/* Root styles */
body {
  font-family: 'Segoe UI', sans-serif;
  margin: 0;
  padding: 0;
  background: #f0f4f8;
  color: #333;
}

/* Container */
.container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 20px;
}

/* Heading */
h1 {
  text-align: center;
  color: #2c3e50;
}

/* Subject & Chapter Buttons */
.subjects, .chapters {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 15px;
  margin-top: 30px;
}

.subject-btn, .chapter-btn, .mode-btn {
  padding: 15px;
  font-size: 16px;
  background: #3498db;
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.3s ease;
  text-align: center;
}

.subject-btn:hover, .chapter-btn:hover, .mode-btn:hover {
  background: #2980b9;
}

/* Quiz & Prepare MCQs */
.mcq-box {
  background: #fff;
  padding: 20px;
  margin: 20px auto;
  border-radius: 12px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  max-width: 700px;
  width: 100%;
}

/* Responsive Navbar Override */
@media (max-width: 768px) {
  .navbar {
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
  }

  .nav-btn, .logout-btn {
    padding: 10px 14px;
    font-size: 14px;
  }

  #user-greet {
    width: 100%;
    text-align: center;
    margin-bottom: 10px;
  }

  .subjects, .chapters {
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  }
}

/* Quiz options */
.option {
  padding: 12px;
  margin: 8px 0;
  background: #ecf0f1;
  border-radius: 6px;
  cursor: pointer;
}

/* Footer (optional) */
footer {
  text-align: center;
  margin: 40px 0 20px;
  color: #888;
  font-size: 14px;
}