index.css

html, body {
    height: 100%;
}

#content {
    padding: 0 15% 2em 15%;
}

#version {
    float: right;
    font-size: small;
    margin: 1em 1em 0 0;
}

h1 {
    clear: both;
}

.dev h1 {
    display: none;
}

.contact {
    text-decoration: none;
}

#warning {
    padding-top: 1em;
    font-size: x-large;
}

#dev-border.dev {
    border: .5em solid rgba(255, 255, 0, .5);
    border-image: repeating-linear-gradient(
        -45deg,
        rgba(0, 0, 0, .5) 0,
        rgba(0, 0, 0, .5) 15px,
        rgba(255, 255, 0, .5) 0,
        rgba(255, 255, 0, .5) 30px
    ) 15;
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    z-index: -1;
}

#spoilers-container {
    margin-top: 1.1ex;
    margin-left: 1em;
    overflow: hidden;
    font-family: monospace;
}

#spoilers {
    margin: 0;
    resize: none;
    width: 100%;
    height: 100%;
    margin-bottom: -.5em;
    border: none;
    white-space: pre;
}

h3 time {
    font-size: medium;
}

#target {
    height: 9em;
    display: flex;
    align-items: center;
    justify-content: center;
}

#target div {
    text-align: center;
}

fieldset .pure-g .pure-u-12-24,
fieldset .pure-g .pure-u-1 {
    margin: .1em 0;
}

fieldset .pure-g .pure-u-12-24 fieldset {
    margin-right: 1em;
}

form > fieldset,
form > .pure-u-14-24 > fieldset {
    margin-bottom: .5em;
}

fieldset {
    padding: .45em .5em;
}

#buttons {
    margin: 0 0 .5em 0;
}

#notification {
    margin: 10px;
    position: fixed;
    bottom: 0;
    right: 0;
    display: none;
}

#notification.success {
    display: block;
    opacity: 1;
}

#preset-select.hide {
    visibility: hidden;
}

#loader {
    height: 4px;
    width: 100%;
    position: relative;
    overflow: hidden;
    background-color: #ddd;
}

#loader.hide {
    visibility: hidden;
}

#loader:before{
    display: block;
    position: absolute;
    content: "";
    left: -200px;
    width: 200px;
    height: 4px;
    background-color: #2980b9;
    animation: loading 2s linear infinite;
}

@keyframes loading {
    from {left: -200px; width: 30%;}
    50% {width: 30%;}
    70% {width: 70%;}
    80% { left: 50%;}
    95% {left: 120%;}
    to {left: 100%;}
}

#fork {
    position: absolute;
    top: 0;
    left: 0;
}

.tooltip-indicator {
    font-size: small;
    font-weight: bold;
    border-radius: 50%;
    display: inline-block;
    width: 1em;
    height: 1em;
    text-align: center;
}

.tooltip-wrapper {
    cursor: help;
    position: relative;
}

.tooltip-wrapper .tooltip {
    margin-bottom: 1em;
    bottom: 100%;
    display: block;
    opacity: 0;
    pointer-events: none;
    position: absolute;
}

.tooltip-wrapper .tooltip:before {
    content: ' ';
    display: block;
    height: 20px;
    left: 0;
    position: absolute;
    width: 100%;
}

#preset-author {
    position: absolute;
    bottom: 3px;
    right: 5px;
    font-size: small;
    color: #999;
}

fieldset > div > div > label:first-child {
    margin-left: 2.6em;
}

fieldset > div > fieldset > div > div > label:first-child {
    margin-left: 1.8em;
}

fieldset > div > div > input {
    margin-left: 1.45em;
}

fieldset > div > fieldset > div > div > input {
    margin-left: .7em;
}

div > div + fieldset {
    margin-top: .5em;
}

#seed {
    width: 15ex;
}

select,
input[type="text"],
input[type="number"] {
    margin-left: 2em;
}

input[type="number"] {
    width: 2.5em;
}

/* Menu mode */

body.menu {
    background: linear-gradient(
        180deg,
        rgba(2,0,36,1) 0%,
        rgba(0,0,32,1) 11%,
        rgba(65,65,150,1) 100%
    ) fixed;
}

.menu {
    color: #fff;
    background: transparent;
}

.menu a:link {
    color: #9cf;
}

.menu a:visited {
    color: #c9f;
}

.menu .contact {
    filter: invert(1);
}

.menu select,
.menu input[type="text"],
.menu input[type="number"],
.menu #spoilers {
    color: #fff;
    background: transparent;
}

.menu select {
    background: rgb(32,32,75,1);
}

.menu input[type="submit"] {
    font-weight: bold;
    color: #fff;
    background: transparent;
    border: none;
    font-size: x-large;
    padding: 6px;
}

.menu input[type="submit"]:disabled {
    visibility: hidden;
}

.menu input[type="submit"]#randomize:enabled {
    animation: pulse 1s infinite;
}

.menu #target.animate {
    animation: expand-target 2s;
    overflow: hidden;
}

.menu #target-container > div {
    margin: 0 .3em .2em .3em;
}

.menu #target,
.menu #spoilers-container {
    border: 1px #fff solid;
}

.menu #target.error {
    animation: pulse 1s infinite;
}

.menu #target.animate.hide {
    animation: shrink-target 2s;
    animation-fill-mode: forwards;
}

.menu #target > div {
    width: 30em;
    white-space: nowrap;
}

@keyframes expand-target {
    0% {
        width: 0;
        height: 0;
    }
    100% {
        width: 100%;
        height: 9em;
    }
}

@keyframes shrink-target {
    0% {
        width: 100%;
        height: 9em;
    }
    99% {
        width: 0;
        height: 0;
    }
    100% {
        width: 0;
        height: 0;
        border-width: 0;
    }
}

@keyframes pulse {
    0% {
        background-color: #400000;
    }
    50% {
        background-color: #580000;
    }
    100% {
        background-color: #400000;
    }
}

.menu .tooltip-wrapper:hover .tooltip {
    width: 320px;
    opacity: 1;
    pointer-events: auto;
    animation: tooltip .5s;
    overflow: hidden;
}

.menu .tooltip-wrapper .tooltip > span {
    width: 280px;
    padding: 20px;
    display: block;
}

.menu #preset-author {
    position: absolute;
    display: block;
    width: 310px;
    right: auto;
    left: 0;
    text-align: right;
}

.menu fieldset {
    border: 1px #fff solid;
}

@keyframes tooltip {
    0% {
        width: 0;
        max-height: 0;
    }
    100% {
        width: 320px;
        max-height: 9.5em;
    }
}

.menu .tooltip-indicator {
    background: #fff;
    color: #999;
}

.menu .tooltip-wrapper .tooltip {
    background: linear-gradient(
        180deg,
        rgba(2,0,36,1) 0%,
        rgba(0,0,32,1) 11%,
        rgba(65,65,150,1) 100%
    ) fixed;
    border: 1px #fff solid;
}

.menu input[type="radio"]:disabled {
    opacity: .45;
}

.menu input[type="radio"]:checked:disabled {
    opacity: 1;
}

.menu #notification {
    animation: expand 2s;
    overflow: hidden;
    border: 1px #fff solid;
    background: linear-gradient(
        180deg,
        rgba(2,0,36,1) 0%,
        rgba(0,0,32,1) 11%,
        rgba(65,65,150,1) 100%
    ) fixed;
}

.menu #notification.hide {
    animation: shrink 2s;
}

.menu #notification span {
    display: inline-block;
    position: absolute;
    bottom: .3em;
    right: 1em;
    height: 1.25em;
    white-space: nowrap;
    text-align: center;
    width: 10em;
}

@keyframes expand {
    0% {
        width: 0;
        height: 0;
    }
    100% {
        width: 12em;
        height: 2em;
    }
}

@keyframes shrink {
    0% {
        width: 12em;
        height: 2em;
    }
    100% {
        width: 0;
        height: 0;
    }
}

.menu #spoilers-container.hide {
    animation: hide-spoilers 1s;
    animation-fill-mode: forwards;
}

.menu #spoilers-container {
    animation: show-spoilers 1s;
}

@keyframes show-spoilers {
    0% {
        max-width: 0;
        max-height: 0;
    }
    100% {
        max-width: 50ex;
        max-height: 11em;
    }
}

@keyframes hide-spoilers {
    0% {
        max-width: 50ex;
        max-height: 11em;
    }
    99.999% {
        max-width: 0;
        max-height: 0;
    }
    100% {
        max-width: 0;
        max-height: 0;
        border-width: 0;
    }
}

.menu #options > div {
    width: 47ex;
}

.menu #options.animate.hide {
    animation: hide-options 1s;
    animation-fill-mode: forwards;
}

.menu #options.animate {
    animation: show-options 1s;
}

@keyframes show-options {
    0% {
        max-width: 0;
        max-height: 0;
        margin-top: 0;
        padding: 0;
        overflow: hidden;
   }
    100% {
        max-width: 50ex;
        max-height: 15em;
        margin-top: .$em;
        padding: .45em .5em;
        overflow: hidden;
    }
}

@keyframes hide-options {
    0% {
        max-width: 50ex;
        max-height: 15em;
        margin-top: .5em;
        padding: .45em .5em;
        overflow: hidden;
    }
    99.999% {
        max-width: 0;
        max-height: 0;
        margin-top: 0;
        padding: 0;
        overflow: hidden;
    }
    100% {
        max-width: 0;
        max-height: 0;
        border-width: 0;
        margin-top: 0;
        padding: 0;
        overflow: hidden;
    }
}

/* Light mode */

.light {
    color: #000;
    background: #fff;
}

.light select,
.light input[type="text"],
.light input[type="number"],
.light #spoilers {
    color: #000;
    background: #fff;
}

.light input[type="text"],
.light select {
    border: 1px #aaa solid;
}

.light #notification {
    color: #000;
    background: #cfc;
    border-radius: .5em;
    padding: 1em;
}

.light #notification.success {
    transition: opacity 2s ease-in-out;
}

.light #notification.success.hide {
    opacity: 0;
}

.light .tooltip-indicator {
    background: #999;
    color: #fff;
}

.light .tooltip-wrapper .tooltip {
    width: 320px;
    padding: 1.25em;
    transform: translateY(10px);
    transition: all .25s ease-out;
    background: #fff;
    box-shadow: 2px 2px 6px rgba(0, 0, 0, 0.28);
}

.light .tooltip-wrapper:hover .tooltip {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0px);
}

.light #target {
    border-width: 10px;
    border-style: dashed;
    border-color: #ccc;
}

.light #target.active {
    border-color: #cfc;
}

.light #target.error {
    border-color: #fcc;
}

.light #target legend {
    display: none;
}

.light input[type="submit"] {
    color: #000;
    padding: .5em 1em;
    border-radius: 1px;
    border: none;
}

.light input[type="submit"]:disabled {
    opacity: .4;
}

.light input[type="submit"]:enabled:hover {
    background-image: linear-gradient(
        transparent,
        rgba(0,0,0,.05) 40%,
        rgba(0,0,0,.1)
    );
}

.light input[type="submit"].primary {
    color: #fff;
    background-color: #0078e7;
}

.light #spoilers-container {
    border: 1px silver solid;
}

.light #spoilers-container.hide {
    display: none;
}

.light #options.hide {
    display: none;
}

/* Dark mode */

.dark {
    color: #fff;
    background: #222;
}

.dark select,
.dark input[type="text"],
.dark input[type="number"],
.dark #spoilers {
    color: #fff;
    background: #222;
}

.dark input[type="text"],
.dark select {
    border: 1px #ccc solid;
}

.dark a:link {
    color: #69f;
}

.dark a:visited {
    color: #96f;
}

.dark .contact {
    filter: invert(1);
}

.dark #notification {
    color: #fff;
    background: #696;
    border-radius: .5em;
    padding: 1em;
}

.dark #notification.success {
    transition: opacity 2s ease-in-out;
}

.dark #notification.success.hide {
    opacity: 0;
}

.dark .tooltip-indicator {
    background: #fff;
    color: #999;
}

.dark .tooltip-wrapper .tooltip {
    width: 320px;
    padding: 1.25em;
    margin-bottom: 1em;
    transform: translateY(10px);
    transition: all .25s ease-out;
    background: #333;
    box-shadow: 2px 2px 6px rgba(0, 0, 0, .8);
}

.dark .tooltip-wrapper:hover .tooltip {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0px);
}

.dark #target {
    border-width: 10px;
    border-style: dashed;
    border-color: #ccc;
}

.dark #target.active {
    border-color: #cfc;
}

.dark #target.error {
    border-color: #fcc;
}

.dark #target legend {
    display: none;
}

.dark input[type="file"] {
    color: #fff;
    background: #222;
}

.dark input[type="radio"]:disabled {
    opacity: .45;
}

.dark input[type="radio"]:checked:disabled {
    opacity: 1;
}

.dark input[type="submit"] {
    color: #000;
    padding: .5em 1em;
    border-radius: 1px;
    border: none;
}

.dark input[type="submit"]:disabled {
    opacity: .4;
}

.dark input[type="submit"]:enabled:hover {
    background-image: linear-gradient(
        transparent,
        rgba(0,0,0,.05) 40%,
        rgba(0,0,0,.1)
    );
}

.dark input[type="submit"].primary {
    color: #fff;
    background-color: #0078e7;
}

.dark #spoilers-container {
    border: 1px silver solid;
}

.dark #spoilers-container.hide {
    display: none;
}

.dark #options.hide {
    display: none;
}