/* ============================================
   北望ERP - 行业落地页样式
   纯静态版本 - 可直接放入nginx运行
   ============================================ */

/* --- Reset & Base --- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB',
               'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  color: #171717;
  background: #fff;
  line-height: 1.6;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* --- Scrollbar --- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: #171717; }
::-webkit-scrollbar-thumb { background: #3898EC; border-radius: 3px; }

/* --- Colors --- */
:root {
  --bg-dark: #171717;
  --bg-dark-deep: #0a0a0a;
  --bg-light: #f8f9fa;
  --accent: #3898EC;
  --accent-dark: #2b7bc9;
  --text-muted: #758696;
  --border-light: rgba(255,255,255,0.1);
}

/* --- Layout --- */
.container { max-width: 1280px; margin: 0 auto; padding: 0 24px; }
@media (max-width: 768px) { .container { padding: 0 16px; } }

/* --- Navbar --- */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  transition: all 0.3s ease;
}
.navbar.transparent { background: transparent; }
.navbar.scrolled { background: rgba(23,23,23,0.9); backdrop-filter: blur(10px); box-shadow: 0 4px 20px rgba(0,0,0,0.3); }
.navbar-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: flex; align-items: center; gap: 8px; font-size: 18px; font-weight: 600; color: #fff; }
.brand-logo { width: 32px; height: 32px; background: var(--accent); display: flex; align-items: center; justify-content: center; font-size: 12px; font-weight: 700; }
.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-links a {
  padding: 6px 10px; font-size: 14px; color: rgba(255,255,255,0.7);
  border-radius: 4px; transition: all 0.2s;
}
.nav-links a:hover, .nav-links a.active { color: var(--accent); background: rgba(255,255,255,0.05); }
.nav-actions { display: flex; align-items: center; gap: 12px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 10px 24px; font-size: 14px; font-weight: 500;
  border: none; cursor: pointer; transition: all 0.3s; white-space: nowrap;
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-dark); transform: scale(1.02); }
.btn-outline { background: transparent; color: #fff; border: 1px solid rgba(255,255,255,0.3); }
.btn-outline:hover { background: #fff; color: var(--bg-dark); }
.btn-white { background: #fff; color: var(--bg-dark); font-weight: 600; }
.btn-white:hover { background: var(--accent); color: #fff; }
.btn-lg { padding: 14px 40px; font-size: 16px; }

.menu-toggle { display: none; background: none; border: none; color: #fff; cursor: pointer; padding: 8px; }

@media (max-width: 1024px) {
  .nav-links { display: none; }
  .nav-actions .btn-outline { display: none; }
  .menu-toggle { display: block; }
}

/* Mobile Menu */
.mobile-menu {
  display: none; position: absolute; top: 64px; left: 0; right: 0;
  background: rgba(23,23,23,0.95); backdrop-filter: blur(10px);
  border-top: 1px solid var(--border-light); padding: 16px 24px;
}
.mobile-menu.active { display: block; }
.mobile-menu .mobile-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.mobile-menu a {
  padding: 10px 12px; font-size: 14px; color: rgba(255,255,255,0.7);
  border-radius: 4px; display: block;
}
.mobile-menu a:hover, .mobile-menu a.active { color: var(--accent); background: rgba(56,152,236,0.1); }
.mobile-menu .mobile-actions { display: flex; gap: 12px; margin-top: 16px; padding-top: 16px; border-top: 1px solid var(--border-light); }
.mobile-menu .mobile-actions a { flex: 1; text-align: center; }

/* --- Hero --- */
.hero {
  position: relative; min-height: 100vh; display: flex; align-items: center;
  overflow: hidden;
}
.hero-bg {
  position: absolute; inset: 0; z-index: 0;
}
.hero-bg img {
  width: 100%; height: 100%; object-fit: cover;
}
.hero-overlay {
  position: absolute; inset: 0;
  background: linear-gradient(to top, rgba(23,23,23,0.95) 0%, rgba(23,23,23,0.5) 50%, rgba(23,23,23,0.3) 100%);
}
.hero-gradient-r {
  position: absolute; inset: 0;
  background: linear-gradient(to right, rgba(23,23,23,0.85) 0%, transparent 60%);
}
.hero-content { position: relative; z-index: 2; padding-top: 96px; padding-bottom: 64px; max-width: 640px; }
.hero-label {
  display: flex; align-items: center; gap: 8px; margin-bottom: 24px;
  color: var(--accent); font-size: 14px; font-weight: 500; letter-spacing: 0.05em;
}
.hero-label .line { width: 32px; height: 1px; background: var(--accent); }
.hero h1 {
  font-size: 48px; font-weight: 700; line-height: 1.15;
  color: #fff; margin-bottom: 24px; letter-spacing: 0.02em;
}
.hero-subtitle { font-size: 18px; color: rgba(255,255,255,0.8); line-height: 1.8; margin-bottom: 40px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 16px; }
.hero-scroll {
  position: absolute; bottom: 32px; left: 50%; transform: translateX(-50%);
  animation: bounce 2s infinite; z-index: 2;
}
@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(8px); }
}

@media (max-width: 768px) {
  .hero h1 { font-size: 32px; }
  .hero-subtitle { font-size: 16px; }
  .hero-actions { flex-direction: column; }
  .hero-actions .btn { width: 100%; }
}

/* --- Section Common --- */
.section { padding: 96px 0; }
@media (max-width: 768px) { .section { padding: 64px 0; } }

.section-label {
  display: flex; align-items: center; gap: 8px; margin-bottom: 16px;
  color: var(--accent); font-size: 14px; font-weight: 500; letter-spacing: 0.05em;
}
.section-label .line { width: 32px; height: 1px; background: var(--accent); }
.section-label.center { justify-content: center; }
.section-label.center .line { display: inline-block; }

.section-title {
  font-size: 36px; font-weight: 700; line-height: 1.2;
  margin-bottom: 16px;
}
.section-title.light { color: #fff; }
.section-title.dark { color: var(--bg-dark); }

.section-desc { font-size: 16px; line-height: 1.8; }
.section-desc.light { color: rgba(255,255,255,0.7); }
.section-desc.dark { color: rgba(23,23,23,0.7); }

@media (max-width: 768px) {
  .section-title { font-size: 28px; }
}

/* --- Stats Cards --- */
.stats-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.stat-card {
  background: #f8f9fa; padding: 32px;
  border: 1px solid transparent; transition: all 0.3s;
}
.stat-card:hover {
  border-color: var(--accent);
  box-shadow: 0 0 20px rgba(56,152,236,0.12);
}
.stat-icon { color: var(--accent); margin-bottom: 16px; }
.stat-value { font-size: 36px; font-weight: 700; color: var(--bg-dark); margin-bottom: 8px; }
.stat-label { font-size: 14px; color: rgba(23,23,23,0.6); }

@media (max-width: 640px) {
  .stats-grid { grid-template-columns: 1fr; }
}

/* --- Feature Cards --- */
.features-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.feature-card {
  background: #fff; padding: 24px; border: 1px solid transparent;
  transition: all 0.3s; height: 100%;
}
.feature-card:hover {
  border-color: rgba(56,152,236,0.2);
  box-shadow: 0 10px 40px rgba(0,0,0,0.08);
}
.feature-icon-wrap {
  width: 48px; height: 48px; background: rgba(56,152,236,0.1);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 16px; transition: all 0.3s;
}
.feature-card:hover .feature-icon-wrap { background: var(--accent); }
.feature-icon-wrap svg { width: 24px; height: 24px; color: var(--accent); stroke-width: 1.5; }
.feature-card:hover .feature-icon-wrap svg { color: #fff; }
.feature-card h3 { font-size: 16px; font-weight: 600; color: var(--bg-dark); margin-bottom: 8px; }
.feature-card p { font-size: 13px; color: rgba(23,23,23,0.6); line-height: 1.7; }

@media (max-width: 1024px) { .features-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 480px) { .features-grid { grid-template-columns: 1fr; } }

/* --- Particle Grid Section --- */
.particle-section {
  position: relative; min-height: 80vh; display: flex; align-items: center;
  justify-content: center; overflow: hidden; background: var(--bg-dark);
}
.particle-section canvas {
  position: absolute; top: 0; left: 0; width: 100%; height: 100%; z-index: 0;
}
.particle-content {
  position: relative; z-index: 2; max-width: 640px;
  background: rgba(23,23,23,0.85); backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,0.1); padding: 48px;
  text-align: center;
}
@media (max-width: 768px) { .particle-content { padding: 32px 24px; margin: 0 16px; } }

/* --- Timeline --- */
.timeline { max-width: 720px; margin: 0 auto; position: relative; }
.timeline-line {
  position: absolute; left: 24px; top: 0; bottom: 0; width: 1px;
  background: rgba(56,152,236,0.3);
}
.timeline-item { position: relative; padding-left: 72px; padding-bottom: 48px; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-num {
  position: absolute; left: 0; top: 0; width: 48px; height: 48px;
  background: var(--accent); display: flex; align-items: center; justify-content: center;
  font-weight: 700; color: #fff; font-size: 16px;
}
.timeline-body {
  background: var(--bg-light); padding: 24px;
  border-left: 2px solid var(--accent);
}
.timeline-body h3 { font-size: 18px; font-weight: 600; color: var(--bg-dark); margin-bottom: 8px; }
.timeline-body p { font-size: 14px; color: rgba(23,23,23,0.6); line-height: 1.7; }

@media (max-width: 480px) {
  .timeline-item { padding-left: 56px; }
  .timeline-num { width: 36px; height: 36px; font-size: 14px; }
  .timeline-line { left: 18px; }
}

/* --- Testimonials --- */
.clients-row {
  display: flex; flex-wrap: wrap; justify-content: center; align-items: center;
  gap: 32px; opacity: 0.5; margin-bottom: 64px;
}
.clients-row span {
  font-size: 14px; font-weight: 500; color: rgba(255,255,255,0.4);
  letter-spacing: 0.05em; transition: color 0.3s; cursor: default;
}
.clients-row span:hover { color: rgba(255,255,255,0.8); }

.testimonials-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.testimonial-card {
  background: #222; padding: 24px; border: 1px solid rgba(255,255,255,0.05);
  transition: all 0.3s;
}
.testimonial-card:hover { border-color: rgba(56,152,236,0.2); }
.testimonial-card .quote-icon { color: var(--accent); margin-bottom: 16px; }
.testimonial-card p { color: rgba(255,255,255,0.8); line-height: 1.8; margin-bottom: 24px; font-size: 14px; }
.testimonial-author { display: flex; align-items: center; gap: 12px; }
.testimonial-author .avatar {
  width: 40px; height: 40px; background: rgba(56,152,236,0.2);
  display: flex; align-items: center; justify-content: center;
}
.testimonial-author .avatar svg { color: var(--accent); width: 18px; height: 18px; }
.testimonial-author .name { font-size: 14px; font-weight: 500; color: #fff; }
.testimonial-author .company { font-size: 12px; color: rgba(255,255,255,0.5); }

@media (max-width: 768px) { .testimonials-grid { grid-template-columns: 1fr; } }

/* --- SEO Keywords --- */
.seo-tags { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; margin-bottom: 48px; }
.seo-tag {
  padding: 8px 20px; background: #fff; border: 1px solid rgba(23,23,23,0.1);
  font-size: 14px; color: rgba(23,23,23,0.7); transition: all 0.3s; cursor: default;
}
.seo-tag:hover { color: var(--accent); border-color: rgba(56,152,236,0.3); }

.seo-links { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; max-width: 720px; margin: 0 auto; }
.seo-link {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 20px; background: #fff; border: 1px solid rgba(23,23,23,0.1);
  font-size: 14px; color: var(--bg-dark); transition: all 0.3s;
}
.seo-link:hover { color: var(--accent); border-color: var(--accent); }
.seo-link svg { width: 16px; height: 16px; color: rgba(23,23,23,0.3); transition: color 0.3s; }
.seo-link:hover svg { color: var(--accent); }

@media (max-width: 640px) { .seo-links { grid-template-columns: 1fr; } }

/* --- CTA Section --- */
.cta-section {
  position: relative; padding: 120px 0; overflow: hidden;
  background: var(--bg-dark);
}
.cta-dots {
  position: absolute; inset: 0; opacity: 0.05;
  background-image: radial-gradient(circle at 1px 1px, #3898EC 1px, transparent 0);
  background-size: 40px 40px;
}
.cta-content { position: relative; z-index: 2; text-align: center; max-width: 800px; margin: 0 auto; }
.cta-content h2 { font-size: 40px; font-weight: 700; color: #fff; margin-bottom: 24px; }
.cta-content > p { font-size: 18px; color: rgba(255,255,255,0.7); margin-bottom: 40px; }
.cta-actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 16px; margin-bottom: 48px; }
.cta-badges { display: flex; flex-wrap: wrap; justify-content: center; gap: 32px; }
.cta-badge { display: flex; align-items: center; gap: 8px; color: rgba(255,255,255,0.6); font-size: 14px; }
.cta-badge svg { color: var(--accent); width: 18px; height: 18px; }

@media (max-width: 768px) {
  .cta-section { padding: 80px 0; }
  .cta-content h2 { font-size: 28px; }
  .cta-actions { flex-direction: column; align-items: center; }
  .cta-actions .btn { width: 100%; max-width: 320px; }
}

/* --- Footer --- */
.footer { background: var(--bg-dark-deep); border-top: 1px solid rgba(255,255,255,0.05); padding: 80px 0 0; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 48px; }
.footer-brand p { font-size: 14px; color: var(--text-muted); line-height: 1.8; margin-top: 16px; }
.footer-col h4 { font-size: 16px; font-weight: 600; color: #fff; margin-bottom: 20px; }
.footer-col ul li { margin-bottom: 12px; }
.footer-col ul li a, .footer-col ul li span {
  font-size: 14px; color: var(--text-muted); transition: color 0.3s;
}
.footer-col ul li a:hover { color: var(--accent); }
.footer-bottom {
  margin-top: 64px; padding: 24px 0;
  border-top: 1px solid rgba(255,255,255,0.05);
  display: flex; justify-content: space-between; align-items: center;
}
.footer-bottom p { font-size: 12px; color: var(--text-muted); }
.footer-bottom-links { display: flex; gap: 24px; }
.footer-bottom-links span { font-size: 12px; color: var(--text-muted); cursor: default; transition: color 0.3s; }
.footer-bottom-links span:hover { color: #fff; }

@media (max-width: 768px) {
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .footer-bottom { flex-direction: column; gap: 12px; text-align: center; }
}
@media (max-width: 480px) {
  .footer-grid { grid-template-columns: 1fr; }
}

/* --- Scroll Reveal --- */
.reveal {
  opacity: 0; transform: translateY(40px);
  transition: opacity 0.8s cubic-bezier(0.16,1,0.3,1), transform 0.8s cubic-bezier(0.16,1,0.3,1);
}
.reveal.visible { opacity: 1; transform: translateY(0); }
.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }
.reveal-delay-5 { transition-delay: 0.5s; }

/* --- Utility --- */
.bg-white { background: #fff; }
.bg-light { background: var(--bg-light); }
.bg-dark { background: var(--bg-dark); }
.text-center { text-align: center; }
.grid-12 { display: grid; grid-template-columns: repeat(12, 1fr); gap: 24px; }
.col-5 { grid-column: span 5; }
.col-7 { grid-column: span 7; }
@media (max-width: 768px) {
  .grid-12 { grid-template-columns: 1fr; }
  .col-5, .col-7 { grid-column: span 1; }
}