:root {
  --paper: #f6f4ef;
  --ink: #23262b;
  --muted: #6b7078;
  --panel: rgba(255, 255, 255, 0.92);
  --line: #d9d5cc;
  --accent: #2f6feb;
  --stroke: #23262b;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #1c1e22;
    --ink: #eceef1;
    --muted: #9aa0a8;
    --panel: rgba(40, 43, 49, 0.92);
    --line: #3a3e46;
    --accent: #6ea0ff;
    --stroke: #eceef1;
  }
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
  margin: 0;
  overflow: hidden;
  overscroll-behavior: none;
}

body {
  display: flex;
  flex-direction: column;
  background: var(--paper);
  color: var(--ink);
  font: 14px/1.4 system-ui, -apple-system, "Segoe UI", sans-serif;
  -webkit-user-select: none;
  user-select: none;
}

#stage {
  position: relative;
  flex: 1;
  min-height: 0;
  order: 2;
  touch-action: none;
  cursor: crosshair;
}

#stage canvas, .layer {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
}

.layer { pointer-events: none; }

#stroke, #connector {
  fill: none;
  stroke: var(--stroke);
  stroke-width: 6;
  stroke-linecap: round;
  stroke-linejoin: round;
  opacity: 0.5;
}

#guide, #guide-under {
  fill: none;
  stroke: var(--accent);
  stroke-linecap: round;
  stroke-linejoin: round;
}

#guide-layer { opacity: 0.6; }
#guide-start, #guide-arrow { fill: var(--accent); }

#coach {
  position: absolute;
  top: 12px;
  left: 12px;
  width: min(340px, calc(100% - 24px));
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--panel);
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.18);
  cursor: default;
}

#coach p { margin: 0 0 8px; }
#coach-step { color: var(--accent); font-weight: 600; font-size: 12px; text-transform: uppercase; letter-spacing: 0.04em; }
#coach button { height: 30px; }

#wedge {
  fill: var(--accent);
  fill-opacity: 0.12;
  stroke: var(--accent);
  stroke-dasharray: 4 4;
}

#hint, #count {
  position: absolute;
  margin: 0;
  bottom: 10px;
  color: var(--muted);
  pointer-events: none;
}

#hint { left: 12px; right: 110px; }
#count { right: 12px; font-variant-numeric: tabular-nums; }

#toolbar {
  order: 1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px 12px;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
}

/* Buttons and dropdowns share one box. Dropdowns drop the browser's own
   chrome, which Safari sizes differently from a button, and draw their arrow. */
button, select {
  box-sizing: border-box;
  height: 34px;
  margin: 0;
  padding: 0 12px;
  font: inherit;
  line-height: 1;
  color: inherit;
  border: 1px solid var(--line);
  border-radius: 8px;
  background-color: transparent;
  cursor: pointer;
  white-space: nowrap;
  -webkit-appearance: none;
  appearance: none;
}

select {
  padding-right: 28px;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 10 6'%3E%3Cpath d='M1 1l4 4 4-4' fill='none' stroke='%23888' stroke-width='1.6' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
  background-size: 10px 6px;
  text-overflow: ellipsis;
}

button:hover { border-color: var(--muted); }
button:focus-visible, select:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }
button:disabled { opacity: 0.4; cursor: default; }

button[aria-pressed="true"] {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

#tighten { min-width: 5.5em; }

#examples { width: 8.5em; }
#more { width: 6em; }

.select {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--muted);
}

dialog {
  max-width: min(560px, calc(100vw - 32px));
  max-height: calc(100vh - 32px);
  padding: 20px 24px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--paper);
  color: var(--ink);
  -webkit-user-select: text;
  user-select: text;
}

dialog::backdrop { background: rgba(0, 0, 0, 0.4); }
dialog h2 { margin: 0 0 8px; font-size: 18px; }
dialog h3 { margin: 14px 0 4px; font-size: 14px; }
dialog ul { margin: 0; padding-left: 18px; }
dialog li { margin: 4px 0; }
dialog form { margin-top: 16px; text-align: right; }

kbd {
  padding: 1px 5px;
  border: 1px solid var(--line);
  border-radius: 4px;
  font: inherit;
}

/* Phones: the tools move under the thumb. */
@media (max-width: 720px) {
  #toolbar {
    order: 3;
    border-bottom: 0;
    border-top: 1px solid var(--line);
    padding: 8px 8px calc(8px + env(safe-area-inset-bottom));
  }
  button, select { height: 44px; }
  button { padding: 0 10px; }
  select { padding-left: 10px; }
  .select { font-size: 0; gap: 0; }
  .select select { font-size: 14px; }
  #hint { right: 12px; bottom: 8px; font-size: 13px; }
  #count { bottom: auto; top: 8px; }
}