/* ==================== 基础样式 ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #162174;
    --primary-dark: #091045;
    --secondary-color: #2c3e50;
    --text-color: #333333;
    --light-gray: #f8f9fa;
    --gray: #6c757d;
    --white: #ffffff;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 5px 20px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--white);
}

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

/* ==================== 导航栏 ==================== */
.navbar {
    background-color: var(--white);
    box-shadow: var(--shadow);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: var(--shadow-hover);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

.nav-brand .logo-img {
    height: 50px;
    width: auto;
    display: block;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 30px;
}

.nav-link {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: var(--transition);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--text-color);
    transition: var(--transition);
}

/* ==================== 按钮样式 ==================== */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
}

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

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.btn-secondary {
    background-color: transparent;
    color: var(--white);
    border: 2px solid var(--white);
}

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

.btn-full {
    width: 100%;
}

/* ==================== 首页横幅 ==================== */
.hero {
    height: 100vh;
    background: linear-gradient(135deg, rgba(22, 33, 116, 0.9), rgba(22, 33, 116, 0.9)) center/cover no-repeat;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: var(--white);
    padding-top: 80px;
}

.hero-content {
    max-width: 800px;
    animation: fadeInUp 1s ease;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
    font-size: 24px;
    margin-bottom: 15px;
    font-weight: 500;
}

.hero-description {
    font-size: 18px;
    margin-bottom: 30px;
    opacity: 0.95;
}

.hero-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

/* ==================== 通用区块样式 ==================== */
section {
    padding: 80px 0;
}

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

.section-title {
    font-size: 36px;
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 15px;
}

.section-subtitle {
    font-size: 18px;
    color: var(--gray);
}

/* ==================== 产品系列 ==================== */
.products {
    background-color: var(--light-gray);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.product-card {
    background-color: var(--white);
    padding: 40px 30px;
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    text-align: center;
}

.product-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
}

.product-icon {
    width: 80px;
    height: 80px;
    background-color: rgba(22, 33, 116, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 36px;
    color: var(--primary-color);
}

.product-title {
    font-size: 22px;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 15px;
}

.product-description {
    color: var(--gray);
    margin-bottom: 20px;
    line-height: 1.8;
}

.product-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.product-link:hover {
    color: var(--primary-dark);
    gap: 10px;
}

/* ==================== 关于我们 ==================== */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-description {
    color: var(--gray);
    margin-bottom: 20px;
    line-height: 1.8;
}

.about-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-top: 30px;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-color);
}

.feature-item i {
    color: var(--primary-color);
    font-size: 18px;
}

.about-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.image-placeholder {
    width: 100%;
    height: 400px;
    background: linear-gradient(135deg, rgba(22, 33, 116, 0.1), rgba(22, 33, 116, 0.1));
    border-radius: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    font-size: 80px;
    color: var(--primary-color);
}

.image-placeholder span {
    font-size: 24px;
    margin-top: 15px;
    font-weight: 500;
}

/* ==================== 品质保证 ==================== */
.quality {
    background-color: var(--light-gray);
}

.quality-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.quality-card {
    background-color: var(--white);
    padding: 40px 30px;
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.quality-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background-color: var(--primary-color);
}

.quality-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.quality-number {
    font-size: 48px;
    font-weight: 700;
    color: rgba(22, 33, 116, 0.2);
    margin-bottom: 20px;
}

.quality-title {
    font-size: 20px;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 15px;
}

.quality-description {
    color: var(--gray);
    line-height: 1.8;
}

/* ==================== 联系我们 ==================== */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.contact-item {
    display: flex;
    gap: 20px;
    align-items: flex-start;
}

.contact-icon {
    width: 50px;
    height: 50px;
    background-color: rgba(22, 33, 116, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    color: var(--primary-color);
    flex-shrink: 0;
}

.contact-text h4 {
    font-size: 18px;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 5px;
}

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

.contact-form {
    background-color: var(--light-gray);
    padding: 40px;
    border-radius: 10px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 16px;
    font-family: inherit;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(22, 33, 116, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* ==================== 页脚 ==================== */
.footer {
    background-color: var(--secondary-color);
    color: var(--white);
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section .footer-logo-img {
    height: 50px;
    width: auto;
    margin-bottom: 15px;
    display: block;
}

.footer-description {
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 20px;
}

.social-links {
    display: flex;
    gap: 15px;
}

.social-link {
    width: 40px;
    height: 40px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    transition: var(--transition);
}

.social-link:hover {
    background-color: var(--primary-color);
    transform: translateY(-3px);
}

.footer-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 20px;
    color: var(--white);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 10px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--white);
    padding-left: 5px;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
}

.footer-bottom .icp-number {
    margin-top: 10px;
    font-size: 14px;
}

.footer-bottom .icp-number a {
    color: rgba(255, 255, 255, 0.5);
    text-decoration: none;
    transition: var(--transition);
}

.footer-bottom .icp-number a:hover {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: underline;
}

/* ==================== 返回顶部按钮 ==================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background-color: var(--primary-color);
    color: var(--white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    font-size: 20px;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
    box-shadow: var(--shadow);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background-color: var(--primary-dark);
    transform: translateY(-5px);
}

/* ==================== 响应式设计 ==================== */
@media (max-width: 992px) {
    .hero-title {
        font-size: 40px;
    }

    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .about-image {
        order: -1;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background-color: var(--white);
        flex-direction: column;
        justify-content: center;
        gap: 20px;
        transition: var(--transition);
        box-shadow: var(--shadow);
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .hero-title {
        font-size: 32px;
    }

    .hero-subtitle {
        font-size: 20px;
    }

    .hero-description {
        font-size: 16px;
    }

    .section-title {
        font-size: 28px;
    }

    .section-subtitle {
        font-size: 16px;
    }

    .products-grid,
    .quality-grid {
        grid-template-columns: 1fr;
    }

    .about-features {
        grid-template-columns: 1fr;
    }

    .contact-form {
        padding: 30px 20px;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        max-width: 300px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 28px;
    }

    .hero-subtitle {
        font-size: 18px;
    }

    .section-title {
        font-size: 24px;
    }

    .product-card,
    .quality-card {
        padding: 30px 20px;
    }

    .footer-content {
        grid-template-columns: 1fr;
    }
}