bottom align a button in R shiny

Question

I cannot figure out a way to bottom align downloadButton with a selectizeInput, i.e.,

library(shiny)

runApp(list(
  ui = shinyUI(fluidPage(
    fluidRow(align="bottom",
      column(12, align="bottom",
             h4("Download Options:"),
             fluidRow(align="bottom", 
                      column(6, selectizeInput("plot_dl", "File Type", width="100%",  
                                               choices = list("PDF"="pdf","PNG"="png"))),
                      column(3, downloadButton('plot1_dl', 'Left Plot')),
                      column(3, downloadButton('plot2_dl', 'Right Plot'))
             )
      )
    ),
    tags$style(type='text/css', "#plot1_dl { width:100%; vertical-align:bottom}"),
    tags$style(type='text/css', "#plot2_dl { width:100%;}")
  )),
  server = function(input, output) {
  }
))

Placing align="bottom" anywhere and everywhere does not throw an error message, but does not have the desired effect either. Tried playing around with the style tags of the buttons, but well out my depth.

Answer 1

Found an ad-hoc fix with margin-top: 25px in the style tag...

library(shiny)

runApp(list(
  ui = shinyUI(fluidPage(
     h4("Download Options:"),
     fluidRow(
       column(6, selectizeInput("plot_dl", "File Type", width="100%",
                                choices = list("PDF"="pdf","PNG"="png"))),
       column(3, downloadButton('plot1_dl', 'Left Plot')),
       column(3, downloadButton('plot2_dl', 'Right Plot'))
     ),
     tags$style(type='text/css', "#plot1_dl { width:100%; margin-top: 25px;}"),
     tags$style(type='text/css', "#plot2_dl { width:100%; margin-top: 25px;}")
  )),
  server = function(input, output) {
  }
))

Answer 2

Other way to do it is to pass style argument in the column function.

runApp(list(
        ui = shinyUI(fluidPage(
                h4("Download Options:"),
                fluidRow(
                        column(6, selectizeInput("plot_dl", "File Type", width="100%",
                                                 choices = list("PDF"="pdf","PNG"="png"))),
                        column(3, style = "margin-top: 25px;", downloadButton('plot1_dl', 'Left Plot')),
                        column(3, style = "margin-top: 25px;", downloadButton('plot2_dl', 'Right Plot'))
                )
        )),
        server = function(input, output) {
        }
))