권장 사항: bootstrap4에서 일반적으로 사용되는 스타일 소개

<link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/4.0.0-beta/css/bootstrap.min.css">
<script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.min.js"></script>
<script src="https://cdn.bootcss.com/popper.js/1.12.5/umd/popper.min.js"></script>
<script src="https://cdn.bootcss.com/bootstrap/4.0.0-beta/js/bootstrap.min.js"></script>

display //标题类 1-4
small //小文本
<abbr> //文本底部下面一条虚线边框

text-muted  柔和
text-primary 重要
text-success 成功
text-info 提示
text-warning 警告
text-danger 危险
text-secondary 副标题
text-dark 深灰色文字
text-light 浅灰色
text-white 白色

table  //默认样式
table-striped //条纹表格
table-bordered //边框表格
table-hover //鼠标悬停
table-dark //黑色背景表格
table-responsive //响应式表格

rounded  //圆角效果
rounded-circle //椭圆效果
img-thumbnail //图片缩略图效果
img-fluid //图片响应式效果
超大屏幕
jumbotron // 屏幕
jumbotron-fluid //没有圆角的全屏幕

alert-success //成功提示信息
alert-dismissable class="close" data-dismiss="alert" //关闭提示框

btn-primary //主要按钮
btn-secondary //次要按钮
btn-success //成功按钮
btn-info //信息按钮
btn-danger //危险
btn-outline-primary //按钮边框
btn-sm btn-lg //小大号按钮
btn-block //块级按钮
active //可用
disabled //禁用

btn-group //按钮组
btn-group-lg|sm|xs 控制按钮组大小
btn-group-vertical 垂直按钮组

progress  //添加一个p
progress-bar //在上面的p中添加一个progress-bar的p

pagination //ul元素上添加
page-item //在li元素上添加page-item

list-group //列表组
list-group-item //列表li
list-group-item-action

card、card-header、card-body、card-footer
card-img-top //图片
card-body、card-title、card-text //图片卡片
card-img-overlay//设置图片为背景

dropdown //下拉菜单默认
button设置dropdown-toggle   data-toggle=“dropdown” //下拉button
dropdown-menu //下拉菜单
a设置样式dropdown-item

navbar、navbar-expand-sm、bg-light
ul：navbar-nav li：nav-item

form-group
label for email
input class form-control

button设置 data-toggle="modal" data-target="#myModal"
<div class="modal fade" id="myModal"></div>
<div class="modal-dialog"></div>
<div class="modal-content"></div>
 <div class="modal-header">
        <h4 class="modal-title">模态框头部</h4>
        <button type="button" class="close" data-dismiss="modal">&times;</button>
      </div>
<div class="modal-body">模态框内容..</div>
<div class="modal-footer"><button type="button" class="btn btn-secondary" data-dismiss="modal">关闭</button></div>