“PRIME”是使用 FontVibe AI 创作的3D 立体粗体文字效果。厚重的方块大写字母带深度挤出，每个字母一种亮面糖果色，顶光让高光滚过圆润边角，彩色倒影落在地面上。

Massive chunky 3D block letters with heavyweight extruded presence — thick uniform extrusion depth of 50-60% of letter height. Front face finished in ultra-glossy lacquer, catching directional key light with natural specular reflections that graduate from bright highlight to deep saturated color — the surface quality of hard candy coating or high-gloss toy paint. Side extrusion planes in a noticeably darker shade of the same hue, creating crisp face-to-depth contrast that reads immediately as three-dimensional volume. Adjacent letters each carry a different vivid saturated color, maximizing chromatic contrast across the word — no two adjacent letters share the same hue family. Hard sharp corner edges where face meets extrusion, no beveling. Long dramatic cast shadows at consistent 45-degree angle, shadow depth approximately 40-50% of letter height. Strong directional key light from upper left. Bold, high-contrast, maximum visual impact. A smartphone held in hand showing the YouTube app interface — phone screen bright in a slightly dim room, natural hand holding position. The YouTube home feed on screen shows a video thumbnail prominently: "PRIME" as the video title in massive colorful 3D candy-surface block letters — P cherry red, R electric blue, I sunshine yellow, M lime green, E hot orange — filling 70% of the thumbnail width over a vibrant gradient background. Ultra-glossy letters with full 3D depth visible on the small screen. Phone and screen are sharp focal point. Realistic product mockup quality — 16:9 mobile content scene.