/* ===================== 基础变量 ===================== */
:root {
  --primary: #4f46e5;
  --primary-light: #6366f1;
  --primary-dark: #3730a3;
  --accent: #06b6d4;
  --accent-glow: rgba(6, 182, 212, 0.3);
  --bg: #0b0f1a;
  --bg-card: #111827;
  --bg-card-hover: #1e293b;
  --surface: #1e293b;
  --text: #e2e8f0;
  --text-muted: #94a3b8;
  --text-bright: #f8fafc;
  --border: rgba(148, 163, 184, 0.1);
  --radius: 16px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font: 'Noto Sans SC', system-ui, -apple-system, sans-serif;
}

/* ===================== 重置 & 基础 ===================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

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

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

.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: 20px 0;
  transition: var(--transition);
}

.navbar.scrolled {
  background: rgba(11, 15, 26, 0.92);
  backdrop-filter: blur(16px);
  padding: 12px 0;
  box-shadow: 0 1px 0 var(--border);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.2rem;
}

.logo-icon { font-size: 1.6rem; }
.logo-text { color: var(--text-bright); }

.nav-links {
  display: flex;
  gap: 32px;
}

.nav-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: var(--transition);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: var(--transition);
}

.nav-links a:hover {
  color: var(--text-bright);
}

.nav-links a:hover::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: var(--transition);
}

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

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 20% 40%, rgba(79, 70, 229, 0.15), transparent),
    radial-gradient(ellipse 60% 50% at 80% 60%, rgba(6, 182, 212, 0.12), transparent),
    radial-gradient(ellipse 40% 40% at 50% 20%, rgba(139, 92, 246, 0.08), transparent);
  animation: heroPulse 8s ease-in-out infinite alternate;
}

@keyframes heroPulse {
  0%   { opacity: 1; transform: scale(1); }
  100% { opacity: 0.7; transform: scale(1.05); }
}

.hero-content {
  position: relative;
  text-align: center;
  padding: 120px 24px 80px;
}

.hero-title {
  font-size: clamp(2.4rem, 6vw, 4.2rem);
  font-weight: 900;
  line-height: 1.2;
  margin-bottom: 24px;
}

.hero-line {
  display: block;
  color: var(--text-bright);
}

.hero-line.accent {
  background: linear-gradient(135deg, var(--primary-light), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 640px;
  margin: 0 auto 40px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  padding: 14px 32px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: 50px;
  transition: var(--transition);
  cursor: pointer;
  border: none;
  font-family: var(--font);
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: #fff;
  box-shadow: 0 4px 20px rgba(79, 70, 229, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(79, 70, 229, 0.5);
}

.btn-outline {
  background: transparent;
  color: var(--text);
  border: 1.5px solid var(--border);
}

.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
}

.hero-scroll {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--text-muted);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
}

.scroll-indicator {
  width: 20px;
  height: 32px;
  border: 2px solid var(--text-muted);
  border-radius: 10px;
  position: relative;
}

.scroll-indicator::after {
  content: '';
  position: absolute;
  top: 6px;
  left: 50%;
  transform: translateX(-50%);
  width: 3px;
  height: 8px;
  background: var(--accent);
  border-radius: 2px;
  animation: scrollBounce 1.5s ease-in-out infinite;
}

@keyframes scrollBounce {
  0%, 100% { transform: translateX(-50%) translateY(0); opacity: 1; }
  50%      { transform: translateX(-50%) translateY(8px); opacity: 0.3; }
}

/* ===================== 通用 Section ===================== */
.section {
  padding: 100px 0;
}

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

.section-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 900;
  color: var(--text-bright);
}

/* ===================== 关于我们 ===================== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.about-text p {
  margin-bottom: 16px;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.9;
}

.about-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 20px;
  text-align: center;
  transition: var(--transition);
}

.stat-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(6, 182, 212, 0.3);
  transform: translateY(-4px);
}

.stat-number {
  font-size: 1.5rem;
  font-weight: 900;
  background: linear-gradient(135deg, var(--primary-light), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 4px;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ===================== 核心业务 ===================== */
.business {
  background: linear-gradient(180deg, transparent, rgba(17, 24, 39, 0.5), transparent);
}

.business-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

.business-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 48px 36px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.business-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  border-radius: var(--radius) var(--radius) 0 0;
  transition: var(--transition);
}

.business-card.slg::before {
  background: linear-gradient(90deg, var(--primary), var(--primary-light));
}

.business-card.casual::before {
  background: linear-gradient(90deg, var(--accent), #34d399);
}

.business-card:hover {
  transform: translateY(-6px);
  border-color: rgba(148, 163, 184, 0.2);
  box-shadow: var(--shadow);
}

.card-icon {
  font-size: 2.8rem;
  margin-bottom: 20px;
}

.business-card h3 {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-bright);
  margin-bottom: 16px;
}

.business-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.8;
  margin-bottom: 24px;
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.card-tags li {
  padding: 6px 14px;
  font-size: 0.8rem;
  background: rgba(99, 102, 241, 0.1);
  color: var(--primary-light);
  border-radius: 20px;
  border: 1px solid rgba(99, 102, 241, 0.15);
}

.business-card.casual .card-tags li {
  background: rgba(6, 182, 212, 0.1);
  color: var(--accent);
  border-color: rgba(6, 182, 212, 0.15);
}

/* ===================== 优势 ===================== */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.adv-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 28px;
  transition: var(--transition);
}

.adv-card:hover {
  background: var(--bg-card-hover);
  transform: translateY(-4px);
  border-color: rgba(6, 182, 212, 0.25);
}

.adv-index {
  font-size: 2.2rem;
  font-weight: 900;
  background: linear-gradient(135deg, var(--primary-light), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 16px;
  line-height: 1;
}

.adv-card h4 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-bright);
  margin-bottom: 10px;
}

.adv-card p {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* ===================== 联系我们 ===================== */
.contact {
  background: linear-gradient(180deg, transparent, rgba(17, 24, 39, 0.5), transparent);
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.contact-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 28px;
  text-align: center;
  transition: var(--transition);
}

.contact-card:hover {
  background: var(--bg-card-hover);
  transform: translateY(-4px);
}

.contact-icon {
  font-size: 2.4rem;
  margin-bottom: 16px;
}

.contact-card h4 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-bright);
  margin-bottom: 10px;
}

.contact-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* ===================== 页脚 ===================== */
.footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
}

.footer-copy {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* ===================== 入场动画 ===================== */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 错开动画 */
.about-stats .stat-card:nth-child(1) { transition-delay: 0.05s; }
.about-stats .stat-card:nth-child(2) { transition-delay: 0.1s; }
.about-stats .stat-card:nth-child(3) { transition-delay: 0.15s; }
.about-stats .stat-card:nth-child(4) { transition-delay: 0.2s; }

.adv-card:nth-child(1) { transition-delay: 0.05s; }
.adv-card:nth-child(2) { transition-delay: 0.1s; }
.adv-card:nth-child(3) { transition-delay: 0.15s; }
.adv-card:nth-child(4) { transition-delay: 0.2s; }

.contact-card:nth-child(1) { transition-delay: 0.05s; }
.contact-card:nth-child(2) { transition-delay: 0.1s; }
.contact-card:nth-child(3) { transition-delay: 0.15s; }

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

@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 70%;
    max-width: 300px;
    height: 100vh;
    background: rgba(11, 15, 26, 0.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 80px 32px;
    gap: 24px;
    transition: var(--transition);
  }

  .nav-links.open {
    right: 0;
  }

  .nav-toggle {
    display: flex;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }

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

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

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

  .business-card {
    padding: 32px 24px;
  }

  .footer-inner {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }

  .hero-content {
    padding: 100px 16px 60px;
  }
}