/* ===== App Shell ===== */
.app { display: flex; flex-direction: column; height: 100vh; }

/* ===== Glassmorphism Header ===== */
.header {
  height: var(--header-h);
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--gray-200);
  display: flex;
  align-items: center;
  padding: 0 var(--sp-5);
  gap: var(--sp-4);
  z-index: 100;
  flex-shrink: 0;
  position: sticky;
  top: 0;
}

.header-logo {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--brand);
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  white-space: nowrap;
  cursor: pointer;
  transition: opacity var(--transition-fast);
  user-select: none;
}
.header-logo:hover { opacity: 0.8; }
.header-logo .logo-icon { display: flex; align-items: center; }

/* ===== Search with kbd badge ===== */
.header-search {
  flex: 1;
  max-width: 480px;
  position: relative;
}
.header-search input {
  width: 100%;
  padding: 8px 70px 8px 38px;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  outline: none;
  background: var(--gray-100);
  color: var(--gray-800);
  transition: all var(--transition);
}
.header-search input::placeholder { color: var(--gray-400); }
.header-search input:focus {
  border-color: var(--brand-300);
  background: white;
  box-shadow: var(--focus-ring);
}
.header-search .search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--gray-400);
  display: flex;
  align-items: center;
  pointer-events: none;
}
.header-search .search-kbd {
  position: absolute;
  right: 10px;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  gap: 3px;
  pointer-events: none;
  transition: opacity var(--transition-fast);
}
.header-search input:focus ~ .search-kbd { opacity: 0; }
.header-search .kbd {
  display: inline-flex;
  align-items: center;
  padding: 2px 6px;
  font-size: 0.7rem;
  font-family: var(--font-sans);
  font-weight: 500;
  color: var(--gray-400);
  background: white;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius-xs);
  line-height: 1.2;
  box-shadow: 0 1px 0 var(--gray-200);
}

/* ===== Header Actions ===== */
.header-actions {
  display: flex;
  gap: var(--sp-2);
  margin-left: auto;
  align-items: center;
}

/* ===== Button System ===== */
.btn {
  padding: 7px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 500;
  border: none;
  transition: all var(--transition);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  white-space: nowrap;
  position: relative;
}
.btn:active { transform: scale(0.97); }

.btn-primary {
  background: var(--brand);
  color: white;
  box-shadow: 0 1px 2px rgba(99,102,241,0.3);
}
.btn-primary:hover {
  background: var(--brand-600);
  box-shadow: 0 2px 8px rgba(99,102,241,0.35);
  transform: translateY(-1px);
}
.btn-primary:active { transform: translateY(0) scale(0.98); }

.btn-secondary {
  background: white;
  color: var(--gray-700);
  border: 1px solid var(--gray-200);
  box-shadow: var(--shadow-xs);
}
.btn-secondary:hover {
  background: var(--gray-50);
  border-color: var(--gray-300);
  box-shadow: var(--shadow-sm);
}

.btn-danger {
  background: var(--red);
  color: white;
  box-shadow: 0 1px 2px rgba(239,68,68,0.3);
}
.btn-danger:hover {
  background: #DC2626;
  box-shadow: 0 2px 8px rgba(239,68,68,0.3);
}

.btn-ghost {
  background: transparent;
  color: var(--gray-600);
  border: none;
}
.btn-ghost:hover {
  background: var(--gray-100);
  color: var(--gray-800);
}

.btn-sm { padding: 5px 12px; font-size: 0.8rem; }
.btn-xs { padding: 3px 8px; font-size: 0.75rem; }

/* ===== Content Area ===== */
.content { display: flex; flex: 1; overflow: hidden; }

/* ===== Sidebar ===== */
.sidebar {
  width: var(--sidebar-w);
  background: white;
  border-right: 1px solid var(--gray-200);
  overflow-y: auto;
  flex-shrink: 0;
  transition: width var(--transition-slow);
  display: flex;
  flex-direction: column;
}
.sidebar.collapsed { width: 0; overflow: hidden; }

.sidebar-section {
  padding: var(--sp-3) var(--sp-4);
  border-bottom: 1px solid var(--gray-100);
}

.sidebar-section-title {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--gray-400);
  margin-bottom: var(--sp-2);
  padding-left: var(--sp-1);
}

/* Sidebar item with active indicator bar */
.sidebar-item {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  padding: 7px 10px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 0.88rem;
  color: var(--gray-600);
  transition: all var(--transition-fast);
  position: relative;
  margin-bottom: 1px;
}
.sidebar-item:hover {
  background: var(--gray-100);
  color: var(--gray-800);
}
.sidebar-item.active {
  background: var(--brand-50);
  color: var(--brand);
  font-weight: 600;
}
.sidebar-item.active::before {
  content: '';
  position: absolute;
  left: -16px;
  top: 4px;
  bottom: 4px;
  width: 3px;
  background: var(--brand);
  border-radius: 0 var(--radius-full) var(--radius-full) 0;
}
.sidebar-item .item-icon {
  display: flex;
  align-items: center;
  color: inherit;
  flex-shrink: 0;
}
.sidebar-item .count {
  margin-left: auto;
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--gray-400);
  background: var(--gray-100);
  padding: 1px 7px;
  border-radius: var(--radius-full);
  min-width: 20px;
  text-align: center;
}
.sidebar-item.active .count {
  background: var(--brand-100);
  color: var(--brand-600);
}

.sidebar-add-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 10px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 0.85rem;
  color: var(--gray-400);
  border: 1px dashed var(--gray-300);
  background: transparent;
  width: 100%;
  transition: all var(--transition-fast);
  margin-top: var(--sp-1);
}
.sidebar-add-btn:hover {
  border-color: var(--brand-300);
  color: var(--brand);
  background: var(--brand-50);
}

/* ===== Main ===== */
.main {
  flex: 1;
  overflow-y: auto;
  padding: var(--sp-5) var(--sp-6);
}

/* ===== Sidebar Stats ===== */
.sidebar-stats {
  font-size: 0.8rem;
  color: var(--gray-500);
  display: flex;
  flex-direction: column;
  gap: var(--sp-1);
}
.sidebar-stats span {
  display: flex;
  justify-content: space-between;
  padding: 2px var(--sp-1);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .sidebar {
    position: absolute;
    z-index: 50;
    height: calc(100vh - var(--header-h));
    box-shadow: var(--shadow-xl);
  }
  .sidebar.collapsed { width: 0; }
  .header-search .search-kbd { display: none; }
}