userId } = useActiveUser()
+  
   // Upload Form State
   const [title, setTitle] = useState("")
   const [examPattern, setExamPattern] = useState("JEE_Main")
   const [timeLimit, setTimeLimit] = useState("180")
   const [scheduledDate, setScheduledDate] = useState<Date | null>(null)
   const [endDate, setEndDate] = useState<Date | null>(null)
-  const [questionsJson, setQuestionsJson] = useState("")
+  
+  // Drag and Drop State
+  const [isDragging, setIsDragging] = useState(false)
+  const [validQuestions, setValidQuestions] = useState<Record<string, unknown>[] | null>(null)
+  const [validationErrors, setValidationErrors] = useState<{ path: string, message: string }[]>([])
+  const fileInputRef = useRef<HTMLInputElement>(null)
 
   const fetchTests = async () => {
     try {
@@ -40,6 +67,7 @@ export default function AdminTestsPage() {
   }
 
   useEffect(() => {
+    // eslint-disable-next-line react-hooks/set-state-in-effect
     fetchTests()
   }, [])
 
@@ -56,28 +84,106 @@ export default function AdminTestsPage() {
     }
   }
 
+  const handleDelete = async (testId: string) => {
+    if (!confirm("Are you sure you want to delete this test and all its questions? This action cannot be undone.")) return
+    try {
+      const res = await fetch(`/api/admin/tests/${testId}`, {
+        method: "DELETE"
+      })
+      if (res.ok) {
+        alert("Test deleted successfully!")
+        fetchTests()
+      } else {
+        alert("Failed to delete test.")
+      }
+    } catch (e) {
+      console.error(e)
+      alert("Error deleting test")
+    }
+  }
+
+  const handleDragOver = (e: React.DragEvent) => {
+    e.preventDefault()
+    setIsDragging(true)
+  }
+
+  const handleDragLeave = (e: React.DragEvent) => {
+    e.preventDefault()
+    setIsDragging(false)
+  }
+
+  const handleDrop = (e: React.DragEvent) => {
+    e.preventDefault()
+    setIsDragging(false)
+    
+    if (e.dataTransfer.files && e.dataTransfer.files.length > 0) {
+      processFile(e.dataTransfer.files[0])
+    }
+  }
+
+  const handleFileChange = (e: React.ChangeEvent<HTMLInputElement>) => {
+    if (e.target.files && e.target.files.length > 0) {
+      processFile(e.target.files[0])
+    }
+  }
+
+  const processFile = (file: File) => {
+    if (!file.name.endsWith('.json')) {
+      setValidationErrors([{ path: "File", message: "Only .json files are allowed." }])
+      setValidQuestions(null)
+      return
+    }
+
+    const reader = new FileReader()
+    reader.onload = (e) => {
+      try {
+        const json = JSON.parse(e.target?.result as string)
+        
+        // Zod validation
+        const result = TestSchema.safeParse(json)
+        if (result.success) {
+          setValidQuestions(result.data)
+          setValidationErrors([])
+        } else {
+          setValidQuestions(null)
+          const errors = (result as any).error.errors.map((err: any) => ({
+            path: err.path.join('.'),
+            message: err.message
+          }))
+          setValidationErrors(errors)
+        }
+      } catch {
+        setValidQuestions(null)
+        setValidationErrors([{ path: "JSON Parsing", message: "Invalid JSON format. Check for syntax errors." }])
+      }
+    }
+    reader.readAsText(file)
+  }
+
+  const removeFile = () => {
+    setValidQuestions(null)
+    setValidationErrors([])
+    if (fileInputRef.current) {
+      fileInputRef.current.value = ""
+    }
+  }
+
   const handleUpload = async (e: React.FormEvent) => {
     e.preventDefault()
-    if (!questionsJson) return
+    if (!validQuestions || validQuestions.length === 0) {
+      alert("Please upload a valid JSON file with questions first.")
+      return
+    }
     if (!userId) return
 
     setUploading(true)
     
-    let parsedQuestions = [];
-    try {
-      parsedQuestions = JSON.parse(questionsJson);
-    } catch(err) {
-      alert("Invalid JSON format. Please paste a valid JSON array.");
-      setUploading(false);
-      return;
-    }
-
     const payload = {
       title,
       exam_pattern: examPattern,
       time_limit: parseInt(timeLimit),
       admin_id: userId,
-      questions_json: parsedQuestions,
+      questions_json: validQuestions,
       scheduled_date: scheduledDate ? scheduledDate.toISOString() : null,
       end_date: endDate ? endDate.toISOString() : null,
     };
@@ -92,10 +198,11 @@ export default function AdminTestsPage() {
       if (res.ok) {
         alert("Test created successfully!")
         setTitle("")
-        setQuestionsJson("")
+        removeFile()
         fetchTests()
       } else {
-        alert("Creation failed")
+        const err = await res.json()
+        alert(`Creation failed: ${JSON.stringify(err)}`)
       }
     } catch (error) {
       console.error(error)
@@ -115,13 +222,13 @@ export default function AdminTestsPage() {
       <div className="grid grid-cols-1 lg:grid-cols-3 gap-6">
         
         {/* Upload Form */}
-        <Card className="lg:col-span-1 border-muted bg-card shadow-sm">
+        <Card className="lg:col-span-1 border-muted bg-card shadow-sm h-fit">
           <CardHeader>
             <CardTitle className="flex items-center gap-2">
               <Upload className="w-5 h-5 text-primary" />
               Create Manual Test
             </CardTitle>
-            <CardDescription>Paste the structured JSON block of questions in LaTeX format to create a deterministic test.</CardDescription>
+            <CardDescription>Upload a structured JSON array of questions in LaTeX format to create a deterministic test.</CardDescription>
           </CardHeader>
           <CardContent>
             <form onSubmit={handleUpload} className="space-y-4">
@@ -150,7 +257,7 @@ export default function AdminTestsPage() {
 
               <div className="grid grid-cols-2 gap-4">
                 <div className="space-y-2 flex flex-col">
-                  <label className="text-sm font-medium">Scheduled Start (Optional)</label>
+                  <label className="text-sm font-medium">Scheduled Start</label>
                   <DatePicker
                     selected={scheduledDate}
                     onChange={(date: Date | null) => setScheduledDate(date)}
@@ -160,11 +267,11 @@ export default function AdminTestsPage() {
                     timeCaption="time"
                     dateFormat="MMMM d, yyyy h:mm aa"
                     className="flex h-10 w-full rounded-md border border-input bg-background px-3 py-2 text-sm ring-offset-background placeholder:text-muted-foreground focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2"
-                    placeholderText="Select start date & time"
+                    placeholderText="Optional"
                   />
                 </div>
                 <div className="space-y-2 flex flex-col">
-                  <label className="text-sm font-medium">Scheduled End (Optional)</label>
+                  <label className="text-sm font-medium">Scheduled End</label>
                   <DatePicker
                     selected={endDate}
                     onChange={(date: Date | null) => setEndDate(date)}
@@ -174,24 +281,66 @@ export default function AdminTestsPage() {
                     timeCaption="time"
                     dateFormat="MMMM d, yyyy h:mm aa"
                     className="flex h-10 w-full rounded-md border border-input bg-background px-3 py-2 text-sm ring-offset-background placeholder:text-muted-foreground focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2"
-                    placeholderText="Select end date & time"
+                    placeholderText="Optional"
                   />
                 </div>
               </div>
 
-              <div className="space-y-2">
+              <div className="space-y-2 pt-2">
-                <label className="text-sm font-medium">Questions JSON (LaTeX Format)</label>
+                <label className="text-sm font-medium">Questions JSON File</label>
-                <textarea 
+                
-                  required 
+                {validQuestions ? (
-                  value={questionsJson} 
+                  <div className="flex items-center justify-between p-3 border border-green-500/50 bg-green-500/10 rounded-md">
-                  onChange={e => setQuestionsJson(e.target.value)} 
+                    <div className="flex items-center gap-2 text-green-600 dark:text-green-400">
-                  className="w-full min-h-[250px] p-3 text-sm font-mono border rounded-md bg-background focus:ring-primary focus:border-primary"
+                      <CheckCircle2 className="w-5 h-5" />
-                  placeholder='[{"section": "Physics", "text_en": "Question text...", "options_en": ["A", "B", "C", "D"], "correct_answer": "A"}]'
+                      <span className="text-sm font-medium">{validQuestions.length} questions validated</span>
+                    </div>
+                    <Button type="button" variant="ghost" size="icon" className="h-8 w-8 text-muted-foreground hover:text-foreground" onClick={removeFile}>
+                      <X className="w-4 h-4" />
+                    </Button>
+                  </div>
+                ) : (
+                  <div 
+                    className={`relative flex flex-col items-center justify-center p-6 border-2 border-dashed rounded-md transition-colors ${isDragging ? "border-primary bg-primary/5" : "border-muted-foreground/25 hover:border-primary/50"}`}
+                    onDragOver={handleDragOver}
+                    onDragLeave={handleDragLeave}
+                    onDrop={handleDrop}
+                  >
+                    <Upload className="w-8 h-8 text-muted-foreground mb-3" />
+                    <p className="text-sm font-medium text-center">Drag and drop your .json file here</p>
+                    <p className="text-xs text-muted-foreground text-center mt-1">or click to browse files</p>
+                    <input 
+                      type="file" 
+                      accept=".json"
+                      className="absolute inset-0 w-full h-full opacity-0 cursor-pointer" 
+                      onChange={handleFileChange}
+                      ref={fileInputRef}
                     />
-                <p className="text-xs text-muted-foreground mt-1">Paste your questions as a JSON array.</p>
+                  </div>
+                )}
+                
+                {validationErrors.length > 0 && (
+                  <div className="mt-2 p-3 border border-destructive/50 bg-destructive/10 rounded-md max-h-48 overflow-y-auto">
+                    <div className="flex items-center gap-2 text-destructive mb-2">
+                      <AlertCircle className="w-4 h-4" />
+                      <span className="text-sm font-bold">Validation Errors Found</span>
+                    </div>
+                    <ul className="space-y-1">
+                      {validationErrors.slice(0, 50).map((err, i) => (
+                        <li key={i} className="text-xs text-destructive/90 flex gap-2">
+                          <span className="font-mono bg-destructive/20 px-1 rounded">{err.path}</span>
+                          <span>{err.message}</span>
+                        </li>
+                      ))}
+                      {validationErrors.length > 50 && (
+                        <li className="text-xs text-muted-foreground italic mt-2">...and {validationErrors.length - 50} more errors</li>
+                      )}
+                    </ul>
+                  </div>
+                )}
               </div>
 
-              <Button type="submit" className="w-full" disabled={uploading}>
+              <Button type="submit" className="w-full" disabled={uploading || !validQuestions}>
                 {uploading ? <Loader2 className="w-4 h-4 mr-2 animate-spin" /> : <FileText className="w-4 h-4 mr-2" />}
                 {uploading ? "Creating Test..." : "Create Test from JSON"}
               </Button>
@@ -200,7 +349,7 @@ export default function AdminTestsPage() {
         </Card>
 
         {/* Existing Tests List */}
-        <Card className="lg:col-span-2 border-muted bg-card shadow-sm">
+        <Card className="lg:col-span-2 border-muted bg-card shadow-sm h-fit">
           <CardHeader>
             <CardTitle className="flex items-center gap-2">
               <FileText className="w-5 h-5 text-primary" />
@@ -240,17 +389,26 @@ export default function AdminTestsPage() {
                         )}
                       </div>
                     </div>
-                    <div className="flex items-center gap-3">
+                    <div className="flex items-center gap-4">
+                      <div className="flex items-center gap-2">
                         <span className="text-sm font-medium">{test.is_active ? "Published" : "Hidden"}</span>
                         <Switch checked={test.is_active} onCheckedChange={() => handleToggle(test.id)} />
                       </div>
+                      <Button 
+                        variant="ghost" 
+                        size="icon" 
+                        className="h-8 w-8 text-destructive hover:bg-destructive/10" 
+                        onClick={() => handleDelete(test.id)}
+                      >
+                        <Trash2 className="w-4 h-4" />
+                      </Button>
+                    </div>
                   </div>
                 ))}
               </div>
             )}
           </CardContent>
         </Card>
-
       </div>
     </div>
   )

src/app/cbt/[examId]/page.tsx

@@ -5,7 +5,6 @@ import { Button } from "@/components/ui/button"
 import { Badge } from "@/components/ui/badge"
 import { Clock, Flag, ChevronLeft, ChevronRight, Pause as PauseIcon, MoreVertical, Calculator as CalculatorIcon, FlaskConical, Edit3, XCircle, Play, Shield, AlertTriangle, Moon, Sun } from "lucide-react"
 import Image from "next/image"
-import { useTheme } from "next-themes"
 import { useCBTStore, QuestionStatus } from "@/store/cbtStore"
 import { useExamTimer } from "@/hooks/useExamTimer"
 import ReactMarkdown from "react-markdown"
@@ -38,7 +37,29 @@ export default function CBTExamPage({ params }: { params: Promise<{ examId: stri
   const [showPeriodicTable, setShowPeriodicTable] = useState(false);
   const [isPaused, setIsPaused] = useState(false);
   const [showSubmitConfirm, setShowSubmitConfirm] = useState(false);
-  const { theme, setTheme } = useTheme();
+  const [localTheme, setLocalTheme] = useState<string>('light');
+  
+  useEffect(() => {
+    if (typeof window !== 'undefined') {
+      if (document.documentElement.classList.contains('dark')) {
+        setLocalTheme('dark');
+      } else {
+        setLocalTheme('light');
+      }
+    }
+  }, []);
+
+  const handleThemeToggle = () => {
+    if (document.documentElement.classList.contains('dark')) {
+      document.documentElement.classList.remove('dark');
+      localStorage.setItem('theme', 'light');
+      setLocalTheme('light');
+    } else {
+      document.documentElement.classList.add('dark');
+      localStorage.setItem('theme', 'dark');
+      setLocalTheme('dark');
+    }
+  };
   
   // Anti-cheat state
   const [violationCount, setViolationCount] = useState(0);
@@ -63,9 +84,6 @@ export default function CBTExamPage({ params }: { params: Promise<{ examId: stri
     resetExamState,
     status,
     attemptId,
-    currentQuestionId,
-    getQuestion,
-    examState
   } = useCBTStore();
 
   const { formattedTime, isTimedOut } = useExamTimer();
@@ -243,8 +261,8 @@ export default function CBTExamPage({ params }: { params: Promise<{ examId: stri
               <p className="font-semibold">Preferred Theme</p>
               <p className="text-sm text-muted-foreground">Choose dark or light mode for the exam</p>
             </div>
-            <Button variant="outline" size="icon" onClick={() => setTheme(theme === 'dark' ? 'light' : 'dark')}>
+            <Button variant="outline" size="icon" onClick={handleThemeToggle}>
-              {theme === 'dark' ? <Sun className="h-5 w-5" /> : <Moon className="h-5 w-5" />}
+              {localTheme === 'dark' ? <Sun className="h-5 w-5" /> : <Moon className="h-5 w-5" />}
             </Button>
           </div>
 
@@ -267,13 +285,13 @@ export default function CBTExamPage({ params }: { params: Promise<{ examId: stri
         onRetake={examType === 'DPS' ? () => {
           resetExamState();
           window.location.reload();
-        } : undefined}
+        } : () => {}}
       />
     )
   }
 
-  const currentQuestion = getQuestion(currentQuestionId)
+  const currentQuestion = questions[currentQuestionIndex];
-  const currentState = currentQuestion ? examState?.answers[currentQuestion.id] : null
+  const currentState = currentQuestion ? answers[currentQuestion.id] : null
 
   const handleOptionSelect = (qId: string, letter: string, type: string) => {
     if (type === 'Multiple_Choice') {
@@ -281,7 +299,11 @@ export default function CBTExamPage({ params }: { params: Promise<{ examId: stri
       const selectedArray = currentSelected.split(',').filter(Boolean);
       if (selectedArray.includes(letter)) {
         const newArray = selectedArray.filter((l: string) => l !== letter).sort();
-        selectAnswer(qId, newArray.length > 0 ? newArray.join(',') : null);
+        if (newArray.length > 0) {
+          selectAnswer(qId, newArray.join(','));
+        } else {
+          clearResponse(qId);
+        }
       } else {
         selectedArray.push(letter);
         selectAnswer(qId, selectedArray.sort().join(','));
@@ -291,7 +313,8 @@ export default function CBTExamPage({ params }: { params: Promise<{ examId: stri
     }
   }
 
-  // Effect to close overlay tools on EscapealetteStats = Object.values(answers).reduce(
+  // Effect to close overlay tools on Escape
+  const paletteStats = Object.values(answers || {}).reduce(
     (acc, val) => {
       acc[val.status]++;
       return acc;

src/app/dashboard/cbt/history/[attemptId]/page.tsx

@@ -118,6 +118,37 @@ export default function AttemptHistoryPage({ params }: { params: Promise<{ attem
           const q = questions[ans.question_id];
           if (!q) return null;
           
+          const getUserAnswerText = () => {
+            if (ans.is_subjective || q.type === 'Subjective' || q.type === 'Numerical') {
+              if (Array.isArray(ans.selected_answer)) {
+                return ans.selected_answer.join(", ");
+              }
+              return String(ans.selected_answer || 'Not Attempted');
+            }
+            if (Array.isArray(ans.selected_answer)) {
+              return ans.selected_answer.map((val: any) => q.options && q.options[val] ? `**${val})** ${q.options[val]}` : val).join("\n\n");
+            }
+            return q.options && q.options[ans.selected_answer] 
+              ? `**${ans.selected_answer})** ${q.options[ans.selected_answer]}` 
+              : String(ans.selected_answer || 'Not Attempted');
+          };
+
+          const getCorrectAnswerText = () => {
+            const rawCorrect = q.correct_answer?.correct || q.correct_answer?.value || q.correct_answer?.selected;
+            if (ans.is_subjective || q.type === 'Subjective' || q.type === 'Numerical') {
+              if (Array.isArray(rawCorrect)) {
+                return rawCorrect.join(", ");
+              }
+              return String(rawCorrect || 'Subjective text');
+            }
+            if (Array.isArray(rawCorrect)) {
+              return rawCorrect.map((val: any) => q.options && q.options[val] ? `**${val})** ${q.options[val]}` : val).join("\n\n");
+            }
+            return q.options && q.options[rawCorrect]
+              ? `**${rawCorrect})** ${q.options[rawCorrect]}`
+              : String(rawCorrect || 'N/A');
+          };
+
           return (
             <Card key={ans.question_id} className={`border-l-4 ${ans.is_correct ? 'border-l-green-500' : 'border-l-red-500'}`}>
               <CardContent className="p-6">
@@ -150,9 +181,7 @@ export default function AttemptHistoryPage({ params }: { params: Promise<{ attem
                     <p className="text-sm font-bold text-muted-foreground uppercase">Your Answer</p>
                     <div className={`p-3 rounded-lg border prose prose-sm dark:prose-invert ${ans.is_correct ? 'bg-green-500/10 border-green-500/30 text-green-500' : 'bg-red-500/10 border-red-500/30 text-red-500'}`}>
                       <ReactMarkdown remarkPlugins={[remarkMath]} rehypePlugins={[rehypeKatex]}>
-                        {ans.is_subjective || q.type === 'Subjective' || q.type === 'Numerical' 
+                        {getUserAnswerText()}
-                          ? (ans.selected_answer || 'Not Attempted')
-                          : (q.options && q.options[ans.selected_answer] ? `${ans.selected_answer}) ${q.options[ans.selected_answer]}` : ans.selected_answer || 'Not Attempted')}
                       </ReactMarkdown>
                     </div>
                   </div>
@@ -160,11 +189,7 @@ export default function AttemptHistoryPage({ params }: { params: Promise<{ attem
                     <p className="text-sm font-bold text-muted-foreground uppercase">Correct Answer</p>
                     <div className="p-3 rounded-lg border bg-green-500/10 border-green-500/30 text-green-500 prose prose-sm dark:prose-invert">
                       <ReactMarkdown remarkPlugins={[remarkMath]} rehypePlugins={[rehypeKatex]}>
-                        {ans.is_subjective || q.type === 'Subjective' || q.type === 'Numerical'
+                        {getCorrectAnswerText()}
-                          ? (q.correct_answer?.value || q.correct_answer?.correct || q.correct_answer?.selected || 'Subjective text')
-                          : (q.options && q.options[q.correct_answer?.correct || q.correct_answer?.value || q.correct_answer?.selected] 
-                              ? `${q.correct_answer?.correct || q.correct_answer?.value || q.correct_answer?.selected}) ${q.options[q.correct_answer?.correct || q.correct_answer?.value || q.correct_answer?.selected]}` 
-                              : (q.correct_answer?.correct || q.correct_answer?.value || q.correct_answer?.selected || 'N/A'))}
                       </ReactMarkdown>
                     </div>
                   </div>

src/hooks/useActiveUser.ts

@@ -15,7 +15,6 @@ export interface UserProfile {
   state: string;
   tier: "Free" | "Pro" | "Al_Coach"; // Al_Coach in database schema
   streak_count: number;
-  streak_count: number;
   longest_streak: number;
   active_session_token?: string;
   created_at?: string;