/* 卡丁车数据分析 — ICP 合规壳静态站点
 * 设计原则：清爽、专业、避免任何"花哨"以免触发审核质疑
 */

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

body {
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: #2c3e50;
  background: #f8f9fb;
  -webkit-font-smoothing: antialiased;
}

a {
  color: #2563eb;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* 顶部导航 */
.nav {
  background: #fff;
  border-bottom: 1px solid #e5e7eb;
  padding: 0 24px;
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
}

.brand {
  font-size: 20px;
  font-weight: 600;
  color: #1f2937;
  letter-spacing: 0.5px;
}

.nav-links {
  display: flex;
  gap: 28px;
  font-size: 15px;
}

.nav-links a {
  color: #4b5563;
}

.nav-links a:hover {
  color: #2563eb;
  text-decoration: none;
}

/* 主内容区 */
main {
  max-width: 800px;
  margin: 0 auto;
  padding: 48px 24px 80px;
}

.hero {
  text-align: center;
  padding: 32px 0 48px;
  border-bottom: 1px solid #e5e7eb;
  margin-bottom: 40px;
}

.hero h1 {
  font-size: 36px;
  font-weight: 700;
  color: #111827;
  margin-bottom: 16px;
  letter-spacing: -0.3px;
}

.hero .subtitle {
  font-size: 18px;
  color: #6b7280;
  max-width: 600px;
  margin: 0 auto;
}

.coming-soon {
  display: inline-block;
  margin-top: 24px;
  padding: 8px 20px;
  background: #eff6ff;
  color: #1e40af;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 500;
}

/* 内容卡片 */
section {
  margin-bottom: 40px;
}

section h2 {
  font-size: 24px;
  font-weight: 600;
  color: #1f2937;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid #e5e7eb;
}

section h3 {
  font-size: 18px;
  font-weight: 600;
  color: #374151;
  margin-top: 24px;
  margin-bottom: 8px;
}

section p {
  margin-bottom: 12px;
  color: #4b5563;
}

section ul, section ol {
  margin: 12px 0 16px 24px;
  color: #4b5563;
}

section li {
  margin-bottom: 6px;
}

section table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 14px;
}

section th, section td {
  padding: 10px 14px;
  text-align: left;
  border: 1px solid #e5e7eb;
}

section th {
  background: #f3f4f6;
  font-weight: 600;
  color: #1f2937;
}

/* 功能卡片栅格 */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
  margin: 24px 0;
}

.feature-card {
  background: #fff;
  border: 1px solid #e5e7eb;
  border-radius: 8px;
  padding: 20px;
}

.feature-card .feat-title {
  font-size: 16px;
  font-weight: 600;
  color: #111827;
  margin-bottom: 8px;
}

.feature-card .feat-desc {
  font-size: 14px;
  color: #6b7280;
  line-height: 1.6;
}

/* 联系方式块 */
.contact-block {
  background: #fff;
  border: 1px solid #e5e7eb;
  border-radius: 8px;
  padding: 24px;
  margin: 16px 0;
}

.contact-block dt {
  font-weight: 600;
  color: #374151;
  margin-top: 12px;
}

.contact-block dt:first-child {
  margin-top: 0;
}

.contact-block dd {
  margin-left: 0;
  color: #4b5563;
  margin-bottom: 4px;
}

/* 底部 */
footer {
  background: #fff;
  border-top: 1px solid #e5e7eb;
  padding: 32px 24px;
  text-align: center;
  font-size: 13px;
  color: #6b7280;
}

footer .footer-inner {
  max-width: 800px;
  margin: 0 auto;
}

footer p {
  margin-bottom: 6px;
}

footer .icp {
  margin-top: 12px;
  font-size: 13px;
}

footer a {
  color: #6b7280;
}

/* 响应式 */
@media (max-width: 640px) {
  .nav-inner { height: 56px; }
  .brand { font-size: 18px; }
  .nav-links { gap: 16px; font-size: 14px; }
  .hero h1 { font-size: 28px; }
  .hero .subtitle { font-size: 16px; }
  main { padding: 32px 16px 60px; }
  section h2 { font-size: 20px; }
  section table { font-size: 13px; }
  section th, section td { padding: 8px 10px; }
}