/* ============================================================================
 * App shell layout — CSS grid
 * ==========================================================================*/
#app {
  display: grid;
  grid-template-columns: auto 1fr auto;
  grid-template-rows: 34px 54px auto 1fr 28px;
  grid-template-areas:
    "menu menu menu"
    "tool tool tool"
    "subtool subtool subtool"
    "left center right"
    "status status status";
  height: 100vh;
  overflow: hidden;
}

/* ---- Menu bar ---- */
#menubar {
  grid-area: menu;
  display: flex; align-items: center; gap: var(--sp-1);
  padding: 0 var(--sp-3);
  background: var(--surface-0);
  border-bottom: 1px solid var(--border);
  font-size: var(--fs-sm);
  user-select: none;
}
.wordmark {
  display: flex; align-items: center; gap: 8px;
  font-weight: var(--fw-bold); font-size: var(--fs-md); letter-spacing: -0.01em; color: var(--text);
  padding-right: var(--sp-3); margin-right: var(--sp-1);
}
.wordmark svg { display: block; }
.menu-item {
  background: none; border: none; color: var(--text);
  padding: 5px 10px; border-radius: var(--r-sm); cursor: pointer; font-size: var(--fs-sm);
}
.menu-item:hover { background: var(--surface-hover); }
.menu-spacer { flex: 1; }
.doc-name { color: var(--text-muted); font-size: var(--fs-xs); max-width: 280px;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap; padding-right: var(--sp-2); }
.icon-btn {
  display: inline-flex; align-items: center; justify-content: center;
  width: 30px; height: 30px; border: none; background: none; color: var(--text-muted);
  border-radius: var(--r-sm); cursor: pointer;
}
.icon-btn:hover { background: var(--surface-hover); color: var(--text); }

/* ---- Main toolbar ---- */
#toolbar {
  grid-area: tool;
  display: flex; align-items: center; gap: var(--sp-1);
  padding: 0 var(--sp-3);
  background: var(--surface-0);
  border-bottom: 1px solid var(--border);
  overflow-x: auto; overflow-y: hidden;
  user-select: none;
}
#toolbar::-webkit-scrollbar { height: 0; }
.tgroup { display: flex; align-items: center; gap: 2px; flex: none; }
.sep { width: 1px; align-self: stretch; margin: 10px var(--sp-2); background: var(--border); flex: none; }
.tspacer { flex: 1; }

/* ---- Contextual sub-toolbar ---- */
#contextbar {
  grid-area: subtool;
  display: flex; align-items: center; gap: var(--sp-3);
  padding: 0 var(--sp-4);
  height: 44px;
  background: var(--surface-1);
  border-bottom: 1px solid var(--border);
  overflow: hidden; overflow-x: auto;
  transition: height var(--t-base), opacity var(--t-base);
  user-select: none;
}
#contextbar.empty { height: 0; opacity: 0; border-bottom-color: transparent; }
.ctx-label { font-size: var(--fs-sm); color: var(--text); font-weight: var(--fw-semibold);
  margin-right: var(--sp-1); flex: none; }
.ctx-hint { font-size: var(--fs-xs); color: var(--text-faint); flex: none; margin-right: var(--sp-2); }

/* ---- Left panel ---- */
#left {
  grid-area: left;
  width: 264px;
  background: var(--surface-0);
  border-right: 1px solid var(--border);
  display: flex; flex-direction: column;
  overflow: hidden; position: relative;
  transition: width var(--t-base);
}
#left.resizing, #right.resizing { transition: none; }
#left.collapsed { width: 0; border-right: none; }
.panel-body { flex: 1; overflow-y: auto; }

/* ---- Center document area ---- */
#center { grid-area: center; position: relative; overflow: hidden; background: var(--canvas); }
#viewport { position: absolute; inset: 0; overflow: auto; scroll-behavior: smooth; }
#pageList {
  display: flex; flex-direction: column; align-items: center; gap: var(--sp-8);
  padding: var(--sp-10) var(--sp-6);
  min-height: 100%;
}

/* ---- Right panel ---- */
#right {
  grid-area: right;
  width: 288px;
  background: var(--surface-0);
  border-left: 1px solid var(--border);
  display: flex; flex-direction: column;
  overflow: hidden; position: relative;
  transition: width var(--t-base);
}
#right.collapsed { width: 0; border-left: none; }

/* ---- Status bar ---- */
#statusbar {
  grid-area: status;
  display: flex; align-items: center; gap: var(--sp-4);
  padding: 0 var(--sp-4);
  background: var(--surface-0);
  border-top: 1px solid var(--border);
  font-size: var(--fs-xs); color: var(--text-muted);
  user-select: none;
}
#statusbar .sb-spacer { flex: 1; }
.saved-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--success); flex: none; }
.saved-dot.unsaved { background: var(--warning); }

/* ---- Page hosts (continuous scroll) ---- */
.page-host {
  position: relative;
  background: var(--surface-0);
  box-shadow: var(--shadow-page);
  outline: 1px solid var(--page-edge);
  flex: none;
}
.page-host .raster-layer { position: absolute; top: 0; left: 0; display: block; }
.page-host .text-layer {
  position: absolute; top: 0; left: 0; overflow: hidden; opacity: 1; line-height: 1;
  z-index: 2;
}
.page-host .text-layer > span {
  position: absolute; color: transparent; white-space: pre; cursor: text;
  transform-origin: 0 0;
}
.page-host .text-layer ::selection { background: rgba(37, 99, 235, .35); }
.page-host .canvas-container { position: absolute !important; top: 0; left: 0; z-index: 3; }
.page-host .form-layer { position: absolute; top: 0; left: 0; transform-origin: 0 0; z-index: 5; pointer-events: none; }
.page-host .form-layer .ff {
  position: absolute; box-sizing: border-box; pointer-events: none; margin: 0;
  background: rgba(37, 99, 235, 0.07); border: 1px solid rgba(37, 99, 235, 0.55);
  border-radius: 2px; font-family: var(--font-sans); color: #111; outline: none; resize: none;
}
.page-host .form-layer input.ff[type="text"], .page-host .form-layer textarea.ff { padding: 0 4px; }
.page-host .form-layer .ff-check { accent-color: var(--accent); }
.page-host.forms-active .form-layer .ff { pointer-events: auto; }
.page-host.forms-active .form-layer .ff:focus { background: rgba(37, 99, 235, 0.12); border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent-ring); }
.page-host .static-overlay { position: absolute; top: 0; left: 0; z-index: 3; pointer-events: none; }
.page-host.markup-active .text-layer { z-index: 4; }
.page-host.markup-active .canvas-container { pointer-events: none; }
.page-caption {
  position: absolute; bottom: -22px; left: 0; right: 0; text-align: center;
  font-size: var(--fs-2xs); color: var(--text-faint); user-select: none;
}
.page-skeleton {
  position: absolute; inset: 0; background: var(--surface-1);
  overflow: hidden;
}
.page-skeleton::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(100deg, transparent 20%, var(--surface-2) 50%, transparent 80%);
  transform: translateX(-100%); animation: shimmer 1.3s infinite;
}
@keyframes shimmer { to { transform: translateX(100%); } }

/* ---- Floating page indicator ---- */
#pageIndicator {
  position: absolute; top: var(--sp-3); left: 50%; transform: translateX(-50%);
  background: rgba(20, 22, 28, .82); color: #fff; padding: 4px 12px; border-radius: var(--r-full);
  font-size: var(--fs-xs); z-index: var(--z-sticky); pointer-events: none;
  opacity: 0; transition: opacity var(--t-base);
}
#pageIndicator.show { opacity: 1; }

/* ---- Empty state ---- */
#emptyState {
  position: absolute; inset: 0; display: flex; align-items: center; justify-content: center;
  z-index: var(--z-panel);
}

/* ---- Responsive (panels stay in the grid — never overlap the toolbar) ---- */
@media (max-width: 1320px) { #left { width: 232px; } #right { width: 256px; } }
@media (max-width: 1140px) { #left { width: 208px; } #right { width: 224px; } }
@media (max-width: 980px) { #left:not(.collapsed) { width: 200px; } #right.auto-collapse { width: 0; border-left: none; } }