/* === 全局样式 === */
:root {
    --primary: #4F46E5;
    --primary-dark: #4338CA;
    --primary-light: #EEF2FF;
    --accent: #3B82F6;
    --success: #10B981;
    --warning: #F59E0B;
    --dark: #1E293B;
    --gray: #64748B;
    --light: #F8FAFC;
    --white: #FFFFFF;
    --radius: 16px;
    --shadow: 0 1px 3px 0 rgba(0,0,0,0.06), 0 1px 2px -1px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.07), 0 2px 4px -2px rgba(0,0,0,0.05);
    --shadow-lg: 0 10px 25px -5px rgba(0,0,0,0.08), 0 8px 10px -6px rgba(0,0,0,0.05);
    --shadow-xl: 0 20px 40px -5px rgba(0,0,0,0.1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
    color: var(--dark);
    line-height: 1.6;
    background: var(--white);
    overflow-x: hidden;
}

/* === 导航栏 === */
.navbar {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    background: rgba(255,255,255,0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(229,231,235,0.5);
    transition: all 0.3s ease;
}
.navbar.scrolled { box-shadow: var(--shadow-lg); background: rgba(255,255,255,0.95); }
.nav-container {
    max-width: 1280px; margin: 0 auto; padding: 0 24px;
    display: flex; align-items: center; justify-content: space-between;
    height: 72px;
}
.logo {
    display: flex; align-items: center; gap: 10px;
    font-size: 1.35rem; font-weight: 800; color: var(--dark);
    text-decoration: none; letter-spacing: -0.5px;
}
.logo-icon {
    width: 40px; height: 40px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: 12px;
    display: flex; align-items: center; justify-content: center;
    color: white; font-size: 1.2rem; font-weight: bold;
}
.nav-links { display: flex; align-items: center; gap: 4px; list-style: none; }
.nav-links a {
    text-decoration: none; color: var(--gray); font-weight: 500;
    font-size: 0.925rem; padding: 8px 16px; border-radius: 10px;
    transition: all 0.2s;
}
.nav-links a:hover { color: var(--primary); background: var(--primary-light); }
.nav-cta {
    background: var(--primary) !important; color: white !important;
    padding: 10px 22px !important; border-radius: 12px !important;
    font-weight: 600 !important; transition: all 0.3s;
}
.nav-cta:hover { background: var(--primary-dark) !important; color: white !important; transform: translateY(-1px); box-shadow: 0 4px 12px rgba(79,70,229,0.3); }
.mobile-menu-btn { display: none; background: none; border: none; font-size: 1.5rem; cursor: pointer; color: var(--dark); }

/* === Hero === */
.hero {
    padding: 140px 24px 80px;
    background: linear-gradient(180deg, #EEF2FF 0%, #FFFFFF 100%);
}
.hero-container {
    max-width: 1280px; margin: 0 auto;
    display: grid; grid-template-columns: 1fr 1fr; gap: 60px;
    align-items: center;
}
.hero-content { }
.hero-badge {
    display: inline-flex; align-items: center; gap: 8px;
    background: var(--primary-light); color: var(--primary);
    font-size: 0.875rem; font-weight: 600;
    padding: 8px 16px; border-radius: 50px; margin-bottom: 24px;
}
.hero-badge i { font-size: 0.75rem; }
.hero-title {
    font-size: 3.2rem; font-weight: 900; line-height: 1.2;
    letter-spacing: -1px; margin-bottom: 20px;
    background: linear-gradient(135deg, #1E293B 0%, #4F46E5 100%);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    background-clip: text;
}
.hero-desc { font-size: 1.15rem; color: var(--gray); line-height: 1.7; margin-bottom: 36px; max-width: 520px; }
.hero-buttons { display: flex; gap: 16px; flex-wrap: wrap; }
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 14px 32px; border-radius: 14px; font-size: 1rem; font-weight: 600; text-decoration: none; transition: all 0.3s; border: none; cursor: pointer; }
.btn-primary { background: var(--primary); color: white; box-shadow: 0 4px 16px rgba(79,70,229,0.3); }
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(79,70,229,0.35); }
.btn-outline { background: white; color: var(--primary); border: 2px solid #E0E7FF; }
.btn-outline:hover { background: var(--primary-light); border-color: var(--primary); transform: translateY(-2px); box-shadow: var(--shadow-md); }
.check-list { display: flex; flex-wrap: wrap; gap: 16px; margin-top: 28px; }
.check-list span { display: flex; align-items: center; gap: 6px; font-size: 0.875rem; color: var(--gray); font-weight: 500; }
.check-list i { color: var(--success); }
.hero-image {
    display: flex; justify-content: center; align-items: center;
}
.hero-image img { max-width: 100%; border-radius: 20px; }

/* === 通用区块 === */
.section { padding: 80px 24px; }
.section-container { max-width: 1280px; margin: 0 auto; }
.section-header { text-align: center; margin-bottom: 56px; }
.section-tag {
    display: inline-block; background: var(--primary-light); color: var(--primary);
    font-size: 0.85rem; font-weight: 700; padding: 6px 16px;
    border-radius: 50px; margin-bottom: 16px; letter-spacing: 0.5px;
    text-transform: uppercase;
}
.section-title { font-size: 2.4rem; font-weight: 800; letter-spacing: -0.5px; margin-bottom: 14px; color: var(--dark); }
.section-desc { font-size: 1.1rem; color: var(--gray); max-width: 640px; margin: 0 auto; }

/* === Features === */
.features-grid {
    display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
}
.feature-card {
    background: white; border: 1px solid #F1F5F9;
    border-radius: var(--radius); padding: 32px 28px;
    transition: all 0.3s ease; position: relative; overflow: hidden;
}
.feature-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    transform: scaleX(0); transition: transform 0.3s;
}
.feature-card:hover::before { transform: scaleX(1); }
.feature-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-xl); border-color: transparent; }
.feature-icon {
    width: 56px; height: 56px; border-radius: 14px;
    background: linear-gradient(135deg, var(--primary-light), #E0E7FF);
    display: flex; align-items: center; justify-content: center;
    margin-bottom: 20px; font-size: 1.5rem; color: var(--primary);
    transition: all 0.3s;
}
.feature-card:hover .feature-icon {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white; transform: scale(1.05);
}
.feature-card h3 { font-size: 1.2rem; font-weight: 700; margin-bottom: 10px; color: var(--dark); }
.feature-card p { font-size: 0.95rem; color: var(--gray); line-height: 1.65; }

/* === Stats === */
.stats-section { background: var(--dark); padding: 60px 24px; }
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 30px; text-align: center; }
.stat-item { }
.stat-number { font-size: 2.8rem; font-weight: 900; color: white; margin-bottom: 6px; letter-spacing: -1px; }
.stat-label { font-size: 0.95rem; color: rgba(255,255,255,0.6); font-weight: 500; }

/* === Testimonials === */
.testimonials-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.testimonial-card {
    background: white; border: 1px solid #F1F5F9;
    border-radius: var(--radius); padding: 30px;
    transition: all 0.3s;
}
.testimonial-card:hover { box-shadow: var(--shadow-xl); transform: translateY(-4px); }
.testimonial-stars { color: #F59E0B; margin-bottom: 16px; font-size: 0.95rem; }
.testimonial-text { font-size: 0.95rem; color: var(--dark); line-height: 1.7; margin-bottom: 20px; font-style: italic; }
.testimonial-author { display: flex; align-items: center; gap: 12px; }
.testimonial-author img { width: 44px; height: 44px; border-radius: 50%; background: var(--primary-light); }
.testimonial-author h4 { font-size: 0.95rem; font-weight: 700; }
.testimonial-author span { font-size: 0.8rem; color: var(--gray); }

/* === FAQ === */
.faq-list { max-width: 800px; margin: 0 auto; display: flex; flex-direction: column; gap: 14px; }
.faq-item { border: 1px solid #E5E7EB; border-radius: 14px; overflow: hidden; transition: all 0.3s; }
.faq-item:hover { border-color: var(--primary); }
.faq-question {
    width: 100%; text-align: left; background: white; border: none;
    padding: 20px 24px; font-size: 1.05rem; font-weight: 600;
    color: var(--dark); cursor: pointer;
    display: flex; align-items: center; justify-content: space-between;
    gap: 16px;
}
.faq-question i { transition: transform 0.3s; color: var(--gray); font-size: 0.85rem; }
.faq-item.open .faq-question i { transform: rotate(180deg); color: var(--primary); }
.faq-answer {
    max-height: 0; overflow: hidden; transition: all 0.35s ease;
    font-size: 0.95rem; color: var(--gray); line-height: 1.7;
}
.faq-item.open .faq-answer { max-height: 300px; padding: 0 24px 20px; }

/* === CTA === */
.cta-section { background: linear-gradient(135deg, var(--primary), #7C3AED); padding: 80px 24px; }
.cta-content { text-align: center; color: white; }
.cta-content h2 { font-size: 2.4rem; font-weight: 900; margin-bottom: 16px; letter-spacing: -0.5px; }
.cta-content p { font-size: 1.1rem; opacity: 0.85; margin-bottom: 36px; max-width: 560px; margin-left: auto; margin-right: auto; }
.btn-white { background: white; color: var(--primary); padding: 16px 40px; font-size: 1.1rem; border-radius: 14px; display: inline-flex; align-items: center; gap: 8px; text-decoration: none; font-weight: 700; transition: all 0.3s; }
.btn-white:hover { transform: translateY(-2px); box-shadow: 0 12px 30px rgba(0,0,0,0.2); }

/* === Footer === */
.footer { background: #0F172A; color: rgba(255,255,255,0.6); padding: 48px 24px 28px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; max-width: 1280px; margin: 0 auto 36px; }
.footer-brand h3 { color: white; font-size: 1.3rem; font-weight: 800; margin-bottom: 10px; }
.footer-brand p { font-size: 0.9rem; line-height: 1.6; }
.footer-col h4 { color: white; font-size: 0.95rem; font-weight: 700; margin-bottom: 16px; }
.footer-col a { display: block; color: rgba(255,255,255,0.5); text-decoration: none; font-size: 0.875rem; margin-bottom: 10px; transition: color 0.2s; }
.footer-col a:hover { color: white; }
.footer-bottom {
    text-align: center; padding-top: 24px;
    border-top: 1px solid rgba(255,255,255,0.08);
    font-size: 0.85rem; max-width: 1280px; margin: 0 auto;
}

/* === 响应式 === */
@media (max-width: 1024px) {
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .testimonials-grid { grid-template-columns: repeat(2, 1fr); }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
    .nav-links { display: none; }
    .nav-links.open { display: flex; flex-direction: column; position: absolute; top: 72px; left: 0; right: 0; background: white; padding: 16px; border-bottom: 1px solid #E5E7EB; box-shadow: var(--shadow-lg); }
    .mobile-menu-btn { display: block; }
    .hero-container { grid-template-columns: 1fr; text-align: center; }
    .hero-title { font-size: 2.2rem; }
    .hero-desc { max-width: 100%; }
    .hero-buttons { justify-content: center; }
    .check-list { justify-content: center; }
    .hero-image { order: -1; }
    .hero-image img { max-width: 280px; }
    .features-grid { grid-template-columns: 1fr; }
    .testimonials-grid { grid-template-columns: 1fr; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
    .section-title { font-size: 1.8rem; }
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .cta-content h2 { font-size: 1.7rem; }
    .faq-question { font-size: 0.95rem; padding: 16px 18px; }
}
@media (max-width: 480px) {
    .hero { padding: 120px 16px 50px; }
    .hero-title { font-size: 1.7rem; }
    .hero-buttons { flex-direction: column; }
    .btn { justify-content: center; }
    .section { padding: 50px 16px; }
    .stats-grid { grid-template-columns: 1fr 1fr; gap: 20px; }
    .stat-number { font-size: 2rem; }
    .footer-grid { grid-template-columns: 1fr; }
}