/* === Strato Layout === */

#app {
  height: 100vh;
  width: 100vw;
  overflow: hidden;
}

/* === 3-Column Chat Layout === */
#view-chat {
  display: grid;
  grid-template-columns: var(--sidebar-width) var(--session-list-width) 1fr;
  grid-template-rows: 1fr;
  height: 100vh;
  background: var(--bg-primary);
}

#sidebar {
  grid-column: 1;
  background: var(--bg-secondary);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 12px 0;
  gap: 4px;
  z-index: 3;
}

#session-list-panel {
  grid-column: 2;
  background: var(--bg-primary);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  z-index: 2;
}

#chat-area {
  grid-column: 3;
  display: flex;
  flex-direction: column;
  background: var(--bg-primary);
  overflow: hidden;
  z-index: 1;
}

/* === Settings View === */
#view-settings {
  height: 100vh;
  overflow-y: auto;
  background: var(--bg-primary);
}

.settings-container {
  max-width: 640px;
  margin: 0 auto;
  padding: 24px;
}

/* === Admin View === */
#view-admin {
  height: 100vh;
  overflow-y: auto;
  background: var(--bg-primary);
}

.admin-container {
  max-width: 960px;
  margin: 0 auto;
  padding: 24px;
}

.btn-back {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-primary);
  padding: 8px 20px;
  border-radius: var(--radius);
  font-size: var(--font-size-sm);
  margin-bottom: 24px;
  transition: background var(--transition);
}
.btn-back:hover { background: var(--hover); }

/* === Responsive (mobile) === */
@media (max-width: 768px) {
  :root {
    --sidebar-width: 48px;
    --session-list-width: 100%;
  }
  #view-chat {
    grid-template-columns: var(--sidebar-width) 0 1fr;
  }
  #session-list-panel.hidden { display: none !important; }
  #session-list-panel:not(.hidden) {
    position: absolute;
    left: var(--sidebar-width);
    width: calc(100vw - var(--sidebar-width));
    height: 100vh;
    z-index: 10;
  }
}