string siteCollectionUrl = "https://tenantname.sharepoint.com/sites/sitename";
string userName = "username@tenant.onmicrosoft.com";
string password = "yourpassword";

// Namespace: Microsoft.SharePoint.Client
ClientContext ctx = new ClientContext(siteCollectionUrl);

// Namespace: System.Security
SecureString secureString = new SecureString();
password.ToList().ForEach(secureString.AppendChar);

// Namespace: Microsoft.SharePoint.Client
ctx.Credentials = new SharePointOnlineCredentials(userName, secureString);

// Namespace: Microsoft.SharePoint.Client
Site site = ctx.Site;

ctx.Load(site);
ctx.ExecuteQuery();
Web web = ctx.Web;

ctx.Load(web,w => w.ServerRelativeUrl,w => w.Lists);

List list = web.Lists.GetByTitle("List1");

ctx.Load(list);
CamlQuery camlQuery = new CamlQuery();
ListItemCollection itemColl = list.GetItems(camlQuery);

ctx.Load(itemColl);
ctx.ExecuteQuery();
foreach (ListItem item in itemColl)

{
    Console.WriteLine(item["Title"].ToString());
    foreach (var fieldValue in item.FieldValuesAsHtml.FieldValues)
    {
        Console.WriteLine(fieldValue.Key);
        Console.WriteLine(fieldValue.Value);//double quotes are replaced by "
        //eg. Check for "Continue demo.." button. is getting as
        //Check for "Continue demo.." button.
    }
}