/* 全局样式和字体 */
:root {
    --primary-color: #4a4a4a;
    --secondary-color: #ff7f50; /* 珊瑚色，用于高亮 */
    --background-color: #f4f4f9;
    --card-bg-color: #ffffff;
    --correct-color: #28a745;
    --wrong-color: #dc3545;
    --font-jp: 'Noto Sans JP', sans-serif;
    --font-en: 'Roboto', sans-serif;
}

body {
    font-family: var(--font-en);
    line-height: 1.6;
    margin: 0;
    padding: 0;
    background-color: var(--background-color);
    color: var(--primary-color);
}

/* 头部 */
header {
    background: var(--secondary-color);
    color: white;
    text-align: center;
    padding: 2rem 1rem;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

header h1 {
    font-family: var(--font-jp);
    margin: 0;
    font-size: 2.8rem;
    font-weight: 700;
}

header p {
    margin: 0;
    font-size: 1.2rem;
}

/* 主内容区域 */
main {
    padding: 1.5rem;
    max-width: 1200px;
    margin: 0 auto;
}

.card {
    background: var(--card-bg-color);
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
}

h2 {
    font-family: var(--font-jp);
    color: var(--secondary-color);
    text-align: center;
    margin-top: 0;
    margin-bottom: 1.5rem;
    font-size: 2rem;
}

h3 {
    font-family: var(--font-en);
    border-bottom: 2px solid var(--secondary-color);
    padding-bottom: 0.5rem;
    margin-top: 2rem;
    margin-bottom: 1.5rem;
}

/* 五十音图表 */
.gojuon-chart .intro {
    text-align: center;
    color: #6c757d;
    margin-bottom: 2rem;
}

.kana-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
    gap: 15px;
    text-align: center;
}

.kana-item {
    background-color: #f9f9f9;
    border-radius: 8px;
    padding: 10px 5px;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
    border: 1px solid #ddd;
}

.kana-item:hover {
    background-color: #ffede6;
    transform: scale(1.05);
}

.kana-item .hira {
    font-family: var(--font-jp);
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
}

.kana-item .kata {
    font-family: var(--font-jp);
    font-size: 2rem;
    font-weight: 700;
    color: #007bff; /* 蓝色区分片假名 */
}

.kana-item .romaji {
    font-family: var(--font-en);
    font-size: 0.9rem;
    color: #6c757d;
}

.kana-item.empty {
    background-color: transparent;
    border: none;
    cursor: default;
}

/* 测验部分 */
#quiz-options {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 20px;
    margin-bottom: 2rem;
}

.option-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

select, input[type="number"] {
    padding: 10px;
    border-radius: 8px;
    border: 1px solid #ccc;
    font-size: 1rem;
    width: 150px;
}

button {
    padding: 12px 25px;
    font-size: 1rem;
    font-weight: bold;
    color: white;
    background-color: var(--secondary-color);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
}

button:hover {
    background-color: #e66a42;
    transform: translateY(-2px);
}

.hidden {
    display: none !important;
}

#quiz-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
    font-weight: 500;
}

.question-card {
    font-family: var(--font-jp);
    font-size: 8rem;
    font-weight: bold;
    text-align: center;
    margin: 2rem 0;
    padding: 2rem;
    background-color: #f9f9f9;
    border-radius: 10px;
    min-height: 150px; /* 确保高度一致 */
    display: flex;
    justify-content: center;
    align-items: center;
}
.question-card.romaji-question {
    font-family: var(--font-en);
    font-size: 5rem;
    color: var(--primary-color);
}

#answer-input {
    width: 100%;
    padding: 15px;
    font-size: 1.2rem;
    text-align: center;
    border: 2px solid #ccc;
    border-radius: 8px;
    box-sizing: border-box;
    transition: border-color 0.3s;
}

#answer-input:focus {
    outline: none;
    border-color: var(--secondary-color);
}
#multiple-choice-options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-top: 1rem;
}
.choice-btn {
    padding: 20px;
    font-family: var(--font-jp);
    font-size: 2.5rem;
    background-color: var(--card-bg-color);
    color: var(--primary-color);
    border: 2px solid #ddd;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease-in-out;
}
.choice-btn:hover:not(:disabled) {
    border-color: var(--secondary-color);
    transform: translateY(-3px);
}

.choice-btn:disabled {
    cursor: not-allowed;
    opacity: 0.7;
}

.choice-btn.correct-choice {
    background-color: var(--correct-color);
    border-color: var(--correct-color);
    color: white;
}

.choice-btn.wrong-choice {
    background-color: var(--wrong-color);
    border-color: var(--wrong-color);
    color: white;
}

#feedback {
    text-align: center;
    font-size: 1.2rem;
    font-weight: bold;
    margin-top: 1rem;
    height: 30px;
}

#feedback.correct {
    color: var(--correct-color);
}

#feedback.wrong {
    color: var(--wrong-color);
}

#quiz-results {
    text-align: center;
}

#final-score {
    font-size: 2.5rem;
    font-weight: bold;
    color: var(--secondary-color);
}

#result-summary {
    font-size: 1.2rem;
}

/* 页脚 */
footer {
    text-align: center;
    padding: 2rem;
    margin-top: 2rem;
    background-color: #333;
    color: #ccc;
    font-size: 0.9rem;
}

footer a {
    color: #fff;
    text-decoration: none;
    transition: color 0.3s;
}

footer a:hover {
    color: var(--secondary-color);
}

footer img {
    width: 16px;
    height: 16px;
}

/* 响应式设计 - 适配手机 */
@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }
    header p {
        font-size: 1rem;
    }

    main {
        padding: 1rem;
    }
    
    .card {
        padding: 1.5rem;
    }

    .kana-grid {
        grid-template-columns: repeat(auto-fill, minmax(60px, 1fr));
        gap: 10px;
    }

    .kana-item .hira, .kana-item .kata {
        font-size: 1.5rem;
    }
    
    .question-card {
        font-size: 6rem;
        min-height: 120px;
    }
    .question-card.romaji-question {
        font-size: 4rem;
    }

    .choice-btn {
        font-size: 2rem;
        padding: 15px;
    }

    #quiz-options {
        flex-direction: column;
        align-items: stretch;
    }

    select, input[type="number"] {
        width: 100%;
    }
}