.app-shell {
  display: grid;
  grid-template-rows: auto 1fr;
  min-height: 100vh;
}

.app-header {
  position: sticky;
  top: 0;
  z-index: var(--z-overlay);
  background: rgba(10, 14, 20, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
}

.app-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-6);
  gap: var(--space-6);
  max-width: 1800px;
  margin: 0 auto;
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--fs-md);
  letter-spacing: -0.01em;
}

.brand__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-cyan));
  color: var(--bg-base);
  font-weight: 800;
  font-size: var(--fs-sm);
}

.brand__name {
  color: var(--fg-primary);
}

.brand__sub {
  color: var(--fg-tertiary);
  font-weight: 400;
  font-size: var(--fs-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.tab-nav {
  display: flex;
  gap: 0;
  align-items: center;
  height: 100%;
}

.tab-nav__item {
  position: relative;
  padding: var(--space-3) var(--space-5);
  font-family: var(--font-display);
  font-size: var(--fs-sm);
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--fg-tertiary);
  text-transform: uppercase;
  transition: color var(--transition-fast);
}

.tab-nav__item::after {
  content: '';
  position: absolute;
  inset: auto 0 -1px 0;
  height: 2px;
  background: var(--accent-cyan);
  transform: scaleX(0);
  transform-origin: center;
  transition: transform var(--transition-base);
}

.tab-nav__item:hover {
  color: var(--fg-secondary);
}

.tab-nav__item--active {
  color: var(--fg-primary);
}

.tab-nav__item--active::after {
  transform: scaleX(1);
}

.app-header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  background: var(--bg-elev-1);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.lang-switch__btn {
  padding: var(--space-1) var(--space-3);
  font-family: var(--font-display);
  font-size: var(--fs-xs);
  font-weight: 600;
  color: var(--fg-tertiary);
  letter-spacing: 0.06em;
  transition: all var(--transition-fast);
  border-right: 1px solid var(--border-subtle);
}

.lang-switch__btn:last-child {
  border-right: none;
}

.lang-switch__btn--active {
  background: var(--bg-elev-3);
  color: var(--fg-primary);
}

.lang-switch__btn:not(.lang-switch__btn--active):hover {
  color: var(--fg-secondary);
  background: var(--bg-elev-2);
}

.app-content {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 0;
  max-width: 1800px;
  width: 100%;
  margin: 0 auto;
  min-height: calc(100vh - 53px);
}

.sidebar {
  border-right: 1px solid var(--border-subtle);
  background: var(--bg-elev-1);
  padding: var(--space-5) 0;
  overflow-y: auto;
}

.sidebar__section {
  padding: 0 var(--space-5);
  margin-bottom: var(--space-6);
}

.sidebar__heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-3);
}

.sidebar__title {
  font-family: var(--font-display);
  font-size: var(--fs-xs);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-tertiary);
}

.sidebar__action {
  width: 22px;
  height: 22px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  color: var(--fg-tertiary);
  transition: all var(--transition-fast);
  font-size: 16px;
  line-height: 1;
}

.sidebar__action:hover {
  background: var(--bg-elev-3);
  color: var(--fg-primary);
}

.strategy-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.strategy-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: var(--fs-base);
  color: var(--fg-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  border-left: 2px solid transparent;
}

.strategy-item:hover {
  background: var(--bg-elev-2);
  color: var(--fg-primary);
}

.strategy-item--active {
  background: var(--bg-elev-3);
  color: var(--fg-primary);
  border-left-color: var(--accent-cyan);
}

.strategy-item__name {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-family: var(--font-mono);
  font-size: var(--fs-base);
}

.strategy-item__status {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--status-inactive);
  flex-shrink: 0;
}

.strategy-item__status--active {
  background: var(--status-success);
  box-shadow: 0 0 8px rgba(74, 222, 128, 0.5);
}

.strategy-item__shared-badge {
  font-size: 10px;
  color: var(--accent-magenta);
  margin-right: var(--space-2);
}

.empty-list {
  padding: var(--space-4) var(--space-3);
  font-size: var(--fs-sm);
  color: var(--fg-tertiary);
  font-style: italic;
}

.editor {
  padding: var(--space-6) var(--space-8);
  overflow-y: auto;
  max-height: calc(100vh - 53px);
}

.editor__header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-5);
  border-bottom: 1px solid var(--border-subtle);
}

.editor__title-area {
  flex: 1;
  min-width: 0;
}

.editor__title-input {
  background: transparent;
  border: none;
  font-family: var(--font-display);
  font-size: var(--fs-2xl);
  font-weight: 700;
  color: var(--fg-primary);
  width: 100%;
  padding: 0;
  letter-spacing: -0.02em;
}

.editor__title-input:focus {
  outline: none;
  border-bottom: 1px solid var(--border-focus);
}

.editor__meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-top: var(--space-2);
  font-size: var(--fs-sm);
  color: var(--fg-tertiary);
}

.editor__actions {
  display: flex;
  gap: var(--space-2);
  flex-shrink: 0;
}

.toolbar {
  position: sticky;
  bottom: 0;
  display: flex;
  gap: var(--space-2);
  padding: var(--space-4) var(--space-8);
  background: rgba(10, 14, 20, 0.95);
  backdrop-filter: blur(8px);
  border-top: 1px solid var(--border-subtle);
  margin: var(--space-6) calc(var(--space-8) * -1) calc(var(--space-6) * -1);
}

.toolbar__spacer {
  flex: 1;
}

.editor__placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  height: 60vh;
  color: var(--fg-tertiary);
}

.editor__placeholder-mark {
  font-family: var(--font-display);
  font-size: 80px;
  font-weight: 700;
  letter-spacing: -0.04em;
  color: var(--bg-elev-3);
  margin-bottom: var(--space-4);
}

.editor__placeholder-text {
  font-size: var(--fs-md);
  text-align: center;
  max-width: 400px;
  line-height: var(--lh-relaxed);
}

@media (max-width: 1024px) {
  .app-content {
    grid-template-columns: 1fr;
  }
  .sidebar {
    display: none;
  }
  .editor {
    padding: var(--space-4);
  }
  .toolbar {
    margin: var(--space-4) calc(var(--space-4) * -1) calc(var(--space-4) * -1);
  }
}