:root {
    --bg: #FFFFFF;
    --fg: #111111;
    --muted: #6B7280;
    --muted-light: #9CA3AF;
    --accent: #111111;
    --card: #F8F9FA;
    --card-hover: #F3F4F6;
    --border: #E5E7EB;
    --border-light: #F3F4F6;
    --user-bubble: #111111;
    --user-bubble-text: #FFFFFF;
    --separator: rgba(0,0,0,0.04);
    --input-bg: #FFFFFF;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.06);
    --shadow-lg: 0 12px 40px rgba(0,0,0,0.10);
    --shadow-xl: 0 24px 60px rgba(0,0,0,0.12);
    --radius-sm: 12px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --transition-fast: 0.15s cubic-bezier(0.16, 1, 0.3, 1);
    --transition-base: 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    --transition-slow: 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

[data-theme="dark"] {
    --bg: #0A0A0A;
    --fg: #F5F5F5;
    --muted: #9CA3AF;
    --muted-light: #6B7280;
    --accent: #F5F5F5;
    --card: #141414;
    --card-hover: #1A1A1A;
    --border: #1F1F1F;
    --border-light: #2A2A2A;
    --user-bubble: #F5F5F5;
    --user-bubble-text: #0A0A0A;
    --separator: rgba(255,255,255,0.04);
    --input-bg: #141414;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.20);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.30);
    --shadow-lg: 0 12px 40px rgba(0,0,0,0.40);
    --shadow-xl: 0 24px 60px rgba(0,0,0,0.50);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

html, body {
    height: 100%;
    width: 100%;
    overflow: hidden;
    background: var(--bg);
    transition: background-color var(--transition-slow);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
    color: var(--fg);
    overscroll-behavior: none;
    -webkit-font-smoothing: antialiased;
}

.chat-container {
    height: 100%;
    height: 100dvh;
    display: flex;
    flex-direction: column;
    width: 100%;
    overflow: hidden;
}

/* ========== Toast ========== */
.toast-container {
    position: fixed;
    top: max(20px, env(safe-area-inset-top));
    left: 50%;
    transform: translateX(-50%);
    z-index: 300;
    display: flex;
    flex-direction: column;
    gap: 8px;
    pointer-events: none;
}
.toast {
    background: var(--fg);
    color: var(--bg);
    padding: 10px 20px;
    border-radius: 100px;
    font-size: 14px;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    transform: translateY(-10px) scale(0.96);
    transition: all var(--transition-base);
    pointer-events: auto;
    white-space: nowrap;
    letter-spacing: 0.2px;
}
.toast.show {
    opacity: 1;
    transform: translateY(0) scale(1);
}

/* ========== 侧边栏 ========== */
.sidebar-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.20);
    z-index: 199;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-base), visibility var(--transition-base);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}
.sidebar-overlay.active {
    opacity: 1;
    visibility: visible;
}

.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: 320px;
    height: 100%;
    height: 100dvh;
    background: var(--bg);
    border-right: 1px solid var(--border);
    z-index: 200;
    transform: translateX(-100%);
    transition: transform var(--transition-slow);
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-xl);
}
.sidebar.active {
    transform: translateX(0);
}

.sidebar-header {
    padding: 20px 16px;
    padding-top: max(20px, env(safe-area-inset-top));
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-shrink: 0;
}

.sidebar-title {
    font-size: 15px;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 8px;
    letter-spacing: -0.2px;
}

.sidebar-close {
    width: 32px;
    height: 32px;
    border: none;
    background: var(--card);
    color: var(--muted);
    cursor: pointer;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    transition: all var(--transition-fast);
}
.sidebar-close:hover {
    color: var(--fg);
    background: var(--separator);
}

.sidebar-content {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 12px;
    -webkit-overflow-scrolling: touch;
}

.sidebar-empty {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 60px 20px;
    color: var(--muted);
    text-align: center;
}
.sidebar-empty i {
    font-size: 44px;
    margin-bottom: 16px;
    opacity: 0.35;
}
.sidebar-empty p {
    font-size: 15px;
    font-weight: 500;
    margin-bottom: 6px;
    color: var(--fg);
}
.sidebar-empty span {
    font-size: 13px;
    opacity: 0.7;
}

.sidebar-list {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.sidebar-footer {
    padding: 14px 16px;
    padding-bottom: max(14px, env(safe-area-inset-bottom));
    border-top: 1px solid var(--border);
    flex-shrink: 0;
}

.ip-badge {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 12px;
    color: var(--muted);
    background: var(--card);
    padding: 8px 14px;
    border-radius: 100px;
    border: 1px solid var(--border);
    font-variant-numeric: tabular-nums;
}

/* ========== 设置面板（折叠式） ========== */
.settings-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.20);
    z-index: 209;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-base), visibility var(--transition-base);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}
.settings-overlay.active {
    opacity: 1;
    visibility: visible;
}

.settings-panel {
    position: fixed;
    top: 0;
    right: 0;
    width: 360px;
    max-width: 90vw;
    height: 100%;
    height: 100dvh;
    background: var(--bg);
    border-left: 1px solid var(--border);
    z-index: 210;
    transform: translateX(100%);
    transition: transform var(--transition-slow);
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-xl);
}
.settings-panel.active {
    transform: translateX(0);
}

.settings-header {
    padding: 20px 16px;
    padding-top: max(20px, env(safe-area-inset-top));
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-shrink: 0;
}

.settings-title {
    font-size: 15px;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 8px;
    letter-spacing: -0.2px;
}

.settings-close {
    width: 32px;
    height: 32px;
    border: none;
    background: var(--card);
    color: var(--muted);
    cursor: pointer;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    transition: all var(--transition-fast);
}
.settings-close:hover {
    color: var(--fg);
    background: var(--separator);
}

.settings-content {
    flex: 1;
    overflow-y: auto;
    padding: 16px;
    -webkit-overflow-scrolling: touch;
}

.settings-section {
    margin-bottom: 24px;
}

.settings-section-title {
    font-size: 11px;
    font-weight: 600;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 8px;
    padding-left: 4px;
}

.settings-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    margin-bottom: 8px;
    transition: all var(--transition-fast);
    cursor: pointer;
}
.settings-item:hover {
    background: var(--card-hover);
    border-color: var(--muted-light);
}

.settings-item-info {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.settings-item-label {
    font-size: 14px;
    font-weight: 500;
    color: var(--fg);
}

.settings-item-desc {
    font-size: 12px;
    color: var(--muted);
}

.settings-link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    margin-bottom: 8px;
    transition: all var(--transition-fast);
    text-decoration: none;
    color: inherit;
}
.settings-link:hover {
    background: var(--card-hover);
    border-color: var(--muted-light);
}
.settings-link i {
    color: var(--muted);
    font-size: 16px;
}

/* Toggle 开关 */
.toggle-btn {
    border: none;
    background: none;
    cursor: pointer;
    padding: 0;
    display: flex;
    align-items: center;
}
.toggle-track {
    width: 44px;
    height: 24px;
    background: var(--border);
    border-radius: 12px;
    position: relative;
    transition: background var(--transition-fast);
}
.toggle-thumb {
    width: 20px;
    height: 20px;
    background: var(--bg);
    border-radius: 50%;
    position: absolute;
    top: 2px;
    left: 2px;
    transition: transform var(--transition-fast);
    box-shadow: var(--shadow-sm);
}
.toggle-btn.active .toggle-track {
    background: var(--fg);
}
.toggle-btn.active .toggle-thumb {
    transform: translateX(20px);
}

/* ========== 历史对话项 ========== */
.history-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 10px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
    opacity: 0;
    transform: translateX(-8px);
    animation: slideInLeft 0.4s forwards;
    position: relative;
    overflow: hidden;
    border: 1px solid transparent;
}
@keyframes slideInLeft {
    to { opacity: 1; transform: translateX(0); }
}
.history-item:hover {
    background: var(--card);
    border-color: var(--border);
    transform: translateX(2px);
}
.history-item.active {
    background: var(--fg);
    color: var(--bg);
    border-color: var(--fg);
}
.history-item.active .history-time,
.history-item.active .history-btn {
    color: var(--bg);
    opacity: 0.6;
}

.history-icon {
    width: 36px;
    height: 36px;
    border-radius: 10px;
    background: var(--card);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--muted);
    font-size: 18px;
    flex-shrink: 0;
    border: 1px solid var(--border);
    transition: all var(--transition-fast);
}
.history-item:hover .history-icon {
    background: var(--bg);
    color: var(--fg);
}
.history-item.active .history-icon {
    background: rgba(255,255,255,0.15);
    color: var(--bg);
    border-color: transparent;
}

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

.history-title {
    font-size: 14px;
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-bottom: 3px;
    line-height: 1.3;
}

.history-time {
    font-size: 11px;
    color: var(--muted);
    opacity: 0.8;
    font-variant-numeric: tabular-nums;
}

.history-actions {
    display: flex;
    gap: 4px;
    opacity: 0;
    transition: opacity var(--transition-fast);
}
.history-item:hover .history-actions {
    opacity: 1;
}

.history-btn {
    width: 28px;
    height: 28px;
    border: none;
    background: transparent;
    color: var(--muted);
    cursor: pointer;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    transition: all var(--transition-fast);
}
.history-btn:hover {
    background: var(--separator);
    color: var(--fg);
}
.history-item.active .history-btn:hover {
    background: rgba(255,255,255,0.2);
    color: var(--bg);
}

/* ========== 头部 ========== */
.header {
    background: rgba(255,255,255,0.85);
    border-bottom: 1px solid var(--border);
    padding: 14px 16px;
    padding-top: max(14px, env(safe-area-inset-top));
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-shrink: 0;
    position: sticky;
    top: 0;
    z-index: 50;
    backdrop-filter: blur(24px) saturate(180%);
    -webkit-backdrop-filter: blur(24px) saturate(180%);
    transition: all var(--transition-slow);
}
[data-theme="dark"] .header {
    background: rgba(10,10,10,0.85);
}

.header-title {
    font-size: 16px;
    font-weight: 700;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    letter-spacing: -0.5px;
    color: var(--fg);
}

.header-actions {
    display: flex;
    gap: 6px;
    margin-left: auto;
}

.header-btn {
    width: 36px;
    height: 36px;
    background: var(--card);
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    border-radius: 50%;
    color: var(--muted);
    font-size: 18px;
    position: relative;
    z-index: 51;
    transition: all var(--transition-fast);
}
.header-btn:hover { 
    color: var(--fg); 
    border-color: var(--muted);
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
    background: var(--card-hover);
}

/* ========== 消息区域 & 滚动条 ========== */
.messages-area {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    position: relative;
    -webkit-overflow-scrolling: touch;
    padding: 28px 0;
    scroll-behavior: smooth;
}

.messages-area::-webkit-scrollbar {
    width: 5px;
}
.messages-area::-webkit-scrollbar-track {
    background: transparent;
    margin: 8px 0;
}
.messages-area::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 10px;
    border: 1px solid transparent;
    background-clip: padding-box;
}
.messages-area::-webkit-scrollbar-thumb:hover {
    background: var(--muted);
}

/* ========== 欢迎界面 ========== */
.welcome-screen {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 24px;
    opacity: 0;
    animation: fadeIn 0.8s 0.15s cubic-bezier(0.16, 1, 0.3, 1) forwards;
    z-index: 1;
    pointer-events: none;
}
.welcome-screen > * { pointer-events: auto; }

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}

.welcome-time {
    font-size: 14px;
    color: var(--muted);
    margin-bottom: 10px;
    font-weight: 500;
    opacity: 0;
    animation: fadeIn 0.6s 0.25s cubic-bezier(0.16, 1, 0.3, 1) forwards;
    letter-spacing: 0.5px;
}

.welcome-title {
    font-size: 36px;
    font-weight: 800;
    color: var(--fg);
    margin-bottom: 28px;
    letter-spacing: -1px;
    opacity: 0;
    animation: fadeIn 0.6s 0.4s cubic-bezier(0.16, 1, 0.3, 1) forwards;
    line-height: 1.2;
}

.welcome-suggestion {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 14px 24px;
    font-size: 14px;
    color: var(--muted);
    display: inline-block;
    transition: all var(--transition-base);
    opacity: 0;
    animation: fadeIn 0.6s 0.55s cubic-bezier(0.16, 1, 0.3, 1) forwards;
    cursor: default;
    box-shadow: var(--shadow-sm);
}
.welcome-suggestion:hover {
    border-color: var(--muted);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* ========== 消息动画 ========== */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px) scale(0.97); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}

.message-wrapper {
    margin-bottom: 24px;
    animation: fadeInUp 0.5s cubic-bezier(0.16, 1, 0.3, 1) both;
    position: relative;
    padding: 0 18px;
    width: 100%;
}

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

.user-bubble {
    background: var(--user-bubble);
    color: var(--user-bubble-text);
    padding: 12px 18px;
    border-radius: 20px;
    border-bottom-right-radius: 6px;
    font-size: 15px;
    line-height: 1.55;
    max-width: 82%;
    word-wrap: break-word;
    display: inline-block;
    box-shadow: 0 4px 12px rgba(0,0,0,0.12);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
    position: relative;
    letter-spacing: 0.2px;
}
.user-bubble::after {
    content: '';
    position: absolute;
    bottom: 0;
    right: -6px;
    width: 12px;
    height: 12px;
    background: inherit;
    border-radius: 0 0 0 12px;
    clip-path: polygon(0 0, 100% 100%, 0 100%);
}
.user-bubble:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 16px rgba(0,0,0,0.16);
}

.message-wrapper.ai {
    position: relative;
}
.message-wrapper.ai::before {
    content: '';
    position: absolute;
    left: 18px;
    top: 8px;
    bottom: 8px;
    width: 3px;
    background: linear-gradient(180deg, var(--fg) 0%, var(--muted) 100%);
    border-radius: 3px;
    opacity: 0.15;
}

.ai-header {
    font-size: 13px;
    font-weight: 700;
    color: var(--muted);
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-left: 14px;
    letter-spacing: 0.3px;
}

.ai-content {
    font-size: 15px;
    line-height: 1.65;
    color: var(--fg);
    max-width: 100%;
    word-wrap: break-word;
    overflow-wrap: break-word;
    padding-left: 14px;
}

/* 复制按钮 */
.copy-btn {
    background: var(--card);
    border: 1px solid var(--border);
    padding: 5px 10px;
    cursor: pointer;
    color: var(--muted);
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    gap: 5px;
    font-size: 12px;
    font-family: inherit;
    border-radius: 8px;
    font-weight: 500;
}
.copy-btn:hover { 
    opacity: 1; 
    background: var(--fg);
    color: var(--bg);
    border-color: var(--fg);
    transform: translateY(-1px);
}
.copy-btn.copied {
    color: var(--fg);
    opacity: 1;
    background: var(--card);
    border-color: var(--fg);
}

/* 统计信息 */
.message-stats {
    margin-top: 10px;
    font-size: 11px;
    color: var(--muted);
    background: var(--separator);
    padding: 8px 12px;
    border-radius: 10px;
    display: inline-flex;
    flex-wrap: wrap;
    gap: 8px 16px;
    opacity: 0;
    transform: translateY(-4px);
    transition: opacity var(--transition-base), transform var(--transition-base);
    margin-left: 14px;
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
}
.message-stats.visible {
    opacity: 1;
    transform: translateY(0);
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 4px;
}
.stat-value {
    font-weight: 700;
    color: var(--fg);
    font-variant-numeric: tabular-nums;
}

/* 加载动画 */
.loading-dots {
    display: flex;
    align-items: center;
    gap: 5px;
    padding: 6px 0;
    height: 28px;
    padding-left: 14px;
}
.loading-dots span {
    width: 7px;
    height: 7px;
    background: var(--muted);
    border-radius: 50%;
    animation: bounce 1.6s infinite ease-in-out both;
    opacity: 0.6;
}
.loading-dots span:nth-child(1) { animation-delay: -0.32s; }
.loading-dots span:nth-child(2) { animation-delay: -0.16s; }
@keyframes bounce {
    0%, 80%, 100% { transform: scale(0.5); opacity: 0.3; }
    40% { transform: scale(1); opacity: 1; }
}

/* Markdown */
.ai-content p { margin: 0 0 12px 0; }
.ai-content p:last-child { margin-bottom: 0; }
.ai-content code {
    background: var(--separator);
    padding: 3px 6px;
    border-radius: 5px;
    font-family: 'SF Mono', Monaco, 'Cascadia Code', monospace;
    font-size: 13px;
    white-space: pre-wrap;
    color: var(--fg);
    border: 1px solid var(--border);
}
.ai-content pre {
    background: #1a1a1a;
    color: #ECECF1;
    padding: 16px;
    border-radius: var(--radius-sm);
    overflow-x: auto;
    margin: 12px 0;
    font-size: 13px;
    width: 100%;
    max-width: 100%;
    border: 1px solid #2a2a2a;
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.05);
}
[data-theme="dark"] .ai-content pre {
    background: #111111;
    border-color: #222;
}
.ai-content pre code {
    background: none;
    padding: 0;
    color: inherit;
    white-space: pre;
    border: none;
    font-size: 13px;
    line-height: 1.6;
}
.ai-content ul, .ai-content ol {
    margin: 12px 0;
    padding-left: 24px;
}
.ai-content li { margin: 6px 0; }
.ai-content strong { font-weight: 700; color: var(--fg); }
.ai-content em { font-style: italic; opacity: 0.9; }
.ai-content blockquote {
    border-left: 3px solid var(--fg);
    padding-left: 14px;
    margin: 12px 0;
    color: var(--muted);
    font-style: italic;
    opacity: 0.85;
}
.ai-content a {
    color: var(--fg);
    text-decoration: underline;
    text-underline-offset: 3px;
    text-decoration-thickness: 1.5px;
    opacity: 0.8;
    transition: opacity var(--transition-fast);
}
.ai-content a:hover { opacity: 1; }
.ai-content hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 16px 0;
}

/* 弹窗 */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.30);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-base), visibility var(--transition-base);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}
.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}
.modal-content {
    background: var(--card);
    width: 300px;
    border-radius: var(--radius-md);
    overflow: hidden;
    transform: scale(0.92) translateY(12px);
    transition: transform var(--transition-slow);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border);
}
.modal-overlay.active .modal-content {
    transform: scale(1) translateY(0);
}
.modal-body {
    padding: 28px 20px;
    text-align: center;
}
.modal-title {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 10px;
    letter-spacing: -0.3px;
}
.modal-text {
    font-size: 14px;
    color: var(--muted);
    line-height: 1.5;
}
.modal-actions {
    display: flex;
    border-top: 1px solid var(--border);
}
.modal-btn {
    flex: 1;
    padding: 14px;
    font-size: 16px;
    font-family: inherit;
    background: transparent;
    border: none;
    cursor: pointer;
    color: var(--fg);
    transition: all var(--transition-fast);
    font-weight: 500;
}
.modal-btn:hover { background: var(--separator); }
.modal-btn.cancel {
    border-right: 1px solid var(--border);
    color: var(--muted);
}
.modal-btn.confirm {
    font-weight: 700;
}

/* 输入区域 */
.input-container {
    background: rgba(248,249,250,0.90);
    border-top: 1px solid var(--border);
    padding: 12px 14px;
    padding-bottom: max(12px, calc(env(safe-area-inset-bottom) + 12px));
    flex-shrink: 0;
    transition: all var(--transition-slow);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
}
[data-theme="dark"] .input-container {
    background: rgba(20,20,20,0.90);
}
.input-row {
    display: flex;
    align-items: flex-end;
    gap: 10px;
    max-width: 100%;
}
.input-field {
    flex: 1;
    background: var(--input-bg);
    border: 1.5px solid var(--border);
    border-radius: 22px;
    padding: 11px 18px;
    font-size: 15px;
    font-family: inherit;
    resize: none;
    max-height: 120px;
    min-height: 44px;
    outline: none;
    line-height: 1.45;
    color: var(--fg);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}
.input-field:focus {
    border-color: var(--fg);
    box-shadow: 0 0 0 4px var(--separator), var(--shadow-md);
    transform: translateY(-1px);
}
.input-field::placeholder {
    color: var(--muted);
    opacity: 0.6;
}
.send-button, .stop-button {
    width: 44px;
    height: 44px;
    border: none;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    flex-shrink: 0;
    color: var(--user-bubble-text);
    font-size: 20px;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}
.send-button::before, .stop-button::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, transparent 0%, rgba(255,255,255,0.1) 100%);
    opacity: 0;
    transition: opacity var(--transition-fast);
}
.send-button:hover::before, .stop-button:hover::before {
    opacity: 1;
}
.send-button:hover, .stop-button:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}
.send-button {
    background: var(--fg);
}
.stop-button {
    background: #555555;
}
.hidden {
    display: none !important;
}

/* ========== 响应式 ========== */
@media (max-width: 480px) {
    .sidebar { width: 280px; }
    .settings-panel { width: 100%; }
    .history-actions { opacity: 1; }
    .header-title { font-size: 15px; }
    .welcome-title { font-size: 28px; }
    .user-bubble { max-width: 88%; }
    .message-wrapper { padding: 0 14px; }
    .message-wrapper.ai::before { left: 14px; }
    .ai-header, .ai-content { padding-left: 10px; }
    .message-stats { margin-left: 10px; }
    .loading-dots { padding-left: 10px; }
}

@media (max-width: 360px) {
    .header { padding: 10px 12px; }
    .header-btn { width: 32px; height: 32px; font-size: 16px; }
    .input-field { padding: 9px 14px; font-size: 14px; }
    .send-button, .stop-button { width: 40px; height: 40px; }
}