bulma (base): loading screen: when the `loading_screen` variable is set before extending `base/base.html`, a loading modal is shown (and must be removed via JavaScript). This avoids the user to try to use an interface which is not reactive or working normally because JS is not fully loaded yet.

#loading_screen {
    /* Loading screen doesn't make sense without JS, and must never be displayed */
    display: none;
}

/**********
 * Panels *
 **********/

/* drawer needs to be opened to have the content visible */
.panel-drawer {
    max-height: none;
    opacity: 1;
}