theme1.css

:root {
    /* Theme 1 */
    --theme-background: hsl(222, 26%, 31%);
    --theme-toggle-key-background: hsl(223, 31%, 20%);
    --theme-screen-background: hsl(224, 36%, 15%);
    --theme-del-reset-key: hsl(225, 21%, 49%);
    --theme-del-reset-key-shadow: hsl(224, 28%, 35%);
    --theme-equal-key-toggle: hsl(6, 63%, 50%);
    --theme-equal-key-shadow: hsl(6, 70%, 34%);
    --theme-num-op-keys: hsl(30, 25%, 89%);
    --theme-num-op-keys-shadow: hsl(28, 16%, 65%);
    --theme-num-op-text: hsl(0, 0%, 0%);
    --theme-del-reset-text: hsl(0, 0%, 100%);
    --theme-equal-text: var(--theme-del-reset-text);
    --theme-screen-titlebar-text: var(--theme-del-reset-text);
}