/* Add your css code here */
/*
Variable Definitions:
  --r-bg: Sets the background color.
  --r-tx: Sets the text color.
  --r-h1: Sets the color for h1, h2, and h3 headings.
  --r-lk: Sets the link text color.
  --r-lk-h: Sets the hover color for link text.
  --r-br: Sets the border color.
  --r-bg-fr: Sets the background color for input forms.
  --r-tx-lk: Sets the menu link text color.
  --r-tx-lk-h: Sets the hover color for menu link text.
  --r-bg-lk: Sets the background color for menu links.
  --r-bg-lk-h: Sets the hover background color for menu links.
  --r-tx-bt: Sets the button text color.
  --r-tx-bt-h: Sets the hover color for button text.
  --r-bg-bt: Sets the button background color.
  --r-bg-bt-h: Sets the hover background color for buttons.
*/

/*
Regions Names, each region has an ID and a Class with the same name.
You can use .page-wrapper or #page-wrapper
#page-wrapper {}
#primary-sidebar-menu {}
#fixed-search-block {}
#popup-login-block {}
#header {}
#primary-menu {}
#welcome-text {}

#top-container {}
#top-box-first {}
#top-box-second {}
#top-box-third {}

#system-messages {}
#breadcrumb {}
#page-title {}

#main-container {}
#sidebar-box-first {}
#sidebar-box-main {}
#sidebar-box-second {}

#bottom-container {}
#bottom-box-first {}
#bottom-box-second {}
#bottom-box-third {}
#bottom-box-fourth {}

#footer-container {}
#footer-box-first {}
#footer-box-second {}
#footer-box-third {}

#footer-menu {}
#copyright {}

Examples:

#page-wrapper {
  background-color: var(--r-bg);
  color: var(--r-tx);
  border-color: var(--r-br);
}

h1, h2, h3 {
  color: var(--r-h1);
}

a:not(li.nav__menu-item a) {
  color: var(--r-lk);
  color: var(--r-lk-h);
}

input:not(.button) {
  background-color: var(--r-bg-fr);
}

li.nav__menu-item a {
  color: var(--r-tx-lk);
  background-color: var(--r-bg-lk);
}

li.nav__menu-item a:hover {
  color: var(--r-tx-lk-h);
  background-color: var(--r-bg-lk-h);
}

button:not(li.nav__menu-item button) {
  color: var(--r-tx-bt);
  background-color: var(--r-bg-bt);
}

button:not(li.nav__menu-item button):hover {
  color: var(--r-tx-bt-h);
  background-color: var(--r-bg-bt-h);
}
https://www.drupal.org/docs/extending-drupal/themes/contributed-themes/solo/instructions-for-developers-on-using-colors-in-solo-theme
*/