/* CSS Reset 基础 */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    line-height: 1.6;
    min-height: 100vh;
}

code, pre, kbd, samp {
    font-family: Consolas, "Source Code Pro", "Courier New", monospace;
}

a {
    color: var(--link-color);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

img {
    max-width: 100%;
    height: auto;
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 60px;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    padding: 0 20px;
    z-index: 1000;
}

.navbar-brand {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-primary);
    white-space: nowrap;
}

.navbar-brand:hover {
    text-decoration: none;
}

.navbar-nav {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-left: 24px;
    flex: 1;
}

.navbar-right {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-left: auto;
}

/* Book 切换下拉菜单 */
.dropdown {
    position: relative;
}

.dropdown-toggle {
    background: none;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 6px 12px;
    color: var(--text-primary);
    cursor: pointer;
    font-size: 0.9rem;
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    min-width: 200px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    z-index: 1001;
    list-style: none;
}

.dropdown:hover .dropdown-menu,
.dropdown-menu.show {
    display: block;
}

.dropdown-menu li a {
    display: block;
    padding: 8px 16px;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.dropdown-menu li a:hover {
    background-color: var(--bg-secondary);
    text-decoration: none;
}

/* 用户菜单 */
.user-dropdown-toggle {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 0.9rem;
    color: var(--text-primary);
    padding: 4px 8px;
    border-radius: 4px;
}

.user-dropdown-toggle:hover {
    background-color: var(--bg-secondary);
}

.user-email {
    max-width: 150px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    display: inline-block;
    vertical-align: middle;
}

.dropdown-menu-right {
    right: 0;
    left: auto;
}

.dropdown-divider {
    margin: 4px 0;
    border-top: 1px solid var(--border-color);
}

/* 搜索框 */
.search-form {
    display: flex;
    align-items: center;
}

.search-input {
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 6px 12px;
    font-size: 0.9rem;
    background: var(--bg-primary);
    color: var(--text-primary);
    width: 200px;
}

.search-input::placeholder {
    color: var(--text-secondary);
}

/* 主题切换按钮 */
.theme-toggle {
    background: none;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 6px 10px;
    cursor: pointer;
    font-size: 1rem;
    color: var(--text-primary);
}

/* 用户菜单 */
.user-menu a,
.user-menu span {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* 主内容区域（导航栏下方） */
.main-content {
    margin-top: 60px;
    min-height: calc(100vh - 60px);
}

/* 响应式断点 */
@media (max-width: 1023px) {
    .navbar-nav {
        gap: 8px;
        margin-left: 12px;
    }

    .search-input {
        width: 140px;
    }
}

@media (max-width: 768px) {
    .navbar {
        padding: 0 12px;
    }

    .search-input {
        width: 120px;
    }

    .dropdown-toggle span.book-label {
        display: none;
    }
}

/* 错误页面 */
.error-page {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: calc(100vh - 160px);
    text-align: center;
    padding: 40px 20px;
}

.error-page h1 {
    font-size: 6rem;
    font-weight: 700;
    color: var(--text-secondary);
    line-height: 1;
    margin-bottom: 16px;
}

.error-page p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.error-page .btn-home {
    display: inline-block;
    margin-top: 24px;
    padding: 10px 24px;
    background-color: var(--link-color);
    color: #fff;
    border-radius: 4px;
    font-size: 1rem;
}

.error-page .btn-home:hover {
    text-decoration: none;
    opacity: 0.9;
}