/* --- 全局变量与重置 --- */
:root {
    --primary-blue: #003366; /* 深海蓝 - 稳重 */
    --accent-blue: #007BFF;  /* 科技蓝 - 活力 */
    --light-blue: #E6F2FF;   /* 淡蓝背景 */
    --text-dark: #333333;
    --text-gray: #666666;
    --white: #ffffff;
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Helvetica Neue', Helvetica, Arial, "Microsoft YaHei", sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    background-color: var(--white);
}

a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* --- 通用工具类 --- */
.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
}

.section { padding: 80px 0; }
.bg-light { background-color: var(--light-blue); }

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-header h3 {
    font-size: 2.5rem;
    color: var(--primary-blue);
    margin-bottom: 15px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.section-header .line {
    width: 60px;
    height: 4px;
    background: var(--accent-blue);
    margin: 0 auto 20px;
}

.section-header p {
    color: var(--text-gray);
    font-size: 1.1rem;
    max-width: 700px;
    margin: 0 auto;
}

/* --- 导航栏 --- */
.navbar {
    background-color: var(--white);
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    height: 80px;
    display: flex;
    align-items: center;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
}

.logo h1 {
    color: var(--primary-blue);
    font-size: 1.8rem;
    font-weight: 700;
}

.logo span {
    display: block;
    font-size: 0.8rem;
    color: var(--accent-blue);
    letter-spacing: 2px;
    font-weight: 400;
}

.nav-links ul { display: flex; gap: 30px; }
.nav-links a {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-dark);
    transition: var(--transition);
}

.nav-links a:hover { color: var(--accent-blue); }
.hamburger { display: none; font-size: 1.5rem; cursor: pointer; }

/* --- 首屏 Hero --- */
.hero {
    height: 100vh;
    background: url('banner.jpg');
    background-size: cover; /* 确保图片铺满 */
    background-position: center; /* 确保图片居中 */
    /*background: linear-gradient(135deg, var(--primary-blue), var(--accent-blue));*/
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
    color: var(--white);
    margin-top: 0; /* 修正 */
}

.hero-content { position: relative; z-index: 2; }

.hero h2 {
    font-size: 3.5rem;
    margin-bottom: 20px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.hero p {
    font-size: 1.5rem;
    margin-bottom: 40px;
    opacity: 0.9;
}

.btn-primary {
    background-color: var(--white);
    color: var(--primary-blue);
    padding: 15px 40px;
    border-radius: 30px;
    font-weight: bold;
    font-size: 1.1rem;
    transition: var(--transition);
    border: 2px solid var(--white);
}

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

/* --- 企业简介 --- */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
}

.about-text p { margin-bottom: 20px; color: var(--text-gray); font-size: 1.1rem; }
.feature-list li { margin-bottom: 15px; color: var(--primary-blue); font-weight: 500; }
.feature-list i { margin-right: 10px; color: var(--accent-blue); }

.about-image img {
    width: 100%;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0,51,102,0.15);
}

/* --- 产品服务 --- */
.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.product-card {
    background: var(--white);
    padding: 40px 30px;
    border-radius: 8px;
    text-align: center;
    transition: var(--transition);
    border: 1px solid rgba(0,0,0,0.05);
}

.product-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,123,255,0.15);
    border-color: var(--accent-blue);
}

.icon-box {
    font-size: 3rem;
    color: var(--accent-blue);
    margin-bottom: 20px;
}

.product-card h4 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--primary-blue);
}

.product-card p { color: var(--text-gray); }

/* --- 联系我们 --- */
.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 50px;
    background: var(--white);
    padding: 50px;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0,0,0,0.05);
}

.info-item {
    display: flex;
    align-items: flex-start;
    margin-bottom: 30px;
}

.info-item i {
    font-size: 1.5rem;
    color: var(--accent-blue);
    margin-right: 20px;
    margin-top: 5px;
}

.info-item h5 { font-size: 1.2rem; margin-bottom: 5px; color: var(--primary-blue); }
.info-item p { color: var(--text-gray); }

.contact-form input, .contact-form textarea {
    width: 100%;
    padding: 15px;
    margin-bottom: 20px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-family: inherit;
}

.btn-submit {
    background-color: var(--primary-blue);
    color: var(--white);
    border: none;
    padding: 15px 40px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    transition: var(--transition);
    width: 100%;
}

.btn-submit:hover { background-color: var(--accent-blue); }

/* --- 页脚 --- */
footer {
    background-color: var(--primary-blue);
    color: var(--white);
    text-align: center;
    padding: 30px 0;
}

/* --- 动画 --- */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.delay-1 { transition-delay: 0.2s; }
.delay-2 { transition-delay: 0.4s; }

/* --- 响应式适配 --- */
@media (max-width: 768px) {
    .nav-links { display: none; }
    .hamburger { display: block; color: var(--primary-blue); }
    
    .hero h2 { font-size: 2.5rem; }
    .hero p { font-size: 1.2rem; }
    
    .about-grid, .contact-wrapper { grid-template-columns: 1fr; }
    .about-image { order: -1; } /* 图片在移动端置顶 */
    
    .section { padding: 60px 0; }
    .contact-wrapper { padding: 30px; }
}