/* --- CORE CONFIGURATION (Adjust these variables in your target project) --- */
        :root {
            /* Branding Colors */
            --primary-color: #099b29ff; /* Green */
            --secondary-color: #02112bff; /* Dark Blue/Navy */
            --color-light-text: #e2e8f0; /* Off-White/Light Gray for text on dark backgrounds */
            --color-red: #ef4444; /* Accent red for close button */
            --light-card: #f9fafb; /* Background of the modal content */
        }
        
        /* Base Styling for Reusability 
        body {
            font-family: 'Inter', sans-serif;
            margin: 0;
            padding: 0;
            background-color: #f0f0f0; /* Neutral background for testing 
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
        }
*/
        /* --- Custom Premium Classes (Kept minimal for button effect) --- */
        .pop-button {
            transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
        }
        .pop-button:hover {
            transform: translateY(-2px) scale(1.02);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
        }
        .premium-gradient {
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
        }
        
        /* --- Pop-up Advertisement Styling --- */
        
        /* 1. Overlay (The full-screen dark backdrop) */
        .ad-popup-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0, 0, 0, 0.4); 
            display: none; /* Hidden by default, toggled by JS */
            justify-content: center;
            align-items: center;
            z-index: 99999;
            -webkit-backdrop-filter: blur(1px);
            backdrop-filter: blur(1px);
            opacity: 0;
            transition: opacity 0.3s ease;
        }

        .ad-popup-overlay.visible {
            display: flex;
            opacity: 1;
        }

        /* 2. Container (The modal itself) */
        .ad-popup-container {
            position: relative;
            max-width: 550px; 
            width: 90%;
            background-color: var(--light-card);
            border-radius: 1.5rem;
            overflow: hidden;
            box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
            z-index: 100000;
            /* Springy animation for entrance */
            transform: scale(0.7); 
            transition: transform 0.4s cubic-bezier(0.68, -0.55, 0.27, 1.55);
        }

        .ad-popup-overlay.visible .ad-popup-container {
            transform: scale(1);
        }

        /* 3. Close Button */
        .ad-popup-close {
            position: absolute;
            top: 0.5rem;
            right: 0.5rem;
            background-color: var(--secondary-color);
            color: var(--light-card);
            border: 2px solid var(--light-card);
            font-size: 1.5rem;
            font-weight: 700;
            width: 2.5rem;
            height: 2.5rem;
            line-height: 1;
            border-radius: 50%;
            cursor: pointer;
            z-index: 10;
            opacity: 0.9;
            transition: background-color 0.3s, opacity 0.3s, transform 0.2s;
        }

        .ad-popup-close:hover {
            background-color: var(--color-red);
            opacity: 1;
            transform: rotate(90deg) scale(1.1);
        }

        /* 4. Image/Content Box */
        .ad-content-image {
            position: relative;
            width: 100%;
            /* Forces a 1:1 aspect ratio for the image container */
            padding-bottom: 100%; 
            overflow: hidden;
        }

        .ad-content-image img {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        /* 5. Action Bar Overlay (Bottom CTA strip) */
        .ad-action-bar-overlay {
            position: absolute;
            bottom: 0;
            left: 0;
            right: 0;
            padding: 1rem 1.5rem;
            background: rgba(2, 17, 43, 0.9); /* Semi-transparent dark blue */
            color: var(--color-light-text);
            display: flex;
            justify-content: space-between;
            align-items: center;
            gap: 1rem;
        }

        .ad-bar-text {
            font-size: 1.1rem;
            font-weight: 600;
            margin: 0;
        }

        /* 6. CTA Button */
        .ad-content-button {
            flex-shrink: 0;
            padding: 0.75rem 1.5rem;
            color: var(--color-light-text);
            font-weight: 700;
            text-decoration: none;
            border-radius: 0.5rem;
            display: flex;
            align-items: center;
            box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
            text-shadow: 0 1px 1px rgba(0, 0, 0, 0.2);
        }

        /* Responsive adjustments for Action Bar (Mobile Stack) */
        @media (max-width: 600px) {
            .ad-action-bar-overlay {
                flex-direction: column;
                align-items: stretch;
                text-align: center;
            }
            .ad-bar-text {
                font-size: 1rem;
                margin-bottom: 0.5rem;
            }
            .ad-content-button {
                justify-content: center;
            }
            .ad-popup-container {
                border-radius: 1rem;
            }
        }