:root {
  --primary: #6C3CE1;
  --primary-light: #8B5CF6;
  --accent: #FF6B4A;
  --dark: #0f0a1e;
  --dark-2: #1a1230;
  --text: #1e293b;
  --text-light: #64748b;
  --light-bg: #f8f6ff;
  --white: #ffffff;
  --gradient-hero: linear-gradient(135deg, #1a0533 0%, #2d1b69 40%, #0f0a1e 100%);
  --gradient-primary: linear-gradient(135deg, #6C3CE1, #8B5CF6);
  --radius: 16px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, 'PingFang SC', 'Microsoft YaHei', 'Segoe UI', sans-serif;
  color: var(--text);
  line-height: 1.7;
  background: var(--white);
  overflow-x: hidden;
}

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

img { max-width: 100%; height: auto; display: block; }

a { text-decoration: none; color: inherit; }

ul { list-style: none; }

/* ===== NAVBAR ===== */
.navbar {
  position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
  background: rgba(255,255,255,0.95); backdrop-filter: blur(12px);
  box-shadow: 0 1px 12px rgba(0,0,0,0.06);
  transition: box-shadow 0.3s;
}
.nav-wrap {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.logo { font-size: 1.6rem; font-weight: 800; color: var(--primary); }
.nav-links { display: flex; gap: 32px; align-items: center; }
.nav-links li a {
  font-size: 0.95rem; font-weight: 500; color: var(--text-light);
  transition: color 0.2s;
}
.nav-links li a:hover { color: var(--primary); }
.menu-toggle {
  display: none; flex-direction: column; gap: 5px; cursor: pointer;
  background: none; border: none; padding: 4px;
}
.menu-toggle span {
  display: block; width: 24px; height: 2px; background: var(--text);
  border-radius: 2px; transition: transform 0.3s, opacity 0.3s;
}
.menu-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== HERO ===== */
.hero {
  padding: 140px 0 100px; background: var(--gradient-hero);
  color: var(--white); text-align: center; position: relative; overflow: hidden;
}
.hero::before, .hero::after {
  content: ''; position: absolute; border-radius: 50%;
  background: radial-gradient(circle, rgba(108,60,225,0.25), transparent 70%);
}
.hero::before { width: 600px; height: 600px; top: -200px; right: -150px; }
.hero::after { width: 400px; height: 400px; bottom: -150px; left: -100px; }
.hero-content { position: relative; z-index: 2; max-width: 800px; margin: 0 auto; }
.hero h1 { font-size: 3rem; font-weight: 800; line-height: 1.25; margin-bottom: 20px; }
.hero-sub { font-size: 1.15rem; opacity: 0.88; margin-bottom: 36px; line-height: 1.8; }
.hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.floating-notes { position: absolute; inset: 0; z-index: 1; pointer-events: none; }
.note {
  position: absolute; font-size: 2rem; opacity: 0.12; color: #fff;
  animation: floatNote 6s ease-in-out infinite;
}
.n1 { top: 15%; left: 10%; animation-delay: 0s; }
.n2 { top: 30%; right: 12%; animation-delay: 1.5s; }
.n3 { bottom: 20%; left: 20%; animation-delay: 3s; }
.n4 { bottom: 30%; right: 18%; animation-delay: 4.5s; }
@keyframes floatNote {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-20px) rotate(10deg); }
}

/* ===== BUTTONS ===== */
.btn-primary {
  display: inline-block; padding: 14px 36px; border-radius: 30px;
  background: var(--accent); color: #fff; font-weight: 600; font-size: 1rem;
  transition: transform 0.2s, box-shadow 0.2s; border: none; cursor: pointer;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(255,107,74,0.35); }
.btn-secondary {
  display: inline-block; padding: 14px 36px; border-radius: 30px;
  background: transparent; color: #fff; font-weight: 600; font-size: 1rem;
  border: 2px solid rgba(255,255,255,0.4); transition: all 0.2s; cursor: pointer;
}
.btn-secondary:hover { background: rgba(255,255,255,0.15); border-color: #fff; }

/* ===== STATS ===== */
.stats { background: var(--white); padding: 0; position: relative; z-index: 10; margin-top: -48px; }
.stats-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  background: var(--white); border-radius: var(--radius); padding: 40px 24px;
  box-shadow: 0 12px 40px rgba(0,0,0,0.08);
}
.stat-item { text-align: center; padding: 12px 0; }
.stat-num { display: block; font-size: 2.2rem; font-weight: 800; color: var(--primary); }
.stat-label { display: block; font-size: 0.95rem; color: var(--text-light); margin-top: 4px; }
/* ===== SECTION TITLES ===== */
.section-title { text-align: center; margin-bottom: 56px; }
.section-title h2 { font-size: 2.2rem; font-weight: 800; color: var(--dark); margin-bottom: 12px; }
.section-title p { font-size: 1.05rem; color: var(--text-light); max-width: 600px; margin: 0 auto; }

/* ===== FEATURES ===== */
.features { padding: 96px 0; background: var(--light-bg); }
.features-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px;
}
.feature-card {
  background: var(--white); padding: 32px 28px; border-radius: var(--radius);
  box-shadow: 0 4px 20px rgba(0,0,0,0.04); border: 1px solid #eee;
  transition: transform 0.25s, box-shadow 0.25s;
}
.feature-card:hover {
  transform: translateY(-6px); box-shadow: 0 12px 36px rgba(108,60,225,0.1);
  border-color: var(--primary-light);
}
.feature-icon { font-size: 2.2rem; margin-bottom: 16px; }
.feature-card h3 { font-size: 1.2rem; font-weight: 700; color: var(--dark); margin-bottom: 10px; }
.feature-card p { font-size: 0.95rem; color: var(--text-light); line-height: 1.75; }

/* ===== HOW IT WORKS ===== */
.how-it-works { padding: 96px 0; background: var(--white); }
.steps-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 32px; }
.step { text-align: center; position: relative; }
.step-num {
  width: 56px; height: 56px; border-radius: 50%; margin: 0 auto 20px;
  background: var(--gradient-primary); color: #fff;
  font-size: 1.3rem; font-weight: 800;
  display: flex; align-items: center; justify-content: center;
}
.step-connector {
  position: absolute; top: 28px; left: calc(50% + 32px); width: calc(100% - 64px);
  height: 2px; background: linear-gradient(90deg, var(--primary-light), #ddd);
}
.step:last-child .step-connector { display: none; }
.step h3 { font-size: 1.1rem; font-weight: 700; color: var(--dark); margin-bottom: 10px; }
.step p { font-size: 0.9rem; color: var(--text-light); line-height: 1.7; }

/* ===== USE CASES ===== */
.use-cases { padding: 96px 0; background: var(--light-bg); }
.cases-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 28px; }
.case-card {
  background: var(--white); border-radius: var(--radius); overflow: hidden;
  box-shadow: 0 4px 20px rgba(0,0,0,0.04); border: 1px solid #eee;
  transition: transform 0.25s, box-shadow 0.25s;
}
.case-card:hover { transform: translateY(-4px); box-shadow: 0 12px 36px rgba(0,0,0,0.08); }
.case-icon { font-size: 2.4rem; padding: 28px 28px 0; }
.case-body { padding: 20px 28px 28px; }
.case-card h3 { font-size: 1.15rem; font-weight: 700; color: var(--dark); margin-bottom: 10px; }
.case-card p { font-size: 0.93rem; color: var(--text-light); line-height: 1.75; }
/* ===== TESTIMONIALS ===== */
.testimonials { padding: 96px 0; background: var(--white); }
.testimonials-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.testimonial-card {
  background: var(--light-bg); padding: 32px 28px; border-radius: var(--radius);
  border: 1px solid #ede8f5; position: relative;
  transition: transform 0.25s, box-shadow 0.25s;
}
.testimonial-card:hover { transform: translateY(-4px); box-shadow: 0 12px 30px rgba(108,60,225,0.08); }
.quote-mark { font-size: 3.5rem; color: var(--primary-light); opacity: 0.3; line-height: 1; margin-bottom: 8px; }
.quote-text { font-size: 0.95rem; color: var(--text); line-height: 1.8; margin-bottom: 20px; }
.quote-author { display: flex; align-items: center; gap: 12px; }
.avatar {
  width: 44px; height: 44px; border-radius: 50%; color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 1rem; flex-shrink: 0;
}
.author-title { font-size: 0.82rem; color: var(--text-light); }
.stars { color: #f59e0b; margin-top: 14px; font-size: 0.9rem; letter-spacing: 2px; }

/* ===== FAQ ===== */
.faq { padding: 96px 0; background: var(--light-bg); }
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  background: var(--white); border-radius: 12px; margin-bottom: 12px;
  border: 1px solid #eee; overflow: hidden;
  transition: box-shadow 0.2s;
}
.faq-item:hover { box-shadow: 0 4px 16px rgba(0,0,0,0.06); }
.faq-question {
  display: flex; justify-content: space-between; align-items: center;
  padding: 20px 24px; font-size: 1.05rem; font-weight: 600;
  color: var(--dark); cursor: pointer; list-style: none;
}
.faq-question::-webkit-details-marker { display: none; }
.faq-toggle {
  font-size: 1.4rem; color: var(--primary); transition: transform 0.3s;
  font-weight: 300; flex-shrink: 0; margin-left: 16px;
}
details[open] .faq-toggle { transform: rotate(45deg); }
.faq-answer { padding: 0 24px 20px; }
.faq-answer p { font-size: 0.95rem; color: var(--text-light); line-height: 1.85; }

/* ===== FOOTER ===== */
footer { background: var(--dark); color: #fff; padding: 64px 0 0; }
.footer-grid {
  display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px;
  padding-bottom: 40px;
}
.footer-logo { font-size: 1.5rem; font-weight: 800; color: #fff; margin-bottom: 12px; }
.footer-section p { color: #94a3b8; font-size: 0.9rem; line-height: 1.7; margin-bottom: 16px; }
.footer-section h3 { font-size: 1rem; font-weight: 700; margin-bottom: 16px; color: #e2e8f0; }
.footer-section a {
  display: block; color: #94a3b8; font-size: 0.9rem; padding: 4px 0;
  transition: color 0.2s;
}
.footer-section a:hover { color: #fff; }
.social-links { display: flex; gap: 10px; margin-top: 8px; }
.social-links a {
  width: 36px; height: 36px; border-radius: 50%;
  background: rgba(255,255,255,0.08); display: flex;
  align-items: center; justify-content: center;
  font-size: 0.9rem; transition: background 0.2s, transform 0.2s;
}
.social-links a:hover { background: var(--primary); transform: translateY(-2px); }
.footer-bottom {
  text-align: center; padding: 24px 0; margin-top: 8px;
  border-top: 1px solid rgba(255,255,255,0.08);
  color: #64748b; font-size: 0.85rem;
}
/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .steps-grid { grid-template-columns: repeat(2, 1fr); }
  .step-connector { display: none; }
  .testimonials-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .nav-links {
    display: none; flex-direction: column; position: absolute;
    top: 64px; left: 0; width: 100%; background: var(--white);
    box-shadow: 0 8px 24px rgba(0,0,0,0.1); padding: 24px;
    gap: 20px;
  }
  .nav-links.open { display: flex; }
  .menu-toggle { display: flex; }
  .hero { padding: 120px 0 72px; }
  .hero h1 { font-size: 2rem; }
  .hero-sub { font-size: 1rem; }
  .stats { margin-top: -32px; }
  .stats-grid { grid-template-columns: 1fr; gap: 16px; padding: 28px 20px; }
  .features-grid { grid-template-columns: 1fr; }
  .steps-grid { grid-template-columns: 1fr; gap: 24px; }
  .cases-grid { grid-template-columns: 1fr; }
  .testimonials-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .section-title h2 { font-size: 1.7rem; }
  .hero-btns { flex-direction: column; align-items: center; }
  .btn-primary, .btn-secondary { width: 100%; max-width: 280px; text-align: center; }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 1.6rem; }
  .stat-num { font-size: 1.8rem; }
  .feature-card { padding: 24px 20px; }
  .testimonial-card { padding: 24px 20px; }
  .faq-question { font-size: 0.95rem; padding: 16px 18px; }
  .faq-answer { padding: 0 18px 16px; }
}