:root {
            --academic-blue:#0f172a;
            --ink-black:#1a1a1a;
            --paper-white:#ffffff;
            --muted-gray:#64748b;
            --border-light:#e2e8f0;
        }

        body {
            font-family:'Inter',sans-serif;
            background:#f1f5f9;
            color:var(--ink-black);
            line-height:1.8;
        }

        .paper-container {
            background:var(--paper-white);
            min-height:100vh;
            border-left:1px solid var(--border-light);
            border-right:1px solid var(--border-light);
            box-shadow:0 0 40px rgba(0,0,0,.05);
        }

        h1,h2,h3 {
            font-family:'Crimson Pro',serif;
            color:var(--academic-blue);
        }

        .manuscript-title {
            font-size:2.8rem;
            font-weight:700;
        }

        .doc-meta {
            font-family:'Fira Mono',monospace;
            font-size:.7rem;
            color:var(--muted-gray);
            letter-spacing:.05em;
            text-transform:uppercase;
        }

        .index-box { border:1px solid var(--border-light); }
        .table-index { font-size:.85rem; }

        .table-index thead th {
            background:#fafafa;
            border-bottom:2px solid var(--academic-blue);
            font-size:.7rem;
            letter-spacing:1px;
        }

        .category-header {
            background:#f8fafc;
            font-weight:700;
            font-size:.7rem;
        }

        .q-number {
            font-family:'Fira Mono',monospace;
            color:var(--muted-gray);
            width:70px;
            font-size:.75rem;
        }

        pre {
            background:#f8fafc;
            border:1px solid var(--border-light);
            padding:20px;
            font-family:'Fira Mono',monospace;
            font-size:.8rem;
        }

        .question-detail {
            margin-top:4rem;
            padding-top:3rem;
            border-top:1px solid var(--border-light);
            scroll-margin-top:100px;
        }

        .doc-id-sticky {
            position:fixed;
            top:20px;
            right:20px;
            transform:rotate(90deg);
            transform-origin:right bottom;
            font-family:'Fira Mono',monospace;
            font-size:.65rem;
            color:var(--muted-gray);
        }

     /* Sidebar Styling */
     .download-callout {
        border: 1px solid #e2e8f0;
    padding: 30px;
    background: #fff;
}
    .btn-download-main { background-color: var(--academic-blue); color: white; font-weight: 600; text-transform: uppercase; font-size: 0.75rem; letter-spacing: 1px; width: 100%; border-radius: 0; padding: 14px; border: 1px solid var(--academic-blue); } .btn-download-main:hover { background: transparent; color: var(--academic-blue); }

        @media(max-width:991px){
            .doc-id-sticky{display:none;}
            .manuscript-title{font-size:2rem;}
        }

        .back-ref {
    margin-top: 2.5rem;
    padding-top: 1rem;
    border-top: 1px dashed var(--border-light);
}

.back-to-toc {
    font-family: 'Fira Mono', monospace;
    font-size: 0.65rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--muted-gray);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.back-to-toc::before {
    content: "↩";
    font-size: 0.7rem;
    opacity: 0.7;
}

.back-to-toc:hover {
    color: var(--academic-blue);
    text-decoration: underline;
}
        /* Search/Filter Bar - Academic Style */
        .search-box {
            border: 1px solid var(--border-muted);
            border-radius: 0;
            padding: 12px 15px;
            font-family: 'Fira Mono', monospace;
            font-size: 0.85rem;
            margin-bottom: 40px;
            width: 100%;
            background-color: #fff;
        }

        /* Catalog Entry Styling */
        .catalog-item {
            padding: 30px 0;
            border-bottom: 1px solid var(--border-muted);
            transition: background 0.2s;
        }
        .catalog-item:hover { background-color: #f9f9f9; }

        .item-ref {
            font-family: 'Fira Mono', monospace;
            font-size: 0.7rem;
            color: #999;
            display: block;
            margin-bottom: 0.5rem;
        }

        .item-title {
            text-decoration: none;
            color: var(--academic-blue);
            font-size: 1.6rem;
            font-weight: 700;
            display: block;
            line-height: 1.2;
            margin-bottom: 10px;
        }
        .item-title:hover { text-decoration: underline; }

        .item-abstract {
            font-size: 0.9rem;
            color: #555;
            text-align: justify;
            margin-bottom: 15px;
        }

        .item-tags {
            font-family: 'Fira Mono', monospace;
            font-size: 0.65rem;
            color: var(--academic-blue);
            font-weight: 600;
        }

        .logo{
            text-decoration: none;
            color: #0f172a;
        }
        
        .doc-breadcrumb {
    font-size: 13px;
    margin-bottom: 24px;
    font-size: 10px;
}

.doc-breadcrumb ol {
    display: flex;
    
    flex-wrap: wrap;
    list-style: none;
    padding: 0;
    margin: 0;
}

.doc-breadcrumb li {
    color: #6b7280; /* neutral gray */
}

.doc-breadcrumb li + li::before {
    content: "›";
    margin: 0 8px;
    color: #9ca3af;
}

.doc-breadcrumb a {
    color: #2563eb; /* docs-blue */
    text-decoration: none;
}

.doc-breadcrumb a:hover {
    text-decoration: underline;
}