My theme for https://obsidian.md/

obsidian.css

.theme-dark {
  --text-accent: hsla(250, 54%, 65%, 1);
  --text-accent-hover: hsla(248, 71%, 72%, 1);
}

body {
  --font-monospace: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace, Courier;
}

.markdown-preview-view code {
  padding: 3px 6px;
  font-size: 0.9em;
  tab-size: 2;
}

p {
  padding: 3px 0;
}

ul, ol {
  padding-left: calc(1.5em + 4px);
  margin-block-start: 0px;
  margin-block-end: 0px;
}

li {
  margin: 2px 0;
  padding-top: 3px;
  padding-bottom: 3px;
}

li > p {
  padding: 3px 2px;
  margin: 2px 0;
}

li > p:first-child {
  padding-top: 0;
  margin-top: 0;
}

li > p:last-child {
  padding-bottom: 0;
  margin-bottom: 0;
}

.markdown-preview-view blockquote {
  margin: 1rem 0;
  border-left: 5px solid var(--background-modifier-border);
  border-radius: 5px;
  padding: 0.5em 0.9em;
  font-size: 1.1rem;
  line-height: 1.5;
}

.tag {
  background-color: hsla(0, 0%, 22%, 1);
  border-radius: 5px;
  padding: 2px 6px;
  margin-left: 3px;
  text-decoration: none;
}

.markdown-preview-view h1, .markdown-preview-view h2, .markdown-preview-view h3, .markdown-preview-view h4, .markdown-preview-view h5, .markdown-preview-view h6 {
  font-weight: 600;
}

.markdown-preview-view h1 {
  font-size: 2.0625rem;
  line-height: 1.636;
}

.markdown-preview-view h2 {
  margin-block-start: 1rem;
  margin-block-end: 0;
  font-size: 1.625rem;
  line-height: 1.654;
}

.markdown-preview-view h3 {
  margin-block-start: 0.5rem;
  margin-block-end: 0;
  font-size: 1.25rem;
  line-height: 1.75;
}

.markdown-preview-view h4 {
  font-size: 1rem;
  line-height: 1.8125;
}

.markdown-preview-view h5 {
  font-size: 0.8125rem;
  line-height: 1.846;
  color: #888;
}

.markdown-preview-view h6 {
  font-size: 0.8125rem;
  line-height: 1.846;
  color: #888;
}