/* ========================================
   微聊 - 样式设计
   类微信暗色主题风格
   ======================================== */

/* CSS 变量 */
:root {
    /* 颜色 - 暗色主题 */
    --color-bg-dark: #111b21;
    --color-bg-medium: #202c33;
    --color-bg-light: #2a3942;
    --color-bg-hover: #374248;

    --color-primary: #00a884;
    --color-primary-light: #25d366;
    --color-primary-dark: #008f72;

    --color-text-primary: #e9edef;
    --color-text-secondary: #8696a0;
    --color-text-muted: #667781;

    --color-border: #2a3942;
    --color-input-bg: #2a3942;

    --color-message-out: #005c4b;
    --color-message-in: #202c33;

    --color-online: #25d366;
    --color-offline: #667781;

    --color-danger: #ea4335;
    --color-warning: #fbbc05;
    --color-success: #34a853;

    /* 间距 */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 12px;
    --spacing-lg: 16px;
    --spacing-xl: 24px;

    /* 圆角 */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-full: 50%;

    /* 阴影 */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);

    /* 过渡 */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
}

/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--color-bg-dark);
    color: var(--color-text-primary);
    line-height: 1.5;
    min-height: 100vh;
}

a {
    color: var(--color-primary);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

input,
textarea,
button {
    font-family: inherit;
    font-size: inherit;
}

.hidden {
    display: none !important;
}

/* ========================================
   登录/注册页面
   ======================================== */

.auth-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    background: linear-gradient(135deg, var(--color-bg-dark) 0%, #1a2e35 100%);
}

.auth-container {
    width: 100%;
    max-width: 400px;
    padding: var(--spacing-xl);
}

.auth-logo {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.auth-logo .logo-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
    animation: bounce 2s ease-in-out infinite;
}

@keyframes bounce {

    0%,
    100% {
        transform: translateY(0);
    }

    50% {
        transform: translateY(-10px);
    }
}

.auth-logo h1 {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.auth-logo p {
    color: var(--color-text-secondary);
    font-size: 0.9rem;
}

.auth-form {
    background: var(--color-bg-medium);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-lg);
}

.auth-form h2 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xs);
}

.form-group input {
    width: 100%;
    padding: var(--spacing-md);
    background: var(--color-input-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    transition: border-color var(--transition-fast);
}

.form-group input:focus {
    outline: none;
    border-color: var(--color-primary);
}

.form-group input::placeholder {
    color: var(--color-text-muted);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-md);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-primary {
    width: 100%;
    background: var(--color-primary);
    color: white;
}

.btn-primary:hover {
    background: var(--color-primary-dark);
}

.btn-primary:active {
    transform: scale(0.98);
}

.auth-switch {
    text-align: center;
    margin-top: var(--spacing-lg);
    color: var(--color-text-secondary);
    font-size: 0.875rem;
}

.auth-message {
    margin-top: var(--spacing-lg);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    text-align: center;
    font-size: 0.875rem;
}

.auth-message.error {
    background: rgba(234, 67, 53, 0.2);
    color: var(--color-danger);
}

.auth-message.success {
    background: rgba(52, 168, 83, 0.2);
    color: var(--color-success);
}

/* ========================================
   聊天页面
   ======================================== */

.chat-page {
    overflow: hidden;
}

.chat-container {
    display: flex;
    height: 100vh;
}

/* 侧边栏 */
.sidebar {
    width: 350px;
    min-width: 300px;
    background: var(--color-bg-medium);
    border-right: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
}

.user-profile {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    background: var(--color-bg-light);
    border-bottom: 1px solid var(--color-border);
}

.user-avatar {
    width: 44px;
    height: 44px;
    background: var(--color-primary);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

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

.user-name {
    font-weight: 500;
}

.user-status {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.user-status.online::before {
    content: '●';
    color: var(--color-online);
    margin-right: 4px;
}

.btn-icon {
    width: 36px;
    height: 36px;
    background: transparent;
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    font-size: 1.25rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--transition-fast);
}

.btn-icon:hover {
    background: var(--color-bg-hover);
}

.sidebar-actions {
    display: flex;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
}

.search-box {
    flex: 1;
}

.search-box input {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-input-bg);
    border: none;
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
}

.search-box input:focus {
    outline: none;
}

.search-box input::placeholder {
    color: var(--color-text-muted);
}

/* 好友请求 */
.friend-requests {
    padding: var(--spacing-md);
    background: var(--color-bg-light);
    border-bottom: 1px solid var(--color-border);
}

.requests-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-sm);
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

.requests-count {
    background: var(--color-primary);
    color: white;
    padding: 2px 8px;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
}

.requests-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.request-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    background: var(--color-bg-medium);
    border-radius: var(--radius-md);
}

.request-item .avatar {
    width: 36px;
    height: 36px;
    background: var(--color-bg-hover);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
}

.request-item .name {
    flex: 1;
    font-size: 0.875rem;
}

.request-item .btn-accept {
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--color-primary);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    cursor: pointer;
}

/* 联系人列表 */
.contacts-list {
    flex: 1;
    overflow-y: auto;
}

.contacts-list::-webkit-scrollbar {
    width: 6px;
}

.contacts-list::-webkit-scrollbar-thumb {
    background: var(--color-bg-hover);
    border-radius: 3px;
}

.empty-contacts {
    text-align: center;
    padding: var(--spacing-xl) * 2;
    color: var(--color-text-muted);
}

.empty-contacts .empty-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.5;
}

.empty-contacts .hint {
    font-size: 0.875rem;
    margin-top: var(--spacing-sm);
}

.contact-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    cursor: pointer;
    transition: background var(--transition-fast);
    border-bottom: 1px solid var(--color-border);
}

.contact-item:hover {
    background: var(--color-bg-hover);
}

.contact-item.active {
    background: var(--color-bg-light);
}

.contact-avatar {
    position: relative;
    width: 48px;
    height: 48px;
    background: var(--color-bg-hover);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.contact-avatar .status-dot {
    position: absolute;
    bottom: 2px;
    right: 2px;
    width: 12px;
    height: 12px;
    border-radius: var(--radius-full);
    border: 2px solid var(--color-bg-medium);
}

.contact-avatar .status-dot.online {
    background: var(--color-online);
}

.contact-avatar .status-dot.offline {
    background: var(--color-offline);
}

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

.contact-name {
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.contact-last-msg {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.contact-meta {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: var(--spacing-xs);
}

.contact-time {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.unread-badge {
    background: var(--color-primary);
    color: white;
    font-size: 0.75rem;
    padding: 2px 6px;
    border-radius: var(--radius-sm);
    min-width: 20px;
    text-align: center;
}

/* 聊天主区域 */
.chat-main {
    flex: 1 1 0;
    min-height: 0;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    background: var(--color-bg-dark);
    position: relative;
}

.chat-empty {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--color-text-muted);
}

.chat-empty .empty-icon {
    font-size: 5rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.5;
}

.chat-empty h2 {
    margin-bottom: var(--spacing-sm);
}

/* 聊天窗口 */
.chat-window {
    flex: 1 1 0;
    min-height: 0;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.chat-header {
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--color-bg-medium);
    border-bottom: 1px solid var(--color-border);
}

.chat-target {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.target-avatar {
    width: 40px;
    height: 40px;
    background: var(--color-bg-hover);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.target-info {
    display: flex;
    flex-direction: column;
}

.target-name {
    font-weight: 500;
}

.target-status {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.target-status.online {
    color: var(--color-online);
}

/* 消息列表 */
.messages-container {
    flex: 1 1 0;
    min-height: 0;
    overflow-y: auto;
    padding: var(--spacing-lg);
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><rect fill="%23111b21"/><circle cx="20" cy="20" r="2" fill="%23202c33" opacity="0.3"/><circle cx="60" cy="40" r="2" fill="%23202c33" opacity="0.3"/><circle cx="80" cy="80" r="2" fill="%23202c33" opacity="0.3"/></svg>');
}

.messages-container::-webkit-scrollbar {
    width: 6px;
}

.messages-container::-webkit-scrollbar-thumb {
    background: var(--color-bg-hover);
    border-radius: 3px;
}

.messages-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.message {
    max-width: 65%;
    display: flex;
    flex-direction: column;
}

.message.sent {
    align-self: flex-end;
}

.message.received {
    align-self: flex-start;
}

.message-bubble {
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    position: relative;
    word-wrap: break-word;
}

.message.sent .message-bubble {
    background: var(--color-message-out);
    border-bottom-right-radius: var(--spacing-xs);
}

.message.received .message-bubble {
    background: var(--color-message-in);
    border-bottom-left-radius: var(--spacing-xs);
}

.message-text {
    font-size: 0.9375rem;
    line-height: 1.4;
}

.message-time {
    font-size: 0.6875rem;
    color: var(--color-text-muted);
    text-align: right;
    margin-top: var(--spacing-xs);
}

.message.sent .message-time {
    color: rgba(255, 255, 255, 0.6);
}

/* 正在输入 */
.typing-indicator {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

.typing-dots {
    animation: typing 1.5s infinite;
}

@keyframes typing {

    0%,
    100% {
        opacity: 0.3;
    }

    50% {
        opacity: 1;
    }
}

/* 输入区域 */
.message-input {
    display: flex;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--color-bg-medium);
    border-top: 1px solid var(--color-border);
}

.message-input textarea {
    flex: 1;
    padding: var(--spacing-md);
    background: var(--color-input-bg);
    border: none;
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    resize: none;
    max-height: 120px;
}

.message-input textarea:focus {
    outline: none;
}

.message-input textarea::placeholder {
    color: var(--color-text-muted);
}

.btn-send {
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--color-primary);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-weight: 500;
    transition: background var(--transition-fast);
}

.btn-send:hover {
    background: var(--color-primary-dark);
}

/* Modal 弹窗 */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.modal-content {
    width: 90%;
    max-width: 400px;
    background: var(--color-bg-medium);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
}

.modal-header h3 {
    font-size: 1.125rem;
}

.btn-close {
    background: transparent;
    border: none;
    color: var(--color-text-secondary);
    font-size: 1.25rem;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.btn-close:hover {
    color: var(--color-text-primary);
}

.modal-body {
    padding: var(--spacing-lg);
}

.search-results {
    max-height: 300px;
    overflow-y: auto;
}

.search-results .hint {
    text-align: center;
    color: var(--color-text-muted);
    padding: var(--spacing-lg);
}

.search-result-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    transition: background var(--transition-fast);
}

.search-result-item:hover {
    background: var(--color-bg-hover);
}

.search-result-item .avatar {
    width: 40px;
    height: 40px;
    background: var(--color-bg-hover);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.search-result-item .info {
    flex: 1;
}

.search-result-item .name {
    font-weight: 500;
}

.search-result-item .username {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

.search-result-item .btn-add {
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--color-primary);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.875rem;
}

.search-result-item .btn-add:hover {
    background: var(--color-primary-dark);
}

.search-result-item .btn-add:disabled {
    background: var(--color-bg-hover);
    color: var(--color-text-muted);
    cursor: not-allowed;
}

/* Toast */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--color-bg-light);
    color: var(--color-text-primary);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    transition: all var(--transition-normal);
    z-index: 2000;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

.toast-icon {
    font-size: 1.25rem;
}

/* 响应式 */
@media (max-width: 768px) {
    .sidebar {
        width: 280px;
        min-width: 280px;
    }

    .message {
        max-width: 85%;
    }
}

@media (max-width: 600px) {
    .chat-container {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        height: 50%;
    }

    .chat-main {
        height: 50%;
    }
}

/* ========================================
   文件传输样式
   ======================================== */

/* 文件上传按钮 */
.btn-file {
    flex-shrink: 0;
}

/* 上传进度条 */
.upload-progress {
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--color-bg-medium);
    border-top: 1px solid var(--color-border);
}

.progress-bar {
    height: 4px;
    background: var(--color-bg-hover);
    border-radius: 2px;
    overflow: hidden;
    margin-bottom: var(--spacing-xs);
}

.progress-fill {
    height: 100%;
    background: var(--color-primary);
    transition: width 0.3s ease;
}

.progress-text {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

/* 文件消息 */
.file-message {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-sm);
    background: rgba(0, 0, 0, 0.1);
    border-radius: var(--radius-sm);
    min-width: 200px;
}

.file-icon {
    font-size: 2rem;
    flex-shrink: 0;
}

.file-details {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
}

.file-name {
    font-size: 0.875rem;
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.file-size {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.file-download {
    font-size: 1.5rem;
    text-decoration: none;
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
    transition: background var(--transition-fast);
}

.file-download:hover {
    background: rgba(255, 255, 255, 0.1);
    text-decoration: none;
}

/* 图片消息 */
.image-message {
    flex-direction: column;
    padding: 0;
    background: transparent;
}

.image-message img {
    max-width: 280px;
    max-height: 200px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: opacity var(--transition-fast);
}

.image-message img:hover {
    opacity: 0.9;
}

.image-message .file-info {
    display: flex;
    justify-content: space-between;
    padding: var(--spacing-xs) 0;
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

/* ========================================
   群聊样式
   ======================================== */

/* 群头像样式 */
.group-avatar {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%) !important;
}

/* 成员选择列表 */
.member-selection {
    max-height: 250px;
    overflow-y: auto;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm);
}

.member-checkbox {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: background var(--transition-fast);
}

.member-checkbox:hover {
    background: var(--color-bg-hover);
}

.member-checkbox input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--color-primary);
}

.member-avatar {
    width: 32px;
    height: 32px;
    background: var(--color-bg-hover);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
}

.member-name {
    font-size: 0.9rem;
}

/* 群消息发送者名称 */
.message-sender {
    font-size: 0.75rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
}

/* 创建群聊弹窗表单 */
#createGroupModal .form-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    color: var(--color-text-secondary);
    font-size: 0.875rem;
}

#createGroupModal .btn-primary {
    margin-top: var(--spacing-md);
}

/* Message Recall Styles */

/* 撤回按钮 */
.btn-recall {
    display: none;
    margin-top: 4px;
    padding: 2px 8px;
    background: rgba(0, 0, 0, 0.6);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.7rem;
    cursor: pointer;
    white-space: nowrap;
}

.message.sent .message-bubble:hover .btn-recall {
    display: inline-block;
}

.btn-recall:hover {
    background: rgba(0, 0, 0, 0.8);
}

/* 消息气泡需要相对定位 */
.message-bubble {
    position: relative;
}

/* 已撤回消息 */
.recalled-text {
    color: var(--color-text-muted);
    font-style: italic;
    font-size: 0.85rem;
}

/* Message Recall Styles */
.btn-recall {
    display: none;
    margin-top: 4px;
    padding: 2px 8px;
    background: rgba(0, 0, 0, 0.4);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.7rem;
    cursor: pointer;
    white-space: nowrap;
}

.message.sent .message-bubble:hover .btn-recall {
    display: inline-block;
}

.btn-recall:hover {
    background: rgba(0, 0, 0, 0.7);
}

.message-bubble {
    position: relative;
}

.recalled-text {
    color: var(--color-text-muted);
    font-style: italic;
    font-size: 0.85rem;
}

/* File Helper Styles */
.file-helper-avatar {
    background: linear-gradient(135deg, #4CAF50 0%, #2E7D32 100%) !important;
}

.contact-item.file-helper {
    border-bottom: 1px solid var(--color-border);
}

.message.sent .btn-recall {
    display: inline-block !important;
}

/* Screenshot and Input Styles */
.message-input {
    display: flex;
    align-items: flex-end;
    padding: 16px;
    background: var(--color-bg-medium);
    border-top: 1px solid var(--color-border);
    gap: 8px;
}

.message-input .btn-icon {
    background: none;
    border: none;
    font-size: 1.25rem;
    cursor: pointer;
    padding: 8px;
    border-radius: 4px;
    transition: background-color 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-primary);
}

.message-input .btn-icon:hover {
    background-color: var(--color-bg-hover);
}

/* ========================================
   移动端响应式布局
   ======================================== */

/* 返回按钮 - 默认隐藏 */
.btn-back {
    display: none;
    background: transparent;
    border: none;
    color: var(--color-text-primary);
    font-size: 1.5rem;
    cursor: pointer;
    padding: var(--spacing-sm);
    margin-right: var(--spacing-sm);
    border-radius: var(--radius-full);
    transition: background var(--transition-fast);
}

.btn-back:hover {
    background: var(--color-bg-hover);
}

/* 768px 以下为移动端 */
@media screen and (max-width: 768px) {

    /* 默认显示侧边栏，隐藏聊天区 */
    .sidebar {
        width: 100%;
        min-width: 100%;
    }

    .chat-main {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        z-index: 100;
        background: var(--color-bg-dark);
        flex-direction: column;
    }

    /* 当有 chat-active 类时，显示聊天区，隐藏侧边栏 */
    .chat-container.chat-active .sidebar {
        display: none !important;
    }

    .chat-container.chat-active .chat-main {
        display: flex !important;
        flex-direction: column !important;
    }

    /* 聊天窗口占满整个 chat-main */
    .chat-container.chat-active .chat-window {
        display: flex !important;
        flex-direction: column !important;
        flex: 1 !important;
        height: 100% !important;
        min-height: 0 !important;
        overflow: hidden !important;
    }

    /* 显示返回按钮 */
    .btn-back {
        display: flex !important;
        align-items: center;
        justify-content: center;
    }

    /* 聊天头部固定在顶部 */
    .chat-header {
        display: flex;
        align-items: center;
        padding: var(--spacing-md);
        flex-shrink: 0 !important;
        flex-grow: 0 !important;
    }

    .chat-target {
        flex: 1;
    }

    /* 消息区域占满剩余空间，可滚动 */
    .messages-container {
        flex: 1 1 0 !important;
        overflow-y: auto !important;
        min-height: 0 !important;
        max-height: none !important;
    }

    /* 输入区域固定在底部 */
    .message-input {
        flex-shrink: 0 !important;
        flex-grow: 0 !important;
        position: relative !important;
        bottom: 0 !important;
        left: 0 !important;
        right: 0 !important;
        padding: var(--spacing-sm) var(--spacing-md) !important;
        padding-bottom: max(var(--spacing-sm), env(safe-area-inset-bottom)) !important;
        background: var(--color-bg-medium) !important;
        border-top: 1px solid var(--color-border) !important;
    }

    .message-input textarea {
        padding: var(--spacing-sm);
    }

    /* 隐藏聊天空状态（因为移动端默认在联系人列表） */
    .chat-empty {
        display: none !important;
    }

    /* 用户信息紧凑 */
    .user-profile {
        padding: var(--spacing-md);
    }

    /* 联系人选项更大易于触摸 */
    .contact-item {
        padding: var(--spacing-lg);
    }

    /* 上传进度条固定位置 */
    .upload-progress {
        flex-shrink: 0;
    }
}