* {
    box-sizing: border-box;
}

body {

    margin: 0;

    font-family: Arial, Helvetica, sans-serif;

    background: #111;

    color: white;

    display: flex;

    justify-content: center;

    align-items: center;

    min-height: 100vh;

    padding: 20px;
}

.container {

    width: 100%;

    max-width: 420px;

    background: #222;

    border-radius: 16px;

    padding: 24px;

    box-shadow: 0 0 20px rgba(0,0,0,0.5);

}

h1 {

    text-align: center;

    margin-top: 0;

}

.control {

    margin-bottom: 24px;

}

label {

    display: block;

    text-align: center;

    margin-bottom: 8px;

    font-weight: bold;

}

input[type=number],
input[type=text] {

    text-align: center;

    width: 100%;

    font-size: 16px;

    padding: 10px;

}

.dual-control-row {
    display: flex;
    gap: 16px;
}

.dual-control {
    flex: 1;
}

.dual-control input {
    width: 100%;
}

.transpose-controls {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    align-items: center;
}

.transpose-controls button {
    width: 100%;
    padding: 8px 4px;
    border: none;
    border-radius: 8px;
    background: #4fd2ff;
    color: #111;
    font-weight: bold;
    font-size: 9px;
}

.transpose-controls button.active {
    background: #a2211d;
    color: white;
}

.transpose-controls input {
    width: 100%;
}



input[type=range] {

    width: 100%;

}

.output {

    text-align: center;

    font-size: 22px;

    margin-bottom: 24px;

}

.output span {

    display: block;

    margin-top: 10px;

    font-size: 34px;

    font-weight: bold;

    color: #4fd2ff;

}

.buttons {

    display: flex;

    gap: 16px;

}

button {

    flex: 1;

    font-size: 20px;

    padding: 8px;

    cursor: pointer;

     user-select: none;
    -webkit-user-select: none;
    -webkit-touch-callout: none;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;

}

.spinner {
    display: flex;
    align-items: center;
    gap: 10px;
}

.spinner input {
    flex: 1;
    text-align: center;
}

.spinner button {
    width: 50px;
    height: 42px;
    flex-shrink: 0;
   
}

/* Chrome, Edge, Safari */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

/* Firefox */
input[type="number"] {
    -moz-appearance: textfield;
    appearance: textfield;
}