@yandex/ui/Button/_theme/Button_theme_normal@desktop.css

Yandex UI components

/**
 * 1. border-width нужен для меняющейся толщины обводки при фокусе.
 */
.Button2_theme_normal::before {
    transition: .1s ease-out;
    transition-property: border-color, border-width, background-color;
}

.Button2_theme_normal:not([aria-disabled='true']):hover::before {
    border-color: rgba(0, 0, 0, .3);
}

.Button2_theme_normal.Button2_checked:not([aria-disabled='true']):hover::before {
    border-color: rgba(129, 103, 0, .6);
}

.utilityfocus.utilityfocus .Button2.Button2_theme_normal:focus::before {
    border-width: 2px; /* 1 */
    border-color: #ffdb4d;
}