如何在shiny中设置大小和特定布局

library(shiny)

ui <- fluidPage(
  fluidRow(
    column(width = 6,
           tags$div(style = "width: 300px; height: 200px; background-color: red;"),
           tags$div(style = "width: 300px; height: 200px; background-color: blue;")
    ),
    column(width = 6,
           tags$div(style = "width: 400px; height: 300px; background-color: green;")
    )
  ),
  sidebarLayout(
    sidebarPanel(
      tags$div(style = "width: 200px; height: 400px; background-color: yellow;")
    ),
    mainPanel(
      tags$div(style = "width: 600px; height: 400px; background-color: orange;")
    )
  ),
  splitLayout(
    cellWidths = c("50%", "50%"),
    tags$div(style = "width: 300px; height: 200px; background-color: purple;"),
    tags$div(style = "width: 300px; height: 200px; background-color: pink;")
  )
)

server <- function(input, output) {
  # 服务器逻辑代码
}

shinyApp(ui, server)