The text inside a quoteblock is not readable when using the light mode of the seriph theme.

[Bktero]

Describe the bug

The text inside a quoteblock is not readable when using the light mode of the seriph theme. Indeed, the text is white and the background is almost white.

To Reproduce

1. Use this slides.md:

---
theme: seriph
---
# First Page

> This is a quoted text.

---

# Second Page

> Another text in a quote block.

2. Start the presentation with npm run dev.

3. Web brower opens, slide 1 is displayed, dark mode is used by default. Quoteblock has dark background and light text. The text can be read perfectly:

4. Use the tool bar to switch to light mode. The presentation refreshes, colors change.

5. Now, quoteblock has light background and light text. The text cannot be read:

Notes:

• Quoteblock on the second slide is OK in both dark and light modes.
• Bug cannot be reproduced with default theme.

Desktop (please complete the following information):

• OS: Windows 10
• NodeJS: 14.17.0
• Browser: Chrome 90.0.4430.212

Here is package.json:

{
  "private": true,
  "scripts": {
    "dev": "slidev --open",
    "build": "slidev build",
    "export": "slidev export"
  },
  "dependencies": {
    "@slidev/cli": "^0.16.0",
    "@slidev/theme-default": "*",
    "@slidev/theme-seriph": "*"
  },
  "name": "slidev"
}