* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "微软雅黑", SimHei, sans-serif;
}
:root {
    --red-main: #c8161d;
    --red-light: #e63946;
    --white: #ffffff;
    --gray: #f5f5f5;
    --text-color: #333333;
}
/* --- 全局滚动偏移 --- */
html {
    /* 告诉浏览器锚点跳转时，要在顶部留出 100px 的空白 */
    /* 导航栏高，可以把 100px 改成 120px */
    scroll-padding-top: 100px;
    scroll-behavior: smooth; /* 确保点击时有平滑滚动效果 */
}
body {
    background-color: var(--white);
    color: var(--text-color);
    line-height: 1.8;
}
/* 导航栏 */
header {
    background-color: var(--white);
    border-bottom: 1px solid #eee;
    position: sticky;
    top: 0;
    z-index: 999;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.nav-container {
    width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 20px;
}
.logo-container {
    display: flex;
    align-items: center;
}
.logo-img {
    height: 50px;
    margin-right: 15px;
}
.logo-text {
    color: var(--red-main);
    font-size: 20px;
    font-weight: bold;
    white-space: nowrap;
}
.nav-menu a {
    color: var(--text-color);
    text-decoration: none;
    margin-left: 30px;
    font-size: 16px;
    transition: 0.3s;
}
.nav-menu a:hover {
    color: var(--red-main);
}

/* ====================== 核心：可自定义横幅 ====================== */
/* 1. 在这里替换你的背景图片链接 */
.banner {
    width: 100%;
    height: 500px;
    background: url('/static/img/banner1.webp') center/cover no-repeat;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: var(--white);
}
/* =============================================================== */

.banner h1 {
    font-size: 48px;
    margin-bottom: 20px;
    text-shadow: 0 2px 8px rgba(0,0,0,0.3);
}
.banner p {
    font-size: 20px;
    max-width: 800px;
    margin: 0 auto;
}
/* 通用容器 */
.container {
    width: 1200px;
    margin: 80px auto;
    padding: 0 20px;
}
.title-box {
    text-align: center;
    margin-bottom: 50px;
}
.title-box h2 {
    font-size: 32px;
    color: var(--red-main);
    position: relative;
    display: inline-block;
    padding-bottom: 15px;
}
.title-box h2::after {
    content: '';
    width: 80px;
    height: 3px;
    background-color: var(--red-main);
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    bottom: 0;
}
/* 服务概述 */
.about-text {
    background: var(--gray);
    padding: 40px;
    border-radius: 10px;
    font-size: 17px;
}
/* 服务模块 */
.module-wrap {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}
.module-card {
    background: var(--white);
    border: 1px solid #eee;
    border-left: 5px solid var(--red-main);
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    transition: 0.3s;
}
.module-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(200,22,29,0.15);
}
.module-card h3 {
    color: var(--red-main);
    font-size: 22px;
    margin-bottom: 20px;
}
.module-card ul {
    list-style: none;
}
.module-card li {
    margin-bottom: 12px;
    padding-left: 20px;
    position: relative;
}
.module-card li::before {
    content: '●';
    color: var(--red-main);
    position: absolute;
    left: 0;
}
/* 核心优势 */
.advantage-wrap {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
}
.advantage-card {
    text-align: center;
    padding: 30px 20px;
    background: linear-gradient(135deg, var(--red-main), var(--red-light));
    color: var(--white);
    border-radius: 10px;
}
.advantage-card h4 {
    font-size: 20px;
    margin-bottom: 15px;
}
/* 联系我们表单 */
.contact-section {
    background: var(--gray);
    padding: 60px 40px;
    border-radius: 12px;
}
.contact-form {
    max-width: 700px;
    margin: 0 auto;
}
.form-item {
    margin-bottom: 25px;
}
.form-item label {
    display: block;
    font-size: 16px;
    font-weight: bold;
    color: var(--red-main);
    margin-bottom: 8px;
}
.form-item input,
.form-item textarea {
    width: 100%;
    padding: 14px 16px;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 16px;
    outline: none;
    transition: 0.3s;
}
.form-item input:focus,
.form-item textarea:focus {
    border-color: var(--red-main);
    box-shadow: 0 0 0 2px rgba(200,22,29,0.2);
}
.form-item textarea {
    height: 140px;
    resize: vertical;
}
.submit-btn {
    width: 100%;
    padding: 16px;
    background-color: var(--red-main);
    color: var(--white);
    border: none;
    border-radius: 6px;
    font-size: 18px;
    font-weight: bold;
    cursor: pointer;
    transition: 0.3s;
}
.submit-btn:hover {
    background-color: #a81217;
}
/* 底部 */
footer {
    background-color: var(--red-main);
    color: var(--white);
    text-align: center;
    padding: 40px 0;
    margin-top: 50px;
}
/* 手机端适配 */
@media (max-width: 768px) {
    .nav-container, .container {
        width: 100%;
    }
    .nav-menu {
        display: none;
    }
    .banner h1 {
        font-size: 28px;
    }
    .banner p {
        font-size: 16px;
    }
    .module-wrap, .advantage-wrap {
        grid-template-columns: 1fr;
    }
    .contact-section {
        padding: 40px 20px;
    }
    .logo-img {
        height: 35px;
    }
    .logo-text {
        font-size: 16px;
    }
}