body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  line-height: 1.6;
  background-color: #f4f4f4;
}

header {
  background-color: #e0e0e0; /* 柔和的浅灰色 */
  color: #333;
  padding: 10px 20px;
  text-align: left;
}

.header-red {
  background-color: #ff0000;
  color: #333;
  padding: 10px 20px;
  text-align: left;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

header h1 {
  margin: 0;
  font-size: 1.5em;
}

header h2.right {
  margin: 0;
  font-size: 1em;
}

main {
  padding: 20px;
  background-color: #fff;
  margin: 20px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
  border-radius: 0; /* 直角矩形 */
}

.dropdown-btn {
  background-color: #e0e0e0; /* 按钮背景色 */
  color: #333;
  padding: 10px 20px;
  border: none;
  cursor: pointer;
  width: 100%; /* 一整行 */
  text-align: left;
  font-size: 1em;
  border-radius: 5px;
  margin-bottom: 10px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: background-color 0.3s;
}

.dropdown-btn:hover {
  background-color: #d0d0d0; /* 悬停变色效果 */
}

.dropdown-btn .arrow {
  font-size: 1em;
  transition: transform 0.3s;
}

.dropdown-content {
  display: none;
  background-color: #f9f9f9;
  padding: 10px;
  border-radius: 5px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease-out;
}

.dropdown-content.show {
  display: block;
  max-height: 50000px; /* 根据内容调整 */
  animation: slideDown 0.3s ease-out, slideUp 0.3s ease-out reverse;
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideUp {
  from {
    opacity: 1;
    transform: translateY(0);
  }
  to {
    opacity: 0;
    transform: translateY(-10px);
  }
}

.rotate {
  transform: rotate(180deg);
}

nav ul.menu {
  list-style-type: none;
  padding: 0;
  margin: 0;
}

nav ul.menu li {
  margin: 0;
  padding: 5px 0;
}

nav ul.menu li a {
  text-decoration: none;
  color: #333; /* 深灰色文字 */
  padding: 5px 0;
  display: block;
}

nav ul.menu li a:hover {
  background-color: #ddd; /* 悬停变色效果 */
  border-radius: 5px; /* 圆角矩形 */
}

nav ul.menu li a::before {
  content: " | ";
  display: inline-block;
  margin-right: 10px;
  color: #333; /* 与文本颜色一致 */
  font-size: 1.2em; /* 变长 */
}

.warning {
  color: #fff;
  background-color: #ff4d4d; /* 红色背景 */
  padding: 10px;
  border-radius: 5px;
  display: flex;
  align-items: center;
}

.warning .icon {
  display: inline-block;
  width: 20px;
  height: 20px;
  background-color: #ff4d4d;
  color: #fff;
  border-radius: 50%;
  text-align: center;
  line-height: 20px;
  margin-right: 10px;
  font-weight: bold;
  font-size: 14px;
}

.divider {
  border: 0;
  height: 1px;
  background: #e0e0e0;
  margin: 20px 0;
}

section {
  margin-bottom: 20px;
}

nav ul li a.button2 {
  display: inline-block;
  text-decoration: none;
  color: #333; /* 深灰色文字 */
  background-color: #f0f0f0; /* 柔和的浅灰色按钮 */
  padding: 10px 20px;
  border-radius: 5px;
  transition: background-color 0.3s;
}

nav ul li a.button3 {
  display: inline-block;
  text-decoration: none;
  color: #333; /* 深灰色文字 */
  background-color: #f0f0f0; /* 柔和的浅灰色按钮 */
  padding: 10px 20px;
  border-radius: 5px;
  transition: background-color 0.3s;
  padding: 10px;
  border-radius: 5px;
  display: flex;
  align-items: center;
}

nav ul li a.button2:hover {
  background-color: #d0d0d0; /* 悬停效果 */
}

nav ul {
  list-style-type: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column; /* 每个按钮换行 */
  gap: 0px; /* 增加按钮之间的间距 */
}