* { box-sizing: border-box; }

:root {
  --bg: #050510;
  --bg-overlay: rgba(0,0,0,0.9);
  --bg-overlay-top: rgba(0,0,0,0.6);
  --text: #fff;
  --text-muted: rgba(255,255,255,0.8);
  --text-dim: rgba(255,255,255,0.6);
  --panel-bg: rgba(0,0,0,0.7);
  --panel-border: rgba(255,255,255,0.1);
  --input-bg: rgba(255,255,255,0.1);
  --input-border: rgba(255,255,255,0.2);
  --slider-track: rgba(255,255,255,0.2);
  --accent: #129079;
  --accent-hover: #0f7a6a;
  --observe-active: #E91E63;
  --theme-btn-bg: rgba(255,255,255,0.1);
}

[data-theme="light"] {
  --bg: #e8edf5;
  --bg-overlay: rgba(255,255,255,0.85);
  --bg-overlay-top: rgba(255,255,255,0.7);
  --text: #1a1a2e;
  --text-muted: #2d2d44;
  --text-dim: #4a4a6a;
  --panel-bg: rgba(255,255,255,0.9);
  --panel-border: rgba(0,0,0,0.08);
  --input-bg: rgba(255,255,255,0.9);
  --input-border: rgba(0,0,0,0.15);
  --slider-track: rgba(0,0,0,0.15);
  --accent: #0d6b5c;
  --accent-hover: #0a5549;
  --observe-active: #c41a52;
  --theme-btn-bg: rgba(0,0,0,0.06);
}

body {
  margin: 0;
  font-family: 'DM Sans', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  overflow: hidden;
}

.demo-layout {
  position: relative;
  width: 100vw;
  height: 100vh;
}

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

.demo-ui {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 24px 32px 32px;
  background: linear-gradient(0deg, var(--bg-overlay) 0%, rgba(0,0,0,0.5) 60%, transparent);
  pointer-events: none;
}
[data-theme="light"] .demo-ui {
  background: linear-gradient(0deg, var(--bg-overlay) 0%, rgba(255,255,255,0.4) 60%, transparent);
}
.demo-ui > * { pointer-events: auto; }

.demo-header {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  padding: 20px 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: linear-gradient(180deg, var(--bg-overlay-top) 0%, transparent);
}
[data-theme="light"] .demo-header {
  background: linear-gradient(180deg, var(--bg-overlay-top) 0%, transparent);
}
.demo-header .logo { font-size: clamp(16px, 3.2vw, 22px); font-weight: 600; color: var(--text); text-decoration: none; line-height: 1.2; }
.header-right { display: flex; align-items: center; gap: 16px; }
.demo-header .back { font-size: 14px; color: var(--text-muted); text-decoration: none; }
.demo-header .back:hover { color: var(--text); }

.theme-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid var(--panel-border);
  border-radius: 8px;
  background: var(--theme-btn-bg);
  color: var(--text);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s, border-color 0.2s;
}
.theme-btn:hover {
  background: var(--input-bg);
}
.theme-icon { font-size: 18px; }

/* Toolbar cluster: desktop uses display:contents so children keep original layout */
.demo-toolbar-cluster {
  display: contents;
}

.params-toggle-mobile {
  display: none;
  align-items: center;
  justify-content: flex-start;
  gap: 10px;
  width: 100%;
  min-height: 44px;
  padding: 10px 16px;
  border: 1px solid var(--panel-border);
  border-radius: 12px;
  background: var(--panel-bg);
  color: var(--text);
  font-family: inherit;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  box-shadow: 0 2px 12px rgba(0,0,0,0.12);
}
.params-toggle-mobile:hover {
  background: var(--input-bg);
}
.params-toggle-chevron {
  display: inline-block;
  margin-left: auto;
  transition: transform 0.2s ease;
  font-size: 12px;
  opacity: 0.7;
}
.demo-toolbar-cluster.params-panel-open .params-toggle-chevron {
  transform: rotate(180deg);
}

/* Interpretation toolbar — desktop: pills + actions; narrow: dropdown + actions */
.interpretation-tabs {
  position: absolute;
  top: 72px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 100;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 8px;
  max-width: calc(100vw - 24px);
  padding: 6px 12px;
  background: var(--panel-bg);
  border-radius: 999px;
  border: 1px solid var(--panel-border);
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}
.interp-mobile-label {
  display: none;
  width: 100%;
  margin: 0;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-dim);
}
.interp-select-mobile {
  display: none;
  width: 100%;
  box-sizing: border-box;
  min-height: 44px;
  padding: 10px 14px;
  font-family: inherit;
  font-size: 16px;
  font-weight: 500;
  color: var(--text);
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  border-radius: 10px;
  cursor: pointer;
  -webkit-appearance: none;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23999' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
}
[data-theme="light"] .interp-select-mobile {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23444' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
}
.interp-tabs-pills {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 4px;
}
.interp-toolbar-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 6px;
}
.interp-tab {
  padding: 8px 14px;
  border: none;
  border-radius: 999px;
  background: transparent;
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  min-height: 36px;
}
.interp-tab:hover { color: var(--text); background: var(--theme-btn-bg); }
.interp-tab.active {
  background: var(--interp-accent, var(--accent));
  color: #fff;
}
.info-toggle {
  width: 44px;
  height: 44px;
  border: none;
  border-radius: 50%;
  background: var(--theme-btn-bg);
  color: var(--text);
  font-size: 18px;
  cursor: pointer;
  flex-shrink: 0;
}
.info-toggle:hover { background: var(--input-bg); }

.tour-btn {
  padding: 10px 14px;
  min-height: 44px;
  border: none;
  border-radius: 999px;
  background: var(--theme-btn-bg);
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
}
.tour-btn:hover { color: var(--text); background: var(--input-bg); }

@media (max-width: 768px) {
  .demo-toolbar-cluster {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 58px;
    left: 12px;
    right: 12px;
    z-index: 100;
    gap: 10px;
    align-items: stretch;
    pointer-events: none;
  }
  .demo-toolbar-cluster > * {
    pointer-events: auto;
  }

  .interpretation-tabs {
    position: static;
    transform: none;
    left: auto;
    width: 100%;
    max-width: none;
    border-radius: 14px;
    padding: 10px 12px;
    justify-content: stretch;
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
  }
  .interp-mobile-label { display: block; }
  .interp-select-mobile { display: block; }
  .interp-tabs-pills { display: none; }
  .interp-toolbar-actions {
    justify-content: space-between;
    gap: 8px;
    flex-wrap: nowrap;
  }
  .demo-header {
    padding: 12px 16px;
    flex-wrap: wrap;
    gap: 8px;
  }
  .demo-header .logo { font-size: clamp(14px, 4vw, 18px); }
  .header-right {
    flex-wrap: wrap;
    gap: 8px;
  }
  .demo-header .back {
    font-size: 13px;
  }

  .params-toggle-mobile {
    display: flex;
    order: 2;
  }

  .params-panel {
    order: 3;
    position: static;
    display: none;
    width: 100%;
    max-height: min(52vh, 360px);
    overflow-y: auto;
    margin: 0;
    box-shadow: 0 4px 20px rgba(0,0,0,0.18);
  }
  .demo-toolbar-cluster.params-panel-open .params-panel {
    display: block;
  }

  .tour-overlay {
    left: 12px;
    right: 12px;
    transform: none;
    max-width: none;
    bottom: 100px;
  }
}

@media (min-width: 769px) and (max-width: 1100px) {
  .interpretation-tabs {
    border-radius: 16px;
    padding: 8px 10px;
  }
  .interp-tab {
    padding: 7px 11px;
    font-size: 12px;
    min-height: 34px;
  }
  .tour-btn {
    padding: 8px 11px;
    min-height: 38px;
    font-size: 12px;
  }
  .info-toggle {
    width: 38px;
    height: 38px;
  }
}

.tour-overlay {
  position: absolute;
  bottom: 120px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 180;
  max-width: 520px;
  display: none;
}
.tour-overlay.open { display: block; }
.tour-dialog {
  padding: 20px 24px;
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 12px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.4);
}
.tour-text {
  font-size: 16px;
  line-height: 1.6;
  margin-bottom: 16px;
  color: var(--text);
}
.tour-actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.tour-skip {
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 14px;
  cursor: pointer;
}
.tour-skip:hover { color: var(--text); }
.tour-next {
  padding: 10px 24px;
  background: var(--accent);
  border: none;
  border-radius: 8px;
  color: #fff;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
}
.tour-next:hover { background: var(--accent-hover); }
.tour-progress {
  margin-top: 12px;
  font-size: 12px;
  color: var(--text-dim);
}

/* Info panel */
.info-panel {
  position: absolute;
  top: 0;
  right: 0;
  width: 360px;
  max-width: 100%;
  height: 100%;
  background: var(--panel-bg);
  border-left: 1px solid var(--panel-border);
  box-shadow: -8px 0 24px rgba(0,0,0,0.2);
  z-index: 200;
  transform: translateX(100%);
  transition: transform 0.3s ease;
  overflow-y: auto;
}
.info-panel.open { transform: translateX(0); }
.info-close {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 36px;
  height: 36px;
  border: none;
  border-radius: 50%;
  background: var(--theme-btn-bg);
  color: var(--text);
  font-size: 24px;
  line-height: 1;
  cursor: pointer;
}
.info-close:hover { background: var(--input-bg); }
.info-content {
  padding: 24px 24px 24px 20px;
  padding-top: 60px;
}
.info-content h3 { margin: 0 0 8px 0; font-size: 20px; }
.info-content .meta { font-size: 13px; color: var(--text-dim); margin-bottom: 16px; }
.info-content .happening { font-size: 13px; color: var(--text-muted); margin-bottom: 12px; font-style: italic; }
.info-content .story { font-size: 15px; line-height: 1.6; margin-bottom: 20px; }
.info-content .section { margin-bottom: 20px; }
.info-content .section-title { font-size: 12px; text-transform: uppercase; letter-spacing: 1px; margin-bottom: 8px; color: var(--text-dim); }
.info-content .strengths li::before { content: '✓'; color: #66BB6A; margin-right: 8px; }
.info-content .weaknesses li::before { content: '?'; color: #EF5350; margin-right: 8px; }
.info-content ul { margin: 0; padding-left: 20px; }
.info-content li { margin-bottom: 6px; }
.info-content .quote { font-style: italic; padding: 12px; background: var(--theme-btn-bg); border-radius: 8px; margin: 16px 0; font-size: 14px; }
.info-content .support { font-size: 14px; font-weight: 600; }

.timeline-row {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 16px;
}
.timeline-row label { font-size: 14px; min-width: 80px; color: var(--text); }
.timeline-slider {
  flex: 1;
  height: 8px;
  -webkit-appearance: none;
  background: var(--slider-track);
  border-radius: 4px;
}
.timeline-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 20px; height: 20px;
  background: var(--accent);
  border-radius: 50%;
  cursor: pointer;
}
.timeline-slider::-moz-range-thumb {
  width: 20px; height: 20px;
  background: var(--accent);
  border-radius: 50%;
  cursor: pointer;
  border: none;
}
.play-btn {
  width: 44px; height: 44px;
  border: 2px solid var(--panel-border);
  border-radius: 50%;
  background: transparent;
  color: var(--text);
  cursor: pointer;
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.play-btn:hover { background: var(--theme-btn-bg); }
.particle-count { font-size: 14px; color: var(--text-muted); }

.controls-row {
  display: flex;
  gap: 24px;
  align-items: center;
  flex-wrap: wrap;
}
.controls-row p { color: var(--text-dim); }
.observe-btn {
  padding: 12px 24px;
  border: 2px solid var(--panel-border);
  border-radius: 8px;
  background: transparent;
  color: var(--text);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
}
.observe-btn.active { background: var(--observe-active); border-color: var(--observe-active); color: #fff; }
.observe-btn:hover { background: var(--theme-btn-bg); }
.observe-btn.active:hover { background: var(--observe-active); opacity: 0.95; }
.reset-btn { border-color: var(--accent) !important; }

.params-panel {
  position: absolute;
  top: 130px;
  right: 24px;
  width: 220px;
  padding: 20px;
  background: var(--panel-bg);
  border-radius: 12px;
  border: 1px solid var(--panel-border);
}
@media (min-width: 769px) {
  .params-toggle-mobile {
    display: none !important;
  }
}
.params-panel h4 { margin: 0 0 16px 0; font-size: 14px; text-transform: uppercase; letter-spacing: 1px; color: var(--text); }
.param-row { margin-bottom: 12px; }
.param-row label { display: block; font-size: 12px; margin-bottom: 4px; color: var(--text-muted); }
.param-row input {
  width: 100%;
  padding: 6px 10px;
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  border-radius: 4px;
  color: var(--text);
}
.recompute-btn {
  margin-top: 16px;
  width: 100%;
  padding: 10px;
  background: var(--accent);
  border: none;
  border-radius: 6px;
  color: #fff;
  font-weight: 600;
  cursor: pointer;
}
.recompute-btn:hover { background: var(--accent-hover); }

.status-badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 600;
  background: var(--input-bg);
  border: 1px solid var(--panel-border);
  color: var(--text-muted);
}
.interpretation-tabs-many {
  max-width: min(96vw, 920px);
}
.interpretation-tabs-many .interp-tabs-pills {
  justify-content: flex-start;
  padding-right: 4px;
}

/* Advanced lab: single-row interpretation bar on large desktop */
@media (min-width: 1025px) {
  .demo-layout-advanced .interpretation-tabs-many {
    max-width: min(99vw, 1720px);
    flex-wrap: nowrap;
    padding: 4px 8px 4px 10px;
    gap: 6px;
    border-radius: 999px;
  }
  .demo-layout-advanced .interpretation-tabs-many .interp-tabs-pills {
    display: flex;
    flex-wrap: nowrap;
    align-items: center;
    max-height: none;
    overflow-x: auto;
    overflow-y: hidden;
    flex: 1 1 auto;
    min-width: 0;
    gap: 3px;
    padding: 2px 4px 2px 0;
    scrollbar-width: thin;
  }
  .demo-layout-advanced .interpretation-tabs-many .interp-tabs-pills::-webkit-scrollbar {
    height: 5px;
  }
  .demo-layout-advanced .interpretation-tabs-many .interp-tabs-pills::-webkit-scrollbar-thumb {
    border-radius: 99px;
    background: var(--slider-track);
  }
  .demo-layout-advanced .interpretation-tabs-many .interp-tab {
    padding: 5px 9px;
    font-size: 11px;
    font-weight: 600;
    min-height: 30px;
    flex-shrink: 0;
    white-space: nowrap;
    letter-spacing: -0.015em;
  }
  .demo-layout-advanced .interpretation-tabs-many .interp-toolbar-actions {
    flex-shrink: 0;
  }
  .demo-layout-advanced .interpretation-tabs-many .info-toggle {
    width: 36px;
    height: 36px;
    font-size: 16px;
  }
}

/* Advanced lab: tablet — same interpretation UI as mobile (dropdown) when pills are too wide */
@media (min-width: 769px) and (max-width: 1024px) {
  .demo-layout-advanced .demo-toolbar-cluster {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 58px;
    left: 12px;
    right: 12px;
    z-index: 100;
    gap: 10px;
    align-items: stretch;
    pointer-events: none;
  }
  .demo-layout-advanced .demo-toolbar-cluster > * {
    pointer-events: auto;
  }
  .demo-layout-advanced .interpretation-tabs-many {
    position: static;
    transform: none;
    left: auto;
    width: 100%;
    max-width: none;
    border-radius: 14px;
    flex-direction: column;
    align-items: stretch;
    flex-wrap: nowrap;
    padding: 10px 12px;
  }
  .demo-layout-advanced .interpretation-tabs-many .interp-mobile-label {
    display: block;
  }
  .demo-layout-advanced .interpretation-tabs .interp-select-mobile {
    display: block;
  }
  .demo-layout-advanced .interpretation-tabs-many .interp-tabs-pills {
    display: none;
  }
  .demo-layout-advanced .interpretation-tabs-many .interp-toolbar-actions {
    justify-content: flex-end;
    flex-wrap: nowrap;
    gap: 8px;
  }
  .demo-layout-advanced .params-toggle-mobile {
    display: flex !important;
    order: 2;
  }
  .demo-layout-advanced .params-panel {
    order: 3;
    position: static;
    display: none;
    width: 100%;
    max-height: min(52vh, 400px);
    overflow-y: auto;
    margin: 0;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.18);
  }
  .demo-layout-advanced .params-panel-advanced {
    width: 100%;
  }
  .demo-layout-advanced .demo-toolbar-cluster.params-panel-open .params-panel {
    display: block;
  }
}

.params-panel-advanced {
  width: 280px;
}
.param-readout {
  display: block;
  font-size: 11px;
  margin-top: 6px;
  color: var(--text-dim);
  word-break: break-word;
}
.param-fieldset {
  border: 1px solid var(--panel-border);
  border-radius: 8px;
  padding: 10px 12px;
  margin: 12px 0;
}
.param-fieldset legend {
  font-size: 12px;
  color: var(--text-muted);
  padding: 0 6px;
}
.radio-label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-right: 10px;
  margin-bottom: 6px;
  font-size: 13px;
  cursor: pointer;
}
.observe-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}
.demo-mode-link {
  font-weight: 600;
  color: var(--accent);
}

/* “How it works” quick reference (Features-aligned) */
.help-features-btn {
  padding: 8px 14px;
  min-height: 44px;
  border: 1px solid var(--panel-border);
  border-radius: 8px;
  background: var(--theme-btn-bg);
  color: var(--text);
  font-family: inherit;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s, border-color 0.2s;
}
.help-features-btn:hover {
  background: var(--input-bg);
}
.help-features-btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

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

.demo-modal-overlay:not([hidden]) {
  display: flex;
  align-items: center;
  justify-content: center;
  position: fixed;
  inset: 0;
  z-index: 500;
  padding: 20px;
  background: rgba(0, 0, 0, 0.55);
  -webkit-backdrop-filter: blur(4px);
  backdrop-filter: blur(4px);
}

[data-theme="light"] .demo-modal-overlay:not([hidden]) {
  background: rgba(30, 36, 52, 0.28);
}

.demo-modal-dialog {
  position: relative;
  width: 100%;
  max-width: 480px;
  max-height: min(85vh, 640px);
  overflow-y: auto;
  padding: 24px 24px 20px;
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 14px;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.45);
}

.demo-modal-close {
  position: absolute;
  top: 12px;
  right: 12px;
  width: 44px;
  height: 44px;
  border: none;
  border-radius: 50%;
  background: var(--theme-btn-bg);
  color: var(--text);
  font-size: 26px;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}
.demo-modal-close:hover {
  background: var(--input-bg);
}
.demo-modal-close:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.demo-modal-title {
  margin: 0 48px 12px 0;
  font-size: 22px;
  font-weight: 600;
  line-height: 1.25;
  color: var(--text);
}

.demo-modal-lead {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.5;
  color: var(--text-muted);
}

.demo-modal-list {
  margin: 0;
  padding-left: 1.2em;
  font-size: 14px;
  line-height: 1.55;
  color: var(--text);
}

.demo-modal-list li + li {
  margin-top: 12px;
}

.demo-modal-note {
  margin: 16px 0 0;
  padding: 12px 14px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--text-muted);
  background: var(--input-bg);
  border-radius: 8px;
  border: 1px solid var(--panel-border);
}

@media (max-width: 768px) {
  .help-features-btn {
    font-size: 13px;
    padding: 8px 10px;
  }
}