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

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: #3d3dbf;
  color: #000;
  min-height: 100vh;
}

/* Navbar */
.navbar {
  display: flex;
  align-items: center;
  padding: 8px 16px;
  background-color: #3d3dbf;
}

.navbar img {
  height: 50px;
  width: 50px;
  object-fit: contain;
}

.navbar a {
  display: flex;
  align-items: center;
  text-decoration: none;
}

/* Main */
main {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 40px 20px 60px;
}

main h1 {
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 700;
  color: #000;
  text-align: center;
  margin-bottom: 32px;
}

main h2 {
  font-size: clamp(1.1rem, 2vw, 1.4rem);
  font-weight: 700;
  color: #000;
  text-align: center;
  margin-bottom: 24px;
}

/* Banner */
.banner-wrapper {
  margin-bottom: 40px;
}

.banner-wrapper img {
  max-width: 480px;
  width: 100%;
  border-radius: 8px;
  display: block;
}

/* Cards */
.grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  background-color: #fff;
  border-radius: 16px;
  max-width: 1100px;
  width: 100%;
  overflow: hidden;
}

.card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 32px 24px;
  text-decoration: none;
  color: inherit;
  border-right: 1px solid #e5e5e5;
  transition: background-color 0.2s ease;
}

.card:last-child {
  border-right: none;
}

.card:hover {
  background-color: #f5f5ff;
}

.card h2 {
  font-size: 1.1rem;
  font-weight: 700;
  color: #3333cc;
  text-decoration: underline;
  margin-bottom: 12px;
}

.card p {
  font-size: 0.9rem;
  color: #3333cc;
  text-decoration: underline;
  line-height: 1.5;
}

/* Content Box */
.content-box {
  background-color: #fff;
  border-radius: 16px;
  max-width: 860px;
  width: 100%;
  padding: 40px;
  margin-bottom: 32px;
}

.content-box p {
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: 16px;
  color: #222;
}

.content-box p:last-child {
  margin-bottom: 0;
}

/* CTA Button */
.btn {
  display: inline-block;
  background-color: #3333cc;
  color: #fff;
  text-decoration: none;
  padding: 12px 28px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 1rem;
  margin: 8px;
  transition: background-color 0.2s ease;
}

.btn:hover {
  background-color: #2222aa;
}

.btn-outline {
  background-color: transparent;
  border: 2px solid #3333cc;
  color: #3333cc;
}

.btn-outline:hover {
  background-color: #3333cc;
  color: #fff;
}

.cta-group {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 24px;
}

/* Blog Cards */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
  max-width: 1100px;
  width: 100%;
}

.blog-card {
  background-color: #fff;
  border-radius: 12px;
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.blog-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.15);
}

.blog-card img {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.blog-card-body {
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.blog-card-body h3 {
  font-size: 1rem;
  font-weight: 700;
  color: #3333cc;
  margin-bottom: 8px;
  line-height: 1.4;
}

.blog-card-body .date {
  font-size: 0.8rem;
  color: #888;
  margin-bottom: 8px;
}

.blog-card-body p {
  font-size: 0.9rem;
  color: #444;
  line-height: 1.5;
  flex: 1;
}

.blog-card-body .read-more {
  margin-top: 12px;
  font-size: 0.85rem;
  color: #3333cc;
  font-weight: 600;
}

/* Video Grid */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
  max-width: 1100px;
  width: 100%;
}

.video-card {
  background-color: #fff;
  border-radius: 12px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.video-card iframe {
  width: 100%;
  aspect-ratio: 16/9;
  border: none;
}

.video-card-body {
  padding: 16px;
}

.video-card-body p {
  font-size: 0.9rem;
  color: #333;
  line-height: 1.5;
}

/* GitHub Repos */
.repo-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  max-width: 1100px;
  width: 100%;
}

.repo-card {
  background-color: #fff;
  border-radius: 12px;
  padding: 20px;
  text-decoration: none;
  color: inherit;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.repo-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(0,0,0,0.15);
}

.repo-card h3 {
  font-size: 1rem;
  color: #3333cc;
  font-weight: 700;
}

.repo-card p {
  font-size: 0.85rem;
  color: #555;
  line-height: 1.5;
  flex: 1;
}

.repo-meta {
  display: flex;
  gap: 12px;
  font-size: 0.8rem;
  color: #888;
}

.loading {
  color: #fff;
  font-size: 1rem;
  text-align: center;
  padding: 20px;
}

.error {
  color: #ffcccc;
  font-size: 0.9rem;
  text-align: center;
  padding: 20px;
}

/* Responsive */
@media (max-width: 768px) {
  .grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .card {
    border-right: 1px solid #e5e5e5;
    border-bottom: 1px solid #e5e5e5;
  }

  .card:nth-child(2n) {
    border-right: none;
  }

  .card:nth-last-child(-n+2) {
    border-bottom: none;
  }

  .content-box {
    padding: 24px;
  }
}

@media (max-width: 480px) {
  .grid {
    grid-template-columns: 1fr;
  }

  .card {
    border-right: none;
    border-bottom: 1px solid #e5e5e5;
  }

  .card:last-child {
    border-bottom: none;
  }
}