index.css

@import './list-widget.css';
@import './boards-config-dialog.css';
@import './main.css';
@import './monitor.css';
@import './arduino-select.css';
@import './status-bar.css';
@import './terminal.css';
@import './editor.css';
@import './settings-dialog.css';
@import './debug.css';

.theia-input.warning:focus {
    outline-width: 1px;
    outline-style: solid;
    outline-offset: -1px;
    opacity: 1 !important;
    color: var(--theia-warningForeground);
    background-color: var(--theia-warningBackground);
}

.theia-input.warning {
    background-color: var(--theia-warningBackground);
}

.theia-input.warning::placeholder { /* Chrome, Firefox, Opera, Safari 10.1+ */
    color: var(--theia-warningForeground);
    background-color: var(--theia-warningBackground);
    opacity: 1; /* Firefox */
}

.theia-input.warning:-ms-input-placeholder { /* Internet Explorer 10-11 */
    color: var(--theia-warningForeground);
    background-color: var(--theia-warningBackground);
}

.theia-input.warning::-ms-input-placeholder { /* Microsoft Edge */
    color: var(--theia-warningForeground);
    background-color: var(--theia-warningBackground);
}

/* Makes the sidepanel a bit wider when opening the widget */ 
.p-DockPanel-widget {
    min-width: 200px;
    min-height: 200px;
}

/* Overrule the default Theia CSS button styles. */
button.theia-button,
.theia-button {
    border: 1px solid var(--theia-dropdown-border);
}

button.theia-button:hover,
.theia-button:hover {
    border: 1px solid var(--theia-focusBorder);
}

button.theia-button {
    height: 31px;
}

button.theia-button.secondary {
    background-color: var(--theia-secondaryButton-background);
    color: var(--theia-foreground);
}

button.theia-button.main {
    color: var(--theia-button-foreground);
}