/* --- 全局样式 --- */
  :root {
    --primary-blue: #003399;       /* 深蓝 */
    --accent-blue: #4b6eff;        /* 亮蓝/按钮色 */
    --bg-light: #f9fbff;           /* 极淡的背景蓝 */
    --text-dark: #333333;          /* 正文黑 */
    --text-gray: #666666;          /* 辅助灰 */
    --white: #ffffff;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Serif SC', serif; /* 强制使用思源宋体 */
    background-color: var(--white);
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
}
html {
    scroll-behavior: smooth;
    /* 2. 设置滚动偏移量，防止固定导航栏遮挡标题 */
    /* 假设你的导航栏高度约为 60px-80px，这里设置为 80px 以确保安全 */
    scroll-padding-top: 80px; 
}

/* 确保 section 和 footer 有足够的高度以便演示滚动效果 */
section, footer {
    /* 如果原本没有定义最小高度，可以加上，防止内容太少无法滚动测试 */
    min-height: auto; 
    padding-top: 20px; /* 增加一点顶部内边距，视觉更舒适 */
    padding-bottom: 40px;
}

/* 可选：给锚点目标添加一个焦点样式，方便调试 */
:target {
    /* 如果需要高亮当前选中的板块，可以在这里加样式 */
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* --- 通用工具类 --- */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
    z-index: 2;
}

.section-title {
    text-align: center;
    margin-bottom: 40px;
}

.section-title h2 {
    font-size: 2rem;
    color: var(--primary-blue);
    margin-bottom: 10px;
}

.section-title p {
    font-size: 1.2rem;
    color: var(--text-gray);
}

/* 装饰性圆点背景 */
.dots-bg {
    position: absolute;
    width: 100px;
    height: 100px;
    background-image: radial-gradient(#4b6eff 20%, transparent 20%);
    background-size: 10px 10px;
    opacity: 0.3;
    z-index: 1;
}

/* --- 顶部导航 --- */
header {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    padding: 20px 0;
    z-index: 10;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-links {
    display: flex;
    gap: 40px;
}

.nav-links a {
    color: #fff;
    font-size: 1.2rem;
    transition: color 0.3s;
    font-weight: bold;
}

.nav-links a:hover {
    color: var(--white);
}

.search-btn {
    background: var(--accent-blue);
    color: white;
    border: none;
    padding: 8px 15px;
    border-radius: 20px;
    cursor: pointer;
    font-family: inherit;
}

/* --- Hero Section (首屏) --- */
.hero {
    height: 90vh;
    background: url('../image/banner.jpg');
    background-size: cover;
    background-position: center;
    display: flex;
    align-items: center;
    position: relative;
    clip-path: polygon(0 0, 100% 0, 100% 85%, 0 100%);
}

.hero-content {
    color: var(--white);
    max-width: 850px;
}

.hero h1 {
    font-size: 4rem;
    line-height: 1.2;
    margin-bottom: 30px;
    text-shadow: 0 4px 10px rgba(0,0,0,0.3);
}

.btn-enter:hover {
    transform: translateY(-3px);
    background-color: #3a5bd9;
}

.btn-enter span {
    margin-left: 10px;
}

/* 浮动的小图片装饰 */
.floating-imgs {
    position: absolute;
    right: 10%;
    bottom: 10%;
    display: flex;
    gap: 20px;
}

.float-card {
    width: 200px;
    height: 140px;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
    transform: rotate(-5deg);
}

.float-card:nth-child(2) {
    transform: rotate(5deg) translateY(20px);
}

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

/* --- About Us Section --- */
.about-section {
    padding: 100px 0;
    position: relative;
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-img-wrapper {
    position: relative;
}

.about-img {
    width: 100%;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    display: block;
}

/* 模拟图片上的白色装饰条 */
.img-deco-bar {
    position: absolute;
    top: -20px;
    left: 20px;
    width: 80%;
    height: 20px;
    background: var(--white);
    border-radius: 10px;
    z-index: 2;
}

.about-text h3 {
    font-size: 2.5rem;
    color: var(--primary-blue);
    margin-bottom: 20px;
}

.about-text p {
    font-size: 1.1rem;
    color: var(--text-gray);
    margin-bottom: 30px;
    text-align: justify;
}

.btn-outline {
    display: inline-block;
    border: 2px solid var(--primary-blue);
    color: var(--primary-blue);
    padding: 10px 25px;
    border-radius: 20px;
    font-weight: bold;
    transition: all 0.3s;
}

.btn-outline:hover {
    background: var(--primary-blue);
    color: var(--white);
}

/* --- Product Resources Section --- */
.products-section {
    padding: 80px 0;
    background-color: var(--bg-light);
    position: relative;
}

.cards-container {
    display: flex;
    justify-content: center;
    gap: 30px;
    flex-wrap: wrap;
}

.card {
    background: var(--white);
    border: 1px solid #e1e1e1;
    border-radius: 20px;
    padding: 40px 20px;
    width: 300px;
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
    position: relative;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 51, 153, 0.1);
}

/* 中间卡片高亮样式 */
.card.highlight {
    background: var(--primary-blue);
    color: var(--white);
    border: none;
}

.card-icon {
    font-size: 2.5rem;
    margin-bottom: 20px;
    color: var(--accent-blue);
}

.card.highlight .card-icon {
    color: var(--white);
}

.card h4 {
    font-size: 1.2rem;
    margin-bottom: 15px;
}

.card p {
    font-size: 0.9rem;
    color: var(--text-gray);
    line-height: 1.8;
}

.card.highlight p {
    color: rgba(255, 255, 255, 0.8);
}

/* --- Footer --- */
footer {
    background-color: var(--primary-blue);
    color: var(--white);
    padding: 60px 0 30px;
    margin-top: 50px;
    border-top-left-radius: 40px;
    border-top-right-radius: 40px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-col h5 {
    font-size: 1rem;
    margin-bottom: 15px;
    opacity: 0.8;
    letter-spacing: 1px;
}

.footer-col p {
    font-size: 1.1rem;
    margin-bottom: 10px;
}

.contact-search {
    text-align: center;
    margin-bottom: 40px;
}

.search-input-group {
    background: rgba(255,255,255,0.1);
    display: inline-flex;
    align-items: center;
    padding: 10px 20px;
    border-radius: 30px;
    backdrop-filter: blur(5px);
}

.search-input-group input {
    background: transparent;
    border: none;
    color: var(--white);
    outline: none;
    font-family: inherit;
    font-size: 1rem;
}

.search-input-group input::placeholder {
    color: rgba(255,255,255,0.6);
}

.copyright {
    text-align: center;
    border-top: 1px solid rgba(255,255,255,0.1);
    padding-top: 20px;
    font-size: 0.9rem;
    opacity: 0.6;
}

/* --- 响应式调整 --- */
@media (max-width: 768px) {
    .hero h1 { font-size: 2.5rem; }
    .about-grid { grid-template-columns: 1fr; }
    .nav-links { display: none; } /* 移动端简化隐藏菜单 */
    .floating-imgs { display: none; }
    .footer-content { flex-direction: column; text-align: center; }
}