style.css

@import url('https://fonts.googleapis.com/css2?family=Roboto&display=swap');

:root {
    --black-height: 190px;
    --black-width: 60px;
    --white-height: 320px;
    --white-width: 100px;
    --key-margin: -30px;
    --scale-desktop: 0.8;
    --scale-tablet: 0.6;
    --scale-mobile: 0.3;
    --bcg-color: #EEEFF1;
    --dark-color: #080808;
    --light-color: #cacaca;
    --main-color: #E74C3C;
    --secondary-color: #9b2b1e;
}

body {
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    background-color: var(--bcg-color);
    font-family: 'Roboto', sans-serif;
    color: var(--dark-color);
}

header {
    width: 100vw;
}

h1 {
    text-align: center;
    margin-top: 50px;
}

.title-span {
    position: relative;
}

.title-span::before {
    content: '';
    width: 100px;
    height: 8px;
    background-color: var(--main-color);
    position: absolute;
    top: 35px;
    left: -30px;
    z-index: -1;
    border-radius: 5px;
}

.board {
    width: 1400px;
    justify-content: center;
    margin: 10vh 0;
    display: flex;
}

form {
    display: flex;
    flex-direction: row;
    justify-content: space-around;
    width: 780px;
}

section {
    display: flex;
    flex-wrap: wrap;
    flex-direction: column;
}

.root-section {
    width: 15%;
}

.chord-section {
    width: 25%;
}

select {
    cursor: pointer;
    display: inline-block;
    position: relative;
    font-size: 16px;
    border: var(--light-color) solid 1px;
    border-radius: 5px;
    padding: 8px 6px;
    color: var(--dark-color);
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    background: url(./chevron-down-solid.svg) 96% / 15% no-repeat #F7F7F7;
    background-size: 12px;
}

label {
    border: var(--light-color) solid 1px;
    border-radius: 7px;
    padding: 8px 6px;
    background-color: #fff;
    text-align: center;
}

select.inactive {
    background-color: #EEEFF1;
    color: var(--light-color);
    border: var(--light-color) solid 1px;
}

label.inactive {
    background-color: #EEEFF1;
    color: var(--light-color);
    border: var(--light-color) solid 1px;
}

option {
    background-color: #fff;
    border: var(--light-color) solid 1px;
    color: var(--dark-color);
}

.chord-label,
.scale-label:hover {
    cursor: pointer;
}



.white {
    width: calc(var(--white-width)* 0.8);
    height: calc(var(--white-height)* 0.8);
    border: solid 1px var(--dark-color);
    background-color: #fff;
    border-radius: 0 0 6px 6px;
    margin-left: -4px;
    outline: none;
    cursor: pointer;
    position: relative;
}

.black {
    border-radius: 0 0 2px 2px;
    outline: none;
    cursor: pointer;
    z-index: 2;
    background-color: #222;
    width: calc(var(--black-width) * var(--scale-desktop));
    height: calc(var(--black-height) * var(--scale-desktop));
    margin-left: calc(var(--key-margin) * var(--scale-desktop));
    margin-right: calc(var(--key-margin) * var(--scale-desktop));
    position: relative;
}

.note {
    font-size: 1.8em;
    text-align: center;
    background-color: var(--main-color);
    border-radius: 50%;
    width: 45px;
    height: 45px;
    justify-content: center;
    align-items: center;
    display: flex;
    color: #fff;
    position: absolute;
    bottom: 1em;
    left: 15%;
    opacity: 0;
    pointer-events: none;
}

.note--root {
    background-color: var(--secondary-color);
}

button {
    cursor: pointer;
    font-size: 16px;
    border: var(--light-color) solid 1px;
    border-radius: 5px;
    color: #fff;
    background-color: var(--main-color);
    width: 150px;
    height: 37px;
    align-items: flex-end;
    letter-spacing: 1.5px;
}

button:hover {
    background-color: var(--secondary-color);
}

@media (max-width: 1200px) {
    form {
        justify-content: space-between;
        width: 700px;
    }
    .note {
        font-size: 1em ;
        text-align: center;
        width: 30px;
        height: 30px;
    }

    .white {
        width: calc(var(--white-width) * var(--scale-tablet));
        height: calc(var(--white-height) * var(--scale-tablet));
    }

    .black {
        width: calc(var(--black-width) * var(--scale-tablet));
        height: calc(var(--black-height) * var(--scale-tablet));
        margin-left: calc(var(--key-margin) * var(--scale-tablet));
        margin-right: calc(var(--key-margin) * var(--scale-tablet));
    }

    button {
        width: 130px;
        flex-shrink: 0;
    }
}

@media (max-width: 1024px) {
    form {
        width: 630px;
    }
    .note {
        font-size: 0.8em ;
        text-align: center;
        width: 20px;
        height: 20px;
    }

    .white {
        width: calc(var(--white-width) * var(--scale-mobile));
        height: calc(var(--white-height) * var(--scale-mobile));
    }

    .black {
        width: calc(var(--black-width) * var(--scale-mobile));
        height: calc(var(--black-height) * var(--scale-mobile));
        margin-left: calc(var(--key-margin) * var(--scale-mobile));
        margin-right: calc(var(--key-margin) * var(--scale-mobile));
    }
}

@media (max-width: 690px) {
    body{
        align-items: space-between;
        height: 100vh;
        overflow: hidden;
    }
    h1 {
        margin-top: 0rem;
        margin-bottom: 2rem;
        font-size: 1.5rem;
    }
    .board {
       transform: rotate(-90deg);
        -webkit-transform: rotate(-90deg);
        -moz-transform: rotate(-90deg);
        -o-transform: rotate(-90deg);
        -ms-transform: rotate(-90deg);
        transform: rotate(-90deg);
    }

    form {
        width: 90vw;
        flex-wrap: wrap;
        margin-top: 30px;
    }


    .root-section,
    .chord-section,
    .scale-section {
        align-items: center;
        margin-bottom: 5px;
    }

    label , .root-section,
    .chord-section,
    .scale-section {
        width: 26vw;
    }

    select {
        width: 28vw;
    }

    .note {
        transform: rotate(90deg);
        transform: rotate(90deg);
        -webkit-transform: rotate(90deg);
        -moz-transform: rotate(90deg);
        -o-transform: rotate(90deg);
        -ms-transform: rotate(90deg);
        transform: rotate(90deg);
    }

    button {
        width: 40vw;
        margin: 0 auto;
    }
}