:root {
  /* 现代配色方案 */
  --primary-color: #0066FF; /* 活力蓝 */
  --primary-hover: #0052CC;
  --bg-color: #F4F7FA;
  --text-main: #1F2937;
  --text-secondary: #6B7280;
  --border-color: #E5E7EB;
  --card-bg: #FFFFFF;
  --success-color: #10B981;
  --error-color: #EF4444;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --radius-md: 12px;
  --radius-lg: 16px;
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.app-container {
  max-width: 800px;
  margin: 0 auto;
  width: 100%;
  padding: 0 16px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

/* 头部样式 */
.app-header {
  text-align: center;
  padding: 32px 0 24px;
}

.logo-area {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 8px;
}

.icon-emoji {
  font-size: 36px;
  line-height: 1;
  filter: drop-shadow(0 2px 4px rgba(0,0,0,0.1));
}

.app-header h1 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.subtitle {
  color: var(--text-secondary);
  font-size: 14px;
}

/* 主内容区 */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 24px;
  padding-bottom: 40px;
}

/* 卡片通用样式 */
.card {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
  padding: 24px;
  transition: transform 0.2s, box-shadow 0.2s;
}

.input-card {
  border-top: 4px solid var(--primary-color);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.card-header h3 {
  font-size: 18px;
  font-weight: 600;
}

/* 首页工具网格 */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.tool-card {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 20px;
  display: flex;
  align-items: center;
  gap: 16px;
  cursor: pointer;
  transition: all 0.2s;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.tool-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-color);
}

.tool-icon {
  font-size: 32px;
  background: #F0F9FF;
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
}

.tool-info h4 {
  font-size: 16px;
  margin-bottom: 4px;
  color: var(--text-main);
}

.tool-info p {
  font-size: 12px;
  color: var(--text-secondary);
}

.btn-back {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 14px;
  cursor: pointer;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 0;
}

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

/* 表单元素 */
.form-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.full-width {
  grid-column: 1 / -1;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-label {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
}

.form-select, .form-input {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 16px; /* 防止iOS缩放 */
  background: #F9FAFB;
  transition: all 0.2s;
  appearance: none;
}

.form-select:focus, .form-input:focus {
  outline: none;
  border-color: var(--primary-color);
  background: #FFFFFF;
  box-shadow: 0 0 0 3px rgba(0, 102, 255, 0.1);
}

.input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.unit {
  position: absolute;
  right: 12px;
  color: var(--text-secondary);
  font-size: 14px;
  pointer-events: none;
}

.custom-input-row {
  margin-top: 12px;
  animation: slideDown 0.3s ease-out;
}

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}

.hidden {
  display: none !important;
}

/* 时间输入组 */
.time-inputs {
  display: flex;
  align-items: center;
  gap: 12px;
}

.time-field {
  flex: 1;
  position: relative;
}

.time-field .form-input {
  padding-right: 64px; /* Space for unit label + spinner */
}

.time-label {
  position: absolute;
  right: 32px; /* Move left to avoid native spinner */
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-secondary);
  font-size: 14px;
  pointer-events: none;
}

.time-separator {
  font-weight: 700;
  color: var(--text-secondary);
  font-size: 20px;
  margin-top: -4px;
}

/* 渐进速度输入修复 */
.progressive-wrapper .form-input {
  padding-right: 80px; /* Space for long unit + spinner */
}

.progressive-wrapper .unit {
  right: 32px; /* Move left of spinner */
}

.divider {
  grid-column: 1 / -1;
  height: 1px;
  background: var(--border-color);
  margin: 10px 0;
}

.section-title {
  grid-column: 1 / -1;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: -10px;
}

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

.action-buttons {
  display: flex;
  gap: 12px;
}

.btn {
  flex: 1;
  padding: 12px;
  border: none;
  border-radius: var(--radius-md);
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-primary {
  background: var(--primary-color);
  color: white;
  box-shadow: 0 4px 6px rgba(0, 102, 255, 0.2);
}

.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 6px 8px rgba(0, 102, 255, 0.3);
}

.btn-secondary {
  background: #EFF6FF;
  color: var(--primary-color);
}

.btn-secondary:hover {
  background: #DBEAFE;
}

/* 错误提示 */
.error-msg {
  background: #FEF2F2;
  border: 1px solid #FECACA;
  color: #B91C1C;
  padding: 12px;
  border-radius: var(--radius-md);
  margin-bottom: 16px;
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* 结果区域 */
.result-section {
  animation: fadeIn 0.5s ease-out;
  margin-top: 32px;
}

/* 心率页结果布局调整 */
#hrResultSection .stat-card.primary {
  margin-bottom: 32px;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
  gap: 12px;
  margin-bottom: 24px;
}

.stat-card {
  background: white;
  padding: 16px;
  border-radius: var(--radius-md);
  text-align: center;
  border: 1px solid var(--border-color);
}

.stat-card.primary {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
  color: white;
  border: none;
  box-shadow: 0 4px 6px rgba(0, 102, 255, 0.2);
}

.stat-card.primary .stat-label {
  color: rgba(255, 255, 255, 0.9);
  font-weight: 500;
}

.stat-card.primary .stat-value {
  color: white;
  font-size: 32px;
}

.stat-card.primary .stat-unit {
  color: rgba(255, 255, 255, 0.8);
}

.stat-label {
  font-size: 12px;
  color: var(--text-secondary);
  margin-bottom: 4px;
}

.stat-value {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.2;
}

.stat-unit {
  font-size: 12px;
  font-weight: 400;
  margin-left: 2px;
}

/* 表格样式 */
.table-container {
  overflow-x: auto;
  margin: -24px;
  margin-top: 0;
}

.pace-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

.pace-table th, .pace-table td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.pace-table th {
  background: #F9FAFB;
  font-weight: 600;
  color: var(--text-secondary);
  white-space: nowrap;
}

.pace-table tr:last-child td {
  border-bottom: none;
}

.table-input {
  width: 60px;
  padding: 4px 8px;
  border: 1px solid transparent;
  border-radius: 4px;
  background: transparent;
  font-family: inherit;
  font-size: inherit;
  transition: all 0.2s;
}

.table-input:hover {
  border-color: var(--border-color);
  background: #fff;
}

.table-input:focus {
  outline: none;
  border-color: var(--primary-color);
  background: #fff;
  box-shadow: 0 0 0 2px rgba(0, 102, 255, 0.1);
}

.table-input.invalid {
  border-color: var(--error-color);
  background: #FEF2F2;
  color: var(--error-color);
}

.card-footer {
  margin-top: 24px;
  padding-top: 16px;
  border-top: 1px solid var(--border-color);
  text-align: left; /* 改为左对齐 */
}

.formula-info {
  text-align: left; /* 强制左对齐 */
  max-width: 100%; /* 允许占满宽度 */
}

.formula-info h4 {
  font-size: 14px;
  margin-bottom: 8px;
  color: var(--text-main);
}

.formula-info p {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.6; /* 增加行高，提升阅读体验 */
  margin-bottom: 4px;
  white-space: normal; /* 允许自动换行 */
}

/* Tooltip 样式 */
.tooltip-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background-color: var(--text-secondary);
  color: white;
  font-size: 12px;
  margin-left: 4px;
  cursor: pointer;
  vertical-align: middle;
}

.tooltip-popup {
  position: absolute;
  background: #374151;
  color: white;
  padding: 8px 12px;
  border-radius: 6px;
  font-size: 12px;
  line-height: 1.4;
  max-width: 250px;
  z-index: 2000;
  pointer-events: none;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  opacity: 0;
  transition: opacity 0.2s ease;
}

.tooltip-popup.visible {
  opacity: 1;
}

/* 简单的倒三角箭头 */
.tooltip-popup::after {
  content: '';
  position: absolute;
  top: 100%;
  left: 50%;
  margin-left: -5px;
  border-width: 5px;
  border-style: solid;
  border-color: #374151 transparent transparent transparent;
}

/* 页脚 */
.app-footer {
  text-align: center;
  color: var(--text-secondary);
  font-size: 12px;
  padding: 24px 0;
  margin-top: auto;
}

/* 响应式调整 */
@media (max-width: 600px) {
  .app-header {
    padding: 20px 0 16px;
  }
  
  .card {
    padding: 16px;
  }
  
  .form-grid {
    grid-template-columns: 1fr;
  }
  
  .stat-label {
    margin-bottom: 0;
  }
  
  .stat-value {
    font-size: 18px;
  }
  
  .stat-card.primary .stat-value {
    font-size: 20px;
  }
}

/* 新增：Combo Select 样式 */
.combo-wrapper {
  position: relative;
}

.combo-wrapper .form-input {
  padding-right: 80px; /* 留出单位和下拉箭头的位置 */
}

.unit-text {
  position: absolute;
  right: 48px; /* 在箭头左侧 */
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-secondary);
  pointer-events: none;
  font-size: 14px;
}

.combo-select {
  position: absolute;
  right: 0;
  top: 0;
  width: 48px; /* 覆盖右侧箭头区域 */
  height: 100%;
  opacity: 0; /* 完全透明，但可点击 */
  cursor: pointer;
  z-index: 2;
}

.combo-arrow {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  pointer-events: none;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1;
}

/* 悬停时箭头变色，提示可点击 */
.combo-wrapper:hover .combo-arrow {
  color: var(--primary-color);
}

/* 心率区间样式 */
.hr-table th, .hr-table td {
  text-align: center;
}

.zone-tag {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 500;
}

.zone-1 { background: #F3F4F6; color: #4B5563; } /* 恢复 - 灰 */
.zone-2 { background: #DBEAFE; color: #1E40AF; } /* 燃脂 - 蓝 */
.zone-3 { background: #D1FAE5; color: #065F46; } /* 有氧 - 绿 */
.zone-4 { background: #FEF3C7; color: #92400E; } /* 乳酸 - 橙 */
.zone-5 { background: #FEE2E2; color: #991B1B; } /* 极限 - 红 */

/* 计划列表样式 - 新结构化设计 */
.plan-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.plan-week-card {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: #fff;
  box-shadow: var(--shadow-sm);
  transition: all 0.3s ease;
}

.plan-week-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  border-color: var(--primary-color);
}

.week-header-styled {
  background: linear-gradient(to right, #F0F9FF, #fff);
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 16px;
}

.week-badge {
  background: var(--primary-color);
  color: white;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 6px;
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  box-shadow: 0 2px 4px rgba(0, 102, 255, 0.2);
}

.week-target-text {
  font-weight: 600;
  color: var(--text-main);
  font-size: 16px;
}

.week-sessions-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr); /* 默认三列 */
  gap: 16px;
  padding: 20px;
  background: #fff;
}

.session-card {
  background: #F9FAFB;
  border-radius: 12px;
  padding: 16px;
  border: 1px solid transparent;
  transition: all 0.2s;
  display: flex;
  flex-direction: column;
}

.session-card:hover {
  background: #F0F7FF;
  border-color: #BAE6FD;
}

.session-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(0,0,0,0.05);
}

.day-tag {
  font-size: 12px;
  font-weight: 700;
  color: var(--text-secondary);
  text-transform: uppercase;
}

.duration-badge {
  font-size: 12px;
  color: var(--primary-color);
  background: rgba(0, 102, 255, 0.1);
  padding: 2px 8px;
  border-radius: 10px;
  font-weight: 500;
  white-space: nowrap;
}

.session-body {
  flex: 1;
  display: flex;
  align-items: center;
}

.session-main-text {
  margin: 0;
  font-size: 14px;
  color: var(--text-main);
  line-height: 1.5;
}

/* 课表卡片视觉优化 */
.interval-visual {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  width: 100%;
}

.interval-block {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 8px;
  font-weight: 600;
  font-size: 16px;
  width: 100%;
}

.run-pill {
  background: #DBEAFE;
  color: #1E40AF;
  padding: 8px 16px;
  border-radius: 8px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  width: 100%;
  box-sizing: border-box;
  font-weight: 700;
}

.walk-pill {
  background: #D1FAE5;
  color: #065F46;
  padding: 8px 16px;
  border-radius: 8px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  width: 100%;
  box-sizing: border-box;
  font-weight: 700;
}

.run-pill.large {
  font-size: 16px;
  justify-content: center;
}

.plus {
  display: none;
}

.repeat-badge {
  align-self: flex-start;
  background: #F3F4F6;
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 12px;
  margin-top: 4px;
}

/* 混合模式视觉 */
.mixed-visual {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  font-size: 13px;
}

.mixed-part {
  background: #fff;
  border: 1px solid var(--border-color);
  padding: 2px 6px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  gap: 2px;
}

.run-text {
  color: var(--primary-color);
  font-weight: 600;
}

.walk-text {
  color: var(--success-color);
  font-size: 12px;
}

/* 比赛模式视觉 */
.race-visual {
  width: 100%;
  text-align: center;
}

.race-pill {
  display: inline-block;
  background: linear-gradient(135deg, #FFD700 0%, #FFA500 100%);
  color: #fff;
  font-weight: 700;
  padding: 8px 16px;
  border-radius: 20px;
  box-shadow: 0 2px 4px rgba(255, 165, 0, 0.3);
}

/* 响应式调整 */
@media (max-width: 768px) {
  .week-sessions-grid {
    grid-template-columns: 1fr; /* 移动端单列堆叠 */
  }

  .week-header-styled {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
  
  .week-badge {
    font-size: 12px;
  }
  
  .week-target-text {
    font-size: 15px;
  }
}.status-tag {
  font-size: 12px;
  padding: 4px 8px;
  border-radius: 12px;
  background: #E0F2FE;
  color: #0284C7;
  font-weight: 500;
  float: right; /* 让状态标签浮动到右侧 */
}
/* 策略设置网格布局 */
.strategy-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

@media (max-width: 480px) {
  .strategy-grid {
    grid-template-columns: 1fr;
  }
}