/* Styles for the workflow library sidebar, workflow cards, modals, toasts,
   and the editor toolbar. Companion to workflowLibrary.js and libraryUI.js. */

/* CSS custom properties that define the colour palette and key dimensions for
   the sidebar. Dark-theme overrides are applied immediately below via .darkTheme. */
:root {
  --lib-bg:              #f8f9fa;
  --lib-border:          #dee2e6;
  --lib-active-bg:       #e8f0fe;
  --lib-active-border:   #448cfb;
  --lib-text:            #212529;
  --lib-meta-text:       #6c757d;
  --lib-hover-bg:        #f0f4ff;
  --lib-btn-icon-color:  #495057;
  --lib-width:           260px;
  --lib-width-collapsed: 36px;
}

.darkTheme {
  --lib-bg:              rgb(37, 37, 38);
  --lib-border:          rgb(60, 60, 60);
  --lib-active-bg:       rgb(28, 56, 120);
  --lib-active-border:   #448cfb;
  --lib-text:            #d4d4d4;
  --lib-meta-text:       #9e9e9e;
  --lib-hover-bg:        rgb(42, 45, 62);
  --lib-btn-icon-color:  #cccccc;
}

/* Root layout — body and app-container fill the entire viewport with no
   scroll so each panel can manage its own overflow independently. */

body {
  margin: 0;
  overflow: hidden;
}

.app-container {
  display: flex;
  flex-direction: row;
  height: 100vh;
  width: 100vw;
  overflow: hidden;
}

/* Library sidebar — fixed-width column on the left. Smoothly animates to a
   narrow collapsed strip when the user clicks the toggle. */

#library-sidebar {
  width: var(--lib-width);
  min-width: var(--lib-width);
  max-width: var(--lib-width);
  height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--lib-bg);
  border-right: 1px solid var(--lib-border);
  transition: width 0.2s ease, min-width 0.2s ease, max-width 0.2s ease;
  overflow: hidden;
  flex-shrink: 0;
  z-index: 2;
}

#library-sidebar.collapsed {
  width: var(--lib-width-collapsed);
  min-width: var(--lib-width-collapsed);
  max-width: var(--lib-width-collapsed);
}

#library-sidebar.collapsed .library-title,
#library-sidebar.collapsed .library-actions,
#library-sidebar.collapsed .library-search,
#library-sidebar.collapsed .library-filter-bar,
#library-sidebar.collapsed #lib-workflow-list,
#library-sidebar.collapsed .library-footer-text,
#library-sidebar.collapsed .quota-bar-container,
#library-sidebar.collapsed .sidebar-ctrl-label {
  display: none;
}

/* Split host — the editor+diagram flex area */
.split-host {
  flex: 1;
  display: flex;
  flex-direction: row;
  height: 100vh;
  overflow: hidden;
  min-width: 0;
}

/* Sidebar header — the "Workflows" label and the collapse/expand toggle button. */

.library-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 12px 8px;
  border-bottom: 1px solid var(--lib-border);
  flex-shrink: 0;
}

.library-title {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--lib-meta-text);
  white-space: nowrap;
}

#sidebar-collapse-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--lib-btn-icon-color);
  font-size: 14px;
  padding: 2px 4px;
  line-height: 1;
  border-radius: 3px;
  flex-shrink: 0;
}

#sidebar-collapse-btn:hover {
  background-color: var(--lib-hover-bg);
}

/* Sidebar action buttons — "New" and "Import" sit side-by-side just below
   the sidebar header. */

.library-actions {
  display: flex;
  gap: 6px;
  padding: 8px 10px 6px;
  flex-shrink: 0;
}

.library-actions .btn {
  flex: 1;
  font-size: 11px;
  padding: 3px 6px;
}

/* Search bar — a small text input with an inline clear button for filtering
   the workflow list in real time. */

.library-search {
  display: flex;
  align-items: center;
  margin: 0 10px 6px;
  border: 1px solid var(--lib-border);
  border-radius: 4px;
  overflow: hidden;
  flex-shrink: 0;
  background-color: var(--lib-bg);
}

#lib-search-input {
  flex: 1;
  border: none;
  outline: none;
  padding: 5px 8px;
  font-size: 12px;
  background-color: transparent;
  color: var(--lib-text);
  min-width: 0;
}

#lib-search-input::placeholder {
  color: var(--lib-meta-text);
}

#lib-search-clear {
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px 7px;
  color: var(--lib-meta-text);
  font-size: 12px;
  line-height: 1;
  flex-shrink: 0;
}

#lib-search-clear:hover { color: var(--lib-text); }

/* Sort dropdown — lets the user choose how the workflow list is ordered
   (recently modified, by name, by creation date, etc.). */

.library-filter-bar {
  padding: 0 10px 6px;
  flex-shrink: 0;
}

#lib-sort-select {
  width: 100%;
  font-size: 11px;
  padding: 3px 6px;
  border: 1px solid var(--lib-border);
  border-radius: 4px;
  background-color: var(--lib-bg);
  color: var(--lib-text);
  cursor: pointer;
}

/* Workflow list — the scrollable <ul> that holds all workflow cards.
   Uses a thin custom scrollbar to avoid layout interference. */

.library-workflow-list {
  list-style: none;
  margin: 0;
  padding: 0;
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
}

.library-workflow-list::-webkit-scrollbar { width: 4px; }
.library-workflow-list::-webkit-scrollbar-thumb {
  background-color: var(--lib-border);
  border-radius: 2px;
}

/* Workflow card — each list item shows the name, optional description, and
   metadata (state count, last modified). A coloured left border marks the
   active workflow, and action buttons appear on hover. */

.workflow-item {
  display: flex;
  flex-direction: column;
  padding: 8px 10px 6px;
  cursor: pointer;
  border-left: 3px solid transparent;
  border-bottom: 1px solid var(--lib-border);
  transition: background-color 0.22s ease, border-left-color 0.22s ease;
}

.workflow-item:hover {
  background-color: var(--lib-hover-bg);
}

.workflow-item.active {
  border-left-color: var(--lib-active-border);
  background-color: var(--lib-active-bg);
}

.workflow-item-main {
  display: flex;
  flex-direction: column;
  gap: 3px;
  min-width: 0;
}

/* Title row: name + inline rename button */
.workflow-item-header {
  display: flex;
  align-items: center;
  gap: 4px;
  min-width: 0;
}

.workflow-item-name {
  flex: 1;
  min-width: 0;
  font-size: 12px;
  font-weight: 600;
  color: var(--lib-text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Inline rename pencil — fades in on row hover */
.btn-rename-inline {
  flex-shrink: 0;
  background: none;
  border: 1px solid transparent;
  border-radius: 3px;
  cursor: pointer;
  padding: 2px 4px;
  color: var(--lib-meta-text);
  font-size: 10px;
  line-height: 1;
  display: inline-flex;
  align-items: center;
  opacity: 0;
  transition: opacity 0.2s ease, color 0.2s ease, background-color 0.2s ease;
}

.workflow-item:hover .btn-rename-inline,
.workflow-item.active .btn-rename-inline {
  opacity: 1;
}

.btn-rename-inline:hover {
  color: var(--lib-active-border);
  background-color: var(--lib-hover-bg);
  border-color: var(--lib-border);
}

.workflow-item-description {
  font-size: 10px;
  color: var(--lib-meta-text);
  font-style: italic;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  opacity: 0.9;
}

.workflow-item-meta {
  font-size: 10px;
  color: var(--lib-meta-text);
}

/* Action buttons — 3-button row, hidden until hover or active */
.workflow-item-actions {
  display: none;
  flex-wrap: nowrap;
  gap: 5px;
  margin-top: 7px;
  padding-top: 7px;
  border-top: 1px solid var(--lib-border);
  align-items: center;
}

.workflow-item:hover .workflow-item-actions,
.workflow-item.active .workflow-item-actions {
  display: flex;
}

/* Base style for the 3 action buttons (icon + label) */
.btn-icon {
  background: none;
  border: 1px solid var(--lib-border);
  border-radius: 4px;
  cursor: pointer;
  padding: 3px 8px;
  font-size: 11px;
  color: var(--lib-btn-icon-color);
  line-height: 1.4;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
  flex-shrink: 0;
  white-space: nowrap;
}

.btn-icon:hover {
  background-color: var(--lib-hover-bg);
  border-color: var(--lib-active-border);
  color: var(--lib-text);
}

.btn-icon .fa {
  font-size: 11px;
  opacity: 0.8;
}

.btn-icon.danger:hover {
  background-color: #f8d7da;
  border-color: #f5c6cb;
  color: #721c24;
}

.darkTheme .btn-icon.danger:hover {
  background-color: rgba(220, 53, 69, 0.2);
  border-color: rgba(220, 53, 69, 0.5);
  color: #f1aeb5;
}

/* Empty state — centred placeholder displayed when no workflows exist or
   when a search returns no results. */

.library-empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 40px 16px;
  text-align: center;
  color: var(--lib-meta-text);
  font-size: 12px;
  gap: 6px;
}

.library-empty-state-icon {
  font-size: 28px;
  opacity: 0.4;
}

/* Sidebar footer — shows the workflow count, storage used, and the quota
   progress bar. Hidden when the sidebar is collapsed. */

.library-footer {
  padding: 8px 10px;
  border-top: 1px solid var(--lib-border);
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.library-footer-text {
  font-size: 10px;
  color: var(--lib-meta-text);
}


/* Theme and full-screen controls — a row of icon+label buttons at the very
   bottom of the sidebar. When the sidebar is collapsed they stack vertically
   and show icons only. */

.sidebar-view-controls {
  display: flex;
  flex-direction: row;
  gap: 6px;
  padding: 8px 10px;
  border-top: 1px solid var(--lib-border);
  flex-shrink: 0;
}

.sidebar-ctrl-btn {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 6px 8px;
  background: none;
  border: 1px solid var(--lib-border);
  border-radius: 6px;
  cursor: pointer;
  font-size: 11px;
  color: var(--lib-btn-icon-color);
  white-space: nowrap;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.sidebar-ctrl-btn:hover {
  background-color: var(--lib-hover-bg);
  border-color: var(--lib-active-border);
  color: var(--lib-text);
}

.sidebar-ctrl-btn .fa {
  font-size: 13px;
  flex-shrink: 0;
}

/* Collapsed: stack buttons vertically, icon only */
#library-sidebar.collapsed .sidebar-view-controls {
  flex-direction: column;
  align-items: center;
  padding: 6px 0;
  gap: 6px;
  border-top: 1px solid var(--lib-border);
}

#library-sidebar.collapsed .sidebar-ctrl-btn {
  flex: none;
  width: 28px;
  height: 28px;
  padding: 0;
  border-radius: 6px;
}

/* Provider badge — a small warning label in the sidebar footer shown when the
   app fell back to sessionStorage or in-memory storage. */

.provider-badge {
  font-size: 10px;
  padding: 2px 6px;
  border-radius: 3px;
  display: inline-block;
  margin-top: 2px;
}

.provider-badge.session {
  background-color: #fff3cd;
  color: #856404;
  border: 1px solid #ffc107;
}

.provider-badge.memory {
  background-color: #ffe5d0;
  color: #7d4301;
  border: 1px solid #fd7e14;
}

/* Storage quota bar — a thin progress bar that fills as localStorage usage
   grows. Turns yellow at 80 % full and red at 95 %. */

.quota-bar-container {
  height: 3px;
  background-color: var(--lib-border);
  border-radius: 2px;
  overflow: hidden;
}

.quota-bar-fill {
  height: 100%;
  border-radius: 2px;
  transition: width 0.3s ease, background-color 0.3s ease;
  background-color: #28a745;
  width: 0%;
}

.quota-bar-fill.warn   { background-color: #ffc107; }
.quota-bar-fill.danger { background-color: #dc3545; }

/* Editor column — the left panel of the split view. The Monaco editor card
   grows to fill whatever height remains after the toolbar. */

#editor-col {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  min-width: 0;
}

#editor-col .card {
  flex: 1 !important;
  display: flex !important;
  flex-direction: column !important;
  overflow: hidden;
  margin-bottom: 0 !important;
  border-radius: 0;
  border: none;
}

#editor-col .card-body {
  flex: 1 !important;
  height: auto !important;
  overflow: hidden;
  position: relative;
}

/* Editor toolbar — the slim bar above Monaco showing the active workflow name,
   autosave status, and the Format / Generate Diagram buttons. */

#editor-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 4px 10px;
  border-bottom: 1px solid var(--lib-border);
  background-color: var(--lib-bg);
  flex-shrink: 0;
  min-height: 36px;
  gap: 8px;
}

.toolbar-left {
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 0;
  flex: 1;
}

.workflow-name-display {
  font-size: 12px;
  font-weight: 600;
  color: var(--lib-text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 180px;
}

.autosave-status {
  font-size: 10px;
  white-space: nowrap;
  transition: opacity 0.4s ease;
}

.autosave-status.status-dirty  { color: #856404; }
.autosave-status.status-saving { color: var(--lib-meta-text); }
.autosave-status.status-saved  { color: #155724; }
.autosave-status.status-error  { color: #721c24; }

.toolbar-right {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-shrink: 0;
}

.toolbar-right .btn {
  font-size: 11px;
  padding: 2px 8px;
}

/* Unsaved changes banner — a yellow strip that appears above the editor when
   the user tries to navigate away from a workflow with unsaved edits. */

#unsaved-banner {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 5px 12px;
  background-color: #fff3cd;
  border-bottom: 1px solid #ffc107;
  font-size: 12px;
  color: #856404;
  flex-shrink: 0;
  flex-wrap: wrap;
}

#unsaved-banner.visible { display: flex; }

#unsaved-banner .btn {
  font-size: 11px;
  padding: 2px 8px;
}

/* Quota warning banner — a Bootstrap alert repurposed as a full-width strip.
   Resets Bootstrap's default margin so it sits flush in the flex column. */

#quota-banner {
  flex-shrink: 0;
  border-radius: 0 !important;
  margin-bottom: 0 !important;
  font-size: 12px;
}

/* Toast notifications — a stack of brief pop-up messages fixed to the
   bottom-right corner. Each toast slides in and fades out automatically. */

#toast-container {
  position: fixed;
  bottom: 20px;
  right: 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  z-index: 9999;
  pointer-events: none;
  max-width: 340px;
}

.toast {
  pointer-events: auto;
  padding: 10px 14px;
  border-radius: 6px;
  font-size: 12px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
  animation: toast-in 0.2s ease;
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

@keyframes toast-in {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

.toast.success { background: #d4edda; color: #155724; border: 1px solid #c3e6cb; }
.toast.info    { background: #d1ecf1; color: #0c5460; border: 1px solid #bee5eb; }
.toast.warning { background: #fff3cd; color: #856404; border: 1px solid #ffc107; }
.toast.error   { background: #f8d7da; color: #721c24; border: 1px solid #f5c6cb; }

.toast-dismiss {
  margin-left: auto;
  background: none;
  border: none;
  cursor: pointer;
  font-size: 14px;
  color: inherit;
  opacity: 0.6;
  padding: 0;
  line-height: 1;
  flex-shrink: 0;
}

.toast-dismiss:hover { opacity: 1; }

/* Plain-JS modal support — Bootstrap 4 modals normally rely on Bootstrap JS
   to show/hide. Since we don't load that, we drive the show/hide state
   ourselves with these rules. */

.modal {
  display: none;
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  z-index: 1050;
  overflow-x: hidden;
  overflow-y: auto;
  outline: 0;
}

.modal.show {
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-backdrop {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background-color: rgba(0,0,0,0.5);
  z-index: 1040;
}

.modal-backdrop.show { display: block !important; }

/* Sizing: wider and more comfortable by default */
.modal .modal-dialog {
  max-width: 560px;
  width: calc(100% - 2rem);
}

.modal .modal-dialog.modal-sm {
  max-width: 420px;
}

#modal-import .modal-dialog {
  max-width: 660px;
}

/* Modal content — rounded, elevated */
.modal .modal-content {
  background-color: var(--lib-bg);
  color: var(--lib-text);
  border: 1px solid var(--lib-border);
  border-radius: 10px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2);
  overflow: hidden;
}

/* Modal sections */
.modal .modal-header {
  padding: 1.1rem 1.5rem;
  border-bottom: 1px solid var(--lib-border);
  align-items: center;
}

.modal .modal-title {
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.modal .modal-body {
  padding: 1.5rem;
}

.modal .modal-footer {
  padding: 0.9rem 1.5rem;
  border-top: 1px solid var(--lib-border);
  gap: 0.5rem;
}

/* Form controls inside modals */
.modal .form-group {
  margin-bottom: 1.25rem;
}

.modal .form-group:last-child {
  margin-bottom: 0;
}

.modal label {
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 0.4rem;
  color: var(--lib-text);
}

.modal .form-control {
  background-color: var(--lib-bg);
  color: var(--lib-text);
  border-color: var(--lib-border);
  font-size: 13px;
  padding: 0.45rem 0.75rem;
  border-radius: 6px;
}

.modal .form-control:focus {
  background-color: var(--lib-bg);
  color: var(--lib-text);
  border-color: var(--lib-active-border);
  box-shadow: 0 0 0 3px rgba(68, 140, 251, 0.15);
}

.modal textarea.form-control {
  resize: vertical;
  min-height: 80px;
}

.modal .form-text {
  font-size: 11px;
  margin-top: 0.3rem;
}

/* Close button */
.modal .close {
  font-size: 1.2rem;
  opacity: 0.5;
  padding: 0.25rem;
  line-height: 1;
}

.modal .close:hover { opacity: 0.9; }

/* Import drop zone — the dashed-border drag-and-drop target inside the import
   modal. Highlights with a blue border when a file is dragged over it. */

.import-drop-zone {
  border: 2px dashed var(--lib-border);
  border-radius: 8px;
  padding: 28px 20px;
  text-align: center;
  font-size: 13px;
  color: var(--lib-meta-text);
  transition: border-color 0.15s ease, background-color 0.15s ease;
  cursor: default;
  background-color: transparent;
}

.import-drop-zone p {
  margin-bottom: 0.75rem;
  font-size: 13px;
}

.import-drop-zone.drag-over {
  border-color: #448cfb;
  background-color: var(--lib-active-bg);
}

#import-paste-area {
  font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace !important;
  font-size: 12px !important;
  min-height: 140px;
  resize: vertical;
}

/* Frosted-glass icon button — a small translucent button positioned absolutely
   inside a panel (editor or diagram area). Used for the format action. */

.editor-ctrl-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  z-index: 10;
  width: 30px;
  height: 30px;
  border-radius: 6px;
  border: 1px solid rgba(0, 0, 0, 0.1);
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  color: #495057;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.1);
  transition: background-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}

.editor-ctrl-btn:hover {
  background: rgba(255, 255, 255, 1);
  color: #212529;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.darkTheme .editor-ctrl-btn {
  background: rgba(45, 45, 48, 0.88);
  border-color: rgba(255, 255, 255, 0.1);
  color: #cccccc;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.3);
}

.darkTheme .editor-ctrl-btn:hover {
  background: rgba(65, 65, 68, 0.95);
  color: #ffffff;
}

/* Export dropdown — a small floating menu that appears below the Export button
   in a workflow card, offering JSON and Image export options. */

.export-dropdown {
  position: fixed;
  background: var(--lib-bg, #fff);
  border: 1px solid var(--lib-border, #dee2e6);
  border-radius: 8px;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
  min-width: 160px;
  padding: 4px;
  display: flex;
  flex-direction: column;
  z-index: 9999;
  animation: dropdown-in 0.12s ease;
}

@keyframes dropdown-in {
  from { opacity: 0; transform: translateY(-4px); }
  to   { opacity: 1; transform: translateY(0); }
}

.export-dropdown-item {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 8px 12px;
  background: none;
  border: none;
  cursor: pointer;
  font-size: 12px;
  color: var(--lib-text, #212529);
  border-radius: 5px;
  text-align: left;
  width: 100%;
  transition: background-color 0.15s ease;
}

.export-dropdown-item:hover {
  background-color: var(--lib-hover-bg, #f0f4ff);
}

.export-dropdown-item .fa {
  font-size: 13px;
  opacity: 0.7;
  width: 14px;
  text-align: center;
}

/* Diagram overlay controls — frosted-glass icon buttons for the top-right
   corner of the diagram panel. Kept here in case they're needed again;
   the theme and fullscreen controls currently live in the sidebar instead. */

.diagram-wrapper {
  position: relative;
}

.diagram-controls {
  position: absolute;
  top: 10px;
  right: 10px;
  display: flex;
  gap: 6px;
  z-index: 10;
}

.diagram-ctrl-btn {
  width: 34px;
  height: 34px;
  border-radius: 8px;
  border: 1px solid rgba(0, 0, 0, 0.1);
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  color: #495057;
  transition: background-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.1);
}

.diagram-ctrl-btn:hover {
  background: rgba(255, 255, 255, 1);
  color: #212529;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.darkTheme .diagram-ctrl-btn {
  background: rgba(45, 45, 48, 0.88);
  border-color: rgba(255, 255, 255, 0.1);
  color: #cccccc;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.3);
}

.darkTheme .diagram-ctrl-btn:hover {
  background: rgba(65, 65, 68, 0.95);
  color: #ffffff;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.4);
}

/* Responsive layout — on narrow screens the sidebar becomes a fixed overlay
   so it doesn't steal horizontal space from the editor and diagram panels. */

@media (max-width: 768px) {
  #library-sidebar {
    position: fixed;
    top: 0; left: 0;
    height: 100vh;
    transform: translateX(0);
    transition: transform 0.25s ease;
    z-index: 100;
    box-shadow: 2px 0 8px rgba(0,0,0,0.15);
  }

  #library-sidebar.collapsed {
    transform: translateX(calc(-1 * var(--lib-width) + var(--lib-width-collapsed)));
  }

  .split-host {
    flex-direction: column;
  }
}