/* CSS Variables for theming */
:root {
    --color-bg: #1a1a2e;
    --color-card: #16213e;
    --color-primary: #e94560;
    --color-secondary: #0f3460;
    --color-text: #eaeaea;
    --color-success: #4caf50;
    --color-error: #f44336;
    --color-warning: #ff9800;
    --color-muted: #666;

    --font-main: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --border-radius: 12px;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

/* Reset and Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-main);
    background: var(--color-bg);
    color: var(--color-text);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

/* App Container */
.app-container {
    width: 100%;
    max-width: 500px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* Browser Warning */
.browser-warning {
    background: var(--color-error);
    color: white;
    padding: 15px;
    border-radius: var(--border-radius);
    text-align: center;
    font-weight: bold;
}

/* Header */
.app-header {
    text-align: center;
}

.app-header h1 {
    font-size: 1.5rem;
    font-weight: 600;
}

/* Timeout Control */
.timeout-control {
    background: var(--color-card);
    padding: 15px 20px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 15px;
    flex-wrap: wrap;
}

.timeout-control label {
    flex: 0 0 auto;
    font-size: 0.9rem;
}

.timeout-control input[type="range"] {
    flex: 1;
    min-width: 150px;
    cursor: pointer;
}

.timeout-control input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--color-primary);
    cursor: pointer;
}

.timeout-control input[type="range"]::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--color-primary);
    cursor: pointer;
    border: none;
}

#timeout-value {
    flex: 0 0 auto;
    font-weight: bold;
    color: var(--color-primary);
    min-width: 80px;
    text-align: right;
}

.checkbox-label {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin-left: 2rem;
    cursor: pointer;
    font-size: 0.9rem;
}

.checkbox-label input[type="checkbox"] {
    cursor: pointer;
    width: 16px;
    height: 16px;
}

/* Stats Bar */
.stats-bar {
    display: flex;
    justify-content: space-around;
    gap: 10px;
}

.stat {
    text-align: center;
    padding: 10px 20px;
    border-radius: var(--border-radius);
    background: var(--color-card);
    flex: 1;
}

.stat-label {
    display: block;
    font-size: 0.75rem;
    text-transform: uppercase;
    opacity: 0.7;
    margin-bottom: 5px;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: bold;
}

.stat.correct .stat-value { color: var(--color-success); }
.stat.incorrect .stat-value { color: var(--color-error); }
.stat.timeout .stat-value { color: var(--color-warning); }

/* Flashcard */
.flashcard {
    background: var(--color-card);
    border-radius: var(--border-radius);
    padding: 40px 30px;
    box-shadow: var(--shadow);
    text-align: center;
    position: relative;
}

/* Progress Bar */
.progress-container {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--color-secondary);
    border-radius: var(--border-radius) var(--border-radius) 0 0;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: var(--color-primary);
    width: 0%;
    transition: width 0.1s linear;
}

/* Letter Display */
.letter-display {
    font-size: 8rem;
    font-weight: bold;
    line-height: 1;
    margin: 20px 0;
    transition: color 0.3s, transform 0.3s;
}

.letter-display.correct {
    color: var(--color-success);
    transform: scale(1.1);
}

.letter-display.incorrect {
    color: var(--color-error);
    animation: shake 0.5s;
}

.letter-display.timeout {
    color: var(--color-warning);
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    20%, 60% { transform: translateX(-10px); }
    40%, 80% { transform: translateX(10px); }
}

/* Status Indicator */
.status-indicator {
    font-size: 1rem;
    padding: 10px 20px;
    border-radius: 20px;
    display: inline-block;
    margin: 15px 0;
}

.status-indicator.ready {
    background: var(--color-secondary);
}

.status-indicator.listening {
    background: var(--color-primary);
    animation: pulse 1.5s infinite;
}

.status-indicator.processing {
    background: var(--color-warning);
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.6; }
}

/* Feedback Container */
.feedback-container {
    margin-top: 20px;
    padding: 15px;
    border-radius: var(--border-radius);
}

.feedback-container.correct {
    background: rgba(76, 175, 80, 0.2);
    border: 2px solid var(--color-success);
}

.feedback-container.incorrect {
    background: rgba(244, 67, 54, 0.2);
    border: 2px solid var(--color-error);
}

.feedback-container.timeout {
    background: rgba(255, 152, 0, 0.2);
    border: 2px solid var(--color-warning);
}

.feedback-text {
    font-size: 1.2rem;
    font-weight: bold;
    margin-bottom: 5px;
}

.correct-answer {
    font-size: 1.5rem;
}

/* Test Microphone Button */
.test-mic-button {
    position: absolute;
    bottom: 20px;
    left: 20px;
    padding: 10px 15px;
    border-radius: 8px;
    border: 2px solid var(--color-primary);
    background: transparent;
    color: var(--color-primary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.2s;
}

.test-mic-button:hover {
    background: var(--color-primary);
    color: white;
}

/* Microphone Button */
.mic-button {
    position: absolute;
    bottom: 20px;
    right: 20px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    border: none;
    background: var(--color-primary);
    font-size: 1.5rem;
    cursor: pointer;
    transition: transform 0.2s, background 0.2s;
}

.mic-button:hover {
    transform: scale(1.1);
    background: #ff6b6b;
}

.mic-button:active {
    transform: scale(0.95);
}

/* Instructions Footer */
.instructions {
    text-align: center;
    color: var(--color-muted);
}

.keyboard-hint {
    margin-top: 10px;
}

kbd {
    background: var(--color-secondary);
    padding: 5px 10px;
    border-radius: 5px;
    font-family: monospace;
}

/* Responsive Design */
@media (max-width: 480px) {
    .letter-display {
        font-size: 5rem;
    }

    .flashcard {
        padding: 30px 20px;
    }

    .stats-bar {
        flex-wrap: wrap;
    }

    .stat {
        min-width: 80px;
    }

    .timeout-control {
        justify-content: center;
    }
}