/* Poople Map — deep-space observatory look. One committed dark theme:
   the graph is a glowing constellation, the panel is the control deck. */

:root {
  --color-bg: oklch(16% 0.03 280);
  --color-panel: oklch(21% 0.035 282);
  --color-panel-edge: oklch(32% 0.05 282);
  --color-text: oklch(92% 0.02 280);
  --color-text-dim: oklch(68% 0.03 280);
  --color-target: oklch(80% 0.14 80);       /* poop gold */
  --color-depth1: oklch(75% 0.12 185);      /* teal */
  --color-depth2: oklch(62% 0.17 275);      /* indigo */
  --color-depth3: oklch(65% 0.19 310);      /* violet */
  --color-ok: oklch(78% 0.14 160);
  --color-error: oklch(72% 0.16 25);

  --font-ui: "Avenir Next", "Segoe UI", system-ui, sans-serif;
  --font-mono: "SF Mono", ui-monospace, Menlo, Consolas, monospace;

  --text-base: clamp(0.9rem, 0.85rem + 0.3vw, 1rem);
  --space-panel: clamp(1rem, 0.8rem + 1vw, 1.75rem);
  --radius: 14px;
  --duration-fast: 150ms;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
}

body {
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-ui);
  font-size: var(--text-base);
  overflow: hidden;
}

.app {
  display: grid;
  grid-template-columns: minmax(280px, 340px) 1fr;
  height: 100dvh;
}

/* ---- Control panel ------------------------------------------------------ */

.panel {
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
  padding: var(--space-panel);
  background: linear-gradient(200deg, var(--color-panel), oklch(18% 0.03 282));
  border-right: 1px solid var(--color-panel-edge);
  overflow-y: auto;
  z-index: 2;
}

.brand {
  margin: 0;
  font-size: clamp(1.6rem, 1.3rem + 1vw, 2.1rem);
  letter-spacing: -0.02em;
  font-weight: 800;
}

.brand-accent {
  color: var(--color-target);
}

.tagline {
  margin: -0.6rem 0 0;
  color: var(--color-text-dim);
  line-height: 1.45;
}

.field-label {
  display: block;
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-dim);
  margin-bottom: 0.45rem;
}

.field-row {
  display: flex;
  gap: 0.5rem;
}

#word-input {
  flex: 1;
  min-width: 0;
  padding: 0.55rem 0.75rem;
  font-family: var(--font-mono);
  font-size: 1.15rem;
  letter-spacing: 0.18em;
  text-transform: lowercase;
  color: var(--color-text);
  background: oklch(14% 0.025 282);
  border: 1px solid var(--color-panel-edge);
  border-radius: 10px;
  transition: border-color var(--duration-fast) var(--ease-out),
              box-shadow var(--duration-fast) var(--ease-out);
}

#word-input:focus-visible {
  outline: none;
  border-color: var(--color-target);
  box-shadow: 0 0 0 3px oklch(80% 0.14 80 / 0.25);
}

.btn {
  padding: 0.55rem 0.9rem;
  font: inherit;
  font-weight: 600;
  color: var(--color-text);
  background: oklch(28% 0.04 282);
  border: 1px solid var(--color-panel-edge);
  border-radius: 10px;
  cursor: pointer;
  transition: transform var(--duration-fast) var(--ease-out),
              background var(--duration-fast) var(--ease-out),
              box-shadow var(--duration-fast) var(--ease-out);
}

.btn:hover { background: oklch(33% 0.05 282); transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn:focus-visible {
  outline: 2px solid var(--color-target);
  outline-offset: 2px;
}

.btn--primary {
  background: var(--color-target);
  border-color: transparent;
  color: oklch(20% 0.05 80);
}
.btn--primary:hover {
  background: oklch(85% 0.14 82);
  box-shadow: 0 4px 18px oklch(80% 0.14 80 / 0.35);
}

.btn--ghost {
  background: transparent;
  align-self: flex-start;
}

#solver-message {
  min-height: 1.2em;
  margin: 0.6rem 0 0;
  font-size: 0.88rem;
  line-height: 1.4;
  color: var(--color-text-dim);
}
#solver-message.is-ok { color: var(--color-ok); }
#solver-message.is-error { color: var(--color-error); }

/* ---- Path chips ---------------------------------------------------------- */

#path-chips {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem;
  margin-top: 0.5rem;
}

.chip {
  padding: 0.3rem 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  letter-spacing: 0.12em;
  background: oklch(27% 0.05 275);
  border: 1px solid oklch(40% 0.08 275);
  border-radius: 999px;
}

.chip--target {
  background: oklch(32% 0.08 80);
  border-color: var(--color-target);
  color: var(--color-target);
  font-weight: 700;
}

.chip-diff {
  color: var(--color-target);
  font-weight: 800;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.chip-arrow { color: var(--color-text-dim); }

/* ---- Depth + legend + stats ---------------------------------------------- */

.control { margin-top: 0.25rem; }

#depth-slider {
  width: 100%;
  accent-color: var(--color-target);
}

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 0.85rem;
  color: var(--color-text-dim);
}

.legend li { display: flex; align-items: center; gap: 0.4rem; }

.dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  box-shadow: 0 0 8px currentColor;
}
.dot--0 { background: var(--color-target); color: var(--color-target); }
.dot--1 { background: var(--color-depth1); color: var(--color-depth1); }
.dot--2 { background: var(--color-depth2); color: var(--color-depth2); }
.dot--3 { background: var(--color-depth3); color: var(--color-depth3); }

.stats {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-text-dim);
}

.credits {
  margin-top: auto;
  font-size: 0.75rem;
  color: var(--color-text-dim);
  line-height: 1.5;
}
.credits p { margin: 0.3rem 0; }
.credits a { color: var(--color-depth1); }

/* ---- Stage ---------------------------------------------------------------- */

.stage {
  position: relative;
  overflow: hidden;
}

.stage canvas {
  display: block;
  cursor: grab;
}

.tooltip {
  position: absolute;
  padding: 0.35rem 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  white-space: nowrap;
  color: var(--color-text);
  background: oklch(22% 0.04 282 / 0.92);
  border: 1px solid var(--color-panel-edge);
  border-radius: 8px;
  pointer-events: none;
  transform: translateY(-100%);
  z-index: 3;
}

/* ---- Small screens --------------------------------------------------------- */

@media (max-width: 760px) {
  body { overflow: auto; }

  .app {
    grid-template-columns: 1fr;
    grid-template-rows: auto minmax(60dvh, 1fr);
    height: auto;
    min-height: 100dvh;
  }

  .panel {
    border-right: none;
    border-bottom: 1px solid var(--color-panel-edge);
  }

  .credits { margin-top: 0.5rem; }
}