.container-convert {
        max-width: 500px;
        margin: 40px auto;
        padding: 0 20px;
    }

    .converter-card {
        background: #ffffff;
        border-radius: 20px;
        box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
        padding: 30px;
        transition: transform 0.3s ease;
    }

    .converter-card:hover {
        transform: translateY(-5px);
    }

    .converter-card-header {
        color: #2c3e50;
        text-align: center;
        font-size: 1.5em;
        font-weight: 700;
        margin-bottom: 25px;
        letter-spacing: 0.5px;
    }

    .converter-card-header i {
        color: #4e888d;
        margin-right: 10px;
    }

    .form-group {
        margin-bottom: 20px;
        position: relative;
    }

    .form-group label {
        display: block;
        font-weight: 600;
        color: #2c3e50;
        margin-bottom: 8px;
        font-size: 0.95em;
    }

    .form-control {
        border-radius: 12px;
        border: 2px solid #e9ecef;
        font-size: 1em;
        width: 100%;
        transition: all 0.3s ease;
        background-color: #f8f9fa;
    }

    .form-control:focus {
        border-color: #4e888d;
        box-shadow: 0 0 0 3px rgba(78, 136, 141, 0.1);
        background-color: #ffffff;
        outline: none;
    }

    .btn-primary {
        background: linear-gradient(135deg, #4e888d 0%, #3a666b 100%) !important;
        border: none;
        border-radius: 12px;
        padding: 14px 20px;
        width: 100%;
        font-size: 1.1em;
        font-weight: 600;
        color: white;
        cursor: pointer;
        transition: all 0.3s ease;
        margin-top: 10px;
    }

    .btn-primary:hover {
        background: linear-gradient(135deg, #3a666b 0%, #4e888d 100%) !important;
        transform: translateY(-2px);
        box-shadow: 0 5px 15px rgba(78, 136, 141, 0.2);
    }

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

    .result {
        margin-top: 25px;
        padding-top: 20px;
        border-top: 2px dashed #e9ecef;
    }

    .result h2 {
        font-size: 1.2em;
        color: #2c3e50;
        font-weight: 600;
        text-align: center;
        margin: 0;
    }

    .text-danger {
        font-size: 0.85em;
        color: #dc3545;
        margin-top: 5px;
        padding-left: 5px;
    }

    @media (max-width: 576px) {
        .container-convert {
            margin: 20px auto;
        }

        .converter-card {
            padding: 20px;
        }

        .converter-card-header {
            font-size: 1.3em;
        }
    }