R Shiny custom.css style of Shiny Dashboard. Code inspired by user aagarw30 repo

shiny-vision-custom.css

/* header title font */
.main-header .logo {
  font-family: "helvetica",  serif, Times, "Times New Roman";
  font-weight: bold;
  font-size: 24px;
}

/* background color of header (logo part) */
.skin-blue .main-header .logo {
          background-color: #252525;
}
        
/* logo when hovered */
.skin-blue .main-header .logo:hover {
          background-color: gray;
}
                              
/* background color for remaining part of the header */
.skin-blue .main-header .navbar {
          background-color: #999999;
} 
                              
/* toggle button when hovered  */                    
.skin-blue .main-header .navbar .sidebar-toggle:hover{
         background-color: gray;
}
                              
/* main sidebar */
.skin-blue .main-sidebar {
         background-color: #999999;
} 
                      
/* active sidebar menu item */
.skin-blue .main-sidebar .sidebar .sidebar-menu .active a{
        background-color: white;
        color:black;
}
                          
/* sidebar menuitems when mouse hover */
.skin-blue .main-sidebar .sidebar .sidebar-menu a:hover{
        background-color: gray;
        color:white;
}
                              
/* body */
.content-wrapper, .right-side {
   background-color: #252525;
}

.box.box-solid.box-primary>.box-header {
  background:#999999
}

.box.box-solid.box-primary{
  border-bottom-color:#999999;
  border-left-color:#999999;
  border-right-color:#999999;
  border-top-color:#999999;
}