:root {
    --sidebar-bg: #343131;
    --sidebar-hover: #4e4a4a;
    --text-muted: #808080;
    --link-color: #2980b9;
    --font-main: "Lato", "proxima-nova", "Helvetica Neue", Arial, sans-serif;
}

/* 基础重置，保证 100% 高度可用 */
* { box-sizing: border-box; }
html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* 顶层布局：两个独立滚动区域（sidebar 与 content） */
/* overflow:hidden 防止 body 自身产生滚动条，两个子区域分别控制滚动 */
.layout {
    display: flex;
    min-height: 100vh;
    height: 100vh;
    overflow: hidden;
    background: #edf0f2;
}

/* 侧边栏：固定宽度、高度为视口高度，内部滚动 */
.sidebar {
    width: 300px;
    background: var(--sidebar-bg);
    color: white;
    padding: 0;
    position: sticky;
    top: 0;
    height: 100vh;
    z-index: 1000;
    overflow-y: auto;                 /* 启用侧边栏内部滚动 */
    -webkit-overflow-scrolling: touch; /* iOS 平滑滚动 */
}

/* 侧边栏头部 */
.sidebar h2 {
    font-size: 1.1rem;
    padding: 20px;
    background: #2980b9;
    margin: 0;
    cursor: pointer;
    text-align: center;
}

/* 搜索框 */
.sidebar input {
    width: 90%;
    margin: 15px 5%;
    padding: 8px;
    background: #4e4a4a;
    border: 1px solid #666;
    color: white;
    border-radius: 20px;
}

/* 导航 */
.menu-title {
    padding: 10px 20px;
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    font-weight: bold;
}

.menu-list { list-style: none; margin: 0; padding: 0; }
.menu-list li a {
    display: block;
    padding: 10px 25px;
    color: #ccc;
    text-decoration: none;
    font-size: 0.9rem;
    border-bottom: 1px solid #444;
}

.menu-list li a:hover {
    background: var(--sidebar-hover);
    color: white;
}

.menu-list li a.active {
    background: var(--sidebar-hover);
    color: white;
    border-left: 3px solid var(--link-color);
    padding-left: 22px;
}

/* 内容区：占据剩余宽度，高度为视口高度，开启独立滚动 */
.content {
    flex: 1;
    height: 100vh;
    overflow-y: auto;                 /* 启用内容区内部滚动 */
    -webkit-overflow-scrolling: touch; /* iOS 平滑滚动 */
    background: white;
    padding: 0px 180px 50px 50px;
    box-shadow: -2px 0 5px rgba(0,0,0,0.05);
    opacity: 0; /* 初始隐藏 */
    transition: opacity 0.4s ease, transform 0.4s ease; /* 关键：同时监听透明度和位移 */
}

/* 激活状态：通用 */
.content.active {
    opacity: 1 !important;
    transform: translateY(0) !important;
}

/* 导航按钮样式 */
.nav-btn {
    padding: 12px 24px;
    background-color: #2980b9; /* 蓝色 */
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 15px;
    font-weight: bold;
    transition: all 0.2s ease;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.nav-btn:hover {
    background-color: #3498db;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}

.nav-btn:active {
    transform: translateY(0);
}
/* 1. 淡入淡出模式 (默认) - 初始状态无位移 */
.anim-mode-fade {
    transform: translateY(0);
}

/* 2. 位移模式 - 初始状态有位移 */
.anim-mode-slide {
    /* 位移量由 JS 动态设置 */
}

/* 针对 Markdown 内部元素的间距优化 */
.content h1, .content h2, .content h3 {
    margin-top: 1.5em;    /* 增加标题上方的间距 */
    margin-bottom: 0.8em; /* 标题与正文的间距 */
    line-height: 1.3;
}

.content p {
    line-height: 1.8;     /* 增加行高，显著提升阅读舒适度 */
    margin-bottom: 1.2em; /* 段落之间的间距 */
}

.content ul, .content ol {
    padding-left: 20px;   /* 列表缩进 */
    margin-bottom: 1.2em;
}
.file-card {
    border-left: 4px solid #2980b9;
    background: #f9f9f9;
    padding: 15px;
    margin-bottom: 20px;
}

.file-card ul { list-style: none; padding-left: 10px; margin: 0; }
.file-card li { margin: 8px 0; }
.file-card a { color: var(--link-color); text-decoration: none; }
.file-card a:hover { text-decoration: underline; }

/* 添加加载动画 */
.loading-spinner {
    display: inline-block;
    width: 50px;
    height: 50px;
    border: 3px solid #f3f3f3;
    border-top: 3px solid #2980b9;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto;
}

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

/* 确保警告框在侧栏右侧显示时位置正确（保留原逻辑的 left:300px） */
@media (max-width: 720px) {
    /* 小屏时把侧栏改为顶部滑出或其它行为（简单处理） */
    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
        overflow: visible;
    }
    .layout { flex-direction: column; height: auto; }
    .content { height: auto; overflow: visible; padding: 20px; }
}
#welcome-title {
    cursor: pointer;
    user-select: none; /* 防止频繁点击导致文字被选中蓝光 */
    transition: opacity 0.2s;
}

#welcome-title:hover {
    opacity: 0.8; /* 悬停反馈 */
}

/* 右侧个性化侧拉菜单 */
.user-settings-panel {
    position: fixed;
    right: 20px;
    top: 20px;
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 15px;
    z-index: 1000;
}

/* 每一个设置项的组合容器 */
.setting-group {
    position: relative;
    display: flex;
    align-items: center;
}

/* --- 修正右侧面板基础样式 --- */
.setting-item {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 12px;
    cursor: pointer;
    color: #888;
    transition: all 0.3s ease;
    white-space: nowrap; /* 保持外部文字不换行 */
    padding: 8px 15px;
}

.setting-item:hover {
    color: var(--link-color);
    transform: translateX(-5px);
    background: #fff;
}

/* 确保 hover 时显示 */
.setting-item:hover .setting-submenu {
    display: flex;
    animation: fadeInRight 0.2s ease;
}

@keyframes fadeInRight {
    from { opacity: 0; transform: translateX(10px); }
    to { opacity: 1; transform: translateX(0); }
}

.setting-item .icon { font-size: 1.2rem; }
.setting-item span { font-size: 0.9rem; font-weight: 500; }

/* 修正二级菜单：紧贴图标并修复布局 */
.setting-submenu {
    position: absolute;
    /* 核心修改：使用固定偏移量而非百分比，使其紧贴左侧 */
    right: 90%;
    top: 10px;    /* 稍微向上偏移，对齐图标中心 */
    margin-right: 10px; /* 控制菜单与图标的间距 */

    background: white;
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
    border-radius: 12px;
    padding: 15px;
    display: none; /* 默认隐藏 */
    min-width: 180px;
    z-index: 1001;

    /* 修复之前提到的重叠问题 */
    white-space: normal;
    flex-direction: column;
    gap: 10px;
}

/* 优化二级菜单内的输入框和按钮 */
.setting-submenu input {
    width: 100%;
    padding: 6px;
    border: 1px solid #ddd;
    border-radius: 4px;
    box-sizing: border-box; /* 确保 padding 不撑开宽度 */
}

.setting-submenu button {
    width: 100%;
    padding: 8px;
    background: var(--link-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 12px;
    transition: background 0.2s;
}

.setting-submenu button:hover {
    background: #216a94;
}
.setting-submenu div:hover {
    color: var(--link-color);
    background: #f5f5f5;
}


/* --- 弹出的参数设置 UI 界面 --- */
.settings-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4); /* 朦胧遮罩 */
    display: none; /* 默认隐藏 */
    justify-content: center;
    align-items: center;
    z-index: 2000;
    backdrop-filter: blur(4px); /* 高级感毛玻璃 */
}

.modal-content {
    background: white;
    width: 400px;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 20px 50px rgba(0,0,0,0.15);
    position: relative;
    animation: modalSlideUp 0.3s ease-out;
}

@keyframes modalSlideUp {
    from { transform: translateY(30px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.modal-close {
    position: absolute;
    right: 20px;
    top: 20px;
    cursor: pointer;
    font-size: 20px;
    color: #ccc;
}

/* UI 内部控件样式 */
.control-group { margin-bottom: 20px; }
.control-group label { display: block; margin-bottom: 8px; font-weight: bold; font-size: 14px; }
.control-group input[type="range"] { width: 100%; cursor: pointer; }