/* 大数据系统 - 全局样式 */
* { margin: 0; padding: 0; box-sizing: border-box; }
:root {
  --navy: #1a365d;
  --navy-2: #2c5282;
  --blue: #3182ce;
  --bg: #f4f7fb;
  --card: #ffffff;
  --line: #e2e8f0;
  --text: #1f2937;
  --muted: #64748b;
  --red: #dc3545;
  --amber: #d97706;
  --green: #16a34a;
}
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}
.topbar {
  background: linear-gradient(135deg, #16305a 0%, #1a365d 60%, #2c5282 100%);
  color: #fff;
  padding: 18px 20px;
  text-align: center;
  box-shadow: 0 2px 12px rgba(26, 54, 93, .25);
}
.topbar h1 { font-size: 22px; letter-spacing: 2px; font-weight: 700; }
.topbar p { font-size: 12px; opacity: .75; margin-top: 4px; letter-spacing: 1px; }
.wrap { max-width: 720px; margin: 0 auto; padding: 20px 16px 48px; }
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 24px;
  box-shadow: 0 2px 10px rgba(15, 40, 80, .06);
}
.footer {
  text-align: center; font-size: 12px; color: #94a3b8;
  padding: 24px 0 32px;
}