Design a Hard Magic System With Internal Logic

You want magic that behaves like a system, not a get-out-of-jail card. Name the source, sound, heat, memory, and this defines its cost, scope and limits so characters and readers can actually learn the rules. Good for fantasy writers building a hard magic system where the constraints generate the drama.

Help me design a hard magic system for a fantasy world. The magic must follow strict, discoverable rules that characters and readers can learn.

The core source of magic is: {MAGIC_SOURCE} (e.g., 'sound vibrations', 'metabolic heat', 'emotional memory').

For this magic system, define:
- The Rule of Cost: what does using magic take from the practitioner (physical, psychological, or social)?
- The Rule of Scope: what can magic never do, no matter how skilled the user?
- The Rule of Mastery: how does someone become more powerful, and what does the learning curve look like?
- The Rule of Detection: can bystanders tell when magic is being used, and how?
- One systemic consequence: how has the existence of this magic shaped law, warfare, or trade over centuries?

Be specific. Avoid vague 'it depends on the user' answers. Every rule should create at least one interesting story problem.