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

body {
    font-family: 'Helvetica Neue', Helvetica, 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background-color: #f5f7fa;
}

.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.site-header {
    background: linear-gradient(135deg, #2d3e4b 0%, #1a2a36 100%);
    color: white;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.1);
}

.site-header .el-menu {
    background: transparent;
    border-bottom: none;
}

.site-header .el-menu-item {
    color: #f0f0f0;
    border-bottom: 2px solid transparent;
}

.site-header .el-menu-item:hover, .site-header .el-menu-item.is-active {
    color: #ffd966;
    border-bottom-color: #ffd966;
    background: rgba(255, 255, 255, 0.05);
}

.main-content {
    flex: 1;
    padding: 30px 20px;
    max-width: 1300px;
    margin: 0 auto;
    width: 100%;
}

.book-card {
    transition: all 0.3s ease;
    cursor: pointer;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.book-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.15);
}

.book-cover-placeholder {
    background: linear-gradient(145deg, #e9ecef, #dee2e6);
    height: 180px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 48px;
    color: #6c757d;
}

.chapter-item {
    padding: 12px 0;
    border-bottom: 1px solid #f0f0f0;
    transition: background 0.2s;
}

.chapter-item:hover {
    background: #fafbfc;
    padding-left: 6px;
}

.content-body {
    background: #fff9ef;
    padding: 40px 32px;
    border-radius: 24px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.05);
    line-height: 1.85;
    font-size: 18px;
    color: #2c3e4e;
    white-space: pre-wrap;
    word-break: break-word;
}

.action-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin: 32px 0 20px;
    flex-wrap: wrap;
}

.chapter-title {
    border-left: 6px solid #e6a017;
    padding-left: 20px;
    margin: 20px 0 30px;
    font-weight: 600;
    color: #2c3e4e;
}

@media (max-width: 768px) {
    .content-body {
        padding: 24px 18px;
        font-size: 16px;
    }

    .action-buttons {
        gap: 12px;
    }
}

.click-count-badge {
    color: #e6a017;
    font-weight: 500;
    font-size: 13px;
    margin-top: 8px;
}

.empty-tip {
    text-align: center;
    padding: 60px 0;
    color: #909399;
}