/* ── CSS Variables ── */
:root {
  --bg-deep: #1a1b1e;
  --bg-primary: #1e1f22;
  --bg-secondary: #2b2d31;
  --bg-tertiary: #313338;
  --text-normal: #dbdee1;
  --text-muted: #949ba4;
  --text-faint: #6d6f78;
  --accent: #e67e22;
  --accent-rgb: 230, 126, 34;
  --accent-hover: #d35400;
  --success: #57d28f;
  --danger: #ed4245;
  --warning: #fee75c;
  --border: rgba(255, 255, 255, 0.06);
  --radius: 8px;
  --radius-lg: 12px;
  --transition: 150ms ease;
  --font: 'Segoe UI', system-ui, -apple-system, sans-serif;
  --header-height: 56px;
}

/* ── Reset & Base ── */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  height: 100%;
  font-family: var(--font);
  font-size: 15px;
  color: var(--text-normal);
  background: var(--bg-deep);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow: hidden;
}

#root {
  height: 100%;
}

/* ── App Shell ── */
.hub-app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

/* ── Header ── */
.hub-header {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  height: var(--header-height);
  min-height: var(--header-height);
  padding: 0 16px;
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border);
  gap: 16px;
}

.hub-header-left {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.hub-logo {
  font-size: 24px;
  line-height: 1;
}

.hub-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-normal);
  letter-spacing: -0.02em;
  white-space: nowrap;
}

/* ── Connection Status Dot ── */
.hub-conn-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--danger);
  flex-shrink: 0;
  transition: background var(--transition);
  box-shadow: 0 0 0 2px rgba(237, 66, 69, 0.25);
}

.hub-conn-dot.online {
  background: var(--success);
  box-shadow: 0 0 0 2px rgba(87, 210, 143, 0.25);
  animation: pulse-dot 2s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%, 100% {
    box-shadow: 0 0 0 2px rgba(87, 210, 143, 0.25);
  }
  50% {
    box-shadow: 0 0 0 6px rgba(87, 210, 143, 0.1);
  }
}

/* ── Tab Navigation ── */
.hub-tabs {
  display: flex;
  align-items: center;
  gap: 4px;
  flex: 1;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
  padding: 0 4px;
}

.hub-tabs::-webkit-scrollbar {
  display: none;
}

.hub-tab {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-family: var(--font);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  border-radius: var(--radius);
  white-space: nowrap;
  transition: all var(--transition);
  position: relative;
  user-select: none;
}

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

.hub-tab.active {
  color: var(--accent);
  background: rgba(var(--accent-rgb), 0.1);
}

.hub-tab.active::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 50%;
  transform: translateX(-50%);
  width: calc(100% - 16px);
  height: 2px;
  background: var(--accent);
  border-radius: 1px;
}

.hub-tab-icon {
  font-size: 16px;
  line-height: 1;
}

.hub-tab-label {
  text-transform: capitalize;
}

/* ── Header Right ── */
.hub-header-right {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.hub-version {
  font-size: 12px;
  color: var(--text-faint);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
  background: var(--bg-secondary);
  padding: 4px 8px;
  border-radius: 4px;
}

/* ── Main Content Area ── */
.hub-content {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  background: var(--bg-deep);
  scrollbar-width: thin;
  scrollbar-color: var(--bg-tertiary) transparent;
}

.hub-content::-webkit-scrollbar {
  width: 6px;
}

.hub-content::-webkit-scrollbar-track {
  background: transparent;
}

.hub-content::-webkit-scrollbar-thumb {
  background: var(--bg-tertiary);
  border-radius: 3px;
}

.hub-content::-webkit-scrollbar-thumb:hover {
  background: var(--text-faint);
}

/* ── Empty State ── */
.hub-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  min-height: 300px;
  text-align: center;
  padding: 32px;
  animation: fade-in 300ms ease;
}

.hub-empty-icon {
  font-size: 64px;
  line-height: 1;
  margin-bottom: 20px;
  opacity: 0.6;
  filter: grayscale(30%);
}

.hub-empty h2 {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-normal);
  margin-bottom: 8px;
}

.hub-empty p {
  font-size: 15px;
  color: var(--text-muted);
  max-width: 360px;
  line-height: 1.5;
}

/* ── Animations ── */
@keyframes fade-in {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ── Selection ── */
::selection {
  background: rgba(var(--accent-rgb), 0.3);
  color: var(--text-normal);
}

/* ── Focus Styles ── */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ── Responsive ── */
@media (max-width: 768px) {
  :root {
    --header-height: 48px;
  }

  .hub-header {
    padding: 0 10px;
    gap: 8px;
  }

  .hub-title {
    font-size: 15px;
  }

  .hub-logo {
    font-size: 20px;
  }

  .hub-tab {
    padding: 6px 10px;
    font-size: 13px;
    gap: 4px;
  }

  .hub-tab-label {
    display: none;
  }

  .hub-tab-icon {
    font-size: 18px;
  }

  .hub-version {
    font-size: 11px;
  }

  .hub-empty-icon {
    font-size: 48px;
  }

  .hub-empty h2 {
    font-size: 18px;
  }

  .hub-empty p {
    font-size: 14px;
  }
}

@media (max-width: 480px) {
  .hub-header-right {
    display: none;
  }

  .hub-header {
    padding: 0 8px;
    gap: 6px;
  }

  .hub-title {
    font-size: 14px;
  }
}