/* ========================================
   三栏布局：大纲 | 编辑器 | AI 侧边栏
   ======================================== */

/* --- 顶栏 --- */
.topbar {
  height: var(--topbar-height);
  display: flex;
  align-items: center;
  padding: 0 var(--space-4);
  border-bottom: 1px solid var(--color-border-light);
  background: rgba(248, 252, 255, 0.94);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  z-index: 100;
  gap: var(--space-3);
  box-shadow: 0 1px 0 rgba(24, 50, 74, 0.04);
}

.topbar-logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 400;
  font-size: var(--text-lg);
  color: var(--color-text-primary);
  flex-shrink: 0;
  padding-right: var(--space-4);
  font-family: var(--font-display);
}

.topbar-logo svg,
.topbar-logo img {
  width: 28px;
  height: 28px;
  display: block;
  object-fit: contain;
}

.topbar-logo svg {
  color: var(--color-accent);
}

.topbar-divider {
  width: 1px;
  height: 24px;
  background: var(--color-border);
  flex-shrink: 0;
}

.topbar-title {
  flex: 1;
  display: flex;
  align-items: center;
  min-width: 0;
}

.topbar-title input {
  width: 100%;
  max-width: 400px;
  border: 1px solid transparent;
  padding: 8px 12px;
  border-radius: 8px;
  font-size: var(--text-md);
  font-weight: 500;
  color: var(--color-text-primary);
  background: transparent;
  transition: all var(--transition-fast);
}

.topbar-title input:hover {
  background: rgba(255, 255, 255, 0.8);
}

.topbar-title input:focus {
  background: white;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 1px var(--color-primary);
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-shrink: 0;
}

.topbar-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.topbar-btn:hover {
  background: rgba(255, 255, 255, 0.8);
  color: var(--color-text-primary);
  transform: none;
}

.topbar-btn:active {
  transform: scale(0.96);
}

.topbar-btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 2px rgba(47, 111, 159, 0.16);
  background: rgba(255, 255, 255, 0.92);
  color: var(--color-text-primary);
}

.topbar-btn svg {
  width: 18px;
  height: 18px;
}

.topbar-btn--primary {
  background: var(--color-primary);
  color: var(--color-text-inverse);
  box-shadow: none;
  border: 1px solid var(--color-primary);
}

.topbar-btn--primary:hover {
  background: var(--color-primary-hover);
  color: var(--color-text-inverse);
  box-shadow: none;
  transform: none;
}