/* ── Tokens ── */
    :root {
        --ink: #0F172A;
        --ink-light: #64748B;
        --paper: #F9FAFB;
        --paper-mid: #E2E8F0;
        --surface: #FFFFFF;
        --surface-tint: #EEF2FF;
        --accent: #6366F1;
        --accent-hover: #4F46E5;
        --accent-dim: #C7D2FE;
        --amber: #F59E0B;
        --amber-dim: #FEF3C7;
        --mono: 'Courier New', Courier, monospace;
        --serif: Georgia, 'Times New Roman', serif;
        --sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
        --radius: 12px;
        --radius-sm: 6px;
        --radius-pill: 999px;
        --max: 1160px;
        --col: 680px;
        --shadow-sm: 0 1px 3px rgba(15,23,42,0.06), 0 1px 2px rgba(15,23,42,0.04);
        --shadow: 0 4px 16px rgba(15,23,42,0.08), 0 2px 6px rgba(15,23,42,0.05);
        --shadow-lg: 0 16px 48px rgba(15,23,42,0.12), 0 4px 12px rgba(15,23,42,0.08);
        --transition: 200ms cubic-bezier(0.4,0,0.2,1);
    }

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

    html { scroll-behavior: smooth; }

    body {
        font-family: var(--sans);
        background: var(--paper);
        color: var(--ink);
        line-height: 1.6;
        font-size: 1rem;
    }

    img { display: block; max-width: 100%; }
    a { color: inherit; text-decoration: none; }
    ul, ol { list-style: none; }

    .container {
        width: 100%;
        max-width: var(--max);
        margin-inline: auto;
        padding-inline: 1.5rem;
    }

    /* ══════════════════════════════════════
       READING PROGRESS BAR
    ══════════════════════════════════════ */
    .progress-bar {
        position: fixed;
        top: 0;
        left: 0;
        width: 0%;
        height: 3px;
        background: linear-gradient(90deg, var(--accent), var(--amber));
        z-index: 200;
        transition: width 0.1s linear;
        border-radius: 0 2px 2px 0;
    }

    /* ══════════════════════════════════════
       HEADER
    ══════════════════════════════════════ */
    .site-header {
        position: sticky;
        top: 0;
        z-index: 100;
        background: rgba(255,255,255,0.85);
        backdrop-filter: blur(12px);
        -webkit-backdrop-filter: blur(12px);
        border-bottom: 1px solid var(--paper-mid);
    }

    .header-inner {
        display: flex;
        align-items: center;
        justify-content: space-between;
        height: 68px;
    }

    .logo {
        display: flex;
        align-items: baseline;
        gap: 0.4rem;
    }

    .logo-word {
        font-family: var(--sans);
        font-size: 1.4rem;
        font-weight: 800;
        letter-spacing: -0.04em;
        background: linear-gradient(135deg, var(--accent), var(--amber));
        -webkit-background-clip: text;
        -webkit-text-fill-color: transparent;
        background-clip: text;
    }

    .logo-mark {
        font-family: var(--mono);
        font-size: 0.65rem;
        color: var(--accent);
        text-transform: uppercase;
        letter-spacing: 0.12em;
        align-self: center;
        border: 1px solid var(--accent-dim);
        background: var(--surface-tint);
        padding: 1px 5px;
        border-radius: var(--radius-sm);
    }

    .nav-list {
        display: flex;
        gap: 0.25rem;
        align-items: center;
    }

    .nav-list a {
        font-size: 0.875rem;
        font-weight: 500;
        color: var(--ink-light);
        padding: 0.4rem 0.85rem;
        border-radius: var(--radius-pill);
        transition: color var(--transition), background var(--transition);
    }

    .nav-list a:hover {
        color: var(--ink);
        background: var(--paper-mid);
    }

    .hamburger {
        display: none;
        flex-direction: column;
        gap: 5px;
        background: none;
        border: none;
        cursor: pointer;
        padding: 8px;
        border-radius: var(--radius-sm);
        transition: background var(--transition);
    }

    .hamburger:hover { background: var(--paper-mid); }

    .hamburger span {
        display: block;
        width: 22px;
        height: 2px;
        background: var(--ink);
        border-radius: 2px;
        transition: transform var(--transition), opacity var(--transition);
    }

    .hamburger[aria-expanded="true"] span:nth-child(1) {
        transform: translateY(7px) rotate(45deg);
    }
    .hamburger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
    .hamburger[aria-expanded="true"] span:nth-child(3) {
        transform: translateY(-7px) rotate(-45deg);
    }

    .mobile-nav {
        display: none;
        background: var(--surface);
        border-top: 1px solid var(--paper-mid);
        box-shadow: var(--shadow-lg);
    }

    .mobile-nav.is-open { display: block; }

    .mobile-nav ul {
        display: flex;
        flex-direction: column;
        padding: 1rem 1.5rem 1.5rem;
        gap: 0.25rem;
    }

    .mobile-nav a {
        display: block;
        padding: 0.65rem 1rem;
        font-size: 0.95rem;
        font-weight: 500;
        color: var(--ink-light);
        border-radius: var(--radius-sm);
        transition: color var(--transition), background var(--transition);
    }

    .mobile-nav a:hover {
        color: var(--ink);
        background: var(--paper);
    }

    /* ══════════════════════════════════════
       BREADCRUMB
    ══════════════════════════════════════ */
    .breadcrumb {
        padding: 1rem 0;
        border-bottom: 1px solid var(--paper-mid);
    }

    .breadcrumb-list {
        display: flex;
        align-items: center;
        gap: 0.5rem;
        font-size: 0.8rem;
        color: var(--ink-light);
    }

    .breadcrumb-list a {
        color: var(--ink-light);
        transition: color var(--transition);
    }

    .breadcrumb-list a:hover { color: var(--accent); }

    .breadcrumb-sep { opacity: 0.4; }

    .breadcrumb-current {
        color: var(--ink);
        font-weight: 500;
    }

    /* ══════════════════════════════════════
       ARTICLE HERO
    ══════════════════════════════════════ */
    .article-hero {
        background: linear-gradient(135deg, #0F172A 0%, #1E1B4B 50%, #0F172A 100%);
        color: var(--paper);
        padding: 4.5rem 0 0;
        position: relative;
        overflow: hidden;
    }

    .article-hero::before {
        content: '';
        position: absolute;
        inset: 0;
        background:
            radial-gradient(ellipse 60% 60% at 90% 40%, rgba(99,102,241,0.18) 0%, transparent 65%),
            radial-gradient(ellipse 40% 50% at 5% 90%, rgba(245,158,11,0.08) 0%, transparent 55%);
        pointer-events: none;
    }

    .article-hero::after {
        content: '';
        position: absolute;
        top: 0; left: 0; right: 0;
        height: 1px;
        background: linear-gradient(90deg, transparent, rgba(99,102,241,0.5), rgba(245,158,11,0.3), transparent);
    }

    .article-hero-inner {
        position: relative;
        max-width: var(--col);
    }

    .article-eyebrow {
        display: flex;
        align-items: center;
        gap: 1rem;
        margin-bottom: 1.5rem;
    }

    .article-tag {
        display: inline-flex;
        align-items: center;
        font-family: var(--mono);
        font-size: 0.65rem;
        letter-spacing: 0.12em;
        text-transform: uppercase;
        font-weight: 600;
        color: var(--amber);
        background: rgba(245,158,11,0.12);
        border: 1px solid rgba(245,158,11,0.25);
        padding: 3px 10px;
        border-radius: var(--radius-pill);
    }

    .article-date {
        font-family: var(--mono);
        font-size: 0.72rem;
        color: #64748B;
        letter-spacing: 0.06em;
    }

    .article-title {
        font-family: var(--sans);
        font-size: clamp(1.9rem, 4.5vw, 2.8rem);
        line-height: 1.18;
        font-weight: 800;
        letter-spacing: -0.04em;
        margin-bottom: 1.25rem;
        color: #F8FAFC;
    }

    .article-subtitle {
        font-size: 1.05rem;
        color: #94A3B8;
        line-height: 1.7;
        max-width: 560px;
        margin-bottom: 2.5rem;
    }

    .article-meta-bar {
        display: flex;
        align-items: center;
        gap: 2rem;
        padding: 1.25rem 0;
        border-top: 1px solid rgba(255,255,255,0.08);
    }

    .author-info {
        display: flex;
        align-items: center;
        gap: 0.75rem;
    }

    .author-avatar {
        width: 38px;
        height: 38px;
        border-radius: 50%;
        background: linear-gradient(135deg, var(--accent), var(--accent-hover));
        display: flex;
        align-items: center;
        justify-content: center;
        font-family: var(--sans);
        font-size: 0.95rem;
        font-weight: 800;
        color: #fff;
        flex-shrink: 0;
    }

    .author-name {
        font-size: 0.875rem;
        font-weight: 600;
        color: #F1F5F9;
    }

    .author-role {
        font-size: 0.72rem;
        color: #64748B;
    }

    .meta-stats {
        display: flex;
        gap: 1.5rem;
        margin-left: auto;
    }

    .meta-stat {
        display: flex;
        align-items: center;
        gap: 0.4rem;
        font-family: var(--mono);
        font-size: 0.72rem;
        color: #64748B;
        letter-spacing: 0.04em;
    }

    .meta-stat svg { flex-shrink: 0; }

    /* Cover image strip */
    .cover-strip {
        width: 100%;
        height: 420px;
        background: linear-gradient(135deg, #1E1B4B 0%, #0F172A 60%, #1a1030 100%);
        display: flex;
        align-items: center;
        justify-content: center;
        margin-top: 2.5rem;
        position: relative;
        overflow: hidden;
    }

    .cover-image {
        width: 100%;
        height: 100%;
        object-fit: cover;
        opacity: 0.9;
    }

    .cover-strip::after {
        content: '';
        position: absolute;
        bottom: 0;
        left: 0;
        right: 0;
        height: 80px;
        background: linear-gradient(to bottom, transparent, var(--paper));
        pointer-events: none;
    }

    .cover-illustration {
        position: relative;
        z-index: 1;
        text-align: center;
    }

    .cover-illustration svg { margin: 0 auto 1rem; }

    .cover-caption {
        font-family: var(--mono);
        font-size: 0.68rem;
        color: rgba(255,255,255,0.3);
        letter-spacing: 0.14em;
        text-transform: uppercase;
    }

    /* ══════════════════════════════════════
       ARTICLE LAYOUT
    ══════════════════════════════════════ */
    .article-layout {
        display: grid;
        grid-template-columns: 1fr 256px;
        gap: 4rem;
        align-items: start;
        padding: 4rem 0 5rem;
    }

    /* ── Article Body ── */
    .article-body {
        max-width: var(--col);
    }

    /* Drop cap */
    .article-content > p:first-child::first-letter {
        font-family: var(--sans);
        font-size: 4rem;
        font-weight: 800;
        line-height: 0.8;
        float: left;
        margin-right: 0.12em;
        margin-top: 0.1em;
        color: var(--accent);
    }

    .article-content p {
        font-size: 1.08rem;
        line-height: 1.82;
        color: var(--ink);
        margin-bottom: 1.6rem;
    }

    .article-content h2 {
        font-family: var(--sans);
        font-size: 1.55rem;
        font-weight: 800;
        letter-spacing: -0.03em;
        line-height: 1.25;
        margin: 2.75rem 0 1rem;
        color: var(--ink);
    }

    .article-content h3 {
        font-family: var(--sans);
        font-size: 1.15rem;
        font-weight: 700;
        letter-spacing: -0.02em;
        margin: 2rem 0 0.75rem;
        color: var(--ink);
    }

    .article-content blockquote {
        margin: 2.5rem 0;
        padding: 1.75rem 2rem;
        border-left: 3px solid var(--accent);
        background: var(--surface-tint);
        border-radius: 0 var(--radius) var(--radius) 0;
        box-shadow: var(--shadow-sm);
    }

    .article-content blockquote p {
        font-family: var(--serif);
        font-size: 1.15rem;
        font-style: italic;
        line-height: 1.65;
        color: var(--ink);
        margin-bottom: 0.5rem;
    }

    .article-content blockquote cite {
        font-size: 0.78rem;
        font-family: var(--mono);
        letter-spacing: 0.06em;
        color: var(--ink-light);
        font-style: normal;
    }

    .article-content ul {
        list-style: none;
        margin-bottom: 1.6rem;
    }

    .article-content ul li {
        padding: 0.35rem 0 0.35rem 1.5rem;
        position: relative;
        font-size: 1.05rem;
        line-height: 1.72;
        color: var(--ink);
    }

    .article-content ul li::before {
        content: '';
        position: absolute;
        left: 0;
        top: 0.75em;
        width: 6px;
        height: 6px;
        border-radius: 50%;
        background: var(--accent);
    }

    .article-content .callout {
        background: var(--surface-tint);
        border: 1px solid var(--accent-dim);
        border-radius: var(--radius);
        padding: 1.4rem 1.6rem;
        margin: 2rem 0;
        font-size: 0.95rem;
        line-height: 1.7;
        box-shadow: var(--shadow-sm);
    }

    .article-content .callout strong {
        display: block;
        font-family: var(--mono);
        font-size: 0.65rem;
        letter-spacing: 0.14em;
        text-transform: uppercase;
        color: var(--accent);
        font-weight: 700;
        margin-bottom: 0.5rem;
    }

    /* Article divider */
    .article-divider {
        text-align: center;
        margin: 2.5rem 0;
        color: var(--accent-dim);
        font-size: 1.2rem;
        letter-spacing: 0.6em;
    }

    /* Tags & sharing */
    .article-footer {
        margin-top: 3rem;
        padding-top: 2rem;
        border-top: 1px solid var(--paper-mid);
    }

    .article-tags {
        display: flex;
        flex-wrap: wrap;
        gap: 0.5rem;
        margin-bottom: 2rem;
        align-items: center;
    }

    .tags-label {
        font-family: var(--mono);
        font-size: 0.68rem;
        letter-spacing: 0.1em;
        text-transform: uppercase;
        color: var(--ink-light);
        font-weight: 600;
    }

    .tag-pill {
        font-size: 0.78rem;
        padding: 4px 14px;
        border: 1px solid var(--paper-mid);
        border-radius: var(--radius-pill);
        color: var(--ink-light);
        background: var(--surface);
        font-weight: 500;
        transition: border-color var(--transition), color var(--transition), background var(--transition);
    }

    .tag-pill:hover {
        border-color: var(--accent-dim);
        color: var(--accent);
        background: var(--surface-tint);
    }

    .share-bar {
        display: flex;
        align-items: center;
        gap: 0.75rem;
    }

    .share-label {
        font-family: var(--mono);
        font-size: 0.68rem;
        letter-spacing: 0.1em;
        text-transform: uppercase;
        color: var(--ink-light);
        font-weight: 600;
    }

    .share-btn {
        display: inline-flex;
        align-items: center;
        gap: 0.4rem;
        padding: 0.5rem 1rem;
        border: 1px solid var(--paper-mid);
        border-radius: var(--radius-pill);
        font-size: 0.8rem;
        font-weight: 600;
        color: var(--ink);
        background: var(--surface);
        cursor: pointer;
        font-family: var(--sans);
        box-shadow: var(--shadow-sm);
        transition: border-color var(--transition), background var(--transition), box-shadow var(--transition);
    }

    .share-btn:hover {
        border-color: var(--accent-dim);
        background: var(--surface-tint);
        box-shadow: var(--shadow);
    }

    .share-btn.copied {
        border-color: #10B981;
        color: #10B981;
        background: #F0FDF4;
    }

    /* ── Author card ── */
    .author-card {
        margin-top: 3rem;
        padding: 2rem;
        background: linear-gradient(135deg, var(--surface-tint), var(--surface));
        border: 1px solid var(--accent-dim);
        border-radius: var(--radius);
        display: flex;
        gap: 1.25rem;
        align-items: flex-start;
        box-shadow: var(--shadow-sm);
    }

    .author-card-avatar {
        width: 56px;
        height: 56px;
        border-radius: 50%;
        background: linear-gradient(135deg, var(--accent), var(--accent-hover));
        display: flex;
        align-items: center;
        justify-content: center;
        font-family: var(--sans);
        font-size: 1.3rem;
        font-weight: 800;
        color: #fff;
        flex-shrink: 0;
        box-shadow: 0 4px 12px rgba(99,102,241,0.3);
    }

    .author-card-name {
        font-family: var(--sans);
        font-size: 1rem;
        font-weight: 700;
        margin-bottom: 0.15rem;
        letter-spacing: -0.02em;
    }

    .author-card-title {
        font-family: var(--mono);
        font-size: 0.65rem;
        letter-spacing: 0.12em;
        text-transform: uppercase;
        color: var(--accent);
        font-weight: 600;
        margin-bottom: 0.6rem;
    }

    .author-card-bio {
        font-size: 0.875rem;
        color: var(--ink-light);
        line-height: 1.65;
    }

    /* ── Sticky TOC Sidebar ── */
    .article-sidebar {
        position: sticky;
        top: 88px;
    }

    .sidebar-block {
        background: var(--surface);
        border: 1px solid var(--paper-mid);
        border-radius: var(--radius);
        padding: 1.4rem;
        margin-bottom: 1.25rem;
        box-shadow: var(--shadow-sm);
    }

    .sidebar-block:last-child { margin-bottom: 0; }

    .sidebar-title {
        font-family: var(--mono);
        font-size: 0.62rem;
        letter-spacing: 0.16em;
        text-transform: uppercase;
        color: var(--accent);
        font-weight: 700;
        margin-bottom: 1rem;
        display: flex;
        align-items: center;
        gap: 0.5rem;
    }

    .sidebar-title::after {
        content: '';
        flex: 1;
        height: 1px;
        background: linear-gradient(90deg, var(--accent-dim), transparent);
    }

    .toc-list {
        display: flex;
        flex-direction: column;
        gap: 0.1rem;
    }

    .toc-list a {
        display: block;
        padding: 0.4rem 0.75rem;
        font-size: 0.83rem;
        color: var(--ink-light);
        border-left: 2px solid transparent;
        border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
        transition: color var(--transition), border-color var(--transition), background var(--transition);
        line-height: 1.4;
        font-weight: 500;
    }

    .toc-list a:hover,
    .toc-list a.active {
        color: var(--accent);
        border-left-color: var(--accent);
        background: var(--surface-tint);
    }

    /* Related mini posts */
    .related-mini {
        display: flex;
        flex-direction: column;
        gap: 1rem;
    }

    .related-mini-item {
        display: flex;
        flex-direction: column;
        gap: 0.2rem;
        padding-bottom: 1rem;
        border-bottom: 1px solid var(--paper-mid);
    }

    .related-mini-item:last-child {
        border-bottom: none;
        padding-bottom: 0;
    }

    .related-mini-tag {
        font-family: var(--mono);
        font-size: 0.62rem;
        letter-spacing: 0.1em;
        text-transform: uppercase;
        color: var(--amber);
        font-weight: 600;
    }

    .related-mini-title {
        font-size: 0.875rem;
        font-weight: 600;
        line-height: 1.35;
        color: var(--ink);
        transition: color var(--transition);
    }

    .related-mini-title:hover { color: var(--accent); }

    .related-mini-date {
        font-size: 0.72rem;
        color: var(--ink-light);
    }

    /* ══════════════════════════════════════
       MORE POSTS (bottom)
    ══════════════════════════════════════ */
    .more-posts {
        padding: 4rem 0 5rem;
        border-top: 1px solid var(--paper-mid);
    }

    .section-label {
        font-family: var(--mono);
        font-size: 0.68rem;
        letter-spacing: 0.18em;
        text-transform: uppercase;
        color: var(--accent);
        font-weight: 700;
        margin-bottom: 2rem;
        display: flex;
        align-items: center;
        gap: 0.75rem;
    }

    .section-label::after {
        content: '';
        flex: 1;
        height: 1px;
        background: linear-gradient(90deg, var(--accent-dim), transparent);
    }

    .more-grid {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 1.5rem;
    }

    .more-card {
        display: flex;
        flex-direction: column;
        gap: 0.75rem;
        padding: 1.5rem;
        background: var(--surface);
        border: 1px solid var(--paper-mid);
        border-radius: var(--radius);
        box-shadow: var(--shadow-sm);
        transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
    }

    .more-card:hover {
        box-shadow: var(--shadow);
        transform: translateY(-3px);
        border-color: var(--accent-dim);
    }

    .more-card-thumb {
        width: 100%;
        height: 110px;
        background: var(--paper);
        border-radius: var(--radius-sm);
        overflow: hidden;
        display: flex;
        align-items: center;
        justify-content: center;
        margin-bottom: 0.25rem;
        border: 1px solid var(--paper-mid);
    }

    .more-card-thumb svg { opacity: 0.2; }

    .more-card-tag {
        font-family: var(--mono);
        font-size: 0.62rem;
        letter-spacing: 0.1em;
        text-transform: uppercase;
        color: var(--amber);
        font-weight: 600;
    }

    .more-card-title {
        font-family: var(--sans);
        font-size: 1rem;
        font-weight: 700;
        line-height: 1.35;
        letter-spacing: -0.02em;
        color: var(--ink);
        transition: color var(--transition);
    }

    .more-card:hover .more-card-title { color: var(--accent); }

    .more-card-excerpt {
        font-size: 0.83rem;
        color: var(--ink-light);
        line-height: 1.6;
        flex: 1;
    }

    .more-card-date {
        font-family: var(--mono);
        font-size: 0.68rem;
        color: var(--ink-light);
        margin-top: auto;
    }

    /* ══════════════════════════════════════
       FOOTER
    ══════════════════════════════════════ */
    .site-footer {
        background: var(--ink);
        color: #94A3B8;
        padding: 3.5rem 0 2rem;
    }

    .footer-inner {
        display: grid;
        grid-template-columns: 1fr auto;
        gap: 2rem;
        align-items: end;
        padding-bottom: 2rem;
        border-bottom: 1px solid rgba(255,255,255,0.07);
        margin-bottom: 1.5rem;
    }

    .footer-brand .logo-word {
        background: linear-gradient(135deg, var(--accent), var(--amber));
        -webkit-background-clip: text;
        -webkit-text-fill-color: transparent;
        background-clip: text;
    }

    .footer-brand p {
        font-size: 0.85rem;
        max-width: 300px;
        line-height: 1.65;
        margin-top: 0.75rem;
        color: #475569;
    }

    .social-links {
        display: flex;
        gap: 0.6rem;
        align-items: center;
    }

    .social-link {
        width: 38px;
        height: 38px;
        border: 1px solid rgba(255,255,255,0.1);
        border-radius: 50%;
        display: flex;
        align-items: center;
        justify-content: center;
        color: #94A3B8;
        transition: border-color var(--transition), color var(--transition), background var(--transition);
    }

    .social-link:hover {
        border-color: var(--accent);
        color: #fff;
        background: rgba(99,102,241,0.15);
    }

    .footer-bottom {
        display: flex;
        justify-content: space-between;
        align-items: center;
        font-size: 0.8rem;
        color: #475569;
    }

    .footer-nav {
        display: flex;
        gap: 1.5rem;
    }

    .footer-nav a {
        color: #475569;
        transition: color var(--transition);
    }

    .footer-nav a:hover { color: #94A3B8; }

    /* ══════════════════════════════════════
       RESPONSIVE
    ══════════════════════════════════════ */
    @media (max-width: 900px) {
        .article-layout {
            grid-template-columns: 1fr;
            gap: 2rem;
        }

        .article-sidebar { position: static; }

        .hamburger { display: flex; }

        .main-nav { display: none; }

        .more-grid { grid-template-columns: repeat(2, 1fr); }

        .meta-stats { display: none; }
    }

    @media (max-width: 600px) {
        .more-grid { grid-template-columns: 1fr; }

        .cover-strip { height: 260px; }

        .article-title { font-size: 1.8rem; }

        .footer-inner { grid-template-columns: 1fr; }

        .footer-bottom {
            flex-direction: column;
            gap: 1rem;
            text-align: center;
        }
    }

    @media (prefers-reduced-motion: reduce) {
        *, *::before, *::after {
            transition: none !important;
            animation: none !important;
        }
    }