Vaadin can't find my themes
<p>I've got below error:</p>

<blockquote>
  <p>INFO: Requested resource [/VAADIN/themes/mytheme/styles.css] not found
  from filesystem or through class loader. Add widgetset and/or theme
  JAR to your classpath or add files to WebContent/VAADIN folder.</p>
</blockquote>

<p>I'm using intellij.
Here is my folder structure:</p>

<p><a href="https://i.stack.imgur.com/y68K2.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/y68K2.png" alt="enter image description here"></a></p>

<p>My mytheme.scss:</p>

<pre><code>@import "../valo/valo.scss";
@mixin mytheme {
    @include valo;
    .v-button {
        color: blue;
        background: yellow;
    }
}
</code></pre>

<p>My styles.scss:</p>

<pre><code>@import "mytheme.scss";
@import "addons.scss";
.mytheme {
    @include mytheme;
    @include addons;
}
</code></pre>

<p>My web.xml:
<a href="http://wklej.org/id/2144139/" rel="nofollow noreferrer">http://wklej.org/id/2144139/</a></p>

<p>My pom.xml:
<a href="http://wklej.org/id/2144140/" rel="nofollow noreferrer">http://wklej.org/id/2144140/</a></p>

<p>I have compiled scss like in docs <a href="https://vaadin.com/docs/-/part/framework/themes/themes-compiling.html#themes.compiling.maven" rel="nofollow noreferrer">https://vaadin.com/docs/-/part/framework/themes/themes-compiling.html#themes.compiling.maven</a> and I'm not in production mode.</p>

<p>I don't know what I'm doing wrong. </p>