:root {
            --primary-bg: #0f172a;
            --glass: rgba(255, 255, 255, 0.05);
            --glass-border: rgba(255, 255, 255, 0.1);
            --primary-color: #4ade80; /* Green */
            --secondary-color: #fb923c; /* Orange */
            --tertiary-color: #60a5fa; /* Blue */
            --quaternary-color: #a78bfa; /* Purple */
        }

        body {
            margin: 0;
            font-family: 'Inter', sans-serif;
            background-color: var(--primary-bg);
            color: white;
            line-height: 1.6;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 60px 20px;
        }

        .header-section {
            text-align: center;
            margin-bottom: 50px;
        }

        .header-section h1 { font-size: 2.5rem; margin-bottom: 10px; }
        .header-section p { opacity: 0.7; font-size: 1.1rem; max-width: 600px; margin: 0 auto; }

        .filter-container {
            display: flex;
            justify-content: center;
            gap: 15px;
            margin-bottom: 40px;
            flex-wrap: wrap;
        }

        .filter-btn {
            padding: 10px 20px;
            border-radius: 99px;
            border: 1px solid var(--glass-border);
            background: var(--glass);
            color: white;
            cursor: pointer;
            transition: 0.3s;
            font-weight: 500;
        }

        .filter-btn.active, .filter-btn:hover {
            background: #fff;
            color: #000;
        }

        .cluster-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
            gap: 25px;
        }

        .cluster-card {
            background: var(--glass);
            backdrop-filter: blur(10px);
            border: 1px solid var(--glass-border);
            border-radius: 20px;
            padding: 30px;
            transition: 0.3s;
            position: relative;
            overflow: hidden;
            color: white;
            display: block;
            cursor: pointer;
        }

        .cluster-card:hover {
            transform: translateY(-8px);
            background: #a78bfa; /* Your requested purple color */
            border-color: rgba(255, 255, 255, 0.4);
            color: white; /* Keeps text readable against the purple */
        }
        .icon-box { font-size: 2.5rem; margin-bottom: 20px; display: block; }

        .sector-tag {
            font-size: 0.7rem;
            text-transform: uppercase;
            font-weight: 700;
            padding: 4px 10px;
            border-radius: 5px;
            margin-bottom: 10px;
            display: inline-block;
        }

        .tag-primary { background: rgba(74, 222, 128, 0.2); color: #4ade80; }
        .tag-secondary { background: rgba(251, 146, 60, 0.2); color: #fb923c; }
        .tag-tertiary { background: rgba(96, 165, 250, 0.2); color: #60a5fa; }
        .tag-quaternary { background: rgba(167, 139, 250, 0.2); color: #a78bfa; }

        .cluster-card h3 { margin: 10px 0; font-size: 1.3rem; }
        .cluster-card p { font-size: 0.9rem; opacity: 0.7; margin-bottom: 20px; height: 3.6em; overflow: hidden; }

        .path-count {
            font-size: 0.8rem;
            font-weight: bold;
            display: flex;
            align-items: center;
            gap: 5px;
            color: rgba(255, 255, 255, 0.5);
        }

        /* Modal Styling */
        .modal-overlay {
            position: fixed;
            top: 0; left: 0; width: 100%; height: 100%;
            background: rgba(0, 0, 0, 0.85);
            display: none;
            align-items: center;
            justify-content: center;
            z-index: 1000;
            backdrop-filter: blur(10px);
        }

        .modal-content {
            background: #1e293b;
            width: 90%;
            max-width: 800px;
            border-radius: 24px;
            padding: 40px;
            position: relative;
            border: 1px solid var(--glass-border);
            max-height: 85vh;
            overflow-y: auto;
        }

        .close-modal {
            position: absolute;
            top: 20px; right: 20px;
            font-size: 2rem;
            cursor: pointer;
            color: #94a3b8;
        }

        .path-list {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
            gap: 15px;
            margin-top: 30px;
        }

        .path-link {
            background: rgba(255, 255, 255, 0.05);
            padding: 15px;
            border-radius: 12px;
            text-decoration: none;
            color: #cbd5e1;
            font-size: 0.95rem;
            transition: 0.2s;
            border: 1px solid transparent;
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .path-link:hover {
            background: rgba(255, 255, 255, 0.1);
            border-color: var(--quaternary-color);
            color: white;
        }

        @media (max-width: 768px) {
            .header-section h1 { font-size: 2rem; }
            .cluster-grid { grid-template-columns: 1fr; }
        }