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, Image,
                                 Table, TableStyle, PageBreak, HRFlowable,
                                 KeepTogether)
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY
from reportlab.pdfgen import canvas
from reportlab.platypus import BaseDocTemplate, Frame, PageTemplate
import os

OUTPUT = "/home/daytona/workspace/anatomy-revision/Anatomy_Exam_Revision_Guide.pdf"
IMG_DIR = "/home/daytona/workspace/anatomy-revision/"

W, H = A4

# ── colour palette ──────────────────────────────────────────────────────────
C_NAVY   = colors.HexColor("#1a2e4a")
C_BLUE   = colors.HexColor("#2563eb")
C_TEAL   = colors.HexColor("#0d9488")
C_RED    = colors.HexColor("#dc2626")
C_ORANGE = colors.HexColor("#ea580c")
C_PURPLE = colors.HexColor("#7c3aed")
C_GREEN  = colors.HexColor("#16a34a")
C_GOLD   = colors.HexColor("#d97706")
C_LIGHT  = colors.HexColor("#f0f4ff")
C_LBLUE  = colors.HexColor("#dbeafe")
C_LTEAL  = colors.HexColor("#ccfbf1")
C_LRED   = colors.HexColor("#fee2e2")
C_LPUR   = colors.HexColor("#ede9fe")
C_LGOLD  = colors.HexColor("#fef3c7")
C_LGREY  = colors.HexColor("#f8fafc")
C_WHITE  = colors.white

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

def S(name, **kw):
    return ParagraphStyle(name, **kw)

cover_title = S("CoverTitle", fontSize=34, leading=42, textColor=C_WHITE,
                alignment=TA_CENTER, fontName="Helvetica-Bold")
cover_sub   = S("CoverSub",   fontSize=16, leading=22, textColor=colors.HexColor("#bfdbfe"),
                alignment=TA_CENTER, fontName="Helvetica")
cover_date  = S("CoverDate",  fontSize=12, leading=18, textColor=colors.HexColor("#93c5fd"),
                alignment=TA_CENTER, fontName="Helvetica-Oblique")

ch_title    = S("ChTitle",  fontSize=22, leading=28, textColor=C_WHITE,
                alignment=TA_LEFT, fontName="Helvetica-Bold",
                leftIndent=10, spaceAfter=4)
sec_title   = S("SecTitle", fontSize=14, leading=20, textColor=C_NAVY,
                fontName="Helvetica-Bold", spaceBefore=12, spaceAfter=4)
sub_title   = S("SubTitle", fontSize=12, leading=17, textColor=C_BLUE,
                fontName="Helvetica-Bold", spaceBefore=8, spaceAfter=3)
body        = S("Body",     fontSize=10, leading=15, textColor=colors.HexColor("#1e293b"),
                fontName="Helvetica", alignment=TA_JUSTIFY, spaceAfter=4)
bullet      = S("Bullet",   fontSize=10, leading=15, textColor=colors.HexColor("#1e293b"),
                fontName="Helvetica", leftIndent=14, bulletIndent=4,
                bulletText=u"\u2022", spaceAfter=2)
key_point   = S("KeyPoint", fontSize=10, leading=15, textColor=C_NAVY,
                fontName="Helvetica-Bold", leftIndent=14, spaceAfter=2)
caption     = S("Caption",  fontSize=9,  leading=13, textColor=colors.HexColor("#475569"),
                fontName="Helvetica-Oblique", alignment=TA_CENTER, spaceAfter=6)
tbl_hdr     = S("TblHdr",   fontSize=10, leading=14, textColor=C_WHITE,
                fontName="Helvetica-Bold", alignment=TA_CENTER)
tbl_cell    = S("TblCell",  fontSize=9,  leading=13, textColor=colors.HexColor("#1e293b"),
                fontName="Helvetica")

# ── helpers ──────────────────────────────────────────────────────────────────
def chapter_header(title, color=C_NAVY, number=""):
    """Returns a coloured chapter header block."""
    data = [[Paragraph(f"{number}  {title}", ch_title)]]
    t = Table(data, colWidths=[W - 4*cm])
    t.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,-1), color),
        ("ROUNDEDCORNERS", [8]),
        ("TOPPADDING",    (0,0),(-1,-1), 10),
        ("BOTTOMPADDING", (0,0),(-1,-1), 10),
        ("LEFTPADDING",   (0,0),(-1,-1), 16),
    ]))
    return t

def info_box(title, items, bg=C_LBLUE, title_color=C_BLUE):
    """Coloured info box with bullet list."""
    rows = [[Paragraph(title, S("IB_T", fontSize=11, fontName="Helvetica-Bold",
                                textColor=title_color))]]
    for it in items:
        rows.append([Paragraph(f"\u2022  {it}", S("IB_B", fontSize=9.5,
                                fontName="Helvetica", textColor=colors.HexColor("#1e293b"),
                                leading=14))])
    t = Table(rows, colWidths=[W - 4*cm])
    t.setStyle(TableStyle([
        ("BACKGROUND",    (0,0), (-1,-1), bg),
        ("TOPPADDING",    (0,0), (-1,-1), 5),
        ("BOTTOMPADDING", (0,0), (-1,-1), 4),
        ("LEFTPADDING",   (0,0), (-1,-1), 12),
        ("RIGHTPADDING",  (0,0), (-1,-1), 8),
        ("LINEBELOW",     (0,0), (-1,0), 0.8, title_color),
    ]))
    return t

def two_col_table(headers, rows, col_colors=None):
    col_colors = col_colors or [C_NAVY, C_TEAL]
    hdr_row = [Paragraph(h, tbl_hdr) for h in headers]
    data = [hdr_row] + [[Paragraph(str(c), tbl_cell) for c in row] for row in rows]
    n = len(headers)
    cw = [(W - 4*cm) / n] * n
    t = Table(data, colWidths=cw, repeatRows=1)
    style = [
        ("BACKGROUND",    (0,0), (-1,0), C_NAVY),
        ("ROWBACKGROUNDS",(0,1), (-1,-1), [C_LGREY, C_WHITE]),
        ("GRID",          (0,0), (-1,-1), 0.4, colors.HexColor("#cbd5e1")),
        ("TOPPADDING",    (0,0), (-1,-1), 5),
        ("BOTTOMPADDING", (0,0), (-1,-1), 5),
        ("LEFTPADDING",   (0,0), (-1,-1), 8),
    ]
    for i, c in enumerate(col_colors):
        if i == 0:
            style.append(("BACKGROUND", (i,0), (i,0), c))
    t.setStyle(TableStyle(style))
    return t

def img(fname, w=None, caption_text=""):
    path = IMG_DIR + fname
    if not os.path.exists(path):
        return Spacer(1, 0.5*cm)
    iw = w or (W - 4*cm)
    from PIL import Image as PILImage
    with PILImage.open(path) as pil:
        orig_w, orig_h = pil.size
    ratio = orig_h / orig_w
    ih = iw * ratio
    # cap height to keep on one page
    max_h = 18*cm
    if ih > max_h:
        ih = max_h
        iw = ih / ratio
    elems = [Image(path, width=iw, height=ih)]
    if caption_text:
        elems.append(Paragraph(caption_text, caption))
    return elems

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

# ── page numbering ────────────────────────────────────────────────────────────
class NumberedCanvas(canvas.Canvas):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self._saved_page_states = []

    def showPage(self):
        self._saved_page_states.append(dict(self.__dict__))
        self._startPage()

    def save(self):
        num_pages = len(self._saved_page_states)
        for state in self._saved_page_states:
            self.__dict__.update(state)
            self.draw_page_number(num_pages)
            super().showPage()
        super().save()

    def draw_page_number(self, page_count):
        pg = self._pageNumber
        self.saveState()
        self.setFont("Helvetica", 8)
        self.setFillColor(colors.HexColor("#94a3b8"))
        self.drawRightString(W - 2*cm, 1.2*cm, f"Page {pg} of {page_count}")
        self.drawString(2*cm, 1.2*cm, "Anatomy Exam Revision Guide  |  June 2026")
        self.restoreState()

# ── document ──────────────────────────────────────────────────────────────────
doc = SimpleDocTemplate(
    OUTPUT, pagesize=A4,
    leftMargin=2*cm, rightMargin=2*cm,
    topMargin=2.2*cm, bottomMargin=2.2*cm,
    title="Anatomy Exam Revision Guide",
    author="Orris AI"
)

story = []

# ══════════════════════════════════════════════════════════════════════════════
# COVER PAGE
# ══════════════════════════════════════════════════════════════════════════════
def cover_page(canvas_obj, doc_obj):
    canvas_obj.saveState()
    # gradient-like background
    canvas_obj.setFillColor(C_NAVY)
    canvas_obj.rect(0, 0, W, H, fill=1, stroke=0)
    canvas_obj.setFillColor(C_BLUE)
    canvas_obj.rect(0, H*0.55, W, H*0.45, fill=1, stroke=0)
    # decorative strip
    canvas_obj.setFillColor(C_TEAL)
    canvas_obj.rect(0, H*0.48, W, 0.6*cm, fill=1, stroke=0)
    canvas_obj.restoreState()

story.append(Spacer(1, 3.5*cm))
story.append(Paragraph("ANATOMY", cover_title))
story.append(Paragraph("Exam Revision Guide", cover_title))
story.append(Spacer(1, 0.6*cm))
story.append(Paragraph("Complete Notes with HD Labelled Diagrams", cover_sub))
story.append(Spacer(1, 0.4*cm))
story.append(Paragraph("Pelvis & Pelvic Organs  •  Lower Extremity  •  Vertebral Column", cover_sub))
story.append(Paragraph("Head & Neck  •  Neuroanatomy", cover_sub))
story.append(Spacer(1, 1.2*cm))
story.append(Paragraph("Based on Gray's Anatomy for Students & THIEME Atlas of Anatomy", cover_date))
story.append(Paragraph("Prepared: June 16, 2026", cover_date))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# TABLE OF CONTENTS (manual)
# ══════════════════════════════════════════════════════════════════════════════
story.append(chapter_header("TABLE OF CONTENTS", C_NAVY))
story.append(Spacer(1, 0.4*cm))

toc_items = [
    ("1", "Pelvis and Pelvic Organs",       "Hip Bone, Pelvic Floor, Urinary System, Reproductive Systems"),
    ("2", "Lower Extremity",                "Osteology, Joints, Muscles, Soft Parts"),
    ("3", "Vertebral Column",               "Osteology, Vertebrae, Discs, Ligaments, Muscles"),
    ("4", "Head and Neck",                  "Skull, Mandible, Facial Muscles, Neck Triangles"),
    ("5", "Neuroanatomy",                   "CNS, Brain Parts, Cranial Nerves, Spinal Cord, PNS"),
]
for num, title, sub in toc_items:
    story.append(Paragraph(f"<b>Chapter {num}: {title}</b>", sec_title))
    story.append(Paragraph(sub, body))
    story.append(hr(C_BLUE, 0.5))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# CHAPTER 1: PELVIS AND PELVIC ORGANS
# ══════════════════════════════════════════════════════════════════════════════
story.append(chapter_header("PELVIS AND PELVIC ORGANS", C_BLUE, "Chapter 1"))
story.append(Spacer(1, 0.3*cm))

# --- 1.1 Hip Bone ---
story.append(Paragraph("1.1  Hip Bone (Os Coxae)", sec_title))
story.append(hr(C_BLUE))
story.append(Paragraph(
    "The hip bone (os coxae) is a large, irregular bone formed by the fusion of three bones: "
    "<b>ilium</b> (superior), <b>ischium</b> (posteroinferior), and <b>pubis</b> (anteroinferior). "
    "They meet at the <b>acetabulum</b> – the cup-shaped socket for the femoral head. "
    "Fusion is complete by puberty (16–18 years).", body))

story.append(info_box("KEY FEATURES OF THE HIP BONE", [
    "Iliac crest: superior border of ilium; extends from ASIS to PSIS",
    "ASIS (Anterior Superior Iliac Spine): attachment of inguinal ligament and sartorius",
    "AIIS (Anterior Inferior Iliac Spine): attachment of rectus femoris",
    "Iliac fossa: concave inner surface of ilium; iliacus muscle origin",
    "Greater sciatic notch: becomes the greater sciatic foramen",
    "Ischial spine: separates greater and lesser sciatic notches",
    "Ischial tuberosity: weight-bearing when seated; hamstring origin",
    "Obturator foramen: largest foramen in body; mostly closed by obturator membrane",
    "Pubic symphysis: fibrocartilaginous secondary cartilaginous joint anteriorly",
    "Acetabulum: formed by ilium (2/5), ischium (2/5), pubis (1/5)",
], C_LBLUE, C_BLUE))
story.append(Spacer(1, 0.3*cm))

for el in img("pelvis_diagram.png", caption_text="Fig 1.1: Hip Bone and Pelvis — Bony Landmarks, Pelvic Inlet/Outlet, Male vs Female Pelvis"):
    story.append(el)
story.append(Spacer(1, 0.3*cm))

# Pelvis table
story.append(Paragraph("Male vs Female Pelvis – Key Differences", sub_title))
story.append(two_col_table(
    ["Feature", "Male Pelvis", "Female Pelvis"],
    [
        ["Shape",           "Heart-shaped inlet",           "Oval/circular inlet"],
        ["Angle of pubic arch", "< 70° (narrow, subpubic angle)", "> 80° (wide, gynecoid)"],
        ["Pelvic inlet",    "Smaller, more oval",           "Larger, wider"],
        ["Acetabula",       "Larger, faces laterally",      "Smaller, faces anterolaterally"],
        ["Sacrum",          "Narrow, long, more curved",    "Wide, short, less curved"],
        ["Ischial spines",  "More prominent",               "Less prominent"],
        ["Obturator foramen","Oval",                        "Triangular"],
        ["Overall",         "Tall, narrow, heavy",          "Shorter, wider, adapted for childbirth"],
    ]
))
story.append(Spacer(1, 0.3*cm))

# --- 1.2 Pelvic Floor ---
story.append(Paragraph("1.2  Pelvic Floor Muscles (Pelvic Diaphragm)", sec_title))
story.append(hr(C_BLUE))
story.append(Paragraph(
    "The pelvic floor is a muscular sheet that closes the inferior pelvic aperture, supports "
    "pelvic viscera, and resists increases in intra-abdominal pressure. It consists of the "
    "<b>levator ani</b> and <b>coccygeus</b> muscles.", body))

story.append(two_col_table(
    ["Muscle", "Origin", "Insertion", "Action", "Nerve Supply"],
    [
        ["Pubococcygeus (part of levator ani)", "Body of pubis", "Anococcygeal ligament, coccyx", "Supports pelvic viscera, constricts vagina/rectum", "Pudendal nerve (S3,S4)"],
        ["Puborectalis (part of levator ani)", "Body of pubis", "Sling behind anorectal junction", "Maintains anorectal angle (continence)", "Nerve to levator ani (S3,S4)"],
        ["Iliococcygeus (part of levator ani)", "Ischial spine, obturator fascia", "Coccyx, anococcygeal ligament", "Supports pelvic floor", "Pudendal nerve (S3,S4)"],
        ["Coccygeus", "Ischial spine", "Sacrum and coccyx", "Supports pelvic floor, flexes coccyx", "Branches of S4, S5"],
    ]
))
story.append(Spacer(1, 0.3*cm))

# --- 1.3 Kidney ---
story.append(Paragraph("1.3  Kidney", sec_title))
story.append(hr(C_BLUE))
story.append(Paragraph(
    "<b>Location:</b> Retroperitoneal, on the posterior abdominal wall, on either side of the vertebral column. "
    "Right kidney: T12–L3 (slightly lower due to liver). Left kidney: T11–L2 (slightly higher). "
    "Each kidney is 11 cm long, 6 cm wide, 3 cm thick, weighing ~150 g.", body))

story.append(info_box("KIDNEY – EXTERNAL FEATURES", [
    "Bean-shaped with medial concavity (hilum) and lateral convexity",
    "Hilum transmits: renal artery, renal vein, ureter, lymphatics, nerve plexus (order front to back: vein, artery, ureter)",
    "Surrounded by: fibrous capsule → perinephric fat → renal fascia (Gerota's) → paranephric fat",
    "Anterior surface: covered by peritoneum (right: liver, duodenum; left: stomach, spleen, pancreas)",
    "Posterior surface: related to diaphragm, psoas major, quadratus lumborum, transversus abdominis",
], C_LTEAL, C_TEAL))

story.append(info_box("KIDNEY – INTERNAL STRUCTURE", [
    "Renal cortex: outer layer, contains glomeruli and proximal/distal tubules; pale appearance",
    "Renal medulla: inner, divided into 8–18 renal pyramids (striated appearance)",
    "Renal columns (of Bertin): cortex projecting between pyramids",
    "Renal papilla: apex of pyramid, projects into minor calyx",
    "Minor calyx → Major calyx (2–3) → Renal pelvis → Ureter",
], C_LTEAL, C_TEAL))
story.append(Spacer(1, 0.2*cm))

for el in img("kidney_textbook.png", caption_text="Fig 1.2: Internal Structure of the Kidney (Gray's Anatomy for Students)"):
    story.append(el)
story.append(Spacer(1, 0.2*cm))
for el in img("kidney_diagram.png", caption_text="Fig 1.3: Kidney – Blood Supply, Nerve Supply, and Structural Features"):
    story.append(el)
story.append(Spacer(1, 0.3*cm))

story.append(info_box("KIDNEY – BLOOD SUPPLY & NERVE SUPPLY", [
    "ARTERY: Renal artery (from aorta at L1) → anterior + posterior divisions → segmental arteries (5) → interlobar → arcuate → interlobular (cortical radiate) arteries",
    "Right renal artery: longer, passes posterior to IVC",
    "Left renal artery: shorter, passes posterior to left renal vein",
    "VEINS: Corresponding veins; left renal vein crosses anterior to aorta, receives left gonadal + left suprarenal veins",
    "LYMPHATICS: Lateral aortic (para-aortic) lymph nodes",
    "NERVE SUPPLY: Renal plexus (T10–L1) via least splanchnic nerve; sympathetic: vasoconstrictor; parasympathetic: minimal",
], C_LPUR, C_PURPLE))
story.append(Spacer(1, 0.3*cm))

# --- 1.4 Ureter ---
story.append(Paragraph("1.4  Ureter", sec_title))
story.append(hr(C_BLUE))
story.append(two_col_table(
    ["Feature", "Details"],
    [
        ["Length", "25 cm (abdominal 12.5 cm + pelvic 12.5 cm)"],
        ["Diameter", "3 mm; 3 sites of narrowing (PUJ, pelvic brim, VUJ)"],
        ["Location", "Retroperitoneal; crosses bifurcation of common iliac artery to enter pelvis"],
        ["Blood Supply", "Multiple sources: renal a., gonadal a., aorta, common/internal iliac a., vesical a."],
        ["Nerve Supply", "T11–L2 (pain refers to groin and genitalia); parasympathetic S2–S4"],
        ["Relations (right)", "Psoas major, IVC, gonadal vessels, right colic vessels"],
        ["Relations (left)", "Psoas major, gonadal vessels, left colic vessels, sigmoid mesentery"],
        ["In female pelvis", "Ureter passes under uterine artery ('water under the bridge') – surgical importance"],
    ]
))
story.append(Spacer(1, 0.3*cm))

# --- 1.5 Urinary Bladder ---
story.append(Paragraph("1.5  Urinary Bladder", sec_title))
story.append(hr(C_BLUE))
story.append(Paragraph(
    "The urinary bladder is a hollow muscular organ that stores urine. When empty, it lies in the "
    "true pelvis; when full, it rises into the abdominal cavity.", body))
story.append(two_col_table(
    ["Feature", "Details"],
    [
        ["Shape (empty)", "Tetrahedral (4 surfaces: superior, 2 inferolateral, posterior/base)"],
        ["Shape (full)", "Ovoid"],
        ["Capacity", "400–600 mL; first urge at ~300 mL"],
        ["Trigone", "Triangular smooth area between 2 ureteric orifices and internal urethral orifice; most fixed part"],
        ["Detrusor muscle", "3 layers of smooth muscle; innermost layer forms internal urethral sphincter"],
        ["Blood supply", "Superior + inferior vesical arteries (internal iliac a.); venous plexus → internal iliac v."],
        ["Nerve supply", "Sympathetic T11–L2 (filling/storage); Parasympathetic S2–S4 (micturition/emptying)"],
        ["Male relations", "Posterior: rectum, seminal vesicles, vas deferens"],
        ["Female relations", "Posterior: uterus and vagina"],
    ]
))
story.append(Spacer(1, 0.3*cm))

# --- 1.6 Urethra ---
story.append(Paragraph("1.6  Urethra", sec_title))
story.append(hr(C_BLUE))
story.append(two_col_table(
    ["Feature", "Male Urethra", "Female Urethra"],
    [
        ["Length", "20 cm", "4 cm"],
        ["Parts", "Preprostatic (0.5 cm), Prostatic (3 cm), Membranous (1.5 cm), Spongy/penile (15 cm)", "Single canal (intramural, pelvic, perineal)"],
        ["Sphincters", "Internal (smooth, involuntary) + External (striated, voluntary)", "Same sphincters; external at perineal membrane"],
        ["Clinical importance", "Stricture common in penile part; catheterization requires 3 curves", "Prone to UTI due to short length; close to vagina"],
        ["Blood supply", "Prostatic/membranous: internal iliac; Spongy: internal pudendal a.", "Internal pudendal + vaginal arteries"],
        ["Nerve supply", "Pudendal nerve (S2–S4)", "Pudendal nerve (S2–S4)"],
    ]
))
story.append(Spacer(1, 0.3*cm))

# --- 1.7 Reproductive Systems ---
story.append(Paragraph("1.7  Male Reproductive System", sec_title))
story.append(hr(C_BLUE))
story.append(two_col_table(
    ["Organ", "Location", "Function", "Blood Supply", "Nerve Supply"],
    [
        ["Testes", "Scrotum (descended from L1 region)", "Spermatogenesis, testosterone production", "Testicular a. (from aorta at L1)", "T10 (pain refers to umbilicus)"],
        ["Epididymis", "Posterior to testis (head, body, tail)", "Sperm maturation and storage", "Testicular a.", "Testicular plexus"],
        ["Vas deferens", "Passes through inguinal canal, pelvic brim", "Transport sperm to ejaculatory duct", "Artery to vas (inferior vesical a.)", "Autonomic"],
        ["Seminal vesicles", "Posterior to bladder", "Secretes fructose-rich seminal fluid", "Inferior vesical a.", "Inferior hypogastric plexus"],
        ["Prostate", "Surrounds urethra below bladder; base to apex", "Secretes PSA, zinc, citrate; contributes to semen", "Inferior vesical + middle rectal a.", "Pelvic plexus (S2–S4)"],
        ["Penis", "External genitalia; root/body/glans", "Urination, copulation", "Internal pudendal a.", "Pudendal nerve (S2–S4)"],
    ]
))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("1.8  Female Reproductive System", sec_title))
story.append(hr(C_BLUE))
story.append(two_col_table(
    ["Organ", "Location/Size", "Function", "Blood Supply", "Nerve Supply"],
    [
        ["Ovaries", "Lateral pelvic wall; 3x1.5x1 cm; post-menopausal atrophied", "Oogenesis, estrogen/progesterone", "Ovarian a. (from aorta L1)", "T10 plexus"],
        ["Uterine tubes", "Between ovary and uterus; 10 cm; parts: infundibulum, ampulla, isthmus, interstitial", "Transport ovum; fertilisation in ampulla", "Ovarian + uterine a.", "T11–L1"],
        ["Uterus", "Between bladder (ant) and rectum (post); 8x5x3 cm; anteflexed + anteverted", "Menstruation, gestation, parturition", "Uterine a. (internal iliac a.)", "Uterovaginal plexus (S2–S4)"],
        ["Vagina", "6–10 cm; posterior fornix deepest", "Birth canal, menstrual outlet, copulation", "Vaginal a. (internal iliac)", "Pudendal nerve (S2–S4)"],
        ["Cervix", "Lower 1/3 of uterus; os opens into vagina", "Mucus plug, dilates in labour", "Uterine a.", "Uterovaginal plexus"],
    ]
))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# CHAPTER 2: LOWER EXTREMITY
# ══════════════════════════════════════════════════════════════════════════════
story.append(chapter_header("LOWER EXTREMITY", C_TEAL, "Chapter 2"))
story.append(Spacer(1, 0.3*cm))

story.append(Paragraph("2.1  Osteology", sec_title))
story.append(hr(C_TEAL))
for el in img("lower_extremity_diagram.png", caption_text="Fig 2.1: Lower Extremity Bones – Femur, Tibia, Fibula, Patella, Tarsals, Metatarsals, Phalanges"):
    story.append(el)
story.append(Spacer(1, 0.2*cm))

story.append(two_col_table(
    ["Bone", "Key Features"],
    [
        ["Femur", "Head (fovea capitis for ligament of head); Neck (angle 126°); Greater + Lesser trochanters; Intertrochanteric line/crest; Linea aspera (shaft); Medial + Lateral condyles; Intercondylar notch; Adductor tubercle"],
        ["Patella", "Sesamoid bone in quadriceps tendon; Base (superior), Apex (inferior); Anterior (non-articular) + Posterior (articular) surfaces"],
        ["Tibia", "Medial + Lateral condyles; Tibial plateau; Tibial tuberosity (patellar ligament attachment); Anterior border (shin); Medial malleolus; Soleal line (posteriorly)"],
        ["Fibula", "Head (proximal); Neck (common peroneal nerve winds here); Shaft; Lateral malleolus; Does NOT bear weight; forms part of ankle mortise"],
        ["Tarsals (7)", "Calcaneus (largest; tuber calcanei; sustentaculum tali), Talus (body, neck, head; no muscle attachments), Navicular, Cuboid, Medial/Intermediate/Lateral Cuneiforms"],
        ["Metatarsals (5)", "Base, shaft, head; 1st is thickest (weight-bearing); 5th has styloid process (peroneus brevis)"],
        ["Phalanges", "Great toe: 2 (proximal, distal); Others: 3 (proximal, middle, distal)"],
    ]
))
story.append(Spacer(1, 0.3*cm))

story.append(Paragraph("2.2  Joints of the Lower Extremity", sec_title))
story.append(hr(C_TEAL))
for el in img("joints_diagram.png", caption_text="Fig 2.2: Hip Joint and Knee Joint – Ligaments, Menisci, Blood and Nerve Supply"):
    story.append(el)
story.append(Spacer(1, 0.2*cm))

story.append(two_col_table(
    ["Joint", "Type", "Ligaments", "Blood Supply", "Nerve Supply", "Movements"],
    [
        ["Hip Joint", "Synovial ball-and-socket", "Iliofemoral (Y-ligament; strongest in body), Pubofemoral, Ischiofemoral, Ligament of head (carries artery to head in children)", "Medial circumflex femoral a. (main), Lateral circumflex femoral a.", "Femoral, obturator, sciatic (L2–S1)", "Flexion, extension, abduction, adduction, medial/lateral rotation, circumduction"],
        ["Knee Joint", "Synovial condylar (hinge + some rotation)", "ACL (prevents forward slide of tibia), PCL (prevents backward slide), MCL, LCL, Patellar ligament, Oblique/arcuate popliteal", "Genicular anastomosis (6 branches around knee)", "Femoral, obturator, sciatic (L3–S1)", "Flexion, extension; medial rotation when flexed (unlocking: popliteus)"],
        ["Ankle Joint (Talocrural)", "Synovial hinge", "Medial (deltoid): 4 parts; Lateral: ATFL, CFL, PTFL", "Malleolar branches of peroneal + anterior/posterior tibial a.", "Superficial + deep peroneal, tibial (L4–S1)", "Dorsiflexion (tibialis anterior), Plantarflexion (gastrocnemius, soleus)"],
        ["Subtalar (Talocalcaneal)", "Synovial plane", "Talocalcaneal interosseous ligament", "Peroneal and tibial a.", "Tibial nerve", "Inversion and eversion"],
        ["Joints of Foot", "Tarsometatarsal, Metatarsophalangeal, Interphalangeal (all synovial)", "Plantar and dorsal ligaments, plantar plate", "Plantar and dorsal arteries", "Medial + Lateral plantar nerves", "Flexion, extension, adduction, abduction"],
    ]
))
story.append(Spacer(1, 0.3*cm))

story.append(Paragraph("2.3  Key Muscles of the Lower Extremity", sec_title))
story.append(hr(C_TEAL))
story.append(two_col_table(
    ["Muscle", "Origin", "Insertion", "Nerve", "Action"],
    [
        ["Gluteus maximus", "Posterior ilium, sacrum, coccyx", "Iliotibial tract, gluteal tuberosity", "Inferior gluteal n. (L5,S1,S2)", "Extension + lateral rotation of hip"],
        ["Gluteus medius", "Outer ilium (between anterior and posterior gluteal lines)", "Greater trochanter (lateral)", "Superior gluteal n. (L4,L5,S1)", "Abduction; anterior fibres medially rotate"],
        ["Gluteus minimus", "Outer ilium (between anterior and inferior gluteal lines)", "Greater trochanter (anterior)", "Superior gluteal n. (L4,L5,S1)", "Abduction; medial rotation"],
        ["Iliopsoas", "Iliac fossa (iliacus) + T12–L5 bodies (psoas)", "Lesser trochanter", "Femoral n. (L1,L2,L3)", "Flexion of hip; psoas laterally flexes spine"],
        ["Quadriceps femoris", "Rectus femoris: AIIS; Vasti: femur shaft", "Tibial tuberosity (via patellar ligament)", "Femoral n. (L2,L3,L4)", "Extension of knee; rectus also flexes hip"],
        ["Hamstrings", "Ischial tuberosity (biceps also from linea aspera)", "Tibia (semimembranosus, semitendinosus), fibular head (biceps)", "Sciatic n. – tibial division (L5,S1,S2)", "Flexion of knee, extension of hip"],
        ["Gastrocnemius", "Medial + lateral femoral condyles", "Calcaneus (via Achilles tendon)", "Tibial nerve (S1,S2)", "Plantarflexion, assists knee flexion"],
        ["Soleus", "Posterior tibia and fibula (soleal line)", "Calcaneus (via Achilles tendon)", "Tibial nerve (S1,S2)", "Plantarflexion (postural muscle)"],
        ["Tibialis anterior", "Lateral tibia, interosseous membrane", "Medial cuneiform + 1st metatarsal base", "Deep peroneal n. (L4,L5)", "Dorsiflexion + inversion"],
        ["Peroneus longus", "Lateral fibula (upper 2/3)", "Medial cuneiform + 1st metatarsal base (plantar)", "Superficial peroneal n. (L5,S1)", "Eversion + plantarflexion; supports arches"],
    ]
))
story.append(Spacer(1, 0.3*cm))

story.append(Paragraph("2.4  Important Soft Part Regions", sec_title))
story.append(hr(C_TEAL))

story.append(info_box("FEMORAL TRIANGLE", [
    "Boundaries: Superior – inguinal ligament; Lateral – sartorius; Medial – adductor longus",
    "Floor: iliopsoas (lateral), pectineus (medial)",
    "Roof: fascia lata + cribriform fascia (over saphenous opening)",
    "Contents (lateral to medial): Femoral Nerve, Femoral Artery, Femoral Vein, Femoral Canal (lymphatics) – mnemonic: NAVL or NAVeL",
    "Femoral canal: contains deep inguinal lymph node (Cloquet's node), fat; site of femoral hernia",
], C_LGOLD, C_GOLD))

story.append(info_box("POPLITEAL FOSSA", [
    "Boundaries: Superolateral – biceps femoris; Superomedial – semitendinosus/semimembranosus; Inferolateral – lateral head of gastrocnemius; Inferomedial – medial head of gastrocnemius; Floor – popliteal surface of femur, knee joint capsule, popliteus",
    "Roof: popliteal fascia + skin",
    "Contents (superficial to deep): tibial nerve, common peroneal nerve, popliteal vein, popliteal artery, popliteal lymph nodes",
    "Popliteal artery is deepest and most difficult to palpate; divides into anterior + posterior tibial arteries at lower border of popliteus",
], C_LRED, C_RED))

story.append(info_box("ADDUCTOR CANAL (Hunter's Canal)", [
    "Location: Middle third of medial thigh; subsartorial canal",
    "Boundaries: Anteromedially – sartorius; Posteriorly – adductor longus and magnus; Laterally – vastus medialis",
    "Contents: Femoral artery, femoral vein (posterior to artery), nerve to vastus medialis, saphenous nerve",
    "Femoral artery exits through adductor hiatus in adductor magnus to become popliteal artery",
], C_LPUR, C_PURPLE))

story.append(info_box("ARCHES OF THE FOOT (Important for exams!)", [
    "Medial longitudinal arch: calcaneus → talus → navicular → cuneiforms → 1st–3rd metatarsals (highest arch; maintained by tibialis posterior, peroneus longus, plantar fascia, plantar calcaneonavicular ligament)",
    "Lateral longitudinal arch: calcaneus → cuboid → 4th–5th metatarsals (lower, less mobile)",
    "Transverse arch: bases of all 5 metatarsals + distal tarsals",
    "Flat foot (pes planus): loss of medial arch; associated with tibialis posterior tendon dysfunction",
    "Pes cavus: exaggerated arch; associated with Charcot-Marie-Tooth disease",
], C_LTEAL, C_TEAL))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# CHAPTER 3: VERTEBRAL COLUMN
# ══════════════════════════════════════════════════════════════════════════════
story.append(chapter_header("VERTEBRAL COLUMN", C_GREEN, "Chapter 3"))
story.append(Spacer(1, 0.3*cm))

story.append(Paragraph("3.1  Overview and Curvatures", sec_title))
story.append(hr(C_GREEN))
for el in img("vertebral_column_diagram.png", caption_text="Fig 3.1: Vertebral Column – Regional Differences, Curvatures, Typical Vertebra, and Intervertebral Disc"):
    story.append(el)
story.append(Spacer(1, 0.2*cm))

story.append(two_col_table(
    ["Region", "Number", "Curvature", "Key Features"],
    [
        ["Cervical",   "7 (C1–C7)",   "Lordosis (secondary)", "Transverse foramina (vertebral artery); bifid spine; C1 = atlas (no body, no spine); C2 = axis (odontoid/dens); C7 = vertebra prominens"],
        ["Thoracic",   "12 (T1–T12)", "Kyphosis (primary)",  "Costal facets (rib articulation); long spinous processes directed inferiorly"],
        ["Lumbar",     "5 (L1–L5)",   "Lordosis (secondary)", "Massive bodies; no transverse foramina or costal facets; horizontal spinous process; L4–L5 most common disc herniation"],
        ["Sacral",     "5 (fused)",   "Kyphosis (primary)",  "Sacral canal, foramina (anterior + posterior); sacral promontory; lateral mass (ala)"],
        ["Coccygeal",  "4 (fused)",   "Continues sacral kyphosis", "Rudimentary; coccyx may fracture from direct trauma"],
    ]
))
story.append(Spacer(1, 0.2*cm))

story.append(info_box("TYPICAL VERTEBRA FEATURES (T3–T9 most typical)", [
    "Body: cylindrical, weight-bearing; connected by IV discs",
    "Pedicles: 2 short bony projections from posterolateral body; form vertebral arch",
    "Laminae: 2 flat plates from pedicles meeting in midline",
    "Spinous process: projects posteriorly from laminae junction; palpable",
    "Transverse processes: 2 lateral projections from pedicle-lamina junction; muscle attachment",
    "Superior + Inferior articular processes: bear articular facets; form zygapophyseal joints",
    "Vertebral foramen: enclosed by body (anteriorly) + arch (posteriorly); forms spinal canal",
    "Intervertebral foramina: formed between adjacent pedicles; transmits spinal nerves and vessels",
], C_LGOLD, C_GOLD))

story.append(Paragraph("3.2  Intervertebral Disc", sec_title))
story.append(hr(C_GREEN))
story.append(two_col_table(
    ["Feature", "Details"],
    [
        ["Structure", "Annulus fibrosus (outer fibrocartilage rings) + Nucleus pulposus (central gelatinous core)"],
        ["Location", "Between all vertebrae C2–S1 except C1/C2; thickest in lumbar region"],
        ["Function", "Shock absorption; allows movement; contributes 25% of spinal column height"],
        ["Blood supply", "Avascular in adults; nutrition via diffusion from adjacent vertebral bodies"],
        ["Nerve supply", "Annulus fibrosus: sinuvertebral nerve (recurrent meningeal branch); nucleus pulposus: no nerve supply"],
        ["Herniation", "Posterolateral herniation most common (nucleus pulposus through weakest part of annulus); L4/L5 most common, then L5/S1; compresses next lower nerve root"],
        ["Clinical: L4/L5 disc", "Compresses L5 root: foot drop, weakness of dorsiflexion, loss of sensation dorsum of foot"],
        ["Clinical: L5/S1 disc", "Compresses S1 root: weakness of plantarflexion, loss of ankle jerk, lateral foot numbness"],
    ]
))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("3.3  Vertebral Ligaments", sec_title))
story.append(hr(C_GREEN))
story.append(two_col_table(
    ["Ligament", "Location", "Function"],
    [
        ["Anterior longitudinal ligament (ALL)", "Anterior surface of vertebral bodies (occiput to sacrum)", "Prevents hyperextension; supports anterior annulus"],
        ["Posterior longitudinal ligament (PLL)", "Posterior surface of vertebral bodies inside canal", "Prevents hyperflexion; supports posterior annulus (weaker laterally – why posterolateral disc herniation occurs)"],
        ["Ligamentum flavum", "Between adjacent laminae; yellow (elastin)", "Resists flexion; maintains lordosis; thickens in degenerative disease causing canal stenosis"],
        ["Interspinous ligaments", "Between adjacent spinous processes", "Limits flexion"],
        ["Supraspinous ligament", "Tips of spinous processes; becomes ligamentum nuchae in neck", "Limits flexion"],
        ["Intertransverse ligaments", "Between transverse processes", "Limits lateral flexion to opposite side"],
    ]
))

story.append(Paragraph("3.4  Muscles of the Vertebral Column", sec_title))
story.append(hr(C_GREEN))
story.append(two_col_table(
    ["Group", "Muscles", "Action", "Nerve Supply"],
    [
        ["Superficial back muscles (extrinsic)", "Trapezius, Latissimus dorsi, Levator scapulae, Rhomboids", "Act on upper limb/scapula", "Spinal accessory (CN XI), thoracodorsal, dorsal scapular nerves"],
        ["Erector spinae (sacrospinalis)", "Iliocostalis (lateral), Longissimus (intermediate), Spinalis (medial)", "Extension and lateral flexion of vertebral column; maintain posture", "Posterior rami of spinal nerves"],
        ["Transversospinal group", "Semispinalis, Multifidus, Rotatores", "Rotation and extension; proprioception", "Posterior rami of spinal nerves"],
        ["Suboccipital muscles", "Rectus capitis posterior major/minor, Obliquus capitis superior/inferior", "Extension and rotation of head at atlanto-occipital joint", "Suboccipital nerve (C1 posterior ramus)"],
    ]
))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# CHAPTER 4: HEAD AND NECK
# ══════════════════════════════════════════════════════════════════════════════
story.append(chapter_header("HEAD AND NECK", C_ORANGE, "Chapter 4"))
story.append(Spacer(1, 0.3*cm))

story.append(Paragraph("4.1  Skull and Mandible (Osteology)", sec_title))
story.append(hr(C_ORANGE))
for el in img("head_neck_diagram.png", caption_text="Fig 4.1: Head and Neck – Skull Bones, Mandible, Facial Muscles, Triangles of the Neck"):
    story.append(el)
story.append(Spacer(1, 0.2*cm))

story.append(two_col_table(
    ["Bone", "Location", "Key Features"],
    [
        ["Frontal", "Anterior cranium, forehead", "Frontal sinus; supraorbital margin; glabella; metopic suture (sometimes persists)"],
        ["Parietal (x2)", "Superior lateral cranium", "Parietal eminence; grooves for middle meningeal vessels; sagittal suture (between them); coronal suture (with frontal)"],
        ["Temporal (x2)", "Lateral skull below parietal", "External acoustic meatus; mastoid process (SCM attachment); styloid process; petrous part (houses inner ear, carotid canal, jugular foramen); zygomatic process"],
        ["Occipital", "Posterior and base of skull", "Foramen magnum (medulla/spinal cord); occipital condyles (atlanto-occipital joint); external occipital protuberance (EOP); lambdoid suture"],
        ["Sphenoid", "Central skull base (butterfly shape)", "Greater + lesser wings; sella turcica (pituitary fossa); optic canal; superior orbital fissure; foramen rotundum (V2); foramen ovale (V3); foramen spinosum (middle meningeal a.)"],
        ["Ethmoid", "Anterior skull base, medial orbit", "Cribriform plate (olfactory nerves CN I); crista galli; perpendicular plate (nasal septum); ethmoid sinuses"],
        ["Nasal (x2)", "Bridge of nose", "Form bridge of nose"],
        ["Zygomatic (x2)", "Cheekbone", "Temporal process (forms zygomatic arch with temporal); orbital floor"],
        ["Lacrimal (x2)", "Medial orbit", "Groove for nasolacrimal duct"],
        ["Vomer", "Posterior inferior nasal septum", "Forms inferior part of bony nasal septum"],
    ]
))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("Mandible", sub_title))
story.append(two_col_table(
    ["Part", "Features"],
    [
        ["Body",         "Horizontal part; mental foramen (mental nerve and vessels exits here; between premolars); symphysis menti anteriorly"],
        ["Ramus (x2)",   "Vertical parts; condylar process (articulates at TMJ); coronoid process (temporalis attachment); mandibular notch between them"],
        ["Angle",        "Junction of body and ramus; masseter attachment; palpable externally"],
        ["Mandibular foramen", "On medial surface of ramus; inferior alveolar nerve enters here; guarded by lingula"],
        ["Nerve supply", "Inferior alveolar nerve (V3); mental nerve exits at mental foramen"],
        ["Blood supply", "Inferior alveolar artery (from maxillary a., branch of ECA)"],
        ["Joints",       "Temporomandibular joint (TMJ): synovial, bicondylar; articular disc divides into upper and lower compartments; mandibular nerve (V3), auriculotemporal nerve"],
    ]
))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("4.2  Muscles of the Face (Facial Expression)", sec_title))
story.append(hr(C_ORANGE))
story.append(two_col_table(
    ["Muscle", "Action", "Nerve Supply"],
    [
        ["Orbicularis oculi", "Closes eye (orbital part: voluntary; palpebral: blinking)", "Facial nerve CN VII (temporal + zygomatic branches)"],
        ["Orbicularis oris", "Closes and purses lips", "Facial nerve (buccal + marginal mandibular branches)"],
        ["Zygomaticus major", "Draws angle of mouth upward and laterally (smiling)", "Facial nerve (zygomatic + buccal branches)"],
        ["Buccinator", "Compresses cheek; keeps food between teeth when chewing", "Facial nerve (buccal branch)"],
        ["Frontalis", "Raises eyebrows, wrinkles forehead", "Facial nerve (temporal branch)"],
        ["Corrugator supercilii", "Draws eyebrows medially (frowning)", "Facial nerve (temporal branch)"],
        ["Nasalis", "Dilates and compresses nares", "Facial nerve (zygomatic + buccal)"],
        ["Platysma", "Depresses mandible, draws angle of mouth down; tenses neck skin", "Facial nerve (cervical branch)"],
        ["Mentalis", "Everts lower lip", "Facial nerve (marginal mandibular)"],
    ]
))
story.append(Paragraph("NOTE: ALL muscles of facial expression are supplied by Facial Nerve (CN VII). Lesion causes Bell's palsy.", key_point))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("Muscles of Mastication", sub_title))
story.append(two_col_table(
    ["Muscle", "Origin", "Insertion", "Action", "Nerve"],
    [
        ["Masseter",          "Zygomatic arch", "Angle + ramus of mandible (lateral)", "Elevation of mandible (jaw closure)", "Mandibular n. V3"],
        ["Temporalis",        "Temporal fossa", "Coronoid process + ramus", "Elevation (anterior fibres); retraction (posterior fibres)", "Deep temporal nn. V3"],
        ["Medial pterygoid",  "Medial surface of lateral pterygoid plate", "Medial surface of ramus + angle", "Elevation; protrusion; contralateral excursion", "Mandibular n. V3"],
        ["Lateral pterygoid", "Greater wing of sphenoid + lateral pterygoid plate", "Condylar neck + articular disc of TMJ", "Protrusion; depression; ipsilateral excursion; opens mouth", "Mandibular n. V3"],
    ]
))
story.append(Paragraph("NOTE: ALL muscles of mastication supplied by Mandibular nerve V3. They are derived from 1st pharyngeal arch.", key_point))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("4.3  Triangles of the Neck", sec_title))
story.append(hr(C_ORANGE))
story.append(info_box("ANTERIOR TRIANGLE (bounded by: midline, SCM, lower border of mandible)", [
    "Submental triangle: below chin; contains submental lymph nodes",
    "Digastric (submandibular) triangle: submandibular gland, hypoglossal nerve (CN XII), facial artery/vein",
    "Carotid triangle: common carotid artery bifurcation (at C4), internal + external carotid arteries, internal jugular vein, vagus nerve (CN X), hypoglossal nerve (CN XII), ansa cervicalis",
    "Muscular triangle: infrahyoid strap muscles, thyroid gland, trachea",
], C_LRED, C_RED))

story.append(info_box("POSTERIOR TRIANGLE (bounded by: SCM, trapezius, middle third of clavicle)", [
    "Occipital triangle: occipital artery, accessory nerve (CN XI) – important as it crosses superficially",
    "Subclavian (supraclavicular) triangle: subclavian artery (3rd part), brachial plexus roots/trunks, subclavian vein",
    "Floor: splenius capitis, levator scapulae, scalene muscles",
    "Accessory nerve (CN XI): crosses posterior triangle superficially just beneath deep fascia – highly vulnerable in surgery!",
], C_LPUR, C_PURPLE))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# CHAPTER 5: NEUROANATOMY
# ══════════════════════════════════════════════════════════════════════════════
story.append(chapter_header("NEUROANATOMY", C_PURPLE, "Chapter 5"))
story.append(Spacer(1, 0.3*cm))

story.append(Paragraph("5.1  Overview of the Central Nervous System (CNS)", sec_title))
story.append(hr(C_PURPLE))
for el in img("brain_diagram.png", caption_text="Fig 5.1: Brain – Forebrain, Midbrain, Hindbrain, Cerebellum, Cranial Nerves, Spinal Cord"):
    story.append(el)
story.append(Spacer(1, 0.2*cm))

story.append(two_col_table(
    ["Division", "Components", "Key Functions"],
    [
        ["Forebrain (Prosencephalon)", "Cerebral hemispheres, Basal ganglia, Thalamus, Hypothalamus, Lateral + 3rd ventricles", "Higher cognitive functions, sensory relay, autonomic control, emotion"],
        ["Midbrain (Mesencephalon)", "Cerebral peduncles, Superior + Inferior colliculi, Substantia nigra, Cerebral aqueduct (of Sylvius)", "Visual + auditory reflexes, motor relay, pupillary reflex"],
        ["Hindbrain (Rhombencephalon)", "Pons, Medulla oblongata, Cerebellum, 4th ventricle", "Autonomic functions, coordination, balance"],
    ]
))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("5.2  Cerebral Hemispheres and Lobes", sec_title))
story.append(hr(C_PURPLE))
story.append(two_col_table(
    ["Lobe", "Location", "Key Functions / Areas"],
    [
        ["Frontal", "Anterior to central sulcus", "Primary motor cortex (precentral gyrus), prefrontal cortex (personality, planning, judgment), Broca's area (speech production, dominant hemisphere, usually left)"],
        ["Parietal", "Between central + lateral sulci", "Primary somatosensory cortex (postcentral gyrus), spatial awareness, Wernicke's area (speech comprehension – posterior temporal/parietal)"],
        ["Temporal", "Below lateral (Sylvian) fissure", "Primary auditory cortex (Heschl's gyri), memory (hippocampus), language comprehension (Wernicke's area), emotion (amygdala)"],
        ["Occipital", "Posterior", "Primary visual cortex (calcarine fissure/area 17), visual processing"],
        ["Insula (Island of Reil)", "Deep to lateral fissure", "Autonomic function, pain, taste, visceral sensation"],
    ]
))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("5.3  Thalamus and Hypothalamus", sec_title))
story.append(hr(C_PURPLE))
story.append(info_box("THALAMUS – The Relay Station", [
    "Paired egg-shaped masses of grey matter flanking the 3rd ventricle",
    "Connected by massa intermedia (interthalamic adhesion)",
    "Function: relay ALL sensory information (except smell) to cerebral cortex",
    "Key nuclei: VPL (body sensory relay), VPM (face sensory relay via trigeminal), LGN (visual), MGN (auditory), Pulvinar (association), VL/VA (motor relay from basal ganglia/cerebellum)",
    "Blood supply: Posterior communicating artery (thalamoperforating), posterior cerebral artery",
], C_LPUR, C_PURPLE))

story.append(info_box("HYPOTHALAMUS – The Master Regulator", [
    "Floor and walls of the 3rd ventricle (below thalamus)",
    "Controls: pituitary gland (releasing/inhibiting hormones), autonomic nervous system",
    "Functions: temperature regulation, hunger/satiety, thirst, circadian rhythms, water balance (ADH via posterior pituitary), sleep-wake cycle, emotional responses",
    "Key nuclei: suprachiasmatic (circadian), supraoptic + paraventricular (ADH, oxytocin), lateral hypothalamus (hunger), ventromedial (satiety), mammillary bodies (memory)",
    "Blood supply: Circle of Willis perforators",
], C_LPUR, C_PURPLE))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("5.4  Cerebellum", sec_title))
story.append(hr(C_PURPLE))
story.append(two_col_table(
    ["Feature", "Details"],
    [
        ["Location", "Posterior cranial fossa; behind pons and medulla; below tentorium cerebelli"],
        ["Parts", "Two hemispheres + vermis (midline); Anterior lobe, Posterior lobe, Flocculonodular lobe"],
        ["Cortex layers", "Molecular layer (outer), Purkinje cell layer (middle), Granular layer (inner)"],
        ["Deep nuclei", "Dentate (largest), Emboliform, Globose, Fastigial (medial)"],
        ["Connections", "3 peduncles: Inferior (with medulla), Middle (with pons – largest), Superior (with midbrain)"],
        ["Function", "Coordination of voluntary movement, balance, muscle tone, motor learning; DOES NOT initiate movement"],
        ["Clinical", "Cerebellar lesions = ipsilateral signs: DANI (Dysdiadochokinesia, Ataxia, Nystagmus, Intention tremor) + dysarthria, hypotonia"],
        ["Blood supply", "PICA (posterior inferior cerebellar a.), AICA, Superior cerebellar artery – branches of basilar/vertebral"],
    ]
))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("5.5  Basal Ganglia", sec_title))
story.append(hr(C_PURPLE))
story.append(info_box("BASAL GANGLIA – Motor Control", [
    "Components: Caudate nucleus + Putamen (= Striatum), Globus pallidus (internus + externus), Substantia nigra (midbrain), Subthalamic nucleus",
    "Caudate + Putamen = Striatum; Putamen + Globus pallidus = Lentiform nucleus",
    "Function: Modulate voluntary movement (especially initiation, scaling); procedural learning; habit formation",
    "Direct pathway (Go): Striatum → GPi/SNr inhibited → Thalamus disinhibited → Cortex activated",
    "Indirect pathway (No-Go): Striatum → GPe → STN → GPi/SNr excited → Thalamus inhibited → Cortex less active",
    "Dopamine (from SNc) facilitates direct and inhibits indirect pathway",
    "Parkinson's disease: loss of dopaminergic neurons in substantia nigra → resting tremor, rigidity, bradykinesia, postural instability",
    "Huntington's disease: degeneration of striatum (caudate first) → chorea, cognitive decline",
], C_LPUR, C_PURPLE))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("5.6  Ventricles and CSF", sec_title))
story.append(hr(C_PURPLE))
story.append(two_col_table(
    ["Ventricle", "Location", "Key Points"],
    [
        ["Lateral ventricles (1st + 2nd)", "Within each cerebral hemisphere; C-shaped", "Anterior (frontal), body (parietal), posterior (occipital), inferior (temporal) horns; connected to 3rd ventricle via interventricular foramina (of Monro)"],
        ["3rd ventricle", "Between thalami; slit-like", "Communicates with lateral ventricles (above) and 4th ventricle via cerebral aqueduct (of Sylvius)"],
        ["4th ventricle", "Between pons/medulla and cerebellum", "Communicates with subarachnoid space via foramina of Luschka (lateral x2) and Magendie (median x1)"],
        ["CSF production", "Choroid plexus (mainly lateral ventricles); 500 mL/day; total ~150 mL circulating", "CSF: clear, colourless; glucose ~2/3 of blood glucose; protein <45 mg/dL"],
        ["CSF absorption", "Arachnoid granulations (villi) into superior sagittal sinus", "Raised ICP if obstructed → hydrocephalus"],
    ]
))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("5.7  Blood Supply to the Brain", sec_title))
story.append(hr(C_PURPLE))
story.append(info_box("CIRCLE OF WILLIS (Circulus Arteriosus)", [
    "Formed by: 2x Internal carotid arteries (enter via carotid canal), 2x Anterior cerebral arteries (ACA), Anterior communicating artery (ACoA), 2x Posterior cerebral arteries (PCA), 2x Posterior communicating arteries (PCoA)",
    "ACA: supplies medial cortex (leg area of motor/sensory cortex)",
    "MCA (Middle cerebral artery): largest branch of ICA; supplies lateral cortex (face, arm, Broca's and Wernicke's areas)",
    "PCA: supplies occipital lobe (visual cortex), thalamus, posterior temporal lobe",
    "ACA + MCA from internal carotid system (anterior circulation)",
    "PCA from basilar artery (vertebral → basilar system = posterior circulation)",
    "Aneurysm at ACoA: most common site; can compress optic chiasm → bitemporal hemianopia",
    "Aneurysm at PCoA: compresses CN III → pupil-involving 3rd nerve palsy",
], C_LRED, C_RED))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("5.8  Cranial Nerves", sec_title))
story.append(hr(C_PURPLE))
story.append(Paragraph("Mnemonic for names: <b>Oh Oh Oh To Touch And Feel Very Good Velvet Ah Heaven</b>", key_point))
story.append(Paragraph("Mnemonic for type (S=Sensory, M=Motor, B=Both): <b>Some Say Marry Money But My Brother Says Big Brains Matter More</b>", key_point))
story.append(two_col_table(
    ["CN", "Name", "Type", "Function", "Exit from Skull"],
    [
        ["I",    "Olfactory",           "Sensory",  "Smell", "Cribriform plate (ethmoid)"],
        ["II",   "Optic",               "Sensory",  "Vision", "Optic canal"],
        ["III",  "Oculomotor",          "Motor",    "Eye movement (SR, IR, MR, IO); levator palpebrae; pupillary constriction (parasympathetic)", "Superior orbital fissure"],
        ["IV",   "Trochlear",           "Motor",    "Superior oblique (intorts + depresses eye)", "Superior orbital fissure"],
        ["V",    "Trigeminal",          "Both",     "V1 (ophthalmic): forehead/cornea sensation; V2 (maxillary): cheek/upper teeth; V3 (mandibular): jaw/lower teeth + muscles of mastication", "V1: SOF; V2: foramen rotundum; V3: foramen ovale"],
        ["VI",   "Abducens",            "Motor",    "Lateral rectus (abducts eye)", "Superior orbital fissure"],
        ["VII",  "Facial",              "Both",     "Facial expression muscles; taste anterior 2/3 tongue (chorda tympani); lacrimation; salivation (submandibular + sublingual glands)", "Stylomastoid foramen"],
        ["VIII", "Vestibulocochlear",   "Sensory",  "Hearing (cochlear) + Balance (vestibular)", "Internal acoustic meatus"],
        ["IX",   "Glossopharyngeal",    "Both",     "Taste + sensation posterior 1/3 tongue; carotid sinus reflex; parotid gland (parasympathetic)", "Jugular foramen"],
        ["X",    "Vagus",               "Both",     "Pharynx/larynx motor; parasympathetic to thorax/abdomen to transverse colon", "Jugular foramen"],
        ["XI",   "Accessory",           "Motor",    "SCM (ipsilateral head turn) + Trapezius (shoulder shrug)", "Jugular foramen"],
        ["XII",  "Hypoglossal",         "Motor",    "All intrinsic + extrinsic tongue muscles (except palatoglossus); tongue deviates to SAME side as lesion", "Hypoglossal canal"],
    ]
))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("5.9  Spinal Cord", sec_title))
story.append(hr(C_PURPLE))
story.append(two_col_table(
    ["Feature", "Details"],
    [
        ["Extent", "Foramen magnum → L1/L2 in adults (L3 in neonates); below this is cauda equina"],
        ["Enlargements", "Cervical (C5–T1): brachial plexus; Lumbar (L1–S2): lumbosacral plexus"],
        ["Conus medullaris", "Tapered end of spinal cord at L1/L2; below is filum terminale"],
        ["Cauda equina", "Bundle of lumbar + sacral nerve roots below conus medullaris; floats in CSF"],
        ["Lumbar puncture", "Done at L3/L4 or L4/L5 (below conus) to avoid cord injury; patient flexed"],
        ["Grey matter", "H-shaped; Anterior horn (motor neurons), Posterior horn (sensory), Lateral horn (sympathetic T1–L2, parasympathetic S2–S4)"],
        ["White matter", "Ascending tracts (sensory): dorsal columns (fine touch/proprioception) and spinothalamic (pain/temp). Descending: corticospinal (motor)"],
        ["Dorsal columns", "Ipsilateral; cross in medulla (gracile + cuneate nuclei); fine touch, vibration, proprioception"],
        ["Spinothalamic tract", "Cross immediately at spinal level (anterior commissure); contralateral; pain + temperature"],
        ["Blood supply", "Anterior spinal artery (1) + posterior spinal arteries (2) from vertebral arteries + radicular arteries"],
    ]
))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("5.10  Spinal Segments and Key Dermatomes/Myotomes", sec_title))
story.append(hr(C_PURPLE))
story.append(two_col_table(
    ["Level", "Key Dermatome / Reflex / Myotome"],
    [
        ["C3,C4,C5",    "Diaphragm (C3,4,5 keeps the diaphragm alive); C4 = shoulder tip; C5 = lateral arm"],
        ["C5,C6",       "Biceps reflex; C5 = deltoid + biceps; C6 = supinator reflex; wrist extension; thumb sensation"],
        ["C7",          "Triceps reflex; wrist flexion; finger extension; middle finger sensation"],
        ["C8,T1",       "Intrinsic hand muscles; ring + little finger"],
        ["T4",          "Nipple level"],
        ["T10",         "Umbilicus; testicular/ovarian pain referred here"],
        ["L1",          "Inguinal ligament area"],
        ["L3,L4",       "Knee jerk (patellar reflex); quadriceps; medial leg sensation"],
        ["L4,L5",       "Foot dorsiflexion; dorsum of foot; L5 = big toe extension (test for L5 nerve root)"],
        ["S1,S2",       "Ankle jerk (Achilles reflex); plantarflexion; lateral foot; posterior leg"],
        ["S2,S3,S4",    "Perineum + bladder/bowel control; S3,4 = penile erection"],
    ]
))
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph("5.11  Peripheral Nervous System (PNS)", sec_title))
story.append(hr(C_PURPLE))
story.append(info_box("PERIPHERAL NERVE STRUCTURE", [
    "Endoneurium: surrounds individual nerve fibres",
    "Perineurium: surrounds a fascicle (bundle of fibres)",
    "Epineurium: surrounds entire nerve",
    "Peripheral nerve injury classification (Seddon): Neuropraxia (conduction block, intact axon) → Axonotmesis (axon disrupted, sheath intact) → Neurotmesis (complete nerve division, worst prognosis)",
    "Peripheral nerve injury classification (Sunderland): Grade 1–5",
    "Wallerian degeneration: distal axon + myelin degenerate after axon cut; macrophages clear debris; Schwann cells form bands of Büngner to guide regeneration",
    "Nerve regeneration: ~1 mm/day or ~25 mm/month",
], C_LGOLD, C_GOLD))

story.append(Spacer(1, 0.2*cm))

# Quick Reference Box
story.append(info_box("QUICK EXAM MEMORY AIDS", [
    "Femoral triangle contents (lateral → medial): N-A-V-E-L (Nerve, Artery, Vein, Empty space, Lymphatics)",
    "Rotator cuff muscles: SITS (Supraspinatus, Infraspinatus, Teres minor, Subscapularis)",
    "Cranial nerves: Oh Oh Oh To Touch And Feel Very Good Velvet Ah Heaven",
    "Carpal bones: Some Lovers Try Positions That They Can't Handle (Scaphoid, Lunate, Triquetrum, Pisiform, Trapezium, Trapezoid, Capitate, Hamate)",
    "Hip dislocation nerve at risk: posterior dislocation → sciatic nerve; anterior → femoral nerve",
    "Common peroneal nerve winds around neck of fibula → foot drop (if injured)",
    "Facial nerve palsy: lower motor neuron (Bell's palsy) → whole ipsilateral face; upper motor neuron → forehead SPARED (bilateral cortical representation)",
    "Knee unlocking: popliteus (lateral rotation of femur on fixed tibia, or medial rotation of tibia on fixed femur)",
    "Disc herniation: L4/L5 → L5 root (foot drop); L5/S1 → S1 root (lost ankle jerk)",
    "Circle of Willis: formed by ICA (x2), ACA (x2), ACoA, PCA (x2), PCoA (x2)",
], colors.HexColor("#fefce8"), C_GOLD))

story.append(PageBreak())

# ── Back cover / References ────────────────────────────────────────────────
story.append(chapter_header("REFERENCES & SOURCES", C_NAVY))
story.append(Spacer(1, 0.4*cm))
refs = [
    "Gray's Anatomy for Students, 4th Edition – Drake, Vogl & Mitchell (Elsevier)",
    "THIEME Atlas of Anatomy: General Anatomy and Musculoskeletal System – Gilroy et al.",
    "Netter's Atlas of Human Anatomy – Frank H. Netter (Elsevier)",
    "Imaging Anatomy: Bones, Joints, Vessels and Nerves Vol. 3 – THIEME",
    "Color Atlas of Human Anatomy (Vols 1–3) – Thieme/Schünke et al.",
    "Last's Anatomy, Regional and Applied – Chummy Sinnatamby",
]
for r in refs:
    story.append(Paragraph(f"\u2022  {r}", bullet))
story.append(Spacer(1, 0.5*cm))
story.append(Paragraph("Good luck on your exam tomorrow! You've got this.", 
    S("Good", fontSize=14, fontName="Helvetica-Bold", textColor=C_TEAL, alignment=TA_CENTER)))

# ── BUILD ────────────────────────────────────────────────────────────────────
doc.build(story, canvasmaker=NumberedCanvas)
print(f"PDF created: {OUTPUT}")