/* === General Layout === */
/* Base page layout: center quiz card and set background gradient */
body {
  font-family: 'Inter', Arial, sans-serif;
  background: linear-gradient(135deg, #c7d2e9 0%, #c5e6f0 100%);
  color: #222;
  display: flex;               /* center content with Flexbox */
  justify-content: center;
  align-items: center;
  min-height: 100vh;          /* full viewport height */
  margin: 0;                  /* remove default page margin */
}

/* === Quiz Container === */
/* Card that holds the entire quiz */
#quiz-container {
  background: #ffffff;
  padding: 2rem 2.5rem;
  border-radius: 20px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
  width: 100%;
  max-width: 480px;           /* limit card width for readability */
  text-align: center;
  display: flex;              /* use Flexbox for vertical layout */
  flex-direction: column;
  gap: 1.5rem;                /* vertical spacing between children */
  animation: fadeIn 0.5s ease-in; /* entrance animation */
}

#quiz-logo {
  width: 140px;
  height: auto;
  margin: 0 auto 1rem;
  display: block;
  border-radius: 12px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

/* === Title === */
/* Styling for the main title inside the card */
#quiz-container h1 {
  font-size: 1.8rem;
  color: #0a0a0a;
  margin-bottom: 0.5rem;
}

/* === Quiz Selection Buttons === */
/* Buttons that choose which quiz to start */
.quiz-btn {
  background: #0078ff;
  color: #fff;
  border: none;
  border-radius: 10px;
  padding: 0.9rem 1.2rem;
  margin-top: 1.5rem;
  font-size: 1.5rem;
  width: 80%;                 /* make selection buttons not full-width */
  cursor: pointer;
  transition: background 0.2s ease, transform 0.1s ease;
}

#instructions {
  font-size: 0.95rem;
  color: #333;
  background: #f9f9f9;
  border-radius: 10px;
  padding: 1rem;
  margin-bottom: 1rem;
  line-height: 1.4;
}

/* Hover state: slight lift and darker background */
.quiz-btn:hover {
  background: #005fe0;
  transform: translateY(-2px);
}

/* === Question and Options === */
/* Question text styling */
#question {
  font-weight: 600;
  font-size: 1.1rem;
  margin-bottom: 1rem;
}

/* Options list uses column layout with even gaps */
#options {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

/* Individual option button styling */
#options button {
  background: #f4f4f4;
  border: 2px solid #ddd;
  border-radius: 10px;
  padding: 0.8rem;
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

/* Hover on options to give feedback */
#options button:hover {
  background: #e9f1ff;
  border-color: #0078ff;
}

/* Styles applied when answer is correct */
.correct {
  background-color: #28a745 !important; /* green */
  color: #fff !important;
  border: none !important;
}

/* Styles applied when answer is wrong */
.wrong {
  background-color: #dc3545 !important; /* red */
  color: #fff !important;
  border: none !important;
}

/* === Next and Restart Buttons === */
/* Shared styles for next/restart controls */
#next-btn,
#restart-btn {
  background: #058637;        /* green tone for action */
  color: #fff;
  border: none;
  border-radius: 10px;
  padding: 0.9rem 1.2rem;
  font-size: 1rem;
  cursor: pointer;
  margin-top: 1.5rem;
  align-self: center;         /* center inside the flex column */
  min-width: 120px;
}

/* Hover state for action buttons (keeps same hue but could darken) */
#next-btn:hover,
#restart-btn:hover {
  background: #04672a;        /* slightly darker for hover */
}

/* === Results === */
/* Default hidden; revealed by JS by removing the 'hidden' class or setting inline display */
#result-container {
  display: none;              /* keep hidden on initial load to avoid flash */
  flex-direction: column;
  align-items: center;
  gap: 0.8rem;
}

/* Result headline */
#result-message {
  font-size: 1.4rem;
  font-weight: 700;
  color: #0055ff;
}

/* Final score text */
#final-score {
  font-size: 1rem;
  color: #333;
}

/* === Utility === */
/* Reusable hidden class used by JS to toggle visibility */
.hidden {
  display: none;
}

/* Entrance animation used by the quiz card */
@keyframes fadeIn {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

/* === Accessibility === */
/* Strong visible focus ring for keyboard users */
button:focus {
  outline: 3px solid #0055ff;
  outline-offset: 2px;
}