/* Feature Hub Overlay - Full Screen Mode Selection */
.feature-hub-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: linear-gradient(135deg, #0f0c29, #302b63, #24243e);
  z-index: 9999; /* Topmost layer */
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s ease-in-out;
}

.feature-hub-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

/* Background Blobs (Replicated from Login) */
.hub-blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  z-index: -1; /* Behind content */
  opacity: 0.6;
  animation: floatHub 10s infinite ease-in-out;
}

.hub-blob-1 {
  top: -10%;
  left: -10%;
  width: 500px;
  height: 500px;
  background: #3a7bd5;
  animation-delay: 0s;
}
.hub-blob-2 {
  bottom: -10%;
  right: -10%;
  width: 400px;
  height: 400px;
  background: #00d2ff;
  animation-delay: -5s;
}
.hub-blob-3 {
  top: 40%;
  left: 60%;
  width: 300px;
  height: 300px;
  background: #8e2de2;
  animation-delay: -2s;
}

@keyframes floatHub {
  0% {
    transform: translate(0, 0) scale(1);
  }
  50% {
    transform: translate(30px, -50px) scale(1.1);
  }
  100% {
    transform: translate(0, 0) scale(1);
  }
}

/* Close Button */
.hub-close-btn {
  position: absolute;
  top: 24px;
  left: 24px;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: white;
  font-size: 1.2rem;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
}

.hub-close-btn:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: rotate(90deg);
}

/* Feature Cards Container */
.feature-cards-container {
  display: flex;
  flex-direction: column; /* Vertical stack for mobile */
  gap: 24px;
  width: 90%;
  max-width: 400px; /* Limit width */
  z-index: 10;
}

/* Feature Card Styling */
.feature-card {
  background: rgba(255, 255, 255, 0.05); /* Glass effect */
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 20px;
  padding: 24px;
  display: flex;
  align-items: center;
  gap: 20px;
  cursor: pointer;
  
  /* Remove arrow from tutorial.css conflict */
  position: relative;
}

.feature-card::after {
  content: none !important;
  display: none !important;

  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
  text-decoration: none;
  color: white;
}

.feature-card:hover {
  transform: translateY(-5px) scale(1.02);
  background: rgba(255, 255, 255, 0.1);
  box-shadow: 0 10px 30px rgba(0, 240, 255, 0.2); /* Cyan glow */
  border-color: rgba(0, 240, 255, 0.3);
}

.feature-icon {
  width: 60px;
  height: 60px;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.1),
    rgba(255, 255, 255, 0.05)
  );
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  color: #00d2ff;
}

.feature-info h3 {
  margin: 0 0 4px 0;
  font-size: 1.4rem;
  font-weight: 600;
}

.feature-info p {
  margin: 0;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.6);
}

/* Specific Colors for Cards */
.card-visualizer .feature-icon {
  color: #00d2ff;
}
.card-mindmap .feature-icon {
  color: #8e2de2;
}
.card-quiz .feature-icon {
  color: #ff6b6b;
}

/* Responsive Grid for Desktop */
@media (min-width: 768px) {
  .feature-cards-container {
    flex-direction: row;
    max-width: 1000px;
  }

  .feature-card {
    flex: 1;
    flex-direction: column;
    text-align: center;
    padding: 40px 20px;
    aspect-ratio: 1/1; /* Square cards */
    justify-content: center;
  }

  .feature-icon {
    width: 80px;
    height: 80px;
    font-size: 2.5rem;
    margin-bottom: 10px;
  }
}

/* Hamburger Menu Button Style (Header) */
.hamburger-menu-btn {
  background: none;
  border: none;
  color: white;
  font-size: 1.2rem;
  padding: 8px;
  cursor: pointer;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-right: 12px;
  transition: background 0.3s ease;
}

.hamburger-menu-btn:hover {
  background: rgba(255, 255, 255, 0.1);
}