/* ViaTone Pulse — Premium Application Shell (Phase 1)
 * Dark sidebar + light-premium main canvas.
 * Backward-compatible: .a4u-* selectors retained alongside .pulse-* */

.a4u-app {
  display: flex;
  min-height: 100vh;
}

/* ═══════════════════════════════════════════════════════════════════════
   Sidebar — always dark regardless of theme
   ═══════════════════════════════════════════════════════════════════════ */
.a4u-sidebar {
  width: var(--pulse-sidebar-w);
  background: var(--pulse-sidebar);
  border-right: 1px solid var(--pulse-sidebar-border);
  display: flex;
  flex-direction: column;
  position: fixed;
  inset: 0 auto 0 0;
  z-index: 40;
  transition: transform var(--pulse-motion-base) var(--pulse-ease);
  color: #e2e4e8;
}

.a4u-sidebar__brand {
  padding: 20px 16px 16px;
  border-bottom: 1px solid var(--pulse-sidebar-border);
}

.a4u-sidebar__brand-link {
  display: block;
  text-decoration: none;
  color: inherit;
}

.a4u-sidebar__logo-img {
  display: block;
  width: min(100%, 188px);
  height: auto;
  max-height: 52px;
  object-fit: contain;
  object-position: left center;
}

.a4u-sidebar__logo {
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: #f4f5f6;
}

.a4u-sidebar__logo span {
  color: var(--pulse-primary);
}

.a4u-sidebar__tagline {
  font-size: 11px;
  color: rgba(255,255,255,0.5);
  margin-top: 8px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  line-height: 1.35;
}

.a4u-nav-item__brand-icon {
  display: block;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  object-fit: cover;
}

.a4u-bottom-nav__icon .a4u-nav-item__brand-icon {
  width: 20px;
  height: 20px;
  margin: 0 auto;
}

/* Sidebar search trigger */
.a4u-sidebar__search {
  margin: 12px 12px 4px;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 12px;
  border-radius: var(--pulse-radius-sm);
  border: 1px solid rgba(255,255,255,0.08);
  background: rgba(255,255,255,0.04);
  color: rgba(255,255,255,0.5);
  font-size: 13px;
  cursor: pointer;
  transition: background var(--pulse-motion-fast) var(--pulse-ease-out);
}

.a4u-sidebar__search:hover {
  background: rgba(255,255,255,0.08);
  color: rgba(255,255,255,0.7);
}

.a4u-sidebar__search-icon {
  width: 16px;
  height: 16px;
  opacity: 0.7;
}

.a4u-sidebar__search-kbd {
  margin-left: auto;
  font-family: var(--pulse-font-mono);
  font-size: 10px;
  padding: 1px 5px;
  border-radius: 3px;
  border: 1px solid rgba(255,255,255,0.12);
  color: rgba(255,255,255,0.4);
}

.a4u-sidebar__nav {
  flex: 1;
  padding: 12px 12px;
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: rgba(255,255,255,0.12) transparent;
}

.a4u-nav-group {
  margin-bottom: 16px;
}

.a4u-nav-group__label {
  margin: 0 12px 6px;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.4);
}

.a4u-nav-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  border-radius: var(--pulse-radius-sm);
  color: rgba(255,255,255,0.65);
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
  margin-bottom: 2px;
  transition: background var(--pulse-motion-fast) var(--pulse-ease-out),
              color var(--pulse-motion-fast) var(--pulse-ease-out);
  border: none;
  background: transparent;
  width: 100%;
  text-align: left;
  font-family: inherit;
  cursor: pointer;
}

.a4u-nav-item:hover {
  background: rgba(255,255,255,0.06);
  color: #f4f5f6;
  text-decoration: none;
}

.a4u-nav-item--active {
  background: var(--pulse-primary-soft);
  color: var(--pulse-primary);
}

.a4u-nav-item--active:hover {
  background: var(--pulse-primary-soft);
  color: var(--pulse-primary);
}

.a4u-nav-item__icon {
  width: 20px;
  text-align: center;
  font-size: 16px;
  opacity: 0.9;
  flex-shrink: 0;
}

/* Session dock in sidebar */
.a4u-sidebar__session-dock {
  margin: 8px 12px;
  padding: 12px;
  border-radius: var(--pulse-radius-md);
  border: 1px solid rgba(255,255,255,0.08);
  background: color-mix(in srgb, var(--pulse-primary) 8%, #111318);
}

.a4u-session-dock__header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}

.a4u-session-dock__status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--pulse-text-subtle);
  flex-shrink: 0;
}

.a4u-session-dock__status-dot--live {
  background: var(--pulse-success);
  box-shadow: 0 0 6px color-mix(in srgb, var(--pulse-success) 50%, transparent);
  animation: pulse-dock-glow 2s ease-in-out infinite;
}

.a4u-session-dock__status-dot--paused {
  background: var(--pulse-warning);
}

@keyframes pulse-dock-glow {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}

.a4u-session-dock__title {
  font-size: 12px;
  font-weight: 650;
  color: #f4f5f6;
}

.a4u-session-dock__meta {
  font-size: 11px;
  color: rgba(255,255,255,0.55);
  margin-bottom: 8px;
  line-height: 1.4;
}

.a4u-session-dock__actions {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.a4u-session-dock__btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  padding: 5px 10px;
  border-radius: var(--pulse-radius-sm);
  border: 1px solid rgba(255,255,255,0.12);
  background: rgba(255,255,255,0.06);
  color: rgba(255,255,255,0.8);
  font-family: var(--pulse-font);
  font-size: 11px;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--pulse-motion-fast) var(--pulse-ease-out);
}

.a4u-session-dock__btn:hover {
  background: rgba(255,255,255,0.12);
  color: #f4f5f6;
}

.a4u-session-dock__btn--stop {
  border-color: color-mix(in srgb, var(--pulse-danger) 40%, transparent);
  color: #fca5a5;
}

.a4u-session-dock__btn--stop:hover {
  background: color-mix(in srgb, var(--pulse-danger) 18%, transparent);
}

.a4u-session-dock__idle {
  font-size: 11px;
  color: rgba(255,255,255,0.4);
  text-align: center;
  padding: 4px 0;
}

/* Sidebar footer / profile */
.a4u-sidebar__footer {
  padding: 12px;
  border-top: 1px solid var(--pulse-sidebar-border);
}

.a4u-sidebar__profile {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px;
  border-radius: var(--pulse-radius-sm);
  transition: background var(--pulse-motion-fast) var(--pulse-ease-out);
  cursor: pointer;
}

.a4u-sidebar__profile:hover {
  background: rgba(255,255,255,0.06);
}

.a4u-sidebar__profile-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--pulse-primary-soft);
  color: var(--pulse-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 12px;
  flex-shrink: 0;
}

.a4u-sidebar__profile-info {
  flex: 1;
  min-width: 0;
}

.a4u-sidebar__profile-name {
  font-size: 13px;
  font-weight: 600;
  color: #f4f5f6;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.a4u-sidebar__profile-role {
  font-size: 11px;
  color: rgba(255,255,255,0.45);
}

.a4u-sidebar__viatone {
  font-size: 11px;
  color: rgba(255,255,255,0.35);
  line-height: 1.5;
  margin-top: 8px;
  padding: 0 8px;
}

.a4u-sidebar__viatone a {
  color: rgba(255,255,255,0.55);
}

.a4u-sidebar__legacy {
  display: block;
  margin-top: 12px;
  font-size: 12px;
  color: rgba(255,255,255,0.35);
}

/* ═══════════════════════════════════════════════════════════════════════
   Main canvas
   ═══════════════════════════════════════════════════════════════════════ */
.a4u-main {
  flex: 1;
  margin-left: var(--pulse-sidebar-w);
  display: flex;
  flex-direction: column;
  min-width: 0;
  background: var(--pulse-bg);
}

.a4u-topbar {
  height: var(--pulse-topbar-h);
  border-bottom: 1px solid var(--pulse-border);
  background: var(--pulse-topbar-bg);
  backdrop-filter: blur(12px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  position: sticky;
  top: 0;
  z-index: 30;
  gap: 16px;
}

.a4u-topbar__left {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.a4u-topbar__menu-btn {
  display: none;
  background: transparent;
  border: 1px solid var(--pulse-border);
  color: var(--pulse-text);
  width: 40px;
  height: 40px;
  border-radius: var(--pulse-radius-sm);
  cursor: pointer;
  font-size: 18px;
  align-items: center;
  justify-content: center;
  padding: 0;
  line-height: 0;
}

.a4u-topbar__menu-btn:focus-visible {
  box-shadow: var(--pulse-focus);
  outline: none;
}

.a4u-topbar__menu-icon {
  display: block;
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  pointer-events: none;
}

.a4u-topbar__title {
  font-size: 15px;
  font-weight: 600;
  color: var(--pulse-text-secondary);
}

.a4u-topbar__center {
  flex: 1;
  display: flex;
  justify-content: center;
  min-width: 0;
}

.a4u-topbar__search {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  min-width: min(100%, 320px);
  max-width: 420px;
  border-radius: var(--pulse-radius-sm);
  border: 1px solid var(--pulse-border);
  background: var(--pulse-input-bg);
  color: var(--pulse-text-muted);
  font-size: 13px;
  cursor: pointer;
  transition: border-color var(--pulse-motion-fast) var(--pulse-ease-out);
}

.a4u-topbar__search:hover {
  border-color: var(--pulse-border-strong);
}

.a4u-topbar__search-icon {
  width: 16px;
  height: 16px;
  opacity: 0.6;
}

.a4u-topbar__search-text {
  flex: 1;
}

.a4u-topbar__search-kbd {
  font-family: var(--pulse-font-mono);
  font-size: 11px;
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid var(--pulse-border);
  color: var(--pulse-text-subtle);
}

.a4u-topbar__right {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.a4u-profile-chip {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 6px 12px 6px 6px;
  border-radius: var(--pulse-radius-full);
  border: 1px solid var(--pulse-border);
  background: var(--pulse-surface);
  font-size: 13px;
  max-width: 220px;
}

.a4u-profile-chip__avatar {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: var(--pulse-primary-soft);
  color: var(--pulse-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 12px;
  flex-shrink: 0;
}

.a4u-profile-chip__email {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: var(--pulse-text-secondary);
}

.a4u-page {
  flex: 1;
  padding: 28px 24px calc(var(--pulse-bottom-nav-h) + 28px);
  max-width: var(--pulse-content-max);
  width: 100%;
  margin: 0 auto;
}

/* ═══════════════════════════════════════════════════════════════════════
   Bottom nav (mobile)
   ═══════════════════════════════════════════════════════════════════════ */
.a4u-bottom-nav {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: var(--pulse-bottom-nav-h);
  background: var(--pulse-bg-elevated);
  border-top: 1px solid var(--pulse-border);
  z-index: 50;
  padding: 0 8px;
  justify-content: space-around;
  align-items: center;
}

.a4u-bottom-nav__item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  font-size: 10px;
  font-weight: 600;
  color: var(--pulse-text-muted);
  text-decoration: none;
  padding: 8px 10px;
  border-radius: var(--pulse-radius-sm);
  min-width: 56px;
}

.a4u-bottom-nav__item:hover {
  color: var(--pulse-text);
  text-decoration: none;
}

.a4u-bottom-nav__item--active {
  color: var(--pulse-primary);
}

.a4u-bottom-nav__icon {
  font-size: 18px;
}

/* Sidebar overlay */
.a4u-sidebar-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  background: var(--pulse-overlay);
  z-index: 35;
  opacity: 0;
  transition: opacity var(--pulse-motion-base) var(--pulse-ease);
}

.a4u-sidebar-backdrop--open {
  display: block;
  opacity: 1;
}

/* ═══════════════════════════════════════════════════════════════════════
   Responsive
   ═══════════════════════════════════════════════════════════════════════ */
@media (max-width: 900px) {
  .a4u-sidebar {
    transform: translateX(-100%);
  }

  .a4u-sidebar--open {
    transform: translateX(0);
  }

  .a4u-main {
    margin-left: 0;
  }

  .a4u-topbar__menu-btn {
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .a4u-topbar__search,
  .a4u-topbar__center {
    display: none;
  }

  .a4u-bottom-nav {
    display: flex;
  }

  .a4u-page {
    padding-bottom: calc(var(--pulse-bottom-nav-h) + 32px);
  }
}

@media (min-width: 901px) {
  .a4u-bottom-nav {
    display: none !important;
  }
}

@media (max-width: 1024px) {
  .a4u-topbar__search {
    min-width: 200px;
  }
}

/* ═══════════════════════════════════════════════════════════════════════
   Account menu (topbar)
   ═══════════════════════════════════════════════════════════════════════ */
.a4u-account-menu {
  position: relative;
}

.a4u-account-menu__btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  max-width: 220px;
  padding: 6px 10px;
  border-radius: var(--pulse-radius-sm);
  border: 1px solid var(--pulse-border);
  background: var(--pulse-surface);
  color: var(--pulse-text);
  font-family: var(--pulse-font);
  font-size: 13px;
  cursor: pointer;
}

.a4u-account-menu__btn:focus-visible {
  box-shadow: var(--pulse-focus);
  outline: none;
}

.a4u-account-menu__panel {
  position: absolute;
  right: 0;
  top: calc(100% + 6px);
  min-width: 200px;
  padding: 8px;
  border-radius: var(--pulse-radius-md);
  border: 1px solid var(--pulse-border);
  background: var(--pulse-surface-raised);
  box-shadow: var(--pulse-shadow-md);
  z-index: 40;
}

.a4u-account-menu__panel[hidden] {
  display: none !important;
}

.a4u-account-menu__panel a,
.a4u-account-menu__panel button {
  display: block;
  width: 100%;
  text-align: left;
  padding: 10px 12px;
  border: 0;
  background: transparent;
  color: var(--pulse-text);
  font-family: var(--pulse-font);
  font-size: 14px;
  text-decoration: none;
  border-radius: var(--pulse-radius-sm);
  cursor: pointer;
}

.a4u-account-menu__panel a:hover,
.a4u-account-menu__panel button:hover {
  background: var(--pulse-surface-hover);
}

.a4u-account-menu__email {
  padding: 8px 12px 10px;
  font-size: 12px;
  color: var(--pulse-text-secondary);
  border-bottom: 1px solid var(--pulse-border);
  margin-bottom: 4px;
  word-break: break-all;
}

@media (max-width: 720px) {
  .a4u-account-menu__btn .a4u-profile-chip__email {
    display: none;
  }
}