/* Base styles and color scheme */
:root {
    --bg-color: #2c3e50;
    --btn-color: #ecf0f1;
    --btn-hover-color: #bdc3c7;
    --text-color: #34495e;
    --highlight-color: #3498db;
    --border-radius: 10px;
    --box-shadow: 0px 4px 8px rgba(0, 0, 0, 0.2);
}

/* Body and basic styling */
body {
    background-color: var(--bg-color);
    font-family: Arial, sans-serif;
    color: var(--btn-color);
    margin: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
}

.flex-container {
    display: flex;
    flex-direction: row;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 20px;
}

.flex-container-column {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 10px;
}

/* Button and div styling */
.flex-container>div,
.flex-container-column>div {
    background-color: var(--btn-color);
    color: var(--text-color);
    border-radius: var(--border-radius);
    padding: 20px;
    font-size: 24px;
    font-weight: bold;
    text-align: center;
    box-shadow: var(--box-shadow);
    transition: transform 0.2s ease, background-color 0.3s ease;
    cursor: pointer;
    flex: 1;
    /* Allow buttons to grow and fill available space */
}

/* Hover and active effects */
.flex-container>div:hover,
.flex-container-column>div:hover {
    background-color: var(--btn-hover-color);
    transform: scale(1.05);
}

.flex-container>div:active,
.flex-container-column>div:active {
    transform: scale(0.95);
    background-color: var(--highlight-color);
    color: #fff;
}

/* Input field styling */
#channel-input input {
    width: 100%;
    max-width: 300px;
    height: 50px;
    font-size: 18px;
    text-align: center;
    border: none;
    border-radius: var(--border-radius);
    padding: 10px;
    box-shadow: var(--box-shadow);
    transition: box-shadow 0.3s ease;
}

#channel-input input:focus {
    outline: none;
    box-shadow: 0px 4px 12px rgba(0, 123, 255, 0.4);
}

/* Cross-browser compatibility for hiding spinner arrows */
#channel-input input[type="number"] {
    appearance: textfield;
    /* Standard property */
    -webkit-appearance: none;
    /* WebKit browsers (Chrome, Safari, Edge) */
    -moz-appearance: textfield;
    /* Firefox */
}

/* Explicitly remove outer and inner spin buttons in WebKit browsers */
#channel-input input[type="number"]::-webkit-outer-spin-button,
#channel-input input[type="number"]::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

/* Numpad specific styles */
#numpad {
    display: flex;
    flex-direction: column;
    gap: 5px;
    /* Reduced gap between rows in the numpad */
}

#numpad div {
    display: flex;
    /* Use flex for rows */
    justify-content: center;
    /* Center buttons horizontally */
    gap: 10px;
    /* Space between buttons */
    flex-wrap: nowrap;
    /* Prevent wrapping to keep buttons in one row */
}

/* Center the number-0 button */
#number-0 {
    flex: 1;
    /* Allow the button to grow and take full width */
    display: flex;
    justify-content: center;
    /* Center horizontally */
    align-items: center;
    /* Center vertically */
    height: 60px;
    /* Increase height for better tap target */
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .flex-container {
        flex-direction: column;
    }

    /* Ensure numpad rows remain horizontal on smaller screens */
    #numpad div {
        flex-direction: row;
        /* Set row layout for numpad buttons */
        justify-content: space-between;
        /* Distribute space between buttons */
    }
}

@media (max-width: 480px) {

    .flex-container>div,
    .flex-container-column>div {
        font-size: 20px;
        padding: 15px;
    }

    #numpad div {
        font-size: 20px;
        padding: 10px;
    }

    #number-0 {
        height: 60px;
        /* Keep a consistent height for the number 0 button */
    }

    #channel-input input {
        height: 40px;
        font-size: 16px;
    }
}