/* Energy Machine Workshop */

:root {
  --accent:       #004445;
  --accent-light: #006668;
  --focus-glow:   #FFD166;
  --ink:          #2C3E3E;
  --muted:        #5A6E6E;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  height: 100%;
  overflow: hidden;
  background: #F5F1E5;
  font-family: Roboto, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

#sim-app {
  display: flex;
  flex-direction: column;
  height: 100%;
}

#stage-panel {
  flex: 1;
  position: relative;
  overflow: hidden;
}

#sim-canvas {
  width: 100%;
  height: 100%;
  display: block;
}

#sim-canvas:focus-visible {
  outline: 2px solid #60a5fa;
  outline-offset: -2px;
}

/* Keyboard-accessibility layer: transparent proxy buttons over each canvas
   object. pointer-events stay off so the mouse passes straight through to the
   canvas; the focused object's highlight is drawn on the canvas (drawKbFocus). */
#kb-layer {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 5;
}
#kb-layer .kb-proxy {
  position: absolute;
  margin: 0;
  padding: 0;
  border: 0;
  background: transparent;
  pointer-events: none;
  outline: none;       /* the visible indicator is the canvas-drawn ring */
  color: transparent;
}

/* ── Accessibility ── */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ── Info dialog ──
   Color contract: header = var(--accent) with white text. Tabs/footer = #F8FBFB.
   Body text = var(--ink). H3s = var(--accent). */
#info-dialog {
  border: none;
  border-radius: 12px;
  padding: 0;
  width: min(560px, calc(100vw - 32px));
  max-height: calc(100vh - 80px);
  overflow: hidden;
  margin: auto;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.22);
  background: #ffffff;
}

#info-dialog::backdrop {
  background: rgba(0, 0, 0, 0.45);
}

.dialog-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 16px;
  background: var(--accent);
  color: #ffffff;
}

.dialog-header h2 {
  font-size: 16px;
  font-weight: 600;
}

#dialog-close-btn {
  background: transparent;
  border: none;
  color: #ffffff;
  font-size: 18px;
  cursor: pointer;
  width: 32px;
  height: 32px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

#dialog-close-btn:hover {
  background: rgba(255, 255, 255, 0.15);
}

#dialog-close-btn:focus-visible {
  outline: 3px solid var(--focus-glow);
  outline-offset: 2px;
}

.dialog-tabs {
  display: flex;
  border-bottom: 2px solid #E5EAE9;
  background: #F8FBFB;
}

.tab-btn {
  flex: 1;
  background: none;
  border: none;
  border-bottom: 3px solid transparent;
  margin-bottom: -2px;
  padding: 10px 0;
  font-family: Roboto, Arial, sans-serif;
  font-size: 14px;
  font-weight: 600;
  color: var(--muted);
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s;
}

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

.tab-btn.active,
.tab-btn[aria-selected="true"] {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.tab-btn:focus-visible {
  outline: 3px solid var(--focus-glow);
  outline-offset: -3px;
}

.dialog-body {
  padding: 16px 20px;
  overflow-y: auto;
  max-height: calc(100vh - 240px);
  color: var(--ink);
  font-size: 14px;
  line-height: 1.55;
}

.dialog-body h3 {
  font-size: 14px;
  font-weight: 600;
  color: var(--accent);
  margin-top: 14px;
  margin-bottom: 6px;
}

.dialog-body h3:first-child {
  margin-top: 0;
}

/* Sub-headings inside a panel. INFO-1 fixes the h3 set for the For Teachers tab
   (Standards / Design intent / Discussion prompts); the longer design-intent
   sections here sit UNDER that heading rather than beside it, so they are h4s.
   Content typography only, no dialog chrome. */
.dialog-body h4 {
  font-size: 13px;
  font-weight: 600;
  color: var(--ink);
  margin-top: 12px;
  margin-bottom: 4px;
}

.dialog-body p {
  margin-bottom: 8px;
}

.dialog-body ul,
.dialog-body ol {
  padding-left: 20px;
  margin-bottom: 8px;
}

.dialog-body li {
  margin-bottom: 4px;
}

.dialog-body .standard-tag {
  display: inline-block;
  background: #E8F5F5;
  color: var(--accent);
  font-weight: 700;
  font-size: 12px;
  padding: 2px 8px;
  border-radius: 4px;
  margin-right: 6px;
}

.dialog-body details {
  margin: 8px 0 10px;
  border: 1px solid #E5EAE9;
  border-radius: 6px;
  padding: 6px 12px;
}

.dialog-body summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--accent);
}

.dialog-body details[open] summary {
  margin-bottom: 6px;
}

.dialog-footer {
  display: flex;
  justify-content: flex-end;
  padding: 12px 20px;
  border-top: 1px solid #E5EAE9;
  background: #F8FBFB;
}

.dialog-close-footer {
  background: var(--accent);
  color: #ffffff;
  border: none;
  border-radius: 6px;
  padding: 8px 20px;
  font-family: Roboto, Arial, sans-serif;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s;
}

.dialog-close-footer:hover {
  background: var(--accent-light);
}

.dialog-close-footer:focus-visible {
  outline: 3px solid var(--focus-glow);
  outline-offset: 2px;
}