:root {
            --primary: #4a90e2;
            --primary-dark: #357abd;
            --success: #34c759;
            --warning: #ff9500;
            --danger: #ff3b30;
            --surface: #ffffff;
            --surface-elevated: #f8f9fa;
            --text-primary: #1a1a1a;
            --text-secondary: #666666;
            --border: #e1e4e8;
        }

        .header-section {
            max-width: 800px;
            margin: 2rem auto;
            padding: 2rem;
            background: var(--surface-elevated);
            border-radius: 12px;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            text-align: center;
        }

        .header-section h1 {
            font-size: 2.5rem;
            margin-bottom: 1rem;
            color: var(--text-primary);
        }

        .header-section p {
            font-size: 1.1rem;
            line-height: 1.6;
            color: var(--text-secondary);
            margin-bottom: 1.5rem;
        }

        .controls {
            max-width: 800px;
            margin: 2rem auto;
            padding: 2rem;
            background: var(--surface);
            border-radius: 12px;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 1.5rem;
        }

        .control-group {
            display: flex;
            flex-direction: column;
            gap: 0.5rem;
        }

        .control-group label {
            font-weight: 500;
            color: var(--text-primary);
        }

        .input-control {
            width: 100%;
            padding: 0.75rem;
            border: 2px solid var(--border);
            border-radius: 8px;
            font-size: 1rem;
            transition: all 0.2s ease;
        }

        .input-control:focus {
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
            outline: none;
        }

        .update-btn {
            width: 100%;
            padding: 1rem;
            background: linear-gradient(135deg, var(--primary), var(--primary-dark));
            color: white;
            border: none;
            border-radius: 8px;
            font-size: 1.1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.2s ease;
            grid-column: 1 / -1;
        }

        .update-btn:hover {
            transform: translateY(-1px);
            box-shadow: 0 4px 12px rgba(74, 144, 226, 0.2);
        }

        .update-btn:active {
            transform: translateY(0);
        }

        .visualization {
            max-width: 1200px;
            margin: 2rem auto;
            padding: 2rem;
            background: var(--surface);
            border-radius: 12px;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
        }

        .grid {
            display: grid;
            gap: 4px;
            margin: 2rem 0;
            justify-content: center;
        }

        .time-block {
            width: 100%;
            aspect-ratio: 1;
            background: var(--border);
            border-radius: 4px;
            transition: all 0.3s ease;
        }

        .time-block.lived {
            background: var(--primary);
        }

        .time-block:hover {
            transform: scale(1.1);
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
        }

        .stats {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 1.5rem;
            margin-top: 2rem;
        }

        .stat-box {
            background: var(--surface-elevated);
            padding: 1.5rem;
            border-radius: 8px;
            text-align: center;
        }

        .stat-value {
            font-size: 2rem;
            font-weight: 700;
            color: var(--text-primary);
            margin-bottom: 0.5rem;
        }

        .stat-label {
            font-size: 1rem;
            color: var(--text-secondary);
        }

        .stat-value.highlight {
            color: var(--warning);
        }

        @media (max-width: 768px) {
            .header-section {
                padding: 1.5rem;
                margin: 1rem;
            }

            .header-section h1 {
                font-size: 2rem;
            }

            .controls,
            .visualization {
                margin: 1rem;
                padding: 1.5rem;
            }

            .grid {
                gap: 2px;
            }

            .time-block {
                min-width: 12px;
                min-height: 12px;
            }
        }