Made of little things.

:root {
  font-family: ui-rounded, "Avenir Next", system-ui, sans-serif;
  font-size: 13px;
  color-scheme: light dark;
  --bg: #f5f1e7;
  --fg: #343d39;
  --primary: #387c69;
  --surface: color-mix(in srgb, var(--bg) 94%, var(--fg));
  --line: color-mix(in srgb, var(--fg) 15%, var(--bg));
  --muted: color-mix(in srgb, var(--fg) 60%, var(--bg));
}
* {
  box-sizing: border-box;
}
html,
body,
#app {
  height: 100%;
  margin: 0;
  background: var(--bg);
  color: var(--fg);
}
body {
  overflow: hidden;
  user-select: none;
}
button,
select {
  font: inherit;
  color: inherit;
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--bg);
  cursor: pointer;
}
button {
  padding: 6px 12px;
  touch-action: manipulation;
}
button:hover {
  background: var(--surface);
}
button:active {
  transform: translateY(1px);
}
button:focus-visible,
select:focus-visible {
  outline: 3px solid var(--primary);
  outline-offset: 2px;
}
button:disabled {
  opacity: 0.4;
  cursor: default;
}
#app {
  display: flex;
  flex-direction: column;
}
.topbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 12px;
  border-bottom: 1px solid var(--line);
}
.topbar select {
  border: 0;
  font-weight: 650;
  min-width: 0;
  flex: 1;
}
.topbar #solved {
  font:
    12px ui-monospace,
    monospace;
  color: var(--muted);
}
#reset {
  font-size: 22px;
  width: 40px;
  padding: 0;
}
main {
  display: flex;
  flex: 1;
  min-height: 0;
}
.board-wrap {
  position: relative;
  flex: 1;
  min-width: 0;
  min-height: 0;
  background-image: radial-gradient(var(--line) 1px, transparent 1px);
  background-size: 24px 24px;
}
canvas {
  display: block;
  width: 100%;
  height: 100%;
  touch-action: none;
}
.board-caption {
  position: absolute;
  top: 16px;
  left: 20px;
  right: 20px;
  display: flex;
  justify-content: space-between;
  pointer-events: none;
  font:
    10px ui-monospace,
    monospace;
  letter-spacing: 2px;
  color: var(--muted);
}
aside {
  flex: 0 0 250px;
  padding: 20px 16px;
  border-left: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: var(--surface);
}
.shelf-title {
  font:
    10px ui-monospace,
    monospace;
  letter-spacing: 2px;
  color: var(--muted);
  margin-bottom: 8px;
}
.add-row {
  display: flex;
  gap: 8px;
}
.add-row button {
  flex: 1;
  text-align: left;
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 58px;
}
.add-row small {
  margin-left: auto;
  color: var(--muted);
}
.ramp-icon {
  color: #b8793c;
  font-size: 27px;
}
.bumper-icon {
  color: #d87962;
  font-size: 24px;
}
.edit-row {
  display: flex;
  gap: 4px;
}
.edit-row select {
  min-width: 0;
  width: 100%;
  font-size: 11px;
}
.edit-row button {
  font-size: 22px;
  padding: 4px 10px;
}
.nudges {
  display: flex;
  gap: 4px;
  align-items: center;
}
.nudges span {
  font-size: 11px;
  color: var(--muted);
  margin-right: auto;
}
.nudges button {
  padding: 4px 9px;
}
#hint {
  color: var(--muted);
  line-height: 1.8;
  margin: 4px 0;
  flex: 1;
}
.run-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
#drop {
  background: var(--primary);
  color: white;
  border: 0;
  flex: 1;
  font-weight: 650;
  min-height: 46px;
  white-space: nowrap;
}
#retry {
  flex: 1;
  white-space: nowrap;
}
#status {
  font-size: 11px;
  color: var(--muted);
  line-height: 1.5;
  min-height: 34px;
}
#save {
  font-size: 11px;
  border: 0;
  background: transparent;
  min-height: 28px;
  color: var(--muted);
}
#celebration {
  position: absolute;
  left: 50%;
  top: 45%;
  transform: translate(-50%, -50%);
  width: 80%;
  text-align: center;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 24px;
  box-shadow: 0 8px 40px #0002;
}
#celebration[hidden] {
  display: none;
}
#celebration strong {
  display: block;
  font-size: 28px;
  font-family: Georgia, serif;
  font-style: italic;
}
#celebration span {
  display: block;
  margin: 12px 0;
  color: var(--muted);
}
#next {
  background: var(--primary);
  color: white;
}
.too-small {
  display: none;
}
@media (max-width: 650px) {
  .topbar {
    padding: 4px 8px;
  }
  main {
    flex-direction: column;
  }
  aside {
    flex: 0 0 auto;
    padding: 8px;
    border-left: 0;
    border-top: 1px solid var(--line);
    gap: 6px;
    display: grid;
    grid-template-columns: 1fr 1fr;
  }
  .shelf-title,
  .nudges,
  #hint,
  #save {
    display: none;
  }
  .add-row {
    grid-column: 1;
  }
  .add-row button {
    min-height: 44px;
    padding: 4px 8px;
    font-size: 11px;
    gap: 4px;
  }
  .edit-row {
    grid-column: 2;
  }
  .edit-row button {
    padding: 4px 7px;
  }
  .edit-row select {
    width: 55px;
  }
  .run-row {
    grid-column: 1 / -1;
    flex-wrap: nowrap;
  }
  #status {
    grid-column: 1 / -1;
    min-height: 16px;
    font-size: 10px;
  }
  .board-caption {
    top: 12px;
    left: 12px;
    right: 12px;
    font-size: 9px;
    letter-spacing: 1px;
  }
  #celebration {
    padding: 16px;
  }
  #celebration strong {
    font-size: 23px;
  }
}
@media (min-width: 1000px) {
  aside {
    flex-basis: 290px;
    padding: 28px 20px;
    gap: 16px;
  }
  .add-row button {
    min-height: 70px;
  }
}
@media (max-height: 470px) and (min-width: 651px) {
  aside {
    padding: 8px;
    gap: 4px;
  }
  .shelf-title,
  #hint,
  .nudges {
    display: none;
  }
  .add-row button {
    min-height: 44px;
  }
}
@media (max-width: 279px), (max-height: 359px) {
  #app {
    display: none;
  }
  .too-small {
    display: flex;
    height: 100%;
    padding: 12px;
    align-items: center;
    justify-content: center;
    line-height: 1.7;
    color: var(--muted);
  }
}
@media (max-width: 650px) {
  aside {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  }
  .add-row,
  .edit-row {
    min-width: 0;
  }
  .add-row button {
    min-width: 0;
    justify-content: center;
    padding: 4px;
  }
  .add-row small {
    display: none;
  }
  .ramp-icon,
  .bumper-icon {
    font-size: 20px;
  }
  .edit-row select {
    flex: 1;
    width: 0;
  }
  .edit-row button {
    flex: 0 0 28px;
    padding: 4px;
  }
  button,
  select {
    min-width: 0;
  }
}