/* ==================== CSS 变量 ==================== */
:root {
  /* 主色 */
  --primary: #1976D2;
  --primary-dark: #0D47A1;
  --primary-light: #BBDEFB;
  --accent: #03A9F4;
  --accent-secondary: #FF6F00;

  /* 背景 */
  --bg-main: #F0F2F5;
  --bg-card: #FFFFFF;
  --bg-surface: #FAFAFA;
  --bg-hover: #F5F7FA;

  /* 文字 */
  --text-primary: #1A237E;
  --text-body: #202124;
  --text-secondary: #5F6368;
  --text-hint: #9AA0A6;
  --text-white: #FFFFFF;

  /* 状态 */
  --status-connected: #2E7D32;
  --status-connecting: #F57C00;
  --status-error: #C62828;
  --status-disconnected: #757575;

  /* 语义色 */
  --success: #4CAF50;
  --warning: #FF9800;
  --error: #F44336;
  --info: #2196F3;

  /* 分隔线 */
  --divider: #EBEEF0;
  --border: #E0E0E0;

  /* 树视图 */
  --tree-folder: #1565C0;
  --tree-file: #5F6368;
  --tree-bg: #F5F7FA;
  --tree-selected: #E3F2FD;
  --tree-target: #FFF3E0;

  /* 圆角 */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;

  /* 阴影 */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 2px 8px rgba(0,0,0,0.10);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.12);

  /* 过渡 */
  --transition: 0.2s ease;
}

/* ==================== 全局重置 ==================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Noto Sans CJK SC', sans-serif;
  background: var(--bg-main);
  color: var(--text-body);
  line-height: 1.6;
  min-height: 100vh;
}

/* ==================== 头部 ==================== */
.header {
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
  color: var(--text-white);
  padding: 0;
  box-shadow: var(--shadow-md);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-content {
  max-width: 960px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

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

.header-icon {
  font-size: 32px;
}

.header-title {
  font-size: 22px;
  font-weight: 700;
  margin: 0;
}

.header-subtitle {
  font-size: 13px;
  opacity: 0.85;
  margin: 0;
}

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

.status-indicator {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  background: rgba(255,255,255,0.15);
  border-radius: var(--radius-sm);
}

.status-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.status-dot-disconnected {
  background: var(--status-disconnected);
  box-shadow: 0 0 0 3px rgba(117,117,117,0.2);
}

.status-dot-connecting {
  background: var(--status-connecting);
  animation: pulse 1.2s infinite;
}

.status-dot-connected {
  background: var(--status-connected);
  box-shadow: 0 0 0 3px rgba(46,125,50,0.2);
}

.status-dot-error {
  background: var(--status-error);
  box-shadow: 0 0 0 3px rgba(198,40,40,0.2);
}

@keyframes pulse {
  0%, 100% { opacity: 1; box-shadow: 0 0 0 3px rgba(245,124,0,0.3); }
  50% { opacity: 0.5; box-shadow: 0 0 0 6px rgba(245,124,0,0.1); }
}

.status-text {
  font-size: 14px;
  font-weight: 500;
}

/* ==================== 主内容 ==================== */
.main {
  max-width: 960px;
  margin: 0 auto;
  padding: 24px 16px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* ==================== 卡片 ==================== */
.card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: var(--transition);
  border: 1px solid var(--divider);
}

.card:hover {
  box-shadow: var(--shadow-md);
}

.card-disabled {
  opacity: 0.55;
  pointer-events: none;
}

.card-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--divider);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.card-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
}

.card-actions {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

/* ==================== 按钮 ==================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px 16px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
  font-family: inherit;
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.btn-sm {
  padding: 6px 12px;
  font-size: 13px;
}

.btn-lg {
  padding: 12px 24px;
  font-size: 16px;
  width: 100%;
}

.btn-primary {
  background: var(--primary);
  color: var(--text-white);
}

.btn-primary:hover:not(:disabled) {
  background: var(--primary-dark);
}

.btn-primary-outline {
  background: transparent;
  color: var(--primary);
  border: 1.5px solid var(--primary);
}

.btn-primary-outline:hover:not(:disabled) {
  background: var(--primary-light);
}

.btn-outline {
  background: var(--bg-surface);
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.btn-outline:hover:not(:disabled) {
  background: var(--bg-hover);
  border-color: var(--primary);
  color: var(--primary);
}

.btn-danger {
  background: var(--error);
  color: var(--text-white);
}

.btn-danger:hover:not(:disabled) {
  background: #D32F2F;
}

.btn-danger-outline {
  background: transparent;
  color: var(--error);
  border: 1px solid var(--error);
}

.btn-danger-outline:hover:not(:disabled) {
  background: #FFEBEE;
}

/* ==================== 设备列表 ==================== */
.device-list {
  padding: 12px 20px;
}

.empty-hint {
  padding: 24px;
  text-align: center;
  color: var(--text-hint);
  font-size: 14px;
}

.device-card {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 16px;
  border-radius: var(--radius-md);
  background: var(--bg-surface);
  border: 1px solid var(--divider);
  margin-bottom: 8px;
  transition: var(--transition);
}

.device-card:last-child {
  margin-bottom: 0;
}

.device-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-sm);
}

.device-card-active {
  border-color: var(--success);
  background: #E8F5E9;
}

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

.device-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-body);
  margin-bottom: 4px;
}

.device-meta {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--text-secondary);
}

.device-sep {
  color: var(--text-hint);
}

.device-actions {
  display: flex;
  gap: 8px;
  flex-shrink: 0;
}

.btn-icon {
  padding: 6px 14px;
  font-size: 13px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-secondary);
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
}

.btn-icon:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.btn-connect {
  background: var(--primary);
  color: var(--text-white);
  border-color: var(--primary);
}

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

.btn-danger {
  color: var(--error);
}

.btn-danger:hover {
  border-color: var(--error);
  color: var(--error);
  background: #FFEBEE;
}

/* ==================== 文件树 ==================== */
.tree-status {
  padding: 8px 20px;
  border-bottom: 1px solid var(--divider);
}

.tree-status-text {
  font-size: 13px;
  color: var(--text-secondary);
}

.tree-container {
  padding: 8px 12px;
  max-height: 400px;
  overflow-y: auto;
  background: var(--tree-bg);
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

.tree-node {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  user-select: none;
}

.tree-node:hover {
  background: var(--bg-hover);
}

.tree-node-selected {
  background: var(--tree-selected);
}

.tree-node-target {
  background: var(--tree-target);
}

.tree-icon-folder {
  font-size: 18px;
}

.tree-icon-file {
  font-size: 16px;
  opacity: 0.7;
}

.tree-name {
  font-size: 14px;
  color: var(--text-body);
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.tree-target-badge {
  font-size: 11px;
  padding: 2px 8px;
  background: var(--accent-secondary);
  color: var(--text-white);
  border-radius: 10px;
  font-weight: 500;
}

.tree-children {
  /* 子节点容器 */
}

/* ==================== 文件传输 ==================== */
.transfer-section {
  padding: 12px 20px;
  border-bottom: 1px solid var(--divider);
}

.transfer-section:last-child {
  border-bottom: none;
}

.transfer-label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.file-select-area {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

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

.file-name {
  display: block;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-body);
}

.file-detail {
  font-size: 12px;
  color: var(--text-secondary);
}

.target-folder-display {
  padding: 10px 14px;
  background: var(--bg-surface);
  border: 1px solid var(--divider);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--primary);
  font-weight: 500;
}

/* 进度条 */
.progress-container {
  padding: 12px 20px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.progress-bar {
  flex: 1;
  height: 8px;
  border: none;
  border-radius: 4px;
  background: var(--divider);
  overflow: hidden;
}

.progress-bar::-webkit-progress-bar {
  background: var(--divider);
  border-radius: 4px;
}

.progress-bar::-webkit-progress-value {
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 4px;
  transition: width 0.3s;
}

.progress-bar::-moz-progress-bar {
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 4px;
}

.progress-text {
  font-size: 13px;
  color: var(--text-secondary);
  white-space: nowrap;
}

/* ==================== 传输记录 ==================== */
.history-list {
  padding: 8px 20px;
  max-height: 300px;
  overflow-y: auto;
}

.history-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 0;
  border-bottom: 1px solid var(--divider);
}

.history-item:last-child {
  border-bottom: none;
}

.history-icon {
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  font-size: 14px;
  font-weight: 700;
  flex-shrink: 0;
}

.history-icon-success {
  background: #E8F5E9;
  color: var(--success);
}

.history-icon-fail {
  background: #FFEBEE;
  color: var(--error);
}

.history-name {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-body);
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.history-detail {
  font-size: 12px;
  color: var(--text-secondary);
}

.history-time {
  font-size: 11px;
  color: var(--text-hint);
  white-space: nowrap;
}

/* ==================== 日志面板 ==================== */
.log-panel {
  overflow: hidden;
  transition: var(--transition);
}

.log-panel.collapsed {
  max-height: 0;
}

.log-container {
  padding: 8px 20px;
  max-height: 240px;
  overflow-y: auto;
  font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
  font-size: 12px;
}

.log-line {
  padding: 3px 0;
  border-bottom: 1px solid rgba(0,0,0,0.03);
  word-break: break-all;
}

.log-info { color: var(--text-secondary); }
.log-success { color: var(--success); }
.log-warning { color: var(--warning); }
.log-error { color: var(--error); }
.log-send { color: var(--primary); }
.log-receive { color: var(--accent); }

/* ==================== 弹窗 ==================== */
.overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0,0,0,0.5);
  display: none;
  justify-content: center;
  align-items: center;
  z-index: 1000;
  padding: 16px;
}

.overlay-visible {
  display: flex;
}

.modal {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 480px;
  max-height: 90vh;
  overflow-y: auto;
}

.modal-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--divider);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-primary);
}

.modal-close {
  width: 32px;
  height: 32px;
  border: none;
  background: var(--bg-surface);
  border-radius: 50%;
  font-size: 20px;
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.modal-close:hover {
  background: var(--error);
  color: var(--text-white);
}

.modal-body {
  padding: 20px;
}

.scan-status {
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  background: var(--bg-surface);
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 16px;
  text-align: center;
}

.scan-status-active {
  background: #FFF3E0;
  color: var(--warning);
}

.scan-status-success {
  background: #E8F5E9;
  color: var(--success);
}

.scan-status-error {
  background: #FFEBEE;
  color: var(--error);
}

.form-group {
  margin-bottom: 16px;
}

.form-row {
  display: flex;
  gap: 12px;
}

.form-row .form-group {
  flex: 1;
}

.form-label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-body);
  margin-bottom: 6px;
}

.form-input, .form-select {
  width: 100%;
  padding: 10px 12px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--text-body);
  background: var(--bg-card);
  transition: var(--transition);
  font-family: inherit;
}

.form-input:focus, .form-select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(25,118,210,0.1);
}

.form-hint {
  font-size: 12px;
  color: var(--text-hint);
  margin-top: 4px;
}

.modal-actions {
  display: flex;
  gap: 12px;
  justify-content: flex-end;
  margin-top: 20px;
}

/* ==================== Toast ==================== */
.toast-container {
  position: fixed;
  top: 80px;
  right: 16px;
  z-index: 2000;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.toast {
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  animation: slideIn 0.3s ease;
  max-width: 320px;
}

.toast-info {
  background: var(--info);
  color: var(--text-white);
}

.toast-success {
  background: var(--success);
  color: var(--text-white);
}

.toast-warning {
  background: var(--warning);
  color: var(--text-white);
}

.toast-error {
  background: var(--error);
  color: var(--text-white);
}

.toast-fade {
  opacity: 0;
  transform: translateX(20px);
  transition: all 0.3s;
}

@keyframes slideIn {
  from { opacity: 0; transform: translateX(40px); }
  to { opacity: 1; transform: translateX(0); }
}

/* ==================== 页脚 ==================== */
.footer {
  text-align: center;
  padding: 24px 16px;
  font-size: 12px;
  color: var(--text-hint);
}

/* ==================== 滚动条 ==================== */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-hint);
}

/* ==================== 响应式 ==================== */
@media (max-width: 640px) {
  .header-content {
    padding: 12px 16px;
  }

  .header-title {
    font-size: 18px;
  }

  .header-subtitle {
    font-size: 12px;
  }

  .main {
    padding: 16px 12px;
  }

  .card-header {
    padding: 12px 16px;
  }

  .card-actions {
    gap: 6px;
  }

  .btn-sm {
    padding: 5px 10px;
    font-size: 12px;
  }

  .form-row {
    flex-direction: column;
  }

  .toast-container {
    right: 8px;
    left: 8px;
  }

  .toast {
    max-width: none;
  }
}