Store package style sheets in the styles/ directory instead of stylesheets/ in the oceanic-theme package

ThemePackage.getStylesheetsPath (/Applications/Atom.app/Contents/Resources/app.asar/src/package.js:458:9)
ThemePackage.getStylesheetPaths (/Applications/Atom.app/Contents/Resources/app.asar/src/package.js:469:32)
ThemePackage.loadStylesheets (/Applications/Atom.app/Contents/Resources/app.asar/src/package.js:451:38)
<unknown> (/Applications/Atom.app/Contents/Resources/app.asar/src/theme-package.js:47:19)
ThemePackage.measure (/Applications/Atom.app/Contents/Resources/app.asar/src/package.js:163:15)
ThemePackage.activate (/Applications/Atom.app/Contents/Resources/app.asar/src/theme-package.js:43:12)

In index.less: Target the selector :host, atom-text-editor instead of .editor for shadow DOM support.

In oceanic-theme/index.less:

Starting from Atom v1.13.0, the contents of atom-text-editor elements are no longer encapsulated within a shadow DOM boundary. This means you should stop using :host and ::shadow pseudo-selectors, and prepend all your syntax selectors with syntax--. To prevent breakage with existing style sheets, Atom will automatically upgrade the following selectors:

• .editor .search-results .marker .region => .editor .search-results .syntax--marker .region

• .editor .search-results .marker.current-result .region => .editor .search-results .syntax--marker.current-result .region

• .comment => .syntax--comment

• .string => .syntax--string

• .constant.numeric => .syntax--constant.syntax--numeric

• .constant.language => .syntax--constant.syntax--language

• .constant.character, .constant.other => .syntax--constant.syntax--character, .syntax--constant.syntax--other

• .variable => .syntax--variable

• .keyword => .syntax--keyword

• .storage => .syntax--storage

• .storage.type => .syntax--storage.syntax--type

• .entity.name.class => .syntax--entity.syntax--name.syntax--class

• .entity.other.inherited-class => .syntax--entity.syntax--other.syntax--inherited-class

• .entity.name.function => .syntax--entity.syntax--name.syntax--function

• .variable.parameter => .syntax--variable.syntax--parameter

• .entity.name.tag => .syntax--entity.syntax--name.syntax--tag

• .entity.other.attribute-name => .syntax--entity.syntax--other.syntax--attribute-name

• .punctuation.section.embedded.begin.asp, .punctuation.section.embedded.end.asp => .syntax--punctuation.syntax--section.syntax--embedded.syntax--begin.syntax--asp, .syntax--punctuation.syntax--section.syntax--embedded.syntax--end.syntax--asp

• .support.function => .syntax--support.syntax--function

• .support.constant => .syntax--support.syntax--constant

• .support.type, .support.class => .syntax--support.syntax--type, .syntax--support.syntax--class

• .punctuation.definition.tag.html, .punctuation.definition.tag.begin.html, .punctuation.definition.tag.end.html => .syntax--punctuation.syntax--definition.syntax--tag.syntax--html, .syntax--punctuation.syntax--definition.syntax--tag.syntax--begin.syntax--html, .syntax--punctuation.syntax--definition.syntax--tag.syntax--end.syntax--html

• .support.other.namespace, .entity.name.type.namespace => .syntax--support.syntax--other.syntax--namespace, .syntax--entity.syntax--name.syntax--type.syntax--namespace

• .support.other.namespace.use-as.php => .syntax--support.syntax--other.syntax--namespace.syntax--use-as.syntax--php

• .variable.language.namespace.php => .syntax--variable.syntax--language.syntax--namespace.syntax--php

• .punctuation.separator.inheritance.php => .syntax--punctuation.syntax--separator.syntax--inheritance.syntax--php

• .entity.other.attribute-name.id.css, .entity.other.attribute-name.class.css => .syntax--entity.syntax--other.syntax--attribute-name.syntax--id.syntax--css, .syntax--entity.syntax--other.syntax--attribute-name.syntax--class.syntax--css

• .entity.other.attribute-name.pseudo-class.css => .syntax--entity.syntax--other.syntax--attribute-name.syntax--pseudo-class.syntax--css

• .support.function.misc.css, .support.constant.property-value.css, .support.constant.font-name.css => .syntax--support.syntax--function.syntax--misc.syntax--css, .syntax--support.syntax--constant.syntax--property-value.syntax--css, .syntax--support.syntax--constant.syntax--font-name.syntax--css

• .support.type.proerty => .syntax--support.syntax--type.proerty

• .constant.numeric.css => .syntax--constant.syntax--numeric.syntax--css

• .variable.parameter.misc.css => .syntax--variable.syntax--parameter.syntax--misc.syntax--css

• .entity.other.tagbraces.twig => .syntax--entity.syntax--other.syntax--tagbraces.syntax--twig

• .keyword.control.twig => .syntax--keyword.syntax--control.syntax--twig

• .variable.other.twig => .syntax--variable.syntax--other.syntax--twig

• .support.function.filter.twig => .syntax--support.syntax--function.syntax--filter.syntax--twig

• .support.function.filter.variable.twig => .syntax--support.syntax--function.syntax--filter.syntax--variable.syntax--twig

• .entity.name.function.twig => .syntax--entity.syntax--name.syntax--function.syntax--twig

• .entity.other.argument.twig => .syntax--entity.syntax--other.syntax--argument.syntax--twig

• .invalid => .syntax--invalid

• .invalid.deprecated => .syntax--invalid.syntax--deprecated

Automatic translation of selectors will be removed in a few release cycles to minimize startup time. Please, make sure to upgrade the above selectors as soon as possible.

In index.less: Use the atom-text-editor tag instead of the editor class.