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

:root {
    --primary: #1e40af;
    --primary-dark: #1e3a8a;
    --primary-light: #3b82f6;
    --accent: #f59e0b;
    --text: #1f2937;
    --text-light: #6b7280;
    --bg: #ffffff;
    --bg-alt: #f9fafb;
    --border: #e5e7eb;
    --shadow: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 30px rgba(0,0,0,0.1);
    --radius: 8px;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', 'Segoe UI', sans-serif;
    color: var(--text);
    line-height: 1.6;
    background: var(--bg);
}

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

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

/* ============== 导航栏 ============== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: var(--shadow);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 20px;
}

.logo {
    display: flex;
    align-items: baseline;
    gap: 8px;
    font-size: 20px;
    color: var(--primary);
}

.logo-sub {
    font-size: 13px;
    color: var(--text-light);
    font-weight: 400;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-menu a {
    color: var(--text);
    font-weight: 500;
    transition: color 0.2s;
}

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

.nav-toggle {
    display: none;
    background: none;
    border: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
    padding: 8px;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text);
    transition: 0.3s;
}

/* 语言切换按钮 */
.lang-toggle {
    background: var(--primary);
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.2s;
    margin-left: 12px;
}

.lang-toggle:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.lang-text {
    display: inline-block;
    min-width: 32px;
}

/* ============== Hero ============== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #1e40af 0%, #3b82f6 50%, #60a5fa 100%);
    color: white;
    padding-top: 80px;
}

.hero-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: clamp(32px, 5vw, 56px);
    font-weight: 700;
    margin-bottom: 24px;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: clamp(16px, 2vw, 20px);
    margin-bottom: 40px;
    opacity: 0.95;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 14px 32px;
    border-radius: var(--radius);
    font-weight: 600;
    transition: all 0.3s;
    cursor: pointer;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.2);
}

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

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

/* ============== 通用 Section ============== */
.section {
    padding: 80px 0;
}

.section-alt {
    background: var(--bg-alt);
}

.section-title {
    text-align: center;
    font-size: clamp(28px, 4vw, 40px);
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text);
}

.section-subtitle {
    text-align: center;
    color: var(--text-light);
    margin-bottom: 60px;
    font-size: 18px;
}

/* ============== 关于我们 ============== */
.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 32px;
}

.about-card {
    background: white;
    padding: 40px 28px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
}

.about-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.card-icon {
    font-size: 48px;
    margin-bottom: 16px;
}

.about-card h3 {
    font-size: 22px;
    margin-bottom: 16px;
    color: var(--primary);
}

.about-card p {
    color: var(--text-light);
}

/* ============== 业务领域 ============== */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
}

.service-item {
    background: white;
    padding: 32px 24px;
    border-left: 4px solid var(--primary);
    border-radius: var(--radius);
    transition: all 0.3s;
}

.service-item:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow);
}

.service-item h3 {
    color: var(--primary);
    margin-bottom: 12px;
    font-size: 20px;
}

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

/* ============== 联系方式 ============== */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
    max-width: 900px;
    margin: 0 auto;
}

.contact-card {
    background: white;
    padding: 32px 24px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    text-align: center;
    transition: transform 0.3s;
}

.contact-card:hover {
    transform: translateY(-4px);
}

.contact-icon {
    font-size: 40px;
    margin-bottom: 12px;
}

.contact-card h3 {
    color: var(--primary);
    margin-bottom: 12px;
}

.contact-card a {
    color: var(--primary);
    border-bottom: 1px dashed var(--primary);
}

.contact-card a:hover {
    border-bottom-style: solid;
}

/* ============== 页脚 ============== */
.footer {
    background: #1f2937;
    color: #d1d5db;
    padding: 48px 0 24px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 32px;
    margin-bottom: 32px;
}

.footer-info strong {
    color: white;
    font-size: 18px;
    display: block;
    margin-bottom: 8px;
}

.footer-info p {
    font-size: 14px;
    opacity: 0.8;
}

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    transition: color 0.2s;
}

.footer-links a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: 24px;
    border-top: 1px solid #374151;
    font-size: 14px;
    opacity: 0.7;
}

/* ============== 移动端 ============== */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 20px;
        gap: 16px;
        box-shadow: var(--shadow);
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-toggle {
        display: flex;
    }

    .lang-toggle {
        padding: 6px 12px;
        font-size: 13px;
        margin-left: 8px;
    }

    .hero {
        min-height: 80vh;
    }

    .footer-content {
        flex-direction: column;
    }
}