html {
  --color: black;
  --background: white;
  --link-color: royalblue;

  font: normal 80% / 1.2 sans-serif;
  color: var(--color);
  background: var(--background);
  overscroll-behavior: contain;
}
html[data-mode="dark"],
html[data-mode="fantasy"] {
  --color: white;
  --background: #0d0c15;
  --link-color: deepskyblue;
}
html,
body {
  height: 100%;
  padding: 0;
  margin: 0;
}
body {
  display: flex;
  flex-direction: column;
}
a,
a:hover,
a:visited,
a:active {
  color: var(--link-color);
}
#screen {
  flex: auto;
  overflow: hidden;
  position: relative;
}
#screen svg {
  font: inherit;
  color: inherit;
  width: 100%;
  height: 100%;
}
#screen svg text {
  cursor: default;
  user-select: none;
}
#screen .stars {
  fill: currentColor;
  stroke: none;
  stroke-width: 0.75;
}
#screen .p {
  fill: none;
  stroke-linecap: round;
}
#screen .grid {
  stroke: currentColor;
  stroke-width: 0.55;
  stroke-opacity: 0.09;
  fill: none;
}
html[data-mode="light"] #screen .grid {
  stroke-opacity: 0.12;
}
#screen .star-labels {
  font-family: serif;
  fill: currentColor;
  fill-opacity: 0.5;
}
#screen .constellation-labels {
  font-size: 1em;
  font-weight: bold;
  font-style: italic;
  letter-spacing: 0.2em;
  text-anchor: middle;
  text-transform: uppercase;
  fill: currentColor;
  fill-opacity: 0.12;
}
#screen .hint-lines {
  stroke: currentColor;
  stroke-width: 0.5;
  stroke-dasharray: 3 2;
  stroke-opacity: 0.3;
  fill: none;
}
html[data-mode="light"] #screen .hint-lines {
  stroke-opacity: 0.5;
}
#screen .hidden {
  display: none;
}
#screen form {
  display: flex;
  padding: 0;
  margin: 0;
  position: absolute;
  inset: 1em auto auto 1em;
}
#screen form label {
  display: inline-block;
  position: relative;
  overflow: hidden;
  cursor: pointer;
}
#screen form label input {
  position: absolute;
  left: -10rem;
}
#screen form label span {
  display: inline-block;
  color: color(from var(--color) srgb r g b / 0.85);
  background: color(from var(--color) srgb r g b / 0.15);
  border: 0.05em solid color(from var(--color) srgb r g b / 0.3);
  padding: 0.35em 1.5em;
}
#screen form label input:checked + span {
  color: color(from var(--link-color) srgb r g b / 0.95);
  background: color(from var(--link-color) srgb r g b / 0.25);
}

footer {
  --link-color: color(from var(--color) srgb r g b / 0.8);

  font-weight: bold;
  border-radius: 0.5em 0 0 0;
  position: absolute;
  padding: 0.2em 0.65em 0.3em 0.75em;
  right: 0;
  bottom: 0;
}

#screenmenu {
  --x: 0px;
  --y: 0px;

  color: color(from var(--background) srgb r g b / 0.85);
  background: color(from var(--link-color) srgb r g b / 0.95);
  position: absolute;
  z-index: 100;
  left: var(--x);
  top: var(--y);
}
#screenmenu ul {
  display: inline-block;
  list-style: none;
  padding: 0;
  margin: 0;
}
#screenmenu table {
  border-collapse: collapse;
  border: none;
  margin: 0;
}
#screenmenu td {
  padding: 0.3em 0.5em 0.2em;
}
#screenmenu td:not(:first-child) {
  border-left: 0.05em solid color(from var(--background) srgb r g b / 0.25);
}
#screenmenu li,
#screenmenu td {
  white-space: nowrap;
  border-bottom: 0.05em solid color(from var(--background) srgb r g b / 0.85);
}
#screenmenu.wide li,
#screenmenu.wide td {
  white-space: normal;
}
#screenmenu button {
  display: block;
  width: 100%;
  color: inherit;
  background: transparent;
  border: none;
  cursor: pointer;
}
#screenmenu li,
#screenmenu button {
  padding: 0.3em 0.5em 0.2em;
  margin: 0;
  box-sizing: border-box;
}
#screenmenu .b {
  text-align: right;
}
#screenmenu .x {
  text-align: center;
  padding-left: 1em;
  padding-right: 1em;
}