:root {
    --bg-color: #f8f6f1; /* Warm off-white */
    --text-main: #2b2b2b;
    --text-muted: #666666;
    --sidebar-bg: #111111;
    --border-color: #dfdbd3;
    --font-inter: "Inter", system-ui, sans-serif;
}

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

body {
    font-family: var(--font-inter);
    background-color: var(--bg-color);
    color: var(--text-main);
    display: flex;
    min-height: 100vh;
    line-height: 1.6;
}

/* Left Vertical Sidebar */
.global-sidebar {
    width: 60px;
    background-color: var(--sidebar-bg);
    color: white;
    position: fixed;
    height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 2rem 0;
    writing-mode: vertical-rl;
    text-orientation: mixed;
    font-size: 0.85rem;
    letter-spacing: 2px;
}

/* Main Content Area */
.main-wrapper {
    margin-left: 60px; /* Offset for sidebar */
    padding: 4rem;
    width: 100%;
    max-width: 1400px;
}

/* Landing Page Grid (Based on image_e7d035.png) */
.hero-title {
    font-size: 5rem;
    font-weight: 400;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    color: var(--text-muted);
    max-width: 600px;
    margin-bottom: 4rem;
}

.post-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
}

.post-card {
    border: 1px solid var(--border-color);
    padding: 2rem;
    text-decoration: none;
    color: var(--text-main);
    transition: background-color 0.2s ease;
}

.post-card:hover {
    background-color: #f0eee8;
}

.post-card h3 {
    font-size: 1.5rem;
    font-weight: 400;
    margin-bottom: 2rem;
}

.post-meta {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Article Layout with ToC (Based on image_e77e9a.jpg) */
.article-layout {
    display: grid;
    grid-template-columns: 1fr 250px;
    gap: 4rem;
    max-width: 1000px;
    margin: 0 auto;
}

.article-content p {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

/* Graphs and Code Blocks */
.article-content figure,
.article-content pre {
    border: 1px solid var(--border-color);
    background-color: #ffffff;
    padding: 2rem;
    margin: 2rem 0;
}

.article-content figcaption {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 1rem;
    line-height: 1.4;
}

/* Table of Contents */
.toc-sidebar {
    position: sticky;
    top: 4rem;
    height: max-content;
}

.toc-title {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
    margin-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.toc-link {
    display: block;
    text-decoration: none;
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 0.75rem;
}

.toc-link.active,
.toc-link:hover {
    color: var(--text-main);
    border-left: 2px solid var(--text-main);
    padding-left: 0.5rem;
}