!DOCTYPE html
html lang=ru
head
    meta charset=UTF-8 
    meta name=viewport content=width=device-width, initial-scale=1 
    titleHellotitle
    style
        body {
            margin 0;
            height 100vh;
            display flex;
            justify-content center;
            align-items center;
            background-color #f0f0f0;
            font-family Arial, sans-serif;
            font-size 48px;
            color #333;
        }
    style
head
body
    hello
body
html