[Bug] Only shows value from one theme

[gburning]

Describe the bug
I'm trying to implement the theming feature. Unfortunately, it doesn't seem to work. At least not in the way I would expect.

With the following CSS, only one theme will be listed when hovering --color-foo under p:

body {
    --color-foo: red;
}

.theme-light {
    --color-foo: blue;
}

.theme-dark {
    --color-foo: green;
}

p {
    color: var(--color-foo);
}

I would expect both themes to be included under "Themes" and for "Rendered" to show either only the body definition or all of the possible definitions (depending on theme). Instead it only shows the value for one theme in both cases:

Details (please complete the following information):

• OS: macOS Sequoia 15.6.1
• VSCode version: 1.103.2 (Universal)
• Extension version: 2.6.5