design-themes/theme_treehouse/views/snippets/s_features.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>

<template id="s_features" inherit_id="website.s_features">
    <!-- Section -->
    <xpath expr="//section" position="attributes">
        <attribute name="class" add="pt48 pb48" remove="pt64 pb64" separator=" "/>
    </xpath>
    <!-- Icons -->
    <xpath expr="(//i)[1]" position="attributes">
        <attribute name="class" add="fa-leaf mb-4 rounded-circle" remove="fa-paper-plane-o mb-3 rounded" separator=" "/>
    </xpath>
    <xpath expr="(//i)[2]" position="attributes">
        <attribute name="class" add="fa-flash mb-4 rounded-circle" remove="fa-credit-card mb-3 rounded" separator=" "/>
    </xpath>
    <xpath expr="(//i)[3]" position="attributes">
        <attribute name="class" add="fa-tint mb-4 rounded-circle" remove="fa-flag-o mb-3 rounded" separator=" "/>
    </xpath>
</template>

</odoo>