/* Premium Glassmorphism Design for Audio Trainer */
:root {
    --primary: #8b5cf6;
    --primary-hover: #7c3aed;
    --bg-color: #f8fafc;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(255, 255, 255, 0.5);
    --glass-shadow: 0 8px 32px rgba(31, 38, 135, 0.07);
}

html.dark :root, body.theme-dark {
    --bg-color: #0f172a;
    --text-main: #f8fafc;
    --text-muted: #cbd5e1;
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

body {
    font-family: 'Inter', 'Roboto', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    margin: 0;
    padding: 0;
    transition: background-color 0.3s, color 0.3s;
    background-image: radial-gradient(circle at top right, rgba(139, 92, 246, 0.15), transparent 40%),
                      radial-gradient(circle at bottom left, rgba(56, 189, 248, 0.15), transparent 40%);
    background-attachment: fixed;
}

.audio-trainer-container {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.at-header {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 30px;
    padding-top: max(20px, env(safe-area-inset-top));
}

.at-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0;
    background: linear-gradient(135deg, var(--primary), #38bdf8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.back-btn {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-main);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    backdrop-filter: blur(10px);
    transition: transform 0.2s, background 0.2s;
}

.back-btn:hover {
    transform: scale(1.05);
    background: var(--primary);
    color: white;
}

.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: 24px;
    box-shadow: var(--glass-shadow);
    margin-bottom: 20px;
    animation: fadeInUp 0.5s ease-out;
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

h2 {
    font-size: 1.25rem;
    margin-top: 0;
    margin-bottom: 20px;
}

.setting-group {
    margin-bottom: 20px;
}

.setting-group h3 {
    font-size: 1rem;
    color: var(--text-muted);
    margin-bottom: 10px;
    font-weight: 600;
}

/* Custom Checkboxes */
.checkbox-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 10px;
}

label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-size: 0.95rem;
}

/* Range Slider */
.range-slider {
    display: flex;
    align-items: center;
    gap: 15px;
}

input[type="range"] {
    flex: 1;
    accent-color: var(--primary);
}

select {
    width: 100%;
    padding: 12px;
    border-radius: 12px;
    border: 1px solid var(--glass-border);
    background: var(--bg-color);
    color: var(--text-main);
    font-size: 1rem;
    outline: none;
    cursor: pointer;
}

.btn-primary {
    width: 100%;
    padding: 16px;
    background: linear-gradient(135deg, var(--primary), #6366f1);
    color: white;
    border: none;
    border-radius: 16px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    margin-top: 10px;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(139, 92, 246, 0.3);
}

/* Player View */
.player-info {
    text-align: center;
    margin-bottom: 10px;
    min-height: 120px;
}

#current-word {
    font-size: 2.2rem;
    font-weight: 800;
    margin: 0 0 10px;
}

#current-translation {
    font-size: 1.25rem;
    color: var(--primary);
    font-weight: 600;
    margin: 0 0 15px;
}

.sub-text {
    color: var(--text-muted);
    font-size: 1rem;
    line-height: 1.5;
}

.player-controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
    margin-bottom: 30px;
}

.control-btn {
    background: none;
    border: none;
    color: var(--text-main);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.2s, color 0.2s;
}

.control-btn:hover {
    transform: scale(1.1);
    color: var(--primary);
}

.play-pause-btn {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), #6366f1);
    color: white;
    box-shadow: 0 10px 25px rgba(139, 92, 246, 0.4);
}

.play-pause-btn:hover {
    color: white;
    transform: scale(1.05);
}

.player-actions {
    display: flex;
    gap: 10px;
}

.action-btn {
    flex: 1;
    padding: 12px;
    border-radius: 12px;
    border: 1px solid var(--glass-border);
    background: var(--glass-bg);
    color: var(--text-main);
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}

.action-btn:hover {
    background: rgba(139, 92, 246, 0.1);
    border-color: var(--primary);
}
/* --- Exam Styles --- */
.exam-card {
    min-height: 400px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.exam-options-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 10px;
    margin-top: 20px;
}

.exam-option-btn {
    padding: 15px;
    border-radius: 12px;
    border: 1px solid var(--glass-border);
    background: var(--glass-bg);
    color: var(--text-main);
    font-size: 1.1rem;
    cursor: pointer;
    transition: background 0.2s, transform 0.1s;
}

.exam-option-btn:hover {
    background: rgba(139, 92, 246, 0.15);
    transform: scale(1.02);
}

.exam-option-btn:disabled {
    cursor: not-allowed;
    opacity: 0.8;
}

.puzzle-drop-area {
    min-height: 60px;
    border: 2px dashed var(--glass-border);
    border-radius: 12px;
    padding: 10px;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 20px;
    background: rgba(0, 0, 0, 0.05);
}

.puzzle-pieces-area {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    min-height: 100px;
}

.puzzle-piece {
    padding: 10px 15px;
    background: var(--primary);
    color: white;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    user-select: none;
    transition: transform 0.1s;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.puzzle-piece:active {
    transform: scale(0.95);
}

.puzzle-piece.correct {
    background: #10b981;
}