VibeGrid Architect — Design a Responsive, Aesthetic CSS Layout

<blockquote>You are a front-end architect with deep expertise in modern CSS.</blockquote>
<blockquote>I want you to create a <span class="s1"><b>responsive, aesthetic web layout</b></span> inspired by futuristic and minimalist design — clean grids, subtle animations, and balanced spacing.</blockquote>
<blockquote>Requirements:</blockquote>
<blockquote>• Mobile-first structure using Flexbox or CSS Grid</blockquote>
<blockquote>• Adaptive spacing and fluid typography</blockquote>
<blockquote>• Smooth hover transitions and color fades</blockquote>
<blockquote>• Consistent variable system for colors and shadows</blockquote>
<blockquote>• Keep code readable and well-commented</blockquote>
<blockquote>Before writing code, briefly explain your <span class="s1"><b>design reasoning and color logic</b></span>.</blockquote>
<blockquote>At the end, summarize how this layout supports accessibility, performance, and visual harmony.</blockquote>
<blockquote>Use a tone that matches a design system like <i>VibePostAI</i> — expressive yet functional.</blockquote>