/* ===== 基础样式与变量 ===== */
:root {
    --primary-color: #0066cc;
    --primary-dark: #004d99;
    --secondary-color: #2ecc71;
    --dark-color: #1a1a1a;
    --light-color: #f8f9fa;
    --gray-color: #6c757d;
    --light-gray: #e9ecef;
    --white: #ffffff;
    --shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
    --transition: all 0.3s ease;
    --border-radius: 10px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', 'Segoe UI', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: var(--white);
    overflow-x: hidden;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.section {
    padding: 80px 0;
}

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

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--dark-color);
    margin-bottom: 1rem;
}

.section-subtitle {
    text-align: center;
    color: var(--gray-color);
    font-size: 1.1rem;
    margin-bottom: 3rem;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.btn {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    padding: 14px 32px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.05rem;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 4px 12px rgba(0, 102, 204, 0.2);
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 18px rgba(0, 102, 204, 0.3);
    color: white;
}

/* ===== 导航栏样式 ===== */
.navbar {
    background-color: var(--white);
    box-shadow: 0 2px 15px rgba(0, 0, 0, 0.08);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 18px 20px;
    height: 75px;
}

.logo {
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--dark-color);
    text-decoration: none;
    letter-spacing: 0.5px;
}

.logo-text {
    background: linear-gradient(90deg, var(--dark-color), var(--primary-color));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 40px;
}

.nav-links a {
    text-decoration: none;
    color: #555;
    font-weight: 600;
    font-size: 1.05rem;
    padding: 8px 2px;
    position: relative;
    transition: var(--transition);
}

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

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background-color: var(--primary-color);
    border-radius: 2px;
}

/* 语言切换按钮样式 */
.lang-btn {
    background: var(--light-gray);
    border: none;
    border-radius: 20px;
    padding: 8px 16px;
    font-weight: 600;
    color: var(--dark-color);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 5px;
    transition: var(--transition);
}

.lang-btn:hover {
    background: #dde4ea;
}

.lang-code {
    font-size: 0.95rem;
}

.lang-sep {
    color: var(--gray-color);
}

/* 当前激活的语言样式 */
.lang-code.active {
    color: var(--primary-color);
}

/* ===== 主页横幅样式 ===== */
.hero {
    background: linear-gradient(rgba(0, 40, 80, 0.85), rgba(0, 60, 120, 0.9)), url('https://images.unsplash.com/photo-1558494949-ef010cbdcc31?ixlib=rb-4.0.3&auto=format&fit=crop&w=1350&q=80');
    background-size: cover;
    background-position: center;
    color: white;
    text-align: center;
    padding: 180px 20px 100px;
    margin-top: 75px;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    letter-spacing: -0.5px;
}

.tagline {
    font-size: 1.8rem;
    font-weight: 300;
    margin-bottom: 1.5rem;
    opacity: 0.95;
}

.hero-desc {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto 2rem;
    opacity: 0.9;
    line-height: 1.7;
}

.subtitle {
    font-size: 1.6rem;
    font-weight: 600;
    margin-bottom: 3rem;
    opacity: 0.95;
}

/* ===== 优势区域样式 ===== */
.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.advantage-card {
    background: var(--white);
    padding: 40px 30px;
    border-radius: var(--border-radius);
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border-top: 4px solid var(--primary-color);
}

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

.advantage-card i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 25px;
}

.advantage-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--dark-color);
}

/* ===== 关于我们样式 ===== */
.about-text h3 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--dark-color);
}

.mission-vision {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
    margin: 40px 0;
}

.mv-item h4 {
    color: var(--primary-color);
    margin-bottom: 15px;
    font-size: 1.4rem;
}

.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.stat {
    text-align: center;
    padding: 25px 15px;
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

.number {
    display: block;
    font-size: 2.8rem;
    font-weight: 800;
    color: var(--primary-color);
    line-height: 1;
    margin-bottom: 10px;
}

.label {
    font-size: 1rem;
    color: var(--gray-color);
    font-weight: 500;
}

/* ===== 产品区域样式 ===== */
.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.product-card {
    background: var(--white);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    padding-bottom: 30px;
}

.product-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.12);
}

.product-img-placeholder {
    height: 180px;
    background: linear-gradient(135deg, var(--primary-color), #0099ff);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 25px;
}

.product-card h3 {
    text-align: center;
    color: var(--dark-color);
    margin-bottom: 15px;
    padding: 0 25px;
}

.product-card > p {
    text-align: center;
    color: var(--gray-color);
    padding: 0 25px;
    margin-bottom: 25px;
    line-height: 1.7;
}

.product-tags {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
    list-style: none;
    padding: 0 25px;
}

.product-tags li {
    background: var(--light-gray);
    color: var(--dark-color);
    padding: 6px 15px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
}

/* ===== 联系区域样式 ===== */
.contact-wrapper {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 50px;
    background: var(--white);
    padding: 50px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

.contact-info h3 {
    margin-bottom: 25px;
    color: var(--dark-color);
}

.contact-info p {
    margin-bottom: 18px;
    display: flex;
    align-items: center;
}

.contact-info i {
    color: var(--primary-color);
    margin-right: 12px;
    width: 20px;
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: 16px;
    margin-bottom: 22px;
    border: 1px solid var(--light-gray);
    border-radius: 8px;
    font-size: 1rem;
    font-family: 'Inter', sans-serif;
    transition: var(--transition);
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
}

.contact-form button {
    width: 100%;
}

/* ===== 页脚样式 ===== */
.footer {
    background-color: var(--dark-color);
    color: #aaa;
    text-align: center;
    padding: 35px 20px;
}

.footer p {
    margin-bottom: 10px;
}

.footer-note {
    font-size: 0.95rem;
    color: #888;
}

/* ===== 响应式设计 ===== */
@media (max-width: 992px) {
    .nav-links {
        gap: 25px;
    }
    .hero h1 {
        font-size: 3rem;
    }
}

@media (max-width: 768px) {
    .nav-container {
        padding: 15px;
        height: 70px;
    }
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        gap: 0;
        padding: 20px 0;
        box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
        border-top: 1px solid #eee;
        text-align: center;
    }
    .nav-links.active {
        display: flex;
    }
    .nav-links li {
        width: 100%;
    }
    .nav-links a {
        display: block;
        padding: 18px 20px;
        border-bottom: 1px solid #f5f5f5;
    }
    .hero {
        padding: 150px 20px 80px;
    }
    .hero h1 {
        font-size: 2.5rem;
    }
    .tagline {
        font-size: 1.5rem;
    }
    .section-title {
        font-size: 2.2rem;
    }
    .contact-wrapper {
        padding: 30px 25px;
    }
    .mission-vision {
        grid-template-columns: 1fr;
    }
}