:root {
    --bg-color: #0d1117;
    --sidebar-bg: #161b22;
    --text-primary: #c9d1d9;
    --text-secondary: #8b949e;
    --accent-color: #58a6ff;
    --accent-glow: rgba(88, 166, 255, 0.15);
    --border-color: #30363d;
    --card-bg: #161b22;
    --hover-bg: #21262d;
    --font-main: 'Outfit', sans-serif;
    --font-code: 'JetBrains Mono', monospace;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-main);
    height: 100vh;
    overflow: hidden;
}

.app-container {
    display: flex;
    height: 100%;
}

/* Sidebar */
.sidebar {
    width: 300px;
    background-color: var(--sidebar-bg);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    transition: transform 0.3s ease;
    z-index: 100;
}

.logo-area {
    padding: 24px;
    border-bottom: 1px solid var(--border-color);
}

.logo-area h1 {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, #58a6ff 0%, #bc8cff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.logo-area p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 4px;
}

.nav-menu {
    flex: 1;
    overflow-y: auto;
    padding: 16px;
}

.nav-section {
    margin-bottom: 24px;
}

.nav-section-title {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-secondary);
    margin-bottom: 12px;
    padding-left: 12px;
    font-weight: 700;
}

.nav-item {
    display: block;
    padding: 10px 12px;
    margin-bottom: 4px;
    border-radius: 6px;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 0.95rem;
    transition: all 0.2s ease;
    cursor: pointer;
}

.nav-item:hover {
    background-color: var(--hover-bg);
    color: #fff;
}

.nav-item.active {
    background-color: var(--accent-glow);
    color: var(--accent-color);
    font-weight: 600;
}

.nav-folder {
    margin-left: 12px;
    border-left: 1px solid var(--border-color);
    padding-left: 12px;
    display: none;
}

.nav-folder.open {
    display: block;
}

.folder-title {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 12px;
    cursor: pointer;
    color: var(--text-secondary);
    border-radius: 6px;
    font-size: 0.9rem;
}

.folder-title:hover {
    background-color: var(--hover-bg);
    color: var(--text-primary);
}

.folder-title::after {
    content: '›';
    transition: transform 0.2s;
}

.folder-title.open::after {
    transform: rotate(90deg);
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    height: 100%;
    position: relative;
    overflow: hidden;
}

.top-bar {
    height: 64px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    padding: 0 24px;
    background-color: rgba(13, 17, 23, 0.8);
    backdrop-filter: blur(10px);
}

.breadcrumbs {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.content-viewer {
    flex: 1;
    overflow-y: auto;
    padding: 40px;
    max-width: 900px;
    margin: 0 auto;
    width: 100%;
}

/* Markdown Styling */
.markdown-body {
    line-height: 1.6;
    font-size: 1.05rem;
}

.markdown-body h1, .markdown-body h2, .markdown-body h3 {
    margin-top: 1.5em;
    margin-bottom: 0.5em;
    color: #fff;
    font-weight: 600;
}

.markdown-body h1 {
    font-size: 2.5rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.3em;
}

.markdown-body p {
    margin-bottom: 1.2em;
}

.markdown-body code {
    background-color: rgba(110, 118, 129, 0.4);
    padding: 0.2em 0.4em;
    border-radius: 6px;
    font-family: var(--font-code);
    font-size: 0.85em;
}

.markdown-body pre {
    background-color: #161b22;
    padding: 16px;
    border-radius: 8px;
    overflow-x: auto;
    margin-bottom: 1.5em;
    border: 1px solid var(--border-color);
}

.markdown-body pre code {
    background-color: transparent;
    padding: 0;
}

.markdown-body blockquote {
    border-left: 4px solid var(--accent-color);
    padding-left: 16px;
    color: var(--text-secondary);
    background: var(--hover-bg);
    padding: 16px 16px 16px 20px;
    border-radius: 0 8px 8px 0;
    margin-bottom: 1.5em;
}

.markdown-body ul, .markdown-body ol {
    margin-bottom: 1.5em;
    padding-left: 2em;
}

/* Welcome Screen */
.welcome-screen {
    text-align: center;
    padding-top: 100px;
}

.welcome-screen h2 {
    font-size: 2rem;
    margin-bottom: 16px;
    background: linear-gradient(135deg, #fff 0%, #aaa 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Mobile */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    margin-right: 16px;
}

@media (max-width: 768px) {
    .menu-toggle {
        display: block;
    }
    
    .sidebar {
        position: absolute;
        height: 100%;
        transform: translateX(-100%);
        box-shadow: 10px 0 30px rgba(0,0,0,0.5);
    }
    
    .sidebar.open {
        transform: translateX(0);
    }
    
    .content-viewer {
        padding: 24px;
    }
}