:root {
    --primary-color: #007aff;
    --primary-hover: #0056b3;
    --background-color: #f3f3f3;
    --card-background: #f8f8f8;
    --card-background-active: #ffffff;
    --text-color: #2c3e50;
    --light-text: #888;
    --border-color: #e0e0e0;
    --red: #e74c3c;
    --green: #2ecc71;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 2rem;
}

.container {
    width: 100%;
    max-width: 1000px;
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

header h1 {
    font-weight: 700;
    font-size: 2rem;
    margin: 0;
}

/* Container für Aktionen und Formular */
.io-container,
.form-container,
.lern-modus-container {
    padding: 2rem;
    margin-bottom: 2.5rem;
}

h2 {
    font-size: 1.5rem;
    margin-top: 0;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

/* Buttons */
button {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 500;
    font-size: 1rem;
    transition: transform 0.2s ease, background-color 0.2s ease;
}

button:hover {
    transform: translateY(-2px);
}

.io-buttons {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1rem;
}

textarea {
    width: 100%;
    padding: 12px;
    margin-bottom: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
    box-sizing: border-box;
    transition: border-color 0.2s;
}

textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Grid für die Karten */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
}

.card-container {
    background-color: var(--card-background);
    display: flex;
    flex-direction: column;
    transition: transform 0.2s ease;
    position: relative;
    /* Für das Level-Badge */
}

.card-container:hover {
    transform: translateY(-5px);
}

/* Level Badge */
.level-badge {
    position: absolute;
    top: 10px;
    left: 10px;
    background-color: var(--primary-color);
    color: white;
    padding: 4px 8px;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 700;
    z-index: 10;
}

/* Flashcard */
.flashcard {
    height: 220px;
    perspective: 1000px;
    cursor: pointer;
}

.flashcard-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform 0.7s;
    transform-style: preserve-3d;
}

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

.flashcard-front,
.flashcard-back {
    position: absolute;
    width: 100%;
    height: 100%;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
    box-sizing: border-box;
    text-align: center;
    font-size: 1.1rem;
    border-radius: var(--border-radius) var(--border-radius) 0 0;
}

.flashcard-front {
    font-weight: 500;
}

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

/* Aktionen (Icons) */
.card-actions {
    display: flex;
    justify-content: flex-end;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    border-top: 1px solid var(--border-color);
}

.action-btn {
    background: none;
    border: none;
    font-size: 1.2rem;
    color: var(--text-color);
    padding: 8px;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    transition: background-color 0.2s, color 0.2s;
}

.action-btn:hover {
    transform: scale(1.1);
}

.btn-save {
    margin-top: 0.5rem;
}

.edit-form {
    display: none;
    padding: 1.5rem;
}

/* --- Lernmodus Stile --- */
.lern-modus-container {
    text-align: center;
}

#lern-karte {
    margin: 2rem auto;
    max-width: 600px;
    border-radius: var(--border-radius);
}

#lern-karte .flashcard-front,
#lern-karte .flashcard-back {
    border-radius: var(--border-radius);
    /* Stellt sicher, dass die inneren Seiten auch abgerundet sind */
}

.antwort-buttons {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin: 2rem 0;
}

.antwort-buttons button {
    padding: 15px 30px;
    font-size: 1.1rem;
}

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

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

.btn-rot:hover {
    background-color: #c0392b;
}

.btn-gruen:hover {
    background-color: #27ae60;
}

#lernmodus-beenden-btn {
    background-color: #7f8c8d;
    margin-top: 1rem;
}

#lernmodus-beenden-btn:hover {
    background-color: #6c7a7b;
}

/* Fortschrittsbalken */
#fortschritt-container {
    margin-bottom: 2rem;
}

#fortschritt-text {
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.fortschritt-balken-aussen {
    width: 100%;
    height: 20px;
    background-color: #e0e0e0;
    border-radius: 10px;
    overflow: hidden;
}

#fortschritt-balken-innen {
    height: 100%;
    width: 0%;
    background-color: var(--green);
    border-radius: 10px;
    transition: width 0.3s ease-in-out;
}