change site-title color

Hello,
please how to change site title font and color, such as, i’m using Twenty Twenty-One and i tried to make that by adding .site-title {
color: #A27CEF;
font-family: “Rochester”, Sans-serif;
text-decoration: underline;
font-size: 42px;
font-style: bold;
letter-spacing: normal;

line-height: var(–global–line-height-heading);
margin-bottom: calc(var(–global–spacing-vertical) / 6);
}
on the theme editor all went good but when i create a new page, the site title on this page wont change the font it just change the color.

please i need some help i’m a beginner, i hope i don’t maked a mistakes in to my style sheet, thank you in advance.