/* hello.bongwork.com — landing giới thiệu Bống Hub.
   Màu/chữ/thang khớp 08-Brand/design-system/BRAND_KIT.md: navy + teal, không màu thứ ba, không gradient. */
:root {
  --navy-950: #04122f; --navy-900: #061a42; --navy-800: #082054; --navy-700: #0d2c6c;
  --navy-300: #8aa4d8; --navy-200: #c2d0ea; --navy-100: #e3e9f6; --navy-50: #f2f5fb;
  --teal-700: #007b99; --teal-600: #0093b5; --teal-500: #00a9cc; --teal-300: #7ed3e8; --teal-100: #e0f4fa;
  --gray-900: #141a24; --gray-600: #4d5768; --gray-500: #6b7688; --gray-50: #f7f8fb;

  --bg: var(--gray-50); --fg: var(--gray-900); --heading: var(--navy-900); --muted: var(--gray-600);
  --line: var(--navy-100); --card: #fff;
  --font-sans: "Be Vietnam Pro", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --wrap: 1200px; --gutter: 16px;
  --r-control: 10px; --r-card: 20px; --r-bubble: 18px;
  --shadow-1: 0 1px 2px rgba(8,32,84,.06), 0 4px 12px -4px rgba(8,32,84,.08);
  --shadow-2: 0 2px 4px rgba(8,32,84,.06), 0 16px 32px -12px rgba(8,32,84,.18);
  --ease: cubic-bezier(.2,.8,.26,1);
}
@media (min-width: 640px) { :root { --gutter: 24px; } }

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; scroll-padding-top: 76px; }
body {
  margin: 0; background: var(--bg); color: var(--fg); overflow-x: clip;
  font: 400 16px/1.62 var(--font-sans); -webkit-font-smoothing: antialiased; text-wrap: pretty;
}
img, video { max-width: 100%; display: block; }
[hidden] { display: none !important; }
a { color: var(--teal-700); }
h1, h2, h3, p, ul, ol, dl, dd, figure { margin: 0; }
ul, ol { padding: 0; list-style: none; }
h1, h2, h3 { color: var(--heading); text-wrap: balance; letter-spacing: -0.02em; }
h1 { font-size: clamp(36px, 7vw, 56px); font-weight: 800; line-height: 1.2; }
h2 { font-size: clamp(26px, 4.2vw, 36px); font-weight: 700; line-height: 1.22; }
h3 { font-size: 18px; font-weight: 600; line-height: 1.35; letter-spacing: -0.01em; }
.mono { font-family: var(--font-mono); font-weight: 500; font-variant-numeric: tabular-nums; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
.sprite { position: absolute; width: 0; height: 0; overflow: hidden; }
.ic { width: 20px; height: 20px; flex: none; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
:focus-visible { outline: 3px solid var(--teal-500); outline-offset: 3px; border-radius: 6px; }

.wrap { max-width: var(--wrap); margin-inline: auto; padding-inline: var(--gutter); }
.sect { padding-block: 56px; }
@media (min-width: 900px) { .sect { padding-block: 96px; } }
.sect-white { background: #fff; }
.sect-navy { background: var(--navy-800); color: var(--navy-100); }
.sect-navy h2, .sect-navy h3 { color: #fff; }
.sect-head { max-width: 44rem; margin-bottom: 28px; }
@media (min-width: 900px) { .sect-head { margin-bottom: 40px; } }
.lead { margin-top: 14px; font-size: clamp(17px, 2.2vw, 19px); color: var(--muted); max-width: 68ch; }
.lead-onnavy { color: var(--navy-200); }
.note { margin-top: 20px; font-size: 14px; color: var(--gray-500); max-width: 68ch; }
.note-center { margin-inline: auto; text-align: center; }
.eyebrow { font: 500 12px/1.5 var(--font-mono); letter-spacing: .12em; text-transform: uppercase; color: var(--teal-700); margin-bottom: 14px; }
.eyebrow-onnavy { color: var(--teal-300); }

.skip { position: absolute; left: 12px; top: -60px; z-index: 50; padding: 10px 16px; background: #fff; color: var(--navy-800); border-radius: var(--r-control); font-weight: 600; }
.skip:focus { top: 12px; }

/* ---- Nút ---- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 52px; padding: 0 24px; border-radius: 999px; border: 0; cursor: pointer;
  font: 600 16px/1.2 var(--font-sans); text-decoration: none; text-align: center;
  transition: background-color 140ms var(--ease), transform 140ms var(--ease), border-color 140ms var(--ease);
}
.btn:active { transform: translateY(1px); }
.btn-sm { min-height: 40px; padding: 0 16px; font-size: 14px; }
.btn-block { width: 100%; }
.btn-teal { background: var(--teal-500); color: var(--navy-950); }
.btn-teal:hover { background: var(--teal-300); }
.btn-navy { background: var(--navy-800); color: #fff; }
.btn-navy:hover { background: var(--navy-700); }
.btn-ghost { background: transparent; color: #fff; border: 1.5px solid rgba(194,208,234,.4); }
.btn-ghost:hover { border-color: var(--navy-200); background: rgba(255,255,255,.06); }
.btn-onnavy { background: #fff; color: var(--navy-800); }
.btn-onnavy:hover { background: var(--navy-100); }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.cta-center { justify-content: center; }
@media (max-width: 479px) { .cta-row .btn { width: 100%; } }

/* ---- Header ---- */
.top { position: sticky; top: 0; z-index: 30; background: var(--navy-950); border-bottom: 1px solid rgba(194,208,234,.1); }
.top-in { display: flex; align-items: center; gap: 16px; min-height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; color: #fff; text-decoration: none; font-weight: 700; font-size: 17px; line-height: 1.2; }
.brand img { width: 36px; height: 36px; border-radius: 9px; }
.brand small { display: block; font-weight: 500; font-size: 12px; color: var(--navy-300); }
.top-nav { display: none; gap: 4px; margin-left: auto; }
.top-nav a { color: var(--navy-200); text-decoration: none; font-size: 15px; font-weight: 500; padding: 8px 12px; border-radius: var(--r-control); transition: color 140ms var(--ease); }
.top-nav a:hover { color: #fff; }
.top .btn { margin-left: auto; }
/* Mobile: CTA ở hero + thanh dính đáy đã đủ — bỏ nút trên header để khỏi hai nút giống nhau cùng màn. */
@media (max-width: 899px) { .top .btn { display: none; } }
@media (min-width: 900px) { .top-nav { display: flex; } .top .btn { margin-left: 8px; } }

/* ---- Hero ---- */
.hero { background: var(--navy-950); color: var(--navy-100); padding-block: 40px 56px; }
.hero h1 { color: #fff; }
.hero-in { display: grid; gap: 36px; align-items: center; }
.hero-sub { margin-top: 18px; font-size: clamp(17px, 2.3vw, 19px); color: var(--navy-200); max-width: 34em; }
.next { margin-top: 16px; font-size: 15px; color: var(--navy-300); max-width: 34em; }
@media (min-width: 900px) {
  .hero { padding-block: 72px 96px; }
  .hero-in { grid-template-columns: minmax(0, 5fr) minmax(0, 6fr); gap: 56px; }
}

.video-frame {
  position: relative; aspect-ratio: 16 / 9; border-radius: var(--r-card); overflow: hidden;
  background: var(--navy-900) url("../assets/video/poster-720.jpg") center / cover no-repeat;
  border: 1px solid rgba(194,208,234,.14);
  box-shadow: 0 24px 48px -20px rgba(0,0,0,.6);
}
@media (min-width: 900px) { .video-frame { background-image: url("../assets/video/poster-1080.jpg"); } }
.hero-video { width: 100%; height: 100%; object-fit: cover; }
.video-ctrl { position: absolute; right: 12px; bottom: 12px; display: flex; gap: 8px; }
.vbtn {
  display: grid; place-items: center; width: 44px; height: 44px; border-radius: 999px; cursor: pointer;
  border: 1px solid rgba(194,208,234,.3); background: rgba(4,18,47,.72); color: #fff;
  transition: background-color 140ms var(--ease);
}
.vbtn:hover { background: var(--navy-800); }
.vbtn .ic { width: 18px; height: 18px; }
.vbtn[data-act="play"] .ic { fill: currentColor; stroke: none; }
.video-frame[data-state="paused"] .vbtn[data-act="play"] { width: 56px; height: 56px; }

/* ---- Card + lưới ---- */
.grid { display: grid; gap: 16px; }
@media (min-width: 640px) { .g2, .g3 { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (min-width: 900px) { .g3 { grid-template-columns: repeat(3, minmax(0, 1fr)); } .grid { gap: 20px; } }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--r-card); padding: 24px; box-shadow: var(--shadow-1); }
.card h3 + p { margin-top: 8px; }
.card p { color: var(--muted); }
.ic-box { display: inline-grid; place-items: center; width: 44px; height: 44px; border-radius: 12px; background: var(--navy-50); color: var(--navy-800); margin-bottom: 16px; }
.ic-box .ic { width: 22px; height: 22px; }

/* ---- Ba việc thử ---- */
.try { display: flex; flex-direction: column; }
.try h3 { margin-top: 0; }
.try .say {
  margin-top: 14px; padding: 12px 16px; border-radius: var(--r-bubble) var(--r-bubble) var(--r-bubble) 6px;
  background: var(--navy-50); color: var(--navy-900) !important; font-size: 15.5px; font-weight: 500;
}
.then { margin-top: 12px; font-size: 15px; }
@media (max-width: 639px) {
  .card { padding: 20px; }
  .try { display: grid; grid-template-columns: 44px minmax(0, 1fr); column-gap: 14px; align-items: center; }
  .try .ic-box { margin-bottom: 0; }
  .try .say, .try .then { grid-column: 1 / -1; }
}

.step { display: flex; gap: 16px; align-items: flex-start; }
.step p { color: var(--fg); font-weight: 500; font-size: 17px; }
.step-n { flex: none; display: grid; place-items: center; width: 40px; height: 40px; border-radius: 999px; background: var(--navy-800); color: #fff; font-size: 17px; }
#ket-noi .cta-row { margin-top: 32px; }

/* ---- Kiểm soát (nền navy) ---- */
.card-navy { background: var(--navy-900); border-color: rgba(194,208,234,.14); box-shadow: none; }
.card-navy p { color: var(--navy-200); }
.ic-box-navy { background: rgba(126,211,232,.1); color: var(--teal-300); }

/* ---- FAQ ---- */
.faq-in .sect-head, .faq { max-width: 760px; margin-inline: auto; }
.faq { display: grid; gap: 12px; }
.faq details { background: #fff; border: 1px solid var(--line); border-radius: 14px; }
.faq summary {
  display: flex; align-items: center; justify-content: space-between; gap: 16px; cursor: pointer;
  padding: 18px 20px; font-weight: 600; color: var(--heading); list-style: none; min-height: 56px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary .ic { color: var(--navy-300); transition: transform 200ms var(--ease); }
.faq details[open] summary .ic { transform: rotate(45deg); }
.faq details p { padding: 0 20px 20px; color: var(--muted); }

/* ---- CTA cuối + footer ---- */
.final-in { text-align: center; max-width: 760px; }
.final-in .lead { margin-inline: auto; }
.final-mascot { width: 112px; height: auto; margin: 0 auto 12px; }
.foot { background: var(--navy-950); color: var(--navy-300); padding-block: 28px 96px; font-size: 14px; }
@media (min-width: 900px) { .foot { padding-bottom: 28px; } }
.foot-in { display: flex; flex-wrap: wrap; gap: 8px 24px; justify-content: space-between; }
.foot strong { color: #fff; }
.foot a { color: var(--teal-300); }
.foot .note { margin: 0; color: var(--navy-300); }

/* ---- Thanh CTA dính đáy (mobile) ---- */
.dock {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 40;
  padding: 12px var(--gutter) calc(12px + env(safe-area-inset-bottom));
  background: var(--navy-950); border-top: 1px solid rgba(194,208,234,.14);
  transition: transform 200ms var(--ease), opacity 200ms var(--ease), visibility 0s;
}
.dock[data-show="0"] { transform: translateY(100%); opacity: 0; visibility: hidden; transition-delay: 0s, 0s, 200ms; }
@media (min-width: 900px) { .dock { display: none !important; } }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: 0ms !important; animation: none !important; }
}

/* ---- 404 ---- */
.page-404 { min-height: 100vh; display: grid; place-items: center; }
.page-404 h1 { color: #fff; font-size: clamp(28px, 5vw, 40px); }