:root {
    color-scheme: light;
    /* Claude 标志性的温暖调色板 */
    --bg: #fdfaf6;            /* 主背景色：温暖的纸白色 */
    --surface: #ffffff;
    --surface-solid: #ffffff;
    --surface-soft: #f0eee9;  /* 侧边栏和用户气泡：浅沙色 */
    --surface-muted: #e6e4dd; /* 悬停状态色 */
    --text: #2d2b29;          /* 深炭灰，比纯黑更护眼 */
    --muted: #76736e;
    --faint: #b0ada6;
    --line: #e3e0d8;          /* 极柔和的边框色 */
    --line-strong: #cac7bf;
    --inverse: #2d2b29;       /* 按钮主色调：深色 */
    --inverse-soft: #4a4845;
    --inverse-text: #fdfaf6;
    --danger: #d94b38;
    --danger-soft: #fbece9;
    --code-bg: #1e1d1b;       /* 代码块背景：高级深灰 */
    --shadow: 0 12px 40px rgba(45, 43, 41, 0.06), 0 2px 8px rgba(45, 43, 41, 0.04);
    --soft-shadow: 0 4px 16px rgba(45, 43, 41, 0.03);
    --chat-max: 860px;        /* Claude 适宜阅读的宽度 */
    
    /* 字体栈：引入衬线字体作为点缀 */
    --font-serif: ui-serif, Georgia, Cambria, "Times New Roman", Times, serif;
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif;
}

* {
    box-sizing: border-box;
}

html,
body {
    width: 100%;
    height: 100%;
    min-width: 0;
}

body {
    margin: 0;
    overflow: hidden;
    background: var(--bg);
    color: var(--text);
    font-family: var(--font-sans);
    letter-spacing: -0.01em;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

button,
input,
textarea {
    font: inherit;
}

button {
    cursor: pointer;
}

.hidden {
    display: none !important;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ================= 鉴权页面 (Auth) ================= */
.auth-shell {
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding: 24px;
    background: var(--bg);
}

.auth-panel {
    width: min(400px, 100%);
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 20px;
    box-shadow: var(--shadow);
    padding: 40px 32px;
}

.brand-mark {
    width: 48px;
    height: 48px;
    display: grid;
    place-items: center;
    border-radius: 12px;
    background: var(--surface-soft);
    color: var(--text);
    font-family: var(--font-serif);
    font-size: 20px;
    font-weight: 500;
    border: 1px solid var(--line);
}

.auth-panel h1 {
    margin: 24px 0 6px;
    font-size: 28px;
    font-family: var(--font-serif);
    font-weight: 400;
}

.auth-copy {
    margin: 0 0 32px;
    color: var(--muted);
    font-size: 15px;
}

.auth-form {
    display: grid;
    gap: 16px;
}

.auth-form label {
    display: grid;
    gap: 8px;
    color: var(--text);
    font-size: 14px;
    font-weight: 500;
}

.auth-form input,
.composer textarea {
    width: 100%;
    border: 1px solid var(--line);
    color: var(--text);
    background: transparent;
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.auth-form input {
    border-radius: 12px;
    padding: 12px 14px;
}

.auth-form input:focus {
    border-color: var(--line-strong);
    box-shadow: 0 0 0 3px rgba(45, 43, 41, 0.05);
}

.composer textarea:focus {
    box-shadow: none;
}

.auth-actions {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-top: 8px;
}

.primary-button,
.secondary-button,
.new-chat-button,
.ghost-button,
.send-button,
.icon-button,
.model-picker-button {
    min-height: 42px;
    border: 1px solid transparent;
    border-radius: 12px;
    padding: 0 16px;
    font-weight: 500;
    transition: all 0.16s ease;
}

.primary-button,
.send-button {
    background: var(--inverse);
    color: var(--inverse-text);
}

.primary-button:hover,
.send-button:hover {
    background: var(--inverse-soft);
}

.secondary-button,
.ghost-button,
.icon-button {
    background: transparent;
    border-color: var(--line);
    color: var(--text);
}

.secondary-button:hover,
.ghost-button:hover,
.icon-button:hover {
    background: var(--surface-muted);
}

.form-error {
    min-height: 20px;
    margin: 0;
    color: var(--danger);
    font-size: 14px;
}

/* ================= 布局框架 ================= */
.app-shell {
    width: 100%;
    height: 100vh;
    min-width: 0;
    min-height: 0;
    display: grid;
    grid-template-columns: 280px minmax(0, 1fr);
    overflow: hidden;
    transition: grid-template-columns 0.2s ease;
}

.app-shell.sidebar-collapsed {
    grid-template-columns: 0 minmax(0, 1fr);
}

/* ================= 侧边栏 (Sidebar - 修改为 Claude 的浅色调) ================= */
.sidebar {
    min-width: 0;
    width: 280px;
    overflow: hidden;
    background: var(--surface-soft); /* 浅沙色背景 */
    color: var(--text);
    display: grid;
    grid-template-rows: auto minmax(0, 1fr) auto;
    border-right: 1px solid var(--line);
    transition: transform 0.2s ease, opacity 0.2s ease, visibility 0.2s ease;
}

.app-shell.sidebar-collapsed .sidebar {
    border-right: 0;
    opacity: 0;
    visibility: hidden;
    transform: translateX(-105%);
    pointer-events: none;
}

.sidebar-header,
.sidebar-footer {
    padding: 16px;
}

.sidebar-header {
    display: flex;
    gap: 10px;
    align-items: center;
}

.new-chat-button {
    width: 100%;
    background: transparent;
    border-color: var(--line);
    color: var(--text);
    box-shadow: 0 1px 2px rgba(0,0,0,0.02);
}

.new-chat-button:hover {
    background: var(--surface-muted);
}

.conversation-list {
    min-height: 0;
    overflow-y: auto;
    padding: 0 12px;
}

.conversation-item {
    width: 100%;
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 4px;
    border: 1px solid transparent;
    border-radius: 10px;
    color: var(--text);
    margin-bottom: 2px;
}

.conversation-item:hover {
    background: var(--surface-muted);
}

.conversation-item.active {
    background: #ffffff; /* 激活项凸显为纯白 */
    border-color: var(--line);
    box-shadow: var(--soft-shadow);
    font-weight: 500;
}

.conversation-select {
    min-width: 0;
    display: grid;
    gap: 4px;
    text-align: left;
    background: transparent;
    color: inherit;
    border: 0;
    padding: 10px 12px;
}

.conversation-title {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    font-size: 14px;
}

.conversation-meta {
    color: var(--muted);
    font-size: 12px;
}

.conversation-actions {
    display: flex;
    gap: 2px;
    padding-right: 7px;
    opacity: 0;
    transition: opacity 0.16s ease;
}

.conversation-item:hover .conversation-actions,
.conversation-item:focus-within .conversation-actions {
    opacity: 1;
}

.conversation-actions button {
    width: 28px;
    height: 28px;
    display: grid;
    place-items: center;
    border: 0;
    border-radius: 6px;
    background: transparent;
    color: var(--muted);
}

.conversation-actions button:hover {
    background: var(--line);
    color: var(--text);
}

.sidebar-footer {
    display: grid;
    gap: 10px;
}

.user-badge {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    color: var(--text);
    font-size: 14px;
    font-weight: 500;
    padding: 0 6px;
}

/* ================= 聊天主体区域 ================= */
.chat-shell {
    min-width: 0;
    min-height: 0;
    height: 100vh;
    display: grid;
    grid-template-rows: auto minmax(0, 1fr) auto;
}

.topbar {
    min-height: 56px;
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 20px;
    background: transparent; /* 极简透明导航栏 */
}

.topbar .icon-button {
    border: none;
    background: transparent;
    padding: 0 8px;
}

.topbar-title {
    min-width: 0;
    display: grid;
    gap: 2px;
}

.topbar-title strong {
    font-size: 15px;
    font-weight: 500;
}

.topbar-title span {
    color: var(--muted);
    font-size: 12px;
}

.chat-stage {
    min-height: 0;
    position: relative;
    display: grid;
}

.messages {
    min-width: 0;
    min-height: 0;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 32px clamp(20px, 5vw, 60px);
}

.messages-inner {
    width: min(var(--chat-max), 100%);
    margin: 0 auto;
    display: grid;
    gap: 32px; /* Claude 风格间距较大，提升阅读体验 */
}

/* ================= 空白页欢迎区 ================= */
.empty-state {
    position: absolute;
    inset: 0;
    z-index: 1;
    display: grid;
    align-content: center;
    justify-items: center;
    text-align: center;
    color: var(--text);
    padding: 32px;
    pointer-events: none;
}

.empty-state h2 {
    margin: 0 0 12px;
    font-family: var(--font-serif);
    font-size: 36px;
    font-weight: 400;
    letter-spacing: -0.02em;
}

.empty-state p {
    margin: 0;
    color: var(--muted);
    font-size: 15px;
}

/* ================= 消息流 (极简纸张风格) ================= */
.message {
    width: 100%;
    display: flex;
    align-items: flex-start;
    gap: 16px;
    min-width: 0;
}

.message.user {
    justify-content: flex-end;
}

.message.assistant {
    justify-content: flex-start;
}

/* Claude 中通常隐藏用户头像，仅展示柔和的气泡 */
.message.user .avatar {
    display: none; 
}

.message.assistant .avatar {
    flex: 0 0 32px;
    width: 32px;
    height: 32px;
    display: grid;
    place-items: center;
    border-radius: 8px; /* 偏方形圆角 */
    background: transparent;
    border: 1px solid var(--line-strong);
    color: var(--text);
    font-family: var(--font-serif);
    font-size: 14px;
}

.message-body {
    min-width: 0;
    max-width: min(900px, calc(100% - 48px));
    max-inline-size: min(900px, calc(100% - 48px));
}

.message.user .message-body {
    max-width: min(720px, 100%);
    max-inline-size: min(720px, 100%);
    overflow: hidden;
}

.message-meta {
    display: flex;
    gap: 8px;
    align-items: center;
    margin-bottom: 6px;
    color: var(--faint);
    font-size: 12px;
    opacity: 0; /* 默认隐藏时间，鼠标悬浮显示 */
    transition: opacity 0.2s;
}

.message:hover .message-meta {
    opacity: 1;
}

.message.user .message-meta {
    justify-content: flex-end;
}

.message-content {
    min-width: 0;
    max-inline-size: 100%;
    overflow-wrap: anywhere;
    word-break: break-word;
    line-height: 1.65;
    font-size: 15px;
}

/* 用户气泡：不突兀的浅卡其色，无阴影 */
.message.user .message-content {
    background: var(--surface-soft);
    color: var(--text);
    border-radius: 20px;
    padding: 14px 20px;
    white-space: pre-wrap;
    border: 1px solid rgba(0,0,0,0.02);
}

/* AI 内容：透明背景，纯文本质感 */
.message.assistant .message-content {
    background: transparent;
    border: none;
    border-radius: 0;
    padding: 4px 0 0 0; 
    box-shadow: none;
}

.message.assistant .message-content.is-empty {
    display: none;
}

.message-attachments {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 8px;
    justify-content: flex-end;
}

.message-attachments span {
    max-width: 240px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    border: 1px solid var(--line);
    border-radius: 999px;
    padding: 4px 10px;
    background: var(--surface);
    color: var(--text);
    font-size: 12px;
}

/* ================= Markdown 排版 ================= */
.markdown-body > :first-child {
    margin-top: 0;
}

.markdown-body > :last-child {
    margin-bottom: 0;
}

.markdown-body p,
.markdown-body ul,
.markdown-body ol,
.markdown-body blockquote,
.markdown-body table,
.markdown-body .katex-display,
.markdown-body .code-block {
    margin: 0 0 16px;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3 {
    margin: 32px 0 16px;
    line-height: 1.3;
    font-weight: 600;
}

.markdown-body h1 { font-size: 24px; }
.markdown-body h2 { font-size: 20px; }
.markdown-body h3 { font-size: 17px; }

.markdown-body ul,
.markdown-body ol {
    padding-left: 24px;
}

.markdown-body li + li {
    margin-top: 6px;
}

.markdown-body blockquote {
    border-left: 3px solid var(--line-strong);
    padding: 2px 0 2px 16px;
    color: var(--muted);
    font-style: italic;
}

.markdown-body code {
    border-radius: 6px;
    background: var(--surface-soft);
    border: 1px solid var(--line);
    padding: 2px 6px;
    font-size: 0.88em;
    font-family: "Cascadia Code", "SFMono-Regular", Consolas, monospace;
}

/* ================= 代码块 (深色质感) ================= */
.code-block {
    max-width: 100%;
    overflow: hidden;
    border: 1px solid var(--line);
    border-radius: 12px;
    background: var(--code-bg);
}

.code-block-toolbar {
    min-height: 38px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 6px 12px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    background: rgba(255, 255, 255, 0.03);
    color: var(--faint);
    font-size: 12px;
}

.copy-code-button {
    min-height: 26px;
    border: none;
    border-radius: 6px;
    background: transparent;
    color: var(--faint);
    padding: 0 8px;
}

.copy-code-button:hover {
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
}

.markdown-body pre {
    max-width: 100%;
    overflow-x: auto;
    margin: 0;
    background: transparent;
    color: #e6e3da;
    padding: 16px;
}

.markdown-body pre code {
    background: transparent;
    border: none;
    padding: 0;
    color: inherit;
}

.markdown-body table {
    width: 100%;
    border-collapse: collapse;
    display: block;
    overflow-x: auto;
}

.markdown-body th,
.markdown-body td {
    border: 1px solid var(--line);
    padding: 10px 14px;
    text-align: left;
}

.markdown-body th {
    background: var(--surface-soft);
    font-weight: 500;
}

.markdown-body .katex-display {
    overflow-x: auto;
    overflow-y: hidden;
    padding: 4px 0;
}

.math-fallback {
    font-family: "Cascadia Code", Consolas, monospace;
}

/* 思维链/推理区域 */
.reasoning-panel {
    margin: 0 0 12px;
    border: none;
    border-left: 2px solid var(--line);
    background: transparent;
    color: var(--muted);
    font-size: 14px;
    line-height: 1.6;
}

.reasoning-panel summary {
    list-style: none;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 4px 0 4px 12px;
    color: var(--muted);
    cursor: pointer;
    user-select: none;
    font-weight: 500;
}

.reasoning-panel summary::-webkit-details-marker {
    display: none;
}

.reasoning-panel summary::after {
    content: "展开推理";
    color: var(--faint);
    font-size: 12px;
    font-weight: normal;
}

.reasoning-panel[open] summary::after {
    content: "收起";
}

.reasoning-text {
    padding: 8px 0 12px 12px;
    white-space: pre-wrap;
    overflow-wrap: anywhere;
}

/* ================= 底部输入区域 (Composer - 整合式胶囊设计) ================= */
.composer {
    background: linear-gradient(180deg, transparent 0%, var(--bg) 25%);
    border-top: none;
    padding: 12px clamp(20px, 5vw, 60px) 32px;
}

/* 将 inner 变为一个完整的白色背景块，容纳内部所有元素 */
.composer-inner {
    width: min(var(--chat-max), 100%);
    min-width: 0;
    margin: 0 auto;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 24px;
    box-shadow: var(--shadow);
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto;
    gap: 8px;
    align-items: end;
    padding: 8px 10px; /* 内部安全边距 */
    transition: box-shadow 0.2s, border-color 0.2s;
}

.composer-inner:focus-within {
    border-color: var(--line-strong);
    box-shadow: 0 16px 50px rgba(45, 43, 41, 0.08);
}

.model-picker {
    position: relative;
    padding-bottom: 2px;
}

/* 模型选择按钮变为内部组件 */
.model-picker-button {
    width: 38px;
    min-width: 38px;
    height: 38px;
    min-height: 38px;
    display: grid;
    place-items: center;
    border-radius: 10px;
    padding: 0;
    background: transparent;
    border: none;
    color: var(--text);
    box-shadow: none;
}

.model-picker-button:hover {
    background: var(--surface-soft);
}

.model-logo-image {
    width: 22px;
    height: 22px;
    display: block;
    border-radius: 6px;
}

.model-picker-popover {
    position: absolute;
    left: 0;
    bottom: calc(100% + 16px);
    z-index: 30;
    width: min(280px, calc(100vw - 32px));
    padding: 8px;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 16px;
    box-shadow: var(--shadow);
}

.model-picker-header {
    display: grid;
    gap: 2px;
    padding: 8px 10px 12px;
}

.model-picker-header strong {
    font-size: 14px;
    font-weight: 500;
}

.model-picker-header span {
    color: var(--muted);
    font-size: 12px;
}

.model-options {
    display: grid;
    gap: 2px;
}

.model-option {
    width: 100%;
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 10px;
    text-align: left;
    border: none;
    border-radius: 10px;
    background: transparent;
    padding: 10px 12px;
    color: var(--text);
    font-size: 14px;
}

.model-option:hover,
.model-option.active {
    background: var(--surface-soft);
}

.model-option span {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.model-option-check {
    width: 18px;
    min-width: 18px;
    color: var(--text);
    text-align: center;
}

/* 去除输入框的背景，让它融入外部胶囊容器 */
.composer-input {
    min-width: 0;
    border: none;
    border-radius: 0;
    background: transparent;
    box-shadow: none;
    overflow: hidden;
    padding: 0;
}

.composer textarea {
    max-height: 240px;
    min-height: 44px;
    resize: none;
    border: 0;
    border-radius: 0;
    padding: 10px 8px;
    line-height: 1.5;
    background: transparent;
    font-size: 15px;
}

.composer-after-input {
    display: flex;
    align-items: end;
    gap: 6px;
    min-width: 0;
    padding-bottom: 2px;
}

.attach-button {
    width: 38px;
    min-width: 38px;
    height: 38px;
    min-height: 38px;
    border-radius: 10px;
    border: none;
    padding: 0;
    display: grid;
    place-items: center;
    font-size: 20px;
    background: transparent;
    color: var(--muted);
}

.attach-button:hover {
    background: var(--surface-soft);
    color: var(--text);
}

.attachment-list {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    padding: 6px 8px 0;
}

.attachment-chip {
    max-width: min(280px, 100%);
    display: inline-flex;
    align-items: center;
    gap: 6px;
    border: 1px solid var(--line);
    border-radius: 10px;
    background: var(--surface);
    padding: 4px 6px 4px 10px;
    color: var(--text);
    font-size: 13px;
    box-shadow: var(--soft-shadow);
}

.attachment-chip span {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.attachment-chip button {
    width: 22px;
    height: 22px;
    display: grid;
    place-items: center;
    border: 0;
    border-radius: 6px;
    background: transparent;
    color: var(--muted);
}

.attachment-chip button:hover {
    background: var(--surface-muted);
    color: var(--text);
}

.send-button {
    width: 38px;
    min-width: 38px;
    height: 38px;
    min-height: 38px;
    border-radius: 10px;
    padding: 0;
    display: grid;
    place-items: center;
    font-size: 18px;
    margin-right: 2px;
}

.send-button:disabled,
.new-chat-button:disabled,
.attach-button:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.mobile-only {
    display: none;
}

.desktop-only {
    display: inline-grid;
    place-items: center;
}

.sidebar-overlay {
    display: none;
}

/* ================= 响应式调整 (Mobile) ================= */
@media (max-width: 820px) {
    html,
    body {
        overflow: hidden;
    }

    .app-shell,
    .app-shell.sidebar-collapsed {
        grid-template-columns: minmax(0, 1fr);
    }

    .sidebar {
        position: fixed;
        inset: 0 auto 0 0;
        width: min(86vw, 320px);
        max-width: calc(100vw - 28px);
        z-index: 20;
        transform: translateX(-100%);
        transition: transform 0.2s ease;
    }

    .app-shell.sidebar-collapsed .sidebar {
        border-right: 1px solid var(--line);
        opacity: 1;
        visibility: visible;
        transform: translateX(-100%);
        pointer-events: auto;
    }

    .app-shell.sidebar-collapsed .sidebar.open,
    .sidebar.open {
        transform: translateX(0);
        opacity: 1;
        visibility: visible;
        pointer-events: auto;
    }

    .sidebar-overlay.show {
        display: block;
        position: fixed;
        inset: 0;
        z-index: 10;
        background: rgba(45, 43, 41, 0.2); /* 更温和的半透明黑遮罩 */
    }

    .mobile-only {
        display: inline-grid;
        place-items: center;
    }

    .desktop-only {
        display: none;
    }

    .topbar {
        min-height: 52px;
        padding: 8px 12px;
        border-bottom: 1px solid var(--line);
        background: var(--bg);
    }

    .topbar-title span {
        display: none;
    }

    .messages {
        padding: 24px 16px;
    }

    .messages-inner {
        gap: 24px;
    }

    .empty-state {
        padding: 24px;
    }

    .empty-state h2 {
        font-size: 28px;
    }

    .message {
        gap: 12px;
    }

    .message.assistant .avatar {
        flex-basis: 28px;
        width: 28px;
        height: 28px;
        border-radius: 6px;
        font-size: 12px;
    }

    .message-body,
    .message.user .message-body {
        max-width: calc(100% - 40px);
    }

    .message.assistant .message-content,
    .message.user .message-content {
        padding: 12px 16px;
    }

    .message.assistant .message-content {
        padding: 2px 0 0 0; /* AI文本恢复贴边 */
    }

    .message-meta {
        margin-bottom: 5px;
    }

    .composer {
        padding: 8px 12px 16px;
    }

    .composer-inner {
        grid-template-columns: auto minmax(0, 1fr) auto;
        gap: 6px;
        border-radius: 20px;
        padding: 6px 8px;
    }

    .model-picker-button {
        width: 36px;
        min-width: 36px;
        height: 36px;
        min-height: 36px;
    }

    .model-logo-image {
        width: 20px;
        height: 20px;
    }

    .model-picker-popover {
        left: 0;
        bottom: calc(100% + 12px);
        width: min(320px, calc(100vw - 20px));
    }

    .attach-button,
    .send-button {
        width: 36px;
        min-width: 36px;
        height: 36px;
        min-height: 36px;
    }

    .composer-after-input {
        gap: 4px;
    }

    .composer textarea {
        min-height: 40px;
        padding: 8px 6px;
    }
}

@media (max-width: 520px) {
    .auth-shell {
        padding: 16px;
    }

    .auth-panel {
        padding: 28px 24px;
    }

    .composer-inner {
        grid-template-columns: auto minmax(0, 1fr) auto;
    }

    .model-picker-popover {
        position: fixed;
        left: 10px;
        right: 10px;
        bottom: 80px;
        width: auto;
    }

    /* 极小屏幕下隐藏AI头像以节约空间 */
    .message.assistant .avatar {
        display: none;
    }

    .message.assistant .message-body {
        max-width: 100%;
    }
}