/* 通用样式 */
body {
    font-family: Arial, sans-serif;
    background-color: #f7f7f7;
    margin: 0;
    padding: 0;
    text-align: center;
    padding-top: 70px; /* 增加顶部间距以避免内容与导航栏重叠 */
}

h1, h2 {
    color: #333;
}

.button {
    display: block; /* 修改为块级元素，使每个按钮独占一行 */
    width: 40%; /* 按钮宽度 */
    margin: 10px auto; /* 水平居中，添加上下间距 */
    padding: 5px 20px; /* 减少垂直填充，使按钮更扁平 */
    border-radius: 20px; /* 保持圆角样式 */
    text-decoration: none;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
}

/* 按钮样式 */
.button:hover {
    display: block;
    width: 40%;
    margin: 10px auto;
    padding: 5px 20px;
    border-radius: 20px;
    text-decoration: none;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
}

.login-button {
    background-color: green;
    color: white;
    border: none;
}

.login-button:hover {
    background-color: darkgreen;
    color: white;
    border: none;
}

.register-button {
    background-color: white;
    color: blue;
    border: 2px solid blue;
}

.register-button:hover {
    background-color: #EAEAEA;
    color: blue;
    border: 2px solid blue;
}

.logout-button {
    background-color: red;
    color: white;
    border: none;
}

.logout-button:hover {
    background-color: darkred;
    color: white;
    border: none;
}

/* 页脚样式 */
.footer {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 10px 20px;
    position: fixed;
    bottom: 0;
    width: 100%;
}

/* 导航栏样式 */
header {
    width: 100%;
    background-color: #333;
    color: white;
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1000;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.5); /* 添加阴影效果 */
}

nav ul {
    list-style-type: none;
    padding: 0;
    margin: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

nav li {
    flex-grow: 1;
    text-align: center;
}

nav a {
    color: white;
    text-decoration: none;
    display: block;
    padding: 10px 20px;
    font-size: 1.00em; /* 增大字体大小 */
}

main {
    padding-top: 70px; /* 增加顶部间距以避免内容与导航栏重叠 */
}