/* ── Reset & Base ──────────────────────────────────────────── */

*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  height: 100%;
  background: #0e0d0c;
  color: var(--text-primary);
  font-family: var(--font-ui);
  font-size: 14px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow: hidden;
}

/* ── App Shell ─────────────────────────────────────────────── */

.app-shell {
  display: flex;
  flex-direction: column;
  height: 100vh;
  background: var(--bg-surface);
  margin: 6px;
  overflow: hidden;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
}

/* ── Title Bar ─────────────────────────────────────────────── */

.title-bar {
  display: flex;
  align-items: center;
  height: 40px;
  padding: 0 var(--space-md);
  background: var(--bg-elevated);
  border-bottom: 1px solid var(--border-subtle);
  -webkit-app-region: drag;
  flex-shrink: 0;
}

.traffic-lights {
  display: flex;
  gap: 8px;
  margin-right: var(--space-lg);
}

.traffic-light {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  cursor: pointer;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: filter 0.15s;
}

.traffic-light:hover { filter: brightness(1.2); }

.traffic-light::after {
  content: '';
  font-size: 8px;
  font-weight: 700;
  line-height: 1;
  color: rgba(0, 0, 0, 0.7);
  opacity: 0;
  transition: opacity 0.1s;
}

.traffic-lights:hover .traffic-light::after {
  opacity: 1;
}

.traffic-light--close { background: #c45b54; }
.traffic-light--close::after { content: '\00d7'; font-size: 10px; }
.traffic-light--minimize { background: #c4a43e; }
.traffic-light--minimize::after { content: '\2013'; font-size: 9px; margin-top: -1px; }
.traffic-light--maximize { background: #5eab5e; }
.traffic-light--maximize::after { content: '\2922'; font-size: 7px; }

.title-bar__text {
  flex: 1;
  text-align: center;
  font-size: 12px;
  color: var(--text-muted);
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

.title-bar__badge {
  font-size: 10px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--accent);
  color: var(--accent);
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* ── Main Layout ───────────────────────────────────────────── */

.main-layout {
  display: flex;
  flex: 1;
  overflow: hidden;
}

/* ── Sidebar ───────────────────────────────────────────────── */

.sidebar {
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  background: var(--bg-surface);
  border-right: 1px solid var(--border-subtle);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.sidebar__header {
  padding: var(--space-sm) var(--space-md);
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border-subtle);
  flex-shrink: 0;
  font-family: var(--font-mono);
}

.sidebar__tree {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-xs) 0;
}

/* Custom scrollbar */
.sidebar__tree::-webkit-scrollbar { width: 5px; }
.sidebar__tree::-webkit-scrollbar-track { background: transparent; }
.sidebar__tree::-webkit-scrollbar-thumb {
  background: var(--border-default);
  border-radius: 2px;
}
.sidebar__tree::-webkit-scrollbar-thumb:hover {
  background: var(--border-strong);
}

/* ── Content Area ──────────────────────────────────────────── */

.content-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--bg-base);
}

/* Tab bar */
.tab-bar {
  display: flex;
  align-items: stretch;
  height: 36px;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-subtle);
  padding-left: 0;
  flex-shrink: 0;
  overflow-x: auto;
  scrollbar-width: none;
}

.tab-bar::-webkit-scrollbar {
  display: none;
}

.tab {
  display: flex;
  align-items: center;
  gap: 5px;
  height: 100%;
  padding: 0 var(--space-sm) 0 var(--space-md);
  font-size: 12px;
  color: var(--text-muted);
  border-right: 1px solid var(--border-subtle);
  border-bottom: 2px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  font-family: var(--font-mono);
  transition: color 0.1s, background 0.1s;
  min-width: 0;
  flex-shrink: 0;
  max-width: 160px;
}

.tab:hover {
  color: var(--text-secondary);
  background: var(--bg-hover);
}

.tab:hover .tab__close {
  opacity: 1;
}

.tab.active {
  color: var(--text-bright);
  background: var(--bg-base);
  margin-bottom: -1px;
}

.tab__dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
  opacity: 0.6;
  flex-shrink: 0;
}

.tab__icon {
  display: flex;
  align-items: center;
  line-height: 0;
  opacity: 0.5;
}

.tab__icon svg {
  display: block;
}

.tab.active .tab__icon {
  opacity: 0.8;
}

.tab__label {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
}

.tab__close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 16px;
  height: 16px;
  border-radius: 2px;
  font-size: 14px;
  line-height: 1;
  opacity: 0;
  color: var(--text-muted);
  transition: opacity 0.1s, background 0.1s, color 0.1s;
  flex-shrink: 0;
  margin-left: 2px;
}

.tab__close:hover {
  background: var(--bg-active);
  color: var(--text-primary);
}

/* Content scroll area */
.content-scroll {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-xl) var(--space-2xl);
}

.content-scroll::-webkit-scrollbar { width: 6px; }
.content-scroll::-webkit-scrollbar-track { background: transparent; }
.content-scroll::-webkit-scrollbar-thumb {
  background: var(--border-default);
  border-radius: 3px;
}
.content-scroll::-webkit-scrollbar-thumb:hover {
  background: var(--border-strong);
}

/* ── Responsive ────────────────────────────────────────────── */

@media (max-width: 768px) {
  .app-shell {
    margin: 0;
    border-radius: 0;
    border: none;
  }

  .title-bar__text {
    font-size: 11px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .traffic-lights {
    margin-right: var(--space-sm);
  }

  .main-layout {
    flex-direction: column;
  }

  .sidebar {
    width: 100%;
    min-width: 100%;
    max-height: 35vh;
    border-right: none;
    border-bottom: 1px solid var(--border-subtle);
  }

  .content-scroll {
    padding: var(--space-md);
  }
}