R Shiny Image without padding/ stretched across page using css

Question

I'm building a shiny dashboard and I want an image to stretch across the top of the dashboard body with no padding. I'm new to customizing apps and CSS, and I'd prefer to keep my css inline if possible.

This is what I have right now:

I'd like to extend the image as indicated by blue arrows/ red outline below.

Here's code for what I have so far:

library('shiny')
library('shinyjs')
library('shinydashboard')

##########
header<-dashboardHeader(titleWidth = 325)
header$children[[2]]$children <-  
#tags$a(tags$img(src='image.PNG',height='45',width='184'))

######
body<-dashboardBody(  tags$style(".content {background-color: black;}"),
                  useShinyjs(),
                  tags$style(type='text/css', ".skin-blue .main-header .logo {background-color: #000000}" ),
                  tags$style(type='text/css', ".skin-blue .main-header .logo:hover {background-color: #000000}"),
                  tags$style(type='text/css', ".skin-blue .main-header .navbar {background-color: #000000}"),
                  tags$style(type="text/css",".shiny-output-error { visibility: hidden; }",".shiny-output-error:before { visibility: hidden; }"),

                  fluidPage(
                    img(src="img2.PNG",height="100%", width="100%"),
                    tabBox("Menu Surf Database", width = 12,
                           tabPanel("Menu Surf Database", 
                                    tabsetPanel(
                                      tabPanel("LTO Survey results",
                                               h2(strong(textOutput("t"))),
                                               h4(textOutput("Description")),
                                               h2(strong("LTO Results"),align='center'),
                                               h4(strong(textOutput("Price"))),
                                               br(),
                                               plotOutput("Q4plot",height = 200),
                                               br(),br(),
                                               plotOutput("seasonPlot",height=200),
                                               br(),br(),
                                               plotOutput("Q1plot"),
                                               br(),br()),

                                      tabPanel("Demographics",
                                               h2(strong(textOutput("t2"))),
                                               h4(textOutput("Description2")),
                                               h2(strong("Demographics of Top Two Box:"),align='center'),
                                               h3(strong("By Purchase Intent"),align= "center"),
                                               br(),
                                               plotOutput("demoPlot1"),
                                               plotOutput("demoPlot2")
                                      ))),
                           tabPanel("Exploratory Comparison",
                                    tabsetPanel(
                                      tabPanel("Visuals",
                                               h2(strong("Proprietary Menu Surf Results:")),
                                               selectInput("index",label = "Index by:",choices = c("Meal Part","Day Part"),selected = "Meal Part",multiple = FALSE),
                                               checkboxInput("addItem", label="Include sidebar item for comparision?", value = FALSE, width = NULL),
                                               h4(strong("Purchase Intent Indices:")),
                                               plotOutput("prop1"),
                                               h4(strong("Uniqueness Indices:")),
                                               plotOutput("prop2"),
                                               h4(strong("Draw Indices:")),
                                               plotOutput("prop3"),
                                               h4(strong("Cravebility Indices:")),
                                               plotOutput("prop4"),
                                               h4(strong("Brand Fit Indices")),
                                               plotOutput("prop5")        
                                      ),
                                      tabPanel("Tables",
                                               h2(strong("Menu Surf Results, tables:")),
                                               h3("Purchase Intent"),
                                               br(),
                                               dataTableOutput("propTable1")
                                      )))
                    )))


sidebar<-dashboardSidebar(width = 325,
                      conditionalPanel(
                        condition = "$('li.active a').first().html()==='Menu Surf Database'",
                        h4("Filters:"),
                        br(),
                        selectInput('month',label='Month:',choices= month.name,multiple = TRUE,selected = "March"),
                        selectInput("year",label= "Year:",choices= c("2017"),multiple = FALSE,selected = "2017"),
                        selectInput("daypart",label = "Day Part:",choices=c("Breakfast","Lunch/Dinner"),selected = c("Breakfast","Lunch/Dinner"),multiple = TRUE),
                        selectInput("mealpart",label="Meal Part:",choices =c("Adult Beverage","App/Starter","Dessert","Ent/Main Dish","Non-Alcohol Beverage","Side/Extra","Snack"),selected = c("Adult Beverage","App/Starter","Dessert","Ent/Main Dish","Non-Alcohol Beverage","Side/Extra","Snack"),multiple = TRUE),
                        selectInput("courseCategory",label = "Course Category:",choices = c('All','Asian Bowl','Baked Goods','Beef Dish','Beverage','Breaded Other',
                                                                                            'Breaded Protein','Breaded Vegetables','Breads','Breakfast Starch',
                                                                                            'Burgers','Chicken Dish','Combo Plates','Egg Dish','Fish Dish','Fried Dessert',
                                                                                            'Fries','Frozen Beverage','Ice Cream','Mexican','Mixed Grill','Nachos','Pasta/Noodles',
                                                                                            'Pizza','Pork Dish','Salad Main Dish','Sandwich','Shellfish Dish','Soup','Specialty Drinks'
                        ),selected= 'All',multiple = FALSE),
                        #textOutput('test'),
                        uiOutput('restChoices'),
                        uiOutput('itemChoices'),
                        br(),
                        h5("Edit data by demographic features below:"),
                        selectInput('gender',label = "Gender:",choices = c("Female","Male"),multiple = TRUE,selected = c("Female","Male")),
                        selectInput('generation',label = "Generation:",choices = c("Generation Z","Millennials","Generation X","Baby Boomers","Matures"),selected = c("Generation Z","Millennials","Generation X","Baby Boomers","Matures"),multiple = TRUE),
                        selectInput('ethnicity',label ='Ethnicity:',choices = c("Asian","Black/African American (non-Hispanic)","Caucasian (non-Hispanic)","Hispanic","Mixed ethnic background","Other"),selected = c("Asian","Black/African American (non-Hispanic)","Caucasian (non-Hispanic)","Hispanic","Mixed ethnic background","Other"),multiple = TRUE),
                        selectInput('ea',label = 'Eater Archetype:', choices = c("Affluent Socializers","Bargain Hunters","Busy Balancers","FS Hobbyist","FS Hobbyists","Functional Eater","Functional Eaters","Habitual Matures","Health Enthusiast","Health Enthusiasts"),selected = c("Affluent Socializers","Bargain Hunters","Busy Balancers","FS Hobbyist","FS Hobbyists","Functional Eater","Functional Eaters","Habitual Matures","Health Enthusiast","Health Enthusiasts"),multiple = TRUE)
                      ),
                      conditionalPanel(
                        condition = "$('li.active a').first().html()==='Exploratory Comparison'",
                        #h5("The Exploratory Comparison tab allows you to view results for many items. Please filter for your results below."),
                        h4("Filters:"),
                        br(),
                        selectInput('month2',label='Month:',choices= month.name,multiple = TRUE,selected = "March"),
                        selectInput("year2",label= "Year:",choices= c("2017"),multiple = FALSE,selected = "2017"),
                        selectInput("daypart2",label = "Day Part:",choices=c("Breakfast","Lunch/Dinner"),selected = c("Breakfast","Lunch/Dinner"),multiple = TRUE),
                        selectInput("mealpart2",label="Meal Part:",choices =c("Adult Beverage","App/Starter","Dessert","Ent/Main Dish","Non-Alcohol Beverage","Side/Extra","Snack"),selected = c("Adult Beverage","App/Starter","Dessert","Ent/Main Dish","Non-Alcohol Beverage","Side/Extra","Snack"),multiple = TRUE),
                        selectInput("courseCategory2",label = "Course Category:",choices = c('All','Asian Bowl','Baked Goods','Beef Dish','Beverage','Breaded Other',
                                                                                             'Breaded Protein','Breaded Vegetables','Breads','Breakfast Starch',
                                                                                             'Burgers','Chicken Dish','Combo Plates','Egg Dish','Fish Dish','Fried Dessert',
                                                                                             'Fries','Frozen Beverage','Ice Cream','Mexican','Mixed Grill','Nachos','Pasta/Noodles',
                                                                                             'Pizza','Pork Dish','Salad Main Dish','Sandwich','Shellfish Dish','Soup','Specialty Drinks'
                        ),selected= 'All',multiple = FALSE),
                        uiOutput('restChoices2'),
                        br(),
                        h5("Edit data by demographic features below:"),
                        selectInput('gender2',label = "Gender:",choices = c("Female","Male"),multiple = TRUE,selected = c("Female","Male")),
                        selectInput('generation2',label = "Generation:",choices = c("Generation Z","Millennials","Generation X","Baby Boomers","Matures"),selected = c("Generation Z","Millennials","Generation X","Baby Boomers","Matures"),multiple = TRUE),
                        selectInput('ethnicity2',label ='Ethnicity:',choices = c("Asian","Black/African American (non-Hispanic)","Caucasian (non-Hispanic)","Hispanic","Mixed ethnic background","Other"),selected = c("Asian","Black/African American (non-Hispanic)","Caucasian (non-Hispanic)","Hispanic","Mixed ethnic background","Other"),multiple = TRUE),
                        selectInput('ea2',label = 'Eater Archetype:', choices = c("Affluent Socializers","Bargain Hunters","Busy Balancers","FS Hobbyist","FS Hobbyists","Functional Eater","Functional Eaters","Habitual Matures","Health Enthusiast","Health Enthusiasts"),selected = c("Affluent Socializers","Bargain Hunters","Busy Balancers","FS Hobbyist","FS Hobbyists","Functional Eater","Functional Eaters","Habitual Matures","Health Enthusiast","Health Enthusiasts"),multiple = TRUE)

                      ))

########
ui <- 
dashboardPage(
header,
sidebar,
body
 )



 ###########

server<-function(input, output, session){
}

#####

shinyApp(ui = ui, server = server)

Thanks in advance ! :)

Answer 1

I am by no means a CSS expert, but this is how I was able to achieve what you are looking for:

                tags$style(".topimg {
                            margin-left:-30px;
                            margin-right:-30px;
                            margin-top:-15px;
                          }"),
                div(class="topimg",img(src="https://dotunroy.files.wordpress.com/2015/05/happy-people.jpg",height="100%", width="100%")),

I had to choose another image, because I did not have the image you used. But luckily I found some volunteers. Look at all those happy people!