/* anycube: the application. One stylesheet, no dependencies, system
   fonts. Dark by default, light where the system asks for it.

   The application is exactly one viewport tall, on a laptop and on a
   phone, and everything in it has one place and one size: the cube and its
   playback on one side; the input, the solution and Solve on the other.
   Nothing moves when a solution arrives, the mode changes or the size
   does. A page that hosts it adds its own stylesheet for whatever it puts
   around it. */

:root {
  color-scheme: dark;
  --bg: #0e1014;
  --bg-2: #14171d;
  --panel: #171a21;
  --line: #262b36;
  --line-2: #343a48;
  --ink: #ecebe6;
  --ink-2: #b4b8c4;
  --ink-3: #8a8fa0;
  --accent: #f7d038;
  --accent-ink: #15130a;
  --danger: #ff7a70;
  --danger-bg: #2a1614;
  --ok: #5fd08e;
  --stage-a: #232936;
  --stage-b: #0f1217;
  --cube-body: #0b0c0f;
  --cube-inside: #1b1e25;
  --cube-blank: #3a3f4b;
  --u: #f4f4ef;
  --r: #d92b3a;
  --f: #1faa59;
  --d: #f7d038;
  --l: #f58220;
  --b: #2f6fde;
  --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", "Cascadia Code", "JetBrains Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --radius: 14px;
  --gutter: 16px;
}

@media (prefers-color-scheme: light) {
  :root {
    color-scheme: light;
    --bg: #f4f1ea;
    --bg-2: #ece8de;
    --panel: #fffdf8;
    --line: #dcd7ca;
    --line-2: #c4beae;
    --ink: #17191d;
    --ink-2: #4a4e58;
    --ink-3: #6c707b;
    --accent: #17191d;
    --accent-ink: #fffdf8;
    --danger: #b3261e;
    --danger-bg: #fbe9e6;
    --ok: #1c7a44;
    --stage-a: #ffffff;
    --stage-b: #e4dfd2;
    --cube-body: #15171b;
    --cube-inside: #2a2d35;
    --cube-blank: #b9b5aa;
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 15px/1.5 var(--sans);
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

button,
input,
textarea {
  font: inherit;
  color: inherit;
}

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

.sr {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

[hidden] {
  display: none !important;
}

kbd {
  font: 0.85em var(--mono);
  padding: 1px 5px;
  border: 1px solid var(--line-2);
  border-radius: 5px;
}

/* ------------------------------------------------- the one-viewport app */

.app {
  height: 100vh;
  height: 100dvh;
  min-height: 480px;
  display: grid;
  grid-template-rows: auto auto minmax(0, 1fr);
}

/* The six colours, across the top. */
.stripe {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  height: 4px;
}
.stripe i:nth-child(1) { background: var(--u); }
.stripe i:nth-child(2) { background: var(--d); }
.stripe i:nth-child(3) { background: var(--l); }
.stripe i:nth-child(4) { background: var(--r); }
.stripe i:nth-child(5) { background: var(--f); }
.stripe i:nth-child(6) { background: var(--b); }

.top,
.bench {
  width: min(1320px, 100% - 2 * var(--gutter));
  margin-inline: auto;
}

.top {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 8px 0;
  min-height: 44px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  text-decoration: none;
  font: 600 1rem/1 var(--mono);
  letter-spacing: -0.01em;
  flex: none;
}
.brand b {
  font-weight: 600;
  color: var(--ink-3);
}

/* What the hosting page puts in the bar. */
.top-extra {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 18px;
  min-width: 0;
}

.bench {
  min-height: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(340px, 410px);
  gap: 16px;
  padding-bottom: 12px;
}

/* The cube, its playback, the solution. */
.stage-col {
  min-height: 0;
  min-width: 0;
  display: grid;
  /* One column no wider than its place, whatever is in it: the playback
     below the cube then fits itself to that width (see .transport). */
  grid-template-columns: minmax(0, 1fr);
  grid-template-rows: minmax(0, 1fr) auto;
  gap: 8px;
  container-type: inline-size;
}

/* Wherever the cube is drawn: as large a square as fits. */
.cube-host {
  container-type: size;
  display: grid;
  place-items: center;
}
.cube-host canvas {
  display: block;
  width: min(100cqw, 100cqh);
  aspect-ratio: 1;
  touch-action: none;
  cursor: grab;
}
.cube-host canvas:active {
  cursor: grabbing;
}

.stage {
  position: relative;
  min-height: 120px;
  border-radius: calc(var(--radius) + 4px);
  border: 1px solid var(--line);
  background: radial-gradient(120% 90% at 50% 28%, var(--stage-a), var(--stage-b) 72%);
  overflow: hidden;
}
.stage-size,
.stage-tools,
.next,
.status {
  position: absolute;
  margin: 0;
  z-index: 3;
}
.stage-size {
  top: 10px;
  left: 12px;
  font: 600 0.8rem/1 var(--mono);
  color: var(--ink-2);
  padding: 6px 9px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: color-mix(in srgb, var(--panel) 78%, transparent);
  pointer-events: none;
}
.stage-tools {
  top: 8px;
  right: 8px;
  display: flex;
  gap: 6px;
}
.tool {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  height: 30px;
  padding: 0 9px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: color-mix(in srgb, var(--panel) 78%, transparent);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--ink-3);
  cursor: pointer;
}
.tool svg {
  width: 15px;
  height: 15px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2.2;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.tool:hover {
  color: var(--ink);
}
.tool[aria-pressed="true"] {
  color: var(--ink);
  border-color: var(--ink-3);
  background: var(--panel);
}
/* The move that comes next, in letters, beside its arrows. */
.next {
  left: 12px;
  top: 46px;
  display: flex;
  align-items: baseline;
  gap: 7px;
  pointer-events: none;
}
.next span {
  font: 600 0.66rem/1 var(--sans);
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.next b {
  font: 700 clamp(1.5rem, 7cqmin, 2.6rem) / 1 var(--mono);
  letter-spacing: -0.03em;
}

/* Where a solve stands, and what is wrong with a cube: over the foot of the stage. */
.status {
  left: 50%;
  bottom: 10px;
  transform: translateX(-50%);
  width: max-content;
  max-width: calc(100% - 20px);
  padding: 8px 12px;
  border: 1px solid var(--line-2);
  border-radius: 12px;
  background: color-mix(in srgb, var(--panel) 94%, transparent);
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.18);
  font-size: 0.88rem;
  line-height: 1.35;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 2px 10px;
  align-items: center;
}
.status .text {
  margin: 0;
}
.status .text b {
  font-weight: 650;
}
.status .more-line {
  grid-column: 2;
  margin: 0;
  font-size: 0.8rem;
  color: var(--ink-3);
}
.status small {
  display: block;
  margin-top: 3px;
  opacity: 0.85;
  font: 0.82em/1.35 var(--mono);
}
.status.bad {
  border-color: color-mix(in srgb, var(--danger) 55%, var(--line));
  background: var(--danger-bg);
  color: var(--danger);
}
.status.bad .more-line {
  color: inherit;
  opacity: 0.85;
}
.status.good .mark {
  color: var(--ok);
}
.mark {
  width: 20px;
  height: 20px;
  display: grid;
  place-items: center;
  font-weight: 700;
}
/* Four stickers taking turns: the page is busy. */
span.busy {
  width: 20px;
  height: 20px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2px;
}
span.busy i {
  border-radius: 2.5px;
  animation: pulse 1.2s infinite ease-in-out;
}
span.busy i:nth-child(1) { background: var(--d); }
span.busy i:nth-child(2) { background: var(--r); animation-delay: 0.15s; }
span.busy i:nth-child(4) { background: var(--b); animation-delay: 0.3s; }
span.busy i:nth-child(3) { background: var(--f); animation-delay: 0.45s; }
@keyframes pulse {
  0%, 100% { opacity: 0.25; }
  40% { opacity: 1; }
}
.line {
  grid-column: 1 / -1;
  display: flex;
  gap: 4px;
  margin-top: 5px;
}
.line i {
  flex: 1;
  max-width: 34px;
  height: 5px;
  border-radius: 3px;
  background: var(--line-2);
}
.line i.ahead {
  background: var(--ink-3);
}
.line i.you {
  background: var(--accent);
}

/* The camera's picture takes the stage; the cube steps aside into a corner. */
.cam-frame {
  position: absolute;
  inset: 0;
  margin: auto;
  width: min(100cqw, 100cqh);
  aspect-ratio: 1;
  overflow: hidden;
  background: #000;
  z-index: 1;
}
.cam-frame video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.cam-frame.mirrored video,
.cam-frame.mirrored .cam-grid {
  transform: scaleX(-1);
}
.cam-grid {
  position: absolute;
  inset: 15%;
  display: grid;
  grid-template-columns: repeat(var(--n), 1fr);
  border: 2px solid rgba(255, 255, 255, 0.95);
  border-radius: 8px;
  box-shadow: 0 0 0 100vmax rgba(0, 0, 0, 0.42);
}
.cam-grid i {
  border: 1px solid rgba(255, 255, 255, 0.55);
  display: grid;
  place-items: center;
  color: transparent;
}
/* What is found in the picture, drawn over it: it turns with the picture when that is mirrored. */
.cam-found {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}
.cam-frame.mirrored .cam-found {
  transform: scaleX(-1);
}
.cam-grid[hidden] {
  display: none;
}
.cam-note {
  position: absolute;
  left: 50%;
  bottom: 10px;
  transform: translateX(-50%);
  margin: 0;
  padding: 5px 11px;
  border-radius: 999px;
  background: rgba(0, 0, 0, 0.62);
  color: #fff;
  font-size: 0.8rem;
  line-height: 1.2;
  white-space: nowrap;
  max-width: calc(100% - 16px);
  overflow: hidden;
  text-overflow: ellipsis;
}
.cam-frame.found .cam-note::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 8px;
  margin-right: 7px;
  border-radius: 50%;
  background: var(--ok);
}
/* What is being read from each cell: a mark in its middle, in the page's
   own colour for it, the sticker itself showing round it. Where the reading
   could as well be another colour the mark is a ring. */
.cam-grid i::after {
  content: "";
  width: 36%;
  aspect-ratio: 1;
  border-radius: 28%;
  background: currentColor;
  box-shadow: 0 0 0 2px rgba(255, 255, 255, 0.95), 0 0 0 3.5px rgba(0, 0, 0, 0.6);
}
.cam-grid i.unsure::after {
  background: none;
  border: 4px dashed currentColor;
  box-sizing: border-box;
}
.stage.scanning .stage-tools,
.stage.scanning .next {
  display: none;
}

/* Playback. */
.transport {
  display: grid;
  grid-template-columns: auto auto minmax(60px, 1fr) auto;
  grid-template-areas: "keys counter scrub speed";
  align-items: center;
  gap: 4px 12px;
}
/* Where the cube's column is narrow (a small window, a tablet upright, a
   phone) the slider goes on a row of its own, and narrower still the least
   used buttons go. By the column's width, not the window's: beside the
   panel the column can be narrow in a wide window. */
@container (max-width: 640px) {
  .transport {
    grid-template-columns: auto auto minmax(0, 1fr);
    grid-template-areas: "keys counter speed" "scrub scrub scrub";
    gap: 0 8px;
  }
  .speed {
    justify-self: end;
  }
}
@container (max-width: 480px) {
  .speed button {
    padding: 4px 6px;
  }
  .speed button[data-speed="0.5"],
  .speed button[data-speed="12"],
  #to-start,
  #to-end {
    display: none;
  }
}
.keys {
  grid-area: keys;
  display: flex;
  align-items: center;
  gap: 2px;
}
.key {
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  border: 1px solid transparent;
  border-radius: 50%;
  background: none;
  cursor: pointer;
}
.key svg {
  width: 19px;
  height: 19px;
  fill: currentColor;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.key:hover:not(:disabled) {
  background: var(--bg-2);
  border-color: var(--line);
}
.key:disabled {
  opacity: 0.35;
  cursor: default;
}
.key.play {
  width: 46px;
  height: 46px;
  margin-inline: 3px;
  background: var(--accent);
  color: var(--accent-ink);
}
.key.play:hover:not(:disabled) {
  background: var(--accent);
  filter: brightness(1.08);
}
.key.play svg {
  width: 22px;
  height: 22px;
  stroke-width: 0;
}
.key.play .icon-pause,
.key.play.playing .icon-play {
  display: none;
}
.key.play.playing .icon-pause {
  display: block;
}
.counter {
  grid-area: counter;
  margin: 0;
  font: 600 1.3rem/1 var(--mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
  white-space: nowrap;
}
.counter .of {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--ink-3);
  letter-spacing: 0;
}
#scrub {
  grid-area: scrub;
  width: 100%;
  margin: 0;
  accent-color: var(--accent);
  height: 20px;
}
.speed {
  grid-area: speed;
  display: inline-flex;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 2px;
  background: var(--bg-2);
}
.speed button {
  border: 0;
  background: none;
  border-radius: 999px;
  padding: 4px 8px;
  font: 500 0.78rem/1.2 var(--mono);
  color: var(--ink-3);
  cursor: pointer;
}
.speed button[aria-checked="true"] {
  background: var(--panel);
  color: var(--ink);
  box-shadow: 0 0 0 1px var(--line-2);
}

/* The lower part of the panel: the solution, or the cube the camera is reading. */
.lower {
  flex: 1;
  min-height: 0;
  display: flex;
}
.solution {
  flex: 1;
  min-width: 0;
  min-height: 0;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--bg);
  padding: 8px 10px 10px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  grid-template-rows: 28px minmax(0, 1fr);
  align-items: center;
  gap: 4px 10px;
}
.summary {
  margin: 0;
  color: var(--ink-3);
  font: 600 0.72rem/1 var(--sans);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.summary b {
  color: var(--ink);
  font: 650 0.9rem/1 var(--sans);
  letter-spacing: 0;
  text-transform: none;
  margin-right: 4px;
}
.moves,
.placeholder {
  grid-column: 1 / -1;
  grid-row: 2;
  align-self: stretch;
  min-height: 0;
}
.moves {
  overflow: auto;
  overscroll-behavior: contain;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  align-content: flex-start;
  gap: 4px 4px;
  position: relative;
}
.moves:empty {
  display: none;
}
.placeholder {
  margin: 0;
  font-size: 0.84rem;
  line-height: 1.4;
  color: var(--ink-3);
}
/* While a solve waits or runs, its state stands where the solution will be. */
.wait {
  grid-column: 1 / -1;
  grid-row: 2;
  align-self: stretch;
  min-height: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  text-align: center;
  padding: 0 8px;
}
.wait[hidden] {
  display: none;
}
.wait-title {
  margin: 0;
  font-size: 1.35rem;
  line-height: 1.2;
  font-weight: 500;
}
.wait-title b {
  font-weight: 750;
}
.wait-title span {
  font-variant-numeric: tabular-nums;
}
.wait-more {
  margin: 0;
  font-size: 0.84rem;
  line-height: 1.4;
  color: var(--ink-3);
}
.wait .line {
  width: min(100%, 260px);
  justify-content: center;
  margin: 0;
}
.wait .line i {
  height: 8px;
  border-radius: 4px;
}
.solution.waiting .moves,
.solution.waiting .placeholder,
.solution.waiting #copy {
  display: none;
}
.scan-slot {
  flex: 1;
  min-width: 0;
  display: none;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: radial-gradient(120% 90% at 50% 28%, var(--stage-a), var(--stage-b) 72%);
}
.lower.scanning .solution {
  display: none;
}
.lower.scanning .scan-slot {
  display: grid;
}
.scan-slot-narrow {
  display: none;
}

.part {
  display: contents;
}
/* Each phase begins a row of its own, under its title. */
.part h4 {
  flex: 0 0 100%;
  margin: 7px 0 1px;
  font: 600 0.66rem/1 var(--sans);
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--ink-3);
  white-space: nowrap;
}
.part:first-child h4 {
  margin-top: 0;
}
.part h4 span {
  font-family: var(--mono);
  letter-spacing: 0;
  margin-left: 4px;
}
.part ol {
  display: contents;
}
.part li {
  list-style: none;
}
.move {
  min-width: 2.2em;
  padding: 4px 6px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: none;
  font: 500 0.88rem/1.1 var(--mono);
  text-align: center;
  white-space: nowrap;
  cursor: pointer;
  color: var(--ink);
}
.move:hover {
  border-color: var(--line-2);
  background: var(--bg-2);
}
.move.done {
  color: var(--ink-3);
  border-color: transparent;
  background: var(--bg-2);
}
.move.now {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
}

/* Controls. */
.panel {
  position: relative;
  min-height: 0;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 4px);
  background: var(--panel);
  padding: 12px;
}
/* The input keeps one height whatever tab is open, so what is under it stays where it is. */
/* Nothing in it scrolls: each tab's contents are made to fit (the box of a
   long scramble scrolls its own text). */
.panels {
  flex: none;
  height: 196px;
  overflow: hidden;
}
.note {
  margin: 8px 0 0;
  font-size: 0.82rem;
  line-height: 1.4;
  color: var(--ink-3);
}
.note code {
  font: 0.92em var(--mono);
  color: var(--ink-2);
}
.tabpanel > .note:first-child {
  margin-top: 0;
  margin-bottom: 10px;
}
.size-row {
  display: flex;
  align-items: center;
  gap: 6px;
  min-width: 0;
}
.sizes {
  display: flex;
  gap: 5px;
  overflow-x: auto;
  scrollbar-width: none;
  padding: 2px;
  margin: -2px;
}
.sizes::-webkit-scrollbar {
  display: none;
}
.sizes button {
  flex: none;
  min-width: 38px;
  height: 38px;
  padding: 0 8px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--bg-2);
  font: 600 0.95rem/1 var(--mono);
  cursor: pointer;
}
.sizes button:hover {
  border-color: var(--line-2);
}
.sizes button[aria-checked="true"] {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--bg);
}
.custom input {
  width: 58px;
  height: 38px;
  padding: 0 6px;
  border: 1px dashed var(--line-2);
  border-radius: 10px;
  background: none;
  font: 600 0.95rem/1 var(--mono);
  text-align: center;
  -moz-appearance: textfield;
  appearance: textfield;
}
.custom input::-webkit-outer-spin-button,
.custom input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}
.custom input.on {
  border-style: solid;
  border-color: var(--ink);
  box-shadow: inset 0 0 0 1px var(--ink);
}

.tabs {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: 1fr;
  gap: 2px;
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--bg-2);
}
.tabs button {
  border: 0;
  border-radius: 9px;
  background: none;
  padding: 7px 4px;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--ink-3);
  cursor: pointer;
}
.tabs button[aria-selected="true"] {
  background: var(--panel);
  color: var(--ink);
  box-shadow: 0 0 0 1px var(--line-2);
}
.narrow-only {
  display: none;
}

textarea {
  display: block;
  width: 100%;
  resize: none;
  /* Six whole lines, none cut: the lines, the padding and the border. */
  height: calc(6 * 1.45em + 20px);
  padding: 9px 11px;
  border: 1px solid var(--line);
  border-radius: 11px;
  background: var(--bg);
  font: 500 0.95rem/1.45 var(--mono);
}
textarea::placeholder {
  color: var(--ink-3);
  opacity: 0.7;
}
textarea.bad {
  border-color: var(--danger);
}

.row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 8px;
}

/* The "i" beside the scramble's buttons, and what it opens. */
.button.info {
  margin-left: auto;
  width: 36px;
  padding: 0;
  border-radius: 50%;
  font: italic 600 1rem/1 Georgia, "Times New Roman", serif;
  color: var(--ink-2);
}
.button.info[aria-expanded="true"] {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--panel);
}
.help {
  position: absolute;
  left: 12px;
  right: 12px;
  z-index: 6;
  padding: 10px 12px;
  border: 1px solid var(--line-2);
  border-radius: 12px;
  background: var(--panel);
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.2);
  font-size: 0.84rem;
  line-height: 1.45;
  color: var(--ink-2);
}
.help[hidden] {
  display: none;
}
.help p {
  margin: 0;
}
.help p + p {
  margin-top: 6px;
}
.help code {
  font: 600 0.95em/1 var(--mono);
  color: var(--ink);
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 36px;
  padding: 6px 12px;
  border: 1px solid var(--line-2);
  border-radius: 10px;
  background: none;
  font-weight: 600;
  font-size: 0.88rem;
  cursor: pointer;
  white-space: nowrap;
}
.button:hover:not(:disabled) {
  background: var(--bg-2);
}
.button:disabled {
  opacity: 0.45;
  cursor: default;
}
.button.small {
  min-height: 28px;
  padding: 2px 10px;
  font-size: 0.8rem;
}
.button.quiet {
  min-height: 32px;
  padding: 4px 10px;
  font-weight: 500;
  font-size: 0.82rem;
  color: var(--ink-2);
}
.button.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
}
.button.primary:hover:not(:disabled) {
  background: var(--accent);
  filter: brightness(1.08);
}
.button.large {
  flex: 1;
  min-height: 46px;
  font-size: 1.02rem;
  border-radius: 12px;
}
.button[aria-pressed="true"] {
  background: var(--bg-2);
  border-color: var(--ink-3);
  color: var(--ink);
}

/* Whether the cube as it stands can be solved: one line, always there. */
.valid {
  margin: 0;
  height: 1.35em;
  font-size: 0.84rem;
  line-height: 1.35;
  color: var(--ink-3);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.valid::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 8px;
  margin-right: 7px;
  border-radius: 50%;
  background: var(--line-2);
}
.valid.ok::before {
  background: var(--ok);
}
.valid.bad::before {
  background: var(--danger);
}
.valid.bad {
  color: var(--danger);
}
.valid a {
  color: var(--ink);
}
.valid b {
  font-weight: 650;
  color: var(--ink-2);
}

.go {
  display: flex;
  gap: 8px;
  align-items: stretch;
}
.modes {
  display: inline-flex;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 3px;
  background: var(--bg-2);
}
.modes button {
  border: 0;
  border-radius: 9px;
  background: none;
  padding: 0 11px;
  font-weight: 600;
  font-size: 0.86rem;
  color: var(--ink-3);
  cursor: pointer;
}
.modes button[aria-checked="true"] {
  background: var(--panel);
  color: var(--ink);
  box-shadow: 0 0 0 1px var(--line-2);
}
.modes button:disabled {
  opacity: 0.4;
  cursor: default;
}

/* Painting: the colours, and the cube unfolded to choose a face from. */
.paint {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(96px, 0.5fr);
  gap: 12px;
  align-items: center;
}
.swatches {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 5px;
}
.swatch {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: center;
  gap: 6px;
  padding: 5px 6px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: none;
  cursor: pointer;
  min-width: 0;
}
.swatch .chip {
  width: 26px;
  height: 26px;
  border-radius: 7px;
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, 0.25);
}
.swatch .count {
  font: 500 0.72rem/1 var(--mono);
  color: var(--ink-3);
  text-align: left;
}
.swatch[aria-checked="true"] {
  border-color: var(--ink);
  box-shadow: inset 0 0 0 1px var(--ink);
  background: var(--bg-2);
}
.swatch.full .count {
  color: var(--ok);
}
.swatch.over .count {
  color: var(--danger);
  font-weight: 700;
}
.net {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-template-rows: repeat(3, auto);
  gap: 3px;
}
.net-face {
  aspect-ratio: 1;
  display: grid;
  grid-template-columns: repeat(var(--cells), 1fr);
  gap: 1px;
  padding: 2px;
  border: 0;
  border-radius: 5px;
  background: var(--cube-body);
  cursor: pointer;
  opacity: 0.75;
}
.net-face i {
  border-radius: 1.5px;
  background: var(--cube-blank);
}
.net-face.current {
  opacity: 1;
  box-shadow: 0 0 0 2px var(--ink);
}
.net-face.doubt:not(.current) {
  box-shadow: 0 0 0 1.5px var(--danger);
}

/* The camera's side of the panel. */
.private {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 9px;
  align-items: start;
  margin: 10px 0 12px;
  padding: 9px 11px;
  border: 1px solid color-mix(in srgb, var(--ok) 45%, var(--line));
  border-radius: 11px;
  font-size: 0.84rem;
  color: var(--ink-2);
}
.private svg {
  width: 18px;
  height: 18px;
  margin-top: 1px;
  fill: none;
  stroke: var(--ok);
  stroke-width: 1.8;
  stroke-linejoin: round;
}
.cam-scan {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
}
.cam-side {
  display: grid;
  gap: 8px;
  min-width: 0;
}
.cam-say {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 10px;
  align-items: start;
}
/* The small drawings of what to do with the cube: one, or two with "then" between them. */
.cam-sign {
  display: flex;
  align-items: center;
  gap: 3px;
  color: var(--ink);
}
.cam-sign svg {
  display: block;
  width: 46px;
  height: 44px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2.4;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.cam-sign svg .head {
  fill: currentColor;
  stroke-width: 1.2;
}
.cam-sign i {
  font: 600 0.62rem/1 var(--sans);
  font-style: normal;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.cam-text.warn {
  color: var(--danger);
}
.cam-heading {
  margin: 0 0 2px;
  font-weight: 700;
  font-size: 0.98rem;
}
.cam-text {
  margin: 0;
  color: var(--ink-2);
  font-size: 0.86rem;
  line-height: 1.35;
  min-height: 2.7em;
}
.cam-shots {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 5px;
  margin: 0;
  /* Room for the frame round the face in hand, which is drawn outside it:
     without it the box this strip scrolls in cuts the frame's left side. */
  padding: 3px;
  list-style: none;
  max-width: 330px;
}
.cam-shots li {
  aspect-ratio: 1;
  display: grid;
  grid-template-columns: repeat(var(--n), 1fr);
  gap: 1px;
  padding: 2px;
  border-radius: 6px;
  background: var(--cube-body);
  opacity: 0.55;
}
.cam-shots li i {
  border-radius: 1px;
  background: var(--cube-blank);
}
.cam-shots li {
  cursor: pointer;
}
.cam-shots li:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.cam-shots li.taken {
  opacity: 1;
}
.cam-shots li.current {
  opacity: 1;
  box-shadow: 0 0 0 2px var(--accent);
}
.cam-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
}
.cam-buttons .primary {
  flex: 1 1 110px;
  min-height: 42px;
}

/* ------------------------------------------------------ narrow screens */

@media (max-width: 759px) {
  :root {
    --gutter: 10px;
  }
  body {
    font-size: 14px;
  }
  .top {
    gap: 8px;
    padding: 5px 0;
  }
  /* The header holds the sizes (app.js moves them there); the words make room. */
  .brand span,
  .top-extra,
  .stage-size,
  .wide-only,
  .tool span {
    display: none;
  }
  .top .size-row {
    flex: 1;
  }
  .sizes button,
  .custom input {
    height: 34px;
    min-width: 34px;
  }
  .custom input {
    width: 46px;
  }
  .bench {
    grid-template-columns: minmax(0, 1fr);
    grid-template-rows: minmax(0, 1fr) auto;
    gap: 8px;
    padding-bottom: 8px;
  }
  .stage-col {
    gap: 6px;
  }
  /* The solution is a tab here, and the cube the camera reads sits beside its buttons. */
  .lower {
    display: none;
  }
  .cam-scan {
    grid-template-columns: minmax(0, 1fr) 86px;
    align-items: center;
  }
  .scan-slot-narrow {
    display: grid;
    aspect-ratio: 1;
    border: 1px solid var(--line);
    border-radius: 10px;
    background: radial-gradient(120% 90% at 50% 28%, var(--stage-a), var(--stage-b) 72%);
  }
  .next {
    top: 8px;
    left: 10px;
  }
  .panel {
    padding: 8px;
    gap: 7px;
    border-radius: var(--radius);
  }
  .narrow-only {
    display: block;
  }
  .panels {
    height: 150px;
  }
  textarea {
    height: calc(4 * 1.45em + 16px);
    padding: 7px 9px;
  }
  .row {
    margin-top: 6px;
    flex-wrap: nowrap;
  }
  .note {
    margin-top: 5px;
    font-size: 0.78rem;
  }
  .tabpanel > .note:first-child {
    margin-bottom: 4px;
  }
  /* Paint holds its sentence (two lines at most), the colours with the
     unfolded cube, and its two buttons, with nothing left to scroll to. */
  .paint + .row {
    margin-top: 4px;
  }
  .private {
    margin: 4px 0 6px;
    padding: 4px 8px;
    font-size: 0.78rem;
  }
  /* The solution as a tab: its moves in the tab's own height. */
  .solution {
    border: 0;
    padding: 0;
    background: none;
    height: 150px;
  }
  .valid {
    font-size: 0.8rem;
  }
  .paint {
    grid-template-columns: minmax(0, 1fr) 92px;
    gap: 8px;
  }
  .swatch {
    padding: 4px 5px;
  }
  .swatch .chip {
    width: 22px;
    height: 22px;
  }
  .cam-heading {
    font-size: 0.9rem;
    margin: 0;
  }
  .cam-say {
    gap: 6px;
  }
  .cam-sign svg {
    width: 32px;
    height: 31px;
  }
  .cam-sign i {
    display: none;
  }
  .cam-text {
    min-height: 0;
    font-size: 0.78rem;
    line-height: 1.3;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
  }
  .cam-shots {
    max-width: 190px;
    gap: 4px;
  }
  .cam-buttons {
    flex-wrap: nowrap;
    gap: 4px;
  }
  .cam-buttons .button {
    min-height: 32px;
    padding: 2px 7px;
    font-size: 0.78rem;
  }
  .cam-buttons .primary {
    flex: 1 1 60px;
    min-height: 34px;
  }
  .cam-side {
    gap: 5px;
  }
  .cam-buttons .primary {
    min-height: 36px;
  }
  .button.large {
    min-height: 42px;
  }
}

/* A screen that is short as well as wide (a small laptop): tighter rows. */
@media (min-width: 760px) and (max-height: 640px) {
  .panels {
    height: 176px;
  }
  textarea {
    height: calc(5 * 1.45em + 20px);
  }
  .panel {
    gap: 8px;
    padding: 10px;
  }
}

@media (prefers-reduced-motion: reduce) {
  span.busy i {
    animation: none;
    opacity: 0.8;
  }
}

/* A phone too narrow for "Random scramble" beside the other buttons says "Random". */
@media (max-width: 430px) {
  #random .long {
    display: none;
  }
  .row {
    gap: 5px;
  }
}