* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft YaHei", sans-serif;
}

:root {
    --main-color: #2c3e50;
    --sub-color: #34495e;
    --light-color: #f5f6fa;
    --text-color: #333;
    --border-color: #ddd;
}

body {
    color: var(--text-color);
    background: #f9f9f9;
    line-height: 1.6;
}

.container {
    width: 92%;
    max-width: 1200px;
    margin: 0 auto;
}

/* ==================== 导航样式（最终稳定版，防广告+不变形） ==================== */
#top {
    background: var(--main-color);
    padding: 14px 0;
    width: 100%;
    /* 取消fixed/sticky 彻底规避广告拦截 */
    position: relative;
    z-index: 999;
}

.nav-wrap {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    position: relative;
}

.logo {
    color: #fff;
    font-size: 20px;
    font-weight: bold;
}

.menu {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
}

.menu li {
    margin-left: 24px;
}

.menu a {
    color: #fff;
    text-decoration: none;
    font-size: 15px;
    transition: 0.2s;
}

.menu a.active,
.menu a:hover {
    color: #dcdde1;
    border-bottom: 2px solid #dcdde1;
    padding-bottom: 3px;
}

/* 移动端菜单按钮 */
.mobile-btn {
    display: none;
    color: #fff;
    font-size: 24px;
    cursor: pointer;
}

/* 移动端适配 768px 以下 */
@media (max-width: 768px) {
    .menu {
        display: none;
        flex-direction: column;
        background: var(--sub-color);
        width: 100%;
        margin-top: 10px;
        padding: 10px 0;
    }
    .menu li {
        margin: 10px 0;
        text-align: center;
        margin-left: 0;
    }
    .mobile-btn {
        display: block;
    }
    .menu.show {
        display: flex;
    }
}

/* ==================== 页面通用样式（保留原有所有样式） ==================== */
.banner {
    height: 500px;
    background: url("https://picsum.photos/id/1000/1920/1080") center/cover no-repeat;
    display: flex;
    align-items: center;
    color: white;
    text-align: center;
    position: relative;
}

.banner::before {
    content: "";
    position: absolute;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.45);
}

.banner-content {
    position: relative;
    z-index: 2;
    width: 100%;
}

.banner h1 {
    font-size: 42px;
    margin-bottom: 15px;
}

.banner p {
    font-size: 18px;
    max-width: 700px;
    margin: 0 auto;
}

@media (max-width: 768px) {
    .banner {
        height: 320px;
    }
    .banner h1 {
        font-size: 28px;
    }
}

.section {
    padding: 60px 0;
    background: white;
    margin-bottom: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.section-title {
    text-align: center;
    font-size: 28px;
    color: var(--main-color);
    margin-bottom: 40px;
    position: relative;
}

.section-title::after {
    content: "";
    width: 60px;
    height: 3px;
    background: var(--sub-color);
    display: block;
    margin: 12px auto 0;
}

.home-intro {
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
    font-size: 16px;
    color: #555;
}

.card-box {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 25px;
    margin-top: 30px;
}

.card {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    transition: 0.3s;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.card-text {
    padding: 18px;
}

.card-text h3 {
    font-size: 18px;
    margin-bottom: 8px;
    color: var(--main-color);
}

.card-text p {
    font-size: 14px;
    color: #666;
}

footer {
    background: var(--main-color);
    color: white;
    text-align: center;
    padding: 30px 0;
    margin-top: 30px;
}

footer p {
    font-size: 14px;
    opacity: 0.9;
}

.page-banner {
    height: 260px;
    background: var(--sub-color);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.page-banner h2 {
    font-size: 32px;
}

.content-page {
    padding: 50px 0;
    line-height: 1.8;
    font-size: 16px;
}