How did Tibetan and Burmese writing systems develop from Indic writing traditions?

The Tibetan and Burmese writing systems are both derived from the Indic writing traditions, specifically tracing their lineage back to the Brahmi script of ancient India.12

The Tibetan Script

The Tibetan writing system was developed in the 7th century CE. It evolved from the Gupta script, a northern derivative of Brahmi. The invention of the Tibetan script was heavily influenced by cultural contacts with Buddhist regions in northwestern India, Kashmir, and Nepal. Because the Tibetan language differed significantly from these Indic languages, the script was adapted to suit Tibetan phonology, leading to the creation of a specialized literary language used primarily for translating Buddhist texts.3214

The Burmese Script

The Burmese writing system, which dates from the 11th century, also shares an Indic origin. While the Tibetan script descended from the northern Gupta branch, the Burmese system is thought to be derived from the Mon script of Southeast Asia. The Mon script itself is a descendant of the southern varieties of the Brahmi script, which spread throughout Southeast Asia alongside the expansion of Buddhism.213