I am currently writing a book in french which is made of three parts (with \part{}). Using the fancyhdr package, I would like to have the tile of my book on the even pages and the name of the part (and not that of the sections inside it) on the odd pages. How can I achieve that, especially since the book's title ("Éléments de Géométrie") contains accents which are not rendered well by fancyhdr.
Here is a picture of these two problems, the title is not rendered properly (left) and that I would like to print only the name of the part and not that of the section (right).
\usepackage{fancyhdr}
\pagestyle{fancy}
\fancyhf{}
\fancyhead[ER]{\nouppercase\leftmark{Éléments de Géométrie}}
\fancyhead[OL]{\nouppercase\rightmark}
\fancyhead[EL,OR]{\thepage}
For character encoding I use
\usepackage[francais]{babel}
\usepackage[T1]{fontenc}
\usepackage{textcomp}
\usepackage[utf8]{inputenc}
It is important to note that sections name which include accents works fine, for example :



input encoding. Which one do you use? – Bernard Oct 29 '19 at 13:40french, and it's recommended that it be declared via \documentclass, so as to make sure that all language-dependent packages be informed. – Bernard Oct 29 '19 at 14:07