Hypertension: A Comprehensive Review

#!/usr/bin/env python3
"""
Hypertension Study Guide PDF - Exam Prep
Built with ReportLab
"""

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

# ── Colour palette ──────────────────────────────────────────────────────────
NAVY       = HexColor("#1a2b5e")
MED_BLUE   = HexColor("#2563eb")
LIGHT_BLUE = HexColor("#dbeafe")
TEAL       = HexColor("#0d9488")
TEAL_LIGHT = HexColor("#ccfbf1")
RED        = HexColor("#dc2626")
RED_LIGHT  = HexColor("#fee2e2")
ORANGE     = HexColor("#ea580c")
ORANGE_LIGHT = HexColor("#ffedd5")
GREY_DARK  = HexColor("#374151")
GREY_MID   = HexColor("#6b7280")
GREY_LIGHT = HexColor("#f3f4f6")
WHITE      = colors.white
GREEN      = HexColor("#16a34a")
GREEN_LIGHT= HexColor("#dcfce7")
PURPLE     = HexColor("#7c3aed")
PURPLE_LIGHT = HexColor("#ede9fe")
YELLOW_LIGHT = HexColor("#fef9c3")

# ── Output path ─────────────────────────────────────────────────────────────
OUT = "/tmp/workspace/hypertension-study-guide/Hypertension_Study_Guide.pdf"
doc = SimpleDocTemplate(
    OUT,
    pagesize=A4,
    leftMargin=18*mm, rightMargin=18*mm,
    topMargin=22*mm, bottomMargin=22*mm,
    title="Hypertension – Complete Study Guide",
    author="Orris Medical AI",
)

W, H = A4
CONTENT_W = W - 36*mm

# ── Styles ───────────────────────────────────────────────────────────────────
base = getSampleStyleSheet()

def style(name, **kw):
    s = ParagraphStyle(name, **kw)
    return s

S_TITLE = style("DocTitle",
    fontSize=24, textColor=WHITE, alignment=TA_CENTER,
    fontName="Helvetica-Bold", leading=30, spaceAfter=6)

S_SUBTITLE = style("DocSubtitle",
    fontSize=12, textColor=LIGHT_BLUE, alignment=TA_CENTER,
    fontName="Helvetica", leading=16)

S_SECTION = style("SectionHead",
    fontSize=13, textColor=WHITE, fontName="Helvetica-Bold",
    leading=18, spaceBefore=4, spaceAfter=4,
    leftIndent=6, rightIndent=6)

S_SUBSEC = style("SubsectionHead",
    fontSize=10.5, textColor=NAVY, fontName="Helvetica-Bold",
    leading=14, spaceBefore=6, spaceAfter=3,
    borderPad=2)

S_BODY = style("Body",
    fontSize=9, textColor=GREY_DARK, fontName="Helvetica",
    leading=13, spaceAfter=2, alignment=TA_JUSTIFY)

S_BULLET = style("Bullet",
    fontSize=9, textColor=GREY_DARK, fontName="Helvetica",
    leading=13, spaceAfter=2,
    leftIndent=12, firstLineIndent=-10)

S_SUBBULLET = style("SubBullet",
    fontSize=8.5, textColor=GREY_DARK, fontName="Helvetica",
    leading=12, spaceAfter=1,
    leftIndent=24, firstLineIndent=-10)

S_TABLE_HDR = style("TblHdr",
    fontSize=8.5, textColor=WHITE, fontName="Helvetica-Bold",
    alignment=TA_CENTER, leading=11)

S_TABLE_CELL = style("TblCell",
    fontSize=8, textColor=GREY_DARK, fontName="Helvetica",
    leading=11, alignment=TA_LEFT)

S_TABLE_CELL_C = style("TblCellC",
    fontSize=8, textColor=GREY_DARK, fontName="Helvetica",
    leading=11, alignment=TA_CENTER)

S_HIGHLIGHT = style("Highlight",
    fontSize=9, textColor=NAVY, fontName="Helvetica-Bold",
    leading=13, spaceAfter=3, spaceBefore=3,
    backColor=YELLOW_LIGHT, borderPad=4,
    leftIndent=8, rightIndent=8)

S_MNEMONIC = style("Mnemonic",
    fontSize=9.5, textColor=PURPLE, fontName="Helvetica-Bold",
    leading=14, spaceAfter=4, spaceBefore=4,
    alignment=TA_CENTER)

S_ALERT = style("Alert",
    fontSize=9, textColor=RED, fontName="Helvetica-Bold",
    leading=13, spaceAfter=3, leftIndent=8)

S_TOC = style("TOC",
    fontSize=10, textColor=NAVY, fontName="Helvetica",
    leading=16, leftIndent=8)

S_TOC_ITEM = style("TOCItem",
    fontSize=9.5, textColor=GREY_DARK, fontName="Helvetica",
    leading=14, leftIndent=20)

# ── Helper builders ──────────────────────────────────────────────────────────

def section_header(title, color=NAVY):
    """Coloured full-width section banner."""
    tbl = Table([[Paragraph(title, S_SECTION)]], colWidths=[CONTENT_W])
    tbl.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,-1), color),
        ("ROWBACKGROUNDS", (0,0), (-1,-1), [color]),
        ("TOPPADDING",    (0,0), (-1,-1), 5),
        ("BOTTOMPADDING", (0,0), (-1,-1), 5),
        ("LEFTPADDING",   (0,0), (-1,-1), 8),
        ("RIGHTPADDING",  (0,0), (-1,-1), 8),
        ("ROUNDEDCORNERS", [4]),
    ]))
    return tbl

def colored_box(content_items, bg_color, border_color=None, radius=4):
    """Wrap a list of flowables in a coloured rounded box using a 1-cell table."""
    inner = Table([[item] for item in content_items],
                  colWidths=[CONTENT_W - 16])
    inner.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,-1), bg_color),
        ("TOPPADDING",    (0,0), (-1,-1), 0),
        ("BOTTOMPADDING", (0,0), (-1,-1), 0),
        ("LEFTPADDING",   (0,0), (-1,-1), 0),
        ("RIGHTPADDING",  (0,0), (-1,-1), 0),
    ]))
    outer = Table([[inner]], colWidths=[CONTENT_W])
    style_cmds = [
        ("BACKGROUND",    (0,0), (-1,-1), bg_color),
        ("TOPPADDING",    (0,0), (-1,-1), 8),
        ("BOTTOMPADDING", (0,0), (-1,-1), 8),
        ("LEFTPADDING",   (0,0), (-1,-1), 10),
        ("RIGHTPADDING",  (0,0), (-1,-1), 10),
        ("ROUNDEDCORNERS", [radius]),
    ]
    if border_color:
        style_cmds += [
            ("BOX", (0,0), (-1,-1), 1, border_color),
        ]
    outer.setStyle(TableStyle(style_cmds))
    return outer

def two_col(left_items, right_items, ratio=(0.50, 0.50)):
    """Two-column layout."""
    lw = CONTENT_W * ratio[0] - 3
    rw = CONTENT_W * ratio[1] - 3
    left_tbl  = Table([[i] for i in left_items],  colWidths=[lw])
    right_tbl = Table([[i] for i in right_items], colWidths=[rw])
    for t in (left_tbl, right_tbl):
        t.setStyle(TableStyle([
            ("TOPPADDING",    (0,0), (-1,-1), 0),
            ("BOTTOMPADDING", (0,0), (-1,-1), 0),
            ("LEFTPADDING",   (0,0), (-1,-1), 0),
            ("RIGHTPADDING",  (0,0), (-1,-1), 0),
        ]))
    row = Table([[left_tbl, right_tbl]], colWidths=[lw+3, rw+3])
    row.setStyle(TableStyle([
        ("VALIGN", (0,0), (-1,-1), "TOP"),
        ("LEFTPADDING",   (0,0), (-1,-1), 0),
        ("RIGHTPADDING",  (0,0), (-1,-1), 0),
        ("TOPPADDING",    (0,0), (-1,-1), 0),
        ("BOTTOMPADDING", (0,0), (-1,-1), 0),
    ]))
    return row

def make_table(headers, rows, col_widths, hdr_color=NAVY, alt=True):
    data = [[Paragraph(h, S_TABLE_HDR) for h in headers]]
    for i, row in enumerate(rows):
        data.append([Paragraph(str(c), S_TABLE_CELL) for c in row])
    tbl = Table(data, colWidths=col_widths)
    cmds = [
        ("BACKGROUND",    (0,0), (-1,0), hdr_color),
        ("TOPPADDING",    (0,0), (-1,-1), 4),
        ("BOTTOMPADDING", (0,0), (-1,-1), 4),
        ("LEFTPADDING",   (0,0), (-1,-1), 5),
        ("RIGHTPADDING",  (0,0), (-1,-1), 5),
        ("GRID",          (0,0), (-1,-1), 0.4, HexColor("#d1d5db")),
        ("ROWBACKGROUNDS",(0,1), (-1,-1), [WHITE, GREY_LIGHT] if alt else [WHITE]),
        ("VALIGN",        (0,0), (-1,-1), "TOP"),
    ]
    tbl.setStyle(TableStyle(cmds))
    return tbl

def bullet(text, sub=False):
    s = S_SUBBULLET if sub else S_BULLET
    prefix = "   –  " if sub else "  •  "
    return Paragraph(f"{prefix}{text}", s)

def subbullet(text):
    return bullet(text, sub=True)

def sp(n=4):
    return Spacer(1, n)

def hr(color=HexColor("#e5e7eb"), thickness=0.5):
    return HRFlowable(width="100%", thickness=thickness, color=color, spaceAfter=4, spaceBefore=4)

def body(text):
    return Paragraph(text, S_BODY)

def sub(text):
    return Paragraph(text, S_SUBSEC)

def alert(text):
    return Paragraph(f"⚠  {text}", S_ALERT)

def key_point(text):
    return Paragraph(f"★  {text}", S_HIGHLIGHT)

# ── Cover page ───────────────────────────────────────────────────────────────
def cover_page():
    items = []

    # Title banner
    banner_data = [
        [Paragraph("HYPERTENSION", S_TITLE)],
        [Paragraph("Complete Study Guide for Exam Preparation", S_SUBTITLE)],
        [Spacer(1, 6)],
        [Paragraph("Definition  •  Etiopathogenesis  •  Clinical Features  •  Management", S_SUBTITLE)],
    ]
    banner = Table(banner_data, colWidths=[CONTENT_W])
    banner.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,-1), NAVY),
        ("TOPPADDING",    (0,0), (-1,-1), 10),
        ("BOTTOMPADDING", (0,0), (-1,-1), 10),
        ("LEFTPADDING",   (0,0), (-1,-1), 12),
        ("RIGHTPADDING",  (0,0), (-1,-1), 12),
        ("ROUNDEDCORNERS", [6]),
    ]))
    items.append(banner)
    items.append(sp(10))

    # TOC box
    toc_title = Paragraph("<b>TABLE OF CONTENTS</b>", style("tc",
        fontSize=11, textColor=NAVY, fontName="Helvetica-Bold",
        alignment=TA_CENTER, leading=16))
    toc_items = [
        ("1.", "Definition & Classification of Blood Pressure"),
        ("2.", "Etiology – Primary vs Secondary Hypertension"),
        ("3.", "Etiopathogenesis – Mechanisms & Risk Factors"),
        ("4.", "Diseases Associated with Hypertension"),
        ("5.", "Clinical Manifestations (Symptoms & Signs)"),
        ("6.", "Target-Organ Damage & Complications"),
        ("7.", "Non-Pharmacological Management"),
        ("8.", "Pharmacological Management – Drug Classes"),
        ("9.", "Drug Selection Guide & Special Situations"),
        ("10.", "Hypertensive Emergency vs Urgency"),
        ("11.", "High-Yield Exam Mnemonics & Quick Recalls"),
    ]
    toc_rows = [[Paragraph(f"<b>{n}</b>", S_TABLE_CELL_C),
                 Paragraph(t, S_TABLE_CELL)] for n, t in toc_items]
    toc_tbl = Table([[toc_title]] + toc_rows,
                    colWidths=[18*mm, CONTENT_W - 34*mm])
    toc_tbl.setStyle(TableStyle([
        ("SPAN",          (0,0), (-1,0)),
        ("BACKGROUND",    (0,0), (-1,0), LIGHT_BLUE),
        ("TOPPADDING",    (0,0), (-1,-1), 4),
        ("BOTTOMPADDING", (0,0), (-1,-1), 4),
        ("LEFTPADDING",   (0,0), (-1,-1), 6),
        ("RIGHTPADDING",  (0,0), (-1,-1), 6),
        ("ROWBACKGROUNDS",(0,1), (-1,-1), [WHITE, GREY_LIGHT]),
        ("GRID",          (0,0), (-1,-1), 0.3, HexColor("#d1d5db")),
        ("BOX",           (0,0), (-1,-1), 1,   NAVY),
        ("VALIGN",        (0,0), (-1,-1), "MIDDLE"),
    ]))
    items.append(toc_tbl)
    items.append(sp(10))

    # Key stats box
    stats = [
        Paragraph("<b>KEY EPIDEMIOLOGY FACTS</b>", style("sf",
            fontSize=9.5, textColor=TEAL, fontName="Helvetica-Bold",
            alignment=TA_CENTER, leading=14)),
        sp(4),
    ]
    stat_rows = [
        ["Global prevalence:", "~1.13 billion people affected (2015)"],
        ["Adult prevalence:", "30–40% worldwide; >60% in those aged >60 yrs"],
        ["Primary (Essential):", "~90% of all hypertension cases"],
        ["Secondary:", "~10% – identifiable treatable cause"],
        ["'Rule of halves':", "½ aware → ½ treated → ½ adequately controlled"],
        ["CVD risk:", "Doubles with every 20/10 mmHg rise above 115/75"],
    ]
    st = Table(stat_rows, colWidths=[52*mm, CONTENT_W - 68*mm])
    st.setStyle(TableStyle([
        ("FONTNAME",      (0,0), (0,-1), "Helvetica-Bold"),
        ("FONTSIZE",      (0,0), (-1,-1), 8.5),
        ("TEXTCOLOR",     (0,0), (0,-1), TEAL),
        ("TEXTCOLOR",     (1,0), (1,-1), GREY_DARK),
        ("TOPPADDING",    (0,0), (-1,-1), 3),
        ("BOTTOMPADDING", (0,0), (-1,-1), 3),
        ("ROWBACKGROUNDS",(0,0), (-1,-1), [TEAL_LIGHT, WHITE]),
        ("LEFTPADDING",   (0,0), (-1,-1), 6),
        ("GRID",          (0,0), (-1,-1), 0.3, HexColor("#99f6e4")),
    ]))
    stats.append(st)
    items.append(colored_box(stats, TEAL_LIGHT, TEAL))
    items.append(sp(8))

    # Disclaimer
    items.append(Paragraph(
        "<i>Based on: Park's Preventive Medicine | Katzung's Pharmacology 16e | Goldman-Cecil Medicine | Brenner & Rector's Kidney</i>",
        style("disc", fontSize=7.5, textColor=GREY_MID, alignment=TA_CENTER, leading=10)))

    return items

# ── Section 1: Definition & Classification ──────────────────────────────────
def section_definition():
    items = []
    items.append(section_header("1.  DEFINITION & CLASSIFICATION OF BLOOD PRESSURE", NAVY))
    items.append(sp(6))

    items.append(body(
        "<b>Hypertension</b> is defined as a sustained elevation of arterial blood pressure above a threshold "
        "that increases cardiovascular risk. The dividing line between normal and elevated BP is "
        "<b>operational</b>, not absolute – BP in a population follows a continuous bell-shaped curve "
        "(Pickering). Diagnosis requires the <b>average of ≥2 readings on ≥2 separate occasions</b>."))
    items.append(sp(4))

    items.append(sub("ESH / WHO Classification"))
    cls_data = [
        ["Category", "Systolic (mmHg)", "", "Diastolic (mmHg)"],
        ["Optimal",        "< 120",     "and",  "< 80"],
        ["Normal",         "120–129",   "and/or","80–84"],
        ["High Normal",    "130–139",   "and/or","85–89"],
        ["Grade 1 HTN ★",  "140–159",   "and/or","90–99"],
        ["Grade 2 HTN ★",  "160–179",   "and/or","100–109"],
        ["Grade 3 HTN ★",  "≥ 180",     "and/or","> 110"],
        ["Isolated Systolic HTN", "≥ 140", "and","< 90"],
    ]
    widths = [52*mm, 38*mm, 16*mm, 38*mm]
    data_rows = []
    hdr = [Paragraph(f"<b>{h}</b>", S_TABLE_HDR) for h in cls_data[0]]
    data_rows.append(hdr)
    for row in cls_data[1:]:
        is_htn = "★" in row[0]
        fg = RED if is_htn else GREY_DARK
        s = ParagraphStyle("tc2", parent=S_TABLE_CELL, textColor=fg,
                           fontName="Helvetica-Bold" if is_htn else "Helvetica")
        data_rows.append([Paragraph(str(c), s) for c in row])
    tbl = Table(data_rows, colWidths=widths)
    tbl.setStyle(TableStyle([
        ("BACKGROUND",    (0,0), (-1,0), NAVY),
        ("GRID",          (0,0), (-1,-1), 0.4, HexColor("#d1d5db")),
        ("ROWBACKGROUNDS",(0,1), (-1,-1), [WHITE, GREY_LIGHT]),
        ("TOPPADDING",    (0,0), (-1,-1), 4),
        ("BOTTOMPADDING", (0,0), (-1,-1), 4),
        ("LEFTPADDING",   (0,0), (-1,-1), 5),
        ("ALIGN",         (1,0), (3,-1), "CENTER"),
        ("VALIGN",        (0,0), (-1,-1), "MIDDLE"),
    ]))
    items.append(tbl)
    items.append(sp(4))

    items.append(sub("ACC/AHA 2017 (US Guidelines)"))
    acc_rows = [
        ["Elevated", "120–129 / < 80"],
        ["Stage I HTN", "130–139 / 80–89"],
        ["Stage II HTN", "≥ 140 / ≥ 90"],
    ]
    items.append(make_table(["Category","BP (mmHg)"], acc_rows,
                             [60*mm, CONTENT_W-66*mm], hdr_color=MED_BLUE))
    items.append(sp(4))

    items.append(key_point(
        "RULE: When systolic & diastolic fall in different categories → use the HIGHER category."))

    return items

# ── Section 2: Etiology ──────────────────────────────────────────────────────
def section_etiology():
    items = []
    items.append(section_header("2.  ETIOLOGY – PRIMARY vs SECONDARY HYPERTENSION", MED_BLUE))
    items.append(sp(6))

    left = [
        colored_box([
            Paragraph("<b>PRIMARY (ESSENTIAL) HTN</b>", style("ph",
                fontSize=9.5, textColor=MED_BLUE, fontName="Helvetica-Bold", leading=13)),
            sp(3),
            bullet("<b>~90%</b> of all cases"),
            bullet("No single identifiable cause"),
            bullet("Multifactorial – genetic + environmental"),
            bullet("Diagnosis of exclusion"),
            sp(3),
            Paragraph("<b>Risk factors:</b>", style("rf", fontSize=9, textColor=GREY_DARK,
                fontName="Helvetica-Bold", leading=12)),
            bullet("Age, family history, male sex"),
            bullet("Obesity (BMI > 30)"),
            bullet("High sodium / low potassium diet"),
            bullet("Alcohol excess"),
            bullet("Sedentary lifestyle"),
            bullet("Psychological stress"),
            bullet("Race (Black > White)"),
        ], LIGHT_BLUE, MED_BLUE),
    ]

    right_items_top = [
        colored_box([
            Paragraph("<b>SECONDARY HTN (~10%)</b>", style("sh",
                fontSize=9.5, textColor=RED, fontName="Helvetica-Bold", leading=13)),
            sp(3),
        ] + [bullet(t) for t in [
            "<b>Renal:</b> Chronic GN, pyelonephritis, PKD, RAS",
            "<b>Endocrine:</b> Pheochromocytoma, Conn syndrome (primary aldosteronism), Cushing syndrome, hypothyroidism",
            "<b>Cardiovascular:</b> Coarctation of the aorta",
            "<b>Drugs:</b> OCP, NSAIDs, steroids, stimulants",
            "<b>Pregnancy:</b> Pre-eclampsia / eclampsia",
        ]], RED_LIGHT, RED),
    ]
    right_items_top.append(sp(4))
    right_items_top.append(colored_box([
        Paragraph("<b>CLUES TO SECONDARY HTN</b>", style("cs",
            fontSize=8.5, textColor=ORANGE, fontName="Helvetica-Bold", leading=12)),
        sp(2),
        bullet("Age < 30 or sudden-onset HTN"),
        bullet("Resistant to ≥3 drugs"),
        bullet("Hypokalemia → primary aldosteronism"),
        bullet("Episodic HTN + sweating/palpitations → pheo"),
        bullet("Abdominal bruit → renal artery stenosis"),
    ], ORANGE_LIGHT, ORANGE))

    items.append(two_col(left, right_items_top, ratio=(0.48, 0.52)))
    return items

# ── Section 3: Etiopathogenesis ──────────────────────────────────────────────
def section_pathogenesis():
    items = []
    items.append(section_header("3.  ETIOPATHOGENESIS – KEY MECHANISMS", TEAL))
    items.append(sp(6))

    items.append(body(
        "In essential hypertension, elevated BP is caused by <b>multifactorial abnormalities</b>. "
        "The final common pathway is increased <b>peripheral vascular resistance (PVR)</b>, "
        "with cardiac output typically normal. Baroreceptors and the renal pressure-volume control "
        "system are 'reset' at a higher set-point."))
    items.append(sp(6))

    mechs = [
        ("RAAS Activation", TEAL, TEAL_LIGHT, [
            "↓ renal perfusion → juxtaglomerular cells release <b>Renin</b>",
            "Renin: Angiotensinogen → Angiotensin I",
            "ACE (lung): Ang I → <b>Angiotensin II</b>",
            "Ang II: (1) vasoconstriction ↑ PVR; (2) ↑ aldosterone → Na⁺/H₂O retention",
            "Also: intrarenal RAAS in PKD, CKD independently drives HTN",
        ]),
        ("Sympathetic Nervous System", MED_BLUE, LIGHT_BLUE, [
            "Increased SNS tone → arteriolar constriction → ↑ PVR",
            "Baroreceptors reset at higher set-point → blunted buffering",
            "Beta-adrenoceptor stimulation → ↑ renin secretion",
            "Stress → central sympathetic overdrive",
        ]),
        ("Renal Na⁺ Handling", NAVY, GREY_LIGHT, [
            "Impaired renal Na⁺ excretion → volume expansion → ↑ BP",
            "Salt-sensitive individuals: ↑ Na intake → proportional ↑ BP",
            "Pressure-natriuresis curve shifted rightward in HTN",
        ]),
        ("Endothelial Dysfunction", ORANGE, ORANGE_LIGHT, [
            "↓ Nitric oxide (NO) → impaired vasodilation",
            "↑ Endothelin-1 → vasoconstriction",
            "↑ Reactive oxygen species (ROS) → accelerates NO degradation",
            "Impaired endothelium-dependent vasorelaxation (demonstrated in ADPKD before HTN onset)",
        ]),
        ("Insulin Resistance / Metabolic", GREEN, GREEN_LIGHT, [
            "Hyperinsulinemia → SNS activation + renal Na⁺ retention",
            "Visceral adipocytes secrete IL-6, TNF-α, CRP → endothelial injury",
            "Strong association: obesity, MetS, Type 2 DM → HTN",
        ]),
        ("Genetic Factors", PURPLE, PURPLE_LIGHT, [
            "Heritability of essential HTN ~30%",
            "Polygenic: multiple loci, each with small effect",
            "Monogenic causes: Liddle syndrome, Gordon syndrome, glucocorticoid-remediable aldosteronism",
        ]),
    ]

    for title, hdr_col, bg_col, points in mechs:
        box_items = [
            Paragraph(f"<b>{title}</b>", style("mt",
                fontSize=9.5, textColor=hdr_col, fontName="Helvetica-Bold", leading=13)),
            sp(3),
        ] + [bullet(p) for p in points]
        items.append(colored_box(box_items, bg_col, hdr_col))
        items.append(sp(5))

    return items

# ── Section 4: Associated Diseases ───────────────────────────────────────────
def section_assoc_diseases():
    items = []
    items.append(section_header("4.  DISEASES ASSOCIATED WITH HYPERTENSION", RED))
    items.append(sp(6))

    items.append(body(
        "Hypertension is the 'silent killer' – usually <b>asymptomatic</b> until target-organ damage occurs. "
        "Sustained elevated BP damages vessels in the heart, brain, kidneys, and eyes. "
        "Global deaths attributable to systolic BP ≥140 mmHg: <b>~10 million/year</b>."))
    items.append(sp(5))

    disease_data = [
        ["IHD / CAD", "Atherosclerosis accelerated by HTN-induced endothelial injury and shear stress",
         "Angina, MI, sudden cardiac death", "~4.9 million deaths/yr"],
        ["Heart Failure", "LV pressure overload → LVH → diastolic/systolic dysfunction",
         "Dyspnea, orthopnea, PND, leg edema, S3 gallop", "Most common cause of HF in West"],
        ["Haemorrhagic Stroke", "Arteriolar rupture (Charcot-Bouchard aneurysms) → ICH",
         "Sudden severe headache, vomiting, focal deficits, coma", "~2 million deaths/yr"],
        ["Ischaemic Stroke / TIA", "Atherosclerosis of cerebral arteries, lacunar infarcts",
         "Hemiplegia, dysphasia, visual field defects", "~1.5 million deaths/yr"],
        ["Hypertensive Encephalopathy", "BP exceeds cerebral autoregulation → vasogenic oedema",
         "Severe headache, confusion, seizures, visual disturbance – NO focal signs (unlike stroke)",
         "PRES syndrome on MRI"],
        ["Aortic Dissection", "High pulse pressure → intimal tear",
         "Sudden tearing chest/back pain, pulse differentials, AR murmur", "Type A → surgery; Type B → medical"],
        ["CKD / Nephrosclerosis", "Arteriolar thickening → glomerulosclerosis → proteinuria",
         "Proteinuria, rising creatinine, oedema, nocturia, uraemia",
         "HTN ↔ CKD vicious cycle"],
        ["Hypertensive Retinopathy", "Arteriolar wall changes, haemorrhages, exudates",
         "Grade I-IV (see below); visual blurring in severe cases",
         "Grade IV = papilloedema = EMERGENCY"],
        ["Peripheral Arterial Disease", "Atherosclerosis of limb arteries – HTN is 2.5× risk (men), 3.9× (women)",
         "Intermittent claudication, rest pain, ulcers",
         "ABI < 0.9 diagnostic"],
    ]

    d_tbl = make_table(
        ["Disease", "Mechanism", "Clinical Features", "Key Fact"],
        disease_data,
        [38*mm, 48*mm, 52*mm, 40*mm],
        hdr_color=RED,
    )
    items.append(d_tbl)
    items.append(sp(6))

    # Retinopathy grading
    items.append(sub("Hypertensive Retinopathy – Keith-Wagener-Barker Grading"))
    ret_rows = [
        ["Grade I", "Mild arteriolar narrowing / increased light reflex ('silver wiring')", "Asymptomatic"],
        ["Grade II", "AV nicking (Gunn's sign); copper wiring", "Asymptomatic"],
        ["Grade III", "Flame haemorrhages, cotton-wool spots, hard exudates", "Possible visual blurring"],
        ["Grade IV ⚠", "Papilloedema (disc swelling) ± all Grade III features", "HYPERTENSIVE EMERGENCY"],
    ]
    r_tbl = make_table(
        ["Grade", "Fundus Findings", "Significance"],
        ret_rows,
        [22*mm, 90*mm, CONTENT_W - 118*mm],
        hdr_color=ORANGE,
    )
    items.append(r_tbl)

    return items

# ── Section 5: Clinical Manifestations ──────────────────────────────────────
def section_clinical():
    items = []
    items.append(section_header("5.  CLINICAL MANIFESTATIONS", MED_BLUE))
    items.append(sp(6))

    left = [
        colored_box([
            Paragraph("<b>UNCOMPLICATED HTN</b>", style("uh",
                fontSize=9.5, textColor=MED_BLUE, fontName="Helvetica-Bold", leading=13)),
            sp(3),
            Paragraph("Usually <b>ASYMPTOMATIC</b>", style("as",
                fontSize=9, textColor=RED, fontName="Helvetica-Bold",
                alignment=TA_CENTER, leading=13)),
            sp(3),
            Paragraph("<i>When symptoms occur:</i>", style("ws",
                fontSize=8.5, textColor=GREY_MID, fontName="Helvetica-Oblique", leading=12)),
            bullet("Morning occipital headache"),
            bullet("Epistaxis"),
            bullet("Dizziness / tinnitus"),
            bullet("Palpitations"),
            bullet("Visual disturbances (in severe HTN)"),
            sp(4),
            Paragraph("<i>Physical examination findings:</i>", style("pe",
                fontSize=8.5, textColor=GREY_MID, fontName="Helvetica-Oblique", leading=12)),
            bullet("Thickened / tortuous radial artery"),
            bullet("Accentuated A2 heart sound"),
            bullet("LV heave / LVH on ECG"),
            bullet("Retinal changes on fundoscopy"),
        ], LIGHT_BLUE, MED_BLUE),
    ]

    right = [
        colored_box([
            Paragraph("<b>WITH TARGET-ORGAN DAMAGE</b>", style("tod",
                fontSize=9.5, textColor=RED, fontName="Helvetica-Bold", leading=13)),
            sp(3),
            Paragraph("<b>Heart:</b>", style("h1", fontSize=9, textColor=NAVY,
                fontName="Helvetica-Bold", leading=12)),
            bullet("Exertional dyspnea, orthopnea"),
            bullet("S3 / S4 gallop, basal crepitations"),
            bullet("Angina / chest pain"),
            sp(2),
            Paragraph("<b>Brain:</b>", style("h2", fontSize=9, textColor=NAVY,
                fontName="Helvetica-Bold", leading=12)),
            bullet("Headache, confusion, seizures"),
            bullet("Focal neurological deficits (stroke)"),
            bullet("Obtundation (encephalopathy)"),
            sp(2),
            Paragraph("<b>Kidneys:</b>", style("h3", fontSize=9, textColor=NAVY,
                fontName="Helvetica-Bold", leading=12)),
            bullet("Proteinuria, haematuria"),
            bullet("Nocturia, oedema"),
            bullet("Uraemic symptoms (late)"),
            sp(2),
            Paragraph("<b>Eyes:</b>", style("h4", fontSize=9, textColor=NAVY,
                fontName="Helvetica-Bold", leading=12)),
            bullet("Blurred vision, visual loss"),
            bullet("Papilloedema (Grade IV)"),
        ], RED_LIGHT, RED),
    ]

    items.append(two_col(left, right))
    return items

# ── Section 6: Non-Pharmacological Management ────────────────────────────────
def section_nonpharm():
    items = []
    items.append(section_header("6.  NON-PHARMACOLOGICAL MANAGEMENT", GREEN))
    items.append(sp(6))

    items.append(body(
        "Lifestyle modifications are <b>mandatory for ALL patients</b> at every stage of hypertension "
        "and should be maintained alongside drug therapy. They can lower BP by <b>5–20 mmHg each</b> "
        "and may normalize mild hypertension without drugs."))
    items.append(sp(5))

    lifestyle_rows = [
        ["Weight Reduction", "Achieve BMI 18.5–24.9 kg/m²; reduce waist circumference",
         "5–20 mmHg per 10 kg lost"],
        ["DASH Diet", "Rich in fruits, vegetables, low-fat dairy; ↓ saturated fat & red meat",
         "8–14 mmHg"],
        ["Sodium Restriction", "< 2.4 g Na/day (< 6 g NaCl); avoid processed foods",
         "2–8 mmHg"],
        ["Physical Activity", "≥ 30 min moderate aerobic exercise on most days (brisk walking, swimming)",
         "4–9 mmHg"],
        ["Alcohol Moderation", "≤ 2 drinks/day (men); ≤ 1 drink/day (women)",
         "2–4 mmHg"],
        ["Smoking Cessation", "Complete cessation – lowers CVD risk (not BP directly)",
         "↓ CVD risk"],
        ["Increase Potassium", "Dietary potassium ≥ 3,500 mg/day (bananas, sweet potatoes, spinach)",
         "2–4 mmHg"],
        ["Stress Reduction", "Relaxation techniques, yoga, cognitive-behavioural therapy",
         "Variable (2–5 mmHg)"],
    ]
    items.append(make_table(
        ["Intervention", "How / Target", "Expected BP Reduction"],
        lifestyle_rows,
        [42*mm, 90*mm, CONTENT_W - 138*mm],
        hdr_color=GREEN,
    ))
    items.append(sp(5))

    items.append(key_point(
        "DASH = Dietary Approaches to Stop Hypertension – the most evidence-based dietary intervention. "
        "Salt restriction potentiates the effect of ALL antihypertensive drugs."))

    return items

# ── Section 7: Pharmacological Management ────────────────────────────────────
def section_pharm():
    items = []
    items.append(section_header("7.  PHARMACOLOGICAL MANAGEMENT", NAVY))
    items.append(sp(6))

    # When to start
    items.append(sub("When to Initiate Drug Therapy"))
    start_rows = [
        ["Grade 1 / Stage I HTN\n(140–159/90–99)", "If: high CV risk, organ damage, DM, CKD OR after 3–6 months lifestyle trial failure"],
        ["Grade 2 / Stage II HTN\n(160–179/100–109)", "Start drug therapy promptly alongside lifestyle changes"],
        ["Grade 3 HTN (≥180/110)", "Start drug therapy immediately; 2-drug combination from outset"],
        ["BP target (most patients)", "< 130/80 mmHg (ACC/AHA); < 140/90 (ESH/WHO)"],
        ["BP target (high-risk / SPRINT)", "< 120 mmHg systolic (standard protocol measurement)"],
    ]
    items.append(make_table(
        ["Scenario", "Action"],
        start_rows,
        [58*mm, CONTENT_W - 64*mm],
        hdr_color=MED_BLUE,
    ))
    items.append(sp(6))

    # First-line drugs
    items.append(sub("First-Line Drug Classes"))
    items.append(body(
        "Guidelines recommend initiating therapy with <b>TWO OR MORE</b> of the three primary classes: "
        "<b>CCBs</b>, <b>ACE-I or ARBs</b>, and <b>Thiazide/Thiazide-like Diuretics</b>."))
    items.append(sp(5))

    drug_classes = [
        {
            "name": "A – ACE INHIBITORS",
            "color": TEAL,
            "bg": TEAL_LIGHT,
            "agents": "Ramipril, Enalapril, Lisinopril, Perindopril, Captopril",
            "moa": "Inhibit ACE → ↓ Ang II (vasoconstriction) + ↓ bradykinin degradation → ↑ NO/prostacyclin vasodilation",
            "indications": "DM with CKD/proteinuria ★, Heart failure (HFrEF) ★, Post-MI ★, LV dysfunction",
            "side_effects": "Dry cough (10–15%, bradykinin-mediated), Angioedema (rare), Hyperkalaemia, AKI in bilateral RAS",
            "contraind": "Pregnancy, bilateral RAS, hyperkalaemia; AVOID dual RAAS blockade",
        },
        {
            "name": "B – ANGIOTENSIN RECEPTOR BLOCKERS (ARBs)",
            "color": MED_BLUE,
            "bg": LIGHT_BLUE,
            "agents": "Losartan, Valsartan, Candesartan, Irbesartan, Telmisartan, Olmesartan",
            "moa": "Block AT1 receptors → ↓ Ang II effects. Allow preferential AT2 binding (vasodilation). NO bradykinin effect → no cough",
            "indications": "Same as ACE-I; use when ACE-I causes cough ★. DM nephropathy, HF, post-MI",
            "side_effects": "Hyperkalaemia, AKI – similar to ACE-I but NO cough. Angioedema (rare)",
            "contraind": "Pregnancy; AVOID with ACE-I (dual blockade)",
        },
        {
            "name": "C – CALCIUM CHANNEL BLOCKERS (CCBs)",
            "color": GREEN,
            "bg": GREEN_LIGHT,
            "agents": "Amlodipine (DHP, preferred) ★; Nifedipine; Diltiazem / Verapamil (non-DHP)",
            "moa": "Block voltage-gated L-type Ca²⁺ channels in vascular smooth muscle → arteriolar vasodilation → ↓ PVR",
            "indications": "Most patients ★; Most effective for STROKE prevention ★; Angina; Elderly; Black patients; Effect independent of Na intake & NSAIDs",
            "side_effects": "DHP: ankle oedema (dose-dependent), flushing, reflex tachycardia. Verapamil: constipation, ↓ AV conduction",
            "contraind": "Non-DHP + beta-blocker = additive bradycardia/heart block. Short-acting nifedipine NOT for chronic use",
        },
        {
            "name": "D – THIAZIDE / THIAZIDE-LIKE DIURETICS",
            "color": ORANGE,
            "bg": ORANGE_LIGHT,
            "agents": "Chlorthalidone ★ (preferred), Hydrochlorothiazide 25–50 mg, Indapamide 1.25–2.5 mg",
            "moa": "Inhibit NaCl reabsorption in DCT → initial volume depletion; long-term: ↓ peripheral vascular resistance",
            "indications": "First-line in most patients ★; Elderly / isolated systolic HTN; Heart failure; Black patients",
            "side_effects": "Hypokalaemia ★, Hyponatraemia, Hyperuricaemia (gout), Glucose intolerance, Dyslipidaemia",
            "contraind": "Gout (caution); Hypokalaemia; Avoid if eGFR < 30 (thiazides lose efficacy)",
        },
    ]

    for d in drug_classes:
        box_content = [
            Paragraph(f"<b>{d['name']}</b>", style("dn",
                fontSize=10, textColor=d["color"], fontName="Helvetica-Bold", leading=14)),
            sp(3),
        ]
        inner_rows = [
            ["Agents:", d["agents"]],
            ["Mechanism:", d["moa"]],
            ["Key Indications:", d["indications"]],
            ["Side Effects:", d["side_effects"]],
            ["Contraindications:", d["contraind"]],
        ]
        inner_tbl = Table(inner_rows, colWidths=[32*mm, CONTENT_W - 52*mm])
        inner_tbl.setStyle(TableStyle([
            ("FONTNAME",      (0,0), (0,-1), "Helvetica-Bold"),
            ("FONTSIZE",      (0,0), (-1,-1), 8.5),
            ("TEXTCOLOR",     (0,0), (0,-1), d["color"]),
            ("TEXTCOLOR",     (1,0), (1,-1), GREY_DARK),
            ("TOPPADDING",    (0,0), (-1,-1), 3),
            ("BOTTOMPADDING", (0,0), (-1,-1), 3),
            ("VALIGN",        (0,0), (-1,-1), "TOP"),
            ("ROWBACKGROUNDS",(0,0), (-1,-1), [d["bg"], WHITE]),
        ]))
        box_content.append(inner_tbl)
        items.append(colored_box(box_content, d["bg"], d["color"]))
        items.append(sp(6))

    return items

# ── Section 8: Additional Drug Classes ──────────────────────────────────────
def section_extra_drugs():
    items = []
    items.append(section_header("8.  ADDITIONAL ANTIHYPERTENSIVE DRUG CLASSES", PURPLE))
    items.append(sp(6))

    extra_rows = [
        ["Beta-Blockers\n(β-blockers)",
         "Metoprolol, Atenolol, Bisoprolol (β1-selective); Carvedilol, Labetalol (α+β)",
         "Block β1 → ↓ HR, ↓ CO; inhibit renin secretion",
         "Post-MI ★, HFrEF ★, Angina ★, Tachyarrhythmias. Labetalol/Hydralazine in PREGNANCY ★",
         "NOT first-line for uncomplicated HTN (less stroke protection). Fatigue, bradycardia, AV block, bronchoconstriction, impotence, masks hypoglycaemia"],
        ["Alpha-1 Blockers",
         "Prazosin, Terazosin, Doxazosin",
         "Block α1 in arterioles/venules → ↓ PVR. Dilation of resistance & capacitance vessels",
         "HTN + BPH in men ★ (dual benefit); Phaeochromocytoma (phenoxybenzamine)",
         "First-dose orthostatic hypotension ★ (give at bedtime, start low); Salt/water retention without diuretic"],
        ["Central Sympatholytics",
         "Clonidine (α2-agonist), Methyldopa, Moxonidine",
         "↓ Central sympathetic outflow → ↓ PVR and HR",
         "Methyldopa = DOC in PREGNANCY ★. Clonidine in resistant HTN",
         "Clonidine: rebound HTN on abrupt withdrawal ★. Methyldopa: hepatotoxicity, haemolytic anaemia"],
        ["MRAs (Aldosterone\nAntagonists)",
         "Spironolactone, Eplerenone",
         "Block aldosterone receptors in collecting duct → natriuresis",
         "Resistant HTN (4th agent) ★, Primary aldosteronism, HFrEF",
         "Hyperkalaemia ★, Gynaecomastia (spironolactone). Avoid if eGFR < 30"],
        ["Direct Vasodilators",
         "Hydralazine, Minoxidil",
         "Direct arteriolar smooth muscle relaxation",
         "Hydralazine: HF, PREGNANCY. Minoxidil: refractory HTN",
         "Reflex tachycardia + fluid retention – ALWAYS combine with beta-blocker + diuretic. Minoxidil: hypertrichosis"],
        ["Direct Renin\nInhibitor",
         "Aliskiren",
         "Blocks conversion of pro-renin → renin (1st step RAAS)",
         "Alternative if ACE-I/ARB not tolerated",
         "Avoid with ACE-I or ARB (dual RAAS blockade). Contraindicated in pregnancy"],
    ]

    items.append(make_table(
        ["Drug Class", "Agents", "Mechanism", "Indications ★", "Side Effects / Notes"],
        extra_rows,
        [30*mm, 38*mm, 38*mm, 42*mm, CONTENT_W - 154*mm],
        hdr_color=PURPLE,
    ))
    return items

# ── Section 9: Drug Selection Guide ─────────────────────────────────────────
def section_selection():
    items = []
    items.append(section_header("9.  DRUG SELECTION GUIDE & COMBINATION THERAPY", TEAL))
    items.append(sp(6))

    items.append(sub("Compelling Indications – Preferred Drugs"))
    comp_rows = [
        ["Heart Failure (HFrEF)", "ACE-I or ARB + Beta-blocker (carvedilol/bisoprolol) + Diuretic + MRA (spironolactone)"],
        ["Post-MI / ACS", "ACE-I or ARB + Beta-blocker"],
        ["Angina Pectoris", "Beta-blocker or CCB (non-DHP: diltiazem/verapamil)"],
        ["DM / CKD with Proteinuria", "ACE-I or ARB ★ (slow CKD progression, reduce intraglomerular pressure)"],
        ["Isolated Systolic HTN (Elderly)", "Thiazide diuretic or CCB (amlodipine)"],
        ["PREGNANCY ★", "Methyldopa ★, Labetalol, Hydralazine, Nifedipine (AVOID ACE-I/ARB/Aliskiren)"],
        ["BPH + HTN (Men)", "Doxazosin (α1-blocker) – dual benefit"],
        ["Black Patients", "CCB + Thiazide (respond less to ACE-I/beta-blocker monotherapy)"],
        ["Resistant HTN", "Add Spironolactone (MRA) as 4th agent ★"],
        ["Tachycardia / Post-operative HTN", "IV Esmolol (short-acting β1-blocker)"],
        ["Phaeochromocytoma (pre-op)", "Alpha-blocker first ★ (phenoxybenzamine), then add beta-blocker"],
        ["Aortic Dissection (acute)", "IV Labetalol + Nitroprusside / Nicardipine; target SBP < 120 rapidly"],
    ]
    items.append(make_table(
        ["Condition", "Preferred Drug(s)"],
        comp_rows,
        [60*mm, CONTENT_W - 66*mm],
        hdr_color=TEAL,
    ))
    items.append(sp(6))

    items.append(sub("Combination Therapy Strategies"))
    combo_rows = [
        ["2-drug", "ACE-I/ARB + CCB (e.g., ramipril + amlodipine) – most preferred"],
        ["2-drug", "ACE-I/ARB + Thiazide diuretic – effective; especially in heart failure"],
        ["2-drug", "CCB + Thiazide diuretic – effective in elderly, Black patients"],
        ["3-drug", "ACE-I/ARB + CCB + Thiazide – standard triple therapy"],
        ["4-drug", "Add beta-blocker or clonidine or MRA"],
        ["Resistant HTN", "Add spironolactone (best evidence as 4th agent)"],
        ["AVOID ★", "ACE-I + ARB, or ACE-I + Aliskiren – dual RAAS blockade → ↑ AKI, hyperkalaemia"],
    ]
    items.append(make_table(
        ["Type", "Combination"],
        combo_rows,
        [28*mm, CONTENT_W - 34*mm],
        hdr_color=MED_BLUE,
    ))
    items.append(sp(5))
    items.append(alert(
        "NEVER combine two RAAS inhibitors (ACE-I + ARB, ACE-I + aliskiren) – significantly increased risk of "
        "acute kidney injury, hyperkalaemia, and hypotension."))

    return items

# ── Section 10: HTN Emergency ────────────────────────────────────────────────
def section_emergency():
    items = []
    items.append(section_header("10.  HYPERTENSIVE EMERGENCY vs URGENCY", RED))
    items.append(sp(6))

    left = [
        colored_box([
            Paragraph("<b>HYPERTENSIVE URGENCY</b>", style("hu",
                fontSize=9.5, textColor=ORANGE, fontName="Helvetica-Bold", leading=13)),
            sp(3),
            bullet("BP ≥ 180/110 mmHg"),
            bullet("<b>NO new / worsening target-organ injury</b>"),
            bullet("Often asymptomatic or mild symptoms"),
            sp(3),
            Paragraph("<b>Management:</b>", style("hum",
                fontSize=9, textColor=GREY_DARK, fontName="Helvetica-Bold", leading=12)),
            bullet("Restart/optimise oral medications"),
            bullet("Oral agents: labetalol, clonidine, captopril, amlodipine"),
            bullet("Outpatient follow-up in 24–48 hrs"),
            bullet("Avoid rapid IV reduction (risk of ischaemia)"),
        ], ORANGE_LIGHT, ORANGE),
    ]

    right = [
        colored_box([
            Paragraph("<b>HYPERTENSIVE EMERGENCY</b>", style("he",
                fontSize=9.5, textColor=RED, fontName="Helvetica-Bold", leading=13)),
            sp(3),
            bullet("BP ≥ 180/110 mmHg"),
            bullet("<b>WITH new/worsening target-organ damage</b>"),
            sp(2),
            Paragraph("<i>Common emergencies:</i>", style("ce",
                fontSize=8.5, textColor=GREY_MID, fontName="Helvetica-Oblique", leading=12)),
            bullet("Hypertensive encephalopathy / PRES"),
            bullet("Acute HF / pulmonary oedema"),
            bullet("ACS / acute MI"),
            bullet("Aortic dissection"),
            bullet("Eclampsia"),
            bullet("Haemorrhagic / ischaemic stroke"),
            sp(3),
            Paragraph("<b>Management:</b>", style("hem",
                fontSize=9, textColor=GREY_DARK, fontName="Helvetica-Bold", leading=12)),
            bullet("ICU admission + IV antihypertensives"),
            bullet("Reduce BP by <b>10–15%</b> in 1st 1–2 hrs"),
            bullet("Then 10–15% over next 12–24 hrs"),
            bullet("<b>EXCEPTION:</b> Aortic dissection & pulmonary oedema → rapid reduction"),
        ], RED_LIGHT, RED),
    ]
    items.append(two_col(left, right))
    items.append(sp(6))

    items.append(sub("Intravenous Drugs for Hypertensive Emergency"))
    iv_rows = [
        ["Nicardipine", "CCB (DHP)", "0.5–15 mcg/kg/min IV", "Most emergencies; outside ICU; safe in stroke"],
        ["Clevidipine", "CCB (DHP)", "1–32 mg/hr IV", "Perioperative HTN; rapid, titratable"],
        ["Labetalol", "α+β blocker", "20–80 mg IV bolus or 0.5–2 mg/min infusion", "Aortic dissection, post-op, pregnancy"],
        ["Esmolol", "β1-blocker (short-acting)", "0.5 mg/kg load → 50–300 mcg/kg/min", "Peri-op HTN with tachycardia; short half-life"],
        ["Sodium Nitroprusside", "Arterial + venous dilator", "0.25–10 mcg/kg/min IV", "Most emergencies; monitor cyanide toxicity"],
        ["Fenoldopam", "Dopamine D1 agonist", "0.1–1.6 mcg/kg/min IV", "Renal impairment (natriuretic effect)"],
        ["Hydralazine", "Direct vasodilator", "10–20 mg IV q4–6h", "Pre-eclampsia / eclampsia ★"],
        ["Enalaprilat", "ACE-I (IV)", "1.25–5 mg IV q6h", "Hypertensive emergency with high-renin states"],
    ]
    items.append(make_table(
        ["Drug", "Class", "Dose", "Use / Notes"],
        iv_rows,
        [30*mm, 35*mm, 50*mm, CONTENT_W - 121*mm],
        hdr_color=RED,
    ))

    return items

# ── Section 11: Mnemonics & Quick Recall ─────────────────────────────────────
def section_mnemonics():
    items = []
    items.append(section_header("11.  HIGH-YIELD EXAM MNEMONICS & QUICK RECALLS", PURPLE))
    items.append(sp(6))

    mnemonics = [
        ("ABCD – First-Line Antihypertensives",
         "A = ACE inhibitors / ARBs\nB = Beta-blockers (not first-line alone)\nC = Calcium channel blockers\nD = Diuretics (thiazide)",
         PURPLE, PURPLE_LIGHT),
        ("RAAS Chain – Remember This Sequence",
         "Angiotensinogen → (Renin) → Ang I → (ACE) → Ang II → Vasoconstriction + Aldosterone → Na⁺/H₂O retention → ↑ BP",
         TEAL, TEAL_LIGHT),
        ("Secondary HTN Causes – CHAPS",
         "C = Coarctation of aorta\nH = Hyperaldosteronism (Conn syndrome)\nA = Adrenal (Phaeochromocytoma, Cushing)\nP = Parenchymal renal disease / RAS\nS = Steroid drugs / OCP",
         ORANGE, ORANGE_LIGHT),
        ("Drug + Side Effect High-Yield Pairs",
         "ACE-I → DRY COUGH ★\nACE-I / ARB → Hyperkalaemia, Angioedema\nThiazide → Hypokalaemia, Hyperuricaemia, Glucose intolerance\nCCB (DHP) → Ankle oedema, Flushing\nVerapamil → CONSTIPATION, AV block\nClonidine → Rebound HTN on sudden withdrawal\nMinoxidil → Hypertrichosis, fluid retention\nAlpha-blockers → First-dose hypotension",
         RED, RED_LIGHT),
        ("Pregnancy – Safe Antihypertensives (MAN)",
         "M = Methyldopa (DOC)\nA = Amlodipine (CCB)\nN = Nifedipine, labetalol, hydralazine\n✗ AVOID: ACE-I, ARBs, Aliskiren (teratogenic)",
         GREEN, GREEN_LIGHT),
        ("Resistant HTN Definition",
         "BP ≥ 130/80 mmHg despite ≥ 3 antihypertensives (one being a diuretic) at optimal doses\n"
         "OR controlled on ≥ 4 drugs.\n"
         "Add SPIRONOLACTONE as 4th agent (best evidence).",
         MED_BLUE, LIGHT_BLUE),
        ("Target BP Quick Reference",
         "General: < 130/80 mmHg\nHigh-risk (SPRINT): < 120 mmHg systolic\nDiabetes: < 130/80 mmHg\nElderly (≥80 yrs): < 150/90 (tolerated); intensive if tolerating well",
         NAVY, GREY_LIGHT),
        ("HTN + Comorbidity → Best Drug",
         "HTN + DM + proteinuria → ACE-I / ARB ★\nHTN + HF → ACE-I/ARB + beta-blocker + MRA + diuretic\nHTN + Angina → Beta-blocker or CCB\nHTN + BPH → Doxazosin (alpha-blocker)\nHTN + Black patient → CCB + Thiazide (not ACE-I alone)\nHTN + Gout → AVOID thiazides → use amlodipine/ACE-I",
         TEAL, TEAL_LIGHT),
    ]

    for title, content, fg, bg in mnemonics:
        mbox = [
            Paragraph(f"<b>{title}</b>", style("mt2",
                fontSize=9.5, textColor=fg, fontName="Helvetica-Bold", leading=14)),
            sp(3),
        ]
        for line in content.split("\n"):
            if line.strip():
                mbox.append(Paragraph(f"  {line}", style("ml",
                    fontSize=9, textColor=GREY_DARK, fontName="Helvetica",
                    leading=13, leftIndent=8)))
        items.append(colored_box(mbox, bg, fg))
        items.append(sp(5))

    return items

# ── Page header / footer ─────────────────────────────────────────────────────
def on_page(canvas, doc):
    canvas.saveState()
    W_p, H_p = A4
    # Header bar
    canvas.setFillColor(NAVY)
    canvas.rect(0, H_p - 14*mm, W_p, 14*mm, fill=1, stroke=0)
    canvas.setFillColor(WHITE)
    canvas.setFont("Helvetica-Bold", 9)
    canvas.drawString(18*mm, H_p - 9*mm, "HYPERTENSION  |  Complete Study Guide")
    canvas.setFont("Helvetica", 8)
    canvas.drawRightString(W_p - 18*mm, H_p - 9*mm, "Orris Medical AI  •  2026")
    # Footer
    canvas.setFillColor(GREY_LIGHT)
    canvas.rect(0, 0, W_p, 10*mm, fill=1, stroke=0)
    canvas.setFillColor(GREY_MID)
    canvas.setFont("Helvetica", 7.5)
    canvas.drawString(18*mm, 3.5*mm,
        "Sources: Park's Preventive Medicine | Katzung's Pharmacology 16e | Goldman-Cecil Medicine | Brenner & Rector's Kidney")
    canvas.setFont("Helvetica-Bold", 8)
    canvas.drawRightString(W_p - 18*mm, 3.5*mm, f"Page {doc.page}")
    canvas.restoreState()

# ── Assemble document ────────────────────────────────────────────────────────
story = []

# Cover
story.extend(cover_page())
story.append(PageBreak())

# Sections
for fn in [
    section_definition,
    section_etiology,
    section_pathogenesis,
    section_assoc_diseases,
    section_clinical,
    section_nonpharm,
    section_pharm,
    section_extra_drugs,
    section_selection,
    section_emergency,
    section_mnemonics,
]:
    story.extend(fn())
    story.append(sp(10))
    story.append(hr(GREY_MID, 0.8))
    story.append(sp(6))

doc.build(story, onFirstPage=on_page, onLaterPages=on_page)
print(f"PDF created: {OUT}")