/* 全局基础：统一盒模型和默认 margin/padding 清零 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* 页面基础排版：字体、背景色、行高 */
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, 'Helvetica Neue', Arial, sans-serif;
  background: #f5f7fa;
  color: #333;
  line-height: 1.6;
}

/* 页面主容器：居中布局，统一最大宽度和内边距 */
.container {
  max-width: 1300px;
  margin: 0 auto;
  padding: 20px;
}

/* 页面标题：统一字号和间距，颜色由各页面自己定义 */
h1 {
  font-size: 2.2em;
  margin-bottom: 8px;
}

/* 通用下拉组件外层：负责定位箭头，并通过变量支持不同场景改色 */
.select-field {
  position: relative;
  width: 100%;
  --select-arrow-color: #2e7d32;
  --select-arrow-active-color: #256b29;
}

/* 自定义下拉箭头：保留原生 select 交互，只替换右侧视觉箭头 */
.select-field::after {
  content: '';
  position: absolute;
  top: 50%;
  right: 20px;
  width: 10px;
  height: 10px;
  border-right: 2px solid var(--select-arrow-color);
  border-bottom: 2px solid var(--select-arrow-color);
  transform: translateY(-65%) rotate(45deg);
  pointer-events: none;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.select-field:hover::after,
.select-field:focus-within::after {
  border-color: var(--select-arrow-active-color);
}

.select-field:focus-within::after {
  transform: translateY(-55%) rotate(45deg);
}

/* 通用下拉本体：统一四边内边距，并给右侧箭头留出空间 */
.select-field > select {
  width: 100%;
  padding: 12px 48px 12px 15px;
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  background-image: none;
}

/* 兼容旧版 IE / Edge 的默认展开箭头 */
.select-field > select ::-ms-expand {
  display: none;
}