:root {
  --primary: #3978b7;
  --primary-dark: #285e91;
  --background: #f4f8fc;
  --surface: #ffffff;
  --border: #dce7f0;
  --text: #253746;
  --muted: #687c8d;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 40px 20px;
  color: var(--text);
  background: var(--background);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.85;
}

.wrapper {
  width: min(860px, 100%);
  margin: 0 auto;
}

.ibox-content {
  padding: clamp(24px, 5vw, 52px);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  box-shadow: 0 18px 48px rgba(40, 94, 145, 0.12);
}

h2 {
  margin: 0 0 28px;
  color: var(--primary-dark);
  font-size: clamp(26px, 4vw, 36px);
  line-height: 1.25;
}

p {
  margin: 0;
  overflow-wrap: anywhere;
}

a {
  color: var(--primary);
}

@media (max-width: 600px) {
  body {
    padding: 16px 12px;
  }

  .ibox-content {
    padding: 22px 18px;
    border-radius: 14px;
  }
}