/* ATTENTION : une petite partie des style est dans le HTML */

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box; }

body {
  font-family: 'Poppins', sans-serif;
  background-color: #f5f7fa;
  color: var(--dark);
  line-height: 1.6; }

header {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: white;
  text-align: center;
  padding: 2rem 1rem;
  box-shadow: var(--box-shadow); }

h1 {
  font-size: 2rem;
  margin-bottom: 0.5rem; }

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem; }

.theme-selector {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin: 2rem 0;
  flex-wrap: wrap; }

.theme-btn {
  background: white;
  color: var(--dark);
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: var(--border-radius);
  cursor: pointer;
  font-weight: 600;
  transition: var(--transition);
  box-shadow: var(--box-shadow); }

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

.theme-btn:hover:not(.active) {
  background: #f1f1f1; }



.flashcard {
  background: white;
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--box-shadow);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  height: 333px;
  transform: translateZ(0); }

.flashcard:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1); }

.flashcard-header {
  background: var(--primary);
  color: white;
  padding: 1rem;
  text-align: center;
  font-weight: 600; }

.flashcard-content {
  padding: 1.5rem;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative; }

.flashcard-front, .flashcard-back {
  backface-visibility: hidden;
  transition: var(--transition);
  position: absolute;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 1.5rem;
  box-sizing: border-box; }

.flashcard-back {
  transform: rotateY(180deg);
  background: white; }

.flashcard-inner {
  position: relative;
  width: 100%;
  height: 100%;
  text-align: center;
  transition: var(--transition);
  transform-style: preserve-3d; }

.flashcard.flipped .flashcard-inner {
  transform: rotateY(180deg); }

.question {
  font-size: 1.1rem;
  margin-bottom: 1rem;
  font-weight: 500; }

.answer {
  font-size: 1rem;
  color: var(--secondary);
  font-weight: 400; }

.flashcard-footer {
  display: flex;
  justify-content: center;
  padding: 1rem;
  background: var(--light);
  border-top: 1px solid #eee;
  margin-top: auto; }

.flip-btn {
  background: var(--accent);
  color: white;
  border: none;
  padding: 0.5rem 1rem;
  border-radius: 5px;
  cursor: pointer;
  font-weight: 600;
  transition: var(--transition); }

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

footer {
  text-align: center;
  padding: 1.5rem;
  background: var(--dark);
  color: white;
  margin-top: 2rem; }


.theme-title {
  grid-column: 1 / -1;
  text-align: center;
  margin: 1rem 0;
  font-size: 1.5rem;
  color: var(--secondary); }

template {
  display: none; }