fix(theme): correct emphasis opacity in default dark theme

[douira]

Matched the opacity of the emphasis CSS variables to conform to the values stated in the documentation.

If this change is not wanted, the documentation should instead be updated to explain that there is no difference in opacity between the light and dark theme.

Description

The documentation states different opacity values for high, medium and disabled opacity text between light and dark mode. However, the theme only uses the values of the light theme. I've set the correct values as stated in the documentation for the dark theme (and the corresponding snapshot test).

The PR that added these variables: https://github.com/vuetifyjs/vuetify/pull/13674/files#diff-53b5523de35fefbb957b3194ca376f52e49b1562b8715abbeec14437966fb0c6

Markup:

<template>
  <v-app>
    <v-container>
      <v-card theme="light">
        <v-card-text>
          light theme default (high emphasis)
          <div class="text-high-emphasis">high emphasis</div>
          <div class="text-medium-emphasis">medium emphasis</div>
          <div class="text-disabled">disabled emphasis</div>
        </v-card-text>
      </v-card>
      <v-card theme="dark">
        <v-card-text>
          dark theme default (high emphasis)
          <div class="text-high-emphasis">high emphasis</div>
          <div class="text-medium-emphasis">medium emphasis</div>
          <div class="text-disabled">disabled emphasis</div>
        </v-card-text>
        <v-card-text class="old-emphasis">
          dark theme before this PR (emphasis like in light theme)
          <div class="text-high-emphasis">high emphasis</div>
          <div class="text-medium-emphasis">medium emphasis</div>
          <div class="text-disabled">disabled emphasis</div>
        </v-card-text>
      </v-card>
    </v-container>
  </v-app>
</template>

<script>
  export default {
    name: 'Playground',
    setup () {
      return {
        //
      }
    },
  }
</script>

<style>
.old-emphasis {
  --v-high-emphasis-opacity: 0.87;
  --v-medium-emphasis-opacity: 0.6;
  --v-disabled-opacity: 0.38;
}
</style>

[douira]

How do I get cypress to update the snapshot data? I can’t find any documentation on how contributors should use the testing infrastructure.

[KaelWD]

That specific failure is just a cypress bug, you can ignore it: cypress-io/cypress#25913