/* ── reset & tokens ── */
    :root {
        --bg:        #0F1A1B;
        --card:      #162122;
        --card-border: rgba(64,212,224,.10);
        --cyan:      #40D4E0;
        --gold:      #FFD700;
        --green:     #4ADE80;
        --text:      #DDE6E8;
        --muted:     #7A9EA2;
        --radius:    18px;
    }
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; }
    body {
        background: var(--bg);
        color: var(--text);
        font-family: 'Inter', system-ui, -apple-system, sans-serif;
        -webkit-font-smoothing: antialiased;
        font-size: 16px;
        line-height: 1.7;
    }
    /* ── page wrapper ── */
    .blog-wrapper {
        max-width: 860px;
        margin: 0 auto;
        padding: 40px 20px 96px;
    }
    /* ── breadcrumb ── */
    .blog-breadcrumb {
        font-size: 12px;
        color: var(--muted);
        margin-bottom: 20px;
        display: flex;
        align-items: center;
        gap: 6px;
    }
    .blog-breadcrumb a { color: var(--cyan); text-decoration: none; }
    .blog-breadcrumb a:hover { text-decoration: underline; }
    /* ── category badge ── */
    .category-badge {
        display: inline-flex;
        align-items: center;
        gap: 6px;
        font-size: 11px;
        font-weight: 800;
        letter-spacing: .09em;
        text-transform: uppercase;
        padding: 5px 13px;
        border-radius: 100px;
        border: 1.5px solid currentColor;
        border-color: inherit;
        margin-bottom: 20px;
        transition: opacity .15s;
    }
    /* ── animated glow keyframe ── */
    @keyframes pulse-glow {
        0%,100% { opacity: .55; transform: scale(1); }
        50%      { opacity: 1;   transform: scale(1.08); }
    }
    /* ── hero (glassmorphism) ── */
    .blog-hero {
        background: linear-gradient(145deg,
            rgba(22,33,34,.92) 0%,
            rgba(15,26,27,.96) 60%,
            rgba(64,212,224,.06) 100%);
        backdrop-filter: blur(18px) saturate(1.4);
        -webkit-backdrop-filter: blur(18px) saturate(1.4);
        border: 1px solid rgba(64,212,224,.18);
        border-radius: var(--radius);
        padding: 56px 52px 48px;
        text-align: center;
        margin-bottom: 24px;
        position: relative;
        overflow: hidden;
        box-shadow: 0 0 0 1px rgba(64,212,224,.05),
                    0 24px 64px rgba(0,0,0,.45);
    }
    .blog-hero::before {
        content: "";
        position: absolute;
        width: 520px; height: 320px;
        left: 50%; top: -80px;
        transform: translateX(-50%);
        background: radial-gradient(ellipse at center,
            rgba(64,212,224,.14) 0%,
            rgba(64,212,224,.04) 50%,
            transparent 70%);
        pointer-events: none;
        animation: pulse-glow 4s ease-in-out infinite;
        border-radius: 50%;
    }
    .blog-hero::after {
        content: "";
        position: absolute;
        bottom: 0; left: 10%; right: 10%; height: 1px;
        background: linear-gradient(90deg, transparent, rgba(64,212,224,.35), transparent);
        pointer-events: none;
    }
    .blog-hero h1 {
        font-size: clamp(24px, 5vw, 42px);
        font-weight: 800;
        letter-spacing: -.025em;
        line-height: 1.2;
        color: #fff;
        margin-bottom: 18px;
        position: relative;
    }
    .blog-meta {
        display: flex;
        align-items: center;
        justify-content: center;
        flex-wrap: wrap;
        gap: 8px;
        font-size: 12.5px;
        color: var(--muted);
        position: relative;
    }
    .blog-meta-dot {
        width: 3px; height: 3px;
        border-radius: 50%;
        background: var(--muted);
        display: inline-block;
        flex-shrink: 0;
    }
    /* ── hero image (above title) ── */
    .blog-hero-img {
        width: 100%;
        height: auto;
        aspect-ratio: 2/1;
        object-fit: cover;
        border-radius: 10px;
        margin-bottom: 24px;
        display: block;
        position: relative;
        background: var(--card);
    }
    /* ── table of contents ── */
    .toc-container {
        background: var(--card);
        border: 1px solid rgba(64,212,224,.15);
        border-radius: 12px;
        padding: 16px 20px;
        margin-bottom: 24px;
        position: sticky;
        top: 20px;
        z-index: 10;
    }
    .toc-toggle {
        background: none; border: none; color: var(--text);
        font-size: 15px; font-weight: 700; width: 100%;
        display: flex; justify-content: space-between; align-items: center;
        cursor: pointer; padding: 0; font-family: inherit;
    }
    .toc-icon { transition: transform 0.3s ease; font-size: 12px; color: var(--cyan); }
    .toc-toggle[aria-expanded="true"] .toc-icon { transform: rotate(180deg); }
    .toc-list {
        list-style: none; padding: 0; margin: 12px 0 0 0;
        overflow: hidden; transition: max-height 0.35s ease; max-height: 500px;
    }
    .toc-list.hidden { max-height: 0; margin: 0; }
    .toc-list li { margin-bottom: 8px; border-left: 2px solid transparent; transition: border-color 0.2s; }
    .toc-list li:hover { border-left-color: var(--cyan); }
    .toc-list a { color: var(--muted); text-decoration: none; font-size: 14px; display: block; padding: 4px 0 4px 12px; transition: color 0.2s; }
    .toc-list a:hover { color: var(--cyan); }
    /* ── premium reading experience ── */
    .blog-content {
        background: var(--card);
        border: 1px solid rgba(255,255,255,.05);
        padding: 48px 52px;
        border-radius: var(--radius);
        line-height: 1.9;
        font-size: 17.5px;
        margin-bottom: 24px;
    }
    .blog-content h2 {
        color: var(--cyan);
        font-size: 24px;
        font-weight: 800;
        margin: 2.8rem 0 1rem;
        letter-spacing: -.02em;
        padding-bottom: 0.5rem;
        border-bottom: 1px solid rgba(64,212,224,.1);
        scroll-margin-top: 80px;
    }
    .blog-content h3 {
        color: var(--gold);
        font-size: 19px;
        font-weight: 700;
        margin: 2rem 0 0.8rem;
    }
    .blog-content h4 {
        color: var(--green);
        font-size: 16.5px;
        font-weight: 700;
        margin: 1.5rem 0 0.5rem;
    }
    .blog-content p  { color: #C2D5D8; margin: 0 0 1.5rem; }
    .blog-content ul { padding-left: 0; list-style: none; margin: 0 0 1.5rem; }
    .blog-content ol { padding-left: 1.5rem; margin: 0 0 1.5rem; }
    .blog-content li { position: relative; padding: .5rem 0 .5rem 1.6rem; color: #C2D5D8; }
    .blog-content ul li::before {
        content: "";
        position: absolute; left: 0; top: 1rem;
        width: 6px; height: 6px;
        border-radius: 50%;
        background: var(--cyan);
        box-shadow: 0 0 6px rgba(64,212,224,.4);
    }
    .blog-content blockquote {
        border-left: 4px solid var(--cyan);
        margin: 2rem 0;
        padding: 1.2rem 1.5rem;
        background: linear-gradient(90deg, rgba(64,212,224,.06) 0%, transparent 100%);
        border-radius: 0 12px 12px 0;
        font-style: italic;
    }
    .blog-content blockquote p { color: #8FCCD2; margin: 0; }
    .blog-content strong { color: #fff; font-weight: 700; }
    .blog-content a  { color: var(--cyan); text-underline-offset: 4px; text-decoration-thickness: 1px; }
    /* ── internal link ── */
    .internal-link {
        color: var(--cyan);
        text-decoration: underline;
        text-decoration-color: rgba(64, 212, 224, 0.4);
        text-decoration-thickness: 1px;
        text-underline-offset: 3px;
        transition: color .15s, text-decoration-color .15s;
        font-weight: inherit;
    }
    .internal-link:hover {
        color: #fff;
        text-decoration-color: #fff;
    }
    .blog-content hr { border: none; border-top: 1px solid rgba(255,255,255,.07); margin: 3rem 0; }
    .blog-content code {
        font-family: 'JetBrains Mono', 'Fira Code', monospace;
        font-size: .85em;
        background: rgba(64,212,224,.1);
        color: var(--cyan);
        padding: .2em .5em;
        border-radius: 6px;
        border: 1px solid rgba(64,212,224,.15);
    }
    .blog-content pre {
        background: rgba(0,0,0,.4);
        border: 1px solid rgba(64,212,224,.2);
        border-radius: 12px;
        padding: 1.2rem 1.5rem;
        overflow-x: auto;
        margin: 0 0 1.5rem;
    }
    .blog-content pre code { background: none; border: none; padding: 0; font-size: .9em; color: var(--cyan); }
    .blog-content table { width: 100%; border-collapse: collapse; font-size: 15px; margin: 0 0 1.5rem; border-radius: 10px; overflow: hidden; border: 1px solid rgba(64,212,224,.15); }
    .blog-content th { background: rgba(64,212,224,.12); color: var(--cyan); padding: 12px 16px; text-align: left; font-size: 12px; letter-spacing: .06em; text-transform: uppercase; border-bottom: 2px solid rgba(64,212,224,.2); }
    .blog-content td { padding: 12px 16px; color: #C2D5D8; border-bottom: 1px solid rgba(255,255,255,.05); }
    .blog-content tr:last-child td { border-bottom: none; }
    .blog-content tr:hover td { background: rgba(64,212,224,.03); }
    /* Note/Tip Boxes */
    .blog-content p > strong:only-child { display: inline-block; margin-bottom: 0.5rem; }
    .note-box, .tip-box {
        padding: 1.2rem 1.5rem;
        border-radius: 10px;
        margin: 1.5rem 0;
        border-left: 4px solid;
    }
    .note-box { background: rgba(96, 165, 250, .08); border-color: #60A5FA; color: #93C5FD; }
    .tip-box { background: rgba(74, 222, 128, .08); border-color: #4ADE80; color: #86EFAC; }
    /* ── CTA card ── */
    .blog-cta {
        background: linear-gradient(135deg, var(--card) 0%, rgba(64,212,224,.06) 100%);
        border: 1px solid rgba(64,212,224,.22);
        padding: 44px 48px;
        border-radius: var(--radius);
        text-align: center;
    }
    .blog-cta h2 { color: #fff; font-size: 24px; font-weight: 800; margin: 0 0 12px; }
    .blog-cta p  { color: var(--muted); margin: 0 0 28px; font-size: 16px; line-height: 1.6; }
    .blog-cta-btn {
        display: inline-block;
        background: var(--cyan);
        color: #0B1718;
        padding: 16px 36px;
        border-radius: 12px;
        text-decoration: none;
        font-weight: 800;
        font-size: 16px;
        letter-spacing: .01em;
        transition: transform .2s, box-shadow .2s;
        box-shadow: 0 4px 15px rgba(64, 212, 224, 0.2);
    }
    .blog-cta-btn:hover { transform: translateY(-2px); box-shadow: 0 8px 25px rgba(64, 212, 224, 0.3); }
    /* ── blog card (Redesign) ── */
    .blog-card {
        display: flex;
        flex-direction: column;
        background: var(--card);
        border: 1px solid rgba(255,255,255,.08);
        border-radius: 16px;
        text-decoration: none;
        transition: transform .25s cubic-bezier(.4,0,.2,1), box-shadow .25s cubic-bezier(.4,0,.2,1), border-color .25s;
        position: relative;
        overflow: hidden;
    }
    .blog-card::after {
        content: '';
        position: absolute;
        inset: 0;
        border-radius: 16px;
        padding: 1px;
        background: linear-gradient(135deg, var(--glow-color, transparent), transparent 60%);
        -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
        -webkit-mask-composite: xor;
        mask-composite: exclude;
        pointer-events: none;
        opacity: 0;
        transition: opacity .3s;
    }
    .blog-card:hover::after { opacity: 1; }
    .blog-card:hover {
        transform: translateY(-6px);
        box-shadow: 0 16px 40px rgba(0,0,0,.4), 0 0 20px var(--glow-color, transparent);
        border-color: transparent;
    }
    .blog-card-thumb-wrap { width: 100%; height: 180px; overflow: hidden; background: var(--bg); }
    .blog-card-thumb { width: 100%; height: 100%; object-fit: cover; transition: transform .4s; }
    .blog-card:hover .blog-card-thumb { transform: scale(1.05); }
    .blog-card-body { padding: 20px 22px 24px; display: flex; flex-direction: column; flex: 1; }
    .blog-card-badge { 
        display: inline-flex; align-items: center; gap: 5px;
        font-size: 10px; font-weight: 800; letter-spacing: .09em;
        text-transform: uppercase; padding: 4px 10px; border-radius: 100px;
        border: 1.5px solid currentColor; margin-bottom: 12px; align-self: flex-start;
    }
    .blog-card h3 { 
        color: #fff; font-size: 17px; font-weight: 700;
        line-height: 1.4; margin: 0 0 10px; 
        display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
    }
    .blog-card-exc { 
        color: var(--muted); font-size: 14px; line-height: 1.6;
        display: -webkit-box; -webkit-line-clamp: 2;
        -webkit-box-orient: vertical; overflow: hidden; margin-bottom: 16px; flex: 1;
    }
    .blog-card-meta { display: flex; align-items: center; gap: 8px; font-size: 12px; color: var(--muted); margin-bottom: 16px; }
    .blog-card-dot { width: 3px; height: 3px; border-radius: 50%; background: var(--muted); display: inline-block; }
    .blog-card-btn {
        align-self: flex-start;
        font-size: 13px; font-weight: 700;
        padding: 8px 16px; border-radius: 8px;
        transition: filter .2s, transform .2s;
    }
    .blog-card:hover .blog-card-btn { filter: brightness(1.2); transform: translateX(4px); }
    /* ── related articles (Redesign) ── */
    .blog-related { margin-top: 32px; }
    .rel-heading { color: var(--muted); font-size: 11px; font-weight: 800; letter-spacing: .1em; text-transform: uppercase; margin-bottom: 16px; }
    .rel-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px,1fr)); gap: 16px; }
    .rel-card { 
        display: flex; flex-direction: column;
        background: var(--card); border: 1px solid rgba(255,255,255,.08);
        border-radius: 14px; text-decoration: none; overflow: hidden;
        transition: transform .25s cubic-bezier(.4,0,.2,1), box-shadow .25s, border-color .25s;
    }
    .rel-card:hover { 
        transform: translateY(-4px);
        box-shadow: 0 12px 30px rgba(0,0,0,.3), 0 0 15px var(--glow-color, transparent);
        border-color: transparent;
    }
    .rel-card-thumb { width: 100%; height: 120px; object-fit: cover; display: block; background: var(--bg); }
    .rel-card-body { padding: 16px; display: flex; flex-direction: column; gap: 8px; flex: 1; }
    .rel-card-badge { 
        display: inline-flex; align-self: flex-start;
        font-size: 9px; font-weight: 800; letter-spacing: .08em;
        text-transform: uppercase; padding: 3px 8px; border-radius: 100px;
        border: 1px solid currentColor;
    }
    .rel-card strong { color: #fff; font-size: 14px; line-height: 1.4; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
    .rel-exc { color: var(--muted); font-size: 12.5px; line-height: 1.5; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
    /* ── responsive ── */
    @media (max-width: 600px) {
        body { font-size: 15px; line-height: 1.6; }
        .blog-hero    { padding: 24px 18px 20px; }
        .blog-hero-img { aspect-ratio: 16/9; border-radius: 8px; margin-bottom: 18px; }
        .blog-content { padding: 28px 20px; font-size: 16px; line-height: 1.75; }
        .blog-content h2 { font-size: 20px; margin-top: 2rem; }
        .blog-content h3 { font-size: 17px; }
        .blog-cta     { padding: 28px 22px; }
        .toc-container { position: static; }
        .toc-list { max-height: 0; margin: 0; }
        .blog-card-thumb-wrap { height: 160px; }
        .rel-card-thumb { height: 100px; }
    }