Remove bold in a shiny sidebar in R - r

Question

I'm new to Shiny and can't figure out how to "unbold" labels (feed rate and operation in the screenshot attached). Here's my code for the UI part:
ui <- fluidPage(titlePanel(""),
sidebarLayout(
sidebarPanel(
# adding the new div tag to the sidebar
tags$div(class="header", checked=NA,
tags$h4(strong("Duty"))),
selectInput('id1', 'Feed rate (m^3/h)', c("All", main$metric[1:3])),
selectInput('id2', 'Operation', c("All", main$metric[4:5])),
mainPanel(DT::dataTableOutput("table"))
))
And here's the screenshot:

Answer 1

You can do this by adding your own style sheet to your Shiny app. First we give the sidebar panel a class sidebar so we can refer to it. Then we can add the following to a file www/style.css:
.sidebar label {
font-weight: 400;
}
Finally we set the theme parameter of your fluidPage to "style.css".
ui <- fluidPage(theme="style.css", titlePanel(""),
# content here
))
The result should look like this:

Answer 2

This is another option (you don't have to create a file)
library(shiny)
remove_bold <-"
#expr-container label {
font-weight: 400;
}
"
ui <- fluidPage(
titlePanel("My app"),
sidebarLayout(
sidebarPanel(
tags$style(remove_bold), ####### NEW CODE
tags$div(id = "expr-container", ####### NEW CODE
textInput(inputId = "data2", "Data1", value = "data"))
),
mainPanel(
)
)
)
server <- function(input, output) {
}
shinyApp(ui = ui, server = server)
Inspired in this post: How to change the pickerinput label to fine instead of bold