:root {
            --primary: #7F5FFF;
            --secondary: #5F9FFF;
            --accent: #FF6B8B;
            font-family: 'Poppins', 'Segoe UI', sans-serif;
        }
        .containerr {
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            border-radius: 30px;
            padding: 40px;
            margin: 50px 20%;
            text-align: center;
        }
        h1 { color: var(--primary); font-size: 2.8em; margin-bottom: 40px; position: relative; }
        h1::after {
            content: '';
            position: absolute;
            bottom: -10px;
            left: 50%;
            transform: translateX(-50%);
            width: 30%;
            height: 3px;
            background: linear-gradient(90deg, transparent, var(--primary), transparent);
        }
        .config-panel { display: flex; gap: 20px; justify-content: center; margin-bottom: 30px; flex-wrap: wrap; }
        .input-group {
            background: rgba(255,255,255,0.9);
            border-radius: 20px;
            padding: 10px 20px;
            display: inline-flex;
            align-items: center;
            gap: 12px;
        }
        input, select { padding: 8px 15px; border: 2px solid rgba(127,95,255,0.2); border-radius: 12px; }
        textarea {
            width: 95%;
            height: 200px;
            padding: 25px;
            border: 2px solid rgba(127,95,255,0.2);
            border-radius: 20px;
            margin: 0 auto;
            display: block;
        }
        .button-container { display: flex; justify-content: center; gap: 15px; flex-wrap: wrap; margin: 30px 0; }
        button {
            background: linear-gradient(135deg, var(--primary), var(--secondary));
            color: white;
            border: none;
            padding: 12px 24px;
            border-radius: 40px;
            cursor: pointer;
            transition: 0.2s;
        }
        button:hover { transform: translateY(-2px); }
        .export-btn { background: linear-gradient(135deg, #2ecc71, #27ae60); }
        .save-btn { background: linear-gradient(135deg, #f39c12, #e67e22); }
        .reset-history-btn { background: linear-gradient(135deg, #e74c3c, #c0392b); }
        .history-export-btn { background: linear-gradient(135deg, #3498db, #2980b9); }
        .history-import-btn { background: linear-gradient(135deg, #9b59b6, #8e44ad); }
        .results-container { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px,1fr)); gap: 25px; margin-top: 40px; }
        .group-card {
            background: rgba(255,255,255,0.95);
            border-radius: 20px;
            padding: 20px;
            box-shadow: 0 8px 20px rgba(0,0,0,0.08);
            animation: fadeIn 0.5s;
        }
        @keyframes fadeIn { from { opacity:0; transform:translateY(20px); } to { opacity:1; transform:translateY(0); } }
        .group-number { color: var(--primary); font-size: 1.4em; font-weight: bold; margin-bottom: 15px; border-bottom: 2px solid var(--primary); display: inline-block; }
        .group-member { padding: 10px; margin: 8px 0; background: rgba(0,0,0,0.03); border-radius: 12px; transition: 0.2s; }
        .group-member:hover { transform: translateX(2px); background: rgba(127,95,255,0.1); }
        .empty-slot { color: #aaa; font-style: italic; }
        .history-section { margin-top: 50px; border-top: 2px dashed rgba(127,95,255,0.3); padding-top: 30px; }
        .history-table { width: 100%; border-collapse: collapse; background: rgba(255,255,255,0.8); border-radius: 16px; overflow: hidden; }
        .history-table th, .history-table td { border: 1px solid rgba(127,95,255,0.2); padding: 10px; text-align: center; }
        .history-table th { background: linear-gradient(135deg, var(--primary), var(--secondary)); color: white; }
        .file-input-label { background: linear-gradient(135deg, #9b59b6, #8e44ad); padding: 12px 24px; border-radius: 40px; color: white; cursor: pointer; display: inline-block; }
        input[type="file"] { display: none; }
        @media (max-width: 768px) {
            .containerr { margin: 15px; padding: 20px; }
            .config-panel { flex-direction: column; }
            .button-container { flex-direction: column; }
            button, .file-input-label { width: 100%; }
        }