/* ==============  GLOBAL STYLES  ============== */
:root {
  --color-primary: #28a745;   /* Energize & Empower green */
  --color-secondary: #fd7e14; /* Accent orange */
  --color-accent: #ffc107;    /* Highlight yellow */
  --color-dark: #2c3e50;      /* Dark text */
  --color-light: #f8f9fa;     /* Light background */
  --color-border: #dee2e6;    /* Light border */
  --radius: 8px;
  --shadow: 0 2px 6px rgba(0,0,0,0.06);
  --transition: all 0.25s ease-in-out;
  --font-main: "Segoe UI", Arial, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  font-family: var(--font-main);
  color: var(--color-dark);
  background: var(--color-light);
}

/* ==============  LAYOUT  ============== */
.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem;
}

.section {
  display: none;
}

.section.active {
  display: block;
}

/* ==============  HEADER / NAV  ============== */
header {
  background: var(--color-primary);
  color: #fff;
  padding: 1rem 0;
  box-shadow: var(--shadow);
}

header h1 {
  margin: 0;
  font-size: 1.6rem;
  text-align: center;
}

/* ==============  BUTTONS  ============== */
.btn {
  display: inline-block;
  padding: 0.6rem 1.25rem;
  border: none;
  border-radius: var(--radius);
  background: var(--color-primary);
  color: #fff;
  font-size: 1rem;
  cursor: pointer;
  transition: var(--transition);
}

.btn:hover,
.btn:focus {
  background: #20903a;
}

.btn-secondary {
  background: var(--color-secondary);
}

.btn-secondary:hover,
.btn-secondary:focus {
  background: #e36b05;
}

/* ==============  QUIZ MODULE  ============== */
.quiz-wrapper {
  margin-top: 2rem;
}

.quiz-container {
  background: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 2rem 1.5rem;
  box-shadow: var(--shadow);
}

.question-text {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--color-dark);
  margin-bottom: 1.2rem;
}

.answer-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.answer-option {
  background: var(--color-light);
  border: 2px solid var(--color-border);
  color: var(--color-dark);
  padding: 0.75rem 1rem;
  margin-bottom: 0.9rem;
  border-radius: var(--radius);
  cursor: pointer;
  transition: var(--transition);
}

.answer-option:hover {
  background: #e9ecef;
  border-color: var(--color-primary);
}

.answer-option.selected {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

.answer-option.correct {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

.answer-option.incorrect {
  background: #dc3545;
  color: #fff;
  border-color: #dc3545;
}

/* ==============  FLASHCARDS  ============== */
.flashcard-container {
  margin-top: 2.5rem;
}

.flashcard {
  position: relative;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 2rem 1.5rem;
  text-align: center;
  cursor: pointer;
  min-height: 160px;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.flashcard:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 16px rgba(0,0,0,0.08);
}

.flashcard .front,
.flashcard .back {
  font-size: 1.1rem;
  font-weight: 500;
}

.flashcard .back {
  display: none;
}

.flashcard.flipped .front {
  display: none;
}

.flashcard.flipped .back {
  display: block;
}

/* ==============  PROGRESS & ANALYTICS  ============== */
.progress-wrapper {
  margin-top: 3rem;
}

.progress-bar-container {
  background: var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  height: 18px;
  margin-top: 0.5rem;
}

.progress-bar {
  height: 100%;
  width: 0;
  background: var(--color-primary);
  transition: width 0.6s ease;
}

.domain-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.25rem 1rem;
  margin-bottom: 1.1rem;
  box-shadow: var(--shadow);
}

.domain-card h4 {
  margin: 0 0 0.4rem 0;
  font-size: 1.05rem;
}

/* ==============  ACHIEVEMENTS  ============== */
.achievement-badge {
  display: inline-block;
  background: var(--color-accent);
  color: #212529;
  border-radius: 50%;
  width: 80px;
  height: 80px;
  line-height: 80px;
  margin: 0.4rem;
  font-weight: 700;
  box-shadow: var(--shadow);
}

/* ==============  PREMIUM PROMPTS  ============== */
.premium-prompt {
  background: var(--color-secondary);
  color: #fff;
  padding: 1.25rem;
  border-radius: var(--radius);
  margin-top: 2rem;
  text-align: center;
}

.premium-prompt a {
  color: #fff;
  text-decoration: underline;
  font-weight: 600;
}

.premium-prompt a:hover {
  color: #ffe1c4;
}

/* ==============  FOOTER  ============== */
footer {
  margin-top: 3rem;
  background: var(--color-dark);
  color: #fff;
  text-align: center;
  padding: 1.25rem 0;
  font-size: 0.9rem;
}

footer a {
  color: var(--color-accent);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}

/* ==============  RESPONSIVE BREAKPOINTS  ============== */
@media (max-width: 768px) {
  .question-text {
    font-size: 1.05rem;
  }
  .flashcard {
    padding: 1.5rem 1.2rem;
  }
}