/* UI/UX Pro Max Optimized Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --success-color: #4caf50;
    --error-color: #f44336;
    --background-light: #f5f7fa;
    --background-white: #ffffff;
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-light: #999999;
    --border-radius: 16px;
    --shadow-sm: 0 2px 10px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 5px 15px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 20px 40px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: 'Microsoft YaHei', 'PingFang SC', Arial, sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 800px;
    min-height: 600px;
    background: var(--background-white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    animation: fadeIn 0.5s ease-in-out;
}

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

.header {
    background: var(--primary-gradient);
    color: white;
    padding: 40px 30px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    animation: shine 3s infinite;
}

@keyframes shine {
    0% {
        left: -100%;
    }
    100% {
        left: 100%;
    }
}

.header h1 {
    font-size: 2.8rem;
    margin-bottom: 12px;
    font-weight: 700;
    position: relative;
    z-index: 1;
}

.header p {
    font-size: 1.2rem;
    opacity: 0.9;
    position: relative;
    z-index: 1;
}

.main {
    flex: 1;
    padding: 40px;
    display: flex;
    flex-direction: column;
    gap: 40px;
}

.poem-container {
    background: var(--background-light);
    border-radius: var(--border-radius);
    padding: 35px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.poem-container:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.poem-info {
    margin-bottom: 25px;
    text-align: center;
}

#poem-title {
    font-size: 2rem;
    color: var(--text-primary);
    margin-bottom: 12px;
    font-weight: 600;
}

#poem-author {
    font-size: 1.2rem;
    color: var(--text-secondary);
}

.poem-question {
    background: var(--background-white);
    border-radius: 12px;
    padding: 30px;
    margin: 25px 0;
    text-align: center;
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}

.poem-question::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: var(--primary-gradient);
}

#question {
    font-size: 1.8rem;
    line-height: 1.6;
    color: var(--text-primary);
    font-weight: 500;
}

.options {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 18px;
    margin: 25px 0;
}

.option {
    background: var(--background-white);
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    padding: 20px;
    font-size: 1.2rem;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.option:hover {
    border-color: var(--primary-color);
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(102, 126, 234, 0.2);
}

.option.correct {
    background: var(--success-color);
    color: white;
    border-color: var(--success-color);
    animation: pulse 0.5s ease-in-out;
}

.option.incorrect {
    background: var(--error-color);
    color: white;
    border-color: var(--error-color);
    animation: shake 0.5s ease-in-out;
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
    100% {
        transform: scale(1);
    }
}

@keyframes shake {
    0%, 100% {
        transform: translateX(0);
    }
    25% {
        transform: translateX(-5px);
    }
    75% {
        transform: translateX(5px);
    }
}

.feedback {
    margin: 25px 0;
    padding: 20px;
    border-radius: 12px;
    text-align: center;
    font-size: 1.2rem;
    font-weight: 600;
    animation: fadeIn 0.3s ease-in-out;
}

.feedback.correct {
    background: #e8f5e8;
    color: #2e7d32;
    border-left: 4px solid var(--success-color);
}

.feedback.incorrect {
    background: #ffebee;
    color: #c62828;
    border-left: 4px solid var(--error-color);
}

.controls {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin-top: 25px;
}

.btn {
    padding: 14px 28px;
    border: none;
    border-radius: 30px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    z-index: 1;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: 0.5s;
    z-index: -1;
}

.btn:hover::before {
    left: 100%;
}

.btn.primary {
    background: var(--primary-gradient);
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

.btn.primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4);
}

.btn.secondary {
    background: var(--background-light);
    color: var(--text-primary);
    border: 2px solid #e0e0e0;
}

.btn.secondary:hover {
    background: #e8eaf6;
    border-color: var(--primary-color);
    transform: translateY(-3px);
}

.stats {
    display: flex;
    justify-content: space-around;
    background: var(--background-light);
    border-radius: var(--border-radius);
    padding: 30px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.stats:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.stat-item {
    text-align: center;
    padding: 20px;
    border-radius: 12px;
    background: var(--background-white);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    flex: 1;
    margin: 0 10px;
}

.stat-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.stat-value {
    display: block;
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 8px;
    font-family: 'Courier New', monospace;
}

.stat-label {
    font-size: 1.1rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.footer {
    background: var(--background-light);
    padding: 25px;
    text-align: center;
    color: var(--text-secondary);
    font-size: 1rem;
    border-top: 1px solid #e0e0e0;
    position: relative;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 3px;
    background: var(--primary-gradient);
    border-radius: 3px;
}

/* Loading Animation */
.loading {
    display: inline-block;
    position: relative;
    width: 80px;
    height: 80px;
    margin: 20px auto;
}

.loading div {
    position: absolute;
    top: 33px;
    width: 13px;
    height: 13px;
    border-radius: 50%;
    background: var(--primary-color);
    animation-timing-function: cubic-bezier(0, 1, 1, 0);
}

.loading div:nth-child(1) {
    left: 8px;
    animation: loading1 0.6s infinite;
}

.loading div:nth-child(2) {
    left: 8px;
    animation: loading2 0.6s infinite;
}

.loading div:nth-child(3) {
    left: 32px;
    animation: loading2 0.6s infinite;
}

.loading div:nth-child(4) {
    left: 56px;
    animation: loading3 0.6s infinite;
}

@keyframes loading1 {
    0% {
        transform: scale(0);
    }
    100% {
        transform: scale(1);
    }
}

@keyframes loading3 {
    0% {
        transform: scale(1);
    }
    100% {
        transform: scale(0);
    }
}

@keyframes loading2 {
    0% {
        transform: translate(0, 0);
    }
    100% {
        transform: translate(24px, 0);
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    body {
        padding: 10px;
    }
    
    .container {
        margin: 10px;
        min-height: auto;
        border-radius: 12px;
    }
    
    .header {
        padding: 30px 20px;
    }
    
    .header h1 {
        font-size: 2rem;
    }
    
    .header p {
        font-size: 1rem;
    }
    
    .main {
        padding: 20px;
        gap: 30px;
    }
    
    .poem-container {
        padding: 20px;
        border-radius: 12px;
    }
    
    #poem-title {
        font-size: 1.5rem;
    }
    
    #poem-author {
        font-size: 1rem;
    }
    
    .poem-question {
        padding: 20px;
        margin: 20px 0;
    }
    
    #question {
        font-size: 1.3rem;
        line-height: 1.5;
    }
    
    .options {
        grid-template-columns: 1fr;
        gap: 12px;
        margin: 20px 0;
    }
    
    .option {
        padding: 16px;
        font-size: 1.1rem;
        border-radius: 10px;
    }
    
    .feedback {
        margin: 20px 0;
        padding: 16px;
        font-size: 1.1rem;
    }
    
    .controls {
        flex-direction: column;
        align-items: center;
        gap: 12px;
        margin-top: 20px;
    }
    
    .btn {
        width: 100%;
        max-width: 280px;
        padding: 12px 24px;
        font-size: 1rem;
    }
    
    .stats {
        flex-direction: column;
        gap: 12px;
        padding: 20px;
        border-radius: 12px;
    }
    
    .stat-item {
        margin: 0;
        padding: 16px;
        border-radius: 10px;
    }
    
    .stat-value {
        font-size: 1.8rem;
    }
    
    .stat-label {
        font-size: 1rem;
    }
    
    .footer {
        padding: 20px;
        font-size: 0.9rem;
    }
}

/* Small mobile devices */
@media (max-width: 480px) {
    .header h1 {
        font-size: 1.8rem;
    }
    
    .main {
        padding: 15px;
    }
    
    .poem-container {
        padding: 15px;
    }
    
    #poem-title {
        font-size: 1.3rem;
    }
    
    #question {
        font-size: 1.1rem;
    }
    
    .option {
        padding: 14px;
        font-size: 1rem;
    }
    
    .btn {
        padding: 10px 20px;
        font-size: 0.9rem;
    }
    
    .stat-value {
        font-size: 1.6rem;
    }
}