/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: #f8fafc;
    height: 100vh;
    margin: 0;
    padding: 0;
    overflow: hidden;
}

/* 登录注册界面样式 */
.auth-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 20px;
}

.auth-box {
    width: 100%;
    max-width: 400px;
    background: rgba(255, 255, 255, 0.95);
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
}

/* 移动端优化：避免底部被系统条或键盘遮挡，并稍微上移内容 */
@media (max-width: 480px) {
    .auth-container {
        align-items: flex-start;
        padding-top: max(32px, calc(20px + env(safe-area-inset-top, 0px)));
        padding-bottom: max(48px, calc(24px + env(safe-area-inset-bottom, 0px)));
    }
    .auth-box {
        margin-top: 12px;
    }
}

.auth-logo {
    text-align: center;
    margin-bottom: 20px;
    color: #667eea;
}

.auth-box h2 {
    color: #2d3748;
    font-size: 24px;
    margin-bottom: 10px;
    text-align: center;
    font-weight: 600;
}

.auth-desc {
    text-align: center;
    color: #718096;
    margin-bottom: 30px;
    font-size: 14px;
}

.auth-form {
    margin-bottom: 24px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #4a5568;
    font-size: 14px;
    font-weight: 500;
}

.auth-container .input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.auth-container .input-wrapper svg {
    position: absolute;
    left: 12px;
    color: #718096;
}

.auth-container .input-wrapper input {
    width: 100%;
    padding: 12px 16px 12px 40px;
    border: 2px solid #e2e8f0;
    border-radius: 10px;
    font-size: 15px;
    transition: all 0.3s ease;
    background: #ffffff;
    color: #2d3748;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.auth-container .input-wrapper input:hover {
    border-color: #cbd5e0;
}

.auth-container .input-wrapper input:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
    outline: none;
}

.auth-container .input-wrapper input::placeholder {
    color: #a0aec0;
}

.btn-primary {
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 10px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.2);
}

.btn-primary svg {
    transition: transform 0.2s ease;
}

.btn-primary:hover svg {
    transform: translateX(4px);
}

.auth-footer {
    text-align: center;
    border-top: 1px solid #e2e8f0;
    padding-top: 20px;
    margin-top: 20px;
}

.auth-link {
    color: #718096;
    font-size: 14px;
}

.auth-link a {
    color: #667eea;
    text-decoration: none;
    font-weight: 500;
}

.auth-link a:hover {
    text-decoration: underline;
}

.alert {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 14px;
}

.alert-error {
    background: #fff5f5;
    color: #c53030;
    border: 1px solid #feb2b2;
}

.alert svg {
    color: currentColor;
}
/* 聊天界面布局 */
.chat-container {
    display: flex;
    width: 100vw;
    height: 100vh;
    background: #f8fafc;
    overflow: hidden;
}

/* 用户列表样式 */
.users-list {
    width: 280px;
    background: #fff;
    border-right: 1px solid #e2e8f0;
    display: flex;
    flex-direction: column;
    box-shadow: 2px 0 8px rgba(0, 0, 0, 0.05);
}

.users-header {
    padding: 20px;
    background: #f8fafc;
    border-bottom: 1px solid #e2e8f0;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.header-content h3 {
    color: #2d3748;
    font-size: 18px;
    font-weight: 600;
}

.online-count {
    font-size: 12px;
    color: #718096;
    background: #edf2ff;
    padding: 4px 8px;
    border-radius: 12px;
}

.search-box {
    position: relative;
    margin-top: 10px;
}

.search-box svg {
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    color: #a0aec0;
}

.search-box input {
    width: 100%;
    padding: 10px 16px 10px 40px;
    border: 1px solid #e2e8f0;
    border-radius: 10px;
    background: white;
    font-size: 14px;
    transition: all 0.2s ease;
}

.search-box input:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
    outline: none;
}

.users-content {
    flex: 1;
    overflow-y: auto;
    padding: 10px 0;
}

.section-header {
    padding: 16px 20px 8px;
    color: #64748b;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    display: flex;
    align-items: center;
    gap: 8px;
}

.user-item {
    display: flex;
    align-items: center;
    padding: 12px 16px;
    margin: 4px 8px;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    gap: 12px;
}

.user-item:hover {
    background: #f3f4f6;
}

.user-item.selected {
    background: #edf2ff;
    border: 1px solid #e0e7ff;
}

.user-item.online {
    background: #f0fdf4;
}

.user-item.online:hover {
    background: #dcfce7;
}

.user-avatar {
    position: relative;
    width: 42px;
    height: 42px;
    border-radius: 12px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    font-weight: 600;
    font-size: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.user-status {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    border: 2px solid #fff;
    position: absolute;
    bottom: -2px;
    right: -2px;
    background: #cbd5e0;
    transition: background-color 0.3s ease;
}

.online .user-status {
    background: #22c55e;
    box-shadow: 0 0 0 2px #fff;
}

/* 当在线样式直接加在元素自身时也生效 */
.user-status.online {
    background: #22c55e;
    box-shadow: 0 0 0 2px #fff;
}

.user-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.user-email {
    color: #1e293b;
    font-size: 14px;
    font-weight: 500;
}

.user-last-seen {
    color: #64748b;
    font-size: 12px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.online .user-last-seen {
    color: #22c55e;
}

.unread-count {
    min-width: 22px;
    height: 22px;
    padding: 0 6px;
    background: #ef4444;
    color: white;
    border-radius: 11px;
    font-size: 12px;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 4px rgba(239, 68, 68, 0.2);
}
/* 主聊天区域样式 */
.chat-main {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: #fff;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

.chat-header {
    height: 70px;
    padding: 0 24px;
    background: #fff;
    border-bottom: 1px solid #e2e8f0;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.chat-header-info {
    display: flex;
    align-items: center;
    gap: 12px;
}

.admin-info {
    display: flex;
    align-items: center;
    gap: 12px;
}

.user-details {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.user-details h2 {
    color: #2d3748;
    font-size: 16px;
    font-weight: 600;
}

.status-text {
    font-size: 12px;
    color: #48bb78;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.btn-icon {
    padding: 8px;
    border: none;
    background: none;
    color: #718096;
    cursor: pointer;
    border-radius: 8px;
    transition: all 0.2s ease;
}

.btn-icon:hover {
    background: #f7fafc;
    color: #4a5568;
}

.btn-logout {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    border: none;
    background: #f7fafc;
    color: #4a5568;
    font-size: 14px;
    font-weight: 500;
    border-radius: 8px;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.2s ease;
}

.btn-logout:hover {
    background: #edf2ff;
    color: #667eea;
}

/* 消息区域样式 */
.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 20px 0;
    background: #f8fafc;
}

.message {
    display: flex;
    flex-direction: column;
    gap: 4px;
    margin: 16px 0;
    padding: 0 24px;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message-sender {
    font-size: 12px;
    color: #718096;
    padding: 0 16px;
}

.message.sent .message-sender {
    text-align: right;
}

.message.received .message-sender {
    text-align: left;
}

.message-content {
    position: relative;
    padding: 12px 16px;
    border-radius: 16px;
    max-width: 70%;
    font-size: 14px;
    line-height: 1.5;
}

.message.sent .message-content {
    background: linear-gradient(135deg, #5b6ac5 0%, #6b5b95 100%);
    color: white;
    margin-left: auto;
    border-bottom-right-radius: 4px;
}

.message.received .message-content {
    background: linear-gradient(135deg, #3f9eae 0%, #4b89ac 100%);
    color: white;
    margin-right: auto;
    border-bottom-left-radius: 4px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.message-timestamp {
    font-size: 11px;
    color: #a0aec0;
    margin-top: 4px;
}

/* 空聊天提示 */
.chat-empty-hint {
    color: #94a3b8;
    font-size: 14px;
    text-align: center;
    padding: 24px 0;
}

.message.sent .message-timestamp {
    text-align: right;
}

.message.received .message-timestamp {
    text-align: left;
}

/* 图片消息和代码块样式 */
.message-content.image-content,
.message-content:has(.code-block) {
    background: transparent !important;
}

.message-content.image-content img {
    max-width: 300px;
    max-height: 300px;
    width: auto;
    height: auto;
    border-radius: 5px;
    object-fit: contain;
    cursor: pointer;
    transition: transform 0.2s ease;
}

/* 添加电脑端的图片尺寸 */
@media (min-width: 769px) {
    .message-content.image-content img {
        max-width: 500px;    /* 增加到500px */
        max-height: 500px;   /* 增加到500px */
    }
}

.message-content.image-content img:hover {
    transform: scale(1.02);
}

/* 视频消息样式 */
.message-content.video-content {
    padding: 4px;
}

.message-content.video-content video {
    max-width: 300px;
    max-height: 300px;
    width: auto;
    height: auto;
    border-radius: 5px;
    cursor: pointer;
    background: #000;
}

/* 电脑端的视频尺寸 */
@media (min-width: 769px) {
    .message-content.video-content video {
        max-width: 500px;
        max-height: 500px;
    }
}

/* 输入区域样式整合 */
.chat-input-container {
    display: flex;
    flex-direction: column;
    padding: 20px;
    background: #fff;
    border-top: 1px solid #e2e8f0;
}

.chat-buttons {
    display: flex;
    gap: 10px;
    align-items: center;
    margin-bottom: 10px;
}

.action-button {
    display: flex;
    align-items: center;
    gap: 5px;
    padding: 8px 15px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s ease;
    color: white;
}

.action-button svg {
    width: 20px;
    height: 20px;
    stroke: currentColor;
}

/* 按钮颜色样式 */
#upload-button {
    background-color: #4CAF50;
}

#upload-button:hover {
    background-color: #45a049;
}

#code-button {
    background-color: #2196F3;
}

#code-button:hover {
    background-color: #1976D2;
}

#send-button {
    background-color: #FF5722;
}

#send-button:hover {
    background-color: #F4511E;
}

/* 视频上传按钮样式 */
#upload-video-button {
    background-color: #9C27B0;
}

#upload-video-button:hover {
    background-color: #7B1FA2;
}

.action-button:disabled {
    background-color: #cccccc;
    cursor: not-allowed;
    opacity: 0.7;
}

/* 聊天页面的输入框样式 */
.chat-input-container .input-wrapper {
    flex: 1;
    display: flex;
    align-items: flex-end;
    gap: 10px;
    background: #f8fafc;
    border-radius: 12px;
    padding: 8px 12px;
}

.chat-input-container .input-wrapper textarea {
    flex: 1;
    border: none;
    background: none;
    resize: none;
    padding: 8px;
    min-height: 40px;
    max-height: 120px;
    font-size: 14px;
    line-height: 1.5;
    color: #2d3748;
}

.chat-input-container .input-wrapper textarea:focus {
    outline: none;
}

.chat-input-container .input-wrapper textarea::placeholder {
    color: #a0aec0;
}

/* 上传进度条样式 */
.upload-progress {
    padding: 12px;
    background: #f8fafc;
    border-radius: 8px;
}

.progress-text {
    font-size: 12px;
    color: #718096;
    margin-bottom: 8px;
}

.progress-bar {
    height: 4px;
    background: #e2e8f0;
    border-radius: 2px;
    overflow: hidden;
}

.progress-inner {
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    width: 0;
    transition: width 0.3s ease;
}

/* VS Code 风格的代码块 */
.code-block {
    overflow: hidden;
    border-radius: 8px;
    background: #1e1e1e;  /* VS Code 深色背景 */
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 16px;
    background: #252526;  /* VS Code 标题栏颜色 */
    border-bottom: 1px solid #333;
}

.code-language {
    font-size: 12px;
    color: #858585;  /* VS Code 浅灰色文字 */
    font-family: 'Monaco', 'Menlo', monospace;
}

.copy-button {
    padding: 4px 10px;
    font-size: 12px;
    border: 1px solid #454545;
    border-radius: 4px;
    background: #333333;
    color: #cccccc;
    cursor: pointer;
    transition: all 0.2s ease;
}

.copy-button:hover {
    background: #404040;
    border-color: #505050;
}

.code-block pre {
    margin: 0;
    padding: 16px;
    max-height: 300px;
    overflow: auto;
    background: #1e1e1e;
    font-family: 'Monaco', 'Menlo', monospace;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .chat-container {
        flex-direction: column;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        width: 100%;
        height: 100%;
        overflow: hidden;
    }

    .users-list {
        width: 100%;
        height: 100%;
        position: fixed;
        left: 0;
        top: 0;
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        z-index: 1000;
        background: #21252b;
    }

    .users-list.show {
        transform: translateX(0);
    }

    /* 添加切换按钮样式 */
    .toggle-users-list {
        display: block;
        position: fixed;
        left: 10px;
        top: 10px;
        z-index: 1001;
        padding: 8px;
        background: #4b5263;
        border: none;
        border-radius: 4px;
        color: #abb2bf;
        cursor: pointer;
    }

    .chat-main {
        position: relative;
        width: 100%;
        height: 100%;
        display: flex;
        flex-direction: column;
        overflow: hidden;
    }

    .chat-messages {
        flex: 1;
        position: relative;
        height: auto;
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
        padding-bottom: 100px;
    }

    .chat-input-container {
        position: fixed;
        left: 0;
        right: 0;
        bottom: 0;
        width: 100%;
        padding: 10px;
        background: #fff;
        box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.05);
        z-index: 100;
        display: flex;
        align-items: center;
        min-height: 60px;
        max-height: 200px;
    }

    .input-wrapper {
        flex: 1;
        min-height: 40px;
        max-height: 120px;
        background: #f8fafc;
        border-radius: 20px;
        margin: 0 8px;
        padding: 8px 12px;
        display: flex;
        align-items: center;
    }

    #message-input {
        flex: 1;
        min-height: 24px;
        max-height: 100px;
        padding: 6px;
        margin: 0;
        border: none;
        background: none;
        font-size: 16px;
        line-height: 1.4;
        -webkit-appearance: none;
        appearance: none;
    }

    .btn-upload,
    .btn-send {
        flex-shrink: 0;
        width: 40px;
        height: 40px;
        padding: 8px;
        border-radius: 20px;
        display: flex;
        align-items: center;
        justify-content: center;
        -webkit-tap-highlight-color: transparent;
    }

    /* 处理 iOS 底部安全区域 */
    @supports (padding: max(0px)) {
        .chat-input-container {
            padding-bottom: max(10px, env(safe-area-inset-bottom));
        }
    }
}

/* 滚动条样式 */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: #f8fafc;
}

::-webkit-scrollbar-thumb {
    background: #cbd5e0;
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: #a0aec0;
}

/* 用户列表滚动条 */
.users-content::-webkit-scrollbar {
    width: 4px;
}

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

.users-content::-webkit-scrollbar-thumb {
    background: #cbd5e0;
    border-radius: 2px;
}

.users-content::-webkit-scrollbar-thumb:hover {
    background: #94a3b8;
}

/* 删除之前添加的复杂动画，保持简单的过渡效果 */
.user-item {
    transition: all 0.3s ease;
}

.user-status {
    transition: background-color 0.3s ease;
}

.user-item.online {
    transition: background-color 0.3s ease;
}

/* 文件消息样式 */
.message-content.file-content {
    padding: 10px;
}

.file-link {
    display: flex;
    align-items: center;
    gap: 10px;
    color: inherit;
    text-decoration: none;
    padding: 10px;
    background: rgba(0, 0, 0, 0.1);
    border-radius: 5px;
    transition: background 0.2s;
}

.file-link:hover {
    background: rgba(0, 0, 0, 0.2);
}

.file-link svg {
    flex-shrink: 0;
}

.file-link span {
    word-break: break-all;
}

/* 文件上传按钮样式 */
#upload-file-button {
    background-color: #2196F3;
}

#upload-file-button:hover {
    background-color: #1976D2;
}

/* ---- 跟随系统：深色模式（优先针对移动端小屏） ---- */
@media (prefers-color-scheme: dark) {
    @media (max-width: 768px) {
        body { background-color: #0f1115; color: #e5e7eb; }
        .chat-container { background: #0f1115; }
        .users-list { background: #111318; border-right: 1px solid #1f2430; }
        .users-header { background: #0f1115; border-bottom: 1px solid #1f2430; }
        .header-content h3 { color: #e5e7eb; }
        .online-count { color: #9aa4b2; }
        .search-box input { background: #0f1115; color: #e5e7eb; border: 1px solid #1f2430; }
        .section-header { color: #9aa4b2; }
        .user-item { background: transparent; border-bottom: 1px solid #1b2030; }
        .user-item.online { background: rgba(34,197,94,0.08); }
        .user-email { color: #e5e7eb; }
        .user-last-seen { color: #9aa4b2; }
        .chat-main { background: #0b0d12; }
        .chat-messages { background: #0b0d12; }
        .message-content { box-shadow: none; }
        .message.sent .message-content { background: linear-gradient(135deg, #4853a7 0%, #564a7f 100%); }
        .message.received .message-content { background: linear-gradient(135deg, #2d7a86 0%, #36697f 100%); }
        .message-timestamp { color: #8b93a1; }
        .chat-input-container { background: #0f1115; box-shadow: 0 -2px 10px rgba(0,0,0,0.35); }
        .input-wrapper { background: #0b0d12; }
        .auth-container { background: linear-gradient(135deg, #1a1f2b 0%, #1c1a29 100%); }
        .auth-box { background: rgba(22, 24, 32, 0.95); }
        .auth-box h2 { color: #e5e7eb; }
        .auth-desc { color: #9aa4b2; }
        .auth-container .input-wrapper input { background: #111318; color: #e5e7eb; border-color: #242b38; }
        .auth-container .input-wrapper input::placeholder { color: #6b7280; }
        .btn-primary { box-shadow: none; }
        .chat-empty-hint { color: #9aa4b2; }
    }
}

/* 若设备未开启系统深色模式，也在移动端启用同样的深色外观（强制生效） */
@media (max-width: 768px) {
    body.dark-forced .chat-container,
    body.dark-forced { background-color: #0f1115; color: #e5e7eb; }
    body.dark-forced .users-list { background: #111318; border-right: 1px solid #1f2430; }
    body.dark-forced .users-header { background: #0f1115; border-bottom: 1px solid #1f2430; }
    body.dark-forced .header-content h3 { color: #e5e7eb; }
    body.dark-forced .online-count { color: #9aa4b2; }
    body.dark-forced .search-box input { background: #0f1115; color: #e5e7eb; border: 1px solid #1f2430; }
    body.dark-forced .section-header { color: #9aa4b2; }
    body.dark-forced .user-item { background: transparent; border-bottom: 1px solid #1b2030; }
    body.dark-forced .user-item.online { background: rgba(34,197,94,0.08); }
    body.dark-forced .user-email { color: #e5e7eb; }
    body.dark-forced .user-last-seen { color: #9aa4b2; }
    body.dark-forced .chat-main { background: #0b0d12; }
    body.dark-forced .chat-messages { background: #0b0d12; }
    body.dark-forced .message-content { box-shadow: none; }
    body.dark-forced .message.sent .message-content { background: linear-gradient(135deg, #4853a7 0%, #564a7f 100%); }
    body.dark-forced .message.received .message-content { background: linear-gradient(135deg, #2d7a86 0%, #36697f 100%); }
    body.dark-forced .message-timestamp { color: #8b93a1; }
    body.dark-forced .chat-input-container { background: #0f1115; box-shadow: 0 -2px 10px rgba(0,0,0,0.35); }
    body.dark-forced .input-wrapper { background: #0b0d12; }
    body.dark-forced .auth-container { background: linear-gradient(135deg, #1a1f2b 0%, #1c1a29 100%); }
    body.dark-forced .auth-box { background: rgba(22, 24, 32, 0.95); }
    body.dark-forced .auth-box h2 { color: #e5e7eb; }
    body.dark-forced .auth-desc { color: #9aa4b2; }
    body.dark-forced .auth-container .input-wrapper input { background: #111318; color: #e5e7eb; border-color: #242b38; }
    body.dark-forced .auth-container .input-wrapper input::placeholder { color: #6b7280; }
    body.dark-forced .btn-primary { box-shadow: none; }
    body.dark-forced .chat-empty-hint { color: #9aa4b2; }
}

/* ---- 移动端中性色主题（默认） ---- */
@media (max-width: 768px) {
    body { background: #f2f3f5; color: #2d3748; }
    .chat-container { background: #f2f3f5; }
    .users-list { background: #ffffff; border-right: 1px solid #e6eaf1; }
    .users-header { background: #f7f8fb; border-bottom: 1px solid #e6eaf1; }
    .header-content h3 { color: #2d3748; }
    .online-count { color: #64748b; }
    .search-box input { background: #ffffff; color: #2d3748; border: 1px solid #e2e8f0; }
    .section-header { color: #64748b; }
    .user-item { background: transparent; border-bottom: 1px solid #eef2f7; }
    .user-item.online { background: #ecf8f1; }
    .user-email { color: #1f2937; }
    .user-last-seen { color: #6b7280; }
    .chat-main { background: #f7f9fc; }
    .chat-messages { background: #f7f9fc; }
    .message-content { box-shadow: 0 1px 2px rgba(0,0,0,0.04); }
    .message.sent .message-content { background: linear-gradient(135deg, #6a76c8 0%, #7a6aa0 100%); }
    .message.received .message-content { background: linear-gradient(135deg, #4aa8b7 0%, #5b90a9 100%); }
    .message-timestamp { color: #94a3b8; }
    .chat-input-container { background: #ffffff; box-shadow: 0 -2px 10px rgba(0,0,0,0.06); }
    .input-wrapper { background: #f3f5f8; }
}