/* 书籍信息区域样式 */
.book-info {
    background: linear-gradient(135deg, #2c3e50, #3498db);
    padding: 60px 0 10px;
    color: white;
    position: relative;
    overflow: hidden;
}

.book-info::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('/images/pattern.png') repeat;
    opacity: 0.1;
}

.book-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
    z-index: 1;
    text-align: center;
}

.book-title {
    font-size: 2.5rem;
    font-weight: 900;
    margin-bottom: 20px;
    background: linear-gradient(45deg, #fff, #ffd700);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 2px 15px rgba(255,215,0,0.3);
    display: inline-block;
}

.book-description {
    font-size: 0.95rem;
    line-height: 1.8;
    opacity: 0.9;
    margin: 20px auto;
    max-width: 800px;
    padding: 15px 25px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    backdrop-filter: blur(5px);
}

.book-stats {
    display: flex;
    gap: 30px;
    margin-top: 20px;
    margin-bottom: 0;
    justify-content: center;
    flex-wrap: wrap;
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 10px;
    background: rgba(255, 255, 255, 0.1);
    padding: 8px 20px;
    border-radius: 20px;
    backdrop-filter: blur(5px);
}

.stat-icon {
    color: #ffd700;
    font-size: 1.2rem;
}

/* 章节容器样式 */
.chapters-container {
    position: relative;
    z-index: 0;
    max-width: 1200px;
    margin: 20px auto 120px;
    padding: 0 20px;
}

/* 章节头部样式 */
.chapters-header {
    margin-bottom: 0; /* 移除底部间距 */
    text-align: center;
}

.chapters-header h2 {
    font-size: 1.8rem;
    color: #2c3e50;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    margin: 0 0 5px 0; /* 只保留很小的底部间距 */
    line-height: 1;
}

.chapters-header h2 i {
    color: #ffd700;
    font-size: 1.8rem;
}

.chapter-title i {
    margin-right: 10px;
    color: #ffd700;
}

.section-item i {
    margin-right: 10px;
    width: 20px;
    text-align: center;
}

.section-item.locked {
    opacity: 0.5;
    cursor: not-allowed;
    color: #666;
}

.section-item.locked i {
    color: #999;
}

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

/* 修改小节序号样式 */
.section-number {
    margin-right: 10px;
    color: #666;
    font-weight: 500;
}

/* 修改小节标题样式 */
.section-item {
    padding: 15px 20px;
    border-bottom: 1px solid #eee;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
}

.section-item i {
    margin-right: 10px;
    width: 20px;
    text-align: center;
}

/* 重新设计学习交流区 */
.question-section {
    padding: 30px 0;
    background: linear-gradient(135deg, #2c3e50, #3498db);
    position: relative;
    overflow: hidden;
    margin-top: -100px;
    border-top: 1px solid rgba(255,255,255,0.1);
    z-index: 1;
}

/* 添加装饰背景 */
.question-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('/images/pattern.png') repeat;
    opacity: 0.1;
}

/* 添加波浪效果 */
.question-section::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 6px;
    background: linear-gradient(90deg, #ffd700, #ffeb3b, #ffd700);
    animation: shimmer 2s infinite linear;
}

.question-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
    text-align: center;
    position: relative;
    z-index: 1;
}

.question-header {
    margin-bottom: 30px;
    padding: 30px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
}

.question-header i {
    font-size: 3rem;
    background: linear-gradient(45deg, #fff, #ffd700);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 20px;
    display: inline-block;
    filter: drop-shadow(0 2px 4px rgba(0,0,0,0.2));
}

.question-header h2 {
    font-size: 1.8rem;
    color: white;
    margin: 15px 0;
    font-weight: 700;
    text-shadow: 0 2px 4px rgba(0,0,0,0.2);
    background: linear-gradient(45deg, #fff, #ffd700);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.subtitle {
    font-size: 1.1rem;
    color: #ffd700;
    margin: 12px 0 25px;
    font-weight: 500;
    text-shadow: 0 1px 2px rgba(0,0,0,0.2);
}

.question-list {
    text-align: left;
    max-width: 600px;
    margin: 0 auto;
}

.list-item {
    display: flex;
    align-items: flex-start;
    margin: 12px 0;
    color: rgba(255, 255, 255, 0.9);
    font-size: 1rem;
    line-height: 1.6;
}

.list-item .number {
    color: #ffd700;
    font-weight: 600;
    margin-right: 12px;
    font-size: 1rem;
}

.list-item .text {
    flex: 1;
}

.question-tip {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1rem;
    margin-top: 15px;
    line-height: 1.6;
    text-shadow: 0 1px 2px rgba(0,0,0,0.1);
}

.question-action {
    margin-top: 30px;
    position: relative;
}

/* 修改按钮样式，移除图标相关样式 */
.question-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 40px;
    background: linear-gradient(45deg, #fff, #ffd700);
    border-radius: 50px;
    color: #2c3e50;
    font-size: 1.1rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}

/* 移除按钮图标样式 */
.button-icon {
    display: none;
}

/* 添加装饰元素 */
.question-section .decoration {
    position: absolute;
    width: 200px;
    height: 200px;
    border-radius: 50%;
    background: linear-gradient(45deg, rgba(255,215,0,0.1), rgba(255,255,255,0.05));
    filter: blur(40px);
}

.decoration-1 {
    top: -100px;
    left: -100px;
}

.decoration-2 {
    bottom: -100px;
    right: -100px;
}

@keyframes shimmer {
    0% { background-position: -1000px; }
    100% { background-position: 1000px; }
}

/* 章节项样式 */
.chapter-item {
    background: white;
    border-radius: 15px;
    margin-top: 8px; /* 使用较小的顶部间距 */
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    overflow: hidden;
    transition: all 0.3s ease;
}

.chapter-item:first-child {
    margin-top: 5px; /* 第一个章节只需要很小的间距 */
}

/* 章节头部样式 */
.chapter-header {
    padding: 15px 20px;
    background: linear-gradient(135deg, #2c3e50, #3498db);
    color: white;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.chapter-title {
    font-size: 1.2rem;
    font-weight: 500;
    color: white;
    text-shadow: 1px 1px 1px rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
}

.chapter-title i {
    margin-right: 5px;
}

/* 章节数量样式 */
.section-count {
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.7);
    margin-left: 5px;
    font-weight: normal;
}

.chapter-text {
    margin: 0 5px;
}

.chapter-toggle {
    transition: transform 0.3s ease;
}

.chapter-toggle.active {
    transform: rotate(180deg);
}

.sections-list {
    padding: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.sections-list.active {
    max-height: 1000px;
}

.section-item {
    padding: 15px 20px;
    border-bottom: 1px solid #eee;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
}

.section-item:hover {
    background: rgba(26,35,126,0.05);
}

/* 加载动画 */
.loading-spinner {
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, #2c3e50, #3498db);
    position: fixed;
    top: 0;
    left: 0;
    transform: translateX(-100%);
    z-index: 1000;
    display: none;
}

.loading-spinner.active {
    display: block;
    animation: loading 1s infinite linear;
}

@keyframes loading {
    0% {
        transform: translateX(-100%);
    }
    100% {
        transform: translateX(100%);
    }
}

/* 内容区域样式 */
.section-content {
    background: #f8f9fa;
    margin: 0;
    overflow: hidden;
    transition: all 0.3s ease;
    width: 100%;
}

.section-content.hidden {
    display: none;
}

.content-wrapper {
    padding: 12px 15px;
    background: white;
    margin: 0 0 10px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.content-header {
    background: linear-gradient(135deg, #2c3e50, #3498db);
    color: white;
    padding: 25px;
}

.content-header h2 {
    font-size: 1.8rem;
    margin: 0;
    background: linear-gradient(45deg, #fff, #ffd700);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.content-body {
    padding: 0;
    line-height: 1.8;
    font-size: 1.1rem;
    color: #2c3e50;
}

/* 活动小节样式 */
.section-item.active {
    background: rgba(44, 62, 80, 0.1);
    color: #2c3e50;
    font-weight: 500;
}

/* 移动端调整 */
@media (max-width: 768px) {
    .chapters-header h2 {
        font-size: 1.5rem;
        margin: 0 0 3px 0;
    }
    
    .chapter-item:first-child {
        margin-top: 3px;
    }
    
    .chapter-item {
        margin-top: 6px;
    }
    
    .book-title {
        font-size: 2rem;
    }
    
    .book-description {
        font-size: 0.9rem;
        padding: 12px 20px;
    }
    
    .stat-item {
        padding: 6px 15px;
        font-size: 0.9rem;
    }
    
    .chapter-header {
        padding: 15px;
    }
    
    .chapter-title {
        font-size: 1.1rem;
    }
    
    .content-header h2 {
        font-size: 1.5rem;
    }
    
    .content-body {
        padding: 0;
        font-size: 1rem;
    }
    
    .question-section {
        margin-top: -100px;
    }
    
    .chapters-container {
        margin-bottom: 120px;
    }
    
    .book-info {
        padding: 40px 0 10px;
    }
    
    .book-stats {
        margin-top: 15px;
        margin-bottom: 0;
    }
    
    .quote-box {
        padding: 6px 10px;
        margin: 8px 0;
        background: rgba(255, 255, 255, 0.1);
        -webkit-backdrop-filter: blur(5px);
        backdrop-filter: blur(5px);
        background: rgba(255, 255, 255, 0.15);
    }
    
    .quote-text {
        font-size: 0.9rem;
        text-align: left;
        opacity: 0.9;
    }
    
    .question-header h2 {
        font-size: 1.6rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .list-item, 
    .list-item .number,
    .question-tip {
        font-size: 0.95rem;
    }
    
    .content-wrapper {
        padding: 10px 12px;
        font-size: 1rem;
    }
    
    .section-count {
        font-size: 0.8rem;
    }
}

/* 对不支持backdrop-filter的浏览器使用备用样式 */
@supports not (backdrop-filter: blur(5px)) {
    .quote-box {
        background: rgba(255, 255, 255, 0.25);
    }
}

/* 引用框样式 */
.quote-box {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 15px;
    padding: 8px 12px;
    margin: 10px 0;
    -webkit-backdrop-filter: blur(5px);
    backdrop-filter: blur(5px);
    background: rgba(255, 255, 255, 0.15);
}

.quote-text {
    color: rgba(255, 255, 255, 0.95);
    font-size: 0.95rem;
    line-height: 1.5;
    text-shadow: 0 1px 2px rgba(0,0,0,0.1);
    text-align: left;
    opacity: 0.9;
}

/* 加载动画样式 */
.loader {
    display: flex;
    justify-content: center;
    padding: 10px 0;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid transparent;
    border-radius: 50%;
    border-top: 3px solid #3498db;
    border-right: 3px solid #f1c40f;
    border-bottom: 3px solid #3498db;
    border-left: 3px solid #f1c40f;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 活动小节样式 */
.section-item.active {
    background: rgba(44, 62, 80, 0.1);
    color: #2c3e50;
    font-weight: 500;
}

/* 操作按钮样式 */
.action-buttons {
    margin: 20px 0 0;
    display: flex;
    gap: 15px;
    justify-content: flex-start;
}

.action-button {
    padding: 8px 20px;
    border: none;
    border-radius: 25px;
    color: white;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.join-button {
    background: linear-gradient(45deg, #2c3e50, #3498db);
}

.consult-button {
    background: linear-gradient(45deg, #3498db, #2ecc71);
}

.action-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

@media (max-width: 768px) {
    .action-buttons {
        margin: 15px 0 0;
        gap: 10px;
    }
    
    .action-button {
        padding: 6px 15px;
        font-size: 0.9rem;
    }
}

/* 错误消息样式 */
.error-message {
    color: #e74c3c;
    text-align: center;
    padding: 15px;
    font-size: 0.95rem;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 60px;
}

/* 升级链接样式 */
.upgrade-link {
    color: #3498db;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
}

.upgrade-link:hover {
    color: #2980b9;
    text-decoration: underline;
}

@media (max-width: 768px) {
    .error-message {
        padding: 10px;
        font-size: 0.9rem;
        min-height: 50px;
    }
    
    .upgrade-link {
        font-weight: 600;
    }
}