/* 全局统一盒模型 */
*,
*::before,
*::after {
    box-sizing: border-box;
}


body {
    font-family: sans-serif;
    max-width: 600px;
    margin: auto;
    padding: 20px;
}

input,
select {
    display: block;
    /* 块级元素 */
    width: 100%;
    /* 占满父容器宽度 */
    padding: 8px;
    margin: 10px 0;
    /* 只有上下留白，左右无留白 */
    font-size: 16px;
    border: 1px solid #ccc;
    border-radius: 4px;
}

input.missing {
    border-color: red;
    background-color: #ffe6e6;
}

.section {
    margin-top: 20px;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 8px;
}

button {
    font-size: 18px;
    padding: 10px 20px;
    background-color: #2e86de;
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
}

button:hover {
    background-color: #1c6ab9;
}

pre {
    background: #f9f9f9;
    padding: 10px;
    white-space: pre-wrap;
}