style.css

* {
    border: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: monospace;
    user-select: none;

}

html, body {
    min-height: 100% !important;
    height: 100%;
}

body {
    width: 98vw;
    height: 95vh;
    background-color: #000;
    display: flex;
    flex-direction: column;
    /* align-items: center;
    justify-content: flex-start; */
    overflow: hidden;
}

#root {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translateX(-50%) translateY(-50%);
    background-color: #339;
    width: 100%;
    height: 100%;
background-color: #111;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-between;
}

@media (width > 1000px){
    #root {
        max-width: 900px;
    }
}

.button-window {
    width: 95%;
    height: 45%;
    background-color: #222;
    display: flex;
    align-items: center;
    justify-content: space-around;
}

.left-buttons, .right-buttons {
width: 47.5%;
height: 95%;
background-color: #333;
display: flex;
flex-direction: column;
justify-content: space-around;
align-items: center;
}

h1, p {
margin: 5px;
color: white;
}

span {
    color: white;
}

p {
    font-size: 16px;

}

.bd {
    width: 100%;
    height: 60px;
    display: flex;
    justify-content: space-around;
}

.display-div {
    background-color: #222;
    width: 75%;
    height: fit-content;
    margin-bottom: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.timer-button {
    width: 150px;
    height: 150px;
    border: none;
    color: white;
    background-color: #111;
    font-size: 3em;
}

.input-div {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.selected-value-div {
    /* background-color: #f005; */
    width: 95%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    text-align: center;
}

.selected-value-div p {
    
}

.adjustment-buttons {
    width: 60px;
    height: 60px;
    border: none;
    background-color: #444;
    color: white;
    font-size: 40px;
}

#min-interval-value, #max-interval-value, #min-bpm-value, #max-bpm-value, #min-rest-value, #max-rest-value {
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: white;
    color: black;
    font-size: 28px;
    font-family:system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    font-weight: 900;
}

.rest-buttons {
    height: 40%;
    width: 50%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-around;
    background-color: #333;

}

.start-stop {
    height: 10%;
    width: 95%;
    display: flex;
    justify-content: space-between;
}

.start-stop-buttons {
    width: 40%;
    height: 60px;
    color: white;
    font-size: 32px;
    font-weight: 900;
    letter-spacing: 3px;
    border: none;
}

#start-button {
    background-color: #0c0b;
}

#stop-button {
    background-color: #c00b;
}

.fade {
    opacity: .5;
    pointer-events: none;
}

.track {
    position: relative;
    width: 70px;
    height: 30px;
    background-color: #222;
    border-radius: 15px;
    display: flex;
    align-items: center;
    cursor: pointer;
}

.track::after {
    content: '';
    position: absolute;
    width: 90%;
    height: 90%;
    top: 50%;
    left: 50%;
    transform: translateX(-50%) translateY(-50%);
    border: 5px solid #666;
    border-radius: 50px;
    z-index: 5;
    /* background-color: white; */

}

.track-on {
    background-color: #888;
}

.slider {
    /* margin: 0 2px; */
    height: 98%;
    aspect-ratio: 1/1;
    border-radius: 15px;
    background-color: #444;
    transform: translateX(0);
    transition: 200ms ease;
    z-index: 4;
}

.slid {
    transform: translateX(40px);
    transition: 200ms ease;
}

.on-off {
    position: absolute;
}

.switch-on {
    left: 10px;
}

.switch-off {
    right: 6px;
}

.track-div {
    /* margin: 0;
    padding: 0;
    box-sizing: border-box; */
    display: flex;
    align-items: center;
}

#interval-lock {
    height: 40px;
    width: 40px;
    margin-left: 30px;
    font-size: 24px;
    cursor: pointer;
    border: none;
    border-radius: 50px;
}

#interval-lock:hover {
    transform: scale(.95);
}

#interval-lock:active {
    transform: scale(.9);
}

.black-back {
    background-color: #000;
}

.red-back {
border: 4px solid #f00;}

.yellow-back {
border: 4px solid #ff0;
}

.green-back {
border: 4px solid #0f0;
}

.randomize-toggle {
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%) translateY(-50%);
    font-size: 16px;
    color: white;
}

.help {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: 100%;
    background-color: #000;
    color: white;
    z-index: 99;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    transition: 500ms ease;

}

section li {
    font-size: 16px;
}

section h2 {
text-align: center;
}

@media (orientation: landscape){
    section {
        width: 50%;
    }

}

@media (orientation: portrait){
    section {
        width: 90%;
    }
}

.ok {
    height: 60px;
    width: 120px;
    font-size: 30px;
    border: none;
    border-radius: 5px;
}

.ok:hover {
    transform: scale(.95);
}

.ok:active {
    transform: scale(.9);
}

.help-up {
    transform: translateY(-120%);
    transition: 500ms ease;
}

.get-help {
    height: 60px;
    width: 60px;
    font-size: 24px;
    border: none;
    border-radius: 5px;
    background-color: #ddd;
}

.get-help:hover {
    transform: scale(.95);
}

.get-help:active {
    transform: scale(.9);
}