/* ===== CSS 变量定义 ===== */
:root {
    /* 主色调 */
    --primary-color: #1a365d;
    --primary-light: #2a4a7f;
    --primary-lighter: #3a5a9f;
    
    /* 背景色 */
    --bg-white: #ffffff;
    --bg-light: #f8f9fa;
    --bg-gray: #f0f4f8;
    
    /* 文字色 */
    --text-dark: #333333;
    --text-gray: #666666;
    --text-light: #999999;
    
    /* 功能色 */
    --accent-blue: #007bff;
    --accent-green: #28a745;
    --accent-red: #dc3545;
    
    /* 字体 */
    --font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
    
    /* 间距 */
    --spacing-xs: 8px;
    --spacing-sm: 16px;
    --spacing-md: 24px;
    --spacing-lg: 48px;
    --spacing-xl: 64px;
    
    /* 过渡 */
    --transition: all 0.3s ease;
}

/* ===== 全局样式 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    color: var(--text-dark);
    line-height: 1.6;
    background-color: var(--bg-white);
}

/* ===== 导航栏 ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 16px 0;
    transition: var(--transition);
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.95);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    padding: 12px 0;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: var(--text-dark);
}

.navbar-brand .logo {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 600;
    font-size: 18px;
}

.navbar-brand .company-name {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-dark);
}

.navbar-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
}

.navbar-menu a {
    text-decoration: none;
    color: var(--text-dark);
    font-size: 15px;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

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

.navbar-menu a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

.navbar-menu a:hover::after {
    width: 100%;
}

/* 汉堡菜单 */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 5px;
}

.hamburger span {
    display: block;
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    transition: var(--transition);
}

/* ===== 首屏横幅 ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 50%, var(--primary-lighter) 100%);
    color: white;
    text-align: center;
    padding: var(--spacing-lg) var(--spacing-sm);
    position: relative;
}

.hero-content {
    max-width: 800px;
}

.hero h1 {
    font-size: 48px;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    animation: fadeInUp 1s ease;
}

.hero p {
    font-size: 20px;
    margin-bottom: var(--spacing-lg);
    opacity: 0.9;
    animation: fadeInUp 1s ease 0.2s;
    animation-fill-mode: both;
}

.hero .scroll-hint {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

.scroll-hint {
    color: white;
    font-size: 24px;
    opacity: 0.7;
}

/* ===== 通用板块样式 ===== */
.section {
    padding: var(--spacing-xl) var(--spacing-sm);
    max-width: 1200px;
    margin: 0 auto;
}

.section-title {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.section-title h2 {
    font-size: 32px;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: var(--spacing-xs);
}

.section-title p {
    font-size: 16px;
    color: var(--text-gray);
}

/* ===== 公司简介板块 ===== */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    align-items: start;
}

.about-timeline {
    position: relative;
    padding-left: var(--spacing-md);
}

.about-timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--primary-color);
}

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-md);
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -25px;
    top: 5px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--primary-color);
    border: 3px solid white;
    box-shadow: 0 0 0 2px var(--primary-color);
}

.timeline-item h4 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--primary-color);
}

.timeline-item p {
    font-size: 14px;
    color: var(--text-gray);
    line-height: 1.8;
}

.about-features {
    display: grid;
    gap: var(--spacing-sm);
}

.feature-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    background: var(--bg-light);
    border-radius: 8px;
    transition: var(--transition);
}

.feature-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 24px;
    flex-shrink: 0;
}

.feature-text h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 4px;
}

.feature-text p {
    font-size: 14px;
    color: var(--text-gray);
}

/* ===== 业务范围板块 ===== */
.services-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-md);
}

.service-card {
    background: var(--bg-white);
    border: 1px solid #e0e0e0;
    border-radius: 12px;
    padding: var(--spacing-md);
    text-align: center;
    transition: var(--transition);
    cursor: pointer;
}

.service-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
    border-color: var(--primary-color);
}

.service-card .icon {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--spacing-sm);
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 32px;
}

.service-card h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--text-dark);
}

.service-card p {
    font-size: 14px;
    color: var(--text-gray);
    line-height: 1.8;
}

/* ===== 技术能力板块 ===== */
.tech-section {
    margin-bottom: var(--spacing-lg);
}

.tech-section h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
    padding-left: var(--spacing-sm);
    border-left: 4px solid var(--primary-color);
}

.tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.tech-tag {
    padding: 8px 16px;
    background: var(--bg-light);
    border: 1px solid #e0e0e0;
    border-radius: 20px;
    font-size: 14px;
    color: var(--text-dark);
    transition: var(--transition);
}

.tech-tag:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

/* ===== 联系方式板块 ===== */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
}

.contact-form {
    background: var(--bg-light);
    padding: var(--spacing-md);
    border-radius: 12px;
}

.contact-form h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--text-dark);
}

.form-group {
    margin-bottom: var(--spacing-sm);
}

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

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    font-size: 14px;
    font-family: var(--font-family);
    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(26, 54, 93, 0.1);
}

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

.btn-submit {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.btn-submit:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(26, 54, 93, 0.3);
}

.contact-info {
    padding: var(--spacing-md);
}

.contact-info h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--text-dark);
}

.info-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.info-icon {
    width: 40px;
    height: 40px;
    background: var(--bg-gray);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    font-size: 20px;
    flex-shrink: 0;
}

.info-text h4 {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--text-gray);
}

.info-text p {
    font-size: 16px;
    color: var(--text-dark);
}

.map-placeholder {
    width: 100%;
    height: 200px;
    background: var(--bg-gray);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    font-size: 14px;
    margin-top: var(--spacing-md);
}

/* ===== 页脚 ===== */
.footer {
    background: var(--primary-color);
    color: white;
    padding: var(--spacing-lg) var(--spacing-sm);
    text-align: center;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

.footer p {
    margin-bottom: var(--spacing-xs);
    font-size: 14px;
    opacity: 0.9;
}

.footer a {
    color: white;
    text-decoration: none;
    transition: var(--transition);
}

.footer a:hover {
    opacity: 0.7;
}

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

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

/* ===== 响应式设计 ===== */
@media (max-width: 992px) {
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }
    
    .navbar-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: var(--spacing-sm);
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    }
    
    .navbar-menu.active {
        display: flex;
    }
    
    .hero h1 {
        font-size: 32px;
    }
    
    .hero p {
        font-size: 16px;
    }
    
    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .services-grid {
        grid-template-columns: 1fr;
    }
    
    .section {
        padding: var(--spacing-lg) var(--spacing-sm);
    }
    
    .section-title h2 {
        font-size: 24px;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 24px;
    }
    
    .hero p {
        font-size: 14px;
    }
    
    .feature-item {
        flex-direction: column;
    }
}