diff --git a/main.pdf b/main.pdf
index d77e9d1..a5a968b 100644
Binary files a/main.pdf and b/main.pdf differ
diff --git a/main.tex b/main.tex
index 0f2535b..7ffc858 100644
--- a/main.tex
+++ b/main.tex
@@ -7,13 +7,20 @@
 \begin{titlepage}
 \pagecolor{ink}\color{paper}
 \begin{tikzpicture}[remember picture,overlay]
-  % the proof pyramid the book climbs — drawn in solid mixed colors, never
-  % transparency: low-opacity fills on a dark ground render as smudge and
-  % vary by viewer. Crisp thin outlines make it read as intentional.
-  \foreach \i/\w in {0/5.4, 1/4.2, 2/3.0, 3/1.8}{
-    \draw[paper!30!ink, line width=0.5pt, fill=paper!8!ink]
+  % The proof pyramid the book climbs. Cover-design law, learned twice:
+  % an unlabeled near-invisible shape on a dark ground reads as a printing
+  % artifact, not a motif. So the pyramid declares itself — visible fills,
+  % named floors, a caption. Solid mixed colors only (transparency on dark
+  % renders as smudge and varies by viewer).
+  \foreach \i/\w/\layer in {0/5.4/Field, 1/4.2/Group law, 2/3.0/Scalars, 3/1.8/Signature}{
+    \draw[paper!45!ink, line width=0.6pt, fill=paper!12!ink]
       ($(current page.center)+(-\w/2,{-3.0+\i*0.95})$) rectangle ++(\w,0.8);
+    \node[paper!80!ink, font=\footnotesize\scshape]
+      at ($(current page.center)+(0,{-2.6+\i*0.95})$) {\layer};
   }
+  \node[paper!55!ink, font=\small\itshape, anchor=north]
+    at ($(current page.center)+(0,-3.35)$)
+    {the proof pyramid this book climbs};
 \end{tikzpicture}
 \vspace*{3.2cm}
 {\fontsize{15}{18}\selectfont\scshape\color{accent} a hands-on course in\par}