breathing.css

html {
    position: fixed;
    height: 100%;
    width: 100%;
    text-align: center;
    background-color: #333;
    font-size: 21px;
    cursor: default;
    overflow: hidden;
}

body {
    position: fixed;
    margin: 0;
    height: 100%;
    width: 100%;
}

main {
    will-change: transform;
    transition: transform 0.5s;
    height: 100%;
    width: 100%;
}

#main-view {
    height: 100%;
    width: 100%;
}

#sidebar {
    position: absolute;
    background-color: #444;
    right: -15em;
    color: white;
    height: 100%;
    width: 15em;
    z-index: -1;
    overflow-x: hidden;
    overflow-y: scroll;
}

#sidebar div {
    position: fixed;
    width: 100%;
    height: 3em;
    background-color: #555;
}

#sidebar ul {
    list-style: none;
    text-align: right;
    height: 100%;
    padding: 0;
    margin: 0;
    font-family: 'Helvetica Neue', 'Segoe UI', Helvetica, Arial, sans-serif;
}

#sidebar li {
    padding: 1em 1em 0 0;
}

#sidebar li:first-child {
    padding-top: 5em;
}

#sidebar li:last-child {
    padding-bottom: 3em;
}

#sidebar li a {
    text-decoration: none;
    color: white;
    cursor: pointer;
}

#sidebar .checked:before {
    content: '';
    display: inline-block;
    width: 0.3em;
    height: 0.6em;
    border: solid #aaa;
    border-width: 0 3px 3px 0;
    transform: rotate(45deg);
    margin: 0 0.7em 0.1em;
}

#sidebar-toggle {
    color: white;
    position: fixed;
    outline: none;
    right: 0;
    margin: 0.5em;
    height: 2em;
    display: block;
    opacity: .33;
    transition: opacity .5s;
    z-index: 1;
}

#sidebar-toggle:hover,
#sidebar-toggle:focus-within,
#sidebar-toggle.open {
    opacity: 1;
}

#sidebar-toggle span {
    display: block;
    width: 1em;
    height: 3px;
    background-color: white;
    margin: 1em 0.5em;
}

#sidebar-toggle span::before {
    display: block;
    position: absolute;
    background-color: white;
    content: '';
    width: 1em;
    height: 3px;
    transform: translateY(-.33em);
}
  
#sidebar-toggle span::after {
    display: block;
    position: absolute;
    background-color: white;
    content: '';
    width: 1em;
    height: 3px;
    transform: translateY(.33em);
}

#sidebar-toggle.open span {
    background-color: transparent;
}

#sidebar-toggle.open span::before {
    transform: rotate(45deg);
}

#sidebar-toggle.open span::after {
    transform: rotate(-45deg);
}

#sidebar table {
    display: inline-block;
}

tr:last-child {
    height: 3em;
    vertical-align: bottom;
}

input {
    font-size: 21px;
    background-color: transparent;
    border: 1px solid #aaa;
    color: white;
    outline: none;
    padding: .33em;
}

input:focus {
    outline: 1px solid white;
}

input[type='text'] {
    width: 5em;
}

input[type='number'] {
    width: 2em;
}

input[type=number]::-webkit-inner-spin-button, 
input[type=number]::-webkit-outer-spin-button { 
  -webkit-appearance: none; 
  margin: 0; 
}

#circle circle {
    fill: skyblue;
}

#circle {
    display: inline-block;
    width: 50vh;
    height: 50vh;
    margin-top: 10vh;
    will-change: transform;
    transform: scale(0.25);
    -webkit-transition: all 4.0s ease-in-out;
    -moz-transition: all 4.0s ease-in-out;
    transition: all 4.0s ease-in-out;
}

#text {
    color: white;
    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
    margin-top: 10vh;
}


@media screen and (max-width: 600px) {

    #circle {
        width: 50vw;
        height: 50vw;
    }
}

@media screen and (orientation: portrait) {

    #circle {
        margin-top: 20vh;
        width: 50vw;
        height: 50vw;
    }
}

@media screen and (orientation: landscape) {

    #circle {
        width: 50vh;
        height: 50vh;
    }
}