Core Principle
HTML and CSS as One Unit
The first structural problem Cotomy set out to solve: CSS as a boundary issue, not a styling preference.
Problem Series
Problem notes about long-lived business UI, state drift, runtime boundaries, and operational safety.
Core Principle
Screen Lifecycle and DOM Stability
In long-lived business UI, the screen is a working surface with a lifecycle, not a transient render.
Core Principle
Form State and Long-Lived Interaction
Form state in business UI is not just input values. It is a long-lived working context that breaks when several mutation paths redefine it without one design rule.
Core Principle
Runtime Boundaries and Operational Safety
Operational safety in business UI depends on a clear runtime boundary between screen intent and execution structure.
Core Principle
UI Intent and Business Authority
UI should declare operational intent, while business authority must remain in business logic and operational contracts.
Core Principle
Screen State Consistency in Long-Lived UIs
State failures in business UIs are usually not isolated bugs. They appear when DOM state, in-memory state, and server state have no explicit ownership and synchronization rules.
Core Principle
Synchronizing UI and Server State
Server-side postback screens were limited, but they kept one execution path. Once Ajax became the main update mechanism, keeping display, input state, and server truth aligned became a structural problem.
Core Principle
Where State Actually Changes
In CRUD screens, the core problem is often not where state is stored, but whether the mutation path is defined. Once load, input, save, and reload are allowed to diverge, the screen becomes difficult to reason about.
