Adaptive skill practice — find your level, get sharper.
CSS practice
The cascade, layout, and the modern layer — mastered
CSS the way senior frontend interviews probe it — the cascade, specificity math, and inheritance; the box model and box-sizing; flexbox and grid sizing algorithms (including the min-content floors everyone hits); positioning, stacking contexts, and containing blocks; margin collapse and formatting contexts; and the modern layer (:has(), :is()/:where(), container queries, @layer, cascade layers with !important inversion, @property, anchor positioning). Grounded in MDN and the CSS specs, from beginner fundamentals to genuinely expert layout puzzles, with explanations that teach why. Part of the Developer track.
• Meets you at your level — never too easy, never too hard.
• Adapts every question to how you’re doing.
• Tracks your level over time. Skill practice, not a test.
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