stylus/install-usercss/install-usercss.css

body {
  margin: 0;
  font: 12px arial, sans-serif;
  background: white;
}

a {
  color: #000;
  transition: color .5s;
  text-decoration-skip: ink;
}

a:hover {
  color: #666;
}

img.icon,
.svg-icon {
  height: 1.4em;
  vertical-align: middle;
}

.svg-icon {
  margin-left: 2px;
  fill: #000;
  transition: fill .5s;
}

a:hover .svg-icon {
  fill: #666;
}

input:disabled + span {
  color: rgb(128, 128, 128);
}

.container {
  display: flex;
  height: 100vh;
  align-items: stretch;
}

.main {
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.header,
.warnings {
  flex: 0 0 280px;
  box-sizing: border-box;
  padding: 15px;
  border-right: 1px dashed #aaa;
  box-shadow: 0 0 50px -18px black;
  overflow-wrap: break-word;
  overflow-y: auto;
  z-index: 100;
}

.header.meta-init-error {
  display: none;
}

.warnings {
  display: none;
  padding-bottom: 0;
  flex-basis: auto;
  background: #ffe2e2;
  border-right: none;
  border-bottom: 1px dashed #aaa;
}

.has-warnings .warnings {
  display: initial;
}

.warning {
  font-weight: bold;
  font-size: 125%;
  margin-bottom: 1em;
}

.warning pre {
  overflow-wrap: break-word;
  white-space: pre-wrap;
  margin: 1ex 0 0;
  font-weight: normal;
  font-size: 80%;
}

h1 {
  margin-top: 0;
}

h1 small {
  font-size: 0.6em;
}

.meta-version::before {
  content: " v";
}

.actions {
  margin-bottom: 1em;
}

.actions label {
  max-width: -moz-fit-content;
  max-width: fit-content;
  display: flex;
  align-items: center;
  margin: 0.5em 0;
}

.install {
  font-family: Arial, "DejaVu Sans", Verdana, Geneva, sans-serif;
  font-size: 14px;
  background: linear-gradient(#666, #555);
  color: white;
  border-radius: 4px;
  padding: 4px 38px 4px 10px;
  position: relative;
  display: inline-block;
  text-shadow: 1px 1px 1px #333;
  -webkit-appearance: none;
  -moz-appearance: none;
  border-style: none;
  margin-bottom: 1ex;
  cursor: pointer;
  box-shadow: inset 0 -1px 0 0 hsl(0, 0%, 24%), inset 0 1px 0 0 hsl(0, 0%, 30%), inset 1px 0 0 0 hsl(0, 0%, 24%);
}

.install:before,
.install:after {
  content: "";
  vertical-align: middle;
  box-sizing: border-box;
  border-radius: 0 4px 4px 0;
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  width: 30px;
}

.install:before {
  background-image: linear-gradient(hsl(176, 44%, 40%), hsl(176, 50%, 35%));
  box-shadow: inset 0 -1px 0 0 hsl(0, 0%, 24%), inset 0 1px 0 0 hsl(0, 0%, 30%), inset 1px 0 0 0 rgba(0, 0, 0, .3), inset -1px 0 0 0 hsl(0, 0%, 38%);
  padding: 5px 8px;
}

.install:after {
  background-image: url(../images/icon/16.png);
  background-repeat: no-repeat;
  background-position: center center;
}

.install:hover {
  filter: brightness(1.1);
  color: #eee;
  text-shadow: none;
}

.install.reinstall:after {
  background-color: #333;
  filter: grayscale(100%);
}

.install.update:before,
.install.update:after {
  filter: hue-rotate(-18deg) brightness(.7) contrast(2);
}

.install.installed,
h2.installed {
  display: none;
}

h2.installed.active {
  display: inline-block;
  font-weight: bold;
  margin-bottom: 1ex;
  margin-top: 0;
}

.actions label input {
  margin: 0 0.5em 0 0;
  flex: 0 0 auto;
}

.actions label span {
  min-width: 0;
}

.external {
  text-align: center;
}

.external > * {
  margin: 0 7.5px;
}

li {
  margin-left: -2em;
}

.main {
  overflow: hidden;
}

.main .CodeMirror {
  height: auto;
  border: none;
}

/* spinner-related */

.header {
  position: relative;
}

.header:not(.meta-init) > *:not(.lds-spinner),
.header.meta-init > .lds-spinner {
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
  pointer-events: none;
  opacity: 0;
}

.header.meta-init > * {
  opacity: 1;
  transition: opacity .5s;
  -webkit-user-select: auto;
  -moz-user-select: auto;
  -ms-user-select: auto;
  user-select: auto;
}

/* spinner: https://github.com/loadingio/css-spinner */

@keyframes lds-spinner {
  0% {
    opacity: 1;
  }
  100% {
    opacity: 0;
  }
}
@-webkit-keyframes lds-spinner {
  0% {
    opacity: 1;
  }
  100% {
    opacity: 0;
  }
}
.lds-spinner {
  position: absolute;
  width: 200px;
  height: 200px;
  top: 50px;
  left: 0;
  right: 0;
  margin: auto;
  opacity: .2;
  transition: opacity .5s;
}
.lds-spinner div {
  left: 94px;
  top: 23px;
  position: absolute;
  -webkit-animation: lds-spinner linear 1s infinite;
  animation: lds-spinner linear 1s infinite;
  background: currentColor;
  width: 12px;
  height: 34px;
  border-radius: 20%;
  -webkit-transform-origin: 6px 77px;
  transform-origin: 6px 77px;
}
.lds-spinner div:nth-child(1) {
  -webkit-transform: rotate(0deg);
  transform: rotate(0deg);
  -webkit-animation-delay: -0.916666666666667s;
  animation-delay: -0.916666666666667s;
}
.lds-spinner div:nth-child(2) {
  -webkit-transform: rotate(30deg);
  transform: rotate(30deg);
  -webkit-animation-delay: -0.833333333333333s;
  animation-delay: -0.833333333333333s;
}
.lds-spinner div:nth-child(3) {
  -webkit-transform: rotate(60deg);
  transform: rotate(60deg);
  -webkit-animation-delay: -0.75s;
  animation-delay: -0.75s;
}
.lds-spinner div:nth-child(4) {
  -webkit-transform: rotate(90deg);
  transform: rotate(90deg);
  -webkit-animation-delay: -0.666666666666667s;
  animation-delay: -0.666666666666667s;
}
.lds-spinner div:nth-child(5) {
  -webkit-transform: rotate(120deg);
  transform: rotate(120deg);
  -webkit-animation-delay: -0.583333333333333s;
  animation-delay: -0.583333333333333s;
}
.lds-spinner div:nth-child(6) {
  -webkit-transform: rotate(150deg);
  transform: rotate(150deg);
  -webkit-animation-delay: -0.5s;
  animation-delay: -0.5s;
}
.lds-spinner div:nth-child(7) {
  -webkit-transform: rotate(180deg);
  transform: rotate(180deg);
  -webkit-animation-delay: -0.416666666666667s;
  animation-delay: -0.416666666666667s;
}
.lds-spinner div:nth-child(8) {
  -webkit-transform: rotate(210deg);
  transform: rotate(210deg);
  -webkit-animation-delay: -0.333333333333333s;
  animation-delay: -0.333333333333333s;
}
.lds-spinner div:nth-child(9) {
  -webkit-transform: rotate(240deg);
  transform: rotate(240deg);
  -webkit-animation-delay: -0.25s;
  animation-delay: -0.25s;
}
.lds-spinner div:nth-child(10) {
  -webkit-transform: rotate(270deg);
  transform: rotate(270deg);
  -webkit-animation-delay: -0.166666666666667s;
  animation-delay: -0.166666666666667s;
}
.lds-spinner div:nth-child(11) {
  -webkit-transform: rotate(300deg);
  transform: rotate(300deg);
  -webkit-animation-delay: -0.083333333333333s;
  animation-delay: -0.083333333333333s;
}
.lds-spinner div:nth-child(12) {
  -webkit-transform: rotate(330deg);
  transform: rotate(330deg);
  -webkit-animation-delay: 0s;
  animation-delay: 0s;
}

/* https://github.com/lukehaas/css-loaders */
/*
.spinner {
  --color: currentColor;
  --background-color: currentColor;
  font-size: 10px;
  margin: 50px auto;
  text-indent: -9999em;
  width: 200px;
  height: 200px;
  border-radius: 50%;
  background: #ffffff;
  background: -moz-linear-gradient(left, #ffffff 10%, rgba(255, 255, 255, 0) 42%);
  background: -webkit-linear-gradient(left, #ffffff 10%, rgba(255, 255, 255, 0) 42%);
  background: -o-linear-gradient(left, #ffffff 10%, rgba(255, 255, 255, 0) 42%);
  background: -ms-linear-gradient(left, #ffffff 10%, rgba(255, 255, 255, 0) 42%);
  background: linear-gradient(to right, #ffffff 10%, rgba(255, 255, 255, 0) 42%);
  position: relative;
  -webkit-animation: load3 1.4s infinite linear;
  animation: load3 1.4s infinite linear;
  -webkit-transform: translateZ(0);
  -ms-transform: translateZ(0);
  transform: translateZ(0);
}

.spinner:before {
  width: 50%;
  height: 50%;
  background: #ffffff;
  border-radius: 100% 0 0 0;
  position: absolute;
  top: 0;
  left: 0;
  content: '';
}

.spinner:after {
  background: #0dc5c1;
  width: 75%;
  height: 75%;
  border-radius: 50%;
  content: '';
  margin: auto;
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
}
*/

@-webkit-keyframes load3 {
  0% {
    -webkit-transform: rotate(0deg);
    transform: rotate(0deg);
  }
  100% {
    -webkit-transform: rotate(360deg);
    transform: rotate(360deg);
  }
}
@keyframes load3 {
  0% {
    -webkit-transform: rotate(0deg);
    transform: rotate(0deg);
  }
  100% {
    -webkit-transform: rotate(360deg);
    transform: rotate(360deg);
  }
}

/************ reponsive layouts ************/

@media (max-width:10in) {
  .container {
    flex-direction: column;
  }
  .header {
    flex-basis: auto;
    border-right: none;
    border-bottom: 1px dashed #AAA;
    max-height: 50%;
    overflow-x: auto;
    overflow-y: hidden;
  }
  .has-warnings .header {
    min-height: 4em;
    max-height: 20%;
  }
  .warnings {
    max-height: 20%;
  }
  .warning:not(:last-child) {
    border-bottom: 1px dashed #b57c7c;
    padding-bottom: 1em;
  }
  .header,
  .warning {
    -webkit-column-count: 3;
    -moz-column-count: 3;
    column-count: 3;
  }
  h1 {
    -webkit-column-span: all;
    column-span: all;
    margin-bottom: .5em;
  }
  .actions {
    display: flex;
  }
  .install {
    margin-right: 1em;
  }
}

@media (max-width:7in) {
  .header,
  .warning {
    -webkit-column-count: 2;
    -moz-column-count: 2;
    column-count: 2;
  }
}

@media (max-width:4in) {
  .header {
    overflow-x: hidden;
    overflow-y: auto;
    max-height: 100%;
  }
  .header,
  .warning {
    -webkit-column-count: 1;
    -moz-column-count: 1;
    column-count: 1;
  }
  .warning {
    border: none;
    padding-bottom: unset;
  }
}

/* Retina-specific stuff here */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
  .install:after {
    background-image: url(../images/icon/32.png);
    background-size: 16px 16px;
  }
}