/* base.css — 重置+变量+工具类（全局加载） */

/* === CSS Variables === */
:root {
  --color-primary: #1B4D3E;
  --color-accent: #D4A017;
  --color-dark: #0F2E25;
  --color-bg: #F0F4F2;
  --color-white: #FFFFFF;
  --color-text: #333333;
  --color-text-secondary: #666666;
  --color-border: #C8D5CF;
  --font-display: "Inter", "Helvetica Neue", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Inter", -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Fira Code", monospace;
  --container-max: 1200px;
  --container-padding: 24px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --transition-fast: 0.1s;
  --transition-normal: 0.3s;
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  -ms-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.75;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
  border: none;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-accent);
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 500;
  line-height: 1.3;
  color: var(--color-text);
}

h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.25rem; }

p {
  margin-bottom: 1em;
}

ul, ol {
  list-style: none;
}

/* === Utility Classes === */
.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; }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

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

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

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

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

.grid {
  display: -webkit-box;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-flex-wrap: wrap;
  -ms-flex-wrap: wrap;
  flex-wrap: wrap;
  margin: 0 -12px;
}

.grid-item {
  -webkit-box-flex: 1;
  -webkit-flex: 1;
  -ms-flex: 1;
  flex: 1;
  padding: 0 12px;
}

/* === Spacing === */
.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; }

/* === Color Utilities === */
.bg-primary { background-color: var(--color-primary); }
.bg-dark { background-color: var(--color-dark); }
.bg-white { background-color: var(--color-white); }
.bg-accent { background-color: var(--color-accent); }
.text-white { color: var(--color-white); }
.text-secondary { color: var(--color-text-secondary); }
.text-accent { color: var(--color-accent); }