body, html {
  height: 100%;
  min-height: 100vh;
  width: 100vw;
  margin: 0;
  padding: 0;
  font-family: "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: linear-gradient(135deg, #43cea2 0%, #9717ec 100%);
  background-size: cover;
  background-repeat: no-repeat;
  background-attachment: fixed;
}
.msg a, .msg-right a, .msg-left a {
  background-image: linear-gradient(90deg, #f09f08 0%, #c93b03 100%);
  color: transparent;
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-decoration: underline;
  font-weight: bold;
  transition: background .2s;
}
.upload-progress-bar {
  width: 100%;
  height: 8px;
  background: #eee;
  border-radius: 4px;
  margin-top: 8px;
  overflow: hidden;
  position: relative;
}
.upload-progress-inner {
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, #43cea2 0%, #9717ec 100%);
  border-radius: 4px;
  transition: width 0.2s;
}

/* ========= 追加：扩大到平板/大屏手机的纵向自适应与可滚动支持 (宽度 761px~1024px) ========= */
@media (max-width:1024px) and (min-width:761px) {
  html, body {
    height:100%;
    background:#fff;
  }
  /* 取消桌面限定宽度与固定高度结构，改为与手机类似的弹性布局 */
  #chat-app {
    max-width:none;
    margin:0;
    border-radius:0;
    box-shadow:none;
    padding:10px 14px 14px;
    height:100vh;
    display:flex;
    flex-direction:column;
    box-sizing:border-box;
  }
  header {
    flex-shrink:0;
    position:sticky;
    top:0;
    background:#fff;
    z-index:100;
    padding:8px 6px;
    border-bottom:1px solid #e5e5e5;
  }
  #main-container {
    flex:1;
    display:flex;
    flex-direction:row;
    min-height:0;
    gap:14px;
  }
  #sidebar {
    width:240px;
    flex:0 0 240px;
    border-right:1px solid #ddd;
    background:#f7f7f7;
    padding:10px 12px 12px;
    box-sizing:border-box;
    overflow-y:auto;
  }
  #chat-box {
    flex:1;
    min-width:0;
    padding:0 4px 0 4px;
    display:flex;
    flex-direction:column;
    min-height:0;
  }
  /* 去掉桌面端的固定 300px 高度，改为弹性占满 */
#messages {
  overflow-y: auto;
  padding: 12px 0 12px 0;
  min-height: 100px;
  max-height: 42vh;
  background: #fff;
  border-radius: 8px;
  box-shadow: 0 2px 12px #0001;
  margin-bottom: 8px;
}
  #input-area {
    position:sticky;
    bottom:0;
    background:#fff;
    padding:8px 0 8px;
    border-top:1px solid #ddd;
    display:flex;
    gap:8px;
    flex-shrink:0;
    z-index:50;
  }
  #msg-input { flex:1; min-width:0; }
  #input-area button { flex:0 0 80px; }

  /* 调整水印字号略小以避免超出 */
  #messages.watermark .wm-line {
    font-size:20px;
    letter-spacing:3px;
  }
}
.centered {
  width: 30vw;
  min-width: 320px;
  max-width: 420px;
  height: auto;
  margin: 8vh auto 0 auto;
  background: linear-gradient(135deg, #43cea2 0%, #9717ec 100%);
  border-radius: 18px;
  box-shadow: 0 8px 32px rgba(30,60,120,0.18);
  padding: 38px 28px 32px;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(30,60,120,0.18);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  box-sizing: border-box;
}
@media (max-width: 760px) {
  .centered {
    width: 100vw;
    height: 100vh;
    min-width: 0;
    margin: 0;
    border-radius: 0;
    padding: 0;
    box-sizing: border-box;
    max-width: 100vw;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
  }
}
.login-header-center {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 100%;
}
.login-logo {
  width: 72px;
  height: 72px;
  margin-bottom: 18px;
  border-radius: 16px;
  box-shadow: 0 2px 12px rgba(30,60,120,0.12);
  object-fit: contain;
  background: #fff;
}
.lang-switch {
  display: flex;
  gap: 12px;
  margin-bottom: 18px;
}
.lang-switch button {
  background: #1976d2;
  color: #fff;
  border: none;
  border-radius: 6px;
  padding: 6px 16px;
  font-size: 15px;
  cursor: pointer;
  font-weight: 500;
  box-shadow: 0 2px 8px rgba(30,60,120,0.08);
  transition: background .2s;
}
.lang-switch button.active,
.lang-switch button:hover {
  background: #1565c0;
}
.login-title {
  font-size: 22px;
  font-weight: 700;
  color: #1565c0;
  margin-bottom: 16px;
  letter-spacing: 1px;
  text-align: center;
}
#login-msg {
  color: #e0e0e0;
  font-size: 15px;
  text-align: center;
  margin-top: 8px;
}
#chat-app {
  max-width: 900px;
  margin: 30px auto;
  background: #fff;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  padding: 20px;
  height: 100vh;
  display: flex;
  flex-direction: column;
  box-sizing: border-box;
}
#main-container {
  display: flex;
  flex-direction: row;
  flex: 1;
  min-height: 0;
  height: auto;
}
#sidebar {
  width: 220px;
  border-right: 1px solid #eee;
  padding-right: 10px;
  background: #f5f5f5;
  overflow-y: auto;
}
#sidebar button,
#sidebar a {
  background: #3276a6 !important;
}
#chat-box {
  flex: 1;
  padding-left: 20px;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  position: relative;
}
#chat-box.disabled {
  opacity: 0.6;
  pointer-events: none;
  background: #e0e0e0;
}
#chat-list .friend, #chat-list .group {
  padding: 6px 10px;
  cursor: pointer;
  border-radius: 4px;
  margin-bottom: 4px;
  background: #fff;
  transition: all .2s;
  user-select: none;
}
#chat-list .friend:hover, #chat-list .group:hover {
  background: #e8f5e9;
}
#chat-list .friend.active, #chat-list .group.active {
  background: linear-gradient(135deg, #43cea2 0%, #9717ec 100%);
  color: #fff;
  font-weight: bold;
  box-shadow: 0 0 0 1px #a4a4a4af inset;
}
#chat-list .group.unread {
  background: linear-gradient(-45deg,#ecc8ba,#ff7550);
  color:#fff;
  font-weight:bold;
  box-shadow:0 0 0 1px #ece8e8 inset;
  animation: unreadBlink 1s linear infinite;
}
#chat-list .group.unread.active {
  background: linear-gradient(90deg,#1aad19,#34c759);
  box-shadow:0 0 0 1px #1aad19 inset;
}
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
  text-align: center;
  position: relative;
}
header > span {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  display: inline-flex;
  align-items: center;
}
.logout-btn {
  margin-left: auto !important;
}
#messages {
  flex: 1;
  min-height: 0;
  max-height: none;
  overflow-y: scroll !important;
  border: 1px solid #eee;
  border-radius: 6px;
  padding: 10px 10px 90px 10px;
  background: #f7f7f7;
  margin-bottom: 10px;
  -webkit-overflow-scrolling: touch !important;
  overscroll-behavior: contain;
  scrollbar-gutter: stable;
  scrollbar-width: none; /* 隐藏Firefox滚动条 */
  touch-action: pan-y !important;
}
/* 隐藏Chrome/Safari滚动条 */
#messages::-webkit-scrollbar {
  display: none;
}
/* 自定义滚动条 - WebKit */
#messages::-webkit-scrollbar {
  width: 10px;
}
#messages::-webkit-scrollbar-track {
  background: #ececec;
  border-radius: 6px;
}
#messages::-webkit-scrollbar-thumb {
  background: #c1c1c1;
  border-radius: 6px;
}
#messages::-webkit-scrollbar-thumb:hover {
  background: #a5a5a5;
}
.msg {
  background: #9eea6a;
  padding: 8px 12px;
  border-radius: 6px;
  margin-bottom: 8px;
  max-width: 70%;
  word-break: break-all;
  font-family: "Segoe UI", "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.7;
}
.msg-timestamp {
  font-size: 10px;
  color: #5c5959;
  display: block;
  margin-top: 2px;
  margin-left: 0;
  text-align: right;
}
.msg-left .msg-timestamp {
  text-align: left;
}
.msg-left {
  background: #f7f7f7;
  color: #333;
  text-align: left;
  margin-right: auto;
}
.msg .msg-username {
  font-weight: bold;
  color: #04595c;
  margin-right: 4px;
}
.msg-right {
  background: none;
  font-weight: bold;
  color: #222;
  text-align: right;
  margin-left: auto;
  background-clip: text;
  -webkit-background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
  background-image: linear-gradient(90deg, #f09ada 0%, #3909aa 100%);
}
.msg .msg-username {
  font-weight: bold !important;
  color: #1976d2;
  margin-left: 4px;
}
#input-area {
  display: flex;
  gap: 8px;
  width: 100%;
  box-sizing: border-box;
  position: sticky;
  bottom: 0;
  background: #fff;
  padding: 8px 0 8px;
  border-top: 1px solid #ddd;
  flex-shrink: 0;
  z-index: 50;
}
#msg-input { flex:1; width:auto; }
#input-area button { flex:0 0 70px; }
input[type="text"], input[type="password"] {
  width: 100%;
  padding: 8px;
  margin-bottom: 10px;
  border-radius: 4px;
  border: 1px solid #ccc;
  background: transparent;
  color: #222;
}
input[type="text"]::placeholder,
input[type="password"]::placeholder {
  color: #fff;
  opacity: 1;
}
button {
  background: #1aad19;
  color: #fff;
  border: none;
  border-radius: 4px;
  padding: 8px 16px;
  cursor: pointer;
}
button:hover {
  background: #179b16;
}

/* 未读闪烁动画 */
@keyframes unreadBlink {
  0%,100% { filter: brightness(1); }
  50% { filter: brightness(1.35); }
}

/* 群成员管理覆盖层 */
#group-manage-overlay {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 380px;
  max-width: 96vw;
  max-height: 92vh;
  background: #e3f2fd;
  backdrop-filter: blur(2px);
  -webkit-backdrop-filter: blur(2px);
  z-index: 12;
  display: flex;
  flex-direction: column;
  padding: 18px 18px 16px;
  border: 1px solid #e2e2e2;
  border-radius: 14px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.13);
  animation: fadeIn .18s ease;
  overflow: hidden;
}

/* 手机端弹窗全屏显示，防止被 sidebar 遮盖 */
@media (max-width: 760px) {
  #group-manage-overlay {
    position: fixed !important;
    top: 0 !important;
    left: 0 !important;
    right: 0 !important;
    bottom: 0 !important;
    width: 100vw !important;
    height: 100vh !important;
    max-width: 100vw !important;
    max-height: 100vh !important;
    z-index: 9999 !important;
    border-radius: 0 !important;
    box-shadow: none !important;
    padding: 0 !important;
    display: block !important;
    flex-direction: column !important;
    align-items: center !important;
    justify-content: center !important;
    background: #e3f2fd !important;
    visibility: visible !important;
    opacity: 1 !important;
    overflow: auto !important;
  }
  #group-manage-overlay > .overlay-header,
  #group-manage-overlay > .owner-line,
  #group-manage-overlay > .member-list,
  #group-manage-overlay > .add-member,
  #group-manage-overlay > .group-danger {
    margin: 0 auto !important;
    max-width: 380px !important;
    width: 96vw !important;
    background: #fff !important;
    border-radius: 12px !important;
    box-shadow: 0 2px 12px #0001 !important;
  }
}
#group-manage-overlay .overlay-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-weight: 600;
  font-size: 15px;
  margin-bottom: 6px;
  color: #222;
}
#group-manage-overlay .overlay-header .close-btn {
  background: #ff4d4f;
  padding: 2px 9px;
  font-size: 16px;
  line-height: 1;
  border-radius: 4px;
}
#group-manage-overlay .overlay-header .close-btn:hover {
  background: #e04445;
}
#group-manage-overlay .owner-line {
  font-size: 13px;
  color: #555;
  margin-bottom: 6px;
}
#group-manage-overlay .member-list {
  flex: 1;
  overflow-y: auto;
  border: 1px solid #eee;
  border-radius: 6px;
  padding: 8px 10px;
  background: #fafafa;
  margin-bottom: 10px;
  max-height: 220px;
}
#group-manage-overlay .member-list ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
#group-manage-overlay .member-list li {
  padding: 4px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 13px;
  border-bottom: 1px dashed #e3e3e3;
}
#group-manage-overlay .member-list li:last-child {
  border-bottom: none;
}
#group-manage-overlay .kick-member-btn {
  background: #ff3b30;
  padding: 2px 8px;
  font-size: 12px;
  border-radius: 4px;
}
#group-manage-overlay .kick-member-btn:hover {
  background: #e23329;
}
#group-manage-overlay .add-member {
  display: flex;
  gap: 6px;
  margin-top: 4px;
}
#group-manage-overlay .add-member input {
  flex: 1;
  margin: 0;
}
#group-manage-overlay .add-member button {
  white-space: nowrap;
}
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* 新建群聊覆盖层 */
#group-create-overlay {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 380px;
  max-width: 96vw;
  max-height: 92vh;
  background: #e3f2fd;
  backdrop-filter: blur(2px);
  -webkit-backdrop-filter: blur(2px);
  z-index: 11;
  display: flex;
  flex-direction: column;
  padding: 18px 18px 16px;
  border: 1px solid #e2e2e2;
  border-radius: 14px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.13);
  animation: fadeIn .18s ease;
  overflow: hidden;
}

/* 手机端弹窗全屏显示，防止被 sidebar 遮盖 */
@media (max-width: 760px) {
  #group-create-overlay {
    position: fixed !important;
    top: 0 !important;
    left: 0 !important;
    right: 0 !important;
    bottom: 0 !important;
    width: 100vw !important;
    height: 100vh !important;
    max-width: 100vw !important;
    max-height: 100vh !important;
    z-index: 9999 !important;
    border-radius: 0 !important;
    box-shadow: none !important;
    padding: 0 !important;
    display: block !important;
    flex-direction: column !important;
    align-items: center !important;
    justify-content: center !important;
    background: #e3f2fd !important;
    visibility: visible !important;
    opacity: 1 !important;
    overflow: auto !important;
  }
  #group-create-overlay > .overlay-header,
  #group-create-overlay > .create-body,
  #group-create-overlay > .create-actions {
    margin: 0 auto !important;
    max-width: 380px !important;
    width: 96vw !important;
    background: #fff !important;
    border-radius: 12px !important;
    box-shadow: 0 2px 12px #0001 !important;
  }
}
#group-create-overlay .overlay-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-weight: 600;
  font-size: 15px;
  margin-bottom: 8px;
  color: #222;
}
#group-create-overlay .overlay-header .close-btn {
  background: #ff4d4f;
  padding: 2px 9px;
  font-size: 16px;
  line-height: 1;
  border-radius: 4px;
}
#group-create-overlay .overlay-header .close-btn:hover {
  background: #e04445;
}
#group-create-overlay .create-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  min-height: 0;
}
#group-create-overlay #group-name {
  padding: 8px;
  border: 1px solid #ccc;
  border-radius: 4px;
  margin-bottom: 8px;
  font-size: 14px;
}
#group-create-overlay .member-select-title {
  font-size: 13px;
  color: #555;
  margin-bottom: 4px;
}
#group-create-overlay .member-select-list {
  flex: 1;
  overflow-y: auto;
  border: 1px solid #eee;
  background: #fafafa;
  border-radius: 6px;
  padding: 8px 10px;
  display: grid;
  grid-template-columns: repeat(auto-fill,minmax(90px,1fr));
  gap: 6px 10px;
  margin-bottom: 10px;
  max-height: 220px;
}
#group-create-overlay .member-option {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 12px;
  background: #fff;
  border: 1px solid #e5e5e5;
  border-radius: 4px;
  padding: 4px 6px;
  cursor: pointer;
  user-select: none;
}
#group-create-overlay .member-option:hover {
  border-color: #1aad19;
  background: #f1fff1;
}
#group-create-overlay .member-option input {
  margin: 0;
}
#group-create-overlay .empty {
  font-size: 12px;
  color: #888;
  grid-column: 1 / -1;
  text-align: center;
  padding: 12px 0;
}
#group-create-overlay .create-actions {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
}
#group-create-overlay .create-actions button {
  padding: 6px 18px;
  font-size: 14px;
}
#group-create-overlay .create-actions .secondary-btn {
  background: #888;
}
#group-create-overlay .create-actions .secondary-btn:hover {
  background: #666;
}

/* 群主标记 */
.owner-badge {
  display: inline-block;
  color: #ffb300;
  font-size: 12px;
  line-height: 1;
  vertical-align: middle;
  text-shadow: 0 0 2px rgba(0,0,0,0.25);
  margin-left: 2px;
}

/* 解散群危险操作区域 */
.group-danger {
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px dashed #e3e3e3;
  display: flex;
  justify-content: flex-start;
}

.danger-btn {
  background: #ff3b30;
  font-weight: 600;
  letter-spacing: 1px;
  box-shadow: 0 2px 4px rgba(255,59,48,0.3);
}
.danger-btn:hover {
  background: #e23329;
}

/* 系统消息样式 */
#messages .sys-msg {
  text-align: center;
  font-size: 12px;
  color: #666;
  padding: 6px 10px;
  margin: 8px auto;
  background: #f0f0f0;
  border-radius: 12px;
  width: fit-content;
  max-width: 80%;
  box-shadow: inset 0 0 0 1px #e2e2e2;
  font-style: italic;
}

/* 兼容未读状态与 owner 标记：未读时 owner 星标保持高亮 */
#chat-list .group.unread .owner-badge {
  filter: drop-shadow(0 0 2px rgba(0,0,0,0.4)) brightness(1.15);
}

/* 聊天窗口水印（用户名 45 度 多行） */
#messages.watermark {
  position: relative;
  overflow: hidden;
}
#messages.watermark::before { content: none; }
#messages.watermark .wm-line {
  position: absolute;
  left: 50%;
  transform: translateX(-50%) rotate(-45deg);
  font-size: 64px;
  font-weight: 700;
  letter-spacing: 4px;
  color: rgba(0,0,0,0.05);
  pointer-events: none;
  user-select: none;
  white-space: nowrap;
  text-transform: uppercase;
  font-family: "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  mix-blend-mode: multiply;
}

/* 回到底部按钮 */
#scroll-bottom-btn {
  position: absolute;
  right: 12px;
  bottom: 110px;
  background: #1aad19;
  color: #fff;
  border: none;
  padding: 6px 12px;
  border-radius: 20px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.15);
  cursor: pointer;
  font-size: 13px;
  line-height: 1;
  z-index: 60;
  transition: background .2s;
}
#scroll-bottom-btn:hover {
  background:#179b16;
}
#scroll-bottom-btn.hidden {
  display:none;
}
.hidden { display:none !important; }

/* 输入区按钮与输入框分两行布局优化 */
.input-tools-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 4px;
}
#input-area {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* ================== 移动端适配与侧栏抽屉 ================== */
#sidebar-mask {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.35);
  display: none;
  z-index: 80;
}

body.sidebar-open #sidebar-mask {
  display: block;
}

@media (max-width: 760px) {
  header {
    justify-content: center !important;
    text-align: center !important;
    display: flex !important;
    align-items: center !important;
  }
  .logout-btn {
    margin-left: auto !important;
  }
  #mobile-back-btn {
    display: none;
    position: absolute;
    top: 12px;
    left: 12px;
    z-index: 100;
    background: none;
    border: none;
    padding: 6px;
    border-radius: 50%;
    width: 38px;
    height: 38px;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    transition: background 0.2s;
  }
  #mobile-back-btn[style*="inline-flex"] {
    display: inline-flex !important;
  }
  #mobile-back-btn svg {
    width: 28px;
    height: 28px;
  }

  html, body {
    height:100%;
    overflow:hidden;
    background:#fff;
  }
  .centered {
    width: 100vw;
    height: 100vh;
    min-width: 0;
    margin: 0;
    border-radius: 0;
    padding: 0;
    box-sizing: border-box;
    max-width: 100vw;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
  }
  #chat-app {
    max-width:none;
    margin:0;
    border-radius:0;
    box-shadow:none;
    padding:0 10px 10px;
    height:100vh;
    display:flex;
    flex-direction:column;
  }
  header {
    flex-shrink:0;
    position:sticky;
    top:0;
    background:#fff;
    z-index:100;
    padding:6px 4px;
    border-bottom:1px solid #e5e5e5;
  }
  #main-container {
    flex:1;
    display:flex;
    flex-direction:column;
    min-height:0;
    position:relative;
  }
  #sidebar {
    position:fixed;
    top:0;
    bottom:0;
    left:0;
    width:100vw;
    max-width:100vw;
    background:#f5f5f5;
    padding:70px 14px 14px 14px;
    box-shadow:none;
    transform:none;
    transition:none;
    z-index:90;
    border-right:none;
    overflow-y:auto;
  }
  #sidebar-toggle { display:none !important; }
  #sidebar h3 { margin-top:0; }

  #chat-box {
    padding:0;
    margin:0;
    flex:1;
    min-height:0;
    display:flex;
    flex-direction:column;
  }
  #messages {
    flex:1;
    min-height:0;
    max-height:none;
    overflow-y:auto;
    margin-bottom:6px;
    /* 预留底部输入栏与安全区高度，避免最后几条被 sticky 输入框遮挡 */
    padding-bottom: calc(72px + env(safe-area-inset-bottom, 0px));
    -webkit-overflow-scrolling: touch;
    overscroll-behavior: contain;
  }
  #input-area {
    position:sticky;
    bottom:0;
    background:#fff;
    padding:6px 0 6px;
    flex-shrink:0;
    display:flex;
    gap:6px;
    width:100%;
    box-sizing:border-box;
    border-top:1px solid #ddd;
    z-index:120;
  }
  #msg-input {
    flex:1;
    min-width:0;
  }
  #input-area button {
    flex:0 0 64px;
  }
  /* 未选中会话（chat-box 为 disabled）时，手机端隐藏底部输入框 */
  #chat-box.disabled #input-area {
    display: none !important;
  }

  /* 汉堡按钮样式 */
  #sidebar-toggle {
    background:#5c7fa3;
    color:#fff;
    border-radius:6px;
    padding:6px 12px;
    font-size:18px;
    line-height:1;
    box-shadow:0 2px 6px rgba(92,127,163,0.18);
  }
  #sidebar-toggle:active { transform:scale(.94); }

  /* 列表滚动优化 */
  #chat-list {
    max-height:none;
    overflow-y:auto;
  }

  /* 水印在窄屏减小字号 */
  #messages.watermark .wm-line {
    font-size:54px;
    letter-spacing:3px;
  }
}
@media (max-width: 760px) {
  #group-manage-overlay, #group-create-overlay {
    position: fixed !important;
    top: 0 !important;
    left: 0 !important;
    right: 0 !important;
    bottom: 0 !important;
    width: 100vw !important;
    height: 100vh !important;
    z-index: 99999 !important;
    display: flex !important;
    flex-direction: column !important;
    align-items: center !important;
    justify-content: center !important;
    background: #e3f2fd !important;
    visibility: visible !important;
    opacity: 1 !important;
    overflow: auto !important;
  }
  #group-manage-overlay > *, #group-create-overlay > * {
    max-width: 96vw !important;
    width: 96vw !important;
    background: #fff !important;
    border-radius: 12px !important;
    box-shadow: 0 2px 12px #0001 !important;
    margin: auto !important;
    display: flex !important;
    flex-direction: column !important;
    align-items: center !important;
    justify-content: center !important;
    min-height: 40vh !important;
  }
}