/* 全局样式 */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f4f4f4;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

/* 容器样式 */
.container {
    background-color: #ffffff;
    border-radius: 15px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
    padding: 40px;
    width: 80%;
    max-width: 600px;
    animation: fadeIn 1s ease;
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    align-items: center;
}

/* 淡入动画 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 标题样式 */
h2 {
    text-align: center;
    color: #333;
    margin-bottom: 10px;
    animation: slideInDown 1s ease;
}

/* 说明文字样式 */
.instructions {
    text-align: center;
    color: #666;
    margin-bottom: 20px;
    animation: fadeInLeft 1s ease;
}

/* 从上向下滑入动画 */
@keyframes slideInDown {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* 表单组样式 */
.form-group {
    margin-bottom: 25px;
    width: 100%;
    animation: fadeInLeft 1s ease;
}

/* 从左向右淡入动画 */
@keyframes fadeInLeft {
    from {
        transform: translateX(-20px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* 表单组标签样式 */
.form-group label {
    display: block;
    margin-bottom: 10px;
    font-weight: 600;
    color: #555;
}

/* 表单输入框样式 */
.form-group input[type="text"],
.form-group input[type="email"],
.form-group input[type="file"] {
    width: calc(100% - 30px);
    padding: 15px;
    border: 1px solid #ccc;
    border-radius: 8px;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    font-size: 16px;
}

/* 输入框聚焦样式 */
.form-group input[type="text"]:focus,
.form-group input[type="email"]:focus {
    border-color: #007BFF;
    outline: none;
    box-shadow: 0 0 5px rgba(0, 123, 255, 0.3);
}

/* 单选框样式 */
.form-group input[type="radio"] {
    margin-right: 10px;
}

/* 单选框组横向排列 */
.radio-group.horizontal {
    display: flex;
    align-items: center;
}

/* 按钮样式 */
button {
    background-color: #007BFF;
    color: white;
    padding: 15px 30px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.3s ease;
    font-size: 16px;
    font-weight: 600;
    width: 100%;
    animation: fadeInUp 1s ease;
}

/* 从下向上淡入动画 */
@keyframes fadeInUp {
    from {
        transform: translateY(20px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* 按钮悬停样式 */
button:hover {
    background-color: #0056b3;
    transform: scale(1.05);
}