body {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 0;
    margin: 0;
    width: 100vw;
    height: 100vh;
    font-family: 'Rubik', sans-serif;
}

.container {
    display: flex;
    flex-direction: column;
    overflow: hidden;
    width: 72em;
    max-width: 100%;
    min-width: 34em;
    height: 50em;
    max-height: 100%;
    min-height: 46em;
    background-color: #ffffff;
    border-radius: 1em;
    border: 1px solid #e0e0e0;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
    font-size: 10px;
}

@media screen and (max-width: 480px) {
    .container {
        font-size: 5px;
    }
}

.container,
.container * {
    box-sizing: border-box;
}

.content {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
    margin: 2em 4em;
    font-size: 100%;
}

.button {
    color: #fff;
    border-radius: 1em;
    text-decoration: none;
    padding: 1em 2em;
    margin: 0.5em;
    text-align: center;
    font-size: 1.5em;
    transition: background-color 0.3s, transform 0.3s;
    cursor: pointer;
}

.button-happy {
    background-color: #6a4;
    border: none;
}

.button-happy:hover {
    background-color: #81c061;
}

.button-unhappy {
    background-color: #a43;
    border: none;
}

.button-unhappy:hover {
    background-color: #c85a48;
}

.face-slider {
    --happiness: 0.9;
    --derp: 1;
    --px: 0.5;
    --py: 0.5;
    width: 22em;
    max-width: 100%;
    height: 22em;
    background-image: radial-gradient(#f7e0b2, #eb5);
    border-radius: 100%;
    overflow: hidden;
    margin: 0 auto 2em auto;
    border: solid 2px #ecb23e;
    box-shadow: 0px 0px 5px rgba(0, 0, 0, 0.2);
    position: relative;
}

.face-slider,
.face-slider * {
    position: absolute;
}

.face-slider::before {
    content: '';
    display: block;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    background-image: linear-gradient(to bottom, #5a8, rgba(85, 170, 136, 0));
    opacity: calc(1 - var(--happiness));
}

.face-slider-blush {
    width: 20%;
    height: 10%;
    background-color: rgba(255, 100, 100, 0.3);
    border: 3px solid rgba(255, 100, 100, 0.3);
    top: calc(45% + var(--py) * 10%);
    border-radius: 100%;
    opacity: calc(var(--happiness) * var(--happiness) * 0.9 + 0.1);
}

.face-slider-blush-left {
    left: calc(7% + var(--px) * 2%);
}

.face-slider-blush-right {
    right: calc(9% - var(--px) * 2%);
}

.face-slider-eye {
    width: calc(26% - var(--happiness) * 2%);
    height: calc(26% - var(--happiness) * 2%);
    background-color: #f6f6f6;
    border-radius: 100%;
    top: calc(25% + var(--py) * 10%);
    overflow: hidden;
}

.face-slider-eye-left {
    left: calc(18% + var(--px) * 4%);
}

.face-slider-eye-left::after {
    transform: translate(calc((var(--px) + var(--derp) * 0.5) * 100%), calc((var(--py) + var(--derp) * 0.5) * 100%));
}

.face-slider-eye-right {
    right: calc(22% - var(--px) * 4%);
}

.face-slider-eye-right::after {
    transform: translate(calc((var(--px) + var(--derp) * -0.3) * 100%), calc((var(--py) + var(--derp) * -0.3) * 100%));
}

.face-slider-eye::after {
    content: '';
    display: block;
    background-color: #421;
    width: calc(55% - var(--happiness) * 10%);
    height: calc(55% - var(--happiness) * 10%);
    border-radius: 100%;
}

.face-slider-mouth {
    width: calc(51% - var(--happiness) * 2%);
    height: calc(26% - var(--happiness) * 2%);
    background-color: #a33;
    border-radius: calc((1 - var(--happiness)) * 10em) calc((1 - var(--happiness)) * 10em) calc(var(--happiness) * 16em) calc(var(--happiness) * 16em);
    top: calc(57.5% + var(--py) * 5%);
    left: calc(47.5% + var(--px) * 5%);
    transform: translateX(-50%);
    overflow: hidden;
    border: 3px solid #962d2d;
}

.face-slider-mouth::before {
    content: '';
    display: block;
    position: absolute;
    width: 20%;
    height: 20%;
    top: 0;
    left: 50%;
    background-color: white;
    border-radius: 0 0 0.5em 0.5em;
}

.face-slider-mouth::after {
    content: '';
    display: block;
    position: absolute;
    width: 60%;
    height: 50%;
    left: 10%;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.2);
    border-radius: 20em 20em 0 0;
}