10. A system comprising: a display; one or more input devices; one or more processors; and a memory coupled to the one or more processors and configured for storing instructions, which, when executed by the one or more processors, causes the one or more processors to perform operations comprising: displaying, on the display, a first text string with a first type style and a second text string with a second type style, wherein the first type style is different than the second type style; the first text string is displayed proximate to the second text string on the display with a first spatial arrangement that is determined based at least in part on the first type style and the second type style; after displaying the first text string and the second text string on the display, receiving, via the one or more input devices, input that changes a font size of the first text string and changes the respective font size of the second text string; in response to receiving the input, dynamically adjusting one or more font metrics that determine the special arrangement of text in accordance with text layout rules based on the first type style and the second type style; and displaying, on the display, the first text string and the second text string with the respective font size changed and with a second spatial arrangement that is determined based on the first type style, the second type style and the dynamically adjusted one or more font metrics.
10. A system comprising: a display; one or more input devices; one or more processors; and a memory coupled to the one or more processors and configured for storing instructions, which, when executed by the one or more processors, causes the one or more processors to perform operations comprising: displaying, on the display, a first text string with a first type style and a second text string with a second type style, wherein the first type style is different than the second type style; the first text string is displayed proximate to the second text string on the display with a first spatial arrangement that is determined based at least in part on the first type style and the second type style; after displaying the first text string and the second text string on the display, receiving, via the one or more input devices, input that changes a font size of the first text string and changes the respective font size of the second text string; in response to receiving the input, dynamically adjusting one or more font metrics that determine the special arrangement of text in accordance with text layout rules based on the first type style and the second type style; and displaying, on the display, the first text string and the second text string with the respective font size changed and with a second spatial arrangement that is determined based on the first type style, the second type style and the dynamically adjusted one or more font metrics. 16. The system of claim 10 , wherein at least one of the text layout rules specifies an amount of leading between baselines of text strings.