#!/usr/bin/env python3
"""
Clinical Biochemistry - Units VI to X
University Exam Notes + Mind Map PDF
"""

from reportlab.lib.pagesizes import A4
from reportlab.lib import colors
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import cm, mm
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle,
    PageBreak, HRFlowable, KeepTogether
)
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY
from reportlab.platypus.flowables import Flowable
import io

# ── colours ──────────────────────────────────────────────────────────────────
BLUE      = colors.HexColor("#1565C0")
DKBLUE    = colors.HexColor("#0D47A1")
LTBLUE    = colors.HexColor("#BBDEFB")
GREEN     = colors.HexColor("#2E7D32")
LTGREEN   = colors.HexColor("#C8E6C9")
ORANGE    = colors.HexColor("#E65100")
LTORANGE  = colors.HexColor("#FFE0B2")
RED       = colors.HexColor("#B71C1C")
LTRED     = colors.HexColor("#FFCDD2")
PURPLE    = colors.HexColor("#4A148C")
LTPURPLE  = colors.HexColor("#E1BEE7")
TEAL      = colors.HexColor("#006064")
LTTEAL    = colors.HexColor("#B2EBF2")
YELLOW    = colors.HexColor("#F9A825")
LTYELLOW  = colors.HexColor("#FFF9C4")
GREY      = colors.HexColor("#37474F")
LTGREY    = colors.HexColor("#ECEFF1")
WHITE     = colors.white
BLACK     = colors.black

# ── styles ────────────────────────────────────────────────────────────────────
base = getSampleStyleSheet()

def mks(name, parent="Normal", **kw):
    return ParagraphStyle(name, parent=base[parent], **kw)

COVER_TITLE  = mks("CoverTitle",  fontSize=28, textColor=WHITE,
                   alignment=TA_CENTER, spaceAfter=8, fontName="Helvetica-Bold")
COVER_SUB    = mks("CoverSub",    fontSize=14, textColor=LTBLUE,
                   alignment=TA_CENTER, spaceAfter=4, fontName="Helvetica")
UNIT_HDR     = mks("UnitHdr",     fontSize=18, textColor=WHITE,
                   alignment=TA_CENTER, spaceAfter=6, fontName="Helvetica-Bold")
SECTION_HDR  = mks("SectionHdr",  fontSize=13, textColor=DKBLUE,
                   spaceBefore=10, spaceAfter=4, fontName="Helvetica-Bold")
SUBSEC_HDR   = mks("SubsecHdr",   fontSize=11, textColor=GREEN,
                   spaceBefore=6, spaceAfter=3, fontName="Helvetica-Bold")
BODY         = mks("Body",        fontSize=10, leading=15, spaceAfter=4,
                   alignment=TA_JUSTIFY)
BULLET       = mks("Bullet",      fontSize=10, leading=14, leftIndent=14,
                   spaceAfter=2)
NOTE         = mks("Note",        fontSize=9,  textColor=RED, leftIndent=10,
                   fontName="Helvetica-Oblique", spaceAfter=3)
MINDMAP_HDR  = mks("MMHdr",       fontSize=20, textColor=WHITE,
                   alignment=TA_CENTER, fontName="Helvetica-Bold", spaceAfter=6)
MINDMAP_UNIT = mks("MMUnit",      fontSize=13, textColor=WHITE,
                   alignment=TA_CENTER, fontName="Helvetica-Bold")
MINDMAP_PT   = mks("MMPt",        fontSize=9,  textColor=BLACK, leading=12)
Q_STYLE      = mks("QStyle",      fontSize=10, textColor=ORANGE,
                   fontName="Helvetica-Bold", spaceAfter=2)
A_STYLE      = mks("AStyle",      fontSize=10, leading=14, leftIndent=12,
                   spaceAfter=5)

W, H = A4
CONTENT_W = W - 4*cm

# ── helper flowables ──────────────────────────────────────────────────────────

def unit_banner(text, bg=DKBLUE):
    data = [[Paragraph(text, UNIT_HDR)]]
    t = Table(data, colWidths=[CONTENT_W])
    t.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,-1), bg),
        ("TOPPADDING",    (0,0), (-1,-1), 10),
        ("BOTTOMPADDING", (0,0), (-1,-1), 10),
        ("ROUNDEDCORNERS", [6]),
    ]))
    return t

def info_box(title, items, bg=LTBLUE, title_bg=BLUE):
    """Coloured box: bold header row + bullet rows."""
    rows = [[Paragraph(f"<b>{title}</b>", mks("H", fontSize=11,
            textColor=WHITE, fontName="Helvetica-Bold"))]]
    for it in items:
        rows.append([Paragraph(f"• {it}", MINDMAP_PT)])
    t = Table(rows, colWidths=[CONTENT_W])
    style = [
        ("BACKGROUND", (0,0), (0,0), title_bg),
        ("BACKGROUND", (0,1), (-1,-1), bg),
        ("TOPPADDING",    (0,0), (-1,-1), 5),
        ("BOTTOMPADDING", (0,0), (-1,-1), 5),
        ("LEFTPADDING",   (0,0), (-1,-1), 10),
        ("GRID", (0,0), (-1,-1), 0.3, colors.grey),
        ("ROWBACKGROUNDS", (0,1), (-1,-1), [bg, colors.lighten(bg, 0.3)]),
    ]
    t.setStyle(TableStyle(style))
    return t

def two_col_table(headers, rows, col_bg=DKBLUE, alt=LTGREY):
    col_w = [CONTENT_W/len(headers)] * len(headers)
    hrow = [Paragraph(f"<b>{h}</b>", mks("TH", fontSize=10,
            textColor=WHITE, fontName="Helvetica-Bold")) for h in headers]
    data = [hrow]
    for r in rows:
        data.append([Paragraph(str(c), BODY) for c in r])
    t = Table(data, colWidths=col_w, repeatRows=1)
    ts = [
        ("BACKGROUND",    (0,0), (-1,0),  col_bg),
        ("TOPPADDING",    (0,0), (-1,-1), 4),
        ("BOTTOMPADDING", (0,0), (-1,-1), 4),
        ("LEFTPADDING",   (0,0), (-1,-1), 6),
        ("GRID", (0,0), (-1,-1), 0.5, colors.grey),
        ("ROWBACKGROUNDS", (0,1), (-1,-1), [WHITE, alt]),
        ("VALIGN", (0,0), (-1,-1), "TOP"),
    ]
    t.setStyle(TableStyle(ts))
    return t

def flowchart_table(steps, bg=LTBLUE, arrow_color=DKBLUE):
    """Simple vertical flowchart using table cells."""
    data = []
    for i, step in enumerate(steps):
        data.append([Paragraph(step, mks("FC", fontSize=10,
                    textColor=BLACK, fontName="Helvetica", alignment=TA_CENTER))])
        if i < len(steps)-1:
            data.append([Paragraph("<b>▼</b>", mks("AR", fontSize=14,
                        textColor=arrow_color, alignment=TA_CENTER))])
    t = Table(data, colWidths=[CONTENT_W*0.6])
    ts = []
    for i in range(len(data)):
        if i % 2 == 0:  # step rows
            ts += [("BACKGROUND", (0,i), (0,i), bg),
                   ("GRID", (0,i), (0,i), 0.5, colors.grey),
                   ("TOPPADDING",    (0,i), (0,i), 6),
                   ("BOTTOMPADDING", (0,i), (0,i), 6),
                   ("LEFTPADDING",   (0,i), (0,i), 8),
                   ("RIGHTPADDING",  (0,i), (0,i), 8)]
        else:  # arrow rows
            ts += [("BACKGROUND", (0,i), (0,i), WHITE),
                   ("TOPPADDING",    (0,i), (0,i), 0),
                   ("BOTTOMPADDING", (0,i), (0,i), 0)]
    t.setStyle(TableStyle(ts))
    # centre it
    wrapper = Table([[t]], colWidths=[CONTENT_W])
    wrapper.setStyle(TableStyle([("ALIGN", (0,0), (-1,-1), "CENTER"),
                                  ("VALIGN",(0,0), (-1,-1), "MIDDLE")]))
    return wrapper

def sp(h=6):
    return Spacer(1, h)

def hr(color=LTBLUE):
    return HRFlowable(width="100%", thickness=1, color=color, spaceAfter=4, spaceBefore=4)

# ══════════════════════════════════════════════════════════════════════════════
# CONTENT BUILDER
# ══════════════════════════════════════════════════════════════════════════════

def build_story():
    story = []

    # ─── COVER ───────────────────────────────────────────────────────────────
    story += [sp(60),
              Paragraph("CLINICAL BIOCHEMISTRY", COVER_TITLE),
              Paragraph("University Exam Notes — Units VI to X", COVER_SUB),
              sp(10),
              Paragraph("Complete Study Guide with Flowcharts, Diagrams &amp; Mind Map", COVER_SUB),
              sp(20)]
    cover_data = [[Paragraph(
        "<b>Unit VI</b> — Nucleic Acid Metabolism<br/>"
        "<b>Unit VII</b> — Introduction to Clinical Chemistry<br/>"
        "<b>Unit VIII</b> — Liver Function Tests<br/>"
        "<b>Unit IX</b> — Lipid Profile Tests<br/>"
        "<b>Unit X</b> — Electrolytes",
        mks("CL", fontSize=13, textColor=BLACK, leading=22))]]
    cov = Table(cover_data, colWidths=[CONTENT_W])
    cov.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,-1), LTYELLOW),
        ("TOPPADDING",    (0,0), (-1,-1), 20),
        ("BOTTOMPADDING", (0,0), (-1,-1), 20),
        ("LEFTPADDING",   (0,0), (-1,-1), 30),
        ("GRID", (0,0), (-1,-1), 1, YELLOW),
    ]))
    story += [cov, sp(20),
              Paragraph("Prepared for 10-mark University Examinations", NOTE),
              PageBreak()]

    # ══════════════════════════════════════════════════════════════════════════
    # UNIT VI — NUCLEIC ACID METABOLISM
    # ══════════════════════════════════════════════════════════════════════════
    story += [unit_banner("UNIT VI — NUCLEIC ACID METABOLISM", DKBLUE), sp(8)]

    story.append(Paragraph("1. INTRODUCTION", SECTION_HDR))
    story.append(Paragraph(
        "Nucleic acids (DNA &amp; RNA) are polymers of <b>nucleotides</b>. "
        "A nucleotide = Nitrogenous base + Pentose sugar + Phosphate group. "
        "Metabolism includes <b>de novo synthesis</b> (from small molecules) "
        "and <b>salvage pathway</b> (recycling free bases).", BODY))

    # Nucleotide table
    story.append(Paragraph("2. KEY COMPONENTS", SECTION_HDR))
    story.append(two_col_table(
        ["Component", "Purines", "Pyrimidines"],
        [["Bases", "Adenine (A), Guanine (G)", "Cytosine (C), Thymine (T), Uracil (U)"],
         ["Found in", "DNA &amp; RNA", "DNA &amp; RNA"],
         ["Structure", "Double ring (bicyclic)", "Single ring (monocyclic)"],
         ["End product of catabolism", "Uric acid", "CO2 + NH3 + Beta-alanine"]],
        col_bg=DKBLUE
    ))
    story += [sp(6)]

    story.append(Paragraph("3. DE NOVO SYNTHESIS OF PURINES — Flowchart", SECTION_HDR))
    story.append(Paragraph("<b>Precursors:</b> Glycine, Glutamine, Aspartate, CO2, Formate (THF), Ribose-5-phosphate", BODY))
    story += [flowchart_table([
        "Ribose-5-Phosphate (from HMP shunt)",
        "PRPP (5-phosphoribosyl-1-pyrophosphate) [PRPP synthetase]",
        "Phosphoribosylamine (PRA) [Amidophosphoribosyltransferase — rate-limiting step]",
        "10 more steps adding Gly, Gln, Asp, CO2, Formate",
        "IMP (Inosine Monophosphate) — First purine nucleotide",
        "AMP (2 steps via adenylosuccinate) | GMP (2 steps via XMP)",
        "ADP / GDP  →  ATP / GTP  →  DNA/RNA"
    ], bg=LTBLUE, arrow_color=DKBLUE), sp(6)]

    story.append(Paragraph("4. DE NOVO SYNTHESIS OF PYRIMIDINES — Flowchart", SECTION_HDR))
    story.append(Paragraph("<b>Key difference:</b> Ring is built FIRST, then attached to ribose. Precursors: Carbamoyl phosphate + Aspartate", BODY))
    story += [flowchart_table([
        "CO2 + Glutamine + ATP  →  Carbamoyl phosphate (CPS II — cytoplasmic)",
        "Carbamoyl phosphate + Aspartate  →  Carbamoyl aspartate",
        "Dihydroorotate  →  Orotate",
        "Orotate + PRPP  →  OMP (Orotidine monophosphate)",
        "OMP  →  UMP (Uridine monophosphate) — first pyrimidine nucleotide",
        "UMP  →  UDP  →  UTP  →  CTP (cytidine triphosphate)",
        "UDP  →  dUDP  →  dUMP  →  dTMP (thymidine)"
    ], bg=LTGREEN, arrow_color=GREEN), sp(6)]

    story.append(Paragraph("5. SALVAGE PATHWAY", SECTION_HDR))
    story += [info_box("Salvage Pathway — Key Points", [
        "Recycling of free bases from nucleic acid degradation",
        "More energy-efficient than de novo synthesis",
        "Key enzyme for purines: HGPRT (Hypoxanthine-Guanine PhosphoRibosylTransferase)",
        "HGPRT deficiency → Lesch-Nyhan Syndrome (self-mutilation, gout, neurological problems)",
        "Key enzyme for pyrimidines: UPRT (Uracil phosphoribosyltransferase)",
        "ADA deficiency → Severe Combined Immunodeficiency (SCID)"
    ], bg=LTBLUE, title_bg=BLUE), sp(6)]

    story.append(Paragraph("6. DNA REPLICATION — Semi-Conservative Model", SECTION_HDR))
    story.append(Paragraph(
        "<b>Okazaki Fragments</b> are short DNA fragments synthesized on the lagging strand "
        "(3'→5' template) in the 5'→3' direction. They are later joined by DNA Ligase.", BODY))
    story += [flowchart_table([
        "Helicase unwinds double helix at Origin of Replication",
        "SSB proteins stabilize single strands",
        "Primase lays RNA primer (5'→3')",
        "DNA Pol III extends primer: Leading strand — continuous | Lagging strand — Okazaki fragments",
        "DNA Pol I removes RNA primers, fills gaps",
        "DNA Ligase seals nicks → Two identical daughter DNA molecules"
    ], bg=LTYELLOW, arrow_color=ORANGE), sp(6)]

    story.append(Paragraph("7. MUTATIONS", SECTION_HDR))
    story.append(two_col_table(
        ["Type of Mutation", "Definition", "Example / Effect"],
        [["Point Mutation", "Single base change", "Sickle cell anaemia (GAG→GTG)"],
         ["Transition", "Purine↔Purine or Pyrimidine↔Pyrimidine", "A→G or C→T"],
         ["Transversion", "Purine↔Pyrimidine", "A→C or G→T"],
         ["Frameshift", "Insertion/deletion of bases (not in 3s)", "Shifts reading frame"],
         ["Nonsense", "Creates stop codon", "Premature termination"]],
        col_bg=GREEN
    ))
    story += [sp(6)]

    story.append(Paragraph("EXAM TIP — 10 MARKS ANSWER STRUCTURE", SUBSEC_HDR))
    story += [info_box("Unit VI — Exam Answer Template", [
        "1. Introduction (1 mark): Definition of nucleotides, DNA/RNA",
        "2. Types of bases — Purines vs Pyrimidines table (2 marks)",
        "3. De novo synthesis flowchart — Purine (2 marks): PRPP→IMP→AMP/GMP",
        "4. De novo synthesis flowchart — Pyrimidine (2 marks): CPS II→OMP→UMP",
        "5. Salvage pathway + enzyme + disease (2 marks): HGPRT→Lesch-Nyhan",
        "6. DNA replication — Semi-conservative + Okazaki fragments (1 mark)"
    ], bg=LTYELLOW, title_bg=ORANGE), PageBreak()]

    # ══════════════════════════════════════════════════════════════════════════
    # UNIT VII — INTRODUCTION TO CLINICAL CHEMISTRY
    # ══════════════════════════════════════════════════════════════════════════
    story += [unit_banner("UNIT VII — INTRODUCTION TO CLINICAL CHEMISTRY", GREEN), sp(8)]

    story.append(Paragraph("1. CLINICAL LABORATORY", SECTION_HDR))
    story.append(Paragraph(
        "A clinical laboratory is a facility where biological specimens (blood, urine, CSF) "
        "are analyzed to diagnose, monitor, and prevent disease. It includes clinical chemistry, "
        "haematology, microbiology, and immunology sections.", BODY))

    story.append(Paragraph("2. KIDNEY FUNCTION TESTS", SECTION_HDR))
    story.append(Paragraph(
        "Kidneys filter ~180 L of plasma per day. Function is assessed by measuring filtration, "
        "reabsorption, and excretion of various substances.", BODY))
    story += [flowchart_table([
        "BLOOD arrives at Glomerulus",
        "Filtration: GFR ~125 mL/min (Creatinine clearance test measures GFR)",
        "Proximal Tubule: Reabsorbs glucose, amino acids, Na+, HCO3-",
        "Loop of Henle: Concentrates urine (countercurrent mechanism)",
        "Distal Tubule + Collecting Duct: Fine-tune Na+/K+/H2O under ADH/Aldosterone",
        "URINE excreted: 1-1.5 L/day"
    ], bg=LTGREEN, arrow_color=GREEN), sp(6)]

    story.append(Paragraph("3. NPN (Non-Protein Nitrogen) CONSTITUENTS", SECTION_HDR))
    story.append(two_col_table(
        ["NPN Constituent", "Normal Value (Blood)", "Clinical Significance"],
        [["Urea (BUN)", "10-40 mg/dL", "Elevated in renal failure, dehydration"],
         ["Creatinine", "0.6-1.2 mg/dL (M), 0.5-1.1 (F)", "Best marker of GFR; elevated in renal disease"],
         ["Uric Acid", "3.5-7.2 mg/dL (M)", "Elevated in gout, Lesch-Nyhan syndrome"],
         ["Ammonia", "15-45 mcg/dL", "Elevated in liver failure, Reye syndrome"],
         ["Creatine", "0.2-0.8 mg/dL", "Muscle disease marker"]],
        col_bg=TEAL
    ))
    story += [sp(6)]

    story.append(Paragraph("4. URINE ANALYSIS", SECTION_HDR))
    story.append(Paragraph("<b>Normal urine constituents:</b> Water, Urea, Creatinine, NaCl, Uric acid, NH3, Phosphates, Sulphates", BODY))
    story.append(two_col_table(
        ["Abnormal Finding", "Called", "Indicates"],
        [["Glucose in urine", "Glycosuria", "Diabetes mellitus (blood glucose > 180 mg/dL)"],
         ["Protein in urine", "Proteinuria", "Nephrotic syndrome, glomerulonephritis"],
         ["Ketones in urine", "Ketonuria", "Diabetic ketoacidosis, starvation"],
         ["Blood in urine", "Haematuria", "Kidney stones, infection, tumour"],
         ["Bilirubin in urine", "Bilirubinuria", "Obstructive jaundice"],
         ["Pus cells in urine", "Pyuria", "Urinary tract infection (UTI)"]],
        col_bg=PURPLE
    ))
    story += [sp(6)]

    story.append(Paragraph("5. URINARY TRACT CALCULI (STONES)", SECTION_HDR))
    story += [info_box("Types of Urinary Stones", [
        "Calcium Oxalate (most common ~80%): Hard, spiky, radiopaque",
        "Calcium Phosphate: Struvite stones — associated with Proteus UTI",
        "Uric Acid stones: Radiolucent, associated with gout",
        "Cystine stones: Rare, due to cystinuria (amino acid transport defect)",
        "Treatment: Hydration, dietary modification, alkalinisation of urine"
    ], bg=LTPURPLE, title_bg=PURPLE), sp(6)]

    story.append(Paragraph("6. CREATININE CLEARANCE TEST", SECTION_HDR))
    story += [info_box("Creatinine Clearance — Formula", [
        "Clearance (mL/min) = [Urine Creatinine (mg/dL) × Urine Volume (mL/min)] / Serum Creatinine (mg/dL)",
        "Normal: 80-120 mL/min (male), 75-115 mL/min (female)",
        "Best test for estimating GFR (Glomerular Filtration Rate)",
        "Decreased in: Chronic Kidney Disease, Acute Renal Failure, Dehydration"
    ], bg=LTTEAL, title_bg=TEAL), sp(6)]

    story.append(Paragraph("EXAM TIP — 10 MARKS ANSWER STRUCTURE", SUBSEC_HDR))
    story += [info_box("Unit VII — Exam Answer Template", [
        "1. Introduction: Role of clinical chemistry lab (1 mark)",
        "2. Kidney anatomy + function diagram — filtration, reabsorption, secretion (2 marks)",
        "3. NPN constituents table — Urea, Creatinine, Uric acid, values (2 marks)",
        "4. Creatinine clearance formula + significance (2 marks)",
        "5. Urine analysis — normal vs abnormal constituents table (2 marks)",
        "6. Urinary tract calculi — types + causes (1 mark)"
    ], bg=LTYELLOW, title_bg=ORANGE), PageBreak()]

    # ══════════════════════════════════════════════════════════════════════════
    # UNIT VIII — LIVER FUNCTION TESTS
    # ══════════════════════════════════════════════════════════════════════════
    story += [unit_banner("UNIT VIII — LIVER FUNCTION TESTS (LFTs)", TEAL), sp(8)]

    story.append(Paragraph("1. FUNCTIONS OF THE LIVER", SECTION_HDR))
    story += [info_box("Major Liver Functions (Mnemonics: MEDS-PC)", [
        "M — Metabolism: Carbohydrate, protein, lipid metabolism (gluconeogenesis, glycogen storage)",
        "E — Excretion: Bile pigments (bilirubin), drugs, toxins",
        "D — Detoxification: Converts ammonia → urea (urea cycle); Phase I &amp; II drug metabolism",
        "S — Synthesis: Albumin, clotting factors (I, II, V, VII, IX, X), complement",
        "P — Production: Bile acids (from cholesterol) — essential for fat digestion",
        "C — Conjugation: Bilirubin conjugation with glucuronic acid"
    ], bg=LTTEAL, title_bg=TEAL), sp(6)]

    story.append(Paragraph("2. BILIRUBIN METABOLISM — Flowchart", SECTION_HDR))
    story += [flowchart_table([
        "Haemoglobin breakdown (RBCs destroyed in spleen/liver — 120 days)",
        "Haem → Biliverdin → Unconjugated Bilirubin (indirect, fat-soluble, toxic)",
        "Unconjugated bilirubin + Albumin → Transported to liver",
        "Liver: UDP-glucuronyltransferase conjugates bilirubin → Conjugated Bilirubin (direct, water-soluble)",
        "Conjugated bilirubin secreted into bile → Intestine",
        "Intestinal bacteria: Bilirubin → Urobilinogen → Stercobilin (brown stool colour)",
        "Some urobilinogen reabsorbed → Kidney → Urobilin (yellow urine colour)"
    ], bg=LTYELLOW, arrow_color=ORANGE), sp(6)]

    story.append(Paragraph("3. JAUNDICE — TYPES &amp; DIFFERENTIATION", SECTION_HDR))
    story.append(two_col_table(
        ["Feature", "Pre-hepatic (Haemolytic)", "Hepatic (Hepatocellular)", "Post-hepatic (Obstructive)"],
        [["Cause", "Excess RBC destruction", "Liver cell damage (hepatitis, cirrhosis)", "Bile duct blockage (stones, tumour)"],
         ["Unconjugated Bil", "↑↑ Increased", "↑ Increased", "Normal/slight ↑"],
         ["Conjugated Bil", "Normal", "↑ Increased", "↑↑ Increased"],
         ["Urine Bilirubin", "Absent", "Present", "Present (dark urine)"],
         ["Stool colour", "Normal/dark", "Pale", "Clay-coloured (pale)"],
         ["SGOT/SGPT", "Normal", "Very high", "Moderately elevated"],
         ["ALP", "Normal", "Elevated", "Very high"]],
        col_bg=TEAL
    ))
    story += [sp(6)]

    story.append(Paragraph("4. LIVER ENZYMES — SGOT &amp; SGPT", SECTION_HDR))
    story += [info_box("SGOT (AST) vs SGPT (ALT)", [
        "SGPT (ALT = Alanine Aminotransferase): LIVER-SPECIFIC — most sensitive marker",
        "SGOT (AST = Aspartate Aminotransferase): Found in liver, heart, muscle, kidney",
        "Normal SGPT: 7-56 U/L | Normal SGOT: 10-40 U/L",
        "De Ritis Ratio = AST/ALT: >2 suggests alcoholic liver disease; <1 suggests viral hepatitis",
        "Principle: Amino group transfer from alanine/aspartate → alpha-ketoglutarate → pyruvate/oxaloacetate",
        "Measured by colorimetric or UV spectrophotometric method"
    ], bg=LTTEAL, title_bg=TEAL), sp(6)]

    story.append(Paragraph("5. OTHER LIVER FUNCTION TESTS", SECTION_HDR))
    story.append(two_col_table(
        ["Test", "Normal Value", "What It Tests", "Clinical Use"],
        [["Serum Bilirubin (Total)", "0.3-1.2 mg/dL", "Bilirubin metabolism", "Jaundice diagnosis"],
         ["Serum Albumin", "3.5-5.5 g/dL", "Synthetic function", "Chronic liver disease"],
         ["Prothrombin Time (PT)", "11-13 seconds", "Clotting factor synthesis", "Liver synthetic function"],
         ["Alkaline Phosphatase (ALP)", "44-147 U/L", "Cholestasis/bone", "Obstructive jaundice"],
         ["Gamma GT (GGT)", "0-51 U/L", "Alcohol intake, cholestasis", "Alcohol liver disease"],
         ["Serum Proteins", "6.5-8.5 g/dL", "Total + albumin/globulin ratio", "Liver protein synthesis"]],
        col_bg=TEAL
    ))
    story += [sp(6)]

    story.append(Paragraph("6. HEPATIC DYSFUNCTION TESTS", SECTION_HDR))
    story += [info_box("Tests for Hepatic Dysfunction — Metabolic &amp; Detoxification Capacity", [
        "Bromsulphalein (BSP) Retention Test: Dye injected IV; liver clears it. Retention >5% at 45 min = hepatic dysfunction",
        "Serum Hippuric Acid Test (Quick test): Sodium benzoate given → liver conjugates → hippuric acid in urine. Reduced in liver damage",
        "Blood Ammonia: Elevated in hepatic encephalopathy (liver fails to convert NH3 → urea)",
        "Indocyanine Green (ICG) Clearance: Gold standard for hepatic blood flow and function",
        "Galactose Elimination Capacity: Tests hepatocyte mass"
    ], bg=LTRED, title_bg=RED), sp(6)]

    story.append(Paragraph("EXAM TIP — 10 MARKS ANSWER STRUCTURE", SUBSEC_HDR))
    story += [info_box("Unit VIII — Exam Answer Template", [
        "1. Functions of liver — MEDS-PC mnemonic table (2 marks)",
        "2. Bilirubin metabolism flowchart (2 marks)",
        "3. Types of jaundice table — 3 types, 5 differentiating features (3 marks)",
        "4. SGOT/SGPT — principle, normal values, De Ritis ratio (2 marks)",
        "5. Other LFTs table — Albumin, ALP, PT (1 mark)"
    ], bg=LTYELLOW, title_bg=ORANGE), PageBreak()]

    # ══════════════════════════════════════════════════════════════════════════
    # UNIT IX — LIPID PROFILE TESTS
    # ══════════════════════════════════════════════════════════════════════════
    story += [unit_banner("UNIT IX — LIPID PROFILE TESTS", PURPLE), sp(8)]

    story.append(Paragraph("1. PHOSPHOLIPIDS", SECTION_HDR))
    story += [info_box("Phospholipids — Structure &amp; Functions", [
        "Structure: Glycerol backbone + 2 fatty acids + Phosphate group + Polar head",
        "Examples: Lecithin (phosphatidylcholine), Cephalin, Sphingomyelin, Cardiolipin",
        "Functions: Major component of cell membranes (bilayer structure)",
        "Act as emulsifiers for lipid digestion (bile contains lecithin)",
        "Lung surfactant — Lecithin prevents alveolar collapse (L:S ratio >2 = lung maturity)",
        "Blood clotting: Cephalin (thromboplastin) activates clotting cascade"
    ], bg=LTPURPLE, title_bg=PURPLE), sp(6)]

    story.append(Paragraph("2. LIPOPROTEINS — Structure, Types &amp; Functions", SECTION_HDR))
    story.append(Paragraph("Lipoproteins transport lipids in blood (lipids are insoluble in water). Structure: Core (cholesteryl esters + triglycerides) surrounded by phospholipid shell + apoproteins.", BODY))
    story.append(two_col_table(
        ["Lipoprotein", "Density", "Composition", "Function", "Clinical Link"],
        [["Chylomicrons", "Lowest", "90% TG", "Transport dietary fat from gut to tissues", "Elevated in familial hypertriglyceridaemia"],
         ["VLDL", "Very Low", "55% TG, 15% Chol", "Endogenous TG transport liver→tissues", "Precursor to LDL"],
         ["IDL", "Intermediate", "TG+Chol", "Transient; converted to LDL", "Elevated in Type III hyperlipidaemia"],
         ["LDL", "Low", "45% Chol", "Transport cholesterol to cells — 'BAD'", "Major risk factor for atherosclerosis"],
         ["HDL", "High", "50% Protein", "Reverse cholesterol transport — 'GOOD'", "Protective against CVD"]],
        col_bg=PURPLE
    ))
    story += [sp(6)]

    story.append(Paragraph("3. TOTAL CHOLESTEROL DETERMINATION", SECTION_HDR))
    story.append(Paragraph("<b>Liebermann-Burchard Method (Classic):</b>", SUBSEC_HDR))
    story += [flowchart_table([
        "Serum + Acetic Anhydride + H2SO4 (Liebermann-Burchard reagent)",
        "Cholesterol is dehydrated and oxidised",
        "Green colour develops (via polyene formation)",
        "Read at 620 nm (spectrophotometer)",
        "Calculate concentration from standard curve",
        "Normal: Total Cholesterol <200 mg/dL (desirable)"
    ], bg=LTPURPLE, arrow_color=PURPLE), sp(4)]
    story.append(Paragraph("<b>Enzymatic Method (Modern/Preferred):</b> Cholesterol Oxidase-Peroxidase (CHOD-PAP) method — more accurate, automated.", BODY))
    story += [sp(6)]

    story.append(Paragraph("4. HDL &amp; LDL DETERMINATION", SECTION_HDR))
    story += [info_box("HDL and LDL Measurement", [
        "HDL-C: Direct method (homogeneous assay) or after precipitation of LDL/VLDL with phosphotungstate-MgCl2",
        "LDL-C: Friedewald Formula: LDL = Total Cholesterol - HDL - (Triglycerides/5) [valid if TG <400 mg/dL]",
        "Normal HDL: >40 mg/dL (M), >50 mg/dL (F) — higher is better",
        "Normal LDL: <100 mg/dL (optimal), 100-129 near optimal, >160 high risk",
        "Atherogenic Index = LDL/HDL — should be <3.5"
    ], bg=LTPURPLE, title_bg=PURPLE), sp(6)]

    story.append(Paragraph("5. RIA (RADIOIMMUNOASSAY)", SECTION_HDR))
    story += [flowchart_table([
        "Principle: Competition between labelled antigen (Ag*) and unlabelled antigen for limited antibody (Ab)",
        "Step 1: Fixed amount of Ab + known Ag* (radiolabelled) + unknown sample Ag added",
        "Step 2: Ag and Ag* compete for Ab binding sites",
        "Step 3: Separate bound (Ag*-Ab) from free (Ag*) using precipitation",
        "Step 4: Measure radioactivity of bound fraction (Gamma counter)",
        "Step 5: More sample Ag → Less Ag* bound → Less radioactivity → Calculate concentration"
    ], bg=LTRED, arrow_color=RED), sp(4)]
    story += [info_box("RIA — Advantages &amp; Disadvantages", [
        "Advantages: Extremely sensitive (detects pg/mL), highly specific, quantitative",
        "Advantages: Can measure any antigen if antibody available (hormones, drugs, lipoproteins)",
        "Disadvantages: Radioactive hazard, short shelf life of reagents, expensive, requires special facility",
        "Disadvantages: Strict regulations for isotope handling (125-Iodine most commonly used)",
        "Applications: Measuring hormones (insulin, TSH), drugs, lipoproteins, vitamins"
    ], bg=LTRED, title_bg=RED), sp(6)]

    story.append(Paragraph("6. ELISA (Enzyme-Linked Immunosorbent Assay)", SECTION_HDR))
    story += [flowchart_table([
        "Step 1: Coat microtitre plate wells with capture antibody (Ab1)",
        "Step 2: Add patient sample — antigen binds to Ab1 (INCUBATE + WASH)",
        "Step 3: Add enzyme-linked detection antibody (Ab2-Enzyme conjugate) — SANDWICH ELISA",
        "Step 4: Add substrate — enzyme converts substrate → coloured product",
        "Step 5: Stop reaction with H2SO4 (acid)",
        "Step 6: Read Absorbance at 450 nm → proportional to antigen concentration"
    ], bg=LTBLUE, arrow_color=DKBLUE), sp(4)]
    story += [info_box("ELISA — Key Facts", [
        "Types: Direct ELISA, Indirect ELISA, Sandwich ELISA (most sensitive), Competitive ELISA",
        "Enzyme used: HRP (Horseradish Peroxidase) or Alkaline Phosphatase",
        "Substrate for HRP: TMB (turns blue) → Yellow after stopping",
        "Advantages: No radioactivity, safe, cheap, automated, long shelf life",
        "Disadvantages: Less sensitive than RIA, matrix effects possible",
        "Applications: HIV diagnosis, Hepatitis B, lipid-associated proteins, drug monitoring"
    ], bg=LTBLUE, title_bg=DKBLUE), sp(6)]

    story.append(Paragraph("EXAM TIP — 10 MARKS ANSWER STRUCTURE", SUBSEC_HDR))
    story += [info_box("Unit IX — Exam Answer Template", [
        "1. Lipoproteins table — 5 types, density, function (3 marks)",
        "2. Total cholesterol determination — Liebermann-Burchard method/CHOD-PAP (2 marks)",
        "3. HDL/LDL — direct methods + Friedewald formula (1 mark)",
        "4. RIA — principle + flowchart + advantages/disadvantages (2 marks)",
        "5. ELISA — principle + flowchart + sandwich ELISA diagram (2 marks)"
    ], bg=LTYELLOW, title_bg=ORANGE), PageBreak()]

    # ══════════════════════════════════════════════════════════════════════════
    # UNIT X — ELECTROLYTES
    # ══════════════════════════════════════════════════════════════════════════
    story += [unit_banner("UNIT X — ELECTROLYTES", RED), sp(8)]

    story.append(Paragraph("1. BODY FLUID COMPARTMENTS", SECTION_HDR))
    story.append(Paragraph(
        "Total Body Water (TBW) = 60% of body weight. Divided into:", BODY))
    story.append(two_col_table(
        ["Compartment", "% Body Weight", "Volume (70 kg)", "Major Ions"],
        [["Intracellular Fluid (ICF)", "40%", "28 L", "K+, Mg2+, HPO4-"],
         ["Extracellular Fluid (ECF)", "20%", "14 L", "Na+, Cl-, HCO3-"],
         ["  → Plasma (Intravascular)", "5%", "3.5 L", "Na+, Proteins"],
         ["  → Interstitial Fluid", "15%", "10.5 L", "Na+, Cl-"],
         ["Transcellular Fluid", "1-2%", "<1 L", "Variable (CSF, joint fluid)"]],
        col_bg=RED
    ))
    story += [sp(6)]

    story.append(Paragraph("2. SODIUM (Na+) — DETERMINATION &amp; REGULATION", SECTION_HDR))
    story.append(Paragraph(
        "Sodium is the major extracellular cation. Normal serum Na+: <b>135-145 mEq/L</b>. "
        "It determines plasma osmolality and ECF volume.", BODY))
    story += [info_box("Methods to Determine Sodium in Body Fluids", [
        "Flame Photometry (Flame Emission Spectroscopy): GOLD STANDARD — sodium burns orange-yellow at 589 nm",
        "Ion-Selective Electrode (ISE): Most commonly used in automated analysers; measures Na+ activity",
        "Atomic Absorption Spectroscopy: Highly accurate but expensive",
        "Colorimetric methods: Uranyl zinc acetate method (less common)"
    ], bg=LTRED, title_bg=RED), sp(6)]

    story.append(Paragraph("3. REGULATION OF SODIUM &amp; OSMOLARITY", SECTION_HDR))
    story += [flowchart_table([
        "Low BP / Low Na+ / Low ECF Volume detected by Juxtaglomerular cells in kidney",
        "Renin released → Angiotensinogen → Angiotensin I (in plasma)",
        "ACE (Angiotensin-Converting Enzyme) converts → Angiotensin II",
        "Angiotensin II → Stimulates Adrenal Cortex → Aldosterone released",
        "Aldosterone → Acts on DCT/Collecting duct → ↑ Na+ reabsorption + K+ excretion",
        "Na+ retained → Water follows osmotically → ECF volume restored",
        "High osmolarity → ADH (Vasopressin) released from posterior pituitary → Water retention"
    ], bg=LTRED, arrow_color=RED), sp(6)]

    story.append(Paragraph("4. CHLORIDE (Cl-) DETERMINATION", SECTION_HDR))
    story += [info_box("Chloride in Body Fluids", [
        "Normal serum Cl-: 95-105 mEq/L (follows Na+ changes)",
        "Schales and Schales Method: Titration with mercuric nitrate using diphenylcarbazone indicator — endpoint = blue-violet colour",
        "Cotlove's Coulometric Titration: Silver ions generated electrochemically react with Cl-",
        "ISE (Ion-Selective Electrode): Routine automated method",
        "ORS (Oral Rehydration Solution): NaCl + KCl + Glucose + Na-Citrate — WHO formula",
        "Hyperchloric acidosis: ↑ Cl- with ↓ HCO3-"
    ], bg=LTRED, title_bg=RED), sp(6)]

    story.append(Paragraph("5. WATER DEPLETION &amp; WATER EXCESS", SECTION_HDR))
    story.append(two_col_table(
        ["Parameter", "Water Depletion (Dehydration)", "Water Excess (Overhydration)"],
        [["Serum Na+", "↑ Hypernatraemia", "↓ Hyponatraemia"],
         ["Serum Osmolality", "↑ High", "↓ Low"],
         ["Urine Output", "↓ Oliguria/Anuria", "↑ Polyuria"],
         ["Clinical Features", "Thirst, dry mucous membranes, tachycardia", "Oedema, weight gain, confusion"],
         ["Causes", "Vomiting, diarrhoea, burns, inadequate intake", "Excess IV fluids, SIADH, cardiac failure"],
         ["Treatment", "Oral/IV fluid replacement, ORS", "Fluid restriction, diuretics"]],
        col_bg=RED
    ))
    story += [sp(6)]

    story.append(Paragraph("6. HYPOKALAEMIA &amp; HYPERKALAEMIA", SECTION_HDR))
    story.append(Paragraph("Normal serum K+: <b>3.5-5.0 mEq/L</b>. Potassium is the major intracellular cation.", BODY))
    story.append(two_col_table(
        ["Feature", "Hypokalaemia (K+ < 3.5)", "Hyperkalaemia (K+ > 5.0)"],
        [["Causes", "Vomiting, diarrhoea, diuretics, hyperaldosteronism", "Renal failure, ACE inhibitors, acidosis, Addison's disease"],
         ["ECG Changes", "U waves, flat T waves, prolonged QT", "Peaked T waves, wide QRS, sine wave pattern"],
         ["Symptoms", "Muscle weakness, cramps, paralysis, arrhythmias", "Palpitations, weakness, cardiac arrest"],
         ["Treatment", "K+ supplementation (oral/IV KCl)", "Calcium gluconate, insulin+dextrose, dialysis"]],
        col_bg=RED
    ))
    story += [sp(6)]

    story.append(Paragraph("7. HYPONATRAEMIA &amp; HYPERNATRAEMIA", SECTION_HDR))
    story.append(two_col_table(
        ["Feature", "Hyponatraemia (Na+ < 135)", "Hypernatraemia (Na+ > 145)"],
        [["Causes", "SIADH, heart failure, cirrhosis, hypothyroidism", "Dehydration, diabetes insipidus, excess salt intake"],
         ["Symptoms", "Headache, confusion, seizures, coma", "Thirst, fever, restlessness, muscle twitching"],
         ["Treatment", "Fluid restriction (dilutional), hypertonic saline (severe)", "Free water replacement (oral/IV), treat cause"]],
        col_bg=RED
    ))
    story += [sp(6)]

    story.append(Paragraph("8. ROLE OF ALDOSTERONE IN ELECTROLYTE REGULATION", SECTION_HDR))
    story += [info_box("Aldosterone — Key Points", [
        "Produced by Zona Glomerulosa of Adrenal Cortex (mineralocorticoid)",
        "Stimulus: Low Na+, High K+, Low blood volume, Angiotensin II, ACTH",
        "Action: ↑ Na+ reabsorption at DCT/CD by upregulating ENaC (Na+ channel) and Na+/K+ ATPase",
        "Effect: Na+ retained + K+ excreted + H+ excreted + Water retained (via osmosis)",
        "Primary Hyperaldosteronism (Conn's Syndrome): High BP, Low K+, Low Renin",
        "Primary Hypoaldosteronism (Addison's Disease): Low Na+, High K+, Low BP"
    ], bg=LTRED, title_bg=RED), sp(6)]

    story.append(Paragraph("EXAM TIP — 10 MARKS ANSWER STRUCTURE", SUBSEC_HDR))
    story += [info_box("Unit X — Exam Answer Template", [
        "1. Body fluid compartments diagram — ICF/ECF table (2 marks)",
        "2. Sodium determination methods — Flame photometry + ISE principle (2 marks)",
        "3. Aldosterone regulation flowchart — RAAS pathway (2 marks)",
        "4. Hypo/Hypernatraemia + Hypo/Hyperkalaemia tables (2 marks)",
        "5. Water depletion vs excess table + ORS composition (2 marks)"
    ], bg=LTYELLOW, title_bg=ORANGE), PageBreak()]

    # ══════════════════════════════════════════════════════════════════════════
    # MIND MAP — QUICK RECAP
    # ══════════════════════════════════════════════════════════════════════════
    story += [unit_banner("MIND MAP — QUICK RECAP (All Units)", GREY), sp(10)]

    # One large mind map table
    mm_data = [
        # Header row
        [Paragraph("<b>UNIT VI</b><br/>Nucleic Acid<br/>Metabolism", MINDMAP_UNIT),
         Paragraph("<b>UNIT VII</b><br/>Clinical<br/>Chemistry", MINDMAP_UNIT),
         Paragraph("<b>UNIT VIII</b><br/>Liver Function<br/>Tests", MINDMAP_UNIT),
         Paragraph("<b>UNIT IX</b><br/>Lipid Profile<br/>Tests", MINDMAP_UNIT),
         Paragraph("<b>UNIT X</b><br/>Electrolytes", MINDMAP_UNIT)],
        # Row 1
        [Paragraph("• Nucleotides = Base + Sugar + Pi\n• Purines: A, G (bicyclic)\n• Pyrimidines: C, T, U (monocyclic)", MINDMAP_PT),
         Paragraph("• Lab: Blood, Urine, CSF analysis\n• GFR = 125 mL/min\n• NPN = Urea + Creatinine + Uric acid", MINDMAP_PT),
         Paragraph("• MEDS-PC functions\n• Bilirubin: Unconjugated→Conjugated\n• UDP-glucuronyl transferase", MINDMAP_PT),
         Paragraph("• Phospholipids: Cell membrane\n• Lipoproteins: Chylomicron, VLDL, LDL, HDL\n• HDL = GOOD, LDL = BAD", MINDMAP_PT),
         Paragraph("• TBW = 60% body wt\n• ICF: K+ dominant (40%)\n• ECF: Na+ dominant (20%)", MINDMAP_PT)],
        # Row 2
        [Paragraph("• De novo Purines: PRPP→IMP→AMP/GMP\n• Rate-limiting: amidoPRTase\n• Pyrimidines: CPS II→OMP→UMP", MINDMAP_PT),
         Paragraph("• Creatinine clearance: best GFR test\n• Formula: UV/P\n• Abnormal urine: Glycosuria, Proteinuria", MINDMAP_PT),
         Paragraph("• Jaundice types: Pre/Hepatic/Post-hepatic\n• SGPT = liver-specific (ALT)\n• SGOT = heart+liver (AST)\n• De Ritis ratio = AST/ALT", MINDMAP_PT),
         Paragraph("• Cholesterol: LB method / CHOD-PAP\n• LDL = TC - HDL - TG/5\n• Normal TC <200 mg/dL", MINDMAP_PT),
         Paragraph("• Na+ normal: 135-145 mEq/L\n• K+ normal: 3.5-5.0 mEq/L\n• Cl- normal: 95-105 mEq/L", MINDMAP_PT)],
        # Row 3
        [Paragraph("• Salvage pathway: HGPRT\n• HGPRT deficiency → Lesch-Nyhan\n• ADA deficiency → SCID\n• Okazaki fragments: lagging strand", MINDMAP_PT),
         Paragraph("• Urinary stones: Ca-oxalate most common\n• Uric acid stones: radiolucent\n• Cystine stones: cystinuria", MINDMAP_PT),
         Paragraph("• Albumin: 3.5-5.5 g/dL (synthetic fn)\n• ALP: Obstructive jaundice marker\n• BSP test: detox capacity\n• PT: clotting factor synthesis", MINDMAP_PT),
         Paragraph("• RIA: Radiolabelled Ag* vs Ag for Ab\n• Advantages: Very sensitive (pg/mL)\n• Dis: Radioactive hazard", MINDMAP_PT),
         Paragraph("• Flame photometry: Na+ at 589 nm\n• ISE: routine automated\n• Aldosterone: Na+ retention, K+ excretion", MINDMAP_PT)],
        # Row 4
        [Paragraph("• Mutations: Point, Transition, Transversion, Frameshift, Nonsense\n• Semi-conservative replication\n• Helicase→Primase→DNA Pol III→Ligase", MINDMAP_PT),
         Paragraph("• Bile salts: Conjugated bile acids\n• Bile pigments: Bilirubin/Urobilinogen\n• Serum protein electrophoresis", MINDMAP_PT),
         Paragraph("• Hepatic dysfunction: blood ammonia↑\n• Ammonia→Urea (fails in liver disease)\n• ICG clearance: hepatic blood flow", MINDMAP_PT),
         Paragraph("• ELISA: Ab coated plate→Ag→Ab2-Enzyme\n• Substrate→Colour→Absorbance at 450nm\n• Sandwich ELISA most sensitive", MINDMAP_PT),
         Paragraph("• RAAS: Renin→Ang I→Ang II→Aldosterone\n• ADH: Water retention (posterior pit.)\n• ORS: NaCl+KCl+Glucose+Na-Citrate", MINDMAP_PT)],
    ]

    col_w = [CONTENT_W/5]*5
    mm_table = Table(mm_data, colWidths=col_w)
    ts = [
        ("BACKGROUND", (0,0), (0,0), DKBLUE),
        ("BACKGROUND", (1,0), (1,0), GREEN),
        ("BACKGROUND", (2,0), (2,0), TEAL),
        ("BACKGROUND", (3,0), (3,0), PURPLE),
        ("BACKGROUND", (4,0), (4,0), RED),
        ("BACKGROUND", (0,1), (0,-1), LTBLUE),
        ("BACKGROUND", (1,1), (1,-1), LTGREEN),
        ("BACKGROUND", (2,1), (2,-1), LTTEAL),
        ("BACKGROUND", (3,1), (3,-1), LTPURPLE),
        ("BACKGROUND", (4,1), (4,-1), LTRED),
        ("GRID", (0,0), (-1,-1), 0.5, colors.grey),
        ("VALIGN", (0,0), (-1,-1), "TOP"),
        ("TOPPADDING",    (0,0), (-1,-1), 6),
        ("BOTTOMPADDING", (0,0), (-1,-1), 6),
        ("LEFTPADDING",   (0,0), (-1,-1), 6),
        ("ALIGN", (0,0), (-1,0), "CENTER"),
    ]
    mm_table.setStyle(TableStyle(ts))
    story.append(mm_table)
    story += [sp(10)]

    # ── SUMMARY TABLE ─────────────────────────────────────────────────────────
    story += [unit_banner("FINAL SUMMARY — LAST MINUTE REVISION", GREY), sp(8)]
    story.append(two_col_table(
        ["Unit", "Most Important Exam Points"],
        [["VI: Nucleic Acid", "PRPP synthetase (rate-limiting) → IMP → AMP/GMP | HGPRT deficiency = Lesch-Nyhan | Okazaki fragments on lagging strand | Pyrimidines: CPS II → OMP → UMP"],
         ["VII: Clinical Chem", "GFR = 125 mL/min | Creatinine clearance = best GFR test | Ca-oxalate = most common stone | Glycosuria when blood glucose >180 mg/dL"],
         ["VIII: LFT", "Conjugated bilirubin = direct = water-soluble | SGPT = liver-specific (ALT) | De Ritis ratio >2 = alcoholic liver | ALP very high = obstructive jaundice"],
         ["IX: Lipid Profile", "LDL = TC - HDL - TG/5 (Friedewald) | HDL = good, LDL = bad | RIA = radiolabelled antigen competition | ELISA = enzyme-linked, 450 nm"],
         ["X: Electrolytes", "Na+ = 135-145, K+ = 3.5-5.0, Cl- = 95-105 mEq/L | Aldosterone: Na+ up, K+ down | Flame photometry = 589 nm | ORS = NaCl+KCl+Glucose"]],
        col_bg=GREY
    ))
    story += [sp(10)]

    story.append(Paragraph(
        "<b>Good Luck in Your Exams!</b> Remember: Draw flowcharts and tables — they earn marks faster than paragraphs.",
        mks("GL", fontSize=13, textColor=DKBLUE, alignment=TA_CENTER, fontName="Helvetica-Bold")))

    return story


# ── BUILD PDF ─────────────────────────────────────────────────────────────────
OUT = "/home/daytona/workspace/biochem-notes/ClinicalBiochem_UnitsVI_X_ExamNotes.pdf"

doc = SimpleDocTemplate(
    OUT, pagesize=A4,
    leftMargin=2*cm, rightMargin=2*cm,
    topMargin=2*cm, bottomMargin=2*cm,
    title="Clinical Biochemistry Units VI-X — University Exam Notes",
    author="Orris AI Study Assistant"
)

doc.build(build_story())
print(f"PDF created: {OUT}")

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/biochem-notes/create_notes.py'