html,
body {
  width: 100vw;
  height: 100vh;
  margin: 0;
  padding: 0;
  overflow: hidden;
}

.sidebar {
  height: 100vh;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 1040;
  box-shadow: 2px 0 12px rgba(0, 0, 0, 0.08);
  background: #fafafa;
  display: flex !important;
}

.sidebar .fw-semibold {
  font-size: 1.08rem;
}

.sidebar .btn-outline-light {
  border-width: 2px;
  font-weight: 500;
  transition: background 0.15s, color 0.15s;
  background: #0f172a;
  color: #fff;
}

.sidebar .btn-outline-light:hover,
.sidebar .btn-outline-light:focus {
  background: #0f172a;
  color: #fff;
}

.toggle-sidebar-btn {
  border: none;
  outline: none;
}

.header button:active,
.header button:focus {
  border: none;
  outline: none;
}

@media (max-width: 991.98px) {
  .sidebar {
    position: fixed;
    transform: translateX(-100%);
    box-shadow: 2px 0 16px rgba(0, 0, 0, 0.18);
  }
  .sidebar.active {
    transform: translateX(0);
  }
  .chat-container {
    padding-left: 0 !important;
  }
  #openSidebar {
    display: block !important;
  }
}

#openSidebar {
  display: none;
  transition: box-shadow 0.2s;
}

#openSidebar:active {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.18);
}

.chat-container {
  height: 100vh;
  display: flex;
  flex-direction: column;
  background: #f8f9fa;
}

.chat-messages {
  background: #f8f9fa;
  overflow-y: auto;
  flex: 1 1 auto;
  scroll-behavior: smooth;
}

/* Message bubble animation */
.animate__animated {
  --animate-duration: 0.5s;
}

/* Hide scrollbars for chat list/messages on Webkit */
.chat-messages::-webkit-scrollbar,
#chatList::-webkit-scrollbar {
  width: 6px;
  background: transparent;
}
.chat-messages::-webkit-scrollbar-thumb,
#chatList::-webkit-scrollbar-thumb {
  background: #dee2e6;
  border-radius: 3px;
}

/* Responsive fix for input area */
@media (max-width: 575.98px) {
  .chat-container .px-4 {
    padding-left: 0.5rem !important;
    padding-right: 0.5rem !important;
  }
  .chat-messages > .d-flex > div {
    max-width: 90vw !important;
    font-size: 1rem;
    padding: 0.75rem 1rem;
    word-break: break-word;
  }
  .chat-messages {
    padding-left: 0.25rem !important;
    padding-right: 0.25rem !important;
  }
  #chatInput {
    font-size: 1rem;
    padding: 0.5rem 1rem;
  }
}

.sidebar-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.35);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s;
  z-index: 1039;
}
.sidebar.active ~ .sidebar-backdrop {
  opacity: 1;
  pointer-events: auto;
}

.chat-session-item {
  border-radius: 8px;
  transition: background 0.15s;
  border: none !important;
}
.chat-session-item:hover,
.chat-session-item.active {
  background: #f5f8ff !important;
  color: #000;
}
.chat-session-title {
  font-weight: 600;
  color: #3f3f46;
  font-size: 0.9rem !important;
  line-height: 1.2;
}
.chat-session-lastmsg {
  color: #6c757d;
  font-size: 0.8rem;
  line-height: 1.1;
  max-width: 200px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.fa-message {
  font-size: 0.9rem;
  margin-top: 0.85rem;
}

.btn-trash {
  display: none;
  background: transparent;
  border: none;
  border-radius: 6px;
  color: #dc3545;
  transition: background 0.15s, color 0.15s;
  outline: none;
  box-shadow: none;
}
.btn-trash i {
  color: #dc3545;
  font-size: 0.9rem;
  margin-top: 0.6rem;
}
.btn-trash:hover,
.btn-trash:focus {
  background: #ffeaea;
  border: none;
  outline: none;
}
.btn-trash:hover i,
.btn-trash:focus i {
  color: #b91c1c;
}