/* ===== 基础重置与变量 ===== */
:root {
    --primary: #1a56db;
    --primary-dark: #1244b0;
    --primary-light: #e8effd;
    --accent: #06b6d4;
    --dark: #0f172a;
    --dark-2: #1e293b;
    --gray: #64748b;
    --gray-light: #94a3b8;
    --light: #f8fafc;
    --white: #ffffff;
    --gradient: linear-gradient(135deg, #1a56db 0%, #06b6d4 100%);
    --shadow: 0 4px 24px rgba(15, 23, 42, 0.08);
    --shadow-lg: 0 12px 40px rgba(15, 23, 42, 0.12);
    --radius: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html { scroll-behavior: smooth; scroll-padding-top: 80px; }

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--dark);
    background: var(--white);
    line-height: 1.7;
    overflow-x: hidden;
}

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ===== 导航栏 ===== */
.navbar {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    padding: 16px 0;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid transparent;
    transition: var(--transition);
}
.navbar.scrolled {
    padding: 10px 0;
    background: rgba(255, 255, 255, 0.95);
    border-bottom-color: rgba(0, 0, 0, 0.06);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.04);
}
.nav-container { display: flex; align-items: center; justify-content: space-between; }

.logo { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.logo-icon {
    font-size: 28px;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.logo-text { font-size: 20px; font-weight: 700; color: var(--dark); }

.nav-links {
    display: flex; list-style: none; gap: 8px; align-items: center;
}
.nav-links a {
    text-decoration: none; color: var(--gray);
    padding: 8px 18px; border-radius: 8px; font-size: 15px; font-weight: 500;
    transition: var(--transition);
}
.nav-links a:hover, .nav-links a.active { color: var(--primary); background: var(--primary-light); }

.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 6px; }
.nav-toggle span {
    display: block; width: 24px; height: 2px; background: var(--dark);
    margin: 5px 0; transition: var(--transition); border-radius: 2px;
}

/* ===== Hero横幅 ===== */
.hero {
    position: relative; min-height: 100vh;
    display: flex; align-items: center; justify-content: center;
    overflow: hidden; padding-top: 80px;
}
.hero-bg {
    position: absolute; inset: 0;
    background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 40%, #1a56db 100%);
}
.hero-bg::after {
    content: ''; position: absolute; inset: 0;
    background: radial-gradient(circle at 70% 30%, rgba(6, 182, 212, 0.15) 0%, transparent 50%),
                radial-gradient(circle at 30% 70%, rgba(26, 86, 219, 0.1) 0%, transparent 50%);
}
.hero-particles {
    position: absolute; inset: 0; overflow: hidden;
}
.hero-content { position: relative; z-index: 2; text-align: center; padding: 40px 0; }
.hero-title { margin-bottom: 24px; }
.title-line {
    display: block; font-size: clamp(36px, 6vw, 72px);
    font-weight: 900; color: var(--white); line-height: 1.2;
    letter-spacing: -1px;
}
.title-line.accent {
    background: linear-gradient(90deg, #38bdf8, #06b6d4, #34d399);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    background-clip: text;
}
.hero-subtitle {
    font-size: clamp(16px, 2vw, 20px); color: rgba(255, 255, 255, 0.7);
    max-width: 600px; margin: 0 auto 40px; font-weight: 300;
}
.hero-buttons { display: flex; gap: 16px; justify-content: center; margin-bottom: 60px; }

.btn {
    display: inline-flex; align-items: center; justify-content: center;
    padding: 14px 32px; border-radius: 12px; font-size: 16px; font-weight: 600;
    text-decoration: none; cursor: pointer; border: none; transition: var(--transition);
}
.btn-primary {
    background: var(--gradient); color: var(--white);
    box-shadow: 0 4px 16px rgba(26, 86, 219, 0.4);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(26, 86, 219, 0.5); }
.btn-outline {
    background: transparent; color: var(--white);
    border: 2px solid rgba(255, 255, 255, 0.3);
}
.btn-outline:hover { border-color: var(--white); background: rgba(255, 255, 255, 0.1); }
.btn-full { width: 100%; }

.hero-stats { display: flex; gap: 48px; justify-content: center; }
.stat-item { text-align: center; }
.stat-number {
    font-size: 42px; font-weight: 900; color: var(--white); line-height: 1;
}
.stat-suffix { font-size: 28px; font-weight: 700; color: var(--accent); }
.stat-label { display: block; font-size: 14px; color: rgba(255, 255, 255, 0.5); margin-top: 8px; }

.scroll-indicator {
    position: absolute; bottom: 32px; left: 50%; transform: translateX(-50%);
    text-align: center; color: rgba(255, 255, 255, 0.4); font-size: 12px;
}
.scroll-arrow {
    width: 20px; height: 20px; margin: 8px auto 0;
    border-right: 2px solid rgba(255, 255, 255, 0.4);
    border-bottom: 2px solid rgba(255, 255, 255, 0.4);
    transform: rotate(45deg); animation: scrollBounce 2s infinite;
}
@keyframes scrollBounce {
    0%, 100% { transform: rotate(45deg) translate(0, 0); opacity: 0.4; }
    50% { transform: rotate(45deg) translate(5px, 5px); opacity: 1; }
}

/* ===== 通用板块样式 ===== */
.section-header { text-align: center; margin-bottom: 60px; }
.section-tag {
    display: inline-block; font-size: 13px; font-weight: 600;
    color: var(--primary); letter-spacing: 3px; margin-bottom: 12px;
}
.section-title { font-size: clamp(28px, 4vw, 42px); font-weight: 800; color: var(--dark); }
.section-line {
    width: 60px; height: 4px; background: var(--gradient);
    margin: 16px auto 0; border-radius: 2px;
}

/* ===== 关于我们 ===== */
.about { padding: 100px 0; background: var(--white); }
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: start; }
.about-text h3 { font-size: 24px; margin-bottom: 20px; color: var(--dark); }
.about-text p { color: var(--gray); margin-bottom: 16px; font-size: 15px; }
.about-features { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 24px; }
.feature-tag {
    display: flex; align-items: center; gap: 8px;
    padding: 8px 16px; background: var(--primary-light);
    border-radius: 8px; font-size: 14px; font-weight: 500; color: var(--primary);
}
.about-visual { display: flex; flex-direction: column; gap: 20px; }
.visual-card {
    padding: 28px; border-radius: var(--radius);
    background: var(--light); border: 1px solid rgba(0, 0, 0, 0.04);
    transition: var(--transition);
}
.visual-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.card-icon { font-size: 32px; margin-bottom: 12px; }
.visual-card h4 { font-size: 18px; margin-bottom: 8px; color: var(--dark); }
.visual-card p { font-size: 14px; color: var(--gray); }

/* ===== 服务范围 ===== */
.services { padding: 100px 0; background: var(--light); }
.services-grid {
    display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px;
}
.service-card {
    padding: 36px 28px; border-radius: var(--radius);
    background: var(--white); border: 1px solid rgba(0, 0, 0, 0.04);
    text-align: center; transition: var(--transition); cursor: default;
}
.service-card:hover {
    transform: translateY(-8px); box-shadow: var(--shadow-lg);
    border-color: rgba(26, 86, 219, 0.1);
}
.service-icon { font-size: 40px; margin-bottom: 20px; }
.service-card h3 { font-size: 17px; font-weight: 700; margin-bottom: 12px; color: var(--dark); }
.service-card p { font-size: 14px; color: var(--gray); line-height: 1.6; }

/* ===== 核心优势 ===== */
.advantages { padding: 100px 0; background: var(--dark); }
.advantages .section-tag { color: var(--accent); }
.advantages .section-title { color: var(--white); }
.advantages-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 32px; }
.advantage-item {
    padding: 36px 28px; border-radius: var(--radius);
    background: var(--dark-2); border: 1px solid rgba(255, 255, 255, 0.06);
    transition: var(--transition);
}
.advantage-item:hover {
    transform: translateY(-4px); border-color: rgba(6, 182, 212, 0.3);
    box-shadow: 0 8px 32px rgba(6, 182, 212, 0.1);
}
.adv-number {
    font-size: 48px; font-weight: 900;
    background: var(--gradient); -webkit-background-clip: text;
    -webkit-text-fill-color: transparent; background-clip: text;
    margin-bottom: 16px; line-height: 1;
}
.advantage-item h3 { font-size: 18px; color: var(--white); margin-bottom: 12px; }
.advantage-item p { font-size: 14px; color: var(--gray-light); line-height: 1.7; }

/* ===== 联系我们 ===== */
.contact { padding: 100px 0; background: var(--white); }
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; }
.contact-info h3 { font-size: 24px; margin-bottom: 16px; }
.contact-info > p { color: var(--gray); margin-bottom: 32px; }
.contact-items { display: flex; flex-direction: column; gap: 24px; }
.contact-item { display: flex; gap: 16px; align-items: flex-start; }
.contact-icon { font-size: 24px; flex-shrink: 0; margin-top: 2px; }
.contact-item strong { display: block; font-size: 15px; color: var(--dark); margin-bottom: 2px; }
.contact-item p { font-size: 14px; color: var(--gray); margin: 0; }

.contact-form { display: flex; flex-direction: column; gap: 16px; }
.form-group input, .form-group textarea {
    width: 100%; padding: 14px 18px; border: 2px solid #e2e8f0;
    border-radius: 12px; font-size: 15px; font-family: inherit;
    transition: var(--transition); background: var(--light);
    outline: none;
}
.form-group input:focus, .form-group textarea:focus {
    border-color: var(--primary); background: var(--white);
    box-shadow: 0 0 0 4px var(--primary-light);
}
.form-group textarea { resize: vertical; min-height: 100px; }

/* ===== 页脚 ===== */
.footer { padding: 60px 0 0; background: var(--dark); color: rgba(255, 255, 255, 0.6); }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 48px; margin-bottom: 48px; }
.footer-brand .logo { margin-bottom: 16px; }
.footer-brand .logo-text { color: var(--white); }
.footer-brand p { font-size: 14px; line-height: 1.8; }
.footer-links h4 { color: var(--white); font-size: 16px; margin-bottom: 20px; }
.footer-links a {
    display: block; color: rgba(255, 255, 255, 0.5); text-decoration: none;
    font-size: 14px; padding: 6px 0; transition: var(--transition);
}
.footer-links a:hover { color: var(--white); transform: translateX(4px); }
.footer-bottom {
    padding: 24px 0; border-top: 1px solid rgba(255, 255, 255, 0.08);
    text-align: center; font-size: 13px;
}

/* ===== 动画 ===== */
.animate-in { opacity: 0; transform: translateY(30px); animation: fadeInUp 0.8s forwards; }
.animate-in:nth-child(2) { animation-delay: 0.15s; }
.animate-in:nth-child(3) { animation-delay: 0.3s; }
.animate-in:nth-child(4) { animation-delay: 0.45s; }

@keyframes fadeInUp {
    to { opacity: 1; transform: translateY(0); }
}

.fade-up { opacity: 0; transform: translateY(40px); transition: all 0.7s cubic-bezier(0.4, 0, 0.2, 1); }
.fade-up.visible { opacity: 1; transform: translateY(0); }

/* ===== 响应式布局 ===== */
@media (max-width: 1024px) {
    .services-grid { grid-template-columns: repeat(2, 1fr); }
    .advantages-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .nav-toggle { display: block; }
    .nav-links {
        display: none; position: absolute; top: 100%; left: 0; right: 0;
        flex-direction: column; background: var(--white);
        padding: 16px 24px; gap: 4px;
        box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
    }
    .nav-links.active { display: flex; }
    .nav-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
    .nav-toggle.active span:nth-child(2) { opacity: 0; }
    .nav-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

    .hero-stats { gap: 24px; }
    .stat-number { font-size: 32px; }

    .about-grid { grid-template-columns: 1fr; }
    .services-grid { grid-template-columns: 1fr; }
    .advantages-grid { grid-template-columns: 1fr; }
    .contact-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; gap: 32px; }

    .hero-buttons { flex-direction: column; align-items: center; }
}

/* ===== 粒子样式 ===== */
.particle {
    position: absolute; border-radius: 50%;
    background: rgba(255, 255, 255, 0.08);
    animation: particleFloat linear infinite;
}
@keyframes particleFloat {
    0% { transform: translateY(100vh) scale(0); opacity: 0; }
    10% { opacity: 1; }
    90% { opacity: 1; }
    100% { transform: translateY(-10vh) scale(1); opacity: 0; }
}