/* Reset and base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

/* Container */
.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
header {
  background: linear-gradient(to right, #3b74ff, #6d93ff);
  color: white;
  padding: 60px 0;
  text-align: center;
}

h1 {
  font-size: 48px;
  font-weight: 700;
  margin-bottom: 16px;
}

.subtitle {
  font-size: 20px;
  opacity: 0.9;
}

/* Layout */
main {
  padding: 40px 0;
}

h2 {
  font-size: 32px;
  margin-bottom: 20px;
}

p {
  margin-bottom: 20px;
}

/* Typography */
.note {
  background-color: #fff8e6;
  border-left: 4px solid #ffd700;
  padding: 16px;
  margin: 24px 0;
  border-radius: 0 4px 4px 0;
}

/* Components */
.section {
  margin-bottom: 48px;
  margin-top: 36px;
  opacity: 0;
  transform: translateY(10px);
  animation: fadeIn 0.6s ease-out forwards;
}

.section:nth-child(1) {
  animation-delay: 0.1s;
}

.section:nth-child(2) {
  animation-delay: 0.2s;
}

.section:nth-child(3) {
  animation-delay: 0.3s;
}

.section:nth-child(4) {
  animation-delay: 0.4s;
}

@keyframes fadeIn {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 999px;
  background-color: #f0f5ff;
  color: #3b74ff;
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 8px;
}

/* Course links */
.course-links {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.course-card {
  padding: 20px;
  border-radius: 8px;
  border: 1px solid #eaeaea;
  transition: all 0.2s;
}

.course-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  border-color: #3b74ff;
}

.course-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}

.course-card p {
  font-size: 14px;
  color: #666;
  margin-bottom: 16px;
}

.course-link {
  display: inline-flex;
  align-items: center;
  color: #3b74ff;
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
}

.course-link:hover {
  text-decoration: underline;
}

.course-link svg {
  width: 16px;
  height: 16px;
  margin-left: 4px;
}

/* Button styles */
.button {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background-color: #3b74ff;
  color: white;
  border: none;
  padding: 12px 24px;
  border-radius: 6px;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.2s;
}

.button:hover {
  background-color: #2861ff;
}

.button svg {
  width: 20px;
  height: 20px;
}

/* Video container */
.video-container {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  margin: 24px 0;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.video-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: none;
}

/* Footer */
footer {
  text-align: center;
  padding: 40px 0;
  color: #666;
  font-size: 14px;
}

/* Responsive styles */
@media (max-width: 640px) {
  h1 {
    font-size: 36px;
  }

  .subtitle {
    font-size: 18px;
  }

  h2 {
    font-size: 28px;
  }

  .course-links {
    grid-template-columns: 1fr;
  }
}