/* =========================================================
   Bukkii Blog v3 — article + index + cover styles
   Chỉ load ở trang bài viết + index blog.
   Font: GT Planar (khai báo trong site-v2.css).
   ========================================================= */

:root {
  --bk-blue: #1c17ff;  --bk-blue-soft: #eceaff;  --bk-blue-dark: #120fb3;
  --bk-mint: #8ee8a6;  --bk-mint-soft: #e3f9ea;  --bk-mint-dark: #0b5c2b;
  --bk-coral: #ff6b4a; --bk-coral-soft: #ffe9e3; --bk-coral-dark: #8a2a12;
  --bk-sun: #ffc53d;   --bk-sun-soft: #fff4d6;   --bk-sun-dark: #6b4a00;
  --bk-sky: #3db8ff;   --bk-sky-soft: #e2f4ff;   --bk-sky-dark: #0a4a73;
  --bk-grape: #6d3ff0; --bk-grape-soft: #f0e9ff; --bk-grape-dark: #4a1d96;
  --bk-pink: #ff5fa2;  --bk-pink-soft: #ffe6f1;  --bk-pink-dark: #8a1650;
  --bk-ink: #0b0b2b;   --bk-ink-soft: #f4f5ff;
  --bk-text: #2b2d4a;  --bk-muted: #565875;  --bk-faint: #8a8ca8;
  --bk-line: #e4e5f2;  --bk-line-strong: #d8daf0;
  --bk-font: "GT Planar", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --bk-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --bk-gutter: clamp(16px, 4vw, 32px);
  --bk-max: 1200px;
}

/* ---------- Tone utilities: đặt --tn / --tn-soft / --tn-dark ---------- */
.t-blue  { --tn: var(--bk-blue);  --tn-soft: var(--bk-blue-soft);  --tn-dark: var(--bk-blue-dark); }
.t-mint  { --tn: var(--bk-mint);  --tn-soft: var(--bk-mint-soft);  --tn-dark: var(--bk-mint-dark); }
.t-coral { --tn: var(--bk-coral); --tn-soft: var(--bk-coral-soft); --tn-dark: var(--bk-coral-dark); }
.t-sun   { --tn: var(--bk-sun);   --tn-soft: var(--bk-sun-soft);   --tn-dark: var(--bk-sun-dark); }
.t-sky   { --tn: var(--bk-sky);   --tn-soft: var(--bk-sky-soft);   --tn-dark: var(--bk-sky-dark); }
.t-grape { --tn: var(--bk-grape); --tn-soft: var(--bk-grape-soft); --tn-dark: var(--bk-grape-dark); }
.t-pink  { --tn: var(--bk-pink);  --tn-soft: var(--bk-pink-soft);  --tn-dark: var(--bk-pink-dark); }
.t-ink   { --tn: var(--bk-ink);   --tn-soft: var(--bk-ink-soft);   --tn-dark: var(--bk-ink); }

/* ---------- Base ---------- */
.bk-page { font-family: var(--bk-font); color: var(--bk-ink); background: #fff; -webkit-font-smoothing: antialiased; }
.bk-page *, .bk-page *::before, .bk-page *::after { box-sizing: border-box; }
.bk-page a { color: var(--bk-blue); }
.bk-page a:hover { color: var(--bk-blue-dark); }
.bk-page :is(a, button, summary, input):focus-visible { outline: 2px solid var(--bk-blue); outline-offset: 2px; border-radius: 6px; }
.bk-wrap { max-width: var(--bk-max); margin: 0 auto; padding-inline: var(--bk-gutter); }
.bk-ico { width: 1em; height: 1em; flex: none; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

/* ---------- Hero ---------- */
.bk-hero { background: var(--bk-ink-soft); border-bottom: 1px solid var(--bk-line); }
.bk-hero__inner { display: flex; flex-wrap: wrap; align-items: center; gap: clamp(28px, 4vw, 56px); padding-block: clamp(28px, 5vw, 64px); }
.bk-hero__text { flex: 1 1 460px; min-width: 0; display: flex; flex-direction: column; gap: 20px; }
.bk-hero__media { flex: 1 1 420px; min-width: 0; border-radius: 20px; overflow: hidden; box-shadow: 0 24px 60px rgba(28, 23, 255, .18); }
.bk-crumbs ol { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 8px; font-size: 14px; color: var(--bk-muted); }
.bk-crumbs a { color: var(--bk-muted); }
.bk-crumbs [aria-current] { color: var(--bk-ink); }
.bk-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.bk-chip { font-size: 13px; font-weight: 700; padding: 5px 12px; border-radius: 99px; background: var(--tn-soft); color: var(--tn-dark); border: 1px solid color-mix(in srgb, var(--tn) 30%, transparent); }
.bk-chip--solid { background: var(--bk-blue); color: #fff; border-color: var(--bk-blue); }
.bk-h1 { margin: 0; font-size: clamp(30px, 4.3vw, 52px); line-height: 1.12; font-weight: 800; letter-spacing: -.03em; text-wrap: balance; }
.bk-lede { margin: 0; max-width: 600px; font-size: clamp(17px, 1.6vw, 20px); line-height: 1.6; color: var(--bk-text); }
.bk-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 12px 20px; font-size: 14px; color: var(--bk-muted); }
.bk-meta > span { display: inline-flex; align-items: center; gap: 6px; }
.bk-meta .bk-ico { font-size: 16px; }
.bk-author { color: var(--bk-ink); font-weight: 600; gap: 10px !important; }
.bk-avatar { width: 36px; height: 36px; border-radius: 50%; background: var(--bk-blue); color: #fff; display: inline-flex; align-items: center; justify-content: center; }
.bk-langs { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; font-size: 14px; color: var(--bk-muted); }
.bk-lang { color: var(--bk-ink) !important; text-decoration: none; font-weight: 600; padding: 6px 12px; border: 1px solid var(--bk-line-strong); border-radius: 99px; background: #fff; }

/* ---------- Layout: TOC + article ---------- */
.bk-layout { display: flex; flex-wrap: wrap; align-items: flex-start; gap: 56px; padding-block: clamp(28px, 5vw, 64px) 32px; }
.bk-toc { flex: 0 0 240px; position: sticky; top: calc(var(--nav-h, 64px) + 24px); display: flex; flex-direction: column; gap: 24px; }
.bk-toc__title { font-size: 12px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--bk-muted); margin-bottom: 12px; }
.bk-toc ol { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 2px; font-size: 15px; line-height: 1.4; }
.bk-toc ol a { display: block; padding: 7px 0 7px 14px; color: var(--bk-text); text-decoration: none; border-left: 2px solid var(--bk-line); }
.bk-toc ol a.is-active { color: var(--bk-blue); border-left-color: var(--bk-blue); font-weight: 600; }
.bk-toc-cta { background: var(--bk-blue); color: #fff; border-radius: 16px; padding: 20px; display: flex; flex-direction: column; gap: 10px; }
.bk-toc-cta__kicker { font-size: 13px; font-weight: 700; color: var(--bk-mint); }
.bk-toc-cta__title { font-size: 18px; font-weight: 700; line-height: 1.35; }
.bk-toc-cta .bk-btn { margin-top: 4px; }
.bk-toc-cta a:not(.bk-btn) { color: #fff; font-size: 14px; text-align: center; }

.bk-toc-m { display: none; border: 1px solid var(--bk-line); border-radius: 14px; margin-bottom: 28px; }
.bk-toc-m summary { list-style: none; cursor: pointer; display: flex; align-items: center; justify-content: space-between; padding: 14px 18px; min-height: 44px; font-size: 16px; font-weight: 700; color: var(--bk-ink); }
.bk-toc-m summary::-webkit-details-marker { display: none; }
.bk-toc-m ol { list-style: none; margin: 0; padding: 0 18px 14px; font-size: 16px; }
.bk-toc-m ol a { display: block; padding: 9px 0; color: var(--bk-text); text-decoration: none; border-top: 1px solid #f0f1f8; }

/* ---------- Article prose ---------- */
.bk-article { flex: 999 1 560px; min-width: 0; max-width: 740px; font-size: 18px; line-height: 1.7; color: var(--bk-text); }
.bk-article p { margin: 0 0 18px; }
.bk-article h2 { font-size: clamp(24px, 2.6vw, 30px); font-weight: 800; letter-spacing: -.02em; line-height: 1.25; color: var(--bk-ink); margin: 64px 0 16px; scroll-margin-top: calc(var(--nav-h, 64px) + 24px); text-wrap: balance; }
.bk-article h3 { font-size: 21px; font-weight: 700; color: var(--bk-ink); margin: 32px 0 10px; line-height: 1.35; }
.bk-article strong { color: var(--bk-ink); }
.bk-article :is(ul, ol):not([class]) { margin: 0 0 18px; padding-left: 1.3em; }
.bk-article :is(ul, ol):not([class]) li { margin-bottom: 8px; }
.bk-article .src-note, .bk-note { font-size: 14.5px; color: var(--bk-muted); }
.bk-label { font-size: 13px; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; margin-bottom: 12px; display: block; }

/* Tóm tắt nhanh */
.bk-tldr { background: var(--bk-mint-soft); border-radius: 18px; padding: clamp(20px, 2.4vw, 28px); margin-bottom: 36px; }
.bk-tldr .bk-label { color: var(--bk-mint-dark); }
.bk-tldr ul { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 12px; font-size: 16.5px; line-height: 1.55; color: var(--bk-ink); }
.bk-tldr li { display: flex; gap: 12px; }
.bk-tldr li .bk-ico { font-size: 22px; color: var(--bk-mint-dark); stroke-width: 2.5; margin-top: 1px; }

/* Callout (dùng kèm .t-sky / .t-pink / .t-sun) */
.bk-callout { display: flex; gap: 14px; align-items: flex-start; flex-wrap: wrap; background: var(--tn-soft); color: var(--tn-dark); border: 1px solid color-mix(in srgb, var(--tn) 35%, transparent); border-radius: 14px; padding: 16px 18px; font-size: 16px; line-height: 1.6; margin-bottom: 18px; }
.bk-callout > .bk-ico { font-size: 22px; margin-top: 1px; }
.bk-callout > span { flex: 1 1 260px; }
.bk-callout strong { color: inherit; }

/* Hộp tối */
.bk-dark { background: var(--bk-ink); color: #e9eaf7; border-radius: 18px; padding: clamp(20px, 2.4vw, 28px); font-size: 16.5px; line-height: 1.65; margin-bottom: 18px; }
.bk-dark .bk-label { color: var(--bk-mint); }
.bk-dark p { margin: 0 0 10px; } .bk-dark p:last-child { margin: 0; }
.bk-dark strong { color: #fff; }

/* Card kiểu / bước */
.bk-types { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(210px, 100%), 1fr)); gap: 16px; margin: 24px 0; }
.bk-type { border: 1px solid var(--bk-line); border-radius: 18px; padding: 20px; display: flex; flex-direction: column; gap: 10px; background: #fff; }
.bk-type__top { display: flex; align-items: center; justify-content: space-between; }
.bk-type__icon { width: 44px; height: 44px; border-radius: 12px; background: var(--tn-soft); color: var(--tn-dark); display: flex; align-items: center; justify-content: center; font-size: 22px; }
.bk-type__num { font-family: var(--bk-mono); font-size: 14px; font-weight: 700; color: var(--bk-faint); }
.bk-type__title { font-size: 18px; font-weight: 700; color: var(--bk-ink); line-height: 1.3; }
.bk-type__desc { font-size: 15.5px; line-height: 1.55; }
.bk-type__ex { margin-top: auto; font-size: 14px; line-height: 1.5; background: var(--tn-soft); color: var(--tn-dark); border-radius: 10px; padding: 10px 12px; }

/* Sơ đồ luồng */
.bk-flow { list-style: none; margin: 22px 0 24px; padding: 0; display: grid; grid-template-columns: repeat(auto-fit, minmax(min(150px, 100%), 1fr)); gap: 10px; }
.bk-flow li { background: var(--tn-soft); border-radius: 14px; padding: 14px; display: flex; flex-direction: column; gap: 4px; }
.bk-flow__n { font-family: var(--bk-mono); font-size: 12px; font-weight: 700; color: var(--tn-dark); }
.bk-flow strong { font-size: 15.5px; line-height: 1.35; }
.bk-flow span:last-child { font-size: 13.5px; line-height: 1.45; }
.bk-flow li.is-final { background: var(--bk-blue); color: #fff; }
.bk-flow li.is-final strong { color: #fff; }
.bk-flow li.is-final .bk-flow__n { color: var(--bk-mint); }

/* Tab */
.bk-tabs { display: flex; gap: 8px; overflow-x: auto; padding-bottom: 4px; margin-bottom: 16px; }
.bk-tab { flex: none; min-height: 44px; padding: 10px 18px; border-radius: 99px; border: 1px solid var(--bk-line-strong); background: #fff; color: var(--bk-ink); font: inherit; font-size: 15px; font-weight: 600; cursor: pointer; }
.bk-tab[aria-selected="true"] { background: var(--bk-ink); border-color: var(--bk-ink); color: #fff; }
.bk-tabpanel { border: 1px solid var(--bk-line); border-radius: 18px; padding: clamp(18px, 2.4vw, 28px); margin-bottom: 18px; font-size: 16.5px; }
.bk-tabpanel[hidden] { display: none; }
.bk-tabpanel > * + * { margin-top: 12px; }
.bk-tabpanel p { margin: 0; }
.bk-source { display: inline-block; font-size: 14px; font-weight: 600; }

/* Ô mã bấm */
.bk-code-row { display: flex; flex-wrap: wrap; align-items: center; gap: 12px 16px; padding: 14px 16px; background: var(--bk-blue-soft); border-radius: 14px; }
.bk-code { font-family: var(--bk-mono); font-size: 22px; font-weight: 700; color: var(--bk-blue); background: #fff; border: 1px solid var(--bk-line-strong); border-radius: 10px; padding: 6px 12px; }
.bk-code-row > div { flex: 1 1 220px; display: flex; flex-direction: column; line-height: 1.45; }
.bk-code-row strong { font-size: 16.5px; }
.bk-code-row span { font-size: 15px; }

/* Tag nhiều màu */
.bk-tags { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 18px; padding: 0; list-style: none; }
.bk-tag { background: var(--tn-soft); color: var(--tn-dark); border-radius: 99px; padding: 8px 14px; font-size: 15px; font-weight: 600; line-height: 1.3; }

/* Câu hỏi then chốt */
.bk-ask { border: 2px solid var(--bk-blue); border-radius: 18px; padding: 18px 20px; display: flex; flex-direction: column; gap: 6px; margin-bottom: 18px; }
.bk-ask .bk-label { color: var(--bk-blue); margin: 0; }
.bk-ask p { margin: 0 !important; font-size: 19px; font-weight: 700; color: var(--bk-ink); line-height: 1.4; }

/* Nút */
.bk-btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 48px; padding: 0 22px; border-radius: 12px; font-weight: 700; font-size: 16px; text-decoration: none; border: 1px solid transparent; }
.bk-btn--primary { background: var(--bk-blue); color: #fff !important; }
.bk-btn--primary:hover { background: var(--bk-blue-dark); }
.bk-btn--white { background: #fff; color: var(--bk-blue) !important; }
.bk-btn--ghost { background: #fff; color: var(--bk-ink) !important; border-color: var(--bk-line-strong); }
.bk-btn--ghost-dark { background: transparent; color: #fff !important; border-color: rgba(255,255,255,.45); }

/* Thẻ giá AIVA */
.bk-price { border: 1px solid var(--bk-line-strong); border-radius: 22px; overflow: hidden; margin-bottom: 18px; box-shadow: 0 16px 40px rgba(28, 23, 255, .08); display: flex; flex-wrap: wrap; }
.bk-price__main { flex: 1 1 260px; background: var(--bk-blue); color: #fff; padding: clamp(22px, 3vw, 32px); display: flex; flex-direction: column; gap: 8px; }
.bk-price__kicker { font-size: 14px; font-weight: 700; color: var(--bk-mint); }
.bk-price__amount { display: flex; align-items: baseline; gap: 10px; }
.bk-price__amount b { font-size: 56px; font-weight: 800; letter-spacing: -.03em; line-height: 1; }
.bk-price__amount span { font-size: 17px; font-weight: 600; }
.bk-price__main .bk-btn { margin-top: 12px; }
.bk-price__main small { font-size: 14px; text-align: center; }
.bk-price__list { flex: 1 1 280px; padding: clamp(22px, 3vw, 32px); display: flex; flex-direction: column; gap: 14px; }
.bk-price__list .bk-label { color: var(--bk-muted); margin: 0; }
.bk-checks { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 9px; font-size: 15.5px; line-height: 1.45; color: var(--bk-ink); }
.bk-checks li { display: flex; gap: 10px; }
.bk-checks .bk-ico { font-size: 18px; color: var(--bk-blue); stroke-width: 2.6; margin-top: 2px; }
.bk-checks li.is-no { color: var(--bk-muted); }
.bk-checks li.is-no .bk-ico { color: var(--bk-faint); }
.bk-price__foot { border-top: 1px solid var(--bk-line); padding-top: 12px; font-size: 14px; line-height: 1.55; color: var(--bk-muted); }

/* Gói lịch */
.bk-plans { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(250px, 100%), 1fr)); gap: 16px; margin: 22px 0 18px; }
.bk-plan { border: 1px solid var(--bk-line-strong); border-radius: 18px; padding: 22px; display: flex; flex-direction: column; gap: 12px; }
.bk-plan.t-mint { background: var(--bk-mint-soft); border-color: #b8ecc8; }
.bk-plan--featured { border: 2px solid var(--bk-blue); padding: 21px; }
.bk-plan__name { font-size: 15px; font-weight: 700; color: var(--tn-dark, var(--bk-blue)); }
.bk-plan__price { display: flex; align-items: baseline; gap: 8px; font-size: 15px; }
.bk-plan__price b { font-size: 40px; font-weight: 800; letter-spacing: -.03em; color: var(--bk-ink); line-height: 1; }
.bk-plan .bk-checks { font-size: 15px; }

/* Bảng */
.bk-table-wrap { overflow-x: auto; border: 1px solid var(--bk-line); border-radius: 16px; margin-bottom: 12px; }
.bk-table-wrap table { width: 100%; min-width: 520px; border-collapse: collapse; font-size: 15.5px; line-height: 1.5; margin: 0; }
.bk-table-wrap th { background: var(--bk-blue-soft); text-align: left; padding: 14px 18px; font-weight: 700; color: var(--bk-ink); }
.bk-table-wrap td { padding: 14px 18px; vertical-align: top; border-top: 1px solid var(--bk-line); }

/* Cảnh báo */
.bk-warn { display: flex; gap: 12px; background: var(--bk-sun-soft); color: var(--bk-sun-dark); border-radius: 14px; padding: 14px 16px; font-size: 15.5px; line-height: 1.55; }
.bk-warn .bk-ico { font-size: 20px; margin-top: 2px; }

/* Checklist */
.bk-progress { display: flex; align-items: center; gap: 14px; margin: 4px 0 16px; }
.bk-progress__bar { flex: 1; height: 8px; background: var(--bk-line); border-radius: 99px; overflow: hidden; }
.bk-progress__bar i { display: block; height: 100%; width: 0; background: var(--bk-blue); border-radius: 99px; transition: width .25s; }
.bk-progress__txt { font-size: 14px; font-weight: 700; color: var(--bk-ink); white-space: nowrap; }
.bk-checklist { list-style: none; margin: 0 0 18px; padding: 0; display: flex; flex-direction: column; gap: 10px; }
.bk-checklist label { display: flex; gap: 14px; align-items: flex-start; border: 1px solid var(--bk-line); background: #fff; border-radius: 14px; padding: 14px 16px; cursor: pointer; font-size: 16px; line-height: 1.55; }
.bk-checklist input { width: 22px; height: 22px; margin: 2px 0 0; flex: none; accent-color: var(--bk-blue); }
.bk-checklist label:has(input:checked) { background: var(--bk-blue-soft); border-color: #c9c7ff; }

/* FAQ */
.bk-faq { border-top: 1px solid var(--bk-line); }
.bk-faq details { border-bottom: 1px solid var(--bk-line); }
.bk-faq summary { list-style: none; cursor: pointer; display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 18px 2px; min-height: 44px; font-size: 17px; font-weight: 700; color: var(--bk-ink); line-height: 1.4; }
.bk-faq summary::-webkit-details-marker { display: none; }
.bk-faq summary .bk-ico, .bk-toc-m summary .bk-ico { font-size: 20px; transition: transform .2s; }
.bk-faq details[open] summary .bk-ico, .bk-toc-m[open] summary .bk-ico { transform: rotate(180deg); }
.bk-faq details p { margin: 0 0 18px; font-size: 16px; line-height: 1.65; }

/* ---------- CTA cuối bài ---------- */
.bk-cta-sec { padding-block: 48px; }
.bk-cta { background-color: var(--bk-blue); background-image: radial-gradient(rgba(255,255,255,.12) 1px, transparent 1.4px); background-size: 22px 22px; color: #fff; border-radius: 28px; padding: clamp(24px, 4.5vw, 56px); display: flex; flex-wrap: wrap; align-items: center; gap: 32px; }
.bk-cta__main { flex: 1 1 420px; min-width: 0; display: flex; flex-direction: column; gap: 16px; }
.bk-cta__main h2 { margin: 0; font-size: clamp(28px, 3.4vw, 42px); line-height: 1.15; font-weight: 800; letter-spacing: -.025em; text-wrap: balance; }
.bk-cta__main p { margin: 0; font-size: 17px; line-height: 1.6; max-width: 520px; color: #e6e5ff; }
.bk-cta__btns { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 6px; }
.bk-cta__btns .bk-btn { min-height: 52px; }
.bk-cta__side { flex: 1 1 300px; min-width: 0; background: #fff; color: var(--bk-ink); border-radius: 20px; padding: 24px; display: flex; flex-direction: column; gap: 10px; }
.bk-cta__side-kicker { display: inline-flex; align-items: center; gap: 8px; font-size: 14px; font-weight: 700; color: var(--bk-blue); }
.bk-cta__side-title { font-size: 20px; font-weight: 800; line-height: 1.3; }
.bk-cta__side p { margin: 0; font-size: 15px; line-height: 1.55; color: var(--bk-text); }
.bk-cta__side-links { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 6px; font-size: 15px; font-weight: 700; }

/* ---------- Card bài viết (related + index) ---------- */
.bk-related { padding-block: 24px 72px; }
.bk-sec-head { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; flex-wrap: wrap; margin-bottom: 24px; }
.bk-sec-head h2 { margin: 0; font-size: clamp(24px, 2.6vw, 30px); font-weight: 800; letter-spacing: -.02em; }
.bk-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(280px, 100%), 1fr)); gap: 24px; }
.bk-card { display: flex; flex-direction: column; text-decoration: none; color: var(--bk-ink) !important; border: 1px solid var(--bk-line); border-radius: 20px; overflow: hidden; background: #fff; transition: transform .15s, box-shadow .15s; }
.bk-card:hover { transform: translateY(-3px); box-shadow: 0 16px 36px rgba(11, 11, 43, .10); }
.bk-card__media { aspect-ratio: 1200 / 630; background: var(--bk-ink-soft); }
.bk-card__media img { width: 100%; height: 100%; object-fit: cover; display: block; }
.bk-card__body { padding: 16px 20px 22px; display: flex; flex-direction: column; gap: 8px; }
.bk-card__title { font-size: 19px; font-weight: 700; line-height: 1.35; }
.bk-card__excerpt { font-size: 15px; line-height: 1.55; color: var(--bk-muted); }
.bk-card__meta { font-size: 13.5px; color: var(--bk-muted); }
.bk-card__more { font-size: 14px; font-weight: 700; color: var(--bk-blue); margin-top: 4px; }

/* Index blog */
.bk-index-head { display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between; gap: 24px; padding-block: clamp(32px, 5vw, 64px) 32px; }
.bk-index-head h1 { margin: 0 0 8px; font-size: clamp(34px, 4.4vw, 52px); font-weight: 800; letter-spacing: -.03em; line-height: 1.1; }
.bk-index-head p { margin: 0; font-size: 17px; color: var(--bk-muted); }
.bk-filters { display: flex; flex-wrap: wrap; gap: 8px; }
.bk-filter { min-height: 44px; padding: 0 16px; border-radius: 99px; border: 1px solid var(--bk-line-strong); background: #fff; color: var(--bk-ink); font: inherit; font-size: 14px; font-weight: 600; cursor: pointer; }
.bk-filter[aria-pressed="true"] { background: var(--bk-ink); border-color: var(--bk-ink); color: #fff; }
.bk-featured { display: flex; flex-wrap: wrap; text-decoration: none; color: var(--bk-ink) !important; border: 1px solid var(--bk-line); border-radius: 24px; overflow: hidden; margin-bottom: 36px; }
.bk-featured { align-items: center; }
.bk-featured .bk-card__media { flex: 1 1 520px; background: none; }
.bk-featured__body { flex: 1 1 320px; padding: clamp(22px, 3vw, 36px); display: flex; flex-direction: column; justify-content: center; gap: 14px; }
.bk-featured__title { font-size: clamp(22px, 2.4vw, 28px); font-weight: 800; line-height: 1.2; letter-spacing: -.02em; }
.bk-featured__body p { margin: 0; font-size: 16px; line-height: 1.6; color: var(--bk-text); }
.bk-card[hidden] { display: none; }

/* ---------- Thanh CTA mobile ---------- */
.bk-sticky { display: none; position: sticky; bottom: 0; z-index: 20; background: #fff; border-top: 1px solid var(--bk-line); padding: 12px 16px calc(12px + env(safe-area-inset-bottom)); align-items: center; justify-content: space-between; gap: 12px; box-shadow: 0 -8px 24px rgba(11, 11, 43, .08); }
.bk-sticky div { display: flex; flex-direction: column; line-height: 1.3; }
.bk-sticky strong { font-size: 15px; }
.bk-sticky span { font-size: 13px; color: var(--bk-muted); }
.bk-sticky .bk-btn { min-height: 46px; padding: 0 20px; font-size: 15px; }

/* ---------- Ảnh bìa (dựng bằng cover.js; production dùng PNG) ---------- */
.bk-cover { container-type: inline-size; width: 100%; font-family: var(--bk-font); }
.bk-cover, .bk-cover *, .bk-cover *::before, .bk-cover *::after { box-sizing: border-box; }
.bk-cover__frame { position: relative; aspect-ratio: 1200 / 630; overflow: hidden; padding: 5.5cqi; display: grid; grid-template-columns: 54fr 46fr; gap: 3cqi;
  background-color: var(--cv-bg); color: var(--cv-fg);
  background-image: radial-gradient(var(--cv-dot) .16cqi, transparent .22cqi); background-size: 2.6cqi 2.6cqi; }
.bk-cover__text { display: flex; flex-direction: column; justify-content: space-between; min-width: 0; }
.bk-cover__chip { align-self: flex-start; font-size: 1.7cqi; font-weight: 700; letter-spacing: .02em; padding: .8cqi 1.7cqi; border-radius: 99px; background: var(--cv-chip-bg); color: var(--cv-chip-fg); }
.bk-cover__title { font-size: 5.3cqi; font-weight: 800; line-height: 1.1; letter-spacing: -.025em; text-wrap: balance; }
.bk-cover__brand { display: flex; align-items: center; gap: 1cqi; font-size: 1.7cqi; font-weight: 600; }
.bk-cover__brand svg { width: 3cqi; height: 3cqi; }
.bk-cover__art { position: relative; min-width: 0; display: flex; align-items: center; justify-content: center; }
.bk-cover svg.bk-ico { width: 1em; height: 1em; }
/* tones */
.bk-cover.cv-blue     { --cv-bg: #1c17ff; --cv-fg: #fff; --cv-dot: rgba(255,255,255,.14); --cv-chip-bg: #8ee8a6; --cv-chip-fg: #0b0b2b; --cv-bub-bg: rgba(255,255,255,.16); --cv-bub-fg: #fff; }
.bk-cover.cv-grape    { --cv-bg: #6d3ff0; --cv-fg: #fff; --cv-dot: rgba(255,255,255,.14); --cv-chip-bg: #ffc53d; --cv-chip-fg: #0b0b2b; --cv-bub-bg: rgba(255,255,255,.16); --cv-bub-fg: #fff; }
.bk-cover.cv-ink      { --cv-bg: #0b0b2b; --cv-fg: #fff; --cv-dot: rgba(255,255,255,.10); --cv-chip-bg: #8ee8a6; --cv-chip-fg: #0b0b2b; --cv-bub-bg: rgba(255,255,255,.16); --cv-bub-fg: #fff; }
.bk-cover.cv-mint     { --cv-bg: #8ee8a6; --cv-fg: #0b0b2b; --cv-dot: rgba(11,11,43,.13); --cv-chip-bg: #0b0b2b; --cv-chip-fg: #fff; --cv-bub-bg: rgba(11,11,43,.10); --cv-bub-fg: #0b0b2b; }
.bk-cover.cv-coral    { --cv-bg: #ff6b4a; --cv-fg: #0b0b2b; --cv-dot: rgba(11,11,43,.13); --cv-chip-bg: #0b0b2b; --cv-chip-fg: #fff; --cv-bub-bg: rgba(11,11,43,.10); --cv-bub-fg: #0b0b2b; }
.bk-cover.cv-sun      { --cv-bg: #ffc53d; --cv-fg: #0b0b2b; --cv-dot: rgba(11,11,43,.13); --cv-chip-bg: #0b0b2b; --cv-chip-fg: #fff; --cv-bub-bg: rgba(11,11,43,.10); --cv-bub-fg: #0b0b2b; }
.bk-cover.cv-sky      { --cv-bg: #3db8ff; --cv-fg: #0b0b2b; --cv-dot: rgba(11,11,43,.13); --cv-chip-bg: #0b0b2b; --cv-chip-fg: #fff; --cv-bub-bg: rgba(11,11,43,.10); --cv-bub-fg: #0b0b2b; }
.bk-cover.cv-pink     { --cv-bg: #ff5fa2; --cv-fg: #0b0b2b; --cv-dot: rgba(11,11,43,.13); --cv-chip-bg: #0b0b2b; --cv-chip-fg: #fff; --cv-bub-bg: rgba(11,11,43,.10); --cv-bub-fg: #0b0b2b; }
.bk-cover.cv-lavender { --cv-bg: #eceaff; --cv-fg: #0b0b2b; --cv-dot: rgba(28,23,255,.14); --cv-chip-bg: #1c17ff; --cv-chip-fg: #fff; --cv-bub-bg: rgba(11,11,43,.10); --cv-bub-fg: #0b0b2b; }
/* motif pieces */
.cv-card { background: #fff; color: #0b0b2b; border-radius: 2.4cqi; padding: 2.4cqi; box-shadow: 0 2cqi 5cqi rgba(5,5,40,.25); display: flex; flex-direction: column; gap: 1.3cqi; width: 100%; max-width: 38cqi; }
.cv-row { display: flex; align-items: center; justify-content: space-between; gap: 1cqi; padding: 1.1cqi 1.4cqi; background: #f4f5ff; border-radius: 1.2cqi; font-size: 1.65cqi; font-weight: 600; }
.cv-row b { color: #1c17ff; }
.cv-head { display: flex; align-items: center; gap: 1.3cqi; }
.cv-head__icon { width: 4.6cqi; height: 4.6cqi; border-radius: 50%; background: #1c17ff; color: #fff; display: flex; align-items: center; justify-content: center; font-size: 2.3cqi; }
.cv-head small { display: block; font-size: 1.4cqi; color: #565875; font-weight: 500; }
.cv-head b { display: block; font-size: 2cqi; }
.cv-pill { position: absolute; display: flex; align-items: center; gap: .8cqi; font-size: 1.6cqi; font-weight: 700; padding: 1cqi 1.8cqi; border-radius: 99px; box-shadow: 0 1cqi 3cqi rgba(5,5,40,.2); white-space: nowrap; }
.cv-pill--mint { background: #8ee8a6; color: #0b0b2b; }
.cv-pill--ink { background: #0b0b2b; color: #fff; }
.cv-pill--white { background: #fff; color: #0b0b2b; border-radius: 1.6cqi; }
.cv-ring { position: relative; width: 28cqi; height: 28cqi; }
.cv-ring i { position: absolute; border-radius: 50%; border: .35cqi solid rgba(11,11,43,.2); }
.cv-ring i:nth-child(1) { inset: 0; } .cv-ring i:nth-child(2) { inset: 3.8cqi; border-color: rgba(11,11,43,.3); }
.cv-ring__core { position: absolute; inset: 7.6cqi; border-radius: 50%; background: #0b0b2b; color: #8ee8a6; display: flex; align-items: center; justify-content: center; font-size: 5.6cqi; }
.cv-sign { position: absolute; left: 2cqi; top: 7cqi; width: 26cqi; transform: rotate(-4deg); background: #fff; color: #0b0b2b; border-radius: 1.8cqi; padding: 2.6cqi 2.4cqi; box-shadow: 0 2cqi 5cqi rgba(0,0,0,.3); display: flex; flex-direction: column; gap: .8cqi; align-items: center; text-align: center; }
.cv-sign small { font-size: 1.4cqi; font-weight: 600; color: #565875; letter-spacing: .08em; }
.cv-sign b { font-size: 4.2cqi; font-weight: 800; line-height: 1; }
.cv-moon { position: absolute; right: 1cqi; top: 0; width: 9cqi; height: 9cqi; border-radius: 50%; box-shadow: inset -2.4cqi -1.2cqi 0 0 #8ee8a6; }
.cv-missed { display: flex; align-items: center; gap: 1.2cqi; padding: 1cqi 0; border-top: 1px solid #e4e5f2; font-size: 1.65cqi; }
.cv-missed .bk-ico { color: #1c17ff; font-size: 2.2cqi; }
.cv-missed span { flex: 1; font-weight: 600; } .cv-missed em { font-style: normal; color: #565875; }
.cv-badge { background: #1c17ff; color: #fff; font-size: 1.5cqi; min-width: 3.2cqi; height: 3.2cqi; border-radius: 99px; display: flex; align-items: center; justify-content: center; }
.cv-chat { width: 100%; max-width: 38cqi; display: flex; flex-direction: column; gap: 1.6cqi; }
.cv-bubble { max-width: 85%; font-size: 1.8cqi; font-weight: 500; line-height: 1.35; padding: 1.4cqi 2cqi; }
.cv-bubble--them { align-self: flex-end; background: var(--cv-bub-bg); color: var(--cv-bub-fg); border-radius: 2cqi 2cqi .6cqi 2cqi; }
.cv-bubble--aiva { align-self: flex-start; background: #fff; color: #0b0b2b; border-radius: 2cqi 2cqi 2cqi .6cqi; }
.cv-bubble--aiva small { display: block; font-size: 1.3cqi; font-weight: 800; color: #1c17ff; letter-spacing: .06em; }

/* ---------- Responsive ---------- */
@media (max-width: 980px) {
  .bk-toc { display: none; }
  .bk-toc-m { display: block; }
  .bk-sticky { display: flex; }
}
@media (max-width: 560px) {
  .bk-article { font-size: 17px; }
  .bk-article h2 { margin-top: 48px; }
  .bk-price__amount b { font-size: 46px; }
}
@media (prefers-reduced-motion: reduce) {
  .bk-card, .bk-progress__bar i, .bk-faq summary .bk-ico { transition: none; }
}

/* ---------- Ảnh <img> (production) ---------- */
.bk-hero__media img { display: block; width: 100%; height: auto; aspect-ratio: 1200 / 630; }

/* ---------- Cover: biến thể mới ---------- */
.cv-vs { display: flex; align-items: center; gap: 1.4cqi; width: 100%; max-width: 40cqi; position: relative; }
.cv-vs .cv-card { max-width: none; flex: 1; padding: 1.8cqi; gap: 1cqi; }
.cv-vs__tag { font-size: 1.4cqi; font-weight: 800; letter-spacing: .08em; color: #565875; display: flex; align-items: center; justify-content: space-between; }
.cv-vs__line { display: flex; align-items: center; gap: 1cqi; padding: 1cqi 1.2cqi; background: #f4f5ff; border-radius: 1.1cqi; }
.cv-vs__line i { display: block; height: 1cqi; border-radius: 99px; background: #d8daf0; flex: 1; }
.cv-vs__line .bk-ico { font-size: 2cqi; flex: none; color: #8a8ca8; }
.cv-vs .cv-card--win { outline: .5cqi solid #8ee8a6; }
.cv-vs .cv-card--win .cv-vs__line .bk-ico { color: #0b5c2b; }
.cv-vs .cv-card--win .cv-vs__line i { background: #b8ecc8; }
.cv-vs__vs { position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%); z-index: 1; width: 4.6cqi; height: 4.6cqi; border-radius: 50%; background: #0b0b2b; color: #fff; font-size: 1.5cqi; font-weight: 800; display: flex; align-items: center; justify-content: center; box-shadow: 0 .6cqi 1.6cqi rgba(5,5,40,.3); }
.cv-cal { max-width: 38cqi; }
.cv-cal__cols { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1cqi; }
.cv-cal__col { display: flex; flex-direction: column; gap: .9cqi; }
.cv-cal__col b { font-size: 1.4cqi; text-align: center; color: #565875; }
.cv-cal__slot { border-radius: 1cqi; height: 4.4cqi; background: #f4f5ff; }
.cv-cal__slot.is-a { background: #ffe9e3; } .cv-cal__slot.is-b { background: #fff4d6; } .cv-cal__slot.is-c { background: #f0e9ff; }
.cv-cal__slot.is-tall { height: 8.4cqi; } .cv-cal__slot.is-new { background: #1c17ff; }

/* ---------- Bổ sung cho script migrate ---------- */
.bk-cta__side-note { font-size: 13px; font-weight: 600; color: var(--bk-muted); }
.bk-cta__side-links a { text-decoration: none; }
.bk-cta__btns a, .bk-toc-cta a { text-decoration: none; }
.bk-sticky strong { display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.bk-sticky .bk-btn { flex: none; }
.bk-article > .bk-faq + p, .bk-article table { margin-top: 0; }
.bk-article img { max-width: 100%; height: auto; }
.bk-article blockquote { margin: 0 0 18px; padding: 4px 0 4px 18px; border-left: 3px solid var(--bk-blue); color: var(--bk-text); }

/* Link trong đoạn văn phải nhận ra được không chỉ bằng màu (Lighthouse: link-in-text-block) */
.bk-article :is(p, li, td, dd) a:not([class]) { text-decoration: underline; text-underline-offset: 3px; text-decoration-thickness: 1px; }