css put button in corner code example

Example 1: button edges rounded css

button {
  border-radius: 25px;
}

Example 2: how to make a rounded button

<Style TargetType="Button" x:Key="RoundButton">
    <Style.Resources>
        <Style TargetType="Border">
            <Setter Property="CornerRadius" Value="5" />
        </Style>
    </Style.Resources>
</Style>