Jeykll file to import not found or unreadable: base

Ok, so, I somehow managed to break my jekyll website and I don’t understand why. When I try to serve the site with jekyll I am prompted the following error:

/usr/lib/ruby/gems/2.7.0/gems/jekyll-sass-converter-2.1.0/lib/jekyll/converters/scss.rb:190:in `rescue in convert': Error: File to import not found or unreadable: base. (Jekyll::Converters::Scss::SyntaxError)
        on line 24:1 of main.scss
>> @import

   ^

My directory structure looks like so:

.
├── README.md
├── _site
│   ├── README.md
│   └── src
│       ├── assets
│       │   ├── posts
│       │   │   └── 202-07-23-about
│       │   │       └── avatar.png
│       │   └── screenshot.png
│       ├── general
│       │   └── 2020
│       │       └── 07
│       │           └── 23
│       │               └── about.html
│       └── index.html
└── src
    ├── assets
    │   ├── images
    │   ├── posts
    │   │   └── 202-07-23-about
    │   │       └── avatar.png
    │   └── screenshot.png
    ├── _config.yml
    ├── css
    │   └── main.scss
    ├── _includes
    │   ├── footer.html
    │   └── head.html
    ├── index.html
    ├── _layouts
    │   ├── default.html
    │   ├── page.html
    │   └── post.html
    ├── _posts
    │   └── 2020-07-23-about.md
    ├── _sass
    │   ├── _base.scss
    │   └── _syntax-highlighting.scss
    └── _templates
        ├── draft
        ├── page
        └── post

I assume it has trouble finding the _base.scss file? How can I tell it where it needs to look? It is pointing out the error is in line 24, but that doesn’t really makes much sense. My main.scss looks like so:

---
# Only the main Sass file needs front matter (the dashes are enough)
---
@charset "utf-8";

// Our variables
$base-font-family: 'PT Serif', Georgia, Times, 'Times New Roman', serif;
$base-font-size:   12pt;
$small-font-size:  $base-font-size * 0.875;
$base-line-height: 1.5;

$mono-font-family: 'Source Code Pro', Menlo, Monaco, Inconsolata;

$text-color:       hsl(0, 0%, 25%);

$alt-color:        hsl(0, 70%, 46%);
$alt-color-darker: darken($alt-color, 6%);

$article-bg-color: hsl(35, 36%, 95%);
$background-color: darken($article-bg-color, 6%);
$bg-color-darker:  darken($article-bg-color, 15%);
$alt-text-color:   darken($article-bg-color, 60%);

$subdued-border:   rgba($bg-color-darker, 0.5);

// Import partials from `sass_dir` (defaults to `_sass`)
@import
  "base",
  "syntax-highlighting"
;

Can someone point out how I can fix this problem?