Once we have a complete working application, it is time for some styling with CSS. In the following example, just some fonts are changed. It is always good, when possible, to control the styles with CSS. There are some widgets, such as plot outputs that are not so easy to handle as the tags assignment is restricted.

In the following CSS, saved as style.css, some of the texts are styled as follows:

.title {
  font-size: 18px;
  font-weight: bold;
}
h1 {
  font-style: italic;
  font-family: impact;
}

As it was explained in Chapter 8, Shiny and HTML/JavaScript, CSS stylesheets can be included with an includeCSS() statement inside UI.R:

# Starting line
shinyUI(fluidPage(
 
 #CSS styling
 includeCSS("PATH_to_CSS_file/style.css"),
 # Application title
 titlePanel("Adult Dataset"),