/* ===== 求学通 公共样式 ===== */
/* 依赖 design-tokens.css 中的 CSS 变量 */
:root {
  --primary: #1a56db;
  --primary-dark: #1e40af;
  --secondary: #047857;
  --cta: #1a56db;
  --success: #047857;
  --bg: #f8fafc;
  --card: #FFFFFF;
  --title: #1e293b;
  --text: #334155;
  --muted: #64748b;
  --border: #e2e8f0;
  --radius: 12px;
  --shadow: 0 2px 12px rgba(0,0,0,.06);
  --font: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif;
}

/* 基础重置 */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}
a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }

/* 布局 */
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 24px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all .25s ease;
}
.btn:hover { transform: translateY(-2px); box-shadow: 0 4px 16px rgba(0,0,0,.12); }
.btn-primary { background: var(--primary); color: #fff; }
.btn-cta { background: var(--cta); color: #fff; }
.btn-outline { background: #fff; border: 2px solid var(--primary); color: var(--primary); }
.btn-secondary { background: var(--bg); border: 1px solid var(--border); color: var(--text); }
.btn-lg { padding: 14px 32px; font-size: 16px; }
.btn-sm { padding: 6px 16px; font-size: 12px; border-radius: 6px; }

/* 头部导航 */
.header {
  background: #fff;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.logo-text {
  font-size: 20px;
  font-weight: 800;
  color: var(--primary-dark);
  display: flex;
  align-items: center;
  gap: 8px;
}
.logo-icon {
  width: 32px;
  height: 32px;
  background: var(--primary);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 800;
  font-size: 16px;
  flex-shrink: 0;
}
.nav { display: flex; gap: 4px; }
.nav a {
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 14px;
  color: var(--text);
  transition: all .2s;
  white-space: nowrap;
}
.nav a:hover, .nav a.active { background: #EEF2FF; color: var(--primary); }
.header-actions { display: flex; gap: 8px; align-items: center; }

/* 面包屑 */
.breadcrumb {
  font-size: 13px;
  color: var(--muted);
  padding: 16px 0 8px;
  max-width: 1200px;
  margin: 0 auto;
  padding-left: 20px;
  padding-right: 20px;
}
.breadcrumb a { color: var(--primary); }
.breadcrumb span { margin: 0 6px; }

/* 页面标题 */
.page-title {
  padding: 0 0 20px;
  max-width: 1200px;
  margin: 0 auto;
  padding-left: 20px;
  padding-right: 20px;
}
.page-title h1 { font-size: 28px; font-weight: 700; color: var(--title); }

/* 卡片 */
.card {
  background: var(--card);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: all .25s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: 0 8px 24px rgba(0,0,0,.1); }

/* 标签 */
.tag {
  display: inline-block;
  background: #EEF2FF;
  color: var(--primary);
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 10px;
  margin: 2px;
}
.tag-orange { background: #FFF7ED; color: var(--cta); }
.tag-green { background: #D1FAE5; color: var(--secondary); }

/* 表单 */
.input-group { margin-bottom: 20px; }
.input-group .label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  color: var(--title);
  margin-bottom: 8px;
}
.input-field {
  width: 100%;
  height: 44px;
  padding: 0 16px;
  font-size: 14px;
  font-family: var(--font);
  color: var(--title);
  background: #fff;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  outline: none;
  transition: border-color .2s;
}
.input-field:focus { border-color: var(--primary); }
textarea.input-field { height: auto; padding: 12px 16px; resize: vertical; min-height: 100px; }

/* 页脚 */
.footer {
  background: #1e293b;
  color: #D1D5DB;
  padding: 48px 0 24px;
  margin-top: 48px;
}
.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}
.footer-col h4 { font-size: 16px; font-weight: 600; color: #fff; margin-bottom: 16px; }
.footer-col a {
  display: block;
  font-size: 13px;
  color: #9CA3AF;
  padding: 4px 0;
  transition: color .2s;
}
.footer-col a:hover { color: #fff; }
.footer-bottom {
  text-align: center;
  font-size: 12px;
  color: #6B7280;
  padding-top: 24px;
  margin-top: 32px;
  border-top: 1px solid #374151;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
}

/* 响应式 */
.hamburger {
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--title);
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
}
@media (max-width: 768px) {
  .nav, .header-actions .btn-outline { display: none; }
  .hamburger { display: flex; }
}
@media (min-width: 769px) {
  .hamburger { display: none; }
}