.hero {
  padding: 8rem 0 6rem;
  background: var(--dark);
  color: white;
}

.hero-content {
  max-width: 700px;
}

.hero-label {
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  margin-bottom: 1rem;
}

.hero-title {
  font-size: clamp(2.25rem, 5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 1.5rem;
  font-family: "Poppins", "Space Grotesk", sans-serif;
}

.hero-desc {
  font-size: 1.15rem;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.75);
  margin-bottom: 2rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.btn-start {
  background: var(--primary);
  color: white !important;
  padding: 0.95rem 2rem;
  border-radius: 8px;
  font-weight: 700;
  text-decoration: none;
  font-size: 1rem;
  border: 2px solid var(--primary);
  transition: background 0.25s ease;
}

.btn-start:hover {
  background: var(--primary-dark);
  border-color: var(--primary-dark);
  color: white !important;
}

.btn-browse {
  color: white !important;
  padding: 0.95rem 1.75rem;
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  border: 2px solid white;
  border-radius: 8px;
  transition: background 0.25s ease;
}

.btn-browse:hover {
  background: white;
  color: var(--dark) !important;
}

.introduction {
  padding: 6rem 0;
  background: var(--bg);
}

.intro-content {
  max-width: 700px;
  margin: 0 auto;
  text-align: justify;
}

.intro-content p {
  font-size: 1.1rem;
  line-height: 1.8;
  margin-bottom: 1.25rem;
  color: var(--text-light);
}

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

.topics {
  padding: 6rem 0;
  background: var(--bg-alt);
  color: var(--text);
}

.topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.topic-card {
  background: var(--bg);
  padding: 2.5rem;
  border-radius: 12px;
  text-decoration: none;
  color: var(--text);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  border: 3px solid var(--border);
  position: relative;
  overflow: hidden;
  will-change: transform;
}

.topic-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--primary);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.topic-card:hover::before {
  transform: scaleX(1);
}

.topic-card:hover {
  border-color: var(--primary);
  transform: translateY(-4px);
}

.topic-card.disabled {
  opacity: 0.6;
  pointer-events: none;
}

.topic-card.disabled::before {
  display: none;
}

.topic-card h3 {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
  color: var(--text);
  font-weight: 700;
  font-family: "Space Grotesk", "Montserrat", sans-serif;
  transition: color 0.3s;
}

.topic-card:hover h3 {
  color: var(--primary);
}

.topic-card p {
  color: var(--text-light);
  margin-bottom: 1.5rem;
  font-size: 1rem;
  line-height: 1.6;
}

.badge {
  display: inline-block;
  padding: 0.5rem 1rem;
  background: var(--primary);
  color: white;
  border-radius: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge.soon {
  background: var(--text-light);
}

@media (max-width: 768px) {
  .hero {
    padding: 6rem 0 4rem;
  }

  .hero-actions {
    flex-direction: column;
  }

  .btn-start,
  .btn-browse {
    text-align: center;
  }

  .introduction,
  .topics {
    padding: 3rem 0;
  }

  .project-card {
    max-width: 100%;
  }

  .section-title {
    margin-bottom: 2rem;
  }

  .topics-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .topic-card {
    padding: 2rem;
  }

  .topic-card h3 {
    font-size: 1.35rem;
  }
}

@media (max-width: 480px) {
  .hero {
    padding: 5rem 0 3rem;
  }

  .introduction,
  .topics {
    padding: 2rem 0;
  }

  .topic-card {
    padding: 1.5rem;
  }

  .intro-content p {
    font-size: 1rem;
  }
}