:root {
            --primary-color: #2c3e50;
            --accent-color: #3498db;
            --bg-color: #f8f9fa;
            --card-bg: #ffffff;
            --text-color: #333;
        }
        body { 
            font-family: 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Microsoft YaHei', sans-serif; 
            background-color: var(--bg-color); 
            color: var(--text-color);
            line-height: 1.7;
            margin: 0;
            }
        .page-container {
            max-width: 1100px;
            margin: 40px auto;
            padding: 40px;
            background: var(--card-bg);
            box-shadow: 0 10px 30px rgba(0,0,0,0.05);
            border-radius: 12px;
        }
        h1 { 
            color: var(--primary-color); 
            text-align: center; 
            margin-bottom: 30px; 
            font-weight: 700;
            border-bottom: 3px solid var(--accent-color);
            display: inline-block;
            padding-bottom: 10px;
        }
        .header-wrapper { text-align: center; margin-bottom: 40px; }
        
        .back-btn {
            display: inline-flex;
            align-items: center;
            padding: 10px 20px;
            background-color: var(--primary-color);
            color: white !important;
            text-decoration: none;
            border-radius: 6px;
            font-weight: 500;
            transition: all 0.3s ease;
            border: none;
            cursor: pointer;
            margin-bottom: 20px;
        }
        .back-btn:hover {
            background-color: var(--accent-color);
            transform: translateX(-5px);
        }

.sim-wrapper {
    display: flex !important;
    justify-content: center !important;
    align-items: flex-start !important;
    width: 100% !important;
    margin: 20px 0 !important;
    overflow: visible !important;
}

#total {
    width: 600px;
    height: 420px;
    position: relative;
    background: white;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    flex-shrink: 0;
}

#canvas {
    position: absolute;
    left: 0;
    top: 0;
    width: 600px;
    height: 350px;
}

#panel {
    position: absolute;
    left: 0;
    top: 350px;
    width: 600px;
    height: 70px;
    background: #f8fafc;
    border-top: 1px solid #e2e8f0;
    padding: 10px 16px;
    box-sizing: border-box;
    display: flex !important;
    flex-direction: column !important;
    align-items: center !important;
    justify-content: center !important;
}

#panel div, #panel span, #panel input, #panel button {
    position: static !important;
}

.input-row {
    display: flex !important;
    align-items: center !important;
    gap: 10px !important;
}

input[type="text"] {
    width: 60px !important;
    padding: 6px !important;
    border-radius: 4px !important;
    border: 1px solid #cbd5e1 !important;
    text-align: center !important;
    font-size: 1rem !important;
}

/* Mobile full-width adaptation */
@media (max-width: 600px) {
    .container { margin: 0 !important; padding: 0 !important; }
    .card { padding: 15px 10px !important; border-radius: 0 !important; }
    .sim-wrapper { margin: 10px 0 !important; }
}