With the command Horizontal line, you can insert a horizontal line into the text – for example, if a separator line is required. Of course, such lines are not limited to HTML documents; they can also be used in normal documents.
Note: This command is not on the ribbon by default. However, you can choose it directly via the hamburger menu 
(on the left in the Quick access toolbar) as in the classic menu interface with the menu command Objects > New horizontal line.
To insert such a line, place the text cursor on the desired line and choose the menu command Object > New horizontal line.
The line is now inserted. By default, it extends all the way from the left to the right margin.
Changing the line's properties
To change the appearance of the line, select the line by clicking on it and then right-click to open the context menu. Select the entry Line properties.
Tip: This command can also be chosen by double-clicking on the line.
The program displays a dialog box with the following options:
▪Width of line
| The width of horizontal lines is normally specified as a percentage of the page width. By default, the width is set to 100 percent; thus, the line extends all the way from the left to the right margin. If, for example, you change this setting to 50 percent, the line is shortened to half the page width. |
| Alternatively, you can enable the option Absolute and enter the desired width as a fixed value. |
▪Thickness
| Here, you can enter the desired line thickness in points. |
▪Justification
| Here, select how the line should be aligned: Left (at the left margin), Centered (in the middle of the page) or Right (at the right margin). |
▪Color
| Here, you can select the line's color. |
| In addition to the default colors offered here, you can define new colors at any time. For more information, see Document properties, Colors tab. |
▪3D effect
| If this option is enabled, the line is drawn with a 3D effect. |
| Tip: For lines that are only 1 pt thick, this is hardly noticeable. Thus, if you want to use this effect, you should increase the line thickness. |
▪Color of 3D effect
| Here, you can change the color of the 3D effect. |