/* 基础样式 */
body {
    font-family: 'Noto Sans SC', sans-serif;
    margin: 0;
    padding: 0;
    line-height: 1.6;
    color: #333;
    background-color: #f9f9f9;
    overflow-x: hidden; /* 防止水平滚动 */
}

header {
    background-color: #004080;
    color: white;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.navbar {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 20px;
    flex-wrap: wrap;
}

.nav-brand {
    display: flex;
    align-items: center;
    margin: 0;
}

.logo {
    width: 40px;
    height: 40px;
    margin-right: 10px;
}

.nav-brand h1 {
    margin: 0;
    font-size: 1.5em;
}

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

.nav-menu li {
    margin: 0 15px;
}

.nav-menu a {
    color: white;
    text-decoration: none;
    padding: 10px 5px;
    transition: color 0.3s;
}

.nav-menu a:hover {
    color: #ccc;
}

.lang-toggle {
    margin: 0 10px;
}

.lang-toggle button {
    background: none;
    border: none;
    color: white;
    cursor: pointer;
    text-decoration: underline;
}

.contact-info p {
    margin: 0;
    font-size: 0.9em;
}

main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* 固定 1920px × 700px 轮播图 + 滑动动画（宽度 100% 避免溢出） */
#hero {
    position: relative;
    width: 100%; /* 全宽适配，无水平溢出 */
    height: 700px;
    margin: 0 auto;
    padding-top: 80px; /* 避开固定导航栏 */
    overflow: hidden;
}

.carousel-container {
    position: relative;
    width: 100%;
    height: 100%;
}

.carousel-slides {
    display: flex;
    width: 100%; /* 3 张图片，总宽度 300% */
    height: 100%;
    transition: transform 1s ease-in-out; /* 滑动动画 1s 平滑过渡 */
}

.carousel-slide {
    flex: 0 0 100%; /* 每张占 100% 宽度 */
    background-size: cover;
    background-position: center;
}

.carousel-prev,
.carousel-next {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(0, 0, 0, 0.5);
    color: white;
    border: none;
    padding: 10px;
    cursor: pointer;
    font-size: 18px;
    z-index: 10;
}

.carousel-prev {
    left: 20px;
}

.carousel-next {
    right: 20px;
}

.hero-overlay {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    color: white;
    background: rgba(0, 64, 128, 0.7);
    padding: 20px;
    border-radius: 8px;
    z-index: 5;
}

.hero-overlay h1 {
    margin: 0 0 10px 0;
    font-size: 2.5em;
}

.hero-overlay p {
    margin: 0;
    font-size: 1.2em;
}

section {
    margin-bottom: 40px;
    padding: 20px;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

h2 {
    color: #004080;
    border-bottom: 2px solid #004080;
    padding-bottom: 10px;
}

ul {
    list-style-type: disc;
    padding-left: 20px;
}

.btn {
    display: inline-block;
    background-color: #004080;
    color: white;
    padding: 10px 20px;
    text-decoration: none;
    border-radius: 4px;
    margin-top: 10px;
    border: none;
    cursor: pointer;
}

.service-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}

.service-item {
    padding: 15px;
    border: 1px solid #ddd;
    border-radius: 4px;
}

/* 静态联系样式 */
.contact-static {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.contact-item {
    text-align: center;
    padding: 15px;
    border: 1px solid #ddd;
    border-radius: 4px;
}

.contact-item h3 {
    color: #004080;
    margin-bottom: 10px;
}

footer {
    background-color: #004080;
    color: white;
    text-align: center;
    padding: 20px;
    margin-top: 40px;
}

footer ul {
    list-style: none;
    padding: 0;
}

footer li {
    display: inline;
    margin: 0 10px;
}

footer a {
    color: white;
    text-decoration: none;
}

/* 响应式 */
@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        align-items: flex-start;
    }

    .nav-menu {
        flex-direction: column;
        width: 100%;
    }

    .nav-menu li {
        margin: 0;
    }

    .lang-toggle,
    .contact-info {
        margin-top: 10px;
    }

    #hero {
        height: 400px; /* 移动端优化高度 */
        padding-top: 120px; /* 调整避开导航 */
    }

    .hero-overlay h1 {
        font-size: 2em;
    }

    .service-grid,
    .contact-static {
        grid-template-columns: 1fr;
    }
}