/* 全局重置与基础样式 */
:root {
    --primary-color: #0056b3; /* 科技深蓝 */
    --secondary-color: #003d80;
    --accent-color: #f39c12; /* 强调色 */
    --text-color: #333;
    --light-text: #666;
    --bg-light: #f8f9fa;
    --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;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--white);
    scroll-behavior: smooth;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

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

/* Header & Navigation */
.header {
    background-color: var(--white);
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 15px 0;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo img {
    height: 50px;
    width: auto;
}

.company-name {
    margin-left: 15px;
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-color);
    vertical-align: middle;
}

.nav ul {
    display: flex;
    gap: 30px;
}

.nav a {
    font-weight: 500;
    color: var(--text-color);
    transition: var(--transition);
}

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

/* Hero Carousel */
.hero-carousel {
    background: linear-gradient(180deg, #f5f7fb 0%, #ffffff 100%);
    padding: 20px 0 10px;
}

.carousel-wrapper {
    position: relative;
    overflow: hidden;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.carousel-track {
    position: relative;
    height: 420px;
}

.carousel-slide {
    position: absolute;
    inset: 0;
    opacity: 0;
    transition: opacity 0.6s ease;
}

.carousel-slide.active {
    opacity: 1;
    z-index: 1;
}

.carousel-slide img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.carousel-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(0,0,0,0.45);
    color: #fff;
    border: none;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: grid;
    place-items: center;
    cursor: pointer;
    transition: var(--transition);
    z-index: 2;
}

.carousel-btn:hover {
    background: rgba(0,0,0,0.65);
}

.carousel-btn.prev {
    left: 12px;
}

.carousel-btn.next {
    right: 12px;
}

.carousel-dots {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    bottom: 14px;
    display: flex;
    gap: 8px;
    z-index: 2;
}

.carousel-dots .dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: rgba(255,255,255,0.7);
    border: none;
    cursor: pointer;
    transition: var(--transition);
}

.carousel-dots .dot.active {
    width: 24px;
    border-radius: 999px;
    background: var(--primary-color);
}

/* Sections General */
.section {
    padding: 40px 0;
}

.products-section,
.applications-section {
    padding: 30px 0;
}

.section-title {
    text-align: center;
    font-size: 32px;
    color: var(--secondary-color);
    margin-bottom: 50px;
    position: relative;
    padding-bottom: 15px;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background-color: var(--primary-color);
}

.section-title-left {
    text-align: left;
    font-size: 16px;
    color: var(--text-color);
    margin-bottom: 15px;
    padding: 10px 0;
    border-bottom: 1px solid #ddd;
}

.bg-light {
    background-color: var(--bg-light);
}

/* Intro Section - 联系信息 + 关于我们 并排 */
.intro-section {
    padding: 40px 0;
}

.intro-grid {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 30px;
}

.contact-sidebar {
    background: #fff;
}

.contact-card {
    border: 1px solid #ddd;
}

.contact-img {
    width: 100%;
    height: 160px;
    object-fit: cover;
}

.contact-details {
    padding: 15px;
    font-size: 13px;
    line-height: 1.8;
}

.contact-details p {
    margin-bottom: 5px;
    color: var(--text-color);
}

.about-main {
    background: #fff;
}

.about-text {
    font-size: 14px;
    line-height: 1.8;
    color: var(--light-text);
}

.about-text p {
    margin-bottom: 15px;
}

/* Product Section */
.product-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
}

.product-card {
    background: var(--white);
    border: 1px solid #ddd;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    text-align: center;
    overflow: hidden;
}

.product-card:hover {
    box-shadow: 0 5px 15px rgba(0,0,0,0.15);
    border-color: var(--primary-color);
}

.card-img {
    height: 180px;
    overflow: hidden;
    background-color: #fff;
    position: relative;
}

.card-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.product-card:hover .card-img img {
    transform: scale(1.05);
}

.card-content {
    padding: 12px 10px;
    background: var(--white);
    border-top: 1px solid #eee;
}

.card-content h3 {
    color: var(--text-color);
    font-size: 14px;
    font-weight: 500;
    margin: 0;
}

.view-details {
    display: none;
}

/* Culture Section */
.culture-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.culture-item {
    text-align: center;
    padding: 40px 20px;
}

.culture-item .icon {
    font-size: 48px;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.culture-item h3 {
    margin-bottom: 15px;
    color: var(--secondary-color);
}

.culture-item p {
    color: var(--light-text);
}

/* Applications Section */
.app-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
}

.app-card {
    background: var(--white);
    overflow: hidden;
    transition: var(--transition);
    border: 1px solid #ddd;
}

.app-card:hover {
    box-shadow: 0 5px 15px rgba(0,0,0,0.15);
    border-color: var(--primary-color);
}

.app-img {
    height: 160px;
    overflow: hidden;
    background-color: #fff;
}

.app-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.app-card:hover .app-img img {
    transform: scale(1.05);
}

/* Contact Section */
.contact-content {
    max-width: 800px;
    margin: 0 auto;
    background: var(--white);
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.05);
}

.contact-info {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 15px;
}

.contact-item i {
    font-size: 24px;
    color: var(--primary-color);
    margin-top: 5px;
}

.contact-item h4 {
    margin-bottom: 5px;
    color: var(--secondary-color);
}

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

/* Message Section */
.message-section {
    padding: 40px 0;
    background-color: var(--bg-light);
}

.message-form-container {
    max-width: 800px;
    margin: 0 auto;
    background: var(--white);
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.message-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    margin-bottom: 8px;
    color: var(--text-color);
    font-weight: 500;
    font-size: 14px;
}

.form-group .required {
    color: #e74c3c;
}

.form-group input,
.form-group textarea {
    padding: 10px 12px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 14px;
    font-family: inherit;
    transition: var(--transition);
    background-color: var(--white);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(0, 86, 179, 0.1);
}

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

.submit-btn {
    padding: 12px 30px;
    background-color: var(--primary-color);
    color: var(--white);
    border: none;
    border-radius: 4px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    align-self: flex-start;
}

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

.submit-btn:active {
    transform: translateY(1px);
}

/* Footer */
.footer {
    background-color: var(--secondary-color);
    color: var(--white);
    text-align: center;
    padding: 30px 0 20px;
    margin-top: 60px;
}

.footer-content {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-contact,
.footer-address {
    font-size: 14px;
    line-height: 1.8;
    margin: 0;
    opacity: 0.95;
}

.footer-copyright {
    font-size: 14px;
    margin: 15px 0 0 0;
    opacity: 0.8;
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    padding-top: 15px;
}

/* Responsive */
@media (max-width: 992px) {
    .product-grid,
    .app-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .intro-grid {
        grid-template-columns: 250px 1fr;
    }
}

@media (max-width: 768px) {
    .carousel-track {
        height: 260px;
    }

    .carousel-btn {
        width: 38px;
        height: 38px;
    }

    .header .container {
        flex-direction: column;
        gap: 15px;
    }

    .nav ul {
        flex-wrap: wrap;
        justify-content: center;
        gap: 15px;
    }

    .contact-info {
        grid-template-columns: 1fr;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .product-grid,
    .app-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .intro-grid {
        grid-template-columns: 1fr;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .product-grid,
    .app-grid {
        grid-template-columns: 1fr;
    }
}