Wide YouTube channel banner, 16:9, for a mystery riddle channel. Cozy noir detective café at night: a rain-streaked window, a desk with a coffee cup, a magnifying glass, an evidence board with red string and four silhouetted suspects marked 1 to 4. Palette of deep navy, warm amber lamp light and touches of red. Stylized illustration with soft cinematic shadows and a playful, mysterious mood. Keep the key elements inside the central safe area. Leave an empty space in the center for the channel name. Tagline area: "Spot the clue. Find the culprit." No other text.
