/* 通用重置样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    background-color: #f5f5f5;
}

/* 容器样式 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    background-color: white;
}

/* 导航栏样式 */
.navbar {
    background: linear-gradient(to right, #ff6b6b, #4ecdc4);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
}

.nav-menu {
    display: flex;
    list-style: none;
}

.nav-menu li {
    margin: 0 10px;
}

.nav-menu a {
    color: white;
    text-decoration: none;
    padding: 8px 15px;
    border-radius: 4px;
    transition: background-color 0.3s;
}

.nav-menu a:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

.auth-buttons {
    display: flex;
    gap: 10px;
}

.auth-buttons button {
    padding: 8px 15px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

.login-btn {
    background-color: transparent;
    color: white;
    border: 1px solid white;
}

.register-btn {
    background-color: #ff9f43;
    color: white;
}

/* 标题样式 */
.section-title {
    text-align: center;
    padding: 10px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    font-size: 2rem;
    font-weight: bold;
}

/* 内容区样式 */
.content {
    padding: 30px;
    text-align: center;
}

/* 预览页面样式 */
.preview-header {
    background: linear-gradient(to right, #ff6b6b, #4ecdc4);
    padding: 1rem 0;
    text-align: center;
    color: white;
    position: sticky;
    top: 0;
    z-index: 100;
}

.preview-content {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: auto;
    padding: 20px;
}

.preview-image {
    max-width: 100%;
    max-height: 80vh;
    object-fit: contain;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

.preview-footer {
    background-color: #333;
    color: white;
    padding: 15px 0;
    text-align: center;
}

.chapter-info {
    margin-bottom: 10px;
    font-size: 1.1rem;
}

.chapter-navigation {
    display: flex;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
}

.chapter-btn {
    padding: 8px 12px;
    background-color: #555;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.chapter-btn:hover {
    background-color: #777;
}

.chapter-btn.active {
    background-color: #4ecdc4;
}

.chapter-locked {
    background-color: #888 !important;
    opacity: 0.6;
    cursor: not-allowed;
}

.chapter-locked:hover {
    background-color: #888 !important;
}

.navigation-btn {
    position: fixed;
    top: 50%;
    transform: translateY(-50%);
    background-color: rgba(0,0,0,0.5);
    color: white;
    border: none;
    padding: 15px;
    cursor: pointer;
    font-size: 1.5rem;
    border-radius: 50%;
    z-index: 200;
}

.prev-btn {
    left: 20px;
}

.next-btn {
    right: 20px;
}

/* 底部样式 */
.footer {
    background-color: #333;
    color: white;
    padding: 30px 0;
    text-align: center;
    margin-top: 40px;
}

.footer-info {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    text-align: left;
}

.footer-info p {
    margin: 5px 0;
    font-size: 0.9rem;
    color: #ccc;
}

.footer-info .address {
    font-weight: bold;
    color: white;
}