/* reading mode */
.markdown-preview-view p {
text-align: justify;
text-justify: inter-word;
}
/* source view and live preview */
.markdown-source-view.mod-cm6 .cm-line {
text-align: justify;
text-justify: inter-word;
}
Add to Snippet folder in Dot Obsidian folder. Be sure to activate snippet in Obsidian settings. Hope it works for you.