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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  color: #333;
  background: #fff;
  line-height: 1.6;
}

/* --- Hero --- */
.hero {
  text-align: center;
  padding: 80px 24px 60px;
  background: linear-gradient(135deg, #4a90d9 0%, #357abd 100%);
  color: #fff;
}

.hero-title {
  font-size: 48px;
  font-weight: 700;
  letter-spacing: 2px;
  margin-bottom: 12px;
}

.hero-subtitle {
  font-size: 20px;
  font-weight: 400;
  margin-bottom: 16px;
  opacity: 0.95;
}

.hero-description {
  font-size: 15px;
  max-width: 520px;
  margin: 0 auto 32px;
  opacity: 0.9;
  line-height: 1.7;
}

.hero-cta {
  display: inline-block;
  padding: 14px 36px;
  font-size: 16px;
  font-weight: 600;
  color: #4a90d9;
  background: #fff;
  border: none;
  border-radius: 28px;
  text-decoration: none;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  transition: transform 0.15s, box-shadow 0.15s;
}

.hero-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
}

.hero-cta:active {
  transform: translateY(0);
}

/* --- Section common --- */
.section {
  padding: 64px 24px;
  max-width: 960px;
  margin: 0 auto;
}

.section-title {
  text-align: center;
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 40px;
  color: #333;
}

/* --- Features --- */
.features-section {
  background: #f5f5f5;
}

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

.feature-card {
  background: #fff;
  border-radius: 12px;
  padding: 32px 24px;
  text-align: center;
  border: 1px solid #ddd;
}

.feature-icon {
  font-size: 40px;
  margin-bottom: 16px;
}

.feature-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  color: #333;
}

.feature-desc {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
}

/* --- How to use --- */
.steps {
  display: flex;
  gap: 32px;
  justify-content: center;
}

.step {
  flex: 1;
  max-width: 260px;
  text-align: center;
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: #4a90d9;
  color: #fff;
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 16px;
}

.step-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  color: #333;
}

.step-desc {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
}

/* --- Platforms --- */
.platforms-section {
  background: #f5f5f5;
}

.platforms-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  max-width: 600px;
  margin: 0 auto;
}

.platform-card {
  background: #fff;
  border-radius: 12px;
  padding: 32px 24px;
  text-align: center;
  border: 1px solid #ddd;
}

.platform-icon {
  font-size: 40px;
  margin-bottom: 12px;
}

.platform-name {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 4px;
  color: #333;
}

.platform-desc {
  font-size: 14px;
  color: #666;
  margin-bottom: 16px;
}

.platform-cta {
  display: inline-block;
  padding: 10px 24px;
  font-size: 14px;
  font-weight: 600;
  color: #fff;
  background: #4a90d9;
  border-radius: 20px;
  text-decoration: none;
  transition: opacity 0.15s;
}

.platform-cta:hover {
  opacity: 0.9;
}

.platform-coming-soon {
  display: inline-block;
  padding: 10px 24px;
  font-size: 14px;
  font-weight: 600;
  color: #999;
  background: #eee;
  border-radius: 20px;
}

/* --- Footer --- */
.footer {
  text-align: center;
  padding: 32px 24px;
  border-top: 1px solid #ddd;
}

.footer-lang-btn {
  display: inline-block;
  padding: 8px 20px;
  font-size: 14px;
  font-weight: 500;
  color: #4a90d9;
  background: none;
  border: 1px solid #4a90d9;
  border-radius: 20px;
  cursor: pointer;
  margin-bottom: 12px;
  transition: background 0.15s, color 0.15s;
}

.footer-lang-btn:hover {
  background: #4a90d9;
  color: #fff;
}

.footer-privacy-link {
  display: block;
  font-size: 14px;
  color: #4a90d9;
  text-decoration: none;
  margin-bottom: 12px;
}

.footer-privacy-link:hover {
  text-decoration: underline;
}

.footer-copy {
  font-size: 13px;
  color: #999;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .hero {
    padding: 60px 20px 48px;
  }

  .hero-title {
    font-size: 36px;
  }

  .hero-subtitle {
    font-size: 17px;
  }

  .section {
    padding: 48px 20px;
  }

  .section-title {
    font-size: 24px;
    margin-bottom: 32px;
  }

  .features-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .steps {
    flex-direction: column;
    align-items: center;
    gap: 24px;
  }

  .step {
    max-width: 100%;
  }

  .platforms-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
}