/* ========== 全局变量 ========== */
:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #dbeafe;
  --accent: #10b981;
  --accent-light: #d1fae5;
  --text-main: #1f2937;
  --text-sub: #6b7280;
  --text-light: #9ca3af;
  --bg-page: #f8fafc;
  --bg-card: #ffffff;
  --border: #e5e7eb;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 12px 32px rgba(37, 99, 235, 0.12);
  --radius: 12px;
  --radius-sm: 8px;
  --max-width: 1160px;
  --nav-height: 64px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC',
    'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  color: var(--text-main);
  background: var(--bg-page);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
ul, li { list-style: none; }
img { max-width: 100%; display: block; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }
input { font-family: inherit; outline: none; }

/* ========== 布局容器 ========== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
  width: 100%;
}

.section { padding: 64px 0; }
.section-title {
  font-size: 28px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 8px;
  color: var(--text-main);
}
.section-subtitle {
  text-align: center;
  color: var(--text-sub);
  font-size: 15px;
  margin-bottom: 44px;
}

/* ========== 导航栏 ========== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.navbar .container {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 19px;
  font-weight: 700;
  color: var(--primary);
}
.nav-logo .logo-mark {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
}
.nav-logo-img {
  height: 40px;
  width: auto;
  display: block;
}
.nav-menu { display: flex; align-items: center; gap: 4px; }
.nav-menu a {
  padding: 8px 18px;
  border-radius: 8px;
  color: var(--text-sub);
  font-size: 15px;
  font-weight: 500;
  transition: all 0.2s;
}
.nav-menu a:hover { color: var(--primary); background: var(--primary-light); }
.nav-menu a.active { color: var(--primary); background: var(--primary-light); font-weight: 600; }

/* 导航登录按钮 */
.nav-login {
  padding: 8px 18px !important;
  border-radius: 8px !important;
  font-size: 14px !important;
  font-weight: 600 !important;
  border: 1.5px solid var(--primary) !important;
  color: var(--primary) !important;
  margin-left: 6px;
  transition: all 0.2s !important;
}
.nav-login:hover { background: var(--primary-light) !important; }
.nav-login-pl {
  background: var(--primary) !important;
  color: #fff !important;
  border-color: var(--primary) !important;
}
.nav-login-pl:hover { background: var(--primary-dark) !important; }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
}
.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--text-main);
  border-radius: 2px;
  transition: all 0.3s;
}

/* ========== 按钮 ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 600;
  transition: all 0.2s;
  white-space: nowrap;
}
.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4); }
.btn-outline {
  background: #fff;
  color: var(--primary);
  border: 1.5px solid var(--primary);
}
.btn-outline:hover { background: var(--primary-light); }
.btn-ghost {
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
  border: 1.5px solid rgba(255, 255, 255, 0.6);
}
.btn-ghost:hover { background: rgba(255, 255, 255, 0.25); }
.btn-sm { padding: 8px 18px; font-size: 14px; }
.btn:disabled,
.btn[disabled] {
  background: #e5e7eb;
  color: #9ca3af;
  border-color: #e5e7eb;
  box-shadow: none;
  cursor: not-allowed;
  transform: none;
}

/* ========== 页脚 ========== */
.footer {
  background: #111827;
  color: #d1d5db;
  padding: 48px 0 24px;
  margin-top: 40px;
}
.footer-top {
  display: flex;
  flex-wrap: wrap;
  gap: 40px;
  justify-content: space-between;
  padding-bottom: 32px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}
.footer-brand { max-width: 320px; }
.footer-brand .nav-logo { color: #fff; margin-bottom: 14px; }
.footer-brand p { color: #9ca3af; font-size: 14px; line-height: 1.7; }
.footer-links { display: flex; gap: 56px; flex-wrap: wrap; }
.footer-col h4 { color: #fff; font-size: 15px; margin-bottom: 16px; }
.footer-col a {
  display: block;
  color: #9ca3af;
  font-size: 14px;
  margin-bottom: 10px;
  transition: color 0.2s;
}
.footer-col a:hover { color: #fff; }
.footer-disclaimer {
  margin-top: 24px;
  padding: 16px 20px;
  background: rgba(255, 255, 255, 0.04);
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: #9ca3af;
  line-height: 1.7;
}
.footer-bottom {
  text-align: center;
  padding-top: 24px;
  font-size: 13px;
  color: #6b7280;
}
.footer-icp {
  display: inline-block;
  margin-top: 6px;
  color: #6b7280;
  transition: color 0.2s;
}
.footer-icp:hover { color: #9ca3af; }

/* ========== 通用状态（加载/空） ========== */
.state-box {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-sub);
  font-size: 15px;
}
.state-box .state-icon { font-size: 40px; margin-bottom: 12px; opacity: 0.5; }
.spinner {
  width: 34px;
  height: 34px;
  border: 3px solid var(--primary-light);
  border-top-color: var(--primary);
  border-radius: 50%;
  margin: 0 auto 14px;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ========== 响应式 ========== */
@media (max-width: 768px) {
  .section { padding: 44px 0; }
  .section-title { font-size: 23px; }
  .nav-toggle { display: flex; }
  .nav-menu {
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: #fff;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-md);
    padding: 8px;
    display: none;
  }
  .nav-menu.open { display: flex; }
  .nav-menu a { padding: 14px 18px; border-radius: 8px; }
  .nav-login { margin-left: 0; text-align: center; }
  .footer-top { flex-direction: column; gap: 28px; }
  .footer-links { gap: 32px; }
}