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

:root {
  --primary-color: #1e40af;
  --primary-hover: #1e3a8a;
  --text-dark: #1f2937;
  --text-light: #6b7280;
  --bg-light: #f9fafb;
  --bg-white: #ffffff;
  --border-color: #e5e7eb;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
    Ubuntu, Cantarell, sans-serif;
  line-height: 1.6;
  color: var(--text-dark);
  background-color: var(--bg-light);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Hero Section */
.hero {
  background: linear-gradient(135deg, #1e40af 0%, #3b82f6 100%);
  color: white;
  padding: 80px 20px;
  text-align: center;
  min-height: 500px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-content {
  max-width: 800px;
}

.logo {
  width: 120px;
  height: 120px;
  border-radius: 20px;
  margin-bottom: 30px;
  box-shadow: var(--shadow-lg);
  border: 4px solid rgba(255, 255, 255, 0.2);
}

.hero h1 {
  font-size: 3.5rem;
  font-weight: 700;
  margin-bottom: 20px;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.hero-subtitle {
  font-size: 1.25rem;
  margin-bottom: 40px;
  opacity: 0.95;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.download-btn {
  background-color: white;
  color: var(--primary-color);
  border: none;
  padding: 16px 40px;
  font-size: 1.1rem;
  font-weight: 600;
  border-radius: 50px;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-lg);
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.download-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 15px 25px -5px rgba(0, 0, 0, 0.2);
}

.download-btn:active {
  transform: translateY(0);
}

/* Features Section */
.features {
  padding: 80px 20px;
  background-color: var(--bg-white);
}

.features h2 {
  text-align: center;
  font-size: 2.5rem;
  margin-bottom: 60px;
  color: var(--text-dark);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 40px;
}

.feature-card {
  background: var(--bg-white);
  padding: 40px 30px;
  border-radius: 16px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
  text-align: center;
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.feature-icon {
  width: 80px;
  height: 80px;
  background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 25px;
}

.feature-icon svg {
  stroke: white;
}

.feature-card h3 {
  font-size: 1.5rem;
  margin-bottom: 15px;
  color: var(--text-dark);
}

.feature-card p {
  color: var(--text-light);
  font-size: 1rem;
  line-height: 1.7;
}

/* Preview Section */
.preview {
  padding: 80px 20px;
  background-color: var(--bg-light);
}

.preview h2 {
  text-align: center;
  font-size: 2.5rem;
  margin-bottom: 60px;
  color: var(--text-dark);
}

.carousel-container {
  position: relative;
  max-width: 1000px;
  margin: 0 auto;
}

.carousel {
  overflow: hidden;
  border-radius: 20px;
  box-shadow: var(--shadow-lg);
}

.carousel-track {
  display: flex;
  transition: transform 0.5s ease;
}

.carousel-slide {
  min-width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  background: var(--bg-white);
  padding: 20px;
}

.carousel-slide img {
  max-width: 100%;
  max-height: 600px;
  object-fit: contain;
  border-radius: 12px;
}

.carousel-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(255, 255, 255, 0.9);
  border: none;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  font-size: 2rem;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: var(--shadow);
  color: var(--primary-color);
  z-index: 10;
}

.carousel-btn:hover {
  background: white;
  transform: translateY(-50%) scale(1.1);
}

.carousel-btn.prev {
  left: -25px;
}

.carousel-btn.next {
  right: -25px;
}

.carousel-hint {
  text-align: center;
  margin-top: 20px;
  color: var(--text-light);
  font-size: 1rem;
}

/* Footer */
.footer {
  background-color: var(--text-dark);
  color: white;
  padding: 40px 20px;
  text-align: center;
}

.footer p {
  margin: 5px 0;
  opacity: 0.9;
}

/* Responsive */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 2.5rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .features h2,
  .preview h2 {
    font-size: 2rem;
  }

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

  .carousel-btn {
    width: 40px;
    height: 40px;
    font-size: 1.5rem;
  }

  .carousel-btn.prev {
    left: 5px;
  }

  .carousel-btn.next {
    right: 5px;
  }

  .logo {
    width: 100px;
    height: 100px;
  }
}

@media (max-width: 480px) {
  .hero {
    padding: 60px 20px;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .download-btn {
    padding: 14px 30px;
    font-size: 1rem;
  }

  .features,
  .preview {
    padding: 60px 20px;
  }
}