.converter-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;
    max-width: 700px;
    margin: 20px auto;
    background-color: #f9f9f9;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.converter-container h2 {
    color: #333;
    margin-bottom: 25px;
    text-align: center;
    font-size: 1.8em;
}

.input-group {
    width: 100%;
    margin-bottom: 20px;
    text-align: center;
}

.input-group h3 {
    color: #555;
    margin-bottom: 10px;
    font-size: 1.2em;
}

.input-group input[type="number"],
.input-group select {
    width: calc(100% - 20px); /* Adjust for padding */
    padding: 10px;
    margin-top: 5px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1.1em;
    box-sizing: border-box; /* Include padding in width */
}

.swap-button-container {
    margin: 20px 0;
    text-align: center;
}

#swapUnitsBtn {
    padding: 10px 20px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1em;
    transition: background-color 0.3s ease;
}

#swapUnitsBtn:hover {
    background-color: #0056b3;
}

.result-box {
    margin-top: 15px;
    padding: 15px;
    background-color: #e0f7fa; /* Light blue background for visual effect */
    border: 1px solid #b2ebf2; /* Slightly darker border */
    border-radius: 8px;
    font-size: 1.6em;
    font-weight: bold;
    color: #00796b; /* Darker text for contrast */
    text-align: center;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.15), 0 1px 0 rgba(255, 255, 255, 0.5); /* 3D effect */
    word-wrap: break-word; /* Ensure long results wrap */
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .converter-container {
        padding: 15px;
        margin: 15px auto;
    }

    .converter-container h2 {
        font-size: 1.5em;
    }

    .input-group h3 {
        font-size: 1em;
    }

    .input-group input[type="number"],
    .input-group select {
        font-size: 1em;
        padding: 8px;
    }

    #swapUnitsBtn {
        padding: 8px 15px;
        font-size: 0.9em;
    }

    .result-box {
        font-size: 1.4em;
        padding: 12px;
    }
}

@media (max-width: 480px) {
    .converter-container {
        padding: 10px;
        margin: 10px auto;
    }
    .input-group input[type="number"],
    .input-group select {
        width: 100%; /* Full width on smaller screens */
    }
}