/* ══════════════════════════════════════════════════════════
   LA BÀN TÀI CHÍNH — Blog tài chính cá nhân
   Identity: CLEAN-CORPORATE | Font: Outfit (heading 600 + body)
   Nav: Nav-6 Full-Width Dark Bar | Hero: H2 Split 45/55 (carousel)
   Accent: Moss Green #4f7a34 (hue ~97°, khác dải xanh dương/teal/tím
   đã dùng ở các site CLEAN-CORPORATE khác) | Prefix: btc-
   ══════════════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700&display=swap');

:root {
  --bg: #f6f7f2;
  --surface: #ffffff;
  --dark: #101b14;
  --dark2: #16241c;
  --border: #dbe2d4;
  --border-light: #ecefe6;
  --text: #142018;
  --text-2: #4f5d51;
  --text-3: #8a9a8c;
  --accent: #4f7a34;
  --accent-h: #3c5e27;
  --accent-light: #e9f0e0;
  --accent-mid: #7a9c5a;
  --gold: #c9932f;
  --gold-light: #faf1de;
  --danger: #c1443a;
  --danger-light: #f8e8e6;
  --sans: 'Outfit', sans-serif;
  --radius: 8px;
  --radius-lg: 14px;
  --nav-h: 76px;
}

/* ── Reset / Base ─────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--sans);
  font-size: 15.5px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
h1, h2, h3, h4, h5, h6 { margin: 0; font-weight: 600; color: var(--text); line-height: 1.22; letter-spacing: -.3px; }
p { margin: 0; }
a { color: inherit; text-decoration: none; }
ul, ol { margin: 0; padding: 0; }
img { display: block; max-width: 100%; height: auto; }
button { font-family: var(--sans); cursor: pointer; border: none; background: none; }
input, select, textarea { font-family: var(--sans); }
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }

.wd-container { max-width: 1120px; margin: 0 auto; padding: 0 clamp(20px,5vw,60px); }
.btc-sec { padding: clamp(60px,8vw,104px) 0; }
.btc-sec-sm { padding: clamp(36px,5vw,56px) 0; }
.btc-sec-dark { background: var(--dark2); color: rgba(255,255,255,.82); }
.btc-sec-tint { background: var(--accent-light); }

/* ── Reveal animation ─────────────────────────────────────── */
[data-reveal] { opacity: 0; transform: translateY(26px); transition: opacity .7s cubic-bezier(.16,1,.3,1), transform .7s cubic-bezier(.16,1,.3,1); }
[data-reveal].visible { opacity: 1; transform: none; }
[data-reveal][data-delay="1"] { transition-delay: .08s; }
[data-reveal][data-delay="2"] { transition-delay: .16s; }
[data-reveal][data-delay="3"] { transition-delay: .24s; }
[data-reveal][data-delay="4"] { transition-delay: .32s; }

/* ── Section header ───────────────────────────────────────── */
.btc-tag { display: inline-flex; align-items: center; gap: 8px; font-size: 12px; font-weight: 600; text-transform: uppercase; letter-spacing: 1.6px; color: var(--accent); margin-bottom: 14px; }
.btc-tag::before { content: ''; width: 22px; height: 2px; background: var(--accent); border-radius: 2px; }
.btc-h2 { font-size: clamp(26px,3.2vw,38px); }
.btc-h2 em { color: var(--accent); font-style: normal; }
.btc-sub { font-size: 15.5px; font-weight: 300; color: var(--text-2); max-width: 560px; margin-top: 12px; }
.btc-head-row { display: flex; justify-content: space-between; align-items: flex-end; gap: 20px; flex-wrap: wrap; margin-bottom: 40px; }
.btc-head-link { font-size: 13.5px; font-weight: 600; color: var(--accent); display: inline-flex; align-items: center; gap: 6px; white-space: nowrap; }
.btc-head-link svg { width: 15px; height: 15px; transition: transform .2s; }
.btc-head-link:hover svg { transform: translateX(3px); }

/* ── Buttons (CLEAN-CORP: radius 4px, solid, hover darken) ─── */
.btc-btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; font-family: var(--sans); font-size: 14px; font-weight: 600; padding: 13px 26px; border-radius: 4px; transition: all .2s; cursor: pointer; white-space: nowrap; }
.btc-btn-primary { background: var(--accent); color: #fff; }
.btc-btn-primary:hover { background: var(--accent-h); }
.btc-btn-white { background: #fff; color: var(--dark2); }
.btc-btn-white:hover { background: var(--accent-light); color: var(--accent-h); }
.btc-btn-outline { background: transparent; border: 1.5px solid rgba(255,255,255,.32); color: rgba(255,255,255,.9); }
.btc-btn-outline:hover { background: rgba(255,255,255,.1); border-color: rgba(255,255,255,.55); }
.btc-btn-ghost { background: transparent; border: 1.5px solid var(--border); color: var(--text-2); }
.btc-btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btc-btn-sm { padding: 9px 18px; font-size: 13px; }
.btc-btn-block { width: 100%; }

/* ══ NAV — Nav-6 Full-Width Dark Bar ══ */
#nav { position: fixed; top: 0; left: 0; right: 0; z-index: 900; height: var(--nav-h); background: var(--dark2); border-bottom: 1px solid rgba(255,255,255,.07); }
.btc-nav-inner { height: 100%; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.btc-logo { display: flex; align-items: center; gap: 10px; font-size: 18px; font-weight: 700; color: #fff; letter-spacing: -.4px; flex-shrink: 0; }
.btc-logo-mark { width: 34px; height: 34px; border-radius: 8px; background: var(--accent); display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.btc-logo-mark svg { width: 18px; height: 18px; color: #fff; }
.btc-logo span { color: var(--accent-mid); }
.btc-nav-links { display: flex; align-items: center; gap: 30px; }
.btc-nav-links a { font-size: 14px; font-weight: 500; color: rgba(255,255,255,.55); transition: color .2s; position: relative; }
.btc-nav-links a:hover, .btc-nav-links a.active { color: #fff; }
.btc-nav-links a.active::after { content: ''; position: absolute; left: 0; right: 0; bottom: -26px; height: 2px; background: var(--accent-mid); }
.btc-nav-cta { display: flex; align-items: center; gap: 14px; flex-shrink: 0; }
.btc-nav-search-btn { width: 38px; height: 38px; border-radius: 50%; background: rgba(255,255,255,.08); display: flex; align-items: center; justify-content: center; color: rgba(255,255,255,.7); transition: background .2s; }
.btc-nav-search-btn:hover { background: rgba(255,255,255,.16); }
.btc-nav-search-btn svg { width: 17px; height: 17px; }
.btc-nav-burger { display: none; flex-direction: column; justify-content: center; gap: 5px; width: 34px; height: 34px; }
.btc-nav-burger span { display: block; width: 22px; height: 2px; background: #fff; border-radius: 2px; transition: all .3s; }
.btc-nav-burger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.btc-nav-burger.open span:nth-child(2) { opacity: 0; }
.btc-nav-burger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
.btc-nav-mob { position: fixed; inset: 0; top: var(--nav-h); background: var(--dark2); z-index: 850; display: flex; flex-direction: column; padding: 28px clamp(20px,5vw,60px); gap: 6px; transform: translateY(-12px); opacity: 0; pointer-events: none; transition: all .3s; }
.btc-nav-mob.open { transform: translateY(0); opacity: 1; pointer-events: auto; }
.btc-nav-mob a { font-size: 18px; font-weight: 500; color: rgba(255,255,255,.8); padding: 14px 4px; border-bottom: 1px solid rgba(255,255,255,.08); }
.btc-nav-mob a.active { color: var(--accent-mid); }
.btc-nav-mob .btc-btn { margin-top: 18px; }
@media (max-width: 900px) { .btc-nav-links { display: none; } .btc-nav-search-btn { display: none; } .btc-nav-burger { display: flex; } }

/* ══ HERO CAROUSEL — H2 Split 45/55 ══ */
.btc-hero { position: relative; height: 100vh; min-height: 600px; overflow: hidden; background: var(--dark2); }
.btc-hero-slide { position: absolute; inset: 0; display: flex; opacity: 0; visibility: hidden; transition: opacity .8s ease; }
.btc-hero-slide.active { opacity: 1; visibility: visible; z-index: 2; }
.btc-hero-left { width: 45%; background: linear-gradient(155deg, var(--dark2) 0%, #0b130d 100%); display: flex; flex-direction: column; justify-content: center; padding: var(--nav-h) clamp(28px,5vw,72px) 0; position: relative; }
.btc-hero-left::before { content: ''; position: absolute; right: -80px; top: 20%; width: 220px; height: 220px; border-radius: 50%; background: radial-gradient(circle, rgba(122,156,90,.22), transparent 70%); }
.btc-hero-right { width: 55%; position: relative; }
.btc-hero-right img { width: 100%; height: 100%; object-fit: cover; }
.btc-hero-right::after { content: ''; position: absolute; inset: 0; background: linear-gradient(90deg, rgba(16,27,20,.35), transparent 30%); }
.btc-hero-label { font-size: 13px; font-weight: 600; text-transform: uppercase; letter-spacing: 2px; color: var(--accent-mid); margin-bottom: 18px; position: relative; z-index: 2; }
.btc-hero-title { font-size: clamp(34px,4vw,54px); color: #fff; font-weight: 600; letter-spacing: -1px; line-height: 1.14; position: relative; z-index: 2; }
.btc-hero-title em { color: var(--accent-mid); font-style: normal; }
.btc-hero-desc { font-size: 16px; font-weight: 300; color: rgba(255,255,255,.62); margin-top: 20px; max-width: 420px; line-height: 1.7; position: relative; z-index: 2; }
.btc-hero-cta { display: flex; gap: 14px; margin-top: 32px; flex-wrap: wrap; position: relative; z-index: 2; }
.btc-hero-nav { position: absolute; top: 50%; transform: translateY(-50%); z-index: 5; width: 52px; height: 52px; border-radius: 50%; background: rgba(255,255,255,.12); backdrop-filter: blur(10px); border: 1px solid rgba(255,255,255,.2); display: flex; align-items: center; justify-content: center; color: #fff; transition: background .2s; }
.btc-hero-nav:hover { background: rgba(255,255,255,.24); }
.btc-hero-nav svg { width: 20px; height: 20px; }
.btc-hero-prev { left: clamp(16px,3vw,40px); }
.btc-hero-next { right: clamp(16px,3vw,40px); }
.btc-hero-dots { position: absolute; bottom: 32px; left: 45%; transform: translateX(-50%); z-index: 5; display: flex; gap: 10px; }
.btc-hero-dot { width: 9px; height: 9px; border-radius: 50%; background: rgba(255,255,255,.32); transition: all .25s; }
.btc-hero-dot.active { background: var(--accent-mid); width: 26px; border-radius: 5px; }
@media (max-width: 900px) {
  .btc-hero { height: 90vh; }
  .btc-hero-slide { flex-direction: column; }
  .btc-hero-left { width: 100%; height: 58%; padding: calc(var(--nav-h) + 20px) 24px 20px; }
  .btc-hero-right { width: 100%; height: 42%; }
  .btc-hero-dots { left: 50%; }
  .btc-hero-desc { max-width: 100%; }
}
@media (max-width: 480px) { .btc-hero-title { font-size: 30px; } .btc-hero-cta { flex-direction: column; } .btc-hero-cta .btc-btn { width: 100%; } }

/* ── Page header (inner pages) ───────────────────────────── */
.btc-page-header { position: relative; padding: clamp(110px,15vw,160px) 0 clamp(48px,7vw,72px); background: var(--dark2); overflow: hidden; }
.btc-page-header::before { content: ''; position: absolute; inset: 0; background-size: cover; background-position: center; opacity: .22; }
.btc-page-header-in { position: relative; z-index: 2; }
.btc-page-header .btc-tag { color: var(--accent-mid); }
.btc-page-header .btc-tag::before { background: var(--accent-mid); }
.btc-page-header h1 { color: #fff; font-size: clamp(28px,4vw,44px); }
.btc-page-header p { color: rgba(255,255,255,.6); margin-top: 12px; max-width: 580px; font-weight: 300; }
.btc-breadcrumb { display: flex; gap: 8px; align-items: center; font-size: 13px; color: rgba(255,255,255,.5); margin-bottom: 18px; position: relative; z-index: 2; }
.btc-breadcrumb a { color: rgba(255,255,255,.5); }
.btc-breadcrumb a:hover { color: #fff; }

/* ══ STAT-BAR ══ */
.btc-stats-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: clamp(32px,6vw,60px); text-align: center; }
.btc-stat-num { font-size: clamp(30px,3.6vw,44px); font-weight: 700; color: var(--accent-mid); letter-spacing: -1px; }
.btc-stat-label { font-size: 13px; color: rgba(255,255,255,.55); margin-top: 8px; }
@media (max-width: 1024px) { .btc-stats-grid { grid-template-columns: repeat(2,1fr); } }
@media (max-width: 640px) { .btc-stats-grid { grid-template-columns: 1fr; } }

/* ══ BENTO-GRID — bài viết nổi bật ══ */
.btc-bento { display: grid; grid-template-columns: 1.5fr 1fr; grid-template-rows: auto auto; gap: 22px; }
.btc-bento-main { grid-row: span 2; }
.btc-post-card { display: block; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; height: 100%; transition: border-color .2s, box-shadow .2s, transform .2s; }
.btc-post-card:hover { border-color: var(--accent); box-shadow: 0 14px 40px rgba(20,32,24,.08); transform: translateY(-3px); }
.btc-bento-main .btc-post-thumb { aspect-ratio: 16/11; }
.btc-post-thumb { width: 100%; aspect-ratio: 16/10; overflow: hidden; position: relative; }
.btc-post-thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s; }
.btc-post-card:hover .btc-post-thumb img { transform: scale(1.05); }
.btc-post-cat { position: absolute; top: 14px; left: 14px; background: rgba(16,27,20,.75); backdrop-filter: blur(6px); color: #fff; font-size: 11px; font-weight: 600; text-transform: uppercase; letter-spacing: .8px; padding: 5px 11px; border-radius: 4px; }
.btc-post-body { padding: 22px; }
.btc-bento-main .btc-post-body { padding: 26px 28px; }
.btc-post-title { font-size: 16px; font-weight: 600; line-height: 1.4; letter-spacing: -.2px; }
.btc-bento-main .btc-post-title { font-size: clamp(20px,2vw,26px); }
.btc-post-card:hover .btc-post-title { color: var(--accent); }
.btc-post-excerpt { font-size: 13.5px; font-weight: 300; color: var(--text-2); margin-top: 10px; line-height: 1.65; }
.btc-post-meta { display: flex; align-items: center; gap: 10px; margin-top: 16px; font-size: 12px; color: var(--text-3); }
.btc-post-meta img { width: 24px; height: 24px; border-radius: 50%; object-fit: cover; }
.btc-bento-side { display: flex; flex-direction: column; gap: 22px; }
.btc-bento-side .btc-post-card { display: flex; flex-direction: row; align-items: stretch; }
.btc-bento-side .btc-post-thumb { width: 120px; aspect-ratio: auto; flex-shrink: 0; }
.btc-bento-side .btc-post-body { padding: 14px 16px; flex: 1; }
.btc-bento-side .btc-post-title { font-size: 14px; }
.btc-bento-side .btc-post-excerpt { display: none; }
@media (max-width: 900px) { .btc-bento { grid-template-columns: 1fr; } .btc-bento-main { grid-row: auto; } }
@media (max-width: 560px) { .btc-bento-side .btc-post-card { flex-direction: column; } .btc-bento-side .btc-post-thumb { width: 100%; aspect-ratio: 16/10; } }

/* ══ FEATURE-ICON-ROW — chuyên mục ══ */
.btc-cat-row { display: grid; grid-template-columns: repeat(6,1fr); gap: 18px; }
.btc-cat-item { display: flex; flex-direction: column; align-items: center; text-align: center; gap: 14px; padding: 26px 14px; border-radius: var(--radius); transition: background .2s, transform .2s; }
.btc-cat-item:hover { background: var(--surface); transform: translateY(-4px); box-shadow: 0 10px 28px rgba(20,32,24,.06); }
.btc-cat-icon { width: 56px; height: 56px; border-radius: 14px; background: var(--accent-light); display: flex; align-items: center; justify-content: center; color: var(--accent); }
.btc-cat-icon svg { width: 26px; height: 26px; }
.btc-cat-name { font-size: 13.5px; font-weight: 600; }
.btc-cat-count { font-size: 11.5px; color: var(--text-3); }
@media (max-width: 992px) { .btc-cat-row { grid-template-columns: repeat(3,1fr); } }
@media (max-width: 560px) { .btc-cat-row { grid-template-columns: repeat(2,1fr); } }

/* ══ GRID-CARDS — bài viết mới nhất ══ */
.btc-grid-cards { display: grid; grid-template-columns: repeat(4,1fr); gap: 22px; }
@media (max-width: 1100px) { .btc-grid-cards { grid-template-columns: repeat(2,1fr); } }
@media (max-width: 560px) { .btc-grid-cards { grid-template-columns: 1fr; } }
.btc-grid-cards.btc-grid-3 { grid-template-columns: repeat(3,1fr); }
@media (max-width: 900px) { .btc-grid-cards.btc-grid-3 { grid-template-columns: repeat(2,1fr); } }
@media (max-width: 560px) { .btc-grid-cards.btc-grid-3 { grid-template-columns: 1fr; } }

/* ══ ALTERNATING-STRIPS — công cụ nổi bật ══ */
.btc-strip { display: flex; align-items: center; gap: clamp(30px,5vw,70px); }
.btc-strip.rev { flex-direction: row-reverse; }
.btc-strip-text { flex: 1; }
.btc-strip-visual { flex: 1; }
.btc-strip + .btc-strip { margin-top: clamp(50px,7vw,90px); }
.btc-tool-mock { background: var(--dark2); border-radius: var(--radius-lg); padding: 28px; color: #fff; box-shadow: 0 24px 60px rgba(16,27,20,.18); }
.btc-tool-mock-row { display: flex; justify-content: space-between; align-items: center; padding: 12px 0; border-bottom: 1px solid rgba(255,255,255,.08); font-size: 13.5px; }
.btc-tool-mock-row:last-child { border-bottom: none; }
.btc-tool-mock-row strong { color: var(--accent-mid); font-size: 15px; }
.btc-strip-list { margin-top: 22px; display: flex; flex-direction: column; gap: 12px; }
.btc-strip-list-item { display: flex; align-items: flex-start; gap: 12px; font-size: 14px; color: var(--text-2); }
.btc-strip-list-item svg { width: 18px; height: 18px; color: var(--accent); flex-shrink: 0; margin-top: 2px; }
@media (max-width: 860px) { .btc-strip, .btc-strip.rev { flex-direction: column; } }

/* ══ LIST-ELEGANT — nhận xét độc giả ══ */
.btc-testi-list { display: flex; flex-direction: column; }
.btc-testi-item { display: grid; grid-template-columns: 260px 1fr; gap: 40px; padding: 32px 0; border-bottom: 1px solid var(--border); }
.btc-testi-item:first-child { padding-top: 0; }
.btc-testi-item:last-child { border-bottom: none; }
.btc-testi-person { display: flex; align-items: center; gap: 14px; }
.btc-testi-person img { width: 52px; height: 52px; border-radius: 50%; object-fit: cover; }
.btc-testi-name { font-size: 14.5px; font-weight: 600; }
.btc-testi-role { font-size: 12.5px; color: var(--text-3); margin-top: 2px; }
.btc-testi-quote { font-size: 16px; font-weight: 300; color: var(--text); line-height: 1.7; font-style: italic; }
@media (max-width: 720px) { .btc-testi-item { grid-template-columns: 1fr; gap: 16px; } }

/* ══ FAQ accordion (custom — CLEAN-CORP) ══ */
.btc-faq-list { max-width: 780px; margin: 0 auto; }
.btc-faq-item { border-bottom: 1px solid var(--border); }
.btc-faq-item:first-child { border-top: 1px solid var(--border); }
.btc-faq-q { width: 100%; display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 22px 4px; text-align: left; font-size: 15.5px; font-weight: 600; color: var(--text); }
.btc-faq-q-icon { width: 30px; height: 30px; border-radius: 50%; border: 1.5px solid var(--border); display: flex; align-items: center; justify-content: center; flex-shrink: 0; transition: all .25s; color: var(--accent); }
.btc-faq-q-icon svg { width: 14px; height: 14px; transition: transform .25s; }
.btc-faq-item.open .btc-faq-q-icon { background: var(--accent); border-color: var(--accent); color: #fff; }
.btc-faq-item.open .btc-faq-q-icon svg { transform: rotate(135deg); }
.btc-faq-a { max-height: 0; overflow: hidden; transition: max-height .35s ease; }
.btc-faq-a-in { padding: 0 4px 24px; font-size: 14.5px; font-weight: 300; color: var(--text-2); line-height: 1.75; max-width: 680px; }

/* ══ CTA band ══ */
.btc-cta-band { background: var(--dark2); border-radius: var(--radius-lg); padding: clamp(40px,6vw,64px); display: flex; align-items: center; justify-content: space-between; gap: 30px; flex-wrap: wrap; position: relative; overflow: hidden; }
.btc-cta-band::before { content: ''; position: absolute; right: -60px; top: -60px; width: 240px; height: 240px; border-radius: 50%; background: radial-gradient(circle, rgba(122,156,90,.2), transparent 70%); }
.btc-cta-title { font-size: clamp(22px,2.6vw,30px); color: #fff; font-weight: 600; position: relative; z-index: 2; }
.btc-cta-title span { color: var(--accent-mid); }
.btc-cta-sub { font-size: 14px; font-weight: 300; color: rgba(255,255,255,.6); margin-top: 8px; position: relative; z-index: 2; }
.btc-cta-form { display: flex; gap: 10px; position: relative; z-index: 2; }
.btc-cta-form input { padding: 13px 18px; border-radius: 4px; border: 1px solid rgba(255,255,255,.18); background: rgba(255,255,255,.06); color: #fff; font-size: 14px; width: 240px; outline: none; }
.btc-cta-form input::placeholder { color: rgba(255,255,255,.4); }
.btc-cta-form input:focus { border-color: var(--accent-mid); }
@media (max-width: 640px) { .btc-cta-form { flex-direction: column; width: 100%; } .btc-cta-form input { width: 100%; } }

/* ══ Newsletter disclaimer note ══ */
.btc-disclaimer { display: flex; gap: 14px; align-items: flex-start; background: var(--gold-light); border: 1px solid #ecdcb4; border-radius: var(--radius); padding: 18px 20px; font-size: 13px; color: #7a5a15; }
.btc-disclaimer svg { width: 20px; height: 20px; flex-shrink: 0; color: var(--gold); margin-top: 1px; }

/* ══════════════════════════════════════════════════════════
   TRANG CHUYÊN MỤC — filter chips + masonry + horizontal scroll
   ══════════════════════════════════════════════════════════ */
.btc-filter-row { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 36px; }
.btc-filter-chip { padding: 10px 20px; border-radius: 20px; border: 1.5px solid var(--border); font-size: 13.5px; font-weight: 500; color: var(--text-2); transition: all .2s; }
.btc-filter-chip:hover { border-color: var(--accent); color: var(--accent); }
.btc-filter-chip.active { background: var(--accent); border-color: var(--accent); color: #fff; }

.btc-trending-scroll { display: flex; gap: 18px; overflow-x: auto; padding-bottom: 14px; scrollbar-width: thin; }
.btc-trending-scroll::-webkit-scrollbar { height: 6px; }
.btc-trending-card { flex: 0 0 260px; }
.btc-trending-num { position: absolute; top: 14px; left: 14px; width: 30px; height: 30px; border-radius: 50%; background: rgba(255,255,255,.92); color: var(--accent); font-weight: 700; font-size: 14px; display: flex; align-items: center; justify-content: center; z-index: 2; }

.btc-masonry { column-count: 3; column-gap: 22px; }
.btc-masonry .btc-post-card { break-inside: avoid; margin-bottom: 22px; }
.btc-masonry .tall .btc-post-thumb { aspect-ratio: 4/5; }
.btc-masonry .short .btc-post-thumb { aspect-ratio: 16/9; }
@media (max-width: 992px) { .btc-masonry { column-count: 2; } }
@media (max-width: 560px) { .btc-masonry { column-count: 1; } }

/* ══════════════════════════════════════════════════════════
   TRANG BÀI VIẾT CHI TIẾT
   ══════════════════════════════════════════════════════════ */
.btc-article-head { max-width: 820px; margin: 0 auto; text-align: center; position: relative; z-index: 2; }
.btc-article-head .btc-tag { justify-content: center; }
.btc-article-head h1 { color: #fff; font-size: clamp(28px,4vw,42px); }
.btc-article-meta-row { display: flex; align-items: center; justify-content: center; gap: 18px; margin-top: 22px; flex-wrap: wrap; }
.btc-article-author { display: flex; align-items: center; gap: 10px; }
.btc-article-author img { width: 38px; height: 38px; border-radius: 50%; object-fit: cover; }
.btc-article-author-name { font-size: 13.5px; font-weight: 600; color: #fff; }
.btc-article-meta-sep { color: rgba(255,255,255,.35); font-size: 13px; }
.btc-article-meta-item { font-size: 13px; color: rgba(255,255,255,.6); }

.btc-article-body { max-width: 720px; }
.btc-article-body h2 { font-size: 24px; margin-top: 44px; margin-bottom: 16px; }
.btc-article-body h3 { font-size: 19px; margin-top: 32px; margin-bottom: 12px; }
.btc-article-body p { font-size: 16px; font-weight: 300; color: var(--text-2); margin-bottom: 20px; line-height: 1.85; }
.btc-article-body p strong { color: var(--text); font-weight: 600; }
.btc-article-body ul, .btc-article-body ol { margin: 0 0 24px; padding-left: 22px; }
.btc-article-body li { font-size: 15.5px; font-weight: 300; color: var(--text-2); margin-bottom: 10px; line-height: 1.75; }
.btc-article-body ol { list-style: decimal; }
.btc-article-body ul { list-style: disc; }
.btc-article-body img.btc-inline-img { border-radius: var(--radius); margin: 32px 0; }
.btc-inline-cap { font-size: 12.5px; color: var(--text-3); text-align: center; margin-top: -20px; margin-bottom: 24px; }
.btc-blockquote { border-left: 3px solid var(--accent); background: var(--accent-light); border-radius: 0 var(--radius) var(--radius) 0; padding: 22px 26px; margin: 28px 0; font-size: 17px; font-weight: 500; color: var(--accent-h); font-style: italic; }
.btc-tags-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 40px; padding-top: 30px; border-top: 1px solid var(--border); }
.btc-article-tag { font-size: 12.5px; font-weight: 500; color: var(--text-2); background: var(--warm,var(--accent-light)); background: var(--border-light); padding: 7px 15px; border-radius: 20px; }
.btc-share-row { display: flex; align-items: center; gap: 14px; margin-top: 26px; }
.btc-share-label { font-size: 13px; color: var(--text-3); }
.btc-share-btn { width: 38px; height: 38px; border-radius: 50%; border: 1px solid var(--border); display: flex; align-items: center; justify-content: center; color: var(--text-2); transition: all .2s; }
.btc-share-btn:hover { border-color: var(--accent); color: var(--accent); }
.btc-share-btn svg { width: 16px; height: 16px; }

.btc-author-box { display: flex; gap: 20px; align-items: center; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 26px; margin-top: 44px; }
.btc-author-box img { width: 70px; height: 70px; border-radius: 50%; object-fit: cover; flex-shrink: 0; }
.btc-author-box-name { font-size: 15px; font-weight: 600; }
.btc-author-box-role { font-size: 12.5px; color: var(--accent); margin-top: 2px; }
.btc-author-box-desc { font-size: 13.5px; font-weight: 300; color: var(--text-2); margin-top: 8px; line-height: 1.6; }
@media (max-width: 560px) { .btc-author-box { flex-direction: column; text-align: center; } }

.btc-toc { position: sticky; top: calc(var(--nav-h) + 24px); background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 24px; }
.btc-toc-title { font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; color: var(--text-3); margin-bottom: 16px; }
.btc-toc-list { display: flex; flex-direction: column; gap: 12px; }
.btc-toc-list a { font-size: 13.5px; color: var(--text-2); padding-left: 14px; border-left: 2px solid var(--border); transition: all .2s; }
.btc-toc-list a:hover { color: var(--accent); border-color: var(--accent); }
.btc-sidebar-box { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 24px; margin-top: 24px; }
.btc-sidebar-box.btc-promo { background: var(--dark2); border: none; color: #fff; }
.btc-sidebar-box.btc-promo p { color: rgba(255,255,255,.62); font-size: 13px; font-weight: 300; margin: 10px 0 18px; }

/* ══════════════════════════════════════════════════════════
   TRANG CÔNG CỤ TÍNH TOÁN
   ══════════════════════════════════════════════════════════ */
.btc-tabs { display: flex; gap: 10px; margin-bottom: 36px; flex-wrap: wrap; border-bottom: 1px solid var(--border); }
.btc-tab-btn { padding: 14px 4px; margin-right: 30px; font-size: 15px; font-weight: 600; color: var(--text-3); border-bottom: 2px solid transparent; margin-bottom: -1px; transition: all .2s; }
.btc-tab-btn:hover { color: var(--text); }
.btc-tab-btn.active { color: var(--accent); border-color: var(--accent); }
.btc-tab-panel { display: none; }
.btc-tab-panel.active { display: block; }
.btc-calc-wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: start; }
.btc-calc-form { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 30px; }
.btc-field { margin-bottom: 20px; }
.btc-field label { display: block; font-size: 13px; font-weight: 600; color: var(--text-2); margin-bottom: 8px; }
.btc-field input, .btc-field select { width: 100%; padding: 12px 14px; border-radius: 6px; border: 1px solid var(--border); font-size: 14px; color: var(--text); background: var(--bg); outline: none; transition: border-color .2s; }
.btc-field input:focus, .btc-field select:focus { border-color: var(--accent); }
.btc-field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.btc-calc-result { background: var(--dark2); border-radius: var(--radius-lg); padding: 30px; color: #fff; }
.btc-result-main { text-align: center; padding-bottom: 24px; border-bottom: 1px solid rgba(255,255,255,.1); margin-bottom: 20px; }
.btc-result-label { font-size: 12.5px; color: rgba(255,255,255,.55); text-transform: uppercase; letter-spacing: 1px; }
.btc-result-value { font-size: clamp(28px,3vw,38px); font-weight: 700; color: var(--accent-mid); margin-top: 10px; letter-spacing: -1px; }
.btc-result-row { display: flex; justify-content: space-between; align-items: center; font-size: 13.5px; padding: 10px 0; color: rgba(255,255,255,.7); }
.btc-result-bar-wrap { margin-top: 20px; }
.btc-result-bar { height: 12px; border-radius: 6px; background: rgba(255,255,255,.12); overflow: hidden; display: flex; }
.btc-result-bar-seg { height: 100%; transition: width .5s ease; }
.btc-result-bar-legend { display: flex; justify-content: space-between; margin-top: 10px; font-size: 12px; color: rgba(255,255,255,.55); }
.btc-legend-dot { width: 8px; height: 8px; border-radius: 50%; display: inline-block; margin-right: 6px; }
@media (max-width: 860px) { .btc-calc-wrap { grid-template-columns: 1fr; } .btc-field-row { grid-template-columns: 1fr; } }

/* ══════════════════════════════════════════════════════════
   TRANG VỀ TÔI — timeline + values
   ══════════════════════════════════════════════════════════ */
.btc-timeline { position: relative; max-width: 720px; margin: 0 auto; }
.btc-timeline::before { content: ''; position: absolute; left: 20px; top: 8px; bottom: 8px; width: 2px; background: var(--border); }
.btc-timeline-item { position: relative; padding-left: 60px; margin-bottom: 40px; }
.btc-timeline-item:last-child { margin-bottom: 0; }
.btc-timeline-dot { position: absolute; left: 12px; top: 2px; width: 18px; height: 18px; border-radius: 50%; background: var(--surface); border: 3px solid var(--accent); }
.btc-timeline-year { font-size: 12.5px; font-weight: 700; color: var(--accent); text-transform: uppercase; letter-spacing: 1px; }
.btc-timeline-title { font-size: 16.5px; font-weight: 600; margin-top: 6px; }
.btc-timeline-desc { font-size: 14px; font-weight: 300; color: var(--text-2); margin-top: 8px; line-height: 1.7; }

.btc-value-row { display: grid; grid-template-columns: repeat(3,1fr); gap: 24px; }
.btc-value-item { text-align: center; padding: 8px; }
.btc-value-icon { width: 60px; height: 60px; border-radius: 16px; background: var(--accent-light); color: var(--accent); display: flex; align-items: center; justify-content: center; margin: 0 auto 18px; }
.btc-value-icon svg { width: 28px; height: 28px; }
.btc-value-title { font-size: 15.5px; font-weight: 600; }
.btc-value-desc { font-size: 13.5px; font-weight: 300; color: var(--text-2); margin-top: 8px; line-height: 1.65; }
@media (max-width: 720px) { .btc-value-row { grid-template-columns: 1fr; } }

/* ══════════════════════════════════════════════════════════
   TRANG LIÊN HỆ
   ══════════════════════════════════════════════════════════ */
.btc-contact-grid { display: grid; grid-template-columns: 1fr 1.15fr; gap: 50px; }
.btc-contact-info-item { display: flex; gap: 16px; padding: 20px 0; border-bottom: 1px solid var(--border); }
.btc-contact-info-item:first-child { padding-top: 0; }
.btc-contact-info-icon { width: 46px; height: 46px; border-radius: 12px; background: var(--accent-light); color: var(--accent); display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.btc-contact-info-icon svg { width: 20px; height: 20px; }
.btc-contact-info-label { font-size: 12px; color: var(--text-3); text-transform: uppercase; letter-spacing: .6px; }
.btc-contact-info-value { font-size: 14.5px; font-weight: 500; margin-top: 4px; }
.btc-form-box { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: clamp(26px,4vw,40px); }
.btc-form-box .btc-field input, .btc-form-box .btc-field select, .btc-form-box .btc-field textarea { width: 100%; padding: 13px 16px; border-radius: 6px; border: 1px solid var(--border); font-size: 14px; background: var(--bg); outline: none; transition: border-color .2s; }
.btc-form-box .btc-field textarea { resize: vertical; min-height: 120px; font-family: var(--sans); }
.btc-form-box .btc-field input:focus, .btc-form-box .btc-field textarea:focus { border-color: var(--accent); }
@media (max-width: 900px) { .btc-contact-grid { grid-template-columns: 1fr; } }

/* ══ Legal pages ══ */
.btc-legal-body { max-width: 760px; margin: 0 auto; }
.btc-legal-body h2 { font-size: 20px; margin-top: 36px; margin-bottom: 14px; }
.btc-legal-body p { font-size: 14.5px; font-weight: 300; color: var(--text-2); margin-bottom: 16px; line-height: 1.8; }
.btc-legal-body ul { padding-left: 20px; margin-bottom: 16px; }
.btc-legal-body li { font-size: 14.5px; font-weight: 300; color: var(--text-2); margin-bottom: 8px; line-height: 1.75; }

/* ══════════════════════════════════════════════════════════
   FOOTER — Light 4-col structured (CLEAN-CORP)
   ══════════════════════════════════════════════════════════ */
.btc-footer { background: var(--dark); color: rgba(255,255,255,.55); padding-top: clamp(60px,8vw,90px); }
.btc-footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.1fr; gap: 40px; padding-bottom: 50px; border-bottom: 1px solid rgba(255,255,255,.08); }
.btc-footer-logo { display: flex; align-items: center; gap: 10px; font-size: 18px; font-weight: 700; color: #fff; margin-bottom: 16px; }
.btc-footer-desc { font-size: 13.5px; font-weight: 300; line-height: 1.7; max-width: 280px; }
.btc-footer-social { display: flex; gap: 10px; margin-top: 20px; }
.btc-footer-social a { width: 36px; height: 36px; border-radius: 50%; background: rgba(255,255,255,.06); display: flex; align-items: center; justify-content: center; color: rgba(255,255,255,.6); transition: all .2s; }
.btc-footer-social a:hover { background: var(--accent); color: #fff; }
.btc-footer-social svg { width: 16px; height: 16px; }
.btc-footer-title { font-size: 13px; font-weight: 600; text-transform: uppercase; letter-spacing: 1px; color: #fff; margin-bottom: 20px; }
.btc-footer-links { display: flex; flex-direction: column; gap: 12px; }
.btc-footer-links a { font-size: 13.5px; transition: color .2s; }
.btc-footer-links a:hover { color: var(--accent-mid); }
.btc-footer-maps { width: 100%; height: 300px; border-radius: 12px; box-shadow: 0 4px 16px rgba(0,0,0,.1); overflow: hidden; margin-top: 44px; border: 1px solid rgba(255,255,255,.08); }
.btc-footer-maps iframe { width: 100%; height: 100%; border: 0; }
.btc-footer-bottom { display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; padding: 26px 0; font-size: 12.5px; }
.btc-footer-bottom-links { display: flex; gap: 20px; }
.btc-footer-bottom-links a:hover { color: #fff; }
@media (max-width: 900px) { .btc-footer-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px) { .btc-footer-grid { grid-template-columns: 1fr; } }

/* ══ Zalo float ══ */
.btc-zalo-float { position: fixed; bottom: 26px; right: 26px; width: 58px; height: 58px; border-radius: 50%; background: #0068FF; display: flex; align-items: center; justify-content: center; color: #fff; font-size: 26px; box-shadow: 0 8px 24px rgba(0,104,255,.35); z-index: 800; transition: transform .2s; }
.btc-zalo-float:hover { transform: scale(1.08); }

/* ══ Utility ══ */
.btc-center { text-align: center; }
.btc-mx-auto { margin-left: auto; margin-right: auto; }