/* ==========================================================================
   Layout: application shell (sidebar + header + workspace + status bar),
   responsive single-column transition, page scaffolds.
   ========================================================================== */

.app {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  grid-template-rows: var(--header-height) 1fr var(--statusbar-height);
  grid-template-areas:
    "sidebar header"
    "sidebar main"
    "sidebar statusbar";
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
}

/* Sidebar ----------------------------------------------------------------- */

.app-sidebar {
  grid-area: sidebar;
  display: flex;
  flex-direction: column;
  background: var(--color-surface);
  border-right: 1px solid var(--color-border);
  overflow-y: auto;
  z-index: var(--z-sidebar);
}

.app-brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  height: var(--header-height);
  padding: 0 var(--space-4);
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
}

.app-brand img,
.app-brand svg {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
}

.app-brand-name {
  font-size: var(--text-lg);
  font-weight: var(--weight-bold);
  letter-spacing: -0.01em;
  color: var(--color-text);
}

.app-brand-name span {
  color: var(--color-primary);
}

.app-nav {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-3) var(--space-2);
}

.app-nav-group-label {
  padding: var(--space-4) var(--space-3) var(--space-1);
  font-size: var(--text-xs);
  font-weight: var(--weight-semibold);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

.app-nav-link {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  min-height: var(--tap-target);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-button);
  color: var(--color-text-secondary);
  font-size: var(--text-base);
  font-weight: var(--weight-medium);
  text-decoration: none;
  transition: background var(--duration-fast) var(--ease), color var(--duration-fast) var(--ease);
}

.app-nav-link:hover {
  background: var(--color-surface-secondary);
  color: var(--color-text);
}

.app-nav-link[aria-current="page"] {
  background: var(--color-primary-light);
  color: var(--color-primary-deep);
}

[data-theme="dark"] .app-nav-link[aria-current="page"] {
  color: var(--color-primary);
}

.app-nav-link svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

.app-nav-badge {
  margin-left: auto;
  padding: 1px 8px;
  border-radius: var(--radius-pill);
  background: var(--color-danger);
  color: #fff;
  font-size: var(--text-xs);
  font-weight: var(--weight-semibold);
}

.app-sidebar-footer {
  margin-top: auto;
  padding: var(--space-3);
  border-top: 1px solid var(--color-border);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

/* Header ------------------------------------------------------------------ */

.app-header {
  grid-area: header;
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: 0 var(--space-4);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  z-index: var(--z-header);
}

.app-header .header-search {
  flex: 1;
  max-width: 420px;
}

.header-icon-btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: var(--tap-target);
  height: var(--tap-target);
  border-radius: var(--radius-button);
  color: var(--color-text-secondary);
  transition: background var(--duration-fast) var(--ease), color var(--duration-fast) var(--ease);
}

.header-icon-btn:hover {
  background: var(--color-surface-secondary);
  color: var(--color-text);
}

.header-icon-btn svg {
  width: 20px;
  height: 20px;
}

.header-icon-btn .badge-dot {
  position: absolute;
  top: 8px;
  right: 8px;
  width: 8px;
  height: 8px;
  border-radius: var(--radius-circle);
  background: var(--color-danger);
}

.header-user-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  height: var(--tap-target);
  padding: 0 var(--space-2) 0 var(--space-1);
  border-radius: var(--radius-button);
  color: var(--color-text);
  font-weight: var(--weight-medium);
}

.header-user-btn:hover {
  background: var(--color-surface-secondary);
}

/* Main workspace ---------------------------------------------------------- */

.app-main {
  grid-area: main;
  position: relative;
  overflow: hidden;
  background: var(--color-bg);
}

.page {
  display: flex;
  flex-direction: column;
  height: 100%;
  overflow: hidden;
}

.page-scroll {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-6);
}

.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-5) var(--space-6) 0;
}

.page-header h1 {
  margin: 0;
}

.page-header .page-subtitle {
  margin-top: var(--space-1);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.page-body {
  padding: var(--space-5) var(--space-6) var(--space-8);
}

/* Context panel (right column on dialer) ---------------------------------- */

.context-panel {
  width: var(--context-panel-width);
  border-left: 1px solid var(--color-border);
  background: var(--color-surface);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.context-panel[hidden] {
  display: none;
}

.context-panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4);
  border-bottom: 1px solid var(--color-border);
}

/* Status bar -------------------------------------------------------------- */

.app-statusbar {
  grid-area: statusbar;
  display: flex;
  align-items: center;
  gap: var(--space-5);
  padding: 0 var(--space-4);
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  overflow-x: auto;
  white-space: nowrap;
}

.status-item {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: var(--radius-circle);
  background: var(--color-text-muted);
  flex-shrink: 0;
}

.status-dot.is-success {
  background: var(--color-success);
}

.status-dot.is-warning {
  background: var(--color-warning);
}

.status-dot.is-danger {
  background: var(--color-danger);
}

.status-dot.is-info {
  background: var(--color-info);
}

/* Drawer (mobile navigation) ---------------------------------------------- */

.sidebar-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.45);
  z-index: calc(var(--z-drawer) - 1);
}

.nav-toggle {
  display: none;
}

/* Standalone page (login, offline) ---------------------------------------- */

.standalone {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  min-height: 100dvh;
  padding: var(--space-6);
  background: var(--color-bg);
}

/* Card grid helpers ------------------------------------------------------- */

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-4);
}

.split-view {
  display: grid;
  grid-template-columns: minmax(280px, 360px) 1fr;
  gap: 0;
  height: 100%;
  overflow: hidden;
}

.split-view > * {
  overflow-y: auto;
}

.split-view > *:first-child {
  border-right: 1px solid var(--color-border);
  background: var(--color-surface);
}