/* Libron, the typeface of the documentation, copied from docs/docs/fonts by
   build.sh. It is licensed under the SIL Open Font License 1.1, see fonts/OFL.txt. */
@font-face {
  font-family: "Libron";
  src: url("fonts/Libron-Regular.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Libron";
  src: url("fonts/Libron-Italic.woff2") format("woff2");
  font-weight: 400;
  font-style: italic;
  font-display: swap;
}

@font-face {
  font-family: "Libron";
  src: url("fonts/Libron-Bold.woff2") format("woff2");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Libron";
  src: url("fonts/Libron-BoldItalic.woff2") format("woff2");
  font-weight: 700;
  font-style: italic;
  font-display: swap;
}

/* The colours of the documentation: the gold of the logo from
   docs/docs/stylesheets/brand.css, in the dark "slate" scheme of its theme and
   with the code colours of its highlighter. The renders and the run view stay
   dark; the rest of the start page follows the system scheme like the
   documentation does. */
:root,
.hero,
#run {
  --night: #0b0c0f;
  --deck: #14161f;
  --rule: #24262b;
  --fog: #bbbdc2;
  --heading: #ffffff;
  --slate: #83858a;
  --link: #e7ce70;
  --primary: #e5c65c;
  --primary-hover: color-mix(in srgb, #e5c65c 80%, #fff);
  --on-primary: #1f1d1a;
  --accent: #e5c65c;
  --hl-constant: #9383e2;
  --hl-string: #2fb170;
  --hl-number: #e6695b;
  --hl-function: #c973d9;
  --hl-keyword: #6791e0;
  --hl-special: #f06090;
  --hl-name: #c4cad8;
  color-scheme: dark;
  color: var(--fog);
}

/* The documentation's default scheme. */
@media (prefers-color-scheme: light) {
  :root {
    --night: #ffffff;
    --deck: #f5f5f5;
    --rule: #e3e3e3;
    --fog: #212121;
    --heading: #1a1a1a;
    --slate: #737373;
    --link: #806308;
    --accent: #806308;
    --hl-constant: #6e59d9;
    --hl-string: #1c7d4d;
    --hl-number: #d52a2a;
    --hl-function: #a846b9;
    --hl-keyword: #3f6ec6;
    --hl-special: #db1457;
    --hl-name: #36464e;
    color-scheme: light;
  }
}

:root {
  --text: "Libron", Georgia, "Times New Roman", serif;
  --mono: ui-monospace, "JetBrains Mono", "Fira Code", Menlo, Consolas, monospace;
  /* Outlined buttons keep their weight next to bold labels on dense screens. */
  --outline: 1px;
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background: var(--night);
  color: var(--fog);
  font-family: var(--text);
  font-size: 17px;
  line-height: 1.6;
}

a {
  color: var(--link);
  text-underline-offset: 0.15em;
}

code,
select,
textarea {
  font-family: var(--mono);
  font-size: 0.88em;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Start screen */

.hero {
  position: relative;
  height: min(58vh, 560px);
  min-height: 300px;
  overflow: hidden;
  border-bottom: 1px solid var(--rule);
}

/* Renders of the demos, cross-fading from one to the next. */
.hero-renders figure {
  position: absolute;
  inset: 0;
  margin: 0;
  opacity: 0;
  transition: opacity 1.6s ease;
}

.hero-renders figure.shown {
  opacity: 1;
}

.hero-renders img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: 55% 40%;
}

/* Names the recording shown, in the corner the title leaves free. */
.hero-renders figcaption {
  position: absolute;
  z-index: 1;
  right: 1.5rem;
  bottom: 1.75rem;
  color: var(--slate);
  font-size: 0.8rem;
}

@media (prefers-reduced-motion: reduce) {
  .hero-renders figure {
    transition: none;
  }
}

@media (max-width: 760px) {
  .hero-renders figcaption {
    top: 0.9rem;
    bottom: auto;
  }
}

/* Darkens the render where the title sits. */
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, var(--night) 4%, transparent 55%);
}

.hero-text {
  position: absolute;
  z-index: 1;
  left: 0;
  right: 0;
  bottom: 0;
  max-width: 68rem;
  margin: 0 auto;
  padding: 0 1.5rem 1.75rem;
}

/* Libron's own letterforms carry the title, so it keeps their spacing. */
h1,
h2 {
  color: var(--heading);
}

h1 {
  margin: 0;
  font-size: clamp(3rem, 9vw, 6.5rem);
  font-weight: 700;
  line-height: 0.95;
  letter-spacing: -0.01em;
}

.project-brand {
  display: flex;
  align-items: center;
  gap: 0.18em;
}

.project-brand img {
  width: 0.95em;
  height: 0.95em;
  flex: none;
}

.hero-text p {
  margin: 0.6rem 0 0;
  max-width: 40rem;
  font-size: 1.15rem;
}

/* The project's links, as on a paper's project page: one row of equal links. */
.project-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1.2rem;
}

.project-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.4rem 0.95rem 0.4rem 0.8rem;
  border: var(--outline) solid var(--link);
  border-radius: 999px;
  background: rgb(11 12 15 / 0.65);
  color: var(--link);
  font-weight: 700;
  font-size: 0.95rem;
  text-decoration: none;
}

.project-links svg {
  width: 1.15em;
  height: 1.15em;
  flex: none;
}

.project-links a:hover {
  background: color-mix(in srgb, var(--link) 12%, transparent);
}

.choices {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  max-width: 68rem;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 0;
}

.choice h2 {
  margin: 0 0 0.5rem;
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.choice p {
  margin: 0;
  max-width: 34rem;
  color: var(--slate);
}

.choice em,
.choice code {
  color: var(--fog);
}

.action {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  margin-top: 1.25rem;
}

/* The demo recordings, one row each with its own Run button. */
#demos {
  margin: 1.25rem 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--rule);
}

#demos li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--rule);
}

#demos strong {
  display: block;
  font-weight: 700;
}

/* The dataset a group of demos comes from. */
#demos .dataset {
  display: block;
  padding: 1.1rem 0 0.35rem;
  color: var(--slate);
  font-size: 0.85rem;
}

#demos .dataset:first-child {
  padding-top: 0.6rem;
}

#demos span {
  color: var(--slate);
  font-size: 0.9rem;
}

#demos .primary {
  min-width: 6.2rem;
  padding: 0.45rem 1.1rem;
  font-variant-numeric: tabular-nums;
}

/* A downloading demo fills its Run button from the left. */
#demos .primary.loading,
#demos .primary.loading:disabled {
  opacity: 1;
  background: linear-gradient(
    to right,
    var(--primary) var(--progress, 0%),
    var(--deck) var(--progress, 0%)
  );
  box-shadow: inset 0 0 0 var(--outline) var(--primary);
}

button {
  font: inherit;
  cursor: pointer;
  border-radius: 6px;
}

.primary {
  padding: 0.6rem 1.25rem;
  border: none;
  /* The pill shape of the documentation's buttons. */
  border-radius: 999px;
  background: var(--primary);
  color: var(--on-primary);
  font-weight: 700;
}

.primary:hover {
  background: var(--primary-hover);
}

button:disabled {
  opacity: 0.55;
  cursor: progress;
}

/* The file input is hidden behind a button-like label. */
.file input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
}

.file span {
  display: inline-block;
  padding: 0.55rem 1.15rem;
  border: var(--outline) solid var(--link);
  border-radius: 999px;
  color: var(--link);
  font-weight: 700;
  cursor: pointer;
}

.file span:hover {
  background: color-mix(in srgb, var(--link) 10%, transparent);
}

.file input:focus-visible + span {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

#own-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.9rem;
  margin-top: 1.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--rule);
}

#own-options label {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  color: var(--slate);
  font-size: 0.9rem;
}

#own-options .wide {
  grid-column: 1 / -1;
}

#own-options .action {
  margin-top: 0.25rem;
}

select,
textarea {
  width: 100%;
  padding: 0.45rem 0.55rem;
  border: 1px solid var(--rule);
  border-radius: 6px;
  background: var(--deck);
  color: var(--fog);
}

/* Progress and errors, right under the action that started them. */
.status {
  margin: 0.75rem 0 0;
  color: var(--accent);
  font-size: 0.92rem;
}

.status:empty {
  display: none;
}

/* The rule lines up with the content, not the page padding. */
footer {
  width: calc(100% - 3rem);
  max-width: 65rem;
  margin: 2rem auto 0;
  padding: 1.25rem 0 2.5rem;
  border-top: 1px solid var(--rule);
}

footer p {
  max-width: 44rem;
  margin: 0 0 0.8rem;
  color: var(--slate);
  font-size: 0.82rem;
}

@media (max-width: 760px) {
  .choices {
    grid-template-columns: 1fr;
    gap: 2.25rem;
  }

  #own-options {
    grid-template-columns: 1fr;
  }
}

/* Run view */

#run {
  position: fixed;
  inset: 0;
  display: grid;
  /* --split is the share of the first pane, set by dragging the divider. */
  grid-template-columns: minmax(0, var(--split, 40%)) 1px minmax(0, 1fr);
  grid-template-rows: minmax(0, 1fr);
  grid-template-areas: "tui divider cloud";
  background: var(--night);
}

#tui {
  grid-area: tui;
  position: relative;
  min-width: 0;
  min-height: 0;
  background: var(--night);
}

#tui canvas,
#cloud {
  display: block;
  width: 100%;
  height: 100%;
}

#cloud-pane {
  grid-area: cloud;
  position: relative;
  min-width: 0;
  min-height: 0;
}

#cloud {
  touch-action: none;
  cursor: grab;
}

#cloud:active {
  cursor: grabbing;
}

/* A one-pixel rule with a wider grab area over the neighbouring panes. */
#divider {
  grid-area: divider;
  position: relative;
  z-index: 2;
  background: var(--rule);
  cursor: col-resize;
  touch-action: none;
}

#divider::before {
  content: "";
  position: absolute;
  inset: 0 -5px;
}

#divider:hover,
#divider.dragging {
  background: var(--accent);
}

/* Explains the colours of the 3D view, and switches between them. */
#legend {
  position: absolute;
  top: 0.9rem;
  right: 0.9rem;
  width: 12.5rem;
  margin: 0;
  pointer-events: none;
}

/* The shader's colour map from low to high, filled in by main.js. */
#legend .ramp {
  height: 6px;
  border-radius: 3px;
}


#color-by {
  display: flex;
  justify-content: flex-end;
  margin-bottom: 0.45rem;
  pointer-events: auto;
}

#color-by button {
  padding: 0.15rem 0.55rem;
  border: 1px solid var(--rule);
  border-radius: 0;
  margin-left: -1px;
  background: rgb(20 23 31 / 0.88);
  color: var(--slate);
  font-size: 0.72rem;
}

#color-by button:first-child {
  border-radius: 5px 0 0 5px;
}

#color-by button:last-child {
  border-radius: 0 5px 5px 0;
}

#color-by button[aria-pressed="true"] {
  position: relative;
  border-color: var(--slate);
  color: var(--fog);
}

#legend figcaption {
  display: flex;
  justify-content: space-between;
  margin-top: 0.3rem;
  color: var(--slate);
  font-size: 0.72rem;
}

#controls {
  position: absolute;
  left: 0.9rem;
  right: 0.9rem;
  bottom: 0.9rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 0.75rem;
  pointer-events: none;
}

#controls button {
  pointer-events: auto;
  padding: 0.3rem 0.7rem;
  border: 1px solid var(--rule);
  background: rgb(20 23 31 / 0.88);
  color: var(--fog);
  font-size: 0.82rem;
  white-space: nowrap;
}

#controls button:hover {
  border-color: var(--slate);
}

/* The layout switch: three joined buttons, the active one in the primary colour. */
#layout {
  display: flex;
  pointer-events: auto;
}

#layout button {
  border-radius: 0;
  margin-left: -1px;
}

#layout button:first-child {
  margin-left: 0;
  border-radius: 6px 0 0 6px;
}

#layout button:last-child {
  border-radius: 0 6px 6px 0;
}

#layout button[aria-pressed="true"] {
  position: relative;
  border-color: var(--primary);
  background: var(--primary);
  color: var(--on-primary);
  font-weight: 700;
}

.hint {
  margin-left: auto;
  color: var(--slate);
  font-size: 0.75rem;
}

/* A device with a mouse also has a keyboard for the TUI. */
@media (hover: hover) and (pointer: fine) {
  .touch-only,
  .hint.touch {
    display: none !important;
  }
}

@media not ((hover: hover) and (pointer: fine)) {
  .hint.mouse {
    display: none;
  }
}

/* The TUI keeps its size under the 3D view, so its layout does not jump. */
#run.cloud-only #cloud-pane {
  grid-column: 1 / -1;
  grid-row: 1;
  z-index: 1;
}

#run.cloud-only #divider,
#run.tui-only #divider {
  display: none;
}

#run.tui-only {
  grid-template-columns: minmax(0, 1fr) 0 0;
}

/* Over the empty end of the TUI's header bar. The 3D pane has no size here,
   so the controls are placed against the window. */
#run.tui-only #controls {
  position: fixed;
  left: auto;
  right: 0.4rem;
  top: 0.15rem;
  bottom: auto;
}

#run.tui-only #controls button {
  padding: 0 0.55rem;
  font-size: 0.72rem;
}

#run.tui-only .hint,
#run.tui-only #legend,
#run.tui-only #follow {
  display: none !important;
}

/* With a mouse the keyboard drives the TUI, so only the layout switch stays. */
@media (hover: hover) and (pointer: fine) {
  #run.tui-only .touch-only {
    display: none;
  }
}

/* On touch screens the buttons stay along the bottom, over the TUI's help bar,
   which lists keys a phone does not have. */
@media not ((hover: hover) and (pointer: fine)) {
  #run.tui-only #controls {
    left: 0;
    right: 0;
    top: auto;
    bottom: 0;
    padding: 0.45rem 0.5rem;
    border-top: 1px solid var(--rule);
    background: var(--night);
  }

  #run.tui-only #controls button {
    padding: 0.4rem 0.55rem;
    font-size: 0.78rem;
  }
}

/* Portrait screens, phones in particular: the 3D view on top, the TUI below. */
@media (max-aspect-ratio: 1/1) {
  #run {
    grid-template-columns: minmax(0, 1fr);
    grid-template-rows: minmax(0, var(--split, 55%)) 1px minmax(0, 1fr);
    grid-template-areas:
      "cloud"
      "divider"
      "tui";
  }

  #divider {
    cursor: row-resize;
  }

  #divider::before {
    inset: -5px 0;
  }

  #run.cloud-only #cloud-pane {
    grid-column: 1;
    grid-row: 1 / -1;
  }

  #run.tui-only {
    grid-template-columns: minmax(0, 1fr);
    grid-template-rows: 0 0 minmax(0, 1fr);
  }
}

/* Fingers need a larger grab area and larger buttons. */
@media (pointer: coarse) {
  #divider::before {
    inset: 0 -12px;
  }

  #controls button {
    padding: 0.5rem 0.85rem;
  }
}

@media (pointer: coarse) and (max-aspect-ratio: 1/1) {
  #divider::before {
    inset: -12px 0;
  }
}

/* Narrow phones: one row of compact buttons, without the gesture hint. */
@media (max-width: 600px) {
  #controls {
    left: 0.5rem;
    right: 0.5rem;
    bottom: 0.5rem;
    gap: 0.35rem;
  }

  #controls button {
    padding: 0.4rem 0.55rem;
    font-size: 0.78rem;
  }

  .hint {
    display: none !important;
  }
}

/* Ratslang editor: a highlighted <pre> under a textarea with transparent text. */
.rl-editor {
  position: relative;
}

.rl-editor pre,
.rl-editor textarea {
  margin: 0;
  width: 100%;
  min-height: 14rem;
  padding: 0.6rem 0.7rem;
  border: 1px solid var(--rule);
  border-radius: 6px;
  font-family: var(--mono);
  font-size: 0.85rem;
  line-height: 1.5;
  tab-size: 2;
  white-space: pre;
  overflow: auto;
}

/* Follows the textarea's scroll position, so it needs no scrollbars of its own. */
.rl-editor pre {
  position: absolute;
  inset: 0;
  overflow: hidden;
  background: var(--deck);
  color: var(--fog);
  pointer-events: none;
}

.rl-editor textarea {
  position: relative;
  display: block;
  resize: vertical;
  background: transparent;
  color: transparent;
  caret-color: var(--fog);
  scrollbar-color: var(--rule) transparent;
}

.rl-editor textarea::placeholder {
  color: var(--slate);
}

.rl-editor textarea::selection {
  background: color-mix(in srgb, var(--accent) 30%, transparent);
}

.rl-comment {
  color: var(--slate);
  font-style: italic;
}

.rl-annotation {
  color: var(--hl-constant);
  font-style: normal;
}

.rl-string,
.rl-escape {
  color: var(--hl-string);
}

.rl-number,
.rl-quantity {
  color: var(--hl-number);
}

.rl-constant {
  color: var(--hl-constant);
}

.rl-internal {
  color: var(--hl-function);
  font-style: italic;
}

.rl-namespace {
  color: var(--hl-keyword);
}

.rl-value {
  color: var(--hl-special);
}

.rl-variable {
  color: var(--hl-name);
}

.rl-operator,
.rl-punctuation {
  color: var(--slate);
}

@media (min-resolution: 1.5dppx) {
  :root {
    --outline: 1.5px;
  }
}