/* 首页特定样式 */
body {
    background-color: #f0f7ff;
    font-family: 'Poppins', 'Microsoft YaHei', sans-serif;
    color: #333;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    text-align: center;
}

.header {
    padding: 20px;
    background-color: #ffffff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    border-radius: 0 0 15px 15px;
}

.textbook-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: #3a86ff;
}

.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
}

.welcome-section {
    text-align: center;
    margin-bottom: 50px;
}

.welcome-section h1 {
    font-size: 2.5rem;
    color: #2b2d42;
    margin-bottom: 10px;
    animation: fadeIn 1s ease-in-out;
}

.welcome-section p {
    font-size: 1.2rem;
    color: #6c757d;
    animation: fadeIn 1.5s ease-in-out;
}

.mode-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-top: 40px;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
}

.mode-card {
    background: #ffffff;
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
}

.mode-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
}

.mode-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.mode-card h2 {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 24px;
    color: #2c3e50;
    margin-bottom: 15px;
}

.mode-card p {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 16px;
    color: #7f8c8d;
    line-height: 1.5;
}

.mode-btn {
    padding: 12px 30px;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.learn-btn {
    background-color: #3a86ff;
    color: white;
}

.learn-btn:hover {
    background-color: #2667cc;
}

.quiz-btn {
    background-color: #ff6b6b;
    color: white;
}

.quiz-btn:hover {
    background-color: #e05050;
}

.footer {
    text-align: center;
    padding: 20px;
    color: #6c757d;
    font-size: 0.9rem;
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(50px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 响应式调整 */
@media (max-width: 1024px) {
    .mode-container {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
        padding: 0 20px;
    }
}

@media (max-width: 768px) {
    .mode-container {
        grid-template-columns: 1fr;
        gap: 20px;
        padding: 0 15px;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 28px;
        margin-bottom: 20px;
    }
    
    .mode-container {
        gap: 15px;
        margin-top: 20px;
    }
    
    .mode-card {
        padding: 15px;
    }
    
    .mode-icon {
        font-size: 32px;
        margin-bottom: 10px;
    }
    
    .mode-card h2 {
        font-size: 18px;
        margin-bottom: 8px;
    }
    
    .mode-card p {
        font-size: 13px;
    }
}