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CSS

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HTML 

              
                <div class="page-wrapper">
    <div class="page-layout">
        <main class="demo-section main-content">
            <h1>Main Content</h1>
            <p>On a wide screen, this card looks correct.</p>
            
            <article class="card">
                <img class="card-image" src="https://placehold.co/600x400/22c55e/ffffff?text=Looks+Good" alt="Correctly laid out card">
                <div class="card-content">
                    <h2 class="card-title">Adaptive Card</h2>
                    <p class="card-description">My layout is based on the wide viewport.</p>
                    <button class="card-button">Learn More</button>
                </div>
            </article>
        </main>
        
        <aside class="demo-section sidebar">
            <h1>Sidebar</h1>
            <p>On a wide screen, this card's layout is broken.</p>
            
            <article class="card">
                <img class="card-image" src="https://placehold.co/600x400/ef4444/ffffff?text=Broken!" alt="Broken layout card">
                <div class="card-content">
                    <h2 class="card-title">Adaptive Card</h2>
                    <p class="card-description">My container is narrow, but the media query breaks my layout!</p>
                    <button class="card-button">Learn More</button>
                </div>
            </article>
        </aside>
    </div>
</div>
!

CSS 

              
                :root {
            --surface-color: #ffffff;
            --background-color: #f1f5f9;
            --primary-color: #4f46e5;
            --text-primary: #1e293b;
            --text-secondary: #64748b;
            --border-color: #e2e8f0;
        }

        body {
            font-family: 'Inter', system-ui, sans-serif;
            background-color: var(--background-color);
            color: var(--text-primary);
            margin: 0;
            padding: 2rem;
        }

        .page-wrapper {
            max-width: 1200px;
            margin: 0 auto;
        }

        .page-layout {
            display: grid;
            grid-template-columns: 1fr;
            gap: 2rem;
        }

        /* On wider screens, create a main content area and a sidebar */
        @media (min-width: 960px) {
            .page-layout {
                grid-template-columns: minmax(0, 2.5fr) minmax(0, 1fr);
            }
        }

        .demo-section h1 {
            font-size: 1.5rem;
            font-weight: 700;
            margin-top: 0;
            margin-bottom: 0.25rem;
            color: var(--text-primary);
        }

        .demo-section p {
            font-size: 1rem;
            color: var(--text-secondary);
            margin-top: 0;
        }

        /* 2. Enhanced Card Component Styles */
        .card {
            display: grid;
            grid-template-columns: 1fr; /* Default is single column */
            background-color: var(--surface-color);
            border-radius: 0.75rem; /* Softer corners */
            border: 1px solid var(--border-color);
            box-shadow: 0 1px 3px rgba(0,0,0,0.05), 0 1px 2px rgba(0,0,0,0.02);
            overflow: hidden;
            margin-top: 1.5rem;
        }

        .card-image {
            width: 100%;
            height: auto;
            display: block;
            aspect-ratio: 16 / 9;
            object-fit: cover;
        }

        .card-content {
            padding: 1.5rem;
        }

        .card-title {
            font-size: 1.25rem;
            font-weight: 700;
            margin: 0 0 0.5rem 0;
        }
        
        .card-description {
            color: var(--text-secondary);
            line-height: 1.6;
            margin: 0 0 1.5rem 0;
        }

        .card-button {
            display: inline-block;
            background-color: var(--primary-color);
            color: white;
            border: none;
            padding: 0.75rem 1.5rem;
            border-radius: 0.5rem;
            font-weight: 500;
            text-align: center;
            cursor: pointer;
            transition: background-color 0.2s ease;
        }
        
        .card-button:hover {
            background-color: #4338ca;
        }


        /* 3. THE BRITTLE MEDIA QUERY */
        /* This rule applies to BOTH cards when the viewport is > 960px,
           even though the sidebar card doesn't have enough space. */
        @media (min-width: 960px) {
            .card {
                grid-template-columns: 140px 1fr; /* Horizontal layout */
                align-items: center;
                gap: 0; /* Gaps handled by padding now */
            }

            .card-image {
                height: 100%;
            }

            /* Adjust padding for horizontal layout */
            .card-content {
                padding: 1.5rem;
            }
        }
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