/* base.css - 重置+变量+工具类（全局加载） */

/* ===== CSS变量 ===== */
:root {
  --primary: #1B3A4B;
  --secondary: #E63946;
  --dark-bg: #0F212B;
  --page-bg: #F0F4F8;
  --text-white: #FFFFFF;
  --text-dark: #333333;
  --text-gray: #666666;
  --border-color: #C8D5E0;
  --font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  --container-max: 1200px;
  --container-padding: 20px;
}

/* ===== 重置 ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  color: var(--text-dark);
  background-color: var(--page-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  text-decoration: none;
  color: inherit;
  transition: color 0.3s ease;
}

ul, ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
}

/* ===== 工具类 ===== */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.flex {
  display: -webkit-box;
  display: -webkit-flex;
  display: flex;
}

.flex-wrap {
  -webkit-flex-wrap: wrap;
  flex-wrap: wrap;
}

.items-center {
  -webkit-box-align: center;
  -webkit-align-items: center;
  align-items: center;
}

.justify-between {
  -webkit-box-pack: justify;
  -webkit-justify-content: space-between;
  justify-content: space-between;
}

.justify-center {
  -webkit-box-pack: center;
  -webkit-justify-content: center;
  justify-content: center;
}

.grid {
  display: -webkit-box;
  display: -webkit-flex;
  display: flex;
  -webkit-flex-wrap: wrap;
  flex-wrap: wrap;
}

.hidden { display: none; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-block;
  padding: 12px 32px;
  border-radius: 4px;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  border: none;
  font-family: var(--font-family);
}

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

.btn-primary:hover {
  background-color: #c1121f;
}

.btn-outline {
  background-color: transparent;
  color: var(--secondary);
  border: 2px solid var(--secondary);
}

.btn-outline:hover {
  background-color: var(--secondary);
  color: var(--text-white);
}

/* ===== 间距 ===== */
.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mt-4 { margin-top: 32px; }
.mt-5 { margin-top: 48px; }

.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }
.mb-4 { margin-bottom: 32px; }
.mb-5 { margin-bottom: 48px; }

.pt-1 { padding-top: 8px; }
.pt-2 { padding-top: 16px; }
.pt-3 { padding-top: 24px; }
.pt-4 { padding-top: 32px; }
.pt-5 { padding-top: 48px; }

.pb-1 { padding-bottom: 8px; }
.pb-2 { padding-bottom: 16px; }
.pb-3 { padding-bottom: 24px; }
.pb-4 { padding-bottom: 32px; }
.pb-5 { padding-bottom: 48px; }

/* ===== 动画 ===== */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in {
  animation: fadeIn 0.6s ease forwards;
}

/* ===== 滚动条 ===== */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--page-bg);
}

::-webkit-scrollbar-thumb {
  background: var(--primary);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: #0F212B;
}

/* ===== 选择文字颜色 ===== */
::selection {
  background-color: var(--secondary);
  color: var(--text-white);
}