verTabs.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>CSS Vertical Tabs</title>
    <style>
        *{
            font-family: sans-serif;
            box-sizing: border-box;
        }
        .tab{
            float: left;
            border: 1px solid  #ccc;
            background-color: #f1f1f1;
            width: 30%;
            height: 300px;
        }
        .tab button{
            display: block;
            background-color: inherit;
            color: black;
            padding: 22px 16px;
            width: 100%;
            border: none;
            outline: none;
            text-align: left;
            cursor: pointer;
            transition: 0.3s;
        }
        .tab button:hover{
            background-color: #ddd;
        }
        .tab button.active{
            background-color: #ccc;
        }
        .tabcontent{
            float: left;
            padding: 0px 12px;
            border: 1px solid #ccc;
            width: 70%;
            border-left: none;
            height: 300px;
            display: none;
        }
    </style>
</head>
<body>
    <!-- Tab-links  -->
    <div class="tab">
        <button class="tablinks" onclick="openCity(event,'London')">London</button>
        <button class="tablinks" onclick="openCity(event,'Paris')">Paris</button>
        <button class="tablinks" onclick="openCity(event,'Tokyo')">Tokyo</button>
    </div>
    <!-- Tabcontent  -->
    <div id="London" class="tabcontent">
        <h3>London</h3>
        <p>London is the capital of England</p>
    </div>
    <div id="Paris" class="tabcontent">
        <h3>Paris</h3>
        <p>Paris is the capital of France</p>
    </div>
    <div id="Tokyo" class="tabcontent">
        <h3>Tokyo</h3>
        <p>Tokyo is the capital of Japan</p>
    </div>

    <script>
        function openCity(evt,cityName){
            //Declare all variables
            var i,tablinks,tabcontent;

            //Get all elements with class="tabcontent" and hide them
            tabcontent= document.getElementsByClassName("tabcontent");
            for(i=0;i<tabcontent.length;i++){
                tabcontent[i].style.display= "none";
            }

            //Get all elements with class="tablinks" and remove the class="active"
            tablinks= document.getElementsByClassName("tablinks");
            for(i=0;i<tablinks.length;i++){
                tablinks[i].className= tablinks[i].className.replace(" active","");
            }

            // Show the current tab, and add the "active" class to the link that opened the tab 
            document.getElementById(cityName).style.display= "block";
            evt.currentTarget.className+= " active";

        }
    </script>
</body>
</html>