:root {
  color-scheme: dark;
  --bg: #080b0f;
  --bg-2: #10161d;
  --panel: #141b24;
  --panel-2: #1b2430;
  --stroke: #2a3646;
  --stroke-2: #3d4d62;
  --text: #e8eef6;
  --muted: #8b9aab;
  --a: #3ec4ff;
  --b: #ffb020;
  --c: #d060ff;
  --accent: #5ee0c0;
  --on-accent: #08201a;
  --danger: #ff6b7a;
  --shadow: 0 18px 50px rgba(0, 0, 0, 0.35);
  --radius: 16px;
  --font: "Instrument Sans", system-ui, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, monospace;
  --topbar: linear-gradient(180deg, #121922 0%, #0c1117 100%);
  --viewport-glow: #152033;
  --overlay: rgba(20, 27, 36, 0.82);
  --plot: #1b2430;
  --slider: #2a3544;
  --thumb-border: #0c1117;
  --switch: #2c3848;
  --switch-knob: #d7e2ee;
  --switch-on: #1f6d5c;
  --grip: #6d7e90;
  --scene-bg: #080b0f;
  --box-fill: #8eb4d4;
  --box-edge: #6f889e;
  --grid-major: #35506a;
  --grid-minor: #243140;
  --mb: #5ee0c0;
  --plot-label: #8b9aab;
}

html[data-theme="light"] {
  color-scheme: light;
  --bg: #eef2f6;
  --bg-2: #ffffff;
  --panel: #e4eaf1;
  --panel-2: #f4f7fb;
  --stroke: #c5d0dc;
  --stroke-2: #8fa0b3;
  --text: #15202b;
  --muted: #5b6b7c;
  --a: #0284c7;
  --b: #d97706;
  --c: #9333ea;
  --accent: #0f9d82;
  --on-accent: #f4fffb;
  --danger: #dc3d52;
  --shadow: 0 16px 40px rgba(21, 40, 62, 0.12);
  --topbar: linear-gradient(180deg, #ffffff 0%, #eef2f6 100%);
  --viewport-glow: #d7e4f2;
  --overlay: rgba(255, 255, 255, 0.82);
  --plot: #f4f7fb;
  --slider: #cdd6e1;
  --thumb-border: #ffffff;
  --switch: #c5d0dc;
  --switch-knob: #ffffff;
  --switch-on: #0f9d82;
  --grip: #8fa0b3;
  --scene-bg: #e8eef4;
  --box-fill: #4d6f8c;
  --box-edge: #3d5670;
  --grid-major: #7b93ab;
  --grid-minor: #c5d3e0;
  --mb: #0f9d82;
  --plot-label: #5b6b7c;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  overflow: hidden;
}

button,
input {
  font-family: inherit;
}

#app {
  height: 100%;
  display: grid;
  grid-template-rows: auto 1fr;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 20px 10px;
  border-bottom: 1px solid var(--stroke);
  background: var(--topbar);
}

.brand {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.brand h1 {
  margin: 0;
  font-size: 18px;
  font-weight: 620;
  letter-spacing: 0.01em;
}

.brand p {
  margin: 0;
  color: var(--muted);
  font-size: 12.5px;
}

.equation {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 10%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent) 28%, transparent);
  border-radius: 999px;
  padding: 7px 12px;
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.theme-btn {
  width: 38px;
  height: 38px;
  border-radius: 11px;
  border: 1px solid var(--stroke-2);
  background: var(--bg-2);
  color: var(--text);
  display: grid;
  place-items: center;
  cursor: pointer;
}

.theme-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.theme-btn .icon-moon {
  display: none;
}

html[data-theme="light"] .theme-btn .icon-sun {
  display: none;
}

html[data-theme="light"] .theme-btn .icon-moon {
  display: block;
}

.stage {
  position: relative;
  min-height: 0;
  display: grid;
  grid-template-columns: 1fr 360px;
}

.viewport {
  position: relative;
  min-width: 0;
  min-height: 0;
  background:
    radial-gradient(ellipse at 50% 30%, var(--viewport-glow) 0%, transparent 55%),
    var(--bg);
}

.viewport canvas {
  position: absolute;
  inset: 0;
  display: block;
  width: 100%;
  height: 100%;
  touch-action: none;
  z-index: 0;
}

.overlay {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 1;
}

.overlay > * {
  pointer-events: auto;
}

.view-btn {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 42px;
  height: 42px;
  border: 1px solid var(--stroke-2);
  background: var(--overlay);
  color: var(--text);
  border-radius: 12px;
  display: grid;
  place-items: center;
  cursor: pointer;
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow);
}

.view-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.legend {
  position: absolute;
  left: 16px;
  top: 16px;
  display: flex;
  gap: 8px;
  padding: 8px;
  border-radius: 14px;
  background: var(--overlay);
  border: 1px solid var(--stroke);
  backdrop-filter: blur(10px);
}

.chip {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 4px 8px;
  font-size: 12px;
  color: var(--muted);
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  box-shadow: 0 0 10px currentColor;
}

.dot.a { color: var(--a); background: var(--a); }
.dot.b { color: var(--b); background: var(--b); }
.dot.c { color: var(--c); background: var(--c); }

.hint {
  position: absolute;
  left: 16px;
  bottom: 16px;
  font-size: 12px;
  color: var(--muted);
  background: var(--overlay);
  border: 1px solid var(--stroke);
  padding: 8px 10px;
  border-radius: 10px;
}

.controls {
  min-height: 0;
  overflow: auto;
  background: var(--panel);
  border-left: 1px solid var(--stroke);
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  position: relative;
  z-index: 2;
}

.controls.drop-target {
  background: color-mix(in srgb, var(--accent) 8%, var(--panel));
}

.dock-hint {
  display: none;
  margin: 0;
  padding: 18px 12px;
  text-align: center;
  color: var(--muted);
  font-size: 12px;
  border: 1px dashed var(--stroke-2);
  border-radius: var(--radius);
}

.dock-hint.visible {
  display: block;
}

.card-placeholder {
  min-height: 56px;
  border: 1px dashed color-mix(in srgb, var(--accent) 55%, transparent);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--accent) 8%, transparent);
  flex: 0 0 auto;
}

.float-layer {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 6;
}

.card {
  position: relative;
  background: var(--bg-2);
  border: 1px solid var(--stroke);
  border-radius: var(--radius);
  padding: 0;
  display: flex;
  flex-direction: column;
  min-width: 0;
  flex: 0 0 auto;
}

.card.dock-sized {
  overflow: hidden;
}

.card.floating {
  position: absolute;
  pointer-events: auto;
  margin: 0;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.card.dragging {
  opacity: 0.96;
  cursor: grabbing;
}

.card-head {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 11px 12px 11px 10px;
  cursor: grab;
  user-select: none;
  touch-action: none;
  flex: 0 0 auto;
}

.card.dragging .card-head,
.card-head:active {
  cursor: grabbing;
}

.card:not(.collapsed) .card-head {
  border-bottom: 1px solid var(--stroke);
}

.card-grip {
  width: 12px;
  height: 16px;
  flex: 0 0 auto;
  background-image: radial-gradient(circle, var(--grip) 1.15px, transparent 1.25px);
  background-size: 6px 6px;
  background-position: 0 1px;
  opacity: 0.85;
}

.card h2 {
  margin: 0;
  flex: 1;
  font-size: 11px;
  font-weight: 650;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.card-toggle {
  width: 28px;
  height: 28px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  position: relative;
  flex: 0 0 auto;
}

.card-toggle:hover {
  background: var(--panel-2);
  color: var(--text);
}

.card-toggle::before {
  content: "";
  position: absolute;
  left: 10px;
  top: 8px;
  width: 7px;
  height: 7px;
  border-right: 1.8px solid currentColor;
  border-bottom: 1.8px solid currentColor;
  transform: rotate(45deg);
  transition: transform 0.15s ease;
}

.card.collapsed .card-toggle::before {
  top: 10px;
  transform: rotate(-45deg);
}

.card-body {
  padding: 14px;
  min-height: 0;
  overflow: auto;
}

.card.collapsed .card-body,
.card.collapsed .card-resize {
  display: none;
}

.card.floating:not(.collapsed) .card-body,
.card.dock-sized:not(.collapsed) .card-body {
  flex: 1;
}

.card-resize {
  position: absolute;
  right: 2px;
  bottom: 2px;
  width: 16px;
  height: 16px;
  cursor: ns-resize;
  touch-action: none;
}

.card.floating .card-resize {
  cursor: nwse-resize;
}

.card-resize::before {
  content: "";
  position: absolute;
  right: 4px;
  bottom: 4px;
  width: 9px;
  height: 9px;
  border-right: 1.6px solid var(--stroke-2);
  border-bottom: 1.6px solid var(--stroke-2);
}

.energy-body {
  display: flex;
  flex-direction: column;
  min-height: 180px;
}

.energy-stats {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 8px;
  font-size: 11px;
  color: var(--muted);
}

.energy-stats b {
  font-family: var(--mono);
  color: var(--text);
  font-weight: 500;
}

#energy-dist {
  width: 100%;
  flex: 1;
  min-height: 140px;
  height: 160px;
  display: block;
  background: var(--plot);
  border-radius: 10px;
}

.energy-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 14px;
  margin-top: 8px;
  font-size: 11px;
  color: var(--muted);
}

.energy-legend span,
.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
}

.legend-item {
 margin: 0;
  padding: 2px 6px 2px 4px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--muted);
  font: inherit;
  cursor: pointer;
}

.legend-item:hover {
  background: var(--panel-2);
  color: var(--text);
}

.legend-item[aria-pressed="false"] {
  opacity: 0.38;
  text-decoration: line-through;
  text-decoration-color: var(--muted);
}

.swatch {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  display: inline-block;
}

.swatch.a { background: var(--a); }
.swatch.b { background: var(--b); }
.swatch.mb {
  height: 2px;
  width: 14px;
  border-radius: 0;
  background: var(--mb);
}

.swatch.reactive {
  width: 12px;
  height: 10px;
  border-radius: 2px;
  background: color-mix(in srgb, var(--danger) 45%, transparent);
  box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--danger) 70%, transparent);
}

.swatch.ea {
  width: 4px;
  height: 12px;
  border-radius: 1px;
  background: var(--danger);
}

.playback {
  display: grid;
  grid-template-columns: auto auto 1fr;
  gap: 8px;
  align-items: center;
}

.icon-btn {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  border: 1px solid var(--stroke-2);
  background: var(--panel-2);
  color: var(--text);
  display: grid;
  place-items: center;
  cursor: pointer;
}

.icon-btn:hover,
.icon-btn.active {
  border-color: var(--accent);
  color: var(--accent);
}

.icon-btn:disabled {
  opacity: 0.35;
  cursor: default;
}

.icon-btn.primary {
  background: var(--accent);
  color: var(--on-accent);
  border-color: transparent;
}

.icon-btn.primary:hover {
  color: var(--on-accent);
  filter: brightness(1.05);
}

.time-row {
  display: flex;
  justify-content: space-between;
  margin-top: 8px;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 999px;
  background: var(--slider);
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--text);
  border: 2px solid var(--thumb-border);
  cursor: pointer;
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 18%, transparent);
}

.slider-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 8px;
}

.slider-head + input[type="range"] + .slider-head {
  margin-top: 12px;
}

.slider-head label {
  font-size: 13px;
}

.value {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--accent);
}

.value.a { color: var(--a); }
.value.b { color: var(--b); }
.value.c { color: var(--c); }

.toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.toggle span {
  font-size: 13px;
}

.switch {
  position: relative;
  width: 44px;
  height: 26px;
  flex: 0 0 auto;
}

.switch input {
  position: absolute;
  opacity: 0;
  width: 44px;
  height: 26px;
  margin: 0;
  cursor: pointer;
  z-index: 1;
}

.knob {
  position: absolute;
  inset: 0;
  background: var(--switch);
  border-radius: 999px;
  cursor: pointer;
  transition: 0.15s ease;
}

.knob::after {
  content: "";
  position: absolute;
  width: 20px;
  height: 20px;
  left: 3px;
  top: 3px;
  background: var(--switch-knob);
  border-radius: 50%;
  transition: 0.15s ease;
}

.switch input:checked + .knob {
  background: var(--switch-on);
}

.switch input:checked + .knob::after {
  transform: translateX(18px);
  background: var(--accent);
}

.ea-grid {
  display: grid;
  gap: 12px;
}

.ea-grid.disabled .rev-only {
  opacity: 0.38;
  pointer-events: none;
}

.energy {
  width: 100%;
  height: 118px;
  margin-top: 12px;
  display: block;
}

.counts {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  margin-bottom: 10px;
}

.stat {
  background: var(--panel-2);
  border: 1px solid var(--stroke);
  border-radius: 12px;
  padding: 8px;
  text-align: center;
}

.stat b {
  display: block;
  font-family: var(--mono);
  font-size: 20px;
  line-height: 1.2;
}

.stat span {
  font-size: 11px;
  color: var(--muted);
}

.stat.a b { color: var(--a); }
.stat.b b { color: var(--b); }
.stat.c b { color: var(--c); }

.rates {
  margin-bottom: 10px;
}

.rates .stat b {
  font-size: 16px;
}

.rates .stat.muted {
  opacity: 0.4;
}

.card[data-card="composition"] .card-body {
  display: flex;
  flex-direction: column;
}

#chart {
  width: 100%;
  height: 84px;
  min-height: 72px;
  display: block;
}

.card.floating[data-card="composition"] #chart,
.card.dock-sized[data-card="composition"] #chart {
  flex: 1;
  height: auto;
}

.card.floating .energy-body #energy-dist,
.card.dock-sized .energy-body #energy-dist {
  height: auto;
}

.reset-row {
  display: flex;
  gap: 8px;
}

.text-btn {
  flex: 1;
  height: 38px;
  border-radius: 10px;
  border: 1px solid var(--stroke-2);
  background: var(--panel-2);
  color: var(--text);
  cursor: pointer;
}

.text-btn:hover {
  border-color: var(--accent);
}

.note {
  margin: 8px 0 0;
  font-size: 12px;
  color: var(--muted);
  line-height: 1.45;
}

@media (max-width: 980px) {
  html,
  body {
    overflow: auto;
  }

  #app {
    height: auto;
    min-height: 100%;
  }

  .stage {
    grid-template-columns: 1fr;
    grid-template-rows: minmax(52vh, 62vh) auto;
  }

  .controls {
    border-left: 0;
    border-top: 1px solid var(--stroke);
    max-height: 48vh;
  }
}