/* ==================== 全局样式 ==================== */
:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary-color: #0f172a;
    --accent-color: #06b6d4;
    --text-color: #334155;
    --text-light: #64748b;
    --bg-color: #ffffff;
    --bg-light: #f8fafc;
    --bg-dark: #0f172a;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

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

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

/* ==================== 按钮样式 ==================== */
.btn {
    display: inline-block;
    padding: 12px 32px;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.5);
}

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

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

.btn-block {
    display: block;
    width: 100%;
}

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

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-md);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 20px;
    font-weight: 700;
}

.logo-text {
    font-size: 20px;
    font-weight: 700;
    color: var(--secondary-color);
}

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

.nav-link {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-color);
    position: relative;
    padding: 5px 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: 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;
    gap: 5px;
    cursor: pointer;
    padding: 5px;
}

.nav-toggle span {
    width: 25px;
    height: 2px;
    background: var(--secondary-color);
    transition: var(--transition);
}

/* ==================== 首页横幅 ==================== */
.hero {
    position: relative;
    height: 100vh;
    min-height: 700px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 50%, #2563eb 100%);
    z-index: 0;
}

.hero-bg::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    opacity: 0.5;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: white;
    padding: 0 20px;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    text-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
}

.hero-title .highlight {
    background: linear-gradient(135deg, #ffffff, #93c5fd);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 2rem;
    font-weight: 300;
    margin-bottom: 15px;
    opacity: 0.95;
    letter-spacing: 8px;
}

.hero-desc {
    font-size: 1.2rem;
    opacity: 0.85;
    margin-bottom: 40px;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    color: white;
    opacity: 0.7;
    animation: bounce 2s infinite;
}

.mouse {
    width: 26px;
    height: 40px;
    border: 2px solid white;
    border-radius: 13px;
    margin: 0 auto 10px;
    position: relative;
}

.mouse::before {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background: white;
    border-radius: 2px;
    animation: scroll 2s infinite;
}

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

@keyframes scroll {
    0% {
        opacity: 1;
        top: 8px;
    }
    100% {
        opacity: 0;
        top: 20px;
    }
}

/* ==================== 通用区块样式 ==================== */
.section {
    padding: 100px 0;
}

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

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 10px;
}

.section-subtitle {
    font-size: 1rem;
    color: var(--text-light);
    text-transform: uppercase;
    letter-spacing: 3px;
}

/* ==================== 关于我们 ==================== */
.about {
    background: var(--bg-light);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text h3 {
    font-size: 1.8rem;
    color: var(--secondary-color);
    margin-bottom: 20px;
}

.about-text p {
    color: var(--text-color);
    margin-bottom: 15px;
    line-height: 1.8;
}

.about-stats {
    display: flex;
    gap: 40px;
    margin-top: 40px;
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.stat-label {
    display: block;
    font-size: 0.9rem;
    color: var(--text-light);
    margin-top: 5px;
}

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

.image-placeholder {
    width: 100%;
    max-width: 400px;
    aspect-ratio: 4/3;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: var(--shadow-xl);
}

.image-placeholder i {
    font-size: 80px;
    margin-bottom: 20px;
    opacity: 0.9;
}

.image-placeholder span {
    font-size: 1.2rem;
    font-weight: 500;
    opacity: 0.9;
}

/* ==================== 服务项目 ==================== */
.services {
    background: white;
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.service-card {
    background: white;
    border-radius: 16px;
    padding: 40px 30px;
    text-align: center;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.service-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
    border-color: transparent;
}

.service-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 25px;
    background: linear-gradient(135deg, var(--primary-light), var(--primary-color));
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.service-card:hover .service-icon {
    transform: scale(1.1) rotate(5deg);
}

.service-icon i {
    font-size: 32px;
    color: white;
}

.service-card h3 {
    font-size: 1.3rem;
    color: var(--secondary-color);
    margin-bottom: 15px;
}

.service-card p {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* ==================== 核心优势 ==================== */
.advantages {
    background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 100%);
    color: white;
}

.advantages .section-title {
    color: white;
}

.advantages .section-subtitle {
    color: rgba(255, 255, 255, 0.7);
}

.advantages-content {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
}

.advantage-item {
    display: flex;
    gap: 25px;
    padding: 30px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: var(--transition);
}

.advantage-item:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateX(10px);
}

.advantage-icon {
    flex-shrink: 0;
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.advantage-icon i {
    font-size: 24px;
    color: white;
}

.advantage-text h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
}

.advantage-text p {
    opacity: 0.8;
    font-size: 0.95rem;
    line-height: 1.7;
}

/* ==================== 联系我们 ==================== */
.contact {
    background: var(--bg-light);
}

.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;
    padding: 25px;
    background: white;
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.contact-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateX(5px);
}

.contact-icon {
    flex-shrink: 0;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-light), var(--primary-color));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.contact-icon i {
    font-size: 20px;
    color: white;
}

.contact-text h4 {
    font-size: 1rem;
    color: var(--secondary-color);
    margin-bottom: 5px;
}

.contact-text p {
    color: var(--text-light);
    font-size: 0.95rem;
}

.contact-form {
    background: white;
    padding: 40px;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
}

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

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 15px 20px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 15px;
    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(37, 99, 235, 0.1);
}

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

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

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand .logo {
    margin-bottom: 15px;
}

.footer-brand .logo-text {
    color: white;
}

.footer-brand p {
    opacity: 0.7;
    font-size: 0.95rem;
}

.footer-links h4,
.footer-contact h4 {
    font-size: 1.1rem;
    margin-bottom: 20px;
    color: white;
}

.footer-links ul li {
    margin-bottom: 12px;
}

.footer-links a {
    opacity: 0.7;
    font-size: 0.95rem;
}

.footer-links a:hover {
    opacity: 1;
    color: var(--primary-light);
}

.footer-contact p {
    opacity: 0.7;
    font-size: 0.95rem;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer-contact i {
    color: var(--primary-light);
}

.footer-bottom {
    padding: 25px 0;
    text-align: center;
}

.footer-bottom p {
    opacity: 0.6;
    font-size: 0.9rem;
    margin-bottom: 5px;
}

.footer-bottom a {
    opacity: 0.6;
    font-size: 0.9rem;
}

.footer-bottom a:hover {
    opacity: 1;
    color: var(--primary-light);
}

/* ==================== 回到顶部按钮 ==================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 20px;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    box-shadow: var(--shadow-lg);
    z-index: 999;
}

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

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

/* ==================== 响应式设计 ==================== */
@media (max-width: 992px) {
    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.5rem;
        letter-spacing: 4px;
    }

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

    .about-image {
        order: -1;
    }

    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

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

    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .navbar .container {
        height: 60px;
    }

    .nav-menu {
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 20px;
        gap: 0;
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-menu li {
        padding: 15px 0;
        border-bottom: 1px solid var(--border-color);
    }

    .nav-toggle {
        display: flex;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
        letter-spacing: 3px;
    }

    .hero-desc {
        font-size: 1rem;
    }

    .section {
        padding: 70px 0;
    }

    .section-title {
        font-size: 2rem;
    }

    .about-stats {
        flex-wrap: wrap;
        justify-content: center;
    }

    .services-grid {
        grid-template-columns: 1fr;
    }

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

    .footer-brand .logo {
        justify-content: center;
    }

    .footer-contact p {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.6rem;
    }

    .hero-buttons {
        flex-direction: column;
        width: 100%;
        max-width: 280px;
        margin: 0 auto;
    }

    .btn {
        padding: 12px 24px;
        width: 100%;
    }

    .service-card {
        padding: 30px 20px;
    }

    .contact-form {
        padding: 25px;
    }
}