/* ============================================================
   NAVISCHULE.COM — STYLES (mobile-first)
   Design tokens → base → components → sections → responsive → motion
   ============================================================ */

/* ---------- 1. DESIGN TOKENS ---------- */
:root {
  /* Màu — verify hex chuẩn theo navi-brand-kit khi có */
  --c-primary: #1B5FCB;
  --c-primary-dark: #0E3A8A;
  --c-primary-50: #EAF1FC;
  --c-accent: #F7821B;     /* CAM — chỉ dùng cho CTA chính */
  --c-accent-dark: #DA6C0A;
  --c-ink: #0F1B2D;        /* chữ chính */
  --c-ink-soft: #46556B;   /* chữ phụ */
  --c-line: #EDF1F7;
  --c-bg: #FFFFFF;
  --c-bg-alt: #F7FAFD;
  --c-ok: #1FA971;
  --c-no: #C2CBD8;

  /* Typography */
  --font: "Be Vietnam Pro", "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;

  /* Bo góc / shadow */
  --r-card: 22px;
  --r-btn: 12px;
  --r-pill: 999px;
  --shadow-sm: 0 6px 18px rgba(16,58,138,.05);
  --shadow: 0 14px 36px rgba(16,58,138,.08);
  --shadow-lg: 0 30px 70px rgba(16,58,138,.14);

  /* Spacing / layout */
  --wrap: 1180px;
  --wrap-narrow: 820px;
  --gap: 30px;
  --section-y: 76px;

  /* Motion */
  --ease: cubic-bezier(.22,.61,.36,1);
}

/* ---------- 2. BASE ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--c-ink);
  background: var(--c-bg);
  line-height: 1.75;
  font-size: 17px;
  overflow-x: hidden;
  padding-bottom: 84px; /* chừa chỗ cho sticky CTA mobile, reset ở ≥880 */
}
img, svg { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
h1, h2, h3 { line-height: 1.18; margin: 0 0 .5em; font-weight: 800; letter-spacing: -.025em; }
h1 { font-size: clamp(2.1rem, 5.4vw, 3.6rem); }
h2 { font-size: clamp(1.7rem, 3.8vw, 2.6rem); }
h3 { font-size: 1.18rem; }
p { margin: 0 0 1rem; color: var(--c-ink-soft); }
ul { margin: 0; padding: 0; list-style: none; }

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }
.section { padding: var(--section-y) 0; }
.section--alt { background: var(--c-bg-alt); }
.section__head { max-width: 680px; margin: 0 auto 56px; text-align: center; }
.section__head h2 { margin-bottom: .35em; }
.section__head p { font-size: 1.12rem; }
.eyebrow {
  display: inline-block; font-size: .78rem; font-weight: 700; letter-spacing: .1em;
  text-transform: uppercase; color: var(--c-primary); background: var(--c-primary-50);
  padding: 7px 16px; border-radius: var(--r-pill); margin-bottom: 18px;
}

/* ---------- 3. BUTTONS ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font: inherit; font-weight: 700; font-size: 1rem; cursor: pointer;
  padding: 14px 24px; border-radius: var(--r-btn); border: 2px solid transparent;
  transition: transform .2s var(--ease), box-shadow .2s var(--ease), background .2s var(--ease);
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn--primary { background: linear-gradient(135deg, #FF9A3D 0%, var(--c-accent) 52%, var(--c-accent-dark) 100%); color: #fff; box-shadow: 0 10px 24px rgba(247,130,27,.34); }
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 16px 34px rgba(247,130,27,.46); filter: saturate(1.06) brightness(1.02); }
.btn--ghost { background: #fff; color: var(--c-primary); border-color: var(--c-primary); }
.btn--ghost:hover { background: var(--c-primary-50); transform: translateY(-2px); }
.btn--on-dark { background: #fff; color: var(--c-primary-dark); }
.btn--on-dark:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.btn--block { width: 100%; }
.btn--lg { padding: 16px 30px; font-size: 1.05rem; }
.link-cta { color: var(--c-primary); font-weight: 700; display: inline-flex; align-items: center; gap: 6px; }
.link-cta:hover { gap: 10px; }

/* ---------- 4. HEADER ---------- */
.header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 50; background: transparent;
  border-bottom: 1px solid transparent;
  transition: background .25s, border-color .25s, box-shadow .25s;
}
.header.is-scrolled {
  background: rgba(255,255,255,.86); backdrop-filter: saturate(180%) blur(10px);
  border-color: var(--c-line); box-shadow: var(--shadow-sm);
}
.header__inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.logo { display: inline-flex; align-items: center; gap: 10px; }
.logo__mark { width: 34px; height: 34px; flex: none; }
.logo__wm { display: flex; flex-direction: column; line-height: 1; gap: 3px; }
.logo__navi { font-weight: 900; font-size: 1.3rem; letter-spacing: -.01em; background: linear-gradient(135deg, #FFB020, #F5481E); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; color: transparent; }
.logo__tag { font-size: .44rem; font-weight: 800; letter-spacing: .22em; color: #fff; -webkit-text-fill-color: #fff; background: linear-gradient(135deg, #FFB020, #F5481E); padding: 2px 0; border-radius: 3px; text-align: center; }
.nav { display: none; gap: 28px; }
.nav a { font-weight: 600; color: var(--c-ink-soft); font-size: .95rem; }
.nav a:hover { color: var(--c-primary); }
.header__cta { display: none; }
.burger { background: none; border: 0; cursor: pointer; padding: 8px; display: inline-flex; }
.burger span { width: 22px; height: 2px; background: var(--c-ink); display: block; position: relative; }
.burger span::before, .burger span::after { content: ""; position: absolute; left: 0; width: 22px; height: 2px; background: var(--c-ink); }
.burger span::before { top: -7px; } .burger span::after { top: 7px; }

/* Header NẰM TRÊN hero tối → chữ sáng; khi cuộn qua hero → nền trắng, chữ tối */
.header .logo { color: #fff; }
.header .nav a { color: rgba(255,255,255,.85); }
.header .nav a:hover { color: #fff; }
.header .burger span, .header .burger span::before, .header .burger span::after { background: #fff; }
.header.is-scrolled .logo { color: var(--c-primary-dark); }
.header.is-scrolled .nav a { color: var(--c-ink-soft); }
.header.is-scrolled .nav a:hover { color: var(--c-primary); }
.header.is-scrolled .burger span,
.header.is-scrolled .burger span::before,
.header.is-scrolled .burger span::after { background: var(--c-ink); }

/* ---------- 5. HERO ---------- */
.hero {
  position: relative; overflow: hidden; padding: 124px 0 88px; color: #fff;
  background:
    radial-gradient(1100px 560px at 82% -8%, rgba(247,130,27,.42), transparent 58%),
    radial-gradient(820px 520px at 6% 16%, rgba(124,77,255,.34), transparent 55%),
    linear-gradient(135deg, #1E54D6 0%, #143C9E 48%, #2B2F92 100%);
}
/* Vòng halo đồng tâm mờ phía sau (giống Scribe) */
.hero::before {
  content: ""; position: absolute; inset: 0; z-index: 0; pointer-events: none;
  background: repeating-radial-gradient(circle at 72% 42%, rgba(255,255,255,.07) 0 1px, transparent 1px 88px);
  -webkit-mask-image: radial-gradient(circle at 72% 42%, #000 0%, transparent 72%);
  mask-image: radial-gradient(circle at 72% 42%, #000 0%, transparent 72%);
}
.hero .wrap { position: relative; z-index: 1; }
.hero__grid { display: grid; gap: 56px; align-items: center; }
.hero__title { margin-bottom: 22px; color: #fff; }
.hero__title .hl { color: #FFC07A; }
.hero__sub { font-size: 1.22rem; max-width: 540px; line-height: 1.7; color: rgba(255,255,255,.9); }
.hero__cta { display: flex; flex-wrap: wrap; gap: 14px; margin: 32px 0 26px; }
.trust-bar { display: flex; flex-wrap: wrap; gap: 10px 18px; }
.trust-bar li { display: flex; align-items: center; gap: 7px; font-size: .92rem; font-weight: 600; color: var(--c-ink); }
.trust-bar .tick { color: var(--c-ok); font-weight: 900; }

/* Hero trên nền tối → eyebrow kính, nút phụ kính, trust-bar trắng */
.hero .eyebrow {
  background: rgba(255,255,255,.14); color: #fff;
  border: 1px solid rgba(255,255,255,.26); -webkit-backdrop-filter: blur(4px); backdrop-filter: blur(4px);
}
.hero .btn--ghost {
  background: rgba(255,255,255,.1); color: #fff; border-color: rgba(255,255,255,.55);
  -webkit-backdrop-filter: blur(4px); backdrop-filter: blur(4px);
}
.hero .btn--ghost:hover { background: rgba(255,255,255,.2); }
.hero .trust-bar li { color: #fff; }
.hero .trust-bar .tick { color: #7CF0B8; }

/* Lớp grain mịn tạo độ sâu */
.hero::after {
  content: ""; position: absolute; inset: 0; z-index: 0; pointer-events: none; opacity: .35; mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}
/* Quầng sáng sau cụm thẻ mockup */
.mockup::before {
  content: ""; position: absolute; left: 8%; top: 10%; width: 84%; height: 78%; z-index: -1;
  background: radial-gradient(circle at 60% 45%, rgba(132,165,255,.55), transparent 62%);
  filter: blur(46px);
}
/* Thẻ mockup trôi nhẹ lệch pha */
@keyframes floaty { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-9px); } }
.mock-live { animation: floaty 6s ease-in-out infinite; }
.mock-progress { animation: floaty 6.4s ease-in-out infinite .8s; }
.mock-route { animation: floaty 6.8s ease-in-out infinite 1.6s; }

/* Hero mockup — layered cards (SVG/CSS, thay ảnh thật sau) */
.mockup { position: relative; min-height: 360px; }
.mock-card { position: absolute; background: #fff; border: 1px solid var(--c-line); border-radius: var(--r-card); box-shadow: var(--shadow-lg); padding: 16px; }
.mock-live { left: 0; top: 10px; width: 76%; }
.mock-live__bar { display: flex; gap: 6px; margin-bottom: 10px; }
.mock-live__bar i { width: 10px; height: 10px; border-radius: 50%; background: var(--c-line); }
.mock-live__screen { aspect-ratio: 16/10; border-radius: 10px; background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-dark) 100%); display: grid; place-items: center; color: #fff; font-weight: 700; }
.mock-live__tiles { display: grid; grid-template-columns: repeat(3,1fr); gap: 6px; width: 80%; margin-top: 10px; }
.mock-live__tiles span { aspect-ratio: 1; border-radius: 6px; background: rgba(255,255,255,.25); }
.mock-live__screen.has-img { padding: 0; background: none; }
.mock-live__screen img { width: 100%; height: 100%; object-fit: cover; border-radius: 10px; }
.mock-progress { right: 0; top: 0; width: 46%; }
.mock-progress h4 { margin: 0 0 8px; font-size: .85rem; }
.bar { height: 8px; border-radius: 6px; background: var(--c-bg-alt); margin: 7px 0; overflow: hidden; }
.bar > i { display: block; height: 100%; border-radius: 6px; background: var(--c-accent); }
.mock-route { left: 5%; right: 5%; bottom: 0; width: auto; display: flex; align-items: center; justify-content: space-between; gap: 4px; }
.mock-route .step { flex: 1 1 0; min-width: 0; text-align: center; font-size: .66rem; font-weight: 700; color: var(--c-primary-dark); }
.mock-route .step b { display: grid; place-items: center; width: 28px; height: 28px; margin: 0 auto 4px; border-radius: 50%; background: var(--c-primary-50); color: var(--c-primary); font-size: .72rem; }
.mock-route .arrow { color: var(--c-no); font-weight: 900; font-size: .7rem; flex: none; }

/* ---------- 6. STATS STRIP ---------- */
.proof {
  display: grid; grid-template-columns: 1fr 1fr; gap: 4px;
  background: #fff; border: 1px solid var(--c-line); border-radius: 22px;
  box-shadow: var(--shadow); padding: 10px; position: relative; z-index: 2;
}
.proof__item { display: flex; align-items: center; gap: 13px; padding: 16px 14px; border-radius: 15px; position: relative; transition: background .2s var(--ease); }
.proof__item:hover { background: var(--c-bg-alt); }
.proof__ic { flex: none; width: 44px; height: 44px; border-radius: 13px; display: grid; place-items: center; color: var(--c-primary); background: linear-gradient(145deg, var(--c-primary-50), #fff); box-shadow: inset 0 0 0 1px rgba(27,95,203,.1); }
.proof__ic svg { width: 22px; height: 22px; }
.proof__value { font-size: 1.4rem; font-weight: 900; color: var(--c-primary); line-height: 1.1; }
.proof__label { font-size: .96rem; font-weight: 700; color: var(--c-ink); line-height: 1.35; }
.proof__label--solo { font-size: 1rem; }

/* ---------- 7. CARD GRIDS (problem / solution / features) ---------- */
.grid { display: grid; gap: var(--gap); }
.grid--3 { grid-template-columns: 1fr; }
.grid--4 { grid-template-columns: 1fr; }
.card {
  background: #fff; border: 1px solid var(--c-line); border-radius: var(--r-card);
  padding: 32px 30px; box-shadow: var(--shadow-sm);
  transition: transform .25s var(--ease), box-shadow .25s var(--ease);
}
.card:hover { transform: translateY(-5px); box-shadow: var(--shadow); }
.card__icon { width: 56px; height: 56px; border-radius: 16px; display: grid; place-items: center; margin-bottom: 18px; color: var(--c-primary); background: linear-gradient(145deg, var(--c-primary-50), #fff); box-shadow: inset 0 0 0 1px rgba(27,95,203,.08); transition: transform .25s var(--ease); }
.card__icon svg { width: 27px; height: 27px; }
.card:hover .card__icon { transform: scale(1.06) rotate(-2deg); }
.card--pain .card__icon { color: var(--c-accent-dark); background: linear-gradient(145deg, #FFF1E8, #fff); box-shadow: inset 0 0 0 1px rgba(247,130,27,.1); }
.card h3 { margin-bottom: 8px; }
.card p { margin: 0; font-size: 1rem; line-height: 1.65; }

/* ---------- 8. PROCESS TIMELINE (section WOW) ---------- */
.timeline { position: relative; display: grid; gap: 28px; }
.tl-line { display: none; }
.tl-step { display: flex; gap: 16px; align-items: flex-start; position: relative; }
.tl-step__num {
  flex: none; width: 52px; height: 52px; border-radius: 50%; display: grid; place-items: center;
  font-weight: 900; font-size: 1.1rem; color: #fff;
  background: linear-gradient(145deg, #3B7BE8, var(--c-primary-dark));
  box-shadow: 0 10px 22px rgba(27,95,203,.4), inset 0 1px 0 rgba(255,255,255,.25); z-index: 2;
}
.tl-step__body h3 { margin-bottom: 4px; }
.tl-step__body p { margin: 0; font-size: .95rem; }

/* ---------- 9. COURSE CARDS ---------- */
.course { display: flex; flex-direction: column; border-top: 4px solid var(--c-primary); }
.course__badge { align-self: flex-start; font-size: .78rem; font-weight: 800; letter-spacing: .04em; text-transform: uppercase; padding: 5px 12px; border-radius: var(--r-pill); margin-bottom: 12px; }
.course__lvl { font-size: 1.5rem; font-weight: 900; color: var(--c-ink); }
.course dl { margin: 14px 0 18px; display: grid; gap: 10px; }
.course dt { font-size: .72rem; font-weight: 800; letter-spacing: .05em; text-transform: uppercase; color: var(--c-primary); }
.course dd { margin: 2px 0 0; font-size: .95rem; color: var(--c-ink-soft); }
.course .btn { margin-top: auto; }
.course--a1 { border-color: #1FA971; } .course--a1 .course__badge { background: #E7F7F0; color: #16855a; }
.course--a2 { border-color: #1B5FCB; } .course--a2 .course__badge { background: var(--c-primary-50); color: var(--c-primary-dark); }
.course--b1 { border-color: #F7821B; } .course--b1 .course__badge { background: #FFF1E8; color: var(--c-accent-dark); }
.course--b2 { border-color: #7C4DFF; } .course--b2 .course__badge { background: #F0EBFF; color: #5b34d6; }
.course--a1:hover { box-shadow: 0 20px 44px rgba(31,169,113,.22); }
.course--a2:hover { box-shadow: 0 20px 44px rgba(27,95,203,.22); }
.course--b1:hover { box-shadow: 0 20px 44px rgba(247,130,27,.22); }
.course--b2:hover { box-shadow: 0 20px 44px rgba(124,77,255,.22); }
.course__lvl { background: linear-gradient(135deg, var(--c-ink), #3a4a63); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }

/* ---------- 10. COMPARE TABLE ---------- */
.compare { overflow: hidden; border: 1px solid var(--c-line); border-radius: var(--r-card); box-shadow: var(--shadow-sm); background: #fff; }
.compare table { width: 100%; border-collapse: collapse; }
.compare th, .compare td { padding: 16px 14px; text-align: left; border-bottom: 1px solid var(--c-line); font-size: .95rem; }
.compare thead th { font-weight: 800; background: var(--c-bg-alt); }
.compare th.col-navi, .compare td.col-navi { background: var(--c-primary-50); text-align: center; }
.compare thead th.col-navi { color: var(--c-primary-dark); background: linear-gradient(180deg, #fff, var(--c-primary-50)); border-top: 3px solid var(--c-primary); }
.compare td.col-other { text-align: center; color: var(--c-ink-soft); }
.rec { display: inline-block; margin-left: 6px; font-size: .6rem; font-weight: 800; letter-spacing: .04em; text-transform: uppercase; color: #fff; background: var(--c-accent); padding: 3px 9px; border-radius: var(--r-pill); vertical-align: middle; box-shadow: 0 4px 10px rgba(247,130,27,.35); }
.compare tr:last-child td { border-bottom: 0; }
.mark-ok { color: var(--c-ok); font-weight: 900; font-size: 1.1rem; }
.mark-no { color: var(--c-no); font-weight: 900; font-size: 1.1rem; }

/* ---------- 11. LEAD MAGNET (test trình độ) ---------- */
.lead { background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-dark) 100%); color: #fff; border-radius: 28px; padding: 56px 40px; box-shadow: var(--shadow-lg); }
.lead h2 { color: #fff; }
.lead p { color: rgba(255,255,255,.86); font-size: 1.1rem; }
.lead__grid { display: grid; gap: 40px; align-items: center; }
.form { background: #fff; border-radius: var(--r-card); padding: 28px; }
.form .field { margin-bottom: 14px; }
.form label { display: block; font-size: .85rem; font-weight: 700; color: var(--c-ink); margin-bottom: 6px; }
.form input, .form select { width: 100%; font: inherit; padding: 12px 14px; border: 1.5px solid var(--c-line); border-radius: 10px; color: var(--c-ink); background: #fff; }
.form input:focus, .form select:focus { outline: none; border-color: var(--c-primary); box-shadow: 0 0 0 3px var(--c-primary-50); }
.form__note { font-size: .8rem; color: var(--c-ink-soft); margin: 10px 0 0; text-align: center; }
.form__ok { display: none; margin-top: 12px; padding: 12px; border-radius: 10px; background: #E7F7F0; color: #16855a; font-weight: 600; font-size: .9rem; }

/* ---------- 12. TESTIMONIALS ---------- */
.testi-track { display: grid; gap: 20px; grid-template-columns: 1fr; }
.testi { background: #fff; border: 1px solid var(--c-line); border-radius: var(--r-card); padding: 24px; box-shadow: var(--shadow-sm); }
.testi__quote { font-size: 1rem; color: var(--c-ink); margin-bottom: 16px; }
.testi__who { display: flex; align-items: center; gap: 12px; }
.testi__avatar { width: 44px; height: 44px; border-radius: 50%; background: var(--c-primary-50); display: grid; place-items: center; font-weight: 800; color: var(--c-primary); }
.testi__name { font-weight: 700; font-size: .95rem; }
.testi__level { font-size: .82rem; color: var(--c-ink-soft); }
.placeholder-note { text-align: center; font-size: .85rem; color: var(--c-ink-soft); margin-top: 18px; }

/* ---------- Giáo viên ---------- */
.teacher { display: grid; gap: 36px; align-items: center; }
.teacher__media { position: relative; justify-self: center; width: 100%; max-width: 250px; }
.teacher__frame { border-radius: 24px; overflow: hidden; aspect-ratio: 4/5; box-shadow: var(--shadow-lg); background: linear-gradient(150deg, var(--c-primary), var(--c-primary-dark)); }
.teacher__frame img { width: 100%; height: 100%; object-fit: cover; object-position: top center; }
.teacher__badge { position: absolute; left: 14px; bottom: 14px; display: inline-flex; align-items: center; gap: 8px; background: #fff; border-radius: var(--r-pill); padding: 9px 16px; font-weight: 700; font-size: .9rem; color: var(--c-ink); box-shadow: var(--shadow); }
.teacher__badge span { font-size: 1.1rem; line-height: 1; }
.teacher__body h2 { margin-bottom: .2em; }
.teacher__facts { display: grid; gap: 14px; margin: 22px 0; }
.teacher__facts li { display: flex; gap: 13px; align-items: flex-start; font-weight: 600; color: var(--c-ink); font-size: 1rem; line-height: 1.5; }
.t-ic { flex: none; width: 40px; height: 40px; border-radius: 12px; display: grid; place-items: center; color: var(--c-primary); background: linear-gradient(145deg, var(--c-primary-50), #fff); box-shadow: inset 0 0 0 1px rgba(27,95,203,.1); }
.t-ic svg { width: 21px; height: 21px; }
.teacher__quote { border-left: 4px solid var(--c-accent); margin: 0 0 24px; padding: 4px 0 4px 16px; font-style: italic; color: var(--c-ink-soft); font-size: 1.05rem; }
.team { margin-top: 52px; }
.team__lead { max-width: 780px; margin: 0 auto 32px; text-align: center; font-size: 1.08rem; color: var(--c-ink-soft); }

/* ---------- Gallery ảnh thực tế ---------- */
.gallery { display: grid; grid-template-columns: repeat(2,1fr); gap: 14px; }
.gallery__item { margin: 0; border-radius: 16px; overflow: hidden; aspect-ratio: 4/3; box-shadow: var(--shadow-sm); }
.gallery__item img { width: 100%; height: 100%; object-fit: cover; transition: transform .45s var(--ease); }
.gallery__item:hover img { transform: scale(1.06); }

/* ---------- Kết quả học viên (auto-loop marquee vô hạn) ---------- */
.cert-marquee {
  position: relative; overflow: hidden; padding: 4px 0 8px;
  -webkit-mask-image: linear-gradient(90deg, transparent 0, #000 7%, #000 93%, transparent 100%);
  mask-image: linear-gradient(90deg, transparent 0, #000 7%, #000 93%, transparent 100%);
}
.certs { display: flex; width: max-content; animation: cert-scroll 80s linear infinite; will-change: transform; }
.cert-marquee:hover .certs,
.cert-marquee.is-paused .certs { animation-play-state: paused; }
@keyframes cert-scroll { from { transform: translateX(0); } to { transform: translateX(-50%); } }
.cert { position: relative; flex: 0 0 auto; width: 232px; margin-right: 16px; border-radius: 16px; overflow: hidden; background: #fff; border: 1px solid var(--c-line); box-shadow: var(--shadow); }
.cert img { width: 100%; height: auto; display: block; aspect-ratio: 720 / 1119; object-fit: cover; background: var(--c-bg-alt); }
.cert__badge { position: absolute; top: 10px; left: 10px; z-index: 2; background: linear-gradient(135deg, #FF9A3D, var(--c-accent)); color: #fff; font-weight: 800; font-size: .72rem; letter-spacing: .03em; padding: 5px 11px; border-radius: var(--r-pill); box-shadow: 0 4px 12px rgba(247,130,27,.45); }
.certs__note { max-width: 720px; margin: 18px auto 0; text-align: center; font-size: .9rem; color: var(--c-ink-soft); }
@media (min-width: 640px) { .cert { width: 256px; } }
@media (prefers-reduced-motion: reduce) {
  .certs { animation: none; }
  .cert-marquee { overflow-x: auto; -webkit-mask-image: none; mask-image: none; }
}

/* ---------- 13. FAQ ACCORDION ---------- */
.faq { max-width: var(--wrap-narrow); margin: 0 auto; }
.acc { border: 1px solid var(--c-line); border-radius: 16px; background: #fff; margin-bottom: 14px; overflow: hidden; box-shadow: var(--shadow-sm); }
.acc__q { width: 100%; text-align: left; font: inherit; font-weight: 700; font-size: 1.05rem; color: var(--c-ink); background: none; border: 0; cursor: pointer; padding: 22px 24px; display: flex; justify-content: space-between; align-items: center; gap: 16px; }
.acc__q .chev { transition: transform .25s var(--ease); color: var(--c-primary); font-weight: 900; }
.acc.is-open .acc__q .chev { transform: rotate(45deg); }
.acc__a { max-height: 0; overflow: hidden; transition: max-height .3s var(--ease); }
.acc__a p { padding: 0 20px 18px; margin: 0; font-size: .95rem; }

/* ---------- 14. FINAL CTA ---------- */
.final-cta { text-align: center; background: var(--c-primary-50); border-radius: 28px; padding: 64px 28px; }
.final-cta h2 { margin-bottom: 26px; }
.final-cta .hero__cta { justify-content: center; }

/* ---------- 15. FOOTER ---------- */
.footer { background: var(--c-ink); color: #C9D4E3; padding: 48px 0 28px; }
.footer__grid { display: grid; gap: 28px; grid-template-columns: 1fr; }
.footer .logo { color: #fff; margin-bottom: 12px; }
.footer p { color: #9FB0C6; font-size: .92rem; }
.footer h4 { color: #fff; font-size: .95rem; margin: 0 0 12px; }
.footer a { color: #C9D4E3; font-size: .92rem; display: inline-block; padding: 3px 0; }
.footer a:hover { color: #fff; }
.footer__bottom { border-top: 1px solid rgba(255,255,255,.1); margin-top: 32px; padding-top: 18px; font-size: .82rem; color: #8194ac; text-align: center; }

/* ---------- 16. STICKY: Zalo float + mobile CTA bar ---------- */
.zalo-float {
  position: fixed; right: 16px; bottom: 84px; z-index: 60; width: 56px; height: 56px;
  border-radius: 50%; background: #0068FF; color: #fff; display: grid; place-items: center;
  box-shadow: 0 8px 22px rgba(0,104,255,.45); font-weight: 800; font-size: .7rem; line-height: 1;
  animation: pulse 2.4s infinite;
}
.zalo-float small { font-size: .62rem; }
@keyframes pulse { 0%,100% { box-shadow: 0 8px 22px rgba(0,104,255,.45);} 50% { box-shadow: 0 8px 30px rgba(0,104,255,.7);} }

.mobile-cta {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 60;
  display: grid; grid-template-columns: 1fr 1fr; gap: 10px; padding: 10px 14px;
  background: rgba(255,255,255,.96); backdrop-filter: blur(8px); border-top: 1px solid var(--c-line);
  transform: translateY(120%); transition: transform .3s var(--ease);
}
.mobile-cta.is-visible { transform: translateY(0); }
.mobile-cta .btn { padding: 12px; font-size: .92rem; }

/* ---------- 17. MOTION (scroll reveal) ---------- */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .6s var(--ease), transform .6s var(--ease); }
.reveal.is-in { opacity: 1; transform: none; }
.reveal[data-delay="1"] { transition-delay: .08s; }
.reveal[data-delay="2"] { transition-delay: .16s; }
.reveal[data-delay="3"] { transition-delay: .24s; }
.reveal[data-delay="4"] { transition-delay: .32s; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
  .zalo-float { animation: none; }
  .mock-live, .mock-progress, .mock-route { animation: none; }
}

/* ============================================================
   18. RESPONSIVE (mobile-first → up)
   ============================================================ */
@media (min-width: 640px) {
  .proof { grid-template-columns: repeat(4,1fr); }
  .proof__item + .proof__item::before { content: ""; position: absolute; left: 0; top: 18%; bottom: 18%; width: 1px; background: var(--c-line); }
  .gallery { grid-template-columns: repeat(3,1fr); }
  .grid--3 { grid-template-columns: repeat(2,1fr); }
  .grid--4 { grid-template-columns: repeat(2,1fr); }
  .testi-track { grid-template-columns: repeat(2,1fr); }
}
@media (min-width: 880px) {
  :root { --section-y: 120px; --gap: 32px; }
  body { padding-bottom: 0; }
  .proof { margin-top: -76px; }
  .mock-route { left: auto; right: 8px; width: 60%; gap: 6px; }
  .mock-route .step { font-size: .72rem; }
  .mock-route .step b { width: 30px; height: 30px; font-size: .78rem; }
  .nav { display: flex; }
  .header__cta { display: inline-flex; }
  .burger { display: none; }
  .hero__grid { grid-template-columns: 1.05fr .95fr; }
  .grid--3 { grid-template-columns: repeat(3,1fr); }
  .grid--4 { grid-template-columns: repeat(4,1fr); }
  .testi-track { grid-template-columns: repeat(3,1fr); }
  .lead__grid { grid-template-columns: 1.1fr .9fr; }
  .teacher { grid-template-columns: .82fr 1.18fr; gap: 56px; }
  .teacher__media { justify-self: start; max-width: 360px; }
  .gallery { grid-template-columns: repeat(4,1fr); }
  .footer__grid { grid-template-columns: 1.6fr 1fr 1fr; }
  .mobile-cta { display: none !important; }
  .zalo-float { bottom: 24px; }

  /* Timeline ngang trên desktop */
  .timeline { grid-template-columns: repeat(5,1fr); gap: 16px; }
  .tl-step { flex-direction: column; text-align: center; align-items: center; }
  .tl-step__body h3 { font-size: 1rem; }
  .tl-line { display: block; position: absolute; top: 26px; left: 10%; right: 10%; height: 3px; background: var(--c-line); z-index: 0; }
  .tl-line > i { display: block; height: 100%; width: 0; background: linear-gradient(90deg, var(--c-primary-dark), #6AA0FF); transition: width 1.2s var(--ease); }
  .timeline.is-in .tl-line > i { width: 100%; }
}
@media (min-width: 1024px) {
  .hero { padding: 156px 0 116px; }
  .hero__grid { gap: 72px; }
}