* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "Microsoft YaHei", sans-serif;
    background-color: #f0f2f5;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    padding: 1rem;
}

.container {
    background-color: white;
    padding: 1.5rem;
    border-radius: 1rem;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 500px;
    margin-top: 2rem;
}

h1 {
    text-align: center;
    color: #333;
    margin-bottom: 1.5rem;
    font-size: 1.8rem;
}

.question {
    margin-bottom: 1rem;
    padding: 0.8rem;
    background-color: #f8f9fa;
    border-radius: 0.5rem;
}

.question-text {
    font-size: 1.1rem;
    margin-bottom: 0.3rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

input[type="number"] {
    width: 80px;
    padding: 0.4rem;
    font-size: 1rem;
    border: 2px solid #ddd;
    border-radius: 0.3rem;
    text-align: center;
}

button {
    display: block;
    width: 100%;
    padding: 0.8rem;
    font-size: 1.1rem;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 0.5rem;
    cursor: pointer;
    margin-top: 0.8rem;
    transition: all 0.3s;
}

button:hover:not(:disabled) {
    background-color: #45a049;
}

button:disabled {
    background-color: #cccccc;
    cursor: not-allowed;
    opacity: 0.7;
}

.hidden {
    display: none;
}

#result-container {
    text-align: center;
    margin-top: 1.5rem;
    min-height: 100px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

#stars-container {
    font-size: 2rem;
    margin: 0.8rem 0;
    min-height: 2.5rem;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.star {
    color: gold;
    margin: 0 0.2rem;
}

.correct {
    color: #4CAF50;
}

.incorrect {
    color: #f44336;
}

.wrong-mark {
    color: #f44336;
    font-size: 1.1rem;
    font-weight: bold;
    margin-left: 0.3rem;
}

.reward-icon {
    font-size: 2rem;
    animation: popIn 0.3s ease-out;
}

@keyframes popIn {
    0% {
        transform: scale(0);
    }
    70% {
        transform: scale(1.2);
    }
    100% {
        transform: scale(1);
    }
}