List page doesn't render theme properly

I encountered a weird issue when trying to display subsection titles on a list page. Compared to single pages in this theme (which is hugo-coder), the text on the list page and its subpages (as shown in the picture below) is too small and too much to the left. Another issue is that content in /content/projects/_index.md didn’t render at all.

enter image description here

The only thing I did was to add a list.html file in /layouts/projects. Why would this happen and how can I render the theme properly on a list page? Thanks!! (GitHub)

{{ define "title" }}
  {{ .Title }} · {{ .Site.Title }}
{{ end }}

{{ define "content" }}

  {{ if (eq $.Parent.Title "Projects") }}
    <ul class="no-bullet">
      {{ range .Paginator.Pages }}
      {{ .Render "li" }}
      {{ end }}
    </ul>
    {{ partial "pagination.html" . }}

  {{ else }}
    {{ range (where .Site.Pages "Section" "projects") }}
      <ul class="no-bullet">
        {{ range .Sections }}
        <li>
            <span class="date">{{ .Date.Format (.Site.Params.dateFormat | default "January 2, 2006" ) }}</span>
            <a class="title" href="{{ .Params.ExternalLink | default .RelPermalink }}">{{ .Title }}</a>
        </li>
        {{ end }}
      </ul>
     {{ end }}
   {{ end }}

{{ end }}

Original post:
Under /content/projects, I have two separate categories, cs and ds. I wish to create a list page that displays the names of these two categories along with the URL to both. I know people asked similar questions before. However, none of the solutions I tried worked for me.

Below are my folder structure (relevant folders only) and the original code in /layouts/_default/list.html and /layout/partial/list.html. Which files should I modify and how in order to display subsections correctly? Thank you so much!!

In /layouts/_default:

{{ define "title" }} {{- if eq .Kind "taxonomy" -}}
  {{- i18n .Data.Singular | title -}}
    {{- print ": " -}}
  {{- end -}}

  {{- .Title }} · {{ .Site.Title -}}
{{ end }}
{{ define "content" }}
   {{ partial "list.html" . }}
{{ end }}

In /layouts/partial:

<section class="container list">
  <h1 class="title">
    {{- if eq .Kind "taxonomy" -}}
      {{- i18n .Data.Singular | title -}}
      {{- print ": " -}}
    {{- end -}}

    {{- .Title -}}
  </h1>
  {{ .Content }}
  <ul>
    {{ range .Paginator.Pages }}
    <li>
      <span class="date">{{ .Date.Format (.Site.Params.dateFormat | default "January 2, 2006" ) }}</span>
      <a class="title" href="{{ .Params.ExternalLink | default .RelPermalink }}">{{ .Title }}</a>
    </li>
    {{ end }}
  </ul>
  {{ partial "pagination.html" . }}
</section>

Folder structure of content and layout:

├── content
│   ├── about.md
│   ├── posts
│   │   └── amazon.md
│   └── projects
│       ├── _index.md
│       ├── cs
│       │   ├── _index.md
│       │   └── covid19.md
│       └── ds
│           ├── _index.md
│           └── covid19.md
├── layouts
│   ├── 404.html
│   ├── _default
│   │   ├── baseof.html
│   │   ├── list.html
│   │   └── single.html
│   ├── index.html
│   ├── partials
│   │   ├── 404.html
│   │   ├── analytics
│   │   │   └── fathom.html
│   │   ├── footer.html
│   │   ├── header.html
│   │   ├── home.html
│   │   ├── list.html
│   │   ├── page.html
│   │   ├── pagination.html
│   │   ├── posts
│   │   │   ├── commento.html
│   │   │   ├── disqus.html
│   │   │   ├── math.html
│   │   │   ├── series.html
│   │   │   └── utteranc.html
│   │   └── taxonomy
│   │       ├── categories.html
│   │       └── tags.html
│   ├── posts
│   │   ├── li.html
│   │   ├── list.html
│   │   └── single.html
│   └── projects
│       └── list.html
...

Please share your project, per the advice at Requesting Help.

Ah sorry, just updated my question with my GitHub repo (also here)!