:root {
  --panel-width: 330px;
  --bg: #eef6fb;
  --basin-bg: #d9edf7;
  --basin-deep: #8bc4de;
  --ink: #102333;
  --muted: #5c7282;
  --panel: rgba(255, 255, 255, 0.92);
  --panel-border: rgba(32, 72, 102, 0.16);
  --card: rgba(247, 251, 253, 0.96);
  --card-border: rgba(32, 72, 102, 0.16);
  --control: #e8f2f7;
  --control-border: rgba(32, 72, 102, 0.22);
  --accent: #2f8dc7;
  --accent-strong: #176c9e;
  --danger: #b94d41;
  --shadow: rgba(25, 57, 82, 0.16);
}

* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  height: 100%;
  margin: 0;
  overflow: hidden;
  color: var(--ink);
  background: var(--bg);
  font-family: "Lato", sans-serif;
}

body {
  padding-top: var(--sim-nav-offset, 44px);
}

button,
input {
  font: inherit;
}

button {
  color: inherit;
}

#root {
  height: calc(100dvh - var(--sim-nav-offset, 44px));
  min-height: 0;
}

.density-app {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) var(--panel-width);
  width: 100%;
  height: 100%;
  overflow: hidden;
  background:
    radial-gradient(circle at 18% 12%, rgba(255, 255, 255, 0.9), transparent 24%),
    linear-gradient(180deg, #edf8fc 0%, #cde7f2 100%);
}

.sim-stage {
  position: relative;
  min-width: 0;
  min-height: 0;
  overflow: hidden;
}

.density-canvas {
  display: block;
  width: 100%;
  height: 100%;
  touch-action: none;
  cursor: crosshair;
}

.density-canvas.dragging {
  cursor: grabbing;
}

.drop-hint {
  position: absolute;
  left: 50%;
  bottom: 13%;
  transform: translateX(-50%);
  padding: 7px 11px;
  border: 1px solid rgba(255, 255, 255, 0.7);
  border-radius: 8px;
  background: rgba(13, 51, 78, 0.58);
  color: #f4fbff;
  font-size: 0.82rem;
  font-weight: 700;
  pointer-events: none;
  opacity: 0;
  transition: opacity 120ms ease;
}

.drop-hint.visible {
  opacity: 1;
}

.control-panel {
  z-index: 4;
  display: flex;
  flex-direction: column;
  gap: 12px;
  min-height: 0;
  padding: 14px;
  overflow-y: auto;
  border-left: 1px solid var(--panel-border);
  background: var(--panel);
  box-shadow: -12px 0 30px var(--shadow);
  backdrop-filter: blur(10px);
}

.panel-section {
  padding: 12px;
  border: 1px solid var(--card-border);
  border-radius: 8px;
  background: var(--card);
}

.panel-title {
  margin: 0 0 10px;
  font-size: 0.95rem;
  font-weight: 800;
  letter-spacing: 0.01em;
}

.density-readout {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 12px;
  padding: 9px 10px;
  border-radius: 8px;
  background: var(--control);
  border: 1px solid var(--control-border);
}

.density-readout strong {
  font-family: "JetBrains Mono", monospace;
  font-size: 1.16rem;
}

.density-readout span {
  color: var(--muted);
  font-size: 0.78rem;
  text-align: right;
}

.slider-row {
  display: grid;
  gap: 6px;
  margin-top: 10px;
}

.slider-row label {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  color: var(--muted);
  font-size: 0.8rem;
  font-weight: 700;
}

.slider-row output {
  color: var(--ink);
  font-family: "JetBrains Mono", monospace;
}

.slider-row input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

.object-list {
  display: grid;
  gap: 8px;
}

.object-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.object-card.used {
  opacity: 0.35;
  filter: grayscale(1);
  pointer-events: none;
  cursor: default;
}

.object-mystery {
  display: flex;
  justify-content: center;
}

.object-mystery .object-card {
  max-width: calc(50% - 4px);
}

.object-card {
  display: grid;
  gap: 6px;
  justify-items: center;
  width: 100%;
  padding: 12px 8px 10px;
  border: 1px solid var(--card-border);
  border-radius: 10px;
  background: #ffffff;
  text-align: center;
  cursor: grab;
  user-select: none;
  transition: border-color 120ms ease, transform 120ms ease, box-shadow 120ms ease;
}

.object-card:hover {
  border-color: rgba(47, 141, 199, 0.6);
  box-shadow: 0 8px 18px var(--shadow);
  transform: translateY(-1px);
}

.object-card:active {
  cursor: grabbing;
  transform: translateY(0);
}

.object-icon {
  position: relative;
  height: 48px;
  width: 100%;
}

.object-name {
  display: block;
  overflow-wrap: anywhere;
  font-weight: 800;
  font-size: 0.85rem;
  line-height: 1.2;
}

.object-sub {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 4px 8px;
  margin-top: 2px;
  color: var(--muted);
  font-family: "JetBrains Mono", monospace;
  font-size: 0.7rem;
}

.panel-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.toggle-btn,
.reset-btn,
.mobile-menu-btn,
.drawer-close {
  border: 1px solid var(--control-border);
  border-radius: 8px;
  background: var(--control);
  font-weight: 800;
  cursor: pointer;
}

.toggle-btn,
.reset-btn {
  min-height: 38px;
  padding: 8px 10px;
  font-size: 0.82rem;
}

.toggle-btn.active {
  border-color: var(--accent);
  background: #d8ecf8;
  color: var(--accent-strong);
}

.hint {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 0.78rem;
}

.drag-preview {
  position: fixed;
  z-index: 50;
  width: 140px;
  height: 140px;
  transform: translate(-50%, -50%);
  pointer-events: none;
  filter: drop-shadow(0 12px 24px rgba(16, 35, 51, 0.25));
}

.mobile-menu-btn {
  display: none;
  position: absolute;
  top: 12px;
  right: 12px;
  z-index: 6;
  width: 42px;
  height: 42px;
  background: rgba(255, 255, 255, 0.86);
  box-shadow: 0 8px 22px var(--shadow);
}

.drawer-close {
  display: none;
  align-self: flex-end;
  width: 34px;
  height: 34px;
}

.drawer-backdrop {
  display: none;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #08131a;
    --basin-bg: #0e2634;
    --basin-deep: #16475c;
    --ink: #e8f4fa;
    --muted: #9ab4c3;
    --panel: rgba(8, 19, 26, 0.95);
    --panel-border: rgba(187, 222, 240, 0.16);
    --card: rgba(14, 35, 47, 0.94);
    --card-border: rgba(187, 222, 240, 0.16);
    --control: #122d3d;
    --control-border: rgba(187, 222, 240, 0.18);
    --accent: #70c9ff;
    --accent-strong: #a8ddff;
    --shadow: rgba(0, 0, 0, 0.45);
  }

  .density-app {
    background:
      radial-gradient(circle at 18% 12%, rgba(255, 255, 255, 0.04), transparent 24%),
      linear-gradient(180deg, #0b1d28 0%, #061017 100%);
  }

  .object-card {
    background: rgba(20, 48, 66, 0.45);
    border-color: rgba(187, 222, 240, 0.12);
  }

  .object-card:hover {
    background: rgba(20, 48, 66, 0.75);
    border-color: rgba(112, 201, 255, 0.45);
    box-shadow: 0 8px 22px var(--shadow);
  }

  .toggle-btn:hover,
  .reset-btn:hover,
  .mobile-menu-btn:hover,
  .drawer-close:hover {
    background: rgba(112, 201, 255, 0.12);
    border-color: rgba(112, 201, 255, 0.35);
  }

  .toggle-btn.active {
    background: rgba(112, 201, 255, 0.18);
    border-color: var(--accent);
    color: var(--accent-strong);
  }

  .toggle-btn.active:hover {
    background: rgba(112, 201, 255, 0.25);
  }

  .mobile-menu-btn {
    background: rgba(14, 35, 47, 0.9);
    border: 1px solid var(--control-border);
    color: var(--ink);
  }

  .drawer-close {
    background: var(--control);
    border: 1px solid var(--control-border);
    color: var(--ink);
  }

  .drop-hint {
    background: rgba(14, 35, 47, 0.88);
    border-color: rgba(112, 201, 255, 0.35);
    color: #e8f4fa;
  }
}

@media (max-width: 820px) {
  .density-app {
    grid-template-columns: 1fr;
  }

  .mobile-menu-btn {
    display: block;
  }

  .control-panel {
    position: fixed;
    top: var(--sim-nav-offset, 44px);
    right: 0;
    bottom: 0;
    width: min(88vw, 340px);
    transform: translateX(104%);
    transition: transform 180ms ease;
    border-top: 1px solid var(--panel-border);
  }

  .control-panel.open {
    transform: translateX(0);
  }

  .drawer-close {
    display: block;
  }

  .drawer-backdrop {
    position: fixed;
    inset: var(--sim-nav-offset, 44px) 0 0 0;
    z-index: 3;
    display: block;
    background: rgba(5, 18, 27, 0.32);
    opacity: 0;
    pointer-events: none;
    transition: opacity 160ms ease;
  }

  .drawer-backdrop.open {
    opacity: 1;
    pointer-events: auto;
  }
}