:root {
            --bg-color-light: #e0e7f2;
            --card-bg-light: #ffffff;
            --text-color-light: #333333;
            --primary-color: #6a4fe6;
            --bubble-color: #e6e9f0;
            --popped-color: #d1d5db;
            --border-color-light: #d0d5da;
            --shadow-color-light: rgba(0, 0, 0, 0.1);
        }

        body.dark-mode {
            --bg-color-light: #16162a;
            --card-bg-light: #1a1a2e;
            --text-color-light: #c0c0d0;
            --primary-color: #a78bfa;
            --bubble-color: #33364f;
            --popped-color: #212338;
            --border-color-light: #3a3a5a;
            --shadow-color-light: rgba(0, 0, 0, 0.4);
        }

        body {
            background-color: var(--bg-color-light);
            color: var(--text-color-light);
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
            margin: 0;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
            overflow-x: hidden;
            user-select: none;
            padding: 20px;
            box-sizing: border-box;
            transition: background-color 0.3s, color 0.3s;
        }
        
        h1 {
            font-size: clamp(2em, 5vw, 2.5em);
            text-shadow: 2px 2px 4px var(--shadow-color-light);
            margin-bottom: 20px;
            color: var(--primary-color);
        }

        .bubble-grid-container {
            position: relative;
            width: 100%;
            max-width: 800px;
        }

        .bubble-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(40px, 1fr));
            gap: 5px;
            padding: 10px;
            background-color: var(--card-bg-light);
            border-radius: 15px;
            box-shadow: 0 10px 30px var(--shadow-color-light);
            width: 100%;
        }

        .bubble {
            width: 100%;
            padding-top: 100%; /* Makes the bubble a perfect square */
            position: relative;
            background-color: var(--bubble-color);
            border-radius: 50%;
            border: 2px solid var(--border-color-light);
            box-shadow: inset 0 3px 5px rgba(0, 0, 0, 0.2), 0 2px 4px rgba(0, 0, 0, 0.1);
            cursor: pointer;
            transition: transform 0.1s, box-shadow 0.1s, background-color 0.3s;
        }
        .bubble:hover {
            transform: scale(1.05);
        }
        .bubble.popped {
            background-color: var(--popped-color);
            box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.3), 0 1px 2px rgba(0, 0, 0, 0.1);
            transform: scale(0.95);
            cursor: default;
        }
        .theme-toggle {
            position: absolute;
            top: -50px;
            right: 10px;
            background: var(--card-bg-light);
            border: 1px solid var(--border-color-light);
            border-radius: 50%;
            width: 45px;
            height: 45px;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            box-shadow: 0 2px 4px var(--shadow-color-light);
            transition: background-color 0.3s, transform 0.2s;
            z-index: 10;
        }
        .theme-toggle:hover {
            background-color: var(--bg-color-light);
            transform: scale(1.05);
        }
        .theme-toggle .material-icons {
            font-size: 24px;
            color: var(--text-color-light);
            transition: color 0.3s;
        }

        /* --- Explore More Section --- */
        .resources-section {
            width: 100%;
            max-width: 800px;
            margin-top: 30px;
            padding-top: 20px;
            border-top: 1px solid var(--border-color-light);
            text-align: center;
        }
        .resources-section h3 {
            color: var(--primary-color);
            margin-bottom: 15px;
            font-size: clamp(1em, 4vw, 1.5em);
        }
        .resources-list {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 15px;
            list-style: none;
            padding: 0;
        }
        .resources-list a {
            padding: 10px 15px;
            border-radius: 8px;
            background-color: var(--card-bg-light);
            border: 1px solid var(--border-color-light);
            text-decoration: none;
            color: var(--text-color-light);
            transition: background-color 0.2s, transform 0.2s;
            display: flex;
            align-items: center;
            font-weight: bold;
        }
        .resources-list a:hover {
            transform: translateY(-2px);
            background-color: var(--primary-color);
            color: white;
        }
        .resources-list a:hover .material-icons {
             color: white;
        }
        .resources-list a .material-icons {
            margin-right: 8px;
            color: var(--primary-color);
            transition: color 0.2s;
        }