:root {
  --bg0: #0b1020;
  --bg1: #101b34;
  --panel: rgba(255, 255, 255, 0.06);
  --panel2: rgba(255, 255, 255, 0.09);
  --text: rgba(255, 255, 255, 0.92);
  --muted: rgba(255, 255, 255, 0.72);
  --border: rgba(255, 255, 255, 0.12);
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  font: 14px/1.35 system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans,
    sans-serif;
  color: var(--text);
  background: radial-gradient(1200px 900px at 10% 0%, #1b2a55 0%, var(--bg0) 60%)
      fixed,
    linear-gradient(180deg, var(--bg1) 0%, var(--bg0) 100%) fixed;
  min-height: 100vh;
  min-height: 100dvh;
}

.app {
  height: 100%;
  display: grid;
  grid-template-columns: 340px 1fr;
  min-height: 100vh;
  min-height: 100dvh;
}

.sidebar {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 18px 16px;
  border-right: 1px solid var(--border);
  background: linear-gradient(180deg, rgba(0, 0, 0, 0.18) 0%, rgba(0, 0, 0, 0.05) 100%);
  overflow: auto;
}

.header h1 {
  font-size: 18px;
  margin: 0 0 6px;
  letter-spacing: 0.2px;
}

.header__row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.header__row h1 {
  margin: 0;
}

.header__help {
  padding: 8px 10px;
  border-radius: 999px;
}

.tagline {
  margin: 0;
  color: var(--muted);
}

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

.panel h2 {
  margin: 0 0 10px;
  font-size: 13px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.86);
}

.hint {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 13px;
}

.panel select {
  width: 100%;
  border: 1px solid var(--border);
  background: rgba(0, 0, 0, 0.22);
  color: var(--text);
  border-radius: 10px;
  padding: 8px;
  outline: none;
}

.panel select:focus {
  border-color: rgba(120, 240, 255, 0.8);
  box-shadow: 0 0 0 2px rgba(120, 240, 255, 0.14);
}

.panel select option {
  background: #0b1020;
  color: rgba(255, 255, 255, 0.92);
}

.field {
  display: grid;
  gap: 6px;
  margin-bottom: 10px;
}

.field__label {
  font-size: 12px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.78);
}

.structures-buttons {
  margin-top: 10px;
}

.buttons {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

button {
  appearance: none;
  border: 1px solid var(--border);
  background: var(--panel2);
  color: var(--text);
  padding: 10px 10px;
  border-radius: 10px;
  cursor: pointer;
  transition: transform 0.06s ease, background 0.2s ease;
}

button:hover {
  background: rgba(255, 255, 255, 0.14);
}

button:active {
  transform: translateY(1px);
}

.toggles {
  margin-top: 10px;
  display: grid;
  gap: 8px;
}

.toggle {
  display: flex;
  gap: 10px;
  align-items: center;
  color: var(--muted);
}

.toggle input {
  width: 16px;
  height: 16px;
}

.tips {
  margin: 0;
  padding-left: 18px;
  color: var(--muted);
}

.tips-mobile {
  display: none;
}

.tips li {
  margin: 6px 0;
}

kbd {
  display: inline-block;
  padding: 1px 6px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: rgba(0, 0, 0, 0.25);
  color: rgba(255, 255, 255, 0.92);
  font-size: 12px;
}

.status {
  margin-top: auto;
  padding-top: 8px;
  border-top: 1px solid var(--border);
  color: var(--muted);
}

.stage {
  position: relative;
  overflow: hidden;
  user-select: none;
}

#canvas {
  width: 100%;
  height: 100%;
  display: block;
  cursor: default;
  touch-action: none;
}

.mobile-ui body,
.mobile-ui .stage,
.mobile-ui #canvas {
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.sidebar-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.44);
  backdrop-filter: blur(2px);
  z-index: 15;
}

.help-overlay {
  position: fixed;
  inset: 0;
  z-index: 30;
  display: grid;
  place-items: center;
  padding: 18px;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(6px);
}

.help-overlay[hidden] {
  display: none !important;
}

.help-overlay__panel {
  width: min(920px, 96vw);
  max-height: min(86vh, 860px);
  overflow: auto;
  border-radius: 16px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  background: rgba(10, 14, 28, 0.975);
  box-shadow: 0 18px 60px rgba(0, 0, 0, 0.42);
}

.help-overlay__header {
  position: sticky;
  top: 0;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 12px 14px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  background: rgba(10, 14, 28, 0.95);
  backdrop-filter: blur(8px);
}

.help-overlay__title {
  font-weight: 700;
  letter-spacing: 0.4px;
}

.help-overlay__close {
  position: relative;
  z-index: 2;
  pointer-events: auto;
  width: 44px;
  height: 44px;
  padding: 0;
  border-radius: 12px;
  line-height: 44px;
  text-align: center;
}

.help-overlay__content {
  padding: 14px 16px 18px;
  color: rgba(255, 255, 255, 0.88);
}

.help-overlay__content p {
  color: rgba(255, 255, 255, 0.84);
}

.help-overlay__content h3 {
  margin: 18px 0 8px;
  font-size: 14px;
  letter-spacing: 0.4px;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.92);
}

html:not(.mobile-ui) .help-mobile {
  display: none;
}

.mobile-ui .help-desktop {
  display: none;
}

.floating-toolbar {
  position: absolute;
  left: 12px;
  right: 12px;
  top: 12px;
  z-index: 18;
  display: none;
  gap: 8px;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-start;
  pointer-events: auto;
}

.toolbar-btn {
  padding: 10px 12px;
  border-radius: 999px;
  background: rgba(0, 0, 0, 0.28);
  border: 1px solid rgba(255, 255, 255, 0.16);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.22);
  white-space: nowrap;
}

.selection-popover {
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: calc(12px + env(safe-area-inset-bottom, 0px));
  z-index: 18;
  display: none;
  gap: 10px;
  align-items: center;
  justify-content: space-between;
  padding: 10px 12px;
  border-radius: 16px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  background: rgba(0, 0, 0, 0.28);
  backdrop-filter: blur(8px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.22);
}

.selection-popover__label {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.86);
}

.selection-popover__buttons {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.radial-menu {
  position: absolute;
  z-index: 22;
  display: none;
  width: 220px;
  height: 220px;
  transform: translate(-50%, -50%);
  pointer-events: auto;
  touch-action: none;
  --radius: 86px;
}

.radial-menu::before {
  content: '';
  position: absolute;
  inset: 14px;
  border-radius: 999px;
  background: rgba(0, 0, 0, 0.18);
  border: 1px solid rgba(255, 255, 255, 0.14);
  backdrop-filter: blur(10px);
  box-shadow: 0 12px 34px rgba(0, 0, 0, 0.3);
  pointer-events: none;
}

.radial-menu__btn,
.radial-menu__center {
  position: absolute;
  left: 50%;
  top: 50%;
  pointer-events: auto;
}

.radial-menu__btn {
  transform: translate(-50%, -50%) rotate(var(--angle)) translate(var(--radius))
    rotate(calc(-1 * var(--angle)));
}

.radial-menu__btn.is-hovered {
  border-color: rgba(120, 240, 255, 0.8);
  box-shadow: 0 0 0 2px rgba(120, 240, 255, 0.22), 0 10px 30px rgba(0, 0, 0, 0.22);
}

.radial-menu__center {
  width: 56px;
  height: 56px;
  padding: 0;
  font-size: 26px;
  line-height: 56px;
  text-align: center;
  transform: translate(-50%, -50%);
  border-radius: 999px;
  background: rgba(0, 0, 0, 0.32);
}

.radial-menu__center.is-hovered {
  border-color: rgba(120, 240, 255, 0.8);
  box-shadow: 0 0 0 2px rgba(120, 240, 255, 0.22), 0 10px 30px rgba(0, 0, 0, 0.22);
}

.mobile-ui .selection-popover:not([hidden]) {
  display: flex;
}

.mobile-ui .radial-menu:not([hidden]) {
  display: block;
}

#menuBtn {
  display: none;
}

.toolbar-btn[aria-pressed='true'] {
  border-color: rgba(120, 240, 255, 0.7);
  box-shadow: 0 0 0 2px rgba(120, 240, 255, 0.18), 0 10px 30px rgba(0, 0, 0, 0.22);
}

.structure-list {
  display: none;
  margin-top: 10px;
  border: 1px solid var(--border);
  background: rgba(0, 0, 0, 0.18);
  border-radius: 12px;
  overflow: auto;
  max-height: 260px;
  padding: 6px;
}

.structure-item {
  width: 100%;
  text-align: left;
  margin: 0;
  border-radius: 10px;
  padding: 10px 10px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  background: rgba(255, 255, 255, 0.06);
}

.structure-item + .structure-item {
  margin-top: 6px;
}

.structure-item.is-selected {
  border-color: rgba(120, 240, 255, 0.65);
  background: rgba(120, 240, 255, 0.14);
}

.structure-header {
  margin: 8px 8px 6px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 12px;
  letter-spacing: 0.4px;
  text-transform: uppercase;
}

@media (max-width: 920px) {
  .mobile-ui .app {
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr;
  }
  .mobile-ui .sidebar {
    border-right: none;
    border-bottom: 1px solid var(--border);
    grid-row: 1;
  }
  .mobile-ui .stage {
    grid-row: 2;
    min-height: 0;
  }
}

.mobile-ui .floating-toolbar {
  display: flex;
}

.mobile-ui .header__help {
  display: none;
}

.mobile-ui button {
  padding: 12px 12px;
}

.mobile-ui .panel-controls {
  display: none;
}

.mobile-ui .tips-desktop {
  display: none;
}

.mobile-ui .tips-mobile {
  display: block;
}

.mobile-ui .toggle input {
  width: 20px;
  height: 20px;
}

/* Multi-select <select> is awkward on iOS; use the touch list. */
.mobile-ui #structureSelect {
  display: none;
}

.mobile-ui .field {
  display: none;
}

.mobile-ui .structure-list {
  display: block;
}

@media (max-width: 860px) {
  .mobile-ui .app {
    grid-template-columns: 1fr;
  }

  .mobile-ui .sidebar {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    width: min(360px, 92vw);
    max-width: 92vw;
    z-index: 40;
    transform: translateX(-110%);
    transition: transform 0.18s ease;
    border-right: 1px solid var(--border);
    border-bottom: none;
  }

  .mobile-ui .sidebar.open {
    transform: translateX(0);
  }

  .mobile-ui #menuBtn {
    display: inline-flex;
  }
}