/* General Styles */
body {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'SF Pro Text', 'Helvetica Neue', 'Helvetica', 'Arial', sans-serif;
  background: linear-gradient(135deg, #0d0d0d 0%, #1a1a1a 50%, #0d0d0d 100%);
  color: #f5f5f5;
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Index Page Styles */
.index {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  min-height: 100vh;
  text-align: center;
  position: relative;
  padding: 40px 20px;
}

/* Logo and Title Container */
.logo-title-container { margin-bottom: 30px; }
.logo-title-container img { width: 300px; height: auto; }
.logo-title-container h1 { font-size: 1.5em; margin: 10px 0; }

/* Button Container */
.button-container {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 15px;
  max-width: 650px;
  margin: 0 auto;
}
.button-container a { text-decoration: none; }

/* Button Styles */
button {
  background: rgba(60, 60, 60, 0.6);
  color: #f5f5f5;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 10px;
  padding: 8px 16px;
  cursor: pointer;
  font-size: 1em;
  font-weight: 500;
  line-height: 1;
  transition: all 0.3s ease;
  width: 100%;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}
button:hover {
  background: rgba(70, 70, 70, 0.8);
  border-color: rgba(255, 255, 255, 0.3);
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
}
button:active { transform: scale(0.98); }
button:disabled { opacity: 0.5; cursor: not-allowed; }

/* Navigation Buttons */
.back-to-index { position: fixed; top: 20px; left: 20px; z-index: 1000; }
.nav-buttons {
  position: fixed;
  top: 20px;
  left: 20px;
  z-index: 1000;
  display: flex;
  gap: 10px;
}
.back-button {
  width: 50px;
  height: 50px;
  border: none;
  cursor: pointer;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(40, 40, 40, 0.7) 0%, rgba(30, 30, 30, 0.7) 100%);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.12);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
  text-decoration: none;
}
.back-button svg {
  width: 24px;
  height: 24px;
  color: rgba(255, 255, 255, 0.7);
  transition: all 0.3s ease;
}
.back-button:hover {
  background: linear-gradient(135deg, rgba(50, 50, 50, 0.8) 0%, rgba(40, 40, 40, 0.8) 100%);
  border-color: rgba(255, 255, 255, 0.25);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
}
.back-button:hover svg {
  color: rgba(255, 255, 255, 0.95);
}

/* Quiz Layout */
.quiz-wrapper { width: 100%; max-width: 900px; margin: 0 auto; }
.quiz-container {
  background: linear-gradient(135deg, rgba(30, 30, 30, 0.95) 0%, rgba(25, 25, 25, 0.95) 100%);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 20px;
  padding: 36px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(255, 255, 255, 0.1);
  text-align: left;
  backdrop-filter: blur(30px);
}

.question { font-weight: bold; margin-bottom: 15px; font-size: 1.2em; }
.answers { margin-bottom: 20px; }
.answers label {
  display: block;
  padding: 16px;
  margin: 10px 0;
  background: linear-gradient(135deg, rgba(40, 40, 40, 0.3) 0%, rgba(35, 35, 35, 0.3) 100%);
  border-radius: 14px;
  cursor: pointer;
  transition: all 0.3s ease;
  border: 1px solid rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(10px);
}
.answers label:hover {
  background: linear-gradient(135deg, rgba(50, 50, 50, 0.4) 0%, rgba(45, 45, 45, 0.4) 100%);
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}
.answers input { margin-right: 10px; }

/* Navigation row */
.navigation {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 20px 0;
}

/* Question nav pills */
.question-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 15px 0 5px 0;
}
.question-nav-btn {
  min-width: 36px;
  height: 36px;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: linear-gradient(135deg, rgba(45, 45, 45, 0.7) 0%, rgba(35, 35, 35, 0.7) 100%);
  color: #f5f5f5;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}
.question-nav-btn:hover {
  background: linear-gradient(135deg, rgba(55, 55, 55, 0.8) 0%, rgba(45, 45, 45, 0.8) 100%);
  border-color: rgba(255, 255, 255, 0.25);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}
.flagged  { background-color: #5a3b00 !important; border: 1px solid #7a5300 !important; }
.answered { background-color: #1e4020 !important; border: 1px solid #2b5c2f !important; }
.current  { box-shadow: 0 0 0 2px #af0000 inset; transform: scale(1.06); }

/* Results & review */
#results, #review { margin-top: 20px; }
#grade { font-size: 1.4em; font-weight: bold; margin: 15px 0; }
.pass { color: #3cd67b; }
.fail { color: #ff6b6b; }

.review-item {
  margin-bottom: 20px;
  padding: 16px;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(45, 45, 45, 0.7) 0%, rgba(35, 35, 35, 0.7) 100%);
  border: 1px solid rgba(255, 255, 255, 0.12);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}
.review-answer { padding: 5px 8px; margin: 4px 0; border-radius: 6px; }
.user-correct { color: #3cd67b; font-weight: bold; }
.user-incorrect { color: #ff6b6b; text-decoration: line-through; }
.correct-answer { color: #3cd67b; font-weight: bold; }

.note { font-style: italic; color: #b0b0b0; font-size: 0.95em; }
.hidden { display: none; }