I'm lucky to have learned the web with Angular 2.x

It scopes CSS to components by default, and keeps HTML, CSS and JavaScript seperate.

Vue single-file components (SFC[0]) still works this way.

    <template>
    <!-- Largely just HTML -->
    </template>

    <script setup lang="ts">
    // JS/TS as you would expect
    </script>

    <style scoped>
    /* Component scoped styles here */
    </style>

[0] Vue SFC docs: https://vuejs.org/guide/scaling-up/sfc.html