/* ====== 全局字体设置 ====== */
html {
  font-family: "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei",
    sans-serif;
  line-height: 1.6;
  color: #333;
  font-size: 16px; /* 基础字体大小 */
}

body {
  margin: 0;
  padding: 0;
  background-color: #fff;
}

/* ====== 标题字体系统 ====== */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei",
    sans-serif;
  font-weight: 700;
  color: #fff;
  margin: 0;
  line-height: 1.2;
}

h1 {
  font-size: 2.5rem;
} /* 40px */
h2 {
  font-size: 2rem;
} /* 32px */
h3 {
  font-size: 1.75rem;
} /* 28px */
h4 {
  font-size: 1.5rem;
} /* 24px */
h5 {
  font-size: 1.25rem;
} /* 20px */
h6 {
  font-size: 1rem;
} /* 16px */

/* ====== 正文及辅助字体 ====== */
p {
  margin: 0;
  font-size: 1rem; /* 16px */
}

a {
  color: #59ccab;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

strong,
b {
  font-weight: 700;
}

em,
i {
  font-style: italic;
}

/* ====== 响应式字体 ====== */
@media (max-width: 1200px) {
  h1 {
    font-size: 2.25rem;
  }
  h2 {
    font-size: 1.875rem;
  }
  h3 {
    font-size: 1.5rem;
  }
  h4 {
    font-size: 1.25rem;
  }
  h5 {
    font-size: 1.125rem;
  }
  h6 {
    font-size: 1rem;
  }
}

@media (max-width: 768px) {
  html {
    font-size: 14px;
  }
  h1 {
    font-size: 2rem;
  }
  h2 {
    font-size: 1.75rem;
  }
  h3 {
    font-size: 1.5rem;
  }
  h4 {
    font-size: 1.25rem;
  }
  h5 {
    font-size: 1.125rem;
  }
  h6 {
    font-size: 1rem;
  }
}

@media (max-width: 480px) {
  html {
    font-size: 13px;
  }
  h1 {
    font-size: 1.75rem;
  }
  h2 {
    font-size: 1.5rem;
  }
  h3 {
    font-size: 1.25rem;
  }
  h4 {
    font-size: 1.125rem;
  }
  h5 {
    font-size: 1rem;
  }
  h6 {
    font-size: 0.875rem;
  }
}