/* ============================================================
   LAYOUT — positioning & structure
   How the major UI regions sit on screen.
   ============================================================ */

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

html, body {
  height: 100%;
  overflow: hidden;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", sans-serif;
  font-size: 13px;
  line-height: 1.4;
  color: var(--text-primary);
  background: var(--bg-canvas);
  transition: background-color 0.25s ease;
}

/* ---- 3D canvas ---- */
#canvas-container {
  position: fixed;
  top: var(--topbar-h); left: 0;
  width: 100%;
  height: calc(100% - var(--topbar-h));
  z-index: 1;
}

/* Cursor styles per active tool */
body[data-tool="pan"]      #canvas-container { cursor: grab; }
body[data-tool="pan"].dragging #canvas-container { cursor: grabbing; }
body[data-tool="distance"] #canvas-container,
body[data-tool="polyline"] #canvas-container,
body[data-tool="area"]     #canvas-container,
body[data-tool="angle"]    #canvas-container,
body[data-tool="incline"]  #canvas-container,
body[data-tool="point"]    #canvas-container,
body[data-tool="copy"]     #canvas-container,
body[data-tool="knowndim"] #canvas-container { cursor: crosshair; }
body[data-tool="edit"]     #canvas-container,
body[data-tool="delete"]   #canvas-container { cursor: default; }
body[data-tool="edit"].dragging #canvas-container { cursor: grabbing; }

/* ---- Top bar (two-row navigation, docked) ---- */
:root { --topbar-h: 79px; }
#topbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--topbar-h);
  z-index: 10;
  display: flex;
  flex-direction: column;
  align-items: stretch;
  justify-content: center;
  gap: 6px;
  padding: 6px 16px;
  border: none;
  border-bottom: 1px solid var(--topbar-border);
  border-radius: 0;
  box-shadow: var(--shadow-soft);
  background-color: var(--topbar-bg);
}
.topbar-row { display: flex; align-items: center; gap: 6px; }
.topbar-spacer { flex: 1; }
.topbar-divider { height: 1px; background: var(--topbar-border); margin: 0 -8px; }

/* ---- Left toolbar ---- */
#toolbar {
  position: fixed;
  left: 12px;
  top: calc(var(--topbar-h) + (100% - var(--topbar-h)) / 2);
  transform: translateY(-50%);
  z-index: 10;
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 6px;
  background: var(--topbar-bg);
  border: 1px solid var(--topbar-border);
  border-radius: 10px;
  box-shadow: var(--shadow);
}

.tool-divider {
  height: 1px;
  margin: 4px 6px;
  background: var(--topbar-border);
}

/* ---- Bottom secondary toolbar ---- */
#statusbar {
  position: fixed;
  bottom: 12px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 4px 6px;
  background: var(--topbar-bg);
  border: 1px solid var(--topbar-border);
  border-radius: 8px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(12px);
  background-color: color-mix(in srgb, var(--topbar-bg) 92%, transparent);
  max-width: 80vw;
  transition: opacity 0.2s, transform 0.2s;
}

.status-divider {
  width: 1px;
  height: 14px;
  background: var(--border-subtle);
}

#right-panel {
  position: fixed;
  right: 0;
  top: var(--topbar-h);
  bottom: 0;
  width: 300px;
  z-index: 10;
  background: var(--bg-panel);
  border-left: 1px solid var(--border-subtle);
  box-shadow: var(--shadow);
  transform: translateX(100%);
  transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
}

body.panel-open #right-panel {
  transform: translateX(0);
}

.panel-header {
  padding: 16px 18px 12px;
  border-bottom: 1px solid var(--border-subtle);
}

/* Measurements body */
.panel-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;               /* the list scrolls, not the whole body */
  padding: 16px 18px 0;           /* bottom padding moves to the scroller */
  min-height: 0;                  /* allows nested overflow to work in flex */
}

/* ---- Loading overlay ---- */
#loading {
  position: fixed;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  z-index: 100;
  padding: 14px 22px;
  background: var(--bg-panel);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 13px;
  box-shadow: var(--shadow);
  display: none;
  align-items: center;
  gap: 10px;
}

#loading.visible { display: flex; }

/* ---- Mobile responsive ---- */
@media (max-width: 600px) {
  #toolbar {
    flex-direction: row;
    left: 50%;
    top: auto;
    bottom: 60px;
    transform: translateX(-50%);
  }
  #statusbar {
    bottom: 12px;
    width: auto;
  }
  #right-panel { width: 100%; }
  body.panel-open #panel-toggle { right: calc(100% - 32px); }
}