body {
      margin: 0;
      font-family: "Helvetica Neue", sans-serif;
      background-color: #f0f3f8;
      color: #2a2a3c;
      padding: 1rem 1.5rem 3rem;
      line-height: 1.6;
      max-width: 800px;
      margin-left: auto;
      margin-right: auto;
    }

    header {
  position: relative; /* 新增，建立定位上下文 */
  display: flex;
  align-items: center;
  padding: 1rem 0;
}

button.back-btn {
  position: relative; /* 新增，确保层级正确 */
  z-index: 10;        /* 新增，保证按钮在标题上层 */
  background-color: #f0f3f8;
  border: none;
  color: #2a3a62;
  font-size: 1.1rem;
  cursor: pointer;
  padding: 0.3rem 0.8rem;
  border-radius: 6px;
  transition: background-color 0.25s ease;
  user-select: none;
  margin-left: 0;
  padding-left: 0.1rem;
}

button.back-btn:hover {
  background-color: #e0e6f1;
}

h1 {
  position: absolute;       /* 修改，改成绝对定位 */
  left: 50%;               /* 横向居中 */
  transform: translateX(-50%);
  margin: 0;
  font-weight: 700;
  font-size: 1.6rem;
  color: #2a3a62;
  letter-spacing: 0.8px;
  pointer-events: none;    /* 可选，防止遮挡按钮 */
}


    h2 {
      color: #2a3a62;
      font-weight: 600;
      margin-top: 2rem;
      margin-bottom: 0.8rem;
      font-size: 1.25rem;
    }

    p {
      margin-bottom: 1rem;
      font-size: 1rem;
      color: #4a4a5a;
    }

    footer {
      text-align: center;
      font-size: 0.85rem;
      color: #888a94;
      margin-top: 4rem;
      user-select: none;
    }

    @media (max-width: 600px) {
      body {
        padding: 1rem 1rem 2rem;
      }
    }