/* \\wsl.localhost\Debian\home\tinytux\flashcards\Debian\home\tinytux\flashcards\style.css */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--bg-gradient);
    min-height: 100vh; /* Très important pour que le footer puisse aller en bas */
    display: flex;
    flex-direction: column; /* MODIFIÉ : Organise les enfants (container, footer) verticalement */
    align-items: center;   /* Centre .container et .footer horizontalement */
    padding: 20px 0;       /* Garde le padding vertical, horizontal géré par .container ou footer si besoin */
    /* justify-content: center; /* Supprimé ou changé pour flex-start si vous voulez le contenu en haut */
}

:root {
    --bg-gradient: linear-gradient(135deg, #1e3c72, #2a5298);
    --card-front: linear-gradient(135deg, #667eea, #764ba2);
    --card-back: linear-gradient(135deg, #f093fb, #f5576c);
    --btn-primary: linear-gradient(45deg, #ff6b6b, #ee5a24);
    --btn-secondary: linear-gradient(45deg, #4834d4, #686de0);
    --btn-success: linear-gradient(45deg, #00d2d3, #54a0ff);
}

.container {
    max-width: 800px;
    width: 100%;
}

.header {
    text-align: center;
    margin-bottom: 30px;
    color: white;
}

.header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.theme-selector {
    text-align: center;
    margin-bottom: 20px;
}

.theme-selector select {
    padding: 10px 20px;
    border: none;
    border-radius: 20px;
    font-size: 16px;
    background: rgba(255,255,255,0.9);
    color: #333;
    cursor: pointer;
    min-width: 200px;
}

.controls {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 25px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.btn-primary {
    background: var(--btn-primary);
    color: white;
    box-shadow: 0 4px 15px rgba(255, 107, 107, 0.4);
}

.btn-secondary {
    background: var(--btn-secondary);
    color: white;
    box-shadow: 0 4px 15px rgba(72, 52, 212, 0.4);
}

.btn-success {
    background: var(--btn-success);
    color: white;
    box-shadow: 0 4px 15px rgba(0, 210, 211, 0.4);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0,0,0,0.3);
}

.card-container {
    perspective: 1000px;
    height: 400px;
    margin-bottom: 30px;
}

.card {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.6s;
    cursor: pointer;
}

.card.flipped {
    transform: rotateY(180deg);
}

.card-face {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 30px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
}

.card-front {
    background: var(--card-front);
    color: white;
}

.card-back {
    background: var(--card-back);
    color: white;
    transform: rotateY(180deg);
}

.card-content {
    text-align: center;
    width: 100%;
    /* max-width: 100%; */
}

.card-content h2 {
    font-size: 1.8em;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.card-content p {
    font-size: 1.1em;
    line-height: 1.6;
    text-shadow: 1px 1px 2px rgba(0,0,0,0.3);
}

.card-content .formula {
    background: rgba(255,255,255,0.2);
    padding: 15px;
    border-radius: 10px;
    margin: 15px 0;
    font-family: 'Courier New', monospace;
    font-weight: bold;
}

.card-content .highlight {
    background: rgba(255,255,255,0.3);
    padding: 2px 8px;
    border-radius: 5px;
    font-weight: bold;
}

.progress {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
    color: white;
    font-size: 1.2em;
    margin-bottom: 20px;
}

.progress-bar {
    width: 45%;
    height: 10px;
    background: rgba(255,255,255,0.3);
    border-radius: 5px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--btn-success);
    transition: width 0.3s ease;
    border-radius: 5px;
}

.category-filter {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 8px 16px;
    border: 2px solid rgba(255,255,255,0.3);
    background: transparent;
    color: white;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-btn.active,
.filter-btn:hover {
    background: rgba(255,255,255,0.2);
    border-color: rgba(255,255,255,0.6);
}

.instructions {
    background: rgba(255,255,255,0.1);
    color: white;
    padding: 20px;
    border-radius: 15px;
    margin-bottom: 20px;
    text-align: center;
}

@media (max-width: 600px) {
    .header h1 {
        font-size: 2em;
    }
    
    .card-container {
        height: 375px;
    }
    
    .card-content h2 {
        font-size: 1.4em;
    }
    
    .card-content p {
        font-size: 0.9em;
    }
}
/* Styles pour la Navbar Années */
.year-navbar {
    text-align: center;
    margin-bottom: 20px;
    padding: 10px;
    background: rgba(0,0,0,0.1);
    border-radius: 10px;
}

.year-navbar .year-btn {
    padding: 8px 15px;
    margin: 0 5px;
    border: 1px solid rgba(255,255,255,0.5);
    background-color: transparent;
    color: white;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.year-navbar .year-btn:hover,
.year-navbar .year-btn.active {
    background-color: rgba(255,255,255,0.3);
    border-color: white;
}

/* Styles pour le Footer */
.footer {
    text-align: center;
    margin-top: 40px;
    padding: 20px;
    color: rgba(255,255,255,0.7);
    font-size: 0.9em;
}

.footer p {
    margin: 5px 0;
}

.footer a {
    color: rgba(255,255,255,0.9);
    text-decoration: none;
}
.footer a:hover {
    text-decoration: underline;
}

.theme-buttons-container {
    display: flex;
    flex-wrap: wrap; /* Permet aux boutons de passer à la ligne si pas assez de place */
    gap: 8px; /* Espace entre les boutons */
    margin-bottom: 20px; /* Espace sous le conteneur de boutons */
    justify-content: center; /* Centre les boutons s'ils n'occupent pas toute la largeur */
}

.theme-btn {
    padding: 8px 12px;
    border: 1px solid #ccc;
    background-color: #f8f9fa;
    color: #333;
    cursor: pointer;
    border-radius: 4px;
    font-size: 0.9em;
    transition: background-color 0.2s ease-in-out, color 0.2s ease-in-out;
}

.theme-btn:hover {
    background-color: #e9ecef;
}

.theme-btn.active {
    background-color: #007bff; /* Ou une autre couleur pour indiquer la sélection */
    color: white;
    border-color: #007bff;
}

.info-message { /* Style pour les messages comme "Aucun thème..." */
    color: #555;
    padding: 10px;
    width: 100%;
    text-align: center;
    font-style: italic;
}

.placeholder-button {
  display: block;
  /* width: 100%; */
  padding: 16px 24px;
  
  /* Couleurs et bordure */
  /* background-color: #f8f9fa; Un gris très clair */
  background-color: #a5e1ff; 
  border: 2px dashed #dee2e6; /* Une bordure en pointillés pour montrer que c'est une zone d'attente */
  color: #495057; /* Couleur du texte, bien lisible */

  /* Les coins arrondis ! */
  border-radius: 12px;

  /* Texte */
  text-align: center;
  font-size: 1.1em;
  font-weight: 500;
  
  /* Autres */
  cursor: default; /* Le curseur ne change pas au survol, car ce n'est pas un vrai bouton */
  box-sizing: border-box; /* Assure que le padding n'augmente pas la largeur totale */
  transition: all 0.2s ease-in-out; /* Petite transition douce pour le survol */
}

/* petit effet au survol pour le dynamisme */
.placeholder-button:hover {
    border-color: #adb5bd;
    background-color: #f1f3f5;
}