title: Alignment of control widgets on fluidPage in shiny R
body: <p>I am working on a shiny app, but ran into a problem with the placement of widgets depending on the size of the browser window. I am using nested column and fluidRow to place my widgets (see code below). I want the left side of widgets B and D aligned, and the right side of B and E (see Fig 1), but when I increase the size of the window, at some point the alignment of the right side doesn't hold anymore (Fig 2).  </p>
  
  <p>Fig 1: correct layout
  <img src="https://i.stack.imgur.com/3yNDi.png" alt="correct layout">  </p>
  
  <p>Fig 2: incorrect layout
  <img src="https://i.stack.imgur.com/6QuSm.png" alt="incorrect layout"></p>
  
  <p>Here is a reproducible example:<br>
  ui.R:  </p>
  
  <pre><code>library(shiny)
  
  shinyUI(fluidPage(column(
  6,fluidRow(column(6, numericInput("a", label = "A", 0)),
             column(6, numericInput("b", label = "B", 0))),
  fluidRow(
      column(6, numericInput("c", label = "C", 0)),
      column(3, numericInput("d", label = "D", 0)),
      column(3, numericInput("e", label = "E", 0))
  )
   ),
   column(5, offset=1,h1("other stuff"))
  ))
  </code></pre>
  
  <p>server.R:  </p>
  
  <pre><code>library(shiny)
  
  shinyServer(function(input, output) {})
  </code></pre>