/* ═══════════════════════════════════════════════════════════════════════════
   FLASHCARDS STYLES
   ═══════════════════════════════════════════════════════════════════════════ */

.flashcards-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-xl);
}

.flashcards-header h1 {
    font-size: 1.75rem;
}

/* Topic Filter */
.topic-filter {
    display: flex;
    gap: var(--space-sm);
    flex-wrap: wrap;
}

.filter-btn {
    padding: var(--space-sm) var(--space-md);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition);
}

.filter-btn:hover {
    border-color: var(--accent-blue);
    color: var(--text-primary);
}

.filter-btn.active {
    background: var(--accent-blue);
    border-color: var(--accent-blue);
    color: white;
}

/* Session Info */
.session-info {
    display: flex;
    justify-content: center;
    gap: var(--space-xl);
    padding: var(--space-lg);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-xl);
}

.session-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
}

.session-stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-green);
}

.session-stat-label {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Flashcard Container */
.flashcard-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xl);
    padding: var(--space-xl) 0;
}

/* 3D Flip Card */
.flashcard-wrapper {
    perspective: 1000px;
    width: 100%;
    max-width: 600px;
    height: 350px;
}

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

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

.flashcard-face {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    flex-direction: column;
    border-radius: var(--radius-xl);
    overflow: hidden;
}

.flashcard-front {
    background: linear-gradient(135deg, var(--bg-card) 0%, rgba(59, 130, 246, 0.1) 100%);
    border: 2px solid var(--accent-blue);
}

.flashcard-back {
    background: linear-gradient(135deg, var(--bg-card) 0%, rgba(34, 197, 94, 0.1) 100%);
    border: 2px solid var(--accent-green);
    transform: rotateY(180deg);
}

/* Card Header */
.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-md) var(--space-lg);
    border-bottom: 1px solid var(--border-color);
}

.card-topic {
    font-size: 0.875rem;
    color: var(--accent-blue);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.card-difficulty {
    display: flex;
    gap: 4px;
}

.difficulty-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--bg-secondary);
}

.difficulty-dot.active {
    background: var(--accent-yellow);
}

/* Card Content */
.card-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: var(--space-xl);
    text-align: center;
}

.card-question {
    font-size: 1.25rem;
    line-height: 1.6;
    color: var(--text-primary);
}

.card-answer {
    font-size: 1.1rem;
    line-height: 1.6;
    color: var(--text-primary);
}

.card-answer code {
    display: block;
    margin-top: var(--space-md);
    padding: var(--space-md);
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    font-family: 'Fira Code', monospace;
    font-size: 0.9rem;
    text-align: left;
    overflow-x: auto;
}

/* Card Footer */
.card-footer {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: var(--space-md);
    border-top: 1px solid var(--border-color);
}

.flip-hint {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.flip-hint svg {
    width: 16px;
    height: 16px;
    vertical-align: middle;
    margin-right: var(--space-xs);
}

/* Rating Buttons */
.rating-container {
    width: 100%;
    max-width: 600px;
}

.rating-label {
    text-align: center;
    margin-bottom: var(--space-md);
    font-weight: 500;
    color: var(--text-secondary);
}

.rating-buttons {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: var(--space-sm);
}

.rating-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-md);
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition);
}

.rating-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.rating-btn .rating-score {
    font-size: 1.5rem;
    font-weight: 700;
}

.rating-btn[data-rating="0"] { border-color: #ef4444; }
.rating-btn[data-rating="0"]:hover { background: rgba(239, 68, 68, 0.2); }
.rating-btn[data-rating="0"] .rating-score { color: #ef4444; }

.rating-btn[data-rating="1"] { border-color: #f97316; }
.rating-btn[data-rating="1"]:hover { background: rgba(249, 115, 22, 0.2); }
.rating-btn[data-rating="1"] .rating-score { color: #f97316; }

.rating-btn[data-rating="2"] { border-color: #eab308; }
.rating-btn[data-rating="2"]:hover { background: rgba(234, 179, 8, 0.2); }
.rating-btn[data-rating="2"] .rating-score { color: #eab308; }

.rating-btn[data-rating="3"] { border-color: #84cc16; }
.rating-btn[data-rating="3"]:hover { background: rgba(132, 204, 22, 0.2); }
.rating-btn[data-rating="3"] .rating-score { color: #84cc16; }

.rating-btn[data-rating="4"] { border-color: #22c55e; }
.rating-btn[data-rating="4"]:hover { background: rgba(34, 197, 94, 0.2); }
.rating-btn[data-rating="4"] .rating-score { color: #22c55e; }

.rating-btn[data-rating="5"] { border-color: #06b6d4; }
.rating-btn[data-rating="5"]:hover { background: rgba(6, 182, 212, 0.2); }
.rating-btn[data-rating="5"] .rating-score { color: #06b6d4; }

/* Progress Bar */
.progress-container {
    width: 100%;
    max-width: 600px;
    margin-top: var(--space-xl);
}

.progress-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: var(--space-sm);
    font-size: 0.875rem;
    color: var(--text-muted);
}

.progress-bar {
    height: 8px;
    background: var(--bg-secondary);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--gradient-xp);
    border-radius: var(--radius-full);
    transition: width 0.3s ease;
}

/* Navigation Buttons */
.card-navigation {
    display: flex;
    gap: var(--space-md);
    margin-top: var(--space-lg);
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-lg);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition);
}

.nav-btn:hover {
    background: var(--bg-card);
    border-color: var(--accent-blue);
    color: var(--text-primary);
}

.nav-btn svg {
    width: 16px;
    height: 16px;
}

/* Session Complete */
.session-complete {
    display: none;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xl);
    padding: var(--space-xxl);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    text-align: center;
    max-width: 500px;
    margin: 0 auto;
}

.session-complete.visible {
    display: flex;
}

.complete-icon {
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--accent-green), #16a34a);
    border-radius: 50%;
    color: white;
}

.complete-icon svg {
    width: 40px;
    height: 40px;
}

.complete-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.complete-stats {
    display: flex;
    gap: var(--space-xl);
}

.complete-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.complete-stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-green);
}

.complete-stat-label {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.complete-actions {
    display: flex;
    gap: var(--space-md);
}

/* No Cards State */
.no-cards {
    display: none;
    flex-direction: column;
    align-items: center;
    gap: var(--space-lg);
    padding: var(--space-xxl);
    text-align: center;
}

.no-cards.visible {
    display: flex;
}

.no-cards-icon {
    font-size: 4rem;
    opacity: 0.5;
}

.no-cards-text {
    color: var(--text-muted);
    font-size: 1.1rem;
}

/* ═══════════════════════════════════════════════════════════════════════════
   RESPONSIVE
   ═══════════════════════════════════════════════════════════════════════════ */

@media (max-width: 768px) {
    .flashcards-header {
        flex-direction: column;
        gap: var(--space-md);
    }

    .topic-filter {
        justify-content: center;
    }

    .session-info {
        flex-wrap: wrap;
        gap: var(--space-md);
    }

    .flashcard-wrapper {
        height: 300px;
    }

    .card-question,
    .card-answer {
        font-size: 1rem;
    }

    .rating-buttons {
        grid-template-columns: repeat(3, 1fr);
    }

    .rating-btn {
        padding: var(--space-sm);
    }

    .complete-stats {
        flex-wrap: wrap;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .flashcard-wrapper {
        height: 280px;
    }

    .rating-buttons {
        grid-template-columns: repeat(2, 1fr);
    }
}