Uppercase slogan

Hi, Why is the first letter of my slogan (under the site title, upper left corner) first words letter is necessary in capital ? The first letter of each word is displayed as uppercase letter, which is not the case on the text I have typed in the customise panel. I want my slogan to respect what I have typed in text, without uppercase when there is not. Let me know what I need to do (CSS or so) to disable this format issue. My custom slogan text : Directeur de la Photographie What is displayed : Directeur De La Photographie https://bastienchilloux.com