* {
            margin: 0;
            padding: 0;
           
        }

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: linear-gradient(135deg, #1B3B5F, #465e78, #1B3B5F);



        }
        .main-container{
                flex: 1;
    max-width: 800px;
    margin: 130px auto 2rem auto; /* 120px en haut */
    padding: 0 2rem;
        }

        .header {
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            border-bottom: 1px solid rgba(255, 255, 255, 0.2);
            padding: 1rem 0;
            
        }

        .header-content {
            max-width: 1200px;
          
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0 2rem;
        }


        .close-button {
            background: none;
            border: none;
            padding: 0.5rem;
            border-radius: 50%;
            cursor: pointer;
            transition: all 0.3s ease;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .close-button:hover {
            background: rgba(255, 0, 0, 0.1);
        }

        .container {
            flex: 1;
            max-width: 800px;
            margin: 2rem auto;
            padding: 0 2rem;
        }

        .calculator-card {
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            border-radius: 20px;
            padding: 2rem;
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
            border: 1px solid rgba(255, 255, 255, 0.2);
        }

        .calculator-title {
            text-align: center;
            color: #333;
            margin-bottom: 2rem;
            font-size: 2rem;
            font-weight: bold;
        }

        .form-group {
            margin-bottom: 1.5rem;
        }

        .form-group label {
            display: block;
            margin-bottom: 0.5rem;
            font-weight: 600;
            color: #333;
        }

        .form-group select,
        .form-group input {
            width: 100%;
            padding: 0.75rem;
            border: 2px solid #e1e1e1;
            border-radius: 10px;
            font-size: 1rem;
            transition: all 0.3s ease;
            background: white;
        }

        .form-group select:focus,
        .form-group input:focus {
            outline: none;
            border-color: #b88341;
            box-shadow: 0 0 0 3px rgba(78, 186, 169, 0.1);
        }

        .calculate-btn {
            width: 100%;
            background: linear-gradient(135deg, #4e80ba, #17395e);
            color: white;
            border: none;
            padding: 1rem;
            border-radius: 10px;
            font-size: 1.1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            margin: 1rem 0;
        }

        .calculate-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 20px rgba(78, 186, 169, 0.3);
        }

        .results {
            background: linear-gradient(135deg, #f8f9fa, #e9ecef);
            border-radius: 15px;
            padding: 1.5rem;
            margin-top: 2rem;
            border-left: 4px solid #4ebaa9;
        }

        .result-row {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0.5rem 0;
            border-bottom: 1px solid #dee2e6;
        }

        .result-row:last-child {
            border-bottom: none;
            font-weight: bold;
            font-size: 1.1rem;
            margin-top: 0.5rem;
        }

        .tva-info {
            background: rgba(78, 186, 169, 0.1);
            border-radius: 10px;
            padding: 1rem;
            margin-top: 1rem;
            border-left: 4px solid #4ebaa9;
        }

        .tva-info h4 {
            color: #4ebaa9;
            margin-bottom: 0.5rem;
        }

        .tva-info p {
            color: #666;
            font-size: 0.9rem;
            line-height: 1.4;
        }

        .footer {
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            border-top: 1px solid rgba(255, 255, 255, 0.2);
            text-align: center;
            padding: 1.5rem;
            color: #666;
            margin-top: auto;
        }

        .footer p {
            margin: 0.25rem 0;
        }

        .grid-container {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 1rem;
        }

        @media (max-width: 768px) {
            .grid-container {
                grid-template-columns: 1fr;
            }
            
            .header-content {
                padding: 0 1rem;
            }
            
            .nav {
                gap: 1rem;
            }
            
            .container {
                padding: 0 1rem;
            }
        }

        .error-message {
            color: #dc3545;
            font-size: 0.9rem;
            margin-top: 0.5rem;
        }

        .warning-message {
            background: rgba(255, 193, 7, 0.1);
            border-left: 4px solid #ffc107;
            padding: 1rem;
            border-radius: 10px;
            margin-top: 1rem;
        }