/* =========================================================
   Kiến thức (kien-thuc.html) + Bài viết (bai-viet.html)
   Loaded after style.css. Follows the approved blog mockup.
   ========================================================= */
.page-blog { --b-ink: #0b1f4d; --b-blue: #1467e6; --b-muted: #55677f; --b-line: #e2eaf5; --gutter: max(20px, calc((100% - 1240px) / 2)); background: #f6f9fe; }
.page-blog h1, .page-blog h2, .page-blog h3 { color: var(--b-ink); font-family: var(--display); }
.page-blog .pill.primary { background: linear-gradient(90deg, #1a6dff, #2b86ff); color: #fff; }
.pill.ghost-dark { border: 1.5px solid #1b3a78; color: var(--b-ink); background: #fff; }
.pill.ghost-dark:hover { background: var(--b-ink); color: #fff; }
.kt-link { display: inline-flex; align-items: center; gap: 6px; color: var(--b-blue); font: 600 13.5px var(--display); background: none; border: 0; padding: 0; }
.kt-link svg { transition: transform .25s; }
.kt-link:hover svg { transform: translateX(3px); }

/* Category tag colours */
.kt-tag { display: inline-block; padding: 2px 10px; border-radius: 6px; font: 600 11.5px var(--display); color: #fff; background: #1467e6; }
.kt-tag.website { background: #1467e6; } .kt-tag.uiux { background: #6d4cf2; } .kt-tag.seo { background: #0aa5c9; }
.kt-tag.marketing { background: #f08a24; } .kt-tag.congnghe { background: #1d8de0; } .kt-tag.kinhnghiem { background: #18a874; }
.kt-meta { display: flex; align-items: center; gap: 10px; font-size: 12.5px; color: var(--b-muted); flex-wrap: wrap; }
.kt-meta svg { width: 14px; height: 14px; margin-right: 4px; vertical-align: -2px; }
.kt-meta > span { display: inline-flex; align-items: center; }

/* ---------- Hero ---------- */
.kt-hero { position: relative; display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr); gap: 34px; align-items: center; padding: 108px var(--gutter) 46px; overflow: hidden;
  background: linear-gradient(180deg, rgba(234,243,255,.94), rgba(244,248,255,.96)), url('https://images.unsplash.com/photo-1486406146926-c627a92ad1ab?auto=format&fit=crop&w=1800&q=60') center/cover; }
.kt-kicker { display: inline-flex; align-items: center; gap: 8px; padding: 6px 14px; border-radius: 99px; border: 1.5px solid #c9dbf6; background: #fff; color: var(--b-ink); font: 700 11.5px var(--display); letter-spacing: .14em; text-transform: uppercase; }
.kt-kicker svg { color: var(--b-blue); }
.kt-hero h1 { font-size: clamp(28px, 2.7vw, 38px); line-height: 1.18; margin: 16px 0 14px; letter-spacing: -.01em; }
.kt-hero-copy > p { color: var(--b-muted); max-width: 520px; margin: 0 0 26px; }
.kt-hero-points { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(3, auto); gap: 18px; }
.kt-hero-points li { display: grid; grid-template-columns: 40px 1fr; column-gap: 10px; align-items: center; }
.kt-hero-points span { grid-row: span 2; width: 40px; height: 40px; border-radius: 50%; display: grid; place-items: center; background: #fff; color: var(--b-blue); box-shadow: 0 8px 18px -12px rgba(20,103,230,.6); }
.kt-hero-points b { font: 600 13px var(--display); color: var(--b-ink); }
.kt-hero-points small { font-size: 11.5px; color: var(--b-muted); }

.kt-hero-art { position: relative; display: grid; grid-template-columns: 1.1fr 1fr; gap: 14px; perspective: 1400px; }
.kt-hcard { position: relative; border-radius: 16px; overflow: hidden; color: #fff; display: flex; flex-direction: column; justify-content: flex-end; padding: 18px; min-height: 160px; isolation: isolate;
  box-shadow: 0 30px 50px -28px rgba(8,28,70,.55); transform: rotateY(var(--ry, -6deg)) rotateX(var(--rx, 2deg)); transition: transform .8s cubic-bezier(.2,.7,.2,1); }
.kt-hcard img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; z-index: -2; transition: transform .8s; }
.kt-hcard::before { content: ""; position: absolute; inset: 0; z-index: -1; background: linear-gradient(0deg, rgba(5,20,50,.92), rgba(5,20,50,.15) 70%); }
.kt-hcard:hover img { transform: scale(1.06); }
.kt-hcard.big { grid-row: span 2; min-height: 340px; }
.kt-hcard h3 { color: #fff; font-size: 18px; line-height: 1.3; margin: 8px 0 0; }
.kt-hcard.big h3 { font-size: 22px; }
.kt-hcard .kt-meta { color: #d4e2f7; }
.kt-hero-next { position: absolute; right: -14px; top: 50%; transform: translateY(-50%); width: 40px; height: 40px; border-radius: 50%; border: 0; background: #fff; color: var(--b-ink); display: grid; place-items: center; box-shadow: 0 10px 22px -12px rgba(8,28,70,.6); z-index: 3; }

/* ---------- Filter bar ---------- */
.kt-filter { position: sticky; top: 64px; z-index: 30; display: flex; justify-content: space-between; align-items: center; gap: 16px; margin: -26px var(--gutter) 0; padding: 12px 14px; background: rgba(255,255,255,.96); backdrop-filter: blur(10px); border: 1px solid var(--b-line); border-radius: 14px; box-shadow: 0 18px 40px -26px rgba(8,28,70,.45); }
.kt-tabs { display: flex; gap: 8px; flex-wrap: wrap; }
.kt-tabs button { height: 38px; padding: 0 18px; border-radius: 9px; border: 1px solid var(--b-line); background: #f4f7fc; font: 600 13px var(--display); color: var(--b-ink); transition: .2s; }
.kt-tabs button:hover { border-color: #b9cff2; }
.kt-tabs button[aria-selected="true"] { background: var(--b-blue); border-color: var(--b-blue); color: #fff; }
.kt-search { display: flex; align-items: center; gap: 8px; height: 38px; padding: 0 12px; border: 1px solid var(--b-line); border-radius: 9px; background: #f4f7fc; min-width: 220px; color: var(--b-muted); }
.kt-search input { border: 0; outline: 0; background: none; font: 13.5px var(--sans); flex: 1; min-width: 0; color: var(--b-ink); }

/* ---------- Sections ---------- */
.kt-sec { padding: 46px var(--gutter) 10px; }
.kt-head { display: flex; justify-content: space-between; align-items: flex-end; gap: 20px; margin-bottom: 20px; }
.kt-head h2 { font-size: clamp(22px, 2.2vw, 28px); margin: 0; }
.kt-head h2 small { font: 400 13px var(--sans); color: var(--b-muted); margin-left: 10px; }
.kt-featured { display: grid; grid-template-columns: 1.2fr 1fr; gap: 20px; }
.kt-feat-big { position: relative; border-radius: 16px; overflow: hidden; min-height: 380px; display: flex; flex-direction: column; justify-content: flex-end; padding: 26px; color: #fff; isolation: isolate; }
.kt-feat-big img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; z-index: -2; transition: transform .8s; }
.kt-feat-big::before { content: ""; position: absolute; inset: 0; z-index: -1; background: linear-gradient(0deg, rgba(5,18,45,.94) 10%, rgba(5,18,45,.2) 70%); }
.kt-feat-big:hover img { transform: scale(1.04); }
.kt-feat-big h3 { color: #fff; font-size: clamp(20px, 2vw, 26px); margin: 10px 0 8px; }
.kt-feat-big p { color: #d4e2f7; margin: 0 0 16px; max-width: 520px; font-size: 14.5px; }
.kt-feat-big .kt-meta { color: #d4e2f7; }
.kt-feat-big .pill { align-self: flex-start; background: #fff; color: var(--b-ink); }
.kt-feat-side { display: grid; gap: 20px; }
.kt-feat-row { display: grid; grid-template-columns: 42% 1fr; border: 1px solid var(--b-line); border-radius: 14px; overflow: hidden; background: #fff; transition: box-shadow .3s, transform .3s; }
.kt-feat-row:hover { box-shadow: 0 20px 40px -26px rgba(8,28,70,.5); transform: translateY(-3px); }
.kt-feat-row img { width: 100%; height: 100%; object-fit: cover; min-height: 170px; }
.kt-feat-row > div { padding: 16px 18px; display: flex; flex-direction: column; gap: 6px; }
.kt-feat-row h3 { font-size: 16.5px; line-height: 1.35; margin: 0; }
.kt-feat-row p { margin: 0; font-size: 13px; color: var(--b-muted); }
.kt-feat-row .kt-btn-sm { align-self: flex-start; margin-top: auto; padding: 5px 12px; border-radius: 8px; border: 1px solid #c9dbf6; color: var(--b-blue); font: 600 12.5px var(--display); }

.kt-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.kt-card { display: flex; flex-direction: column; border: 1px solid var(--b-line); border-radius: 14px; overflow: hidden; background: #fff; transition: box-shadow .3s, transform .3s; }
.kt-card:hover { box-shadow: 0 22px 40px -26px rgba(8,28,70,.5); transform: translateY(-5px); }
.kt-card .ph { height: 160px; overflow: hidden; }
.kt-card img { width: 100%; height: 100%; object-fit: cover; transition: transform .7s; }
.kt-card:hover img { transform: scale(1.06); }
.kt-card .bd { padding: 14px 16px 16px; display: flex; flex-direction: column; flex: 1; gap: 6px; }
.kt-card h3 { font-size: 16px; line-height: 1.35; margin: 2px 0 0; }
.kt-card p { margin: 0; font-size: 13px; color: var(--b-muted); display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.kt-card footer { margin-top: auto; padding-top: 12px; display: flex; justify-content: space-between; align-items: center; font-size: 12.5px; color: var(--b-muted); }
.kt-card footer span { display: inline-flex; align-items: center; gap: 6px; }
.kt-card footer b { color: var(--b-blue); font: 600 12.5px var(--display); }
.kt-empty { text-align: center; color: var(--b-muted); padding: 30px 0; }

/* ---------- Journey ---------- */
.kt-journey { margin-top: 46px; padding: 40px var(--gutter); background: linear-gradient(180deg, #eaf2fe, #f4f8ff); }
.kt-steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.kt-steps article { background: #fff; border: 1px solid var(--b-line); border-radius: 14px; padding: 20px; display: flex; flex-direction: column; }
.kt-steps header { display: flex; align-items: center; gap: 12px; margin-bottom: 12px; }
.kt-steps header > span { width: 46px; height: 46px; border-radius: 12px; display: grid; place-items: center; background: #0b3a8e; color: #fff; font-size: 22px; }
.kt-steps b { color: var(--b-blue); font: 700 18px var(--display); }
.kt-steps h3 { font-size: 16px; margin: 0; }
.kt-steps ul { list-style: none; padding: 0; margin: 0 0 14px; display: grid; gap: 8px; font-size: 13px; color: var(--b-muted); }
.kt-steps li { padding-left: 20px; position: relative; }
.kt-steps li::before { content: "✓"; position: absolute; left: 0; color: var(--b-blue); font-weight: 700; }
.kt-steps li a:hover { color: var(--b-blue); }
.kt-steps .kt-link { margin-top: auto; }

/* ---------- Popular ---------- */
.kt-popular { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(5, 1fr); gap: 18px; }
.kt-popular a { display: grid; grid-template-columns: auto 1fr; gap: 6px 12px; }
.kt-popular .no { grid-row: span 3; font: 300 40px/1 var(--display); color: var(--b-blue); }
.kt-popular h3 { font-size: 14px; line-height: 1.35; margin: 0; }
.kt-popular a:hover h3 { color: var(--b-blue); }
.kt-popular .row { display: flex; gap: 10px; align-items: center; }
.kt-popular img { width: 64px; height: 44px; border-radius: 6px; object-fit: cover; }

/* ---------- Newsletter ---------- */
.kt-news { margin-top: 50px; display: grid; grid-template-columns: 1.1fr auto 1fr; gap: 30px; align-items: center; padding: 36px var(--gutter); color: #fff;
  background: radial-gradient(60% 120% at 70% 50%, rgba(40,120,255,.35), transparent 70%), linear-gradient(90deg, #04163a, #0a2e78); }
.kt-news-copy span { font: 700 11.5px var(--display); letter-spacing: .16em; text-transform: uppercase; color: #8fc0ff; }
.kt-news-copy h2 { color: #fff; font-size: clamp(22px, 2.2vw, 28px); margin: 8px 0 6px; }
.kt-news-copy p { margin: 0; color: #c2d4f2; font-size: 14px; }
.kt-news-art { width: 110px !important; height: 84px !important; animation: ktFloat 4s ease-in-out infinite; }
@keyframes ktFloat { 50% { transform: translateY(-8px) rotate(-3deg); } }
.kt-news-row { display: flex; background: #fff; border-radius: 10px; padding: 5px; }
.kt-news-row input { flex: 1; border: 0; outline: 0; padding: 0 12px; font: 14px var(--sans); min-width: 0; }
.kt-news-form ul { list-style: none; padding: 0; margin: 12px 0 0; display: flex; gap: 16px; flex-wrap: wrap; font-size: 12.5px; color: #c2d4f2; }
.kt-news-form li { display: inline-flex; align-items: center; gap: 6px; }
.kt-news-form li svg { color: #fff; }
.kt-msg { margin: 8px 0 0; font-size: 13px; min-height: 18px; }
.kt-msg.ok { color: #8ef0b8; } .kt-msg.err { color: #ffb0a6; }

/* ---------- CTA ---------- */
.kt-cta { display: grid; grid-template-columns: auto 1fr auto; gap: 24px; align-items: center; margin: 0 var(--gutter); padding: 28px 0; }
.kt-cta-ico { width: 70px; height: 70px; border-radius: 18px; display: grid; place-items: center; font-size: 36px; color: #fff; background: linear-gradient(135deg, #2b86ff, #0b3a8e); box-shadow: 0 16px 30px -16px rgba(20,103,230,.8); transform: perspective(400px) rotateY(-14deg); }
.kt-cta h2 { font-size: clamp(19px, 1.8vw, 24px); margin: 0 0 4px; }
.kt-cta p { margin: 0; color: var(--b-muted); }
.kt-cta-btns { display: flex; gap: 12px; flex-wrap: wrap; }

/* ---------- Article page ---------- */
.bv { padding: 108px var(--gutter) 20px; }
.bv-loading { padding: 80px 0; text-align: center; color: var(--b-muted); }
.bv-crumb { display: flex; gap: 8px; font-size: 13px; color: var(--b-muted); margin-bottom: 16px; flex-wrap: wrap; }
.bv-crumb a:hover { color: var(--b-blue); }
.bv-wrap { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 40px; align-items: start; }
.bv h1 { font-size: clamp(28px, 3.2vw, 42px); line-height: 1.2; margin: 12px 0 14px; }
.bv-lead { font-size: 17px; color: var(--b-muted); margin: 0 0 20px; }
.bv-cover { border-radius: 16px; overflow: hidden; margin: 22px 0 28px; aspect-ratio: 16 / 8; }
.bv-cover img { width: 100%; height: 100%; object-fit: cover; }
.bv-body { font-size: 16.5px; line-height: 1.8; color: #24324a; }
.bv-body h2 { font-size: 24px; margin: 34px 0 12px; scroll-margin-top: 90px; }
.bv-body h3 { font-size: 19px; margin: 26px 0 10px; }
.bv-body a { color: var(--b-blue); text-decoration: underline; text-underline-offset: 3px; }
.bv-body img { border-radius: 12px; margin: 18px 0; }
.bv-body blockquote { margin: 22px 0; padding: 14px 20px; border-left: 4px solid var(--b-blue); background: #eef4ff; border-radius: 0 12px 12px 0; color: var(--b-ink); }
.bv-body ul, .bv-body ol { padding-left: 22px; }
.bv-tags { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 26px; }
.bv-tags span { padding: 4px 12px; border-radius: 99px; background: #e8f0fd; color: var(--b-blue); font-size: 12.5px; }
.bv-side { position: sticky; top: 90px; display: grid; gap: 16px; }
.bv-box { background: #fff; border: 1px solid var(--b-line); border-radius: 14px; padding: 18px; }
.bv-box h4 { margin: 0 0 10px; font: 700 14px var(--display); color: var(--b-ink); }
.bv-toc { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; font-size: 13.5px; }
.bv-toc a { color: var(--b-muted); }
.bv-toc a:hover, .bv-toc a.on { color: var(--b-blue); }
.bv-share { display: flex; gap: 8px; }
.bv-share button, .bv-share a { width: 38px; height: 38px; border-radius: 50%; border: 1px solid var(--b-line); background: #fff; display: grid; place-items: center; color: var(--b-ink); }
.bv-share button:hover, .bv-share a:hover { border-color: var(--b-blue); color: var(--b-blue); }
.bv-preview { position: fixed; left: 50%; top: 72px; transform: translateX(-50%); z-index: 60; background: #fff4d6; color: #7a5300; border: 1px solid #f0d58a; padding: 6px 16px; border-radius: 99px; font: 600 13px var(--display); }

/* ---------- Responsive ---------- */
@media (max-width: 1100px) {
  .kt-grid { grid-template-columns: repeat(2, 1fr); }
  .kt-steps { grid-template-columns: repeat(2, 1fr); }
  .kt-popular { grid-template-columns: repeat(2, 1fr); }
  .kt-hero { grid-template-columns: 1fr; }
  .bv-wrap { grid-template-columns: 1fr; }
  .bv-side { position: static; }
}
@media (max-width: 820px) {
  .kt-featured, .kt-news { grid-template-columns: 1fr; }
  .kt-news-art { display: none; }
  .kt-filter { position: static; flex-direction: column; align-items: stretch; margin-top: -16px; }
  .kt-tabs { flex-wrap: nowrap; overflow-x: auto; scrollbar-width: none; }
  .kt-tabs button { flex: none; }
  .kt-search { min-width: 0; }
  .kt-head { flex-direction: column; align-items: flex-start; gap: 8px; }
  .kt-head h2 small { display: block; margin: 4px 0 0; }
  .kt-cta { grid-template-columns: 1fr; text-align: left; }
  .kt-hero-points { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  .kt-grid, .kt-steps, .kt-popular { grid-template-columns: 1fr; }
  .kt-hero-art { grid-template-columns: 1fr; }
  .kt-hcard.big { min-height: 260px; }
  .kt-hero-next { display: none; }
  .kt-feat-row { grid-template-columns: 1fr; }
  .kt-feat-row img { height: 170px; }
  .kt-feat-big { min-height: 320px; padding: 20px; }
  .bv-body { font-size: 15.5px; }
}