Pdf rendering don't render linear gradient but png export works

[yodatak]

Describe the bug
When i export my pdf i don't have the same ouput as the web output, gradient are broken

To Reproduce

1.Create a new slide with

---
# try also 'default' to start simple
theme: academic
# random image from a curated Unsplash collection by Anthony
# like them? see https://unsplash.com/collections/94734566/slidev
background: https://cover.sli.dev
# some information about your slides, markdown enabled
title: Linux
info: |
  ## XXXXX

# author field for exported PDF
author: XXXXXXX

# https://sli.dev/custom/highlighters.html
highlighter: shiki

monaco: true
# Where to load monaco types from, can be 'cdn', 'local' or 'none'
monacoTypesSource: local

# https://sli.dev/guide/drawing
drawings:
  persist: false
# slide transition: https://sli.dev/guide/animations#slide-transitions
transition: slide-left
# enable MDC Syntax: https://sli.dev/guide/syntax#mdc-syntax
mdc: true

fonts:
  sans: Roboto
  serif: Roboto Slab
  mono: Fira Code

addons:
  - slidev-addon-asciinema
  - prettier-plugin-slidev
---

# XXXXX

---
transition: fade-out
---

# Prérequis

- XXXXXXXXXXX [TXX](XXXXXXXXXXX)
- X `XXX`
- XXX ! 🎉

---
layout: image-left
image: ./homepage-overview-diagram-new.svg
backgroundSize: contain
---

# Openstack

XXX **XXXXX** sXXXX

XXX **XXX** <ic-baseline-wind-power /> XXXXXXXXXXXXXXXT <mdi-counter />


---

<style>
 h1 {
  background-color: #2B90B6;
  background-image: linear-gradient(45deg, #4EC5D4 10%, #146b8c 20%);
  background-size: 100%;
  -webkit-background-clip: text;
  -moz-background-clip: text;
  -webkit-text-fill-color: transparent;
  -moz-text-fill-color: transparent;
}

</style>

# My title

XXXX

<http://XXX/>

<twemoji-warning /> XXX :/

- XX: `XX`

- XXX

2. pnpm run export --dark

Desktop (please complete the following information):

• OS: Fedora 40
• Browser: Firefox
• Slidev version:
  my package.json

{
  "name": "linux",
  "type": "module",
  "private": true,
  "scripts": {
    "build": "npx slidev build",
    "dev": "npx slidev --open",
    "export": "npx slidev export slides*.md"
  },
  "dependencies": {
    "@iconify-json/carbon": "^1.1.33",
    "@iconify-json/devicon-plain": "^1.1.40",
    "@iconify-json/fa": "^1.1.8",
    "@iconify-json/heroicons": "^1.1.21",
    "@iconify-json/ic": "^1.1.17",
    "@iconify-json/logos": "^1.1.42",
    "@iconify-json/mdi": "^1.1.66",
    "@iconify-json/noto": "latest",
    "@iconify-json/simple-icons": "1.1.101",
    "@iconify-json/twemoji": "^1.1.15",
    "@iconify-json/uim": "^1.1.9",
    "@iconify-json/vscode-icons": "1.1.33",
    "@slidev/cli": "^0.49.3",
    "@slidev/theme-default": "^0.25.0",
    "slidev-theme-academic": "^1.3.0",
    "vue": "^3.4.27"
  },
  "devDependencies": {
    "playwright-chromium": "^1.44.0",
    "prettier": "3.2.5",
    "prettier-plugin-slidev": "^1.0.5"

  },
  "packageManager": "pnpm@8.15.5"
}

The bad pdf rendering here
slides_copy-export.pdf

The good web rendering

The png export is good

[KermanX]

Noticed this. I think the reason may be the PDF viewer doesn't support background-clip.