from reportlab.lib.pagesizes import A4
from reportlab.lib import colors
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import cm
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle,
    HRFlowable, PageBreak, KeepTogether
)
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY
from reportlab.platypus import BaseDocTemplate, Frame, PageTemplate
from reportlab.lib.colors import HexColor

# ── Color palette ─────────────────────────────────────────────────────────────
C_DARK_BLUE   = HexColor("#1A237E")
C_MED_BLUE    = HexColor("#1565C0")
C_LIGHT_BLUE  = HexColor("#E3F2FD")
C_ACCENT      = HexColor("#F57F17")
C_GREEN       = HexColor("#1B5E20")
C_GREEN_LIGHT = HexColor("#E8F5E9")
C_RED         = HexColor("#B71C1C")
C_RED_LIGHT   = HexColor("#FFEBEE")
C_GREY_BG     = HexColor("#F5F5F5")
C_WHITE       = colors.white
C_BLACK       = colors.black

# ── Document setup ─────────────────────────────────────────────────────────────
OUTPUT = "/tmp/workspace/neet-pg-revision/NEET_PG_Top50_High_Yield.pdf"
doc = SimpleDocTemplate(
    OUTPUT,
    pagesize=A4,
    rightMargin=1.8*cm, leftMargin=1.8*cm,
    topMargin=2*cm, bottomMargin=2*cm,
    title="NEET PG – Top 50 High-Yield Topics",
    author="Orris AI"
)

styles = getSampleStyleSheet()

# Custom styles
TITLE_STYLE = ParagraphStyle("TitleS", parent=styles["Title"],
    fontSize=26, textColor=C_WHITE, alignment=TA_CENTER,
    spaceAfter=6, fontName="Helvetica-Bold")

SUBTITLE_STYLE = ParagraphStyle("SubtitleS", parent=styles["Normal"],
    fontSize=12, textColor=C_LIGHT_BLUE, alignment=TA_CENTER,
    spaceAfter=4, fontName="Helvetica")

SUBJECT_HEADER = ParagraphStyle("SubjH", parent=styles["Heading1"],
    fontSize=14, textColor=C_WHITE, fontName="Helvetica-Bold",
    spaceAfter=2, spaceBefore=10, alignment=TA_LEFT,
    leftIndent=6)

TOPIC_NUM = ParagraphStyle("TopicNum", parent=styles["Normal"],
    fontSize=11, textColor=C_WHITE, fontName="Helvetica-Bold",
    alignment=TA_CENTER)

TOPIC_NAME = ParagraphStyle("TopicName", parent=styles["Normal"],
    fontSize=13, textColor=C_DARK_BLUE, fontName="Helvetica-Bold",
    spaceAfter=3, spaceBefore=2)

ONE_LINER_LABEL = ParagraphStyle("OLL", parent=styles["Normal"],
    fontSize=9, textColor=C_ACCENT, fontName="Helvetica-Bold",
    spaceAfter=1)

ONE_LINER_TEXT = ParagraphStyle("OLT", parent=styles["Normal"],
    fontSize=11, textColor=C_RED, fontName="Helvetica-Bold",
    spaceAfter=6, leftIndent=8)

DETAIL_LABEL = ParagraphStyle("DL", parent=styles["Normal"],
    fontSize=9, textColor=C_MED_BLUE, fontName="Helvetica-Bold",
    spaceAfter=1)

DETAIL_TEXT = ParagraphStyle("DT", parent=styles["Normal"],
    fontSize=10, textColor=C_BLACK, fontName="Helvetica",
    spaceAfter=4, leftIndent=8, leading=14, alignment=TA_JUSTIFY)

BULLET_STYLE = ParagraphStyle("BS", parent=styles["Normal"],
    fontSize=10, textColor=C_BLACK, fontName="Helvetica",
    leftIndent=16, spaceAfter=2, leading=13,
    bulletIndent=8)

TOC_STYLE = ParagraphStyle("TOCS", parent=styles["Normal"],
    fontSize=10, textColor=C_DARK_BLUE, fontName="Helvetica",
    spaceAfter=2, leftIndent=8)

PAGE_NOTE = ParagraphStyle("PN", parent=styles["Normal"],
    fontSize=8, textColor=HexColor("#757575"), fontName="Helvetica",
    alignment=TA_CENTER)

# ── Topic data ─────────────────────────────────────────────────────────────────
# Each entry: (number, subject, topic_name, one_liner, detailed_explanation, bullets)
TOPICS = [
    # ── ANATOMY ──────────────────────────────────────────────────────────────
    (1, "ANATOMY", "Dermatomes & Myotomes",
     "C5 – shoulder abduction; L4 – knee extension; S1 – plantar flexion.",
     "Dermatomes are skin areas supplied by a single spinal nerve. Myotomes are muscle groups controlled by one spinal segment. Clinical testing maps neurological deficits to cord levels, guiding diagnosis of disc prolapses and cord injuries.",
     ["C5: Deltoid (abduction) | Biceps reflex",
      "C6: Wrist extension | Brachioradialis reflex",
      "C7: Wrist/finger extension | Triceps reflex",
      "L3-L4: Quadriceps (knee extension) | Knee jerk",
      "S1: Plantar flexion, eversion | Ankle jerk",
      "L4-L5: Dorsiflexion of foot (L4 = tibialis anterior)"]),

    (2, "ANATOMY", "Structures Passing Through Foramina",
     "Foramen ovale: V3; Foramen rotundum: V2; Foramen spinosum: middle meningeal artery.",
     "Knowledge of foraminal contents is high-yield for skull base anatomy questions. Damage to specific foramina produces predictable cranial nerve palsies.",
     ["Superior orbital fissure: CN III, IV, V1, VI + ophthalmic veins",
      "Jugular foramen: CN IX, X, XI + sigmoid sinus → IJV",
      "Hypoglossal canal: CN XII",
      "Foramen magnum: medulla, vertebral arteries, CN XI (spinal root)",
      "Internal acoustic meatus: CN VII, VIII"]),

    (3, "ANATOMY", "Femoral Triangle",
     "Contents (lateral → medial): NAVY – Nerve, Artery, Vein, Y-fronts (empty space/canal).",
     "The femoral triangle is bounded by the inguinal ligament (superiorly), sartorius (laterally), and adductor longus (medially). The femoral sheath encloses artery, vein, and canal (not the nerve). The femoral nerve lies outside the sheath.",
     ["Femoral nerve – most lateral, outside femoral sheath",
      "Femoral artery – central in sheath",
      "Femoral vein – medial to artery",
      "Femoral canal – most medial, contains lymphatics (Cloquet's node)",
      "Femoral hernia passes through the femoral canal"]),

    # ── PHYSIOLOGY ────────────────────────────────────────────────────────────
    (4, "PHYSIOLOGY", "Cardiac Action Potential Phases",
     "Phase 0=rapid depolarisation (Na+); Phase 2=plateau (Ca2+); Phase 3=repolarisation (K+).",
     "The ventricular action potential has 5 phases. Phase 0 rapid Na+ influx; Phase 1 early repolarisation (K+ out, Cl- in); Phase 2 plateau sustained by L-type Ca2+ channels balanced by K+ efflux; Phase 3 rapid repolarisation by K+ efflux; Phase 4 resting membrane potential (−90 mV). SA node lacks phase 1 and has automatic phase 4 depolarisation.",
     ["Longest phase is Phase 2 (plateau) – prevents tetany of heart",
      "Absolute refractory period = Phase 0, 1, 2, and most of Phase 3",
      "SA node pacemaker: funny current (If) – Na+ mediated",
      "Drugs targeting phases: Class I (Na+), Class III (K+), Class IV (Ca2+)",
      "QT interval correlates with Phase 2 + Phase 3"]),

    (5, "PHYSIOLOGY", "Starling's Law of the Heart",
     "Increased venous return → increased sarcomere stretch → increased stroke volume.",
     "Frank-Starling mechanism states that stroke volume is proportional to end-diastolic volume (preload). Myosin-actin overlap is optimised at sarcomere length 2.2 µm. Beyond this, force generation falls (descending limb). This mechanism allows the heart to eject whatever venous blood it receives without external nervous input.",
     ["Preload ↑ → EDV ↑ → SV ↑",
      "Afterload ↑ (e.g. hypertension) → SV ↓",
      "Contractility (inotropy) shifts the Starling curve upward",
      "Clinical: heart failure – operating on descending limb",
      "Optimal sarcomere length ≈ 2.2 µm"]),

    (6, "PHYSIOLOGY", "Spirometry Values (Normal Adult)",
     "FEV1/FVC >0.8 normal; <0.7 = obstruction; Normal FEV1/FVC with low FVC = restriction.",
     "Forced Vital Capacity (FVC) is the total air forcibly expelled. FEV1 is the volume in 1 second. The ratio distinguishes obstructive (asthma, COPD) from restrictive (fibrosis, obesity) disease. TLC is increased in obstruction and decreased in restriction.",
     ["FVC: 4–5 L (male), 3–4 L (female)",
      "FEV1: ~80% of FVC normally",
      "Obstructive: ↓ FEV1, normal/↑ FVC, ↓ FEV1/FVC, ↑ TLC",
      "Restrictive: ↓ FVC, normal FEV1/FVC, ↓ TLC",
      "Dead space (anatomical): ~150 mL",
      "Closing volume: small airway closure – ↑ with age"]),

    # ── BIOCHEMISTRY ──────────────────────────────────────────────────────────
    (7, "BIOCHEMISTRY", "Enzyme Inhibition Types",
     "Competitive: raises Km, same Vmax. Non-competitive: same Km, lowers Vmax.",
     "Enzyme kinetics are tested extensively. In competitive inhibition, the inhibitor resembles the substrate and competes for the active site; increasing substrate concentration can overcome it. Non-competitive inhibitors bind allosteric sites and cannot be overcome by substrate. Uncompetitive inhibitors only bind the enzyme-substrate complex, lowering both Km and Vmax.",
     ["Competitive: ↑ apparent Km, unchanged Vmax",
      "Non-competitive: unchanged Km, ↓ Vmax",
      "Uncompetitive: ↓ Km and ↓ Vmax (parallel line shift on Lineweaver-Burk)",
      "Methotrexate: competitive inhibitor of DHFR",
      "Aspirin: irreversible (covalent) inhibitor of COX",
      "Lineweaver-Burk plot: 1/v vs 1/[S]"]),

    (8, "BIOCHEMISTRY", "Glycolysis Key Enzymes",
     "Rate-limiting enzyme of glycolysis is Phosphofructokinase-1 (PFK-1).",
     "Glycolysis converts glucose (6C) to 2 pyruvate (3C), generating net 2 ATP and 2 NADH. Three irreversible steps: Hexokinase (glucose→G6P), PFK-1 (F6P→F1,6BP), and Pyruvate kinase. PFK-1 is allosterically inhibited by ATP/citrate and activated by AMP/F2,6BP.",
     ["Net ATP yield: 2 ATP per glucose",
      "PFK-1 inhibited by: ATP, citrate (+ = AMP, F2,6BP)",
      "Pyruvate kinase deficiency → hemolytic anemia",
      "G6PD deficiency → Heinz bodies, bite cells on smear",
      "Fructose bypasses PFK-1 (dietary excess → fat)",
      "Warburg effect: cancer cells prefer aerobic glycolysis"]),

    (9, "BIOCHEMISTRY", "Collagen Synthesis Steps",
     "Hydroxyproline and hydroxylysine synthesis requires Vitamin C (ascorbic acid).",
     "Collagen is the most abundant protein in the body. Synthesis: transcription → pre-procollagen → procollagen (in RER, hydroxylation of Pro/Lys by prolyl/lysyl hydroxylase requiring Vit C and Fe2+) → triple helix formation → extracellular cleavage → fibrillogenesis (cross-linking by lysyl oxidase requiring Cu2+).",
     ["Vit C deficiency → scurvy: perifollicular hemorrhages, poor wound healing",
      "Osteogenesis imperfecta: Type I collagen mutation → brittle bones",
      "Ehlers-Danlos: collagen structural/processing defect → hyperextensible skin",
      "Menkes disease: Cu2+ deficiency → lysyl oxidase failure → kinky hair",
      "Type I: bone, skin, tendon | Type II: cartilage | Type III: blood vessels | Type IV: basement membrane"]),

    # ── PATHOLOGY ─────────────────────────────────────────────────────────────
    (10, "PATHOLOGY", "Cell Injury & Necrosis Types",
     "Coagulative necrosis = most organs; Liquefactive = brain/abscess; Caseous = TB.",
     "Cell injury mechanisms: ATP depletion, free radical injury, Ca2+ influx, membrane damage. Reversible: cell swelling, fatty change. Irreversible: nuclear changes (pyknosis→karyorrhexis→karyolysis). Necrosis types are determined by which enzymes and tissue architecture prevail.",
     ["Coagulative: ischemic infarcts (except brain) – architecture preserved",
      "Liquefactive: brain infarcts, bacterial abscesses (proteases dominate)",
      "Caseous: TB/fungi –'cottage cheese', surrounded by granuloma",
      "Fat necrosis: pancreatitis/breast trauma – saponification (Ca soap deposits)",
      "Fibrinoid: immune complex vasculitis, malignant hypertension",
      "Gangrenous: limb ischemia; Wet gangrene = superimposed infection"]),

    (11, "PATHOLOGY", "Inflammatory Cells & Their Roles",
     "Neutrophils first (0-2 days); Macrophages replace them (days 2-7); Lymphocytes in chronic.",
     "Acute inflammation hallmarks: rubor, tumor, calor, dolor, functio laesa. Mediators: histamine (early), prostaglandins, leukotrienes, cytokines. Chronic inflammation: macrophages, lymphocytes, plasma cells, granuloma formation.",
     ["Neutrophils: first responders, pus cells, multilobed nucleus",
      "Eosinophils: parasites, allergic reactions, Charcot-Leyden crystals",
      "Mast cells: degranulate on IgE crosslinking → histamine release",
      "Macrophages: CD68+, phagocytosis, IL-1/TNF/IL-12 production",
      "Giant cells: Langhans (TB), Foreign body, Touton (fat necrosis)",
      "Plasma cells: produce antibodies, clock-face chromatin, Russell bodies"]),

    (12, "PATHOLOGY", "Tumour Markers",
     "AFP: HCC/germ cell; CEA: colorectal; PSA: prostate; CA-125: ovarian; CA 19-9: pancreatic.",
     "Tumour markers are used for monitoring treatment response, not screening (low specificity). They are produced by tumour cells or host response. A rise after treatment suggests recurrence.",
     ["AFP: Hepatocellular carcinoma, Yolk sac tumour, Neural tube defects (maternal AFP)",
      "CEA: Colorectal, lung, breast, pancreatic cancer",
      "PSA: Prostate cancer – elevated also in BPH, prostatitis",
      "CA-125: Epithelial ovarian cancer, endometriosis",
      "CA 19-9: Pancreatic, biliary cancer",
      "Beta-hCG: Choriocarcinoma, hydatidiform mole, testicular (non-seminoma)",
      "LDH: Non-specific – Seminoma, lymphoma, haemolysis",
      "S-100: Melanoma, schwannoma, Langerhans cell histiocytosis"]),

    (13, "PATHOLOGY", "Granuloma Forming Conditions",
     "SARCOIDOSIS – non-caseating; TB – caseating granuloma with central necrosis.",
     "A granuloma is a collection of activated macrophages (epithelioid cells) ± multinucleate giant cells, typically surrounded by lymphocytes. Formation requires T-cell mediated (Type IV) hypersensitivity and persistent antigen.",
     ["Non-caseating: Sarcoidosis, Crohn's disease, Berylliosis, foreign body",
      "Caseating: TB (Mycobacterium), Histoplasma, Coccidioides",
      "Sarcoid granuloma: Schaumann bodies (calcified), asteroid bodies",
      "Langhans giant cell (horseshoe nuclei) vs Foreign body giant cell (random nuclei)",
      "Leprosy: Virchow cells in lepromatous; Granulomas in tuberculoid"]),

    # ── MICROBIOLOGY ──────────────────────────────────────────────────────────
    (14, "MICROBIOLOGY", "Gram Positive vs Gram Negative Bacteria",
     "Gram +ve: thick peptidoglycan, no outer membrane. Gram −ve: thin PG, outer membrane with LPS.",
     "Gram staining differentiates bacteria based on cell wall composition. Gram +ve retain crystal violet (appear purple); Gram −ve decolorize and take safranin (appear red/pink). LPS (endotoxin) in Gram −ve bacteria mediates septic shock via TLR-4.",
     ["Gram +ve cocci: Staph aureus, Strep pyogenes, Strep pneumoniae, Enterococcus",
      "Gram +ve rods: Bacillus, Clostridium, Listeria, Corynebacterium",
      "Gram −ve cocci: Neisseria meningitidis, N. gonorrhoeae",
      "Gram −ve rods: E. coli, Klebsiella, Pseudomonas, Salmonella, Shigella",
      "LPS = Lipid A = endotoxin → fever, hypotension, DIC",
      "SOME bugs are Gram variable or poorly staining: Mycobacteria, Treponema"]),

    (15, "MICROBIOLOGY", "Virulence Factors & Toxins",
     "Cholera toxin: ADP-ribosylates Gs (↑cAMP → rice-water diarrhea). Botulinum: cleaves SNARE.",
     "Bacterial toxins are key NEET PG targets. Exotoxins are proteins (heat-labile, antigenic); endotoxin (LPS) is heat-stable, part of outer membrane.",
     ["Cholera toxin: Gs stimulation → ↑cAMP → Cl- secretion → watery diarrhea",
      "E. coli LT toxin: similar mechanism to cholera",
      "Pertussis toxin: Gi inhibition → ↑cAMP → lymphocytosis",
      "Anthrax toxin: Edema factor (adenylate cyclase) + Lethal factor (protease)",
      "Botulinum toxin: blocks ACh release at NMJ → flaccid paralysis",
      "Tetanus toxin (Tetanospasmin): blocks GABA/glycine at inhibitory interneurons → spastic paralysis",
      "Diphtheria toxin: ADP-ribosylates EF-2 → halts protein synthesis → myocarditis"]),

    (16, "MICROBIOLOGY", "TORCH Infections in Pregnancy",
     "TORCH: Toxoplasma, Other, Rubella, CMV, Herpes/HIV – cause congenital infections.",
     "TORCH infections cross the placenta or infect during delivery. CMV is the most common congenital viral infection. Rubella in first trimester causes the classic triad. Toxoplasma: cat litter. Herpes: neonatal infection during vaginal delivery.",
     ["Toxoplasma: Chorioretinitis, hydrocephalus, intracranial calcifications (periventricular)",
      "Rubella (1st trimester): Cataracts, PDA, sensorineural deafness (classic triad)",
      "CMV: Most common; periventricular calcifications, 'blueberry muffin rash', SNHL",
      "Herpes HSV-2: Neonatal encephalitis, skin/eye/mouth lesions",
      "Syphilis (Treponema): Saddle nose, sabre tibia, Hutchinson teeth, interstitial keratitis",
      "HIV: Mother-to-child transmission; Zidovudine reduces transmission"]),

    # ── PHARMACOLOGY ──────────────────────────────────────────────────────────
    (17, "PHARMACOLOGY", "Beta-Blocker Pharmacology",
     "Beta-blockers: negative inotropy/chronotropy; 1st line in HF (bisoprolol), post-MI, HTN.",
     "Beta-adrenergic blockers competitively block beta-1 (heart) and/or beta-2 (lung, peripheral vessels) receptors. Cardioselective agents (beta-1 selective) preferred in asthmatics, diabetics (mask hypoglycemia symptoms except sweating).",
     ["Cardioselective (beta-1): Metoprolol, Bisoprolol, Atenolol (MBA)",
      "Non-selective: Propranolol (also used for thyrotoxicosis, essential tremor, migraine prophylaxis)",
      "With ISA: Pindolol (partial agonist – less bradycardia at rest)",
      "Alpha+Beta: Carvedilol, Labetalol (used in hypertensive emergencies, pregnancy)",
      "Contraindications: Asthma, AV block, cardiogenic shock",
      "Abrupt withdrawal: rebound hypertension, angina, arrhythmia"]),

    (18, "PHARMACOLOGY", "Antibiotic Mechanisms & Resistance",
     "Penicillin: inhibits transpeptidase; Aminoglycosides: 30S; Fluoroquinolones: DNA gyrase.",
     "Antibiotics are categorized by their target. Resistance mechanisms: beta-lactamase production, efflux pumps, target modification, reduced permeability.",
     ["Cell wall synthesis: Beta-lactams (penicillin, cephalosporins, carbapenems), Vancomycin (binds D-Ala-D-Ala)",
      "30S ribosome: Aminoglycosides (irreversible), Tetracyclines (reversible)",
      "50S ribosome: Chloramphenicol, Macrolides (erythromycin), Linezolid, Clindamycin",
      "DNA gyrase/topoisomerase IV: Fluoroquinolones (ciprofloxacin)",
      "RNA polymerase: Rifampicin",
      "Folate synthesis: Sulfonamides (DHPS), Trimethoprim (DHFR)",
      "Cell membrane: Polymyxin B, Daptomycin (Gram +ve)"]),

    (19, "PHARMACOLOGY", "Drug-Induced Side Effects (High Yield)",
     "Aminoglycosides: ototoxicity + nephrotoxicity. Chloroquine: retinopathy. Rifampicin: orange urine.",
     "Specific drug toxicities are classic MCQ fodder. Always link drug → unique side effect → mechanism.",
     ["Statins: Myopathy/rhabdomyolysis (↑ CK); Hepatotoxicity",
      "Metformin: Lactic acidosis (contraindicated in renal failure/contrast)",
      "Cisplatin: Nephrotoxicity, ototoxicity, peripheral neuropathy",
      "Amiodarone: Pulmonary fibrosis, thyroid dysfunction, corneal deposits, photosensitivity",
      "Isoniazid: Peripheral neuropathy (Vit B6 depletion), hepatitis, SLE-like",
      "Clozapine: Agranulocytosis (monitor CBC weekly)",
      "Lithium: Tremor, polyuria (nephrogenic DI), hypothyroidism",
      "Tetracyclines: Teeth discoloration, photosensitivity (avoid <8 yr, pregnancy)"]),

    # ── MEDICINE ──────────────────────────────────────────────────────────────
    (20, "MEDICINE", "Myocardial Infarction – Diagnosis & Management",
     "STEMI: ST elevation + troponin rise; primary PCI within 90 min is gold standard.",
     "Acute MI results from plaque rupture and coronary artery thrombosis. Irreversible injury begins after 20–40 min ischemia. Biomarkers: Troponin I/T (most sensitive and specific), CK-MB (early re-infarction marker), Myoglobin (earliest, least specific).",
     ["STEMI: ST elevation ≥1 mm in ≥2 contiguous leads; LBBB pattern",
      "NSTEMI: Troponin +ve without ST elevation",
      "Unstable angina: no troponin rise, ischemia at rest/minimal exertion",
      "Complication timeline: Arrhythmia (1st day) > Pericarditis (days 2-4) > Dressler syndrome (weeks)",
      "Papillary muscle rupture (day 3-5): new MR murmur, acute pulmonary edema",
      "Acute management: MONA – Morphine, O2 (if SpO2 <90%), Nitrates, Aspirin (loading 300 mg) + Clopidogrel/Ticagrelor",
      "Long-term: ACEi, Beta-blocker, Statin, Aspirin, Clopidogrel"]),

    (21, "MEDICINE", "Heart Failure Classification & Management",
     "HFrEF (EF <40%): ACEi + Beta-blocker + spironolactone reduce mortality.",
     "Heart failure is inability to maintain adequate cardiac output. Systolic (HFrEF) vs Diastolic (HFpEF). NYHA classification grades functional capacity. BNP/NT-proBNP is the diagnostic biomarker of choice.",
     ["HFrEF drugs with mortality benefit: ACEi/ARB, Beta-blockers (bisoprolol/carvedilol), MRA (spironolactone), ARNI (sacubitril/valsartan), SGLT2i (dapagliflozin)",
      "Acute pulmonary edema: Furosemide + GTN + sit upright + O2",
      "NYHA I: No symptoms; II: Symptoms with moderate exertion; III: Symptoms with minimal exertion; IV: Symptoms at rest",
      "BNP >100 pg/mL supports HF diagnosis",
      "CXR: Bat-wing pulmonary edema, cardiomegaly, Kerley B lines, pleural effusion"]),

    (22, "MEDICINE", "Diabetes Mellitus – Diagnosis & Management",
     "Diagnosis: Fasting glucose ≥126 mg/dL, or 2hr OGTT ≥200, or HbA1c ≥6.5%.",
     "Type 1 DM: absolute insulin deficiency, autoimmune (anti-GAD, anti-IA2, anti-insulin Ab). Type 2: insulin resistance + progressive beta-cell failure. HbA1c reflects average glucose over 2-3 months.",
     ["Metformin: 1st line T2DM; inhibits hepatic gluconeogenesis; CI: eGFR <30",
      "SGLT2 inhibitors (gliflozins): ↓ cardiovascular mortality in HF + T2DM",
      "GLP-1 agonists (liraglutide): weight loss + CV benefit",
      "DKA: T1DM; pH <7.3, ketones +, glucose >250; Tx: fluids + insulin + K+",
      "HHS: T2DM; hyperosmolar, minimal ketosis, very high glucose (>600), high mortality",
      "Hypoglycemia: Whipple's triad – symptoms + low BG + relief with glucose",
      "Target HbA1c: <7% (ADA), <53 mmol/mol (NICE)"]),

    (23, "MEDICINE", "Hypertension Classification & Management",
     "HTN: BP ≥140/90 mmHg on two occasions; Stage 2: ≥160/100; Hypertensive emergency: end-organ damage.",
     "Essential hypertension (95%): no identifiable cause. Secondary causes: CKD (most common secondary cause), primary aldosteronism, renal artery stenosis, phaeochromocytoma, Cushing's.",
     ["1st line for most: ACEi/ARB (especially in DM + CKD), CCB (amlodipine), thiazide",
      "CCBs preferred in elderly, Afro-Caribbean patients",
      "ACEi: C/I in pregnancy → bilateral RAS → dry cough (switch to ARB)",
      "Hypertensive urgency (no organ damage): oral labetalol/amlodipine",
      "Hypertensive emergency: IV labetalol/nitroprusside; reduce MAP by 25% in first hour",
      "Malignant hypertension: >180/120 + papilloedema/retinal haemorrhages"]),

    (24, "MEDICINE", "Thyroid Disorders",
     "Hypothyroidism: TSH ↑, T4 ↓; Hyperthyroidism: TSH ↓, T4 ↑. TSH is the best screening test.",
     "The hypothalamic-pituitary-thyroid axis regulates thyroid hormone production. TRH → TSH → T3/T4. T4 is prohormone; T3 is active form. Negative feedback at pituitary.",
     ["Hypothyroidism Sx: cold intolerance, constipation, weight gain, bradycardia, non-pitting edema (myxedema), delayed DTRs",
      "Hashimoto's thyroiditis: most common cause hypothyroidism; anti-TPO Ab, anti-Tg Ab",
      "Hyperthyroidism Sx: heat intolerance, diarrhea, weight loss, palpitations, tremor, exophthalmos (Graves)",
      "Graves disease: TSH receptor Ab (TSI); autoimmune; pretibial myxedema",
      "Treatment Graves: Carbimazole/PTU, Radioiodine, Surgery",
      "Thyroid storm: Propranolol + PTU + iodine (Lugol's) + hydrocortisone",
      "Sick euthyroid syndrome: ↓ T3, normal/↓ T4, normal/↓ TSH – seen in critically ill"]),

    # ── SURGERY ───────────────────────────────────────────────────────────────
    (25, "SURGERY", "Surgical Causes of Acute Abdomen",
     "Guarding + rigidity = peritonitis; Shifting dullness + absent bowel sounds = obstruction.",
     "Acute abdomen requires rapid diagnosis. Murphy's sign (cholecystitis), Rovsing's sign (appendicitis), Cullen's sign (umbilical bruising – haemoperitoneum), Grey-Turner sign (flank bruising – retroperitoneal hemorrhage).",
     ["Appendicitis: McBurney's point tenderness, Psoas sign, Obturator sign; WBC ↑",
      "Acute pancreatitis: epigastric pain radiating to back, Serum amylase/lipase >3× normal",
      "Cholecystitis: Murphy's sign +, fever, RUQ pain after fatty meal, USS gold standard",
      "Peptic ulcer perforation: sudden-onset severe epigastric pain, 'free air' under diaphragm on erect CXR",
      "Mesenteric ischemia: pain out of proportion to exam, atrial fibrillation risk factor",
      "Intestinal obstruction: colicky pain, vomiting, distension, constipation; central dilated loops (small bowel) vs peripheral (large bowel) on AXR"]),

    (26, "SURGERY", "Fluid & Electrolyte Management",
     "Hartmann's (Ringer's lactate) is the resuscitation fluid of choice in surgery/trauma.",
     "IV fluids replace lost volume and correct electrolyte imbalances. Crystalloids vs colloids. 0.9% NaCl can cause hyperchloraemic acidosis if large volumes given. Dextrose distributes into intracellular compartment.",
     ["Normal saline (0.9%): 154 mEq/L Na and Cl; hyperchloraemic acidosis with large volumes",
      "Hartmann's: Na 131, K 5, Ca 2, Cl 111, lactate 29 mEq/L – most physiological",
      "5% Dextrose: distributes to all body water (TBW); not for volume resuscitation",
      "Daily requirements: Na 1 mmol/kg, K 1 mmol/kg, fluid 30 mL/kg/day",
      "Hyponatraemia: correct slowly (<10-12 mEq/L per 24h) to prevent central pontine myelinolysis",
      "Hyperkalaemia >6.5 mEq/L with ECG changes: IV calcium gluconate (membrane stabilisation) first"]),

    # ── OBSTETRICS & GYNAECOLOGY ──────────────────────────────────────────────
    (27, "OBG", "Pre-eclampsia & Eclampsia",
     "Pre-eclampsia: BP ≥140/90 + proteinuria after 20 weeks. Only cure is delivery.",
     "Pre-eclampsia results from abnormal placentation and maternal endothelial dysfunction. HELLP syndrome (Haemolysis, Elevated Liver enzymes, Low Platelets) is a severe complication. Risk factors: nulliparity, multiple pregnancy, CKD, prior PE.",
     ["Diagnosis: BP ≥140/90 on 2 occasions 4h apart + proteinuria ≥300 mg/24h after 20 wk",
      "Severe PE: BP ≥160/110, severe headache, visual disturbances, epigastric pain, oliguria",
      "HELLP: haemolysis (↑LDH, ↑bilirubin, schistocytes), AST/ALT ↑, platelets <100,000",
      "Eclampsia: seizures in setting of pre-eclampsia; Tx: IV MgSO4 (anticonvulsant of choice)",
      "MgSO4 toxicity: loss of DTRs (first sign, at ~7 mEq/L), respiratory depression (>12 mEq/L); antidote: IV calcium gluconate",
      "Antihypertensives safe in pregnancy: Labetalol, Hydralazine, Nifedipine, Methyldopa"]),

    (28, "OBG", "Normal Labour & Stages",
     "Stage 1: effacement/dilation (latent <6cm, active >6cm); Stage 2: delivery; Stage 3: placenta.",
     "Labour is defined as regular uterine contractions with progressive cervical effacement and dilation. Active management reduces PPH. CTG monitoring helps detect fetal distress.",
     ["Latent phase: 0–6 cm; Active phase: 6–10 cm (rate ≥1 cm/hr expected)",
      "Stage 2: full dilation to delivery of baby; ≤2 hr nullipara, ≤1 hr multipara",
      "Stage 3: delivery of placenta; active management with oxytocin reduces PPH",
      "PPH: blood loss >500 mL (vaginal) or >1000 mL (caesarean); 4 Ts – Tone (most common), Trauma, Tissue, Thrombin",
      "CTG: Normal FHR 110–160 bpm; decelerations – Early (head compression), Variable (cord compression), Late (placental insufficiency)"]),

    (29, "OBG", "Gynaecological Cancers – Key Features",
     "Endometrial cancer: most common; postmenopausal bleeding. Cervical: HPV 16/18; Pap smear screen.",
     "Gynaecological malignancies differ in risk factors, screening, and treatment. Know the classic presentation for each.",
     ["Cervical cancer: HPV 16/18 (squamous cell – 80%); Pap smear/colposcopy; LEEP/cone biopsy",
      "Endometrial cancer: unopposed oestrogen (obesity, PCOS, tamoxifen), Lynch syndrome; D&C/hysteroscopy biopsy; Tx: hysterectomy + BSO",
      "Ovarian cancer: 'silent killer' – CA-125 + pelvic USS; BRCA1/2 mutation risk; serous cystadenocarcinoma most common",
      "Vulvar cancer: SCC, postmenopausal, pruritus, white plaque (lichen sclerosus)",
      "CIN grading: CIN 1 (mild dysplasia) → CIN 3 (carcinoma in situ)"]),

    # ── PAEDIATRICS ───────────────────────────────────────────────────────────
    (30, "PAEDIATRICS", "Developmental Milestones",
     "Smile: 6 wk; Sit unsupported: 6 mo; Walk: 12–15 mo; 2-word phrases: 24 mo.",
     "Developmental assessment covers gross motor, fine motor, speech/language, and social domains. Regression of milestones is always abnormal. Delays prompt investigation for metabolic/structural causes.",
     ["3 months: holds head up, social smile (6 weeks), follows past midline",
      "6 months: rolls over, sits with support, babbles",
      "9 months: sits unsupported, pincer grasp emerging, stranger anxiety",
      "12 months: walks with support/alone, 1-2 words with meaning, waves bye-bye",
      "18 months: walks well, 10+ words, points to body parts",
      "24 months: runs, 2-word phrases, 50+ words; parallel play",
      "Red flags: no social smile by 3 mo, no babble by 12 mo, no words by 16 mo, any regression"]),

    (31, "PAEDIATRICS", "Childhood Vaccination Schedule (India – UIP)",
     "BCG: birth; OPV+Penta: 6,10,14 wk; Measles: 9 mo; MMR: 15 mo; DPT booster: 18 mo.",
     "India's Universal Immunisation Programme (UIP) protects against 12 diseases. Key vaccine facts for MCQs: cold chain, contraindications, schedules.",
     ["BCG: Birth; prevents miliary TB and TB meningitis; scar appears at 6-8 weeks",
      "OPV (oral polio): 0, 6, 10, 14 wk + boosters; VAPP risk (use IPV if immunocompromised)",
      "Pentavalent (DPT+HepB+Hib): 6, 10, 14 weeks",
      "Measles: 9-12 months; MMR: 15-18 months (2nd dose at 5 years)",
      "JE vaccine: 9-12 months in endemic areas",
      "Typhoid (Vi capsular): 2 years+; Rotavirus: 6, 10, 14 weeks (oral)",
      "Hepatitis B: 3 doses at 0, 1, 6 months OR birth dose + 6, 10, 14 weeks"]),

    # ── PSYCHIATRY ────────────────────────────────────────────────────────────
    (32, "PSYCHIATRY", "Schizophrenia – Diagnosis & Treatment",
     "Schizophrenia: ≥2 positive symptoms for ≥1 month; prodrome >6 months; dopamine excess theory.",
     "Schizophrenia is characterised by positive symptoms (hallucinations, delusions, disorganized thinking) and negative symptoms (flat affect, alogia, avolition). Dopamine D2 receptor hyperactivity in mesolimbic pathway mediates positive symptoms.",
     ["Schneider's 1st rank symptoms: Thought insertion/withdrawal/broadcasting, Passivity phenomena, Somatic hallucinations, Delusional perception, Running commentary",
      "Typical antipsychotics: Haloperidol, Chlorpromazine – block D2; SE: EPS, tardive dyskinesia, hyperprolactinaemia",
      "Atypical antipsychotics: Olanzapine, Risperidone, Clozapine – D2 + 5HT2A; fewer EPS",
      "Clozapine: reserved for treatment-resistant schizophrenia; risk agranulocytosis",
      "Neuroleptic Malignant Syndrome: Hyperthermia, Rigidity, Altered consciousness, ↑CK; Tx: Bromocriptine + Dantrolene",
      "Negative symptoms: 5 As – Affective flattening, Alogia, Avolition, Anhedonia, Attention deficits"]),

    (33, "PSYCHIATRY", "Depression & Antidepressants",
     "Depression: ≥5 symptoms ≥2 weeks including low mood/anhedonia. SSRIs are 1st line.",
     "Major depressive disorder (MDD) is defined by depressed mood or anhedonia plus additional symptoms for at least 2 weeks. Biological theory: monoamine deficiency (serotonin, noradrenaline, dopamine).",
     ["Core symptoms: Low mood + anhedonia (at least one required)",
      "Others: Sleep disturbance, Appetite change, Concentration difficulties, Energy loss, Guilt/worthlessness, Psychomotor changes, Suicidal ideation",
      "SSRIs (1st line): Fluoxetine, Sertraline, Escitalopram – SE: sexual dysfunction, serotonin syndrome",
      "SNRIs: Venlafaxine, Duloxetine – also used for pain, anxiety",
      "TCAs: Amitriptyline – SE: anticholinergic (dry mouth, urinary retention, constipation), arrhythmias",
      "MAOIs: Phenelzine – tyramine interaction → hypertensive crisis (avoid aged cheese)",
      "Electroconvulsive therapy (ECT): 1st line in severe depression with psychotic features, suicidal risk, or failure of pharmacotherapy"]),

    # ── ENT ───────────────────────────────────────────────────────────────────
    (34, "ENT", "Otitis Media – Acute & Chronic",
     "AOM: fever + otalgia; bulging red TM; Strep pneumoniae most common causative organism.",
     "Otitis media is inflammation of the middle ear. Acute (AOM) vs chronic suppurative (CSOM) vs otitis media with effusion (glue ear). Eustachian tube dysfunction is central to pathogenesis.",
     ["AOM causative organisms: S. pneumoniae (most common), H. influenzae, M. catarrhalis",
      "AOM treatment: Amoxicillin (amoxicillin-clavulanate if treatment failure)",
      "Complications of AOM: Mastoiditis, Meningitis, Lateral sinus thrombosis, Facial nerve palsy",
      "CSOM: chronic discharge >6 wk; mucosal type vs squamous (cholesteatoma)",
      "Cholesteatoma: keratinous debris trapped in middle ear; attic perforation on otoscopy; Tx: surgery",
      "Glue ear (OME): conductive hearing loss in children; myringotomy + grommets if persistent"]),

    (35, "ENT", "Hoarseness – Differential Diagnosis",
     "Hoarseness >3 weeks requires laryngoscopy to exclude laryngeal carcinoma.",
     "Hoarseness (dysphonia) results from any disorder of the larynx or recurrent laryngeal nerve. Red flag: unilateral, progressive, associated weight loss → malignancy until proven otherwise.",
     ["Benign: Vocal cord nodules (screamer's nodule), Polyps, Laryngitis, GERD",
      "Functional: Psychogenic dysphonia, Muscle tension dysphonia",
      "Malignant: Laryngeal SCC – most common in hypopharynx/glottis; smoking + alcohol risk",
      "Neurological: RLN palsy (thyroid surgery, aortic aneurysm, lung cancer – left side)",
      "Left RLN: longer course, loops around arch of aorta; more commonly injured",
      "Investigation: Flexible laryngoscopy; CT neck/chest; Biopsy for malignancy"]),

    # ── OPHTHALMOLOGY ─────────────────────────────────────────────────────────
    (36, "OPHTHALMOLOGY", "Glaucoma – Types & Management",
     "Primary open-angle glaucoma: painless, gradual visual field loss; IOP >21 mmHg.",
     "Glaucoma is a group of conditions characterised by optic nerve damage, visual field loss, and elevated IOP. Primary open-angle (chronic) is the most common. Primary angle-closure (acute) is an emergency.",
     ["POAG: Insidious visual loss; open drainage angle; cupping of optic disc (C:D ratio >0.6)",
      "Acute angle closure: Red eye, severe pain, haloes, nausea, rock-hard eye, mid-dilated pupil",
      "IOP normal: 10–21 mmHg; Normal tension glaucoma: disc damage with normal IOP",
      "1st line treatment: Topical prostaglandin analogue (latanoprost) → ↑ uveoscleral outflow",
      "Beta-blockers (timolol): ↓ aqueous production; C/I asthma",
      "Carbonic anhydrase inhibitors (acetazolamide): ↓ aqueous production – used in acute crisis",
      "Laser trabeculoplasty/trabeculectomy for refractory cases"]),

    (37, "OPHTHALMOLOGY", "Diabetic Retinopathy",
     "NPDR: microaneurysms → hard exudates → cotton wool spots. PDR: neovascularisation.",
     "Diabetic retinopathy is the leading cause of blindness in working-age adults. Annual fundoscopy/retinal photography is mandatory in all diabetics. Duration of diabetes is the strongest risk factor.",
     ["Background/Mild NPDR: Microaneurysms only",
      "Moderate/Severe NPDR: Dot-blot hemorrhages, hard exudates, cotton-wool spots",
      "Proliferative DR (PDR): New vessel formation (NVD/NVE), vitreous hemorrhage, tractional retinal detachment",
      "Clinically significant macular edema (CSME): Treat with intravitreal anti-VEGF (bevacizumab/ranibizumab)",
      "Panretinal photocoagulation (PRP): treatment for PDR",
      "Screening: Annual dilated fundoscopy from diagnosis (T2DM) or 5 years after diagnosis (T1DM)"]),

    # ── DERMATOLOGY ───────────────────────────────────────────────────────────
    (38, "DERMATOLOGY", "Skin Lesion Terminology",
     "Macule: flat <1cm; Papule: raised <1cm; Plaque: raised >1cm; Vesicle: blister <0.5cm; Bulla: blister >0.5cm.",
     "Precise skin lesion description is fundamental to dermatology diagnosis. Primary lesions arise from normal skin; secondary lesions result from evolution or manipulation of primary lesions.",
     ["Primary: Macule, Papule, Plaque, Nodule, Vesicle, Bulla, Pustule, Wheal (urticaria), Cyst",
      "Secondary: Scale, Crust, Erosion (superficial), Ulcer (deep), Lichenification, Scar, Excoriation",
      "Koebner phenomenon: lesions appear in areas of skin trauma (psoriasis, lichen planus, vitiligo, warts)",
      "Auspitz sign: bleeding on removal of psoriatic scale (pinpoint capillary bleeding)",
      "Nikolsky sign: blister extends/creates new blister on lateral pressure (pemphigus vulgaris, SSSS)"]),

    (39, "DERMATOLOGY", "Common Skin Conditions – High-Yield Differentials",
     "Psoriasis: silver scaly plaques on extensor surfaces. Lichen planus: 4Ps – Purple, Pruritic, Polygonal, Papules.",
     "Inflammatory skin diseases are distinguished by morphology, distribution, histology, and associated conditions.",
     ["Psoriasis: Well-demarcated silver scaly plaques; elbows, knees, scalp; nail pitting; HLA-Cw6",
      "Lichen planus: Wickham's striae (white lacy pattern), buccal mucosa involvement; HLA-DR1",
      "Atopic eczema: flexural distribution; IgE mediated; associated with asthma, allergic rhinitis",
      "Pemphigus vulgaris: flaccid blisters, Nikolsky+, oral involvement; IgG vs desmoglein 3",
      "Bullous pemphigoid: tense blisters, Nikolsky−, elderly; IgG vs BP180 (BPAG2) in basement membrane",
      "Dermatitis herpetiformis: intensely pruritic vesicles on extensor surfaces; coeliac disease; IgA deposits"]),

    # ── ORTHOPAEDICS ──────────────────────────────────────────────────────────
    (40, "ORTHOPAEDICS", "Fracture Complications",
     "Fat embolism: 24-72hr post long bone #; Compartment syndrome: 6Ps; DVT: most common late complication.",
     "Complications of fractures can be immediate, early, or late. Compartment syndrome is a surgical emergency requiring fasciotomy within hours to prevent permanent nerve/muscle damage.",
     ["Fat embolism syndrome: hypoxia, petechiae (upper body), confusion – 24-72 hr post femur/tibia #",
      "Compartment syndrome: 6 Ps – Pain (especially with passive stretch), Pressure (tense compartment), Paresthesia, Paralysis, Pallor, Pulselessness; Tx: emergency fasciotomy",
      "AVN (avascular necrosis): after neck of femur fracture, scaphoid waist fracture, dislocation of hip; MRI is most sensitive investigation",
      "Malunion: healed in incorrect position; Non-union: failure to heal by 6 months",
      "DVT/PE: most common late complication; prophylaxis with LMWH, compression stockings",
      "Reflex Sympathetic Dystrophy (CRPS): burning pain, allodynia, autonomic changes"]),

    (41, "ORTHOPAEDICS", "Common Orthopaedic Tests",
     "Lachman's test: ACL integrity; McMurray's: meniscus; Apprehension test: shoulder dislocation.",
     "Clinical examination tests help localise musculoskeletal pathology. NEET PG tests name, technique, and interpretation.",
     ["Lachman's test: ACL tear – most sensitive (>85%)",
      "Anterior/Posterior drawer test: ACL/PCL tear",
      "McMurray's test: meniscal tear – pain/click on rotation",
      "Valgus/varus stress test: MCL/LCL integrity",
      "Apprehension test: anterior shoulder instability (recurrent dislocation)",
      "Trendelenburg test: hip abductor weakness / superior gluteal nerve palsy",
      "FABER (Patrick's test): hip pathology / sacroiliac joint disease",
      "Thomas test: hip flexion contracture"]),

    # ── FORENSIC MEDICINE ─────────────────────────────────────────────────────
    (42, "FORENSIC MEDICINE", "Thanatology – Signs of Death",
     "Brain death: fixed dilated pupils + no brainstem reflexes + apnea + flat EEG.",
     "Thanatology is the study of death. Signs of death progress from immediate (cardiac/respiratory arrest) to early (pallor, cooling) to late (rigor mortis, putrefaction).",
     ["Rigor mortis: starts 2-6 hr, complete at 12 hr, disappears at 36-48 hr (higher temp shortens)",
      "Livor mortis (hypostasis): appears 1-2 hr, fixes at 6-8 hr; pink-red in CO poisoning; cherry red in cyanide",
      "Algor mortis: body cools ~1°C/hr for first 12 hr in average conditions",
      "Putrefaction: starts 24-48 hr in abdomen (bacteria); marbling, green discolouration",
      "Adipocere: saponification of body fat; wet/waterlogged conditions; 3-6 months",
      "Mummification: dry heat/arid conditions; body desiccates preserving features"]),

    (43, "FORENSIC MEDICINE", "Wounds – Classification & Medico-legal Importance",
     "Incised wound: sharp cutting force, clean edges. Laceration: blunt force, irregular edges with tissue bridging.",
     "Wound classification is critical in forensic assessment of cause of death, weapon identification, and establishing manner of death.",
     ["Incised wound: clean-cut edges, no bruising at margins, greater length than depth",
      "Stab wound: greater depth than length; entry wound characteristic of weapon",
      "Laceration: blunt force; irregular, contaminated edges; tissue bridges at base",
      "Contusion (bruise): extravasation of blood; does not blanch on pressure",
      "Abrasion: superficial; marks direction of force (tramline abrasion = blunt rod)",
      "Gunshot wound: entry (inverted, abraded collar, small) vs exit (larger, irregular, no abrasion collar)",
      "Hesitation marks: tentative cuts in cases of self-inflicted wounds"]),

    # ── COMMUNITY MEDICINE / PSM ──────────────────────────────────────────────
    (44, "COMMUNITY MEDICINE", "Epidemiology – Key Measures",
     "Incidence = new cases/population at risk per unit time. Prevalence = existing cases/total population.",
     "Epidemiological measures quantify disease burden and risk. Correct interpretation of study designs and statistical measures is heavily tested.",
     ["Incidence rate: new cases per 1000/100,000 at-risk people per year",
      "Prevalence = Incidence × Duration of disease",
      "Attack rate: incidence proportion in an outbreak (epidemic)",
      "Relative Risk (RR): risk in exposed/risk in unexposed – used in cohort studies",
      "Odds Ratio (OR): odds in cases/odds in controls – used in case-control studies; approximates RR when prevalence is low",
      "Attributable Risk (AR) = Risk(exposed) − Risk(unexposed) – public health impact",
      "Number Needed to Treat (NNT) = 1/Absolute Risk Reduction"]),

    (45, "COMMUNITY MEDICINE", "Screening Tests – Sensitivity & Specificity",
     "Sensitive test: fewer false negatives (good to RULE OUT). Specific test: fewer false positives (good to RULE IN).",
     "Sensitivity and specificity are intrinsic properties of a test; PPV and NPV depend on disease prevalence.",
     ["Sensitivity = TP/(TP+FN) = True Positive Rate; 'SnNout' – sensitive test negative rules OUT",
      "Specificity = TN/(TN+FP) = True Negative Rate; 'SpPin' – specific test positive rules IN",
      "PPV = TP/(TP+FP) – increases with higher prevalence",
      "NPV = TN/(TN+FN) – decreases with higher prevalence",
      "ROC curve: plots sensitivity vs (1-specificity); area under curve = test discrimination",
      "Likelihood ratio positive = Sensitivity/(1-Specificity)",
      "Ideal screening test: High sensitivity (to catch all cases), affordable, acceptable"]),

    # ── RADIOLOGY ─────────────────────────────────────────────────────────────
    (46, "RADIOLOGY", "X-Ray Interpretation – Key Patterns",
     "Consolidation: air bronchograms; Collapse: dense with volume loss; Pleural effusion: meniscus sign.",
     "Plain X-ray remains the first-line investigation in many clinical scenarios. Systematic interpretation (ABCDE) prevents missed findings.",
     ["Air bronchogram: patent bronchi within consolidated lung – suggests pneumonia, not effusion",
      "Silhouette sign: loss of normal heart/diaphragm border when adjacent structure is consolidated",
      "CXR cardiac enlargement: cardiothoracic ratio >50% on PA film",
      "Bat-wing/butterfly pattern: bilateral perihilar air-space opacification – pulmonary edema",
      "Reticular nodular pattern: interstitial lung disease (sarcoid, IPF, hypersensitivity pneumonitis)",
      "Pleural effusion: blunting of costophrenic angle; meniscus sign; >200 mL visible on PA CXR",
      "Pneumothorax: absent lung markings with visible visceral pleural line"]),

    (47, "RADIOLOGY", "MRI vs CT – Clinical Decision Making",
     "MRI: best for soft tissue, CNS, spine. CT: best for bone, trauma, chest, abdomen emergencies.",
     "Choosing the right imaging modality improves diagnostic yield and reduces radiation exposure. MRI uses magnetic fields and radiofrequency waves; no ionising radiation.",
     ["MRI T1: fat bright, water dark; good for anatomy",
      "MRI T2: water bright (CSF, edema); best for detecting pathology",
      "CT: fast (minutes), best for hemorrhage (bright on CT), fractures, thoracic/abdominal pathology",
      "CT with contrast: vascular lesions, abscess, malignancy, liver lesions",
      "MRI C-spine: disc prolapse, cord compression preferred over CT",
      "Non-contrast CT head: first investigation for suspected acute stroke (to exclude hemorrhage)",
      "PET-CT: metabolic activity; tumour staging, recurrence detection"]),

    # ── ANAESTHESIA ───────────────────────────────────────────────────────────
    (48, "ANAESTHESIA", "Anaesthetic Agents – Mechanism & Side Effects",
     "Propofol: rapid induction/recovery; Ketamine: dissociative analgesia; Thiopental: ultra-short barbiturate.",
     "Intravenous induction agents work rapidly due to high lipid solubility and CNS penetration. All cause cardiovascular depression to varying degrees.",
     ["Propofol: GABA-A potentiation; 'propofol infusion syndrome' – metabolic acidosis, cardiac failure",
      "Ketamine: NMDA receptor antagonist; dissociative anesthesia; preserves airway reflexes; bronchodilator; contraindicated in ↑ICP/IOP",
      "Thiopental: barbiturate; GABA potentiation; decreases ICP; porphyria contraindication",
      "Etomidate: adrenocortical suppression; least cardiovascular depression (good for shocked patients)",
      "Volatile agents: Halothane – hepatotoxicity; Isoflurane – hypotension; Sevoflurane – paediatric induction",
      "Suxamethonium: depolarising muscle relaxant; contraindicated in burns/crush injury (hyperkalemia), malignant hyperthermia"]),

    (49, "ANAESTHESIA", "Malignant Hyperthermia",
     "Malignant hyperthermia: uncontrolled skeletal muscle metabolism triggered by suxamethonium/volatile agents; Rx: Dantrolene.",
     "MH is a rare but life-threatening pharmacogenetic disorder of skeletal muscle. The ryanodine receptor (RYR1) mutation causes uncontrolled Ca2+ release from the sarcoplasmic reticulum.",
     ["Triggers: Suxamethonium (most common), halogenated volatile agents (halothane, sevoflurane)",
      "Features: Hyperthermia (>38.5°C, rising), muscle rigidity, masseter spasm, tachycardia, hypercarbia, metabolic acidosis, ↑↑ CK",
      "Lab: Hyperkalaemia, myoglobinuria (rhabdomyolysis), DIC",
      "Treatment: STOP trigger, Dantrolene sodium (2.5 mg/kg IV, repeat), active cooling, supportive care",
      "Dantrolene mechanism: inhibits ryanodine receptor → prevents sarcoplasmic Ca2+ release",
      "Similar condition: Neuroleptic malignant syndrome (antipsychotic triggered; treat with bromocriptine + dantrolene)"]),

    # ── MISCELLANEOUS HIGH-YIELD ───────────────────────────────────────────────
    (50, "HIGH-YIELD MISCELLANEOUS", "Vitamins – Deficiencies & Toxicities",
     "Vit A: night blindness, Bitot's spots. Vit C: scurvy. Vit D: rickets. B12: megaloblastic anemia + subacute combined degeneration.",
     "Vitamin deficiencies are classic NEET PG topics. Fat-soluble vitamins (A, D, E, K) are stored and can accumulate to toxic levels; water-soluble vitamins are generally not toxic except Vit B6 (peripheral neuropathy).",
     ["Vit A: night blindness, xerophthalmia, Bitot's spots; Toxicity: pseudotumor cerebri, teratogenic",
      "Vit B1 (Thiamine): Wernicke's encephalopathy (triad: ophthalmoplegia, ataxia, confusion) + Korsakoff syndrome; Beriberi",
      "Vit B3 (Niacin): Pellagra – 4Ds: Diarrhea, Dermatitis, Dementia, Death",
      "Vit B12: Megaloblastic anemia + Subacute combined degeneration of spinal cord (posterior + lateral columns); anti-IF antibody (pernicious anemia)",
      "Vit C: Scurvy – perifollicular hemorrhages, corkscrew hairs, poor wound healing",
      "Vit D: Rickets (children), Osteomalacia (adults); Toxicity: Hypercalcemia, nephrocalcinosis",
      "Vit K: Bleeding tendency; Newborns lack intestinal flora → hemorrhagic disease of newborn; warfarin antidote"]),
]

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    ("GRID",     (0,0), (-1,-1), 0.3, HexColor("#BDBDBD")),
    ("ROWBACKGROUNDS", (0,0), (-1,-1), [C_WHITE, C_GREY_BG]),
    ("TOPPADDING",    (0,0), (-1,-1), 4),
    ("BOTTOMPADDING", (0,0), (-1,-1), 4),
    ("LEFTPADDING",   (0,0), (-1,-1), 6),
    ("RIGHTPADDING",  (0,0), (-1,-1), 6),
    ("VALIGN",        (0,0), (-1,-1), "MIDDLE"),
]))
story.append(toc_table)
story.append(PageBreak())

# ── Topic Pages ───────────────────────────────────────────────────────────────
last_subject = None

for num, subj, name, one_liner, detail, bullets in TOPICS:
    # Subject separator
    if subj != last_subject:
        if last_subject is not None:
            story.append(Spacer(1, 0.4*cm))
        hdr_color, _ = SUBJECT_COLORS.get(subj, (C_DARK_BLUE, C_LIGHT_BLUE))
        subj_hdr = Table([[Paragraph(f"◆  {subj}", SUBJECT_HEADER)]], colWidths=[W])
        subj_hdr.setStyle(TableStyle([
            ("BACKGROUND", (0,0), (-1,-1), hdr_color),
            ("TOPPADDING",  (0,0),(-1,-1), 7), ("BOTTOMPADDING",(0,0),(-1,-1),7),
            ("LEFTPADDING", (0,0),(-1,-1), 10), ("RIGHTPADDING",(0,0),(-1,-1),10),
            ("BOX", (0,0),(-1,-1), 0.5, hdr_color),
        ]))
        story.append(subj_hdr)
        story.append(Spacer(1, 0.15*cm))
        last_subject = subj

    hdr_color, bg_color = SUBJECT_COLORS.get(subj, (C_DARK_BLUE, C_LIGHT_BLUE))

    # Number badge + topic name row
    num_para = Paragraph(f"<font color='white'><b> {num:02d} </b></font>", TOPIC_NUM)
    num_cell = Table([[num_para]], colWidths=[0.72*cm])
    num_cell.setStyle(TableStyle([
        ("BACKGROUND", (0,0),(-1,-1), hdr_color),
        ("TOPPADDING",  (0,0),(-1,-1), 4), ("BOTTOMPADDING",(0,0),(-1,-1), 4),
        ("LEFTPADDING", (0,0),(-1,-1), 2), ("RIGHTPADDING",(0,0),(-1,-1), 2),
        ("VALIGN", (0,0),(-1,-1), "MIDDLE"),
    ]))

    name_para = Paragraph(f"<font color='{hdr_color.hexval()}'><b>{name}</b></font>",
                          ParagraphStyle("tnn", fontName="Helvetica-Bold", fontSize=13,
                                         alignment=TA_LEFT, leftIndent=6))
    header_row = Table([[num_cell, name_para]], colWidths=[0.9*cm, W-0.9*cm])
    header_row.setStyle(TableStyle([
        ("BACKGROUND", (0,0),(-1,-1), bg_color),
        ("TOPPADDING",  (0,0),(-1,-1), 5), ("BOTTOMPADDING",(0,0),(-1,-1), 5),
        ("LEFTPADDING", (0,0),(-1,-1), 0), ("RIGHTPADDING",(0,0),(-1,-1), 8),
        ("VALIGN", (0,0),(-1,-1), "MIDDLE"),
        ("BOX", (0,0),(-1,-1), 0.5, hdr_color),
    ]))

    # One-liner
    ol_label = Paragraph("⚡ ONE-LINER", ONE_LINER_LABEL)
    ol_text  = Paragraph(one_liner, ONE_LINER_TEXT)

    # Detail
    det_label = Paragraph("📋 EXPLANATION", DETAIL_LABEL)
    det_text  = Paragraph(detail, DETAIL_TEXT)

    # Bullets
    bullet_paras = [Paragraph(f"• {b}", BULLET_STYLE) for b in bullets]

    # Assemble card
    card_content = [header_row, Spacer(1, 0.1*cm),
                    ol_label, ol_text,
                    det_label, det_text] + bullet_paras + [Spacer(1, 0.3*cm)]

    story.append(KeepTogether(card_content))
    story.append(HRFlowable(width=W, thickness=0.3, color=HexColor("#E0E0E0")))
    story.append(Spacer(1, 0.1*cm))

# ── Footer function ────────────────────────────────────────────────────────────
def add_footer(canvas, doc):
    canvas.saveState()
    canvas.setFont("Helvetica", 8)
    canvas.setFillColor(HexColor("#9E9E9E"))
    canvas.drawCentredString(A4[0]/2, 1.2*cm,
        f"NEET PG – Top 50 High-Yield Topics  |  Quick Revision Guide  |  Page {doc.page}")
    canvas.restoreState()

# ── Build ──────────────────────────────────────────────────────────────────────
doc.build(story, onFirstPage=add_footer, onLaterPages=add_footer)
print(f"PDF generated: {OUTPUT}")