:root {
    --primary: #1a56db;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary: #0ea5e9;
    --accent: #06b6d4;
    --dark: #0f172a;
    --dark-light: #1e293b;
    --gray: #64748b;
    --gray-light: #94a3b8;
    --light: #f1f5f9;
    --white: #ffffff;
    --gradient: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --radius: 12px;
    --transition: all 0.3s ease;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body { font-family: 'Noto Sans SC', sans-serif; color: var(--dark); line-height: 1.7; background: var(--white); overflow-x: hidden; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
a { text-decoration: none; color: inherit; transition: var(--transition); }
ul { list-style: none; }

.btn { display: inline-block; padding: 14px 32px; border-radius: 8px; font-weight: 500; cursor: pointer; transition: var(--transition); border: 2px solid transparent; }
.btn-primary { background: var(--gradient); color: var(--white); border: none; }
.btn-primary:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.btn-outline { background: transparent; color: var(--white); border: 2px solid var(--white); }
.btn-outline:hover { background: var(--white); color: var(--primary); }

.navbar { position: fixed; top: 0; left: 0; right: 0; z-index: 1000; background: rgba(15, 23, 42, 0.95); backdrop-filter: blur(10px); transition: var(--transition); }
.nav-wrapper { display: flex; justify-content: space-between; align-items: center; height: 72px; }
.logo { display: flex; align-items: center; gap: 10px; font-size: 1.35rem; font-weight: 700; color: var(--white); }
.logo-icon { font-size: 1.8rem; }
.nav-menu { display: flex; gap: 8px; }
.nav-link { padding: 8px 16px; border-radius: 6px; color: rgba(255, 255, 255, 0.85); }
.nav-link:hover, .nav-link.active { background: rgba(255, 255, 255, 0.1); color: var(--white); }
.nav-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 8px; }
.nav-toggle span { width: 24px; height: 2px; background: var(--white); }

.hero { min-height: 100vh; display: flex; flex-direction: column; justify-content: center; align-items: center; text-align: center; padding: 120px 24px 80px; position: relative; background: var(--dark); overflow: hidden; }
.hero::before { content: ''; position: absolute; inset: 0; background: radial-gradient(circle at 20% 50%, rgba(26, 86, 219, 0.3) 0%, transparent 50%), radial-gradient(circle at 80% 50%, rgba(14, 165, 233, 0.3) 0%, transparent 50%); animation: pulse 8s ease-in-out infinite alternate; }
@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.7; } }
.hero-content { position: relative; z-index: 2; max-width: 800px; }
.title-zh { display: block; font-size: clamp(2.5rem, 5vw, 4rem); font-weight: 700; color: var(--white); margin-bottom: 8px; }
.title-en { display: block; font-size: clamp(1rem, 2vw, 1.25rem); font-weight: 300; color: var(--gray-light); letter-spacing: 1px; }
.hero-subtitle { font-size: clamp(1.25rem, 2.5vw, 1.75rem); color: var(--accent); margin-bottom: 16px; font-weight: 500; }
.hero-description { font-size: 1.1rem; color: var(--gray-light); margin-bottom: 40px; max-width: 600px; margin: 0 auto 40px; }
.hero-cta { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.hero-scroll { position: absolute; bottom: 32px; left: 50%; transform: translateX(-50%); text-align: center; color: var(--gray-light); font-size: 0.875rem; animation: bounce 2s infinite; }
.scroll-arrow { width: 24px; height: 24px; border-right: 2px solid var(--gray-light); border-bottom: 2px solid var(--gray-light); transform: rotate(45deg); margin: 8px auto 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); } }

.section { padding: 100px 0; }
.section-header { text-align: center; margin-bottom: 60px; }
.section-label { display: inline-block; font-size: 0.875rem; font-weight: 600; color: var(--primary); letter-spacing: 2px; margin-bottom: 12px; }
.section-title { font-size: clamp(2rem, 4vw, 2.75rem); font-weight: 700; color: var(--dark); margin-bottom: 16px; }
.section-divider { width: 60px; height: 4px; background: var(--gradient); border-radius: 2px; margin: 0 auto 20px; }
.section-subtitle { font-size: 1.1rem; color: var(--gray); max-width: 700px; margin: 0 auto; }

.about { background: var(--light); }
.about-content { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 24px; margin-bottom: 48px; }
.about-card { background: var(--white); padding: 32px; border-radius: var(--radius); box-shadow: var(--shadow); transition: var(--transition); }
.about-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-xl); }
.about-icon { font-size: 2.5rem; margin-bottom: 16px; }
.about-card h3 { font-size: 1.25rem; margin-bottom: 12px; color: var(--dark); }
.about-card p { color: var(--gray); line-height: 1.8; }
.about-values { display: flex; justify-content: center; gap: 48px; flex-wrap: wrap; }
.value-item { text-align: center; }
.value-icon { font-size: 2rem; margin-bottom: 8px; }
.value-item h4 { font-size: 1.1rem; color: var(--dark); }

.services-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px; }
.service-card { background: var(--white); padding: 32px; border-radius: var(--radius); border: 1px solid var(--light); box-shadow: var(--shadow); transition: var(--transition); }
.service-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-xl); border-color: var(--primary-light); }
.service-icon { width: 64px; height: 64px; margin-bottom: 20px; color: var(--primary); }
.service-icon svg { width: 100%; height: 100%; }
.service-card h3 { font-size: 1.25rem; margin-bottom: 12px; color: var(--dark); }
.service-card > p { color: var(--gray); margin-bottom: 20px; line-height: 1.7; }
.service-features li { position: relative; padding-left: 24px; margin-bottom: 8px; color: var(--gray); font-size: 0.95rem; }
.service-features li::before { content: ''; position: absolute; left: 0; top: 8px; width: 8px; height: 8px; background: var(--accent); border-radius: 50%; }

.development { background: var(--dark); color: var(--white); }
.development .section-label { color: var(--accent); }
.development .section-title { color: var(--white); }
.timeline { max-width: 800px; margin: 0 auto; position: relative; }
.timeline::before { content: ''; position: absolute; left: 24px; top: 0; bottom: 0; width: 2px; background: linear-gradient(to bottom, var(--primary), var(--secondary), var(--accent)); }
.timeline-item { display: flex; gap: 32px; margin-bottom: 48px; position: relative; }
.timeline-marker { flex-shrink: 0; width: 50px; display: flex; align-items: flex-start; justify-content: center; padding-top: 8px; }
.marker-dot { width: 16px; height: 16px; background: var(--gradient); border-radius: 50%; border: 3px solid var(--dark); box-shadow: 0 0 0 3px var(--primary); }
.timeline-content { background: var(--dark-light); padding: 28px; border-radius: var(--radius); flex: 1; }
.timeline-period { display: inline-block; background: var(--gradient); padding: 6px 16px; border-radius: 20px; font-size: 0.875rem; font-weight: 500; margin-bottom: 16px; }
.timeline-content h3 { font-size: 1.35rem; margin-bottom: 16px; color: var(--white); }
.timeline-content li { position: relative; padding-left: 24px; margin-bottom: 10px; color: var(--gray-light); }
.timeline-content li::before { content: ''; position: absolute; left: 0; top: 10px; width: 8px; height: 8px; background: var(--secondary); border-radius: 50%; }

.contact-wrapper { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; }
.contact-item { display: flex; gap: 20px; margin-bottom: 32px; }
.contact-icon { font-size: 2rem; flex-shrink: 0; }
.contact-details h4 { font-size: 1.1rem; margin-bottom: 8px; color: var(--dark); }
.contact-details p { color: var(--gray); line-height: 1.7; }
.contact-form-wrapper { background: var(--light); padding: 32px; border-radius: var(--radius); }
.contact-form { display: flex; flex-direction: column; gap: 20px; }
.form-group label { display: block; margin-bottom: 8px; font-weight: 500; color: var(--dark); }
.form-group input, .form-group textarea { width: 100%; padding: 14px 16px; border: 2px solid var(--light); border-radius: 8px; font-size: 1rem; font-family: inherit; transition: var(--transition); background: var(--white); }
.form-group input:focus, .form-group textarea:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(26, 86, 219, 0.1); }

.footer { background: var(--dark); color: var(--gray-light); padding: 48px 0 32px; text-align: center; }
.footer-brand { display: inline-flex; align-items: center; gap: 10px; font-size: 1.35rem; font-weight: 700; color: var(--white); margin-bottom: 12px; }
.footer-tagline { color: var(--accent); margin-bottom: 24px; }
.footer-links { display: flex; justify-content: center; gap: 24px; margin-bottom: 24px; flex-wrap: wrap; }
.footer-links a { color: var(--gray-light); }
.footer-links a:hover { color: var(--white); }
.copyright { font-size: 0.875rem; border-top: 1px solid var(--dark-light); padding-top: 24px; }

@media (max-width: 992px) { .contact-wrapper { grid-template-columns: 1fr; } }
@media (max-width: 768px) {
    .nav-toggle { display: flex; }
    .nav-menu { position: fixed; top: 72px; left: 0; right: 0; background: var(--dark); flex-direction: column; padding: 24px; transform: translateY(-100%); opacity: 0; visibility: hidden; transition: var(--transition); }
    .nav-menu.active { transform: translateY(0); opacity: 1; visibility: visible; }
    .nav-link { padding: 12px 16px; display: block; }
    .hero-cta { flex-direction: column; align-items: center; }
    .btn { width: 100%; max-width: 280px; text-align: center; }
    .about-values { gap: 32px; }
    .section { padding: 72px 0; }
    .timeline::before { left: 16px; }
    .timeline-marker { width: 36px; }
    .timeline-item { gap: 20px; }
}