/**
 * Responsive Design for AI Chat Application
 * Mobile-first approach with breakpoints for different screen sizes
 */

/* Mobile First Base Styles (up to 640px) */
@media (max-width: 640px) {
  /* App Layout */
  .app-container {
    flex-direction: column;
  }

  /* Sidebar Mobile Behavior */
  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    transform: translateX(-100%);
    z-index: var(--z-modal);
    transition: transform var(--transition-normal);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .sidebar-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: calc(var(--z-modal) - 1);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
  }

  .sidebar-overlay.active {
    opacity: 1;
    visibility: visible;
  }

  /* Settings Modal Mobile */
  .settings-content {
    width: 95%;
    max-height: 90vh;
    margin: var(--spacing-4);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-2xl);
  }

  .settings-header {
    padding: var(--spacing-4) var(--spacing-5);
  }

  .settings-body {
    padding: var(--spacing-4) var(--spacing-5);
  }

  /* 主内容区域调整 - 为固定input-container预留空间 + 键盘适配 */
  .main-content {
    height: calc(100dvh - 120px);
    height: calc(100vh - 120px); /* fallback */
    padding-bottom: 120px !important; /* 为input-container预留足够空间 */
    overflow-y: auto;
    flex: 1;
    display: flex;
    flex-direction: column;
    
    /* 键盘适配：支持动态padding调整 */
    transition: var(--keyboard-transition, padding-bottom 300ms ease-out);
    
    /* 确保在键盘弹出时内容可滚动 */
    scroll-behavior: smooth;
  }

  /* Header Mobile */
  .chat-header {
    padding: 0 var(--spacing-4);
    height: 56px;
  }

  .sidebar-toggle {
    display: flex;
  }

  .chat-title {
    font-size: var(--font-size-base);
  }

  /* Messages Mobile */
  .messages-container {
    padding: var(--spacing-3) var(--spacing-4);
  }

  .message {
    padding: var(--spacing-4) var(--spacing-4);
    margin-bottom: var(--spacing-4);
    border-radius: var(--radius-xl);
  }

  .message-content {
    padding: var(--spacing-3) var(--spacing-4);
    border-radius: var(--radius-lg);
  }

  .message {
    max-width: 100%;
  }

  .message-avatar {
    width: 28px;
    height: 28px;
    font-size: var(--font-size-xs);
  }

  .message-body {
    padding: var(--spacing-3);
  }

  /* Welcome Message Mobile */
  .welcome-message {
    padding: var(--spacing-8) var(--spacing-4);
  }

  .welcome-hero {
    margin-bottom: var(--spacing-8);
  }

  .welcome-icon-container {
    margin-bottom: var(--spacing-6);
  }

  .welcome-icon {
    width: 60px;
    height: 60px;
  }

  .welcome-icon-glow {
    width: 90px;
    height: 90px;
  }

  .welcome-title {
    font-size: var(--font-size-2xl);
  }

  .welcome-subtitle {
    font-size: var(--font-size-base);
  }

  .welcome-features {
    gap: var(--spacing-4);
    margin-bottom: var(--spacing-8);
  }

  .feature-item {
    min-width: 100px;
    padding: var(--spacing-3);
  }

  .feature-icon {
    width: 32px;
    height: 32px;
  }

  .prompts-title {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-4);
  }

  .suggested-prompts {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-3);
    max-width: 100%;
    padding: var(--spacing-2) var(--spacing-2);
  }

  .suggested-prompt {
    padding: var(--spacing-3) var(--spacing-2);
    min-height: 70px;
  }
  
  .suggested-prompt-content {
    padding: var(--spacing-3);
    gap: var(--spacing-2);
  }
  
  .suggested-prompt-icon {
    width: 2rem;
    height: 2rem;
    font-size: 1.25rem;
  }
  
  .suggested-prompt-text {
    font-size: var(--font-size-sm);
  }
  
  .suggested-prompt-description {
    font-size: var(--font-size-xs);
  }

  /* Input Container Mobile - 彻底修复跨平台显示问题 + 键盘适配 */
  .input-container {
    padding: var(--spacing-3) var(--spacing-4);
    background: linear-gradient(135deg, var(--color-background) 0%, var(--color-surface) 100%);
    border-top: 1px solid var(--color-border);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    
    /* 强制固定定位，避免被浏览器UI遮挡 */
    position: fixed !important;
    bottom: 0 !important;
    left: 0 !important;
    right: 0 !important;
    width: 100% !important;
    z-index: 9999 !important;
    
    /* 关键：为不同平台预留足够空间 */
    padding-bottom: 20px !important;
    margin-bottom: 0 !important;
    
    /* 防止内容溢出和确保可见性 */
    flex-shrink: 0;
    min-height: 80px;
    max-height: 35vh;
    overflow-y: auto;
    
    /* 键盘适配：支持动态transform */
    transform: translateZ(0) translateY(0);
    -webkit-transform: translateZ(0) translateY(0);
    transition: var(--keyboard-transition, transform 300ms ease-out);
    
    /* 确保在键盘弹出时保持可见 */
    will-change: transform;
  }

  .input-wrapper {
    padding: var(--spacing-3);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-lg);
  }

  .message-input {
    font-size: 16px; /* Prevent zoom on iOS */
    max-height: 100px;
  }

  .file-upload-btn,
  .send-btn {
    padding: var(--spacing-2);
  }

  /* 确保消息列表在移动端正确显示 + 键盘适配 */
  .messages-list {
    padding: var(--spacing-4);
    padding-bottom: var(--spacing-6);
    overflow-y: auto;
    flex: 1;
    
    /* 键盘适配：确保平滑滚动 */
    scroll-behavior: smooth;
    -webkit-overflow-scrolling: touch;
  }

  /* 移动端键盘适配器基础类 */
  .mobile-keyboard-adapter {
    /* 启用硬件加速 */
    transform: translateZ(0);
    -webkit-transform: translateZ(0);
  }

  /* 键盘准备状态 - 优化启动响应速度 */
  .keyboard-preparing {
    /* 启用硬件加速，准备动画 */
    transform: translateZ(0);
    -webkit-transform: translateZ(0);
  }

  .keyboard-preparing .input-container,
  .keyboard-preparing .main-content {
    /* 预启用GPU加速 */
    will-change: transform;
    transform: translateZ(0);
    -webkit-transform: translateZ(0);
  }

  /* 键盘显示中状态 */
  .keyboard-showing {
    /* 显示过程中的优化 */
    pointer-events: none; /* 防止动画期间的意外交互 */
  }

  .keyboard-showing .input-container,
  .keyboard-showing .main-content {
    /* 显示动画期间的性能优化 */
    will-change: transform, padding-bottom;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
  }

  /* 键盘可见状态的全局样式 */
  .keyboard-visible {
    /* 防止页面滚动 */
    overflow: hidden;
  }

  /* 键盘隐藏准备状态 */
  .keyboard-hiding-preparing {
    /* 隐藏准备阶段的优化 */
    transform: translateZ(0);
    -webkit-transform: translateZ(0);
  }

  .keyboard-hiding-preparing .input-container,
  .keyboard-hiding-preparing .main-content {
    /* 预启用GPU加速 */
    will-change: transform, padding-bottom;
    transform: translateZ(0);
    -webkit-transform: translateZ(0);
  }

  /* 键盘隐藏中状态 */
  .keyboard-hiding {
    /* 隐藏过程中的优化 */
    pointer-events: none; /* 防止动画期间的意外交互 */
  }

  .keyboard-hiding .input-container,
  .keyboard-hiding .main-content {
    /* 隐藏动画期间的性能优化 */
    will-change: transform, padding-bottom;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
  }

  /* 键盘可见时的输入容器样式 */
  .keyboard-visible .input-container {
    /* 增强阴影效果，突出输入区域 */
    box-shadow: 0 -8px 32px rgba(0, 0, 0, 0.12), 
                0 -4px 16px rgba(0, 0, 0, 0.08);
    z-index: 10000 !important;
    
    /* 确保在键盘上方 */
    position: relative;
    
    /* 启用硬件加速 */
    transform: translateZ(0);
    -webkit-transform: translateZ(0);
    will-change: transform;
  }

  /* 键盘可见时的主内容区域 */
  .keyboard-visible .main-content {
    /* 限制最大高度，确保内容可见 */
    max-height: calc(100vh - var(--keyboard-height, 0px) - 120px);
    overflow-y: auto;
    
    /* 启用硬件加速 */
    transform: translateZ(0);
    -webkit-transform: translateZ(0);
    will-change: transform, padding-bottom;
  }

  /* iOS 设备特定样式 - 增强版 */
  .ios-device.keyboard-preparing .input-container,
  .ios-device.keyboard-showing .input-container,
  .ios-device.keyboard-visible .input-container,
  .ios-device.keyboard-hiding .input-container {
    /* iOS 使用更平滑的弹性贝塞尔曲线 */
    transition: transform 300ms cubic-bezier(0.25, 0.46, 0.45, 0.94);
  }

  .ios-device.keyboard-preparing .main-content,
  .ios-device.keyboard-showing .main-content,
  .ios-device.keyboard-visible .main-content,
  .ios-device.keyboard-hiding .main-content {
    /* iOS 主内容区域平滑过渡 */
    transition: padding-bottom 300ms ease-out, 
                transform 300ms cubic-bezier(0.25, 0.46, 0.45, 0.94);
  }

  /* iOS 键盘显示时的特殊处理 */
  .ios-device.keyboard-showing .messages-container,
  .ios-device.keyboard-visible .messages-container {
    /* iOS 消息容器额外调整 */
    padding-bottom: 20px;
    transition: padding-bottom 300ms cubic-bezier(0.25, 0.46, 0.45, 0.94);
  }

  /* iOS 键盘隐藏时的恢复动画 */
  .ios-device.keyboard-hiding .messages-container {
    padding-bottom: 0;
    transition: padding-bottom 300ms cubic-bezier(0.25, 0.46, 0.45, 0.94);
  }

  /* Android 设备特定样式 - 增强版 */
  .android-device.keyboard-preparing .input-container,
  .android-device.keyboard-showing .input-container,
  .android-device.keyboard-visible .input-container,
  .android-device.keyboard-hiding .input-container {
    /* Android 使用标准缓动 */
    transition: transform 250ms ease-out;
  }

  .android-device.keyboard-preparing .main-content,
  .android-device.keyboard-showing .main-content,
  .android-device.keyboard-visible .main-content,
  .android-device.keyboard-hiding .main-content {
    /* Android 主内容区域过渡 */
    transition: padding-bottom 250ms ease-out, 
                transform 250ms ease-out;
  }

  /* Android 消息列表特殊处理 - 增强版 */
  .android-device.keyboard-showing .messages-list,
  .android-device.keyboard-visible .messages-list,
  .android-device.keyboard-showing .messages-container,
  .android-device.keyboard-visible .messages-container {
    /* Android 消息容器额外边距 */
    transition: margin-bottom 250ms ease-out;
  }

  /* Android 键盘隐藏时的恢复动画 */
  .android-device.keyboard-hiding .messages-list,
  .android-device.keyboard-hiding .messages-container {
    margin-bottom: 0;
    transition: margin-bottom 250ms ease-out;
  }

  /* 为支持动画的元素启用硬件加速 */
  .input-container,
  .main-content,
  .messages-container,
  .messages-list {
    /* 启用硬件加速 */
    transform: translateZ(0);
    -webkit-transform: translateZ(0);
    
    /* 优化重绘性能 */
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    
    /* 指定可能变化的属性 */
    will-change: transform;
  }

  /* 键盘动画期间的性能优化 */
  .keyboard-visible .input-container,
  .keyboard-visible .main-content {
    /* 动画期间指定变化属性 */
    will-change: transform, padding-bottom;
  }

  /* 输入框焦点状态优化 */
  .message-input:focus {
    /* 移除默认的焦点轮廓 */
    outline: none;
    
    /* 自定义焦点样式 */
    border-color: var(--color-primary, #007AFF);
    box-shadow: 0 0 0 2px rgba(0, 122, 255, 0.2);
    
    /* 平滑过渡 */
    transition: border-color 200ms ease-out, 
                box-shadow 200ms ease-out;
  }

  /* 键盘可见时输入框的增强样式 */
  .keyboard-visible .message-input:focus {
    /* 增强焦点效果 */
    box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.25),
                0 2px 8px rgba(0, 0, 0, 0.1);
  }

  /* 键盘过渡动画增强 */
  @media (prefers-reduced-motion: no-preference) {
    .input-container,
    .main-content {
      transition: var(--keyboard-transition, transform 300ms ease-out, padding-bottom 300ms ease-out);
    }
  }

  /* 为无障碍用户禁用动画 */
  @media (prefers-reduced-motion: reduce) {
    .input-container,
    .main-content,
    .messages-container,
    .messages-list {
      transition: none !important;
    }
    
    .keyboard-visible .input-container,
    .keyboard-visible .main-content {
      transition: none !important;
    }
  }

  /* 小屏幕设备优化 (< 480px) */
  @media (max-width: 479px) {
    .keyboard-visible .input-container {
      /* 小屏幕上减少阴影以提高性能 */
      box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.1);
    }
    
    .keyboard-visible .main-content {
      /* 小屏幕上调整最大高度 */
      max-height: calc(100vh - var(--keyboard-height, 0px) - 100px);
    }
  }

  /* 横屏模式优化 */
  @media (orientation: landscape) and (max-height: 500px) {
    .keyboard-visible .main-content {
      /* 横屏模式下减少上边距 */
      max-height: calc(100vh - var(--keyboard-height, 0px) - 80px);
    }
    
    .keyboard-visible .input-container {
      /* 横屏模式下减少阴影以节省空间 */
      box-shadow: 0 -2px 12px rgba(0, 0, 0, 0.08);
    }
  }

  /* 大屏幕设备禁用移动端键盘适配 (> 768px) */
  @media (min-width: 769px) {
    .mobile-keyboard-adapter {
      /* 大屏幕上禁用移动端键盘适配 */
      transform: none;
    }
    
    .keyboard-visible .input-container,
    .keyboard-visible .main-content {
      /* 重置大屏幕上的样式 */
      transform: none !important;
      transition: none !important;
      max-height: none !important;
      box-shadow: none !important;
    }
  }

  /* File Upload Mobile */
  .file-upload-area {
    padding: var(--spacing-3);
    margin-bottom: var(--spacing-3);
  }

  .uploaded-files {
    gap: var(--spacing-2);
  }

  .uploaded-file {
    padding: var(--spacing-2);
    font-size: var(--font-size-xs);
  }

  /* Modal Mobile */
  .modal-content {
    margin: var(--spacing-4);
    max-height: calc(100vh - var(--spacing-8));
    border-radius: var(--radius-lg);
  }

  /* Toast Mobile */
  .toast-container {
    padding: var(--spacing-4);
    bottom: calc(var(--spacing-4) + env(safe-area-inset-bottom));
  }

  .toast {
    margin-bottom: var(--spacing-2);
  }

  /* Code Block Mobile */
  .code-block {
    font-size: var(--font-size-sm);
    overflow-x: auto;
  }

  .code-header {
    padding: var(--spacing-2) var(--spacing-3);
  }

  .code-content {
    padding: var(--spacing-3);
  }

  /* Message Actions Mobile */
  .message-actions {
    position: static;
    opacity: 1;
    margin-top: var(--spacing-2);
    justify-content: flex-end;
  }

  .message-action-btn {
    padding: var(--spacing-2);
    min-width: 36px;
    min-height: 36px;
  }
}

/* Small Tablets (641px - 768px) */
@media (min-width: 641px) and (max-width: 768px) {
  .sidebar {
    width: 280px;
  }

  .messages-list {
    padding: var(--spacing-5) var(--spacing-4);
  }

  .message {
    max-width: 90%;
  }

  .suggested-prompts {
    grid-template-columns: repeat(3, 1fr);
  }

  .input-container {
    padding: var(--spacing-4) var(--spacing-5);
  }
}

/* Tablets (769px - 1024px) */
@media (min-width: 769px) and (max-width: 1024px) {
  .sidebar {
    width: var(--sidebar-width);
  }

  .messages-list {
    padding: var(--spacing-6) var(--spacing-5);
  }

  .message {
    max-width: 85%;
  }

  .suggested-prompts {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-4);
    max-width: 750px;
  }

  .input-container {
    padding: var(--spacing-4) var(--spacing-6);
  }

  .message-form {
    max-width: 700px;
  }
}

/* Desktop (1025px and up) */
@media (min-width: 1025px) {
  .sidebar {
    width: var(--sidebar-width);
  }

  .messages-list {
    padding: var(--spacing-6);
  }

  .message {
    max-width: var(--max-content-width);
  }

  .suggested-prompts {
    grid-template-columns: repeat(3, 1fr);
    max-width: 600px;
  }

  .input-container {
    padding: var(--spacing-4) var(--spacing-6) var(--spacing-6);
  }

  .message-form {
    max-width: var(--max-content-width);
  }
}

/* Large Desktop (1280px and up) */
@media (min-width: 1280px) {
  .sidebar {
    width: 260px;
  }

  .messages-list {
    padding: var(--spacing-8) var(--spacing-6);
  }

  .suggested-prompts {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-6);
    max-width: 900px;
  }

  .suggested-prompt {
    padding: var(--spacing-5) var(--spacing-4);
    min-height: 90px;
  }
}

/* Ultra-wide Desktop (1536px and up) */
@media (min-width: 1536px) {
  .app-container {
    max-width: 1400px;
    margin: 0 auto;
  }

  .sidebar {
    width: 260px;
  }

  .messages-list {
    padding: var(--spacing-10) var(--spacing-8);
  }
}

/* Landscape Mobile */
@media (max-width: 768px) and (orientation: landscape) {
  .chat-header {
    height: 48px;
  }

  .welcome-message {
    padding: var(--spacing-6) var(--spacing-4);
  }

  .welcome-icon {
    width: 40px;
    height: 40px;
  }

  .welcome-message h2 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-4);
  }

  .suggested-prompts {
    grid-template-columns: repeat(3, 1fr);
  }

  .input-container {
    padding: var(--spacing-2) var(--spacing-3);
  }
}

/* Touch Device Optimizations */
@media (hover: none) and (pointer: coarse) {
  /* Increase touch targets */
  .conversation-item {
    padding: var(--spacing-4);
  }

  .message-action-btn {
    min-width: 44px;
    min-height: 44px;
    padding: var(--spacing-3);
  }

  .file-upload-btn,
  .send-btn {
    min-width: 44px;
    min-height: 44px;
  }

  .new-chat-fab {
    width: 36px;
    height: 36px;
    bottom: var(--spacing-3);
    right: var(--spacing-3);
  }
  
  .new-chat-fab svg {
    width: 16px;
    height: 16px;
  }
  
  .settings-btn {
    min-height: 44px;
  }

  .suggested-prompt {
    min-height: 60px;
  }

  /* Remove hover effects on touch devices */
  .conversation-item:hover,
  .suggested-prompt:hover,
  .message-action-btn:hover {
    transform: none;
    box-shadow: none;
  }

  /* Always show message actions on touch devices */
  .message-actions {
    opacity: 1;
  }
}

/* High DPI Displays */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
  .loading-spinner {
    border-width: 2px;
  }

  .message-avatar {
    font-weight: var(--font-weight-bold);
  }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  .sidebar {
    transition: none;
  }

  .message {
    animation: none;
  }

  .loading-dots .dot {
    animation: none;
  }

  .suggested-prompt:hover {
    transform: none;
  }

  .loading-spinner {
    animation: none;
  }
}

/* Print Styles */
@media print {
  .sidebar,
  .chat-header,
  .input-container,
  .message-actions,
  .loading-indicator {
    display: none !important;
  }

  .main-content {
    width: 100% !important;
  }

  .messages-container {
    overflow: visible !important;
    height: auto !important;
  }

  .messages-list {
    padding: 0 !important;
  }

  .message {
    page-break-inside: avoid;
    margin-bottom: var(--spacing-4) !important;
  }

  .message-body {
    border: 1px solid #000 !important;
    background: white !important;
    color: black !important;
  }

  .code-block {
    background: #f5f5f5 !important;
    border: 1px solid #ccc !important;
  }
}

/* 跨平台安全区域和浏览器UI适配 */
@supports (padding: max(0px)) {
  .input-container {
    /* iOS安全区域适配 */
    padding-bottom: max(20px, env(safe-area-inset-bottom)) !important;
    bottom: env(safe-area-inset-bottom, 0px) !important;
  }

  .sidebar {
    padding-bottom: max(0px, env(safe-area-inset-bottom));
  }

  .toast-container {
    bottom: max(var(--spacing-4), env(safe-area-inset-bottom));
  }
}

/* Android浏览器导航栏适配 */
@media screen and (max-height: 700px) {
  .input-container {
    bottom: 10px !important;
    padding-bottom: 25px !important;
  }
}

/* 小屏设备特殊处理 */
@media screen and (max-height: 600px) {
  .input-container {
    bottom: 15px !important;
    padding-bottom: 30px !important;
    max-height: 30vh;
  }
}

/* Foldable Device Support */
@media (spanning: single-fold-vertical) {
  .app-container {
    flex-direction: row;
  }

  .sidebar {
    position: relative;
    transform: none;
    width: 50%;
  }

  .main-content {
    width: 50%;
  }
}

@media (spanning: single-fold-horizontal) {
  .app-container {
    flex-direction: column;
  }

  .sidebar {
    height: 40%;
    width: 100%;
  }

  .main-content {
    height: 60%;
  }
}

/* Container Queries (when supported) */
@supports (container-type: inline-size) {
  .messages-container {
    container-type: inline-size;
  }

  @container (max-width: 400px) {
    .message {
      max-width: 100%;
    }

    .message-avatar {
      width: 24px;
      height: 24px;
    }
  }

  @container (min-width: 600px) {
    .suggested-prompts {
      grid-template-columns: repeat(3, 1fr);
    }
  }
}

/* Accessibility Improvements for Small Screens */
@media (max-width: 480px) {
  /* Ensure minimum font sizes for readability */
  .message-text {
    font-size: max(var(--font-size-base), 16px);
  }

  .conversation-title {
    font-size: max(var(--font-size-sm), 14px);
  }

  /* Increase spacing for better touch interaction */
  .conversation-item {
    margin-bottom: var(--spacing-2);
  }

  /* Optimize code blocks for small screens */
  .code-block {
    font-size: max(var(--font-size-sm), 14px);
    border-radius: var(--radius-md);
  }

  .code-content {
    white-space: pre-wrap;
    word-break: break-word;
  }
}