/* 全局样式重置 */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f4f4f9;
    color: #333;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    min-height: 100vh;
}

/* 主容器 */
.container {
    width: 100%;
    max-width: 800px;
    background: white;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    margin: 20px;
    border-radius: 10px;
    overflow: hidden;
}

/* 头部样式 */
header {
    background-color: #007BFF;
    color: white;
    padding: 20px;
    text-align: center;
}

header h1 { margin: 0; font-size: 2rem; }
header p { margin: 10px 0 0; opacity: 0.8; }

/* 内容区域 */
main { padding: 20px; }

/* 卡片样式 */
.card {
    background: #fff;
    border: 1px solid #e1e1e1;
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 20px;
    transition: transform 0.2s;
}

.card:hover {
    transform: translateY(-5px); /* 鼠标放上去会上浮 */
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

/* 按钮样式 */
button {
    background-color: #28a745;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    transition: background 0.3s;
}

button:hover {
    background-color: #218838;
}

/* 底部 */
footer {
    text-align: center;
    padding: 20px;
    background: #f8f9fa;
    border-top: 1px solid #e1e1e1;
}