嘿，我看了你这个Shiny应用里的div适配问题，咱们来一步步搞定它～

首先看你代码里的小问题：你虽然给div加了width: 100%;，但外面套的splitLayout默认带了布局限制，导致内容没法真正跟着屏幕走；而且如果没处理好盒模型，内边距这类元素还可能让内容溢出屏幕。

给你两个解决方案，按需选：

方案1：移除不必要的splitLayout（单内容列推荐） #

如果你的splitLayout里只有这一个div，那完全可以去掉它，直接用div承载内容，布局会更灵活：

library(shiny) 

ui <- fluidPage(
  uiOutput("preview")
)

server <- function(input, output, session) {
  
  deployExeList <- function(){
    return(
      shiny::div(
        class = "", 
        style = "width: 100%; padding: 0 15px; box-sizing: border-box;",
        shiny::withMathJax(
          shiny::HTML(
            markdown::markdownToHTML(
              text = "### **aaa/bbbb: ccc000.**\n### In recent years, automatic analyses using novel NLP methods have been used to investigate language abnormalities in schizophrenia. In contrast, only a few studies used automated language analyses in bipolar disorder. To our knowledge, no previous research compared automated language characteristics of first-episode psychosis (FEP) and bipolar disorder (FEBD) using NLP methods",
              fragment.only = TRUE
            )
          )
        )
      )
    )
  }
  
  output$preview <- renderUI({
    deployExeList()
  })
}

shinyApp(ui, server)

这里的关键修改：

• 删掉了splitLayout，避免它带来的多余布局限制
• 给div加了box-sizing: border-box;：这个属性能让div的内边距、边框算在100%宽度里，不会导致内容溢出
• 加了padding: 0 15px;：让内容不要紧贴屏幕边缘，看着更舒服，你可以根据需求调整这个值

方案2：保留splitLayout（多内容列需要时用） #

如果确实需要用splitLayout放多列内容，那给它加上cellWidths = "100%"参数，确保单元格占满父容器：

library(shiny) 

ui <- fluidPage(
  uiOutput("preview")
)

server <- function(input, output, session) {
  
  deployExeList <- function(){
    return(
      splitLayout(
        id=paste0("slexe"),
        cellWidths = "100%", # 让splitLayout单元格占满宽度
        shiny::div(
          class = "", 
          style = "width: 100%; box-sizing: border-box;",
          shiny::withMathJax(
            shiny::HTML(
              markdown::markdownToHTML(
                text = "### **aaa/bbbb: ccc000.**\n### In recent years, automatic analyses using novel NLP methods have been used to investigate language abnormalities in schizophrenia. In contrast, only a few studies used automated language analyses in bipolar disorder. To our knowledge, no previous research compared automated language characteristics of first-episode psychosis (FEP) and bipolar disorder (FEBD) using NLP methods",
                fragment.only = TRUE
              )
            )
          )
        )
      )
    )
  }
  
  output$preview <- renderUI({
    deployExeList()
  })
}

shinyApp(ui, server)

这样修改后，splitLayout的单元格会占满整个屏幕宽度，里面的div也会跟着适配，内容自然就不会溢出了。

总的来说，核心就是让容器宽度设置正确，并用box-sizing处理好盒模型——markdown渲染的内容本身会自动换行，只要容器适配屏幕，内容就会跟着适配啦～

备注：内容来源于stack exchange，提问作者Lev