Not able to add Lighting design to button - Visualforce

Question

I am trying to create a form using VF but I am getting old style button so I have tried styleClass attribute but it is not working

Visualforce Code:

<apex:page standardController="Contact" >
    <apex:form > 
        <apex:pageBlock title="Edit Contact">
            <apex:pageBlockSection columns="1">
                <apex:inputField value="{!Contact.FirstName}"/>
                <apex:inputField value="{!Contact.LastName}"/>
                <apex:inputField value="{!Contact.Email}"/>
                <apex:inputField value="{!Contact.Birthdate}"/>
            </apex:pageBlockSection>
            <apex:pageBlockButtons >
                <apex:commandButton styleClass="slds-button" action="{!save}" value="Save"/>
            </apex:pageBlockButtons>
        </apex:pageBlock>
    </apex:form>

So can some one help to add new style to button and if possible then any reference link.

Thanks

Answer 1

For this use case Salesforce made available the Lightning Experience Stylesheets. If you change the <apex:page> tag to:

<apex:page standardController="Contact" lightningStylesheets="true">

it should work.

https://developer.salesforce.com/docs/atlas.en-us.pages.meta/pages/vf_dev_best_practices_slds_lightningstylesheets.htm