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

:root {
  --primary: #4F46E5;
  --primary-dark: #4338CA;
  --secondary: #10B981;
  --dark: #1F2937;
  --gray: #6B7280;
  --light: #F9FAFB;
  --white: #FFFFFF;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  color: var(--dark);
  line-height: 1.6;
}

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

/* ==================== Header ==================== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  z-index: 100;
  border-bottom: 1px solid #E5E7EB;
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
}

.logo-icon {
  width: 36px;
  height: 36px;
}

.nav {
  display: flex;
  gap: 2rem;
}

.nav a {
  color: var(--gray);
  font-weight: 500;
  transition: color 0.2s;
}

.nav a:hover {
  color: var(--primary);
}

.header-btn {
  background: var(--primary);
  color: white;
  padding: 0.6rem 1.5rem;
  border-radius: 8px;
  font-weight: 500;
  transition: background 0.2s;
}

.header-btn:hover {
  background: var(--primary-dark);
}

/* ==================== Hero ==================== */
.hero {
  padding: 8rem 2rem 4rem;
  background: linear-gradient(135deg, #EEF2FF 0%, #E0E7FF 100%);
  text-align: center;
}

.hero h1 {
  font-size: 3.5rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
  background: linear-gradient(135deg, var(--primary) 0%, #7C3AED 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  font-size: 1.25rem;
  color: var(--gray);
  max-width: 600px;
  margin: 0 auto 2rem;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  padding: 1rem 2rem;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
}

.btn-primary {
  background: var(--primary);
  color: white;
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(79, 70, 229, 0.3);
}

.btn-secondary {
  background: white;
  color: var(--dark);
  border: 2px solid #E5E7EB;
}

.btn-secondary:hover {
  border-color: var(--primary);
  color: var(--primary);
}

/* ==================== Hero Demo ==================== */
.hero-image {
  max-width: 900px;
  margin: 3rem auto 0;
}

.demo-container {
  background: #1a1a2e;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 25px 50px rgba(0, 0, 0, 0.25);
}

.demo-header {
  background: #16162a;
  padding: 12px 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.demo-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.demo-dot.red { background: #ff5f57; }
.demo-dot.yellow { background: #febc2e; }
.demo-dot.green { background: #28c840; }

.demo-title {
  color: #666;
  font-size: 13px;
  margin-left: auto;
  margin-right: auto;
}

.demo-content {
  display: flex;
  padding: 20px;
  gap: 20px;
  min-height: 350px;
}

.demo-sidebar {
  width: 80px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.demo-thumb {
  background: #2a2a4a;
  border-radius: 6px;
  height: 60px;
  border: 2px solid transparent;
  transition: all 0.3s;
}

.demo-thumb.active {
  border-color: var(--primary);
  box-shadow: 0 0 0 2px rgba(79, 70, 229, 0.3);
}

.demo-main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.demo-page {
  background: white;
  width: 100%;
  max-width: 600px;
  height: 300px;
  border-radius: 8px;
  position: relative;
  display: flex;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.demo-split-line {
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 4px;
  background: var(--primary);
  cursor: ew-resize;
  z-index: 10;
}

.demo-split-line::before {
  content: '⋮';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: var(--primary);
  color: white;
  width: 24px;
  height: 40px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
}

.demo-left, .demo-right {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  font-weight: 600;
  color: #ccc;
}

.demo-left {
  background: linear-gradient(135deg, #f8f9ff 0%, #eef1ff 100%);
  border-radius: 8px 0 0 8px;
}

.demo-right {
  background: linear-gradient(135deg, #fff8f8 0%, #ffeeee 100%);
  border-radius: 0 8px 8px 0;
}

/* ==================== Features ==================== */
.features {
  padding: 5rem 2rem;
  background: var(--white);
}

.section-title {
  text-align: center;
  margin-bottom: 3rem;
}

.section-title h2 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.section-title p {
  color: var(--gray);
  font-size: 1.1rem;
}

.features-grid {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.feature-card {
  padding: 2rem;
  border-radius: 16px;
  background: var(--light);
  transition: all 0.3s;
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

/* ==================== Feature Icons ==================== */
.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--primary) 0%, #7C3AED 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.5rem;
}

.feature-icon svg {
  width: 28px;
  height: 28px;
  color: white;
}

.feature-card h3 {
  font-size: 1.25rem;
  margin-bottom: 0.75rem;
}

.feature-card p {
  color: var(--gray);
}

/* ==================== Platforms ==================== */
.platforms {
  padding: 5rem 2rem;
  background: var(--light);
}

.platforms-grid {
  max-width: 1000px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}

.platform-card {
  background: white;
  border-radius: 20px;
  padding: 2.5rem;
  text-align: center;
  transition: all 0.3s;
  border: 2px solid transparent;
}

.platform-card:hover {
  border-color: var(--primary);
  transform: translateY(-5px);
  box-shadow: 0 20px 40px rgba(79, 70, 229, 0.1);
}

.platform-icon {
  width: 80px;
  height: 80px;
  margin: 0 auto 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
}

.platform-card h3 {
  font-size: 1.5rem;
  margin-bottom: 0.5rem;
}

.platform-card .desc {
  color: var(--gray);
  margin-bottom: 1.5rem;
}

.platform-buttons {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.btn-outline {
  background: white;
  color: var(--dark);
  border: 2px solid #E5E7EB;
}

.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.btn-icon {
  margin-right: 0.5rem;
}

.qrcode {
  width: 120px;
  height: 120px;
  margin: 0 auto 1.5rem;
  background: #f9fafb;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 2px dashed #e5e7eb;
}

/* ==================== How It Works ==================== */
.how-it-works {
  padding: 5rem 2rem;
  background: white;
}

.steps {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.step {
  display: flex;
  gap: 2rem;
  align-items: flex-start;
}

.step-number {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: var(--primary);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  font-weight: 700;
  flex-shrink: 0;
}

.step-content h3 {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
}

.step-content p {
  color: var(--gray);
}

/* ==================== CTA ==================== */
.cta {
  padding: 5rem 2rem;
  background: linear-gradient(135deg, var(--primary) 0%, #7C3AED 100%);
  text-align: center;
  color: white;
}

.cta h2 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.cta p {
  opacity: 0.9;
  margin-bottom: 2rem;
  font-size: 1.1rem;
}

.cta .btn {
  background: white;
  color: var(--primary);
  font-weight: 600;
  padding: 1rem 2.5rem;
}

.cta .btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

/* ==================== Footer ==================== */
.footer {
  padding: 3rem 2rem;
  background: var(--dark);
  color: white;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-links {
  display: flex;
  gap: 2rem;
}

.footer-links a {
  color: #9CA3AF;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: white;
}

.copyright {
  color: #9CA3AF;
}

/* ==================== Responsive ==================== */
@media (max-width: 768px) {
  .header-inner {
    padding: 1rem;
  }
  
  .nav {
    display: none;
  }
  
  .hero h1 {
    font-size: 2.5rem;
  }
  
  .hero p {
    font-size: 1rem;
  }
  
  .section-title h2 {
    font-size: 2rem;
  }
  
  .step {
    flex-direction: column;
    text-align: center;
  }
  
  .step-number {
    margin: 0 auto;
  }
  
  .footer-inner {
    flex-direction: column;
    text-align: center;
  }
}