:root {
  /* Brand colors */
  --brand-primary: #07131f;
  --brand-secondary: #0c1b2a;
  --brand-accent: #d4a25a;
  --brand-accent-2: #c9983a;
  --brand-text: #172233;
  --brand-muted: #68717d;
  --brand-line: #e8e4dd;
  --brand-bg: #ffffff;

  /* Legacy aliases — keep existing CSS working */
  --navy: #07131f;
  --navy2: #0c1b2a;
  --gold: #d4a25a;
  --gold2: #c9983a;
  --text: #172233;
  --muted: #68717d;
  --line: #e8e4dd;
  --bg: #ffffff;

  /* Typography */
  --font-body: 'Montserrat', Arial, sans-serif;
  --font-heading: 'Montserrat', Arial, sans-serif;
  --font-size-base: 16px;
  --font-size-h1: 40px;
  --font-size-h2: 30px;
  --font-size-h3: 20px;
  --font-size-body: 16px;
  --font-size-small: 12px;
  --font-size-nav: 14px;
  --font-size-btn: 14px;

  /* Layout */
  --container-width: 1400px;
  --section-spacing: 80px;
  --grid-gap: 24px;

  /* Button */
  --btn-radius: 2px;
  --btn-padding: 14px 24px;

  /* Card */
  --card-radius: 4px;
  --card-shadow: 0 10px 30px rgba(0,0,0,0.08);
  --image-radius: 4px;
}

body {
  font-family: var(--font-body);
  background-color: var(--brand-bg);
  color: var(--brand-text);
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
}

/* Typography size — these selectors load after page CSS so same-specificity rules win */
body { font-size: var(--font-size-body); }
.nav { font-size: var(--font-size-nav); }
.btn { font-size: var(--font-size-btn); padding: var(--btn-padding); }
h1 { font-size: var(--font-size-h1); }
h2 { font-size: var(--font-size-h2); }
h3 { font-size: var(--font-size-h3); }

/* Description (mô tả) — paragraph text under section/page headings */
.section-title p, .section-title span, .page-head p,
.hero-desc, .about-content p, .intro-copy p { font-size: var(--font-size-body); }

/* Small labels & captions (ghi chú) — eyebrow text, breadcrumbs, section labels */
.section-label, .eyebrow, .breadcrumb { font-size: var(--font-size-base); }

/* Small text tier — card descriptions, overlays, timestamps, tags, footer, copyright */
.stat span, .tabs button, .filters button, .img-overlay,
.project-grid p, .step h3, .blog-grid time, .blog-grid p, .blog-grid a,
.member p, .idea-step h3, .idea-step p, .news-card time, .news-card a,
.related-card span, .category-list span, .team-grid h3 { font-size: var(--font-size-small); }

/* ═══════════════════════════════════════════════════════════
   Header Layout Styles
   data-hd: desktop style   data-ht: tablet (≤960px)   data-hm: mobile (≤559px)
═══════════════════════════════════════════════════════════ */

/* ── Desktop Style 2: Sáng (Light) ─────────────────────── */
.site-header[data-hd="2"] {
  background: var(--brand-bg, #fff);
  border-bottom: 1px solid var(--brand-line, #e8e4dd);
  box-shadow: 0 2px 10px rgba(0,0,0,.06);
}
.site-header[data-hd="2"] .brand-text strong { color: var(--brand-primary, #07131f); }
.site-header[data-hd="2"] .brand-text small { color: var(--brand-muted, #68717d); }
.site-header[data-hd="2"] .brand-mark { color: var(--brand-accent, #d4a25a); }
.phone {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  color: #fff;
  font-weight: 700;
  white-space: nowrap;
  text-decoration: none;
}
.phone:hover { color: var(--brand-accent, #d4a25a); }
.brand-logo-img {
  display: block;
  width: auto;
  max-width: 150px;
  max-height: 42px;
  object-fit: contain;
  flex: none;
}
.brand-logo-img--main { display: none; }
.brand-logo-img--dark { display: block; }
.site-header[data-hd="2"] .brand-logo-img--main { display: block; }
.site-header[data-hd="2"] .brand-logo-img--dark { display: none; }
.footer .brand-logo-img,
.m4-drawer .brand-logo-img {
  max-width: 138px;
  max-height: 42px;
}
.site-header[data-hd="2"] .nav a { color: var(--brand-text, #172233); }
.site-header[data-hd="2"] .nav a.active,
.site-header[data-hd="2"] .nav a:hover { color: var(--brand-accent, #d4a25a); }
.site-header[data-hd="2"] .nav a:after { background: var(--brand-accent, #d4a25a); }
.site-header[data-hd="2"] .phone { color: var(--brand-primary, #07131f); }
.site-header[data-hd="2"] .phone:hover { color: var(--brand-accent, #d4a25a); }
.site-header[data-hd="2"] .menu-toggle { color: var(--brand-primary, #07131f); }

/* ── Desktop Style 3: Kính mờ (Glass) ──────────────────── */
.site-header[data-hd="3"] {
  background: rgba(7,19,31,.72);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(255,255,255,.09);
  box-shadow: none;
}
.site-header[data-hd="3"] .nav { gap: 38px; letter-spacing: .4px; }

/* ── Tablet Style 2: Nav ngang (Horizontal nav) ─────────── */
@media (max-width: 960px) {
  .site-header[data-ht="2"] .nav {
    display: flex !important;
    flex-direction: row;
    position: static;
    background: transparent;
    padding: 0;
    gap: 14px;
    font-size: 10px;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    flex: 1;
    justify-content: center;
    text-align: left;
  }
  .site-header[data-ht="2"] .nav.open { display: flex !important; }
  .site-header[data-ht="2"] .menu-toggle { display: none !important; }
}

/* ── Tablet Style 3: Logo giữa (Centered logo) ──────────── */
@media (max-width: 960px) {
  .site-header[data-ht="3"] .header-inner {
    justify-content: center;
    position: relative;
    gap: 0;
  }
  .site-header[data-ht="3"] .brand { margin: 0 auto; min-width: auto; }
  .site-header[data-ht="3"] .nav { display: none !important; }
  .site-header[data-ht="3"] .phone { display: none !important; }
  .site-header[data-ht="3"] .header-actions .btn { display: none; }
  .site-header[data-ht="3"] .menu-toggle { position: absolute; left: 16px; }
}

/* ════════════════════════════════════════════════════════════
   MOBILE MENU BAR — thiết kế lại (styles 1/2/3). Style 4 = drawer riêng.
   ════════════════════════════════════════════════════════════ */

/* Hamburger — nút icon bo góc, đổi sang ✕ khi mở (≤960px) */
@media (max-width: 960px) {
  .site-header .menu-toggle {
    display: grid; place-items: center;
    width: 40px; height: 40px; padding: 0;
    font-size: 0; line-height: 0; cursor: pointer;
    border: 1px solid rgba(255,255,255,.16);
    border-radius: 10px;
    background: rgba(255,255,255,.06);
    transition: background .2s, border-color .2s, transform .12s;
  }
  .site-header .menu-toggle::before { content: "\2630"; font-size: 19px; line-height: 1; color: #fff; }
  .site-header .menu-toggle:hover { background: rgba(255,255,255,.12); }
  .site-header .menu-toggle:active { transform: scale(.93); }
  /* Header sáng (data-hd=2) → nút tối */
  .site-header[data-hd="2"] .menu-toggle { border-color: rgba(7,19,31,.14); background: rgba(7,19,31,.05); }
  .site-header[data-hd="2"] .menu-toggle::before { color: var(--brand-primary, #07131f); }
}

/* Bar + dropdown cho style 1/2/3 (≤559px) */
/* Layout: hamburger (trái) | logo (phải) · số điện thoại ẩn */
@media (max-width: 559px) {
  .site-header:not([data-hm="4"]) .header-inner { gap: 10px; }
  .site-header:not([data-hm="4"]) .header-actions { order: 1; margin-left: 0; gap: 8px; }
  .site-header:not([data-hm="4"]) .brand { order: 3; margin-left: auto; min-width: 0; }
  .site-header:not([data-hm="4"]) .header-actions .btn-gold { display: none; }
  .site-header:not([data-hm="4"]) .header-actions .phone { display: none !important; }

  /* Dropdown trượt xuống full-width */
  .site-header:not([data-hm="4"]) .nav {
    position: fixed; top: 56px; left: 0; right: 0;
    flex-direction: column; align-items: stretch; justify-content: flex-start; gap: 0;
    padding: 6px 0 14px;
    background: var(--brand-primary, #07131f);
    border-top: 1px solid rgba(255,255,255,.08);
    box-shadow: 0 20px 44px rgba(0,0,0,.42);
    max-height: calc(100vh - 56px); overflow-y: auto;
  }
  .site-header:not([data-hm="4"]) .nav.open { display: flex; animation: khNavDrop .26s cubic-bezier(.4,0,.2,1); }
  @keyframes khNavDrop { from { opacity: 0; transform: translateY(-12px); } to { opacity: 1; transform: none; } }

  .site-header:not([data-hm="4"]) .nav a {
    flex: none; text-align: left; text-transform: none;
    font-size: 14px; font-weight: 600; letter-spacing: .2px;
    padding: 14px 22px; color: #eef1f4;
    border-bottom: 1px solid rgba(255,255,255,.06);
    display: flex; align-items: center; justify-content: space-between;
  }
  .site-header:not([data-hm="4"]) .nav a::after {
    content: "\203A"; position: static; display: inline; width: auto; height: auto;
    background: none; transform: none; opacity: .32; font-size: 17px; font-weight: 400;
  }
  .site-header:not([data-hm="4"]) .nav a.active,
  .site-header:not([data-hm="4"]) .nav a:hover { color: var(--gold, #d4a25a); background: rgba(255,255,255,.05); }
  .site-header:not([data-hm="4"]) .nav a.active::after,
  .site-header:not([data-hm="4"]) .nav a:hover::after { opacity: .85; }

  /* Hamburger → ✕ khi nav mở */
  .site-header:not([data-hm="4"]) .nav.open ~ .header-actions .menu-toggle::before { content: "\2715"; font-size: 17px; }

  /* Header sáng → dropdown nền trắng */
  .site-header[data-hd="2"]:not([data-hm="4"]) .nav { background: #fff; border-top-color: var(--brand-line, #e8e4dd); }
  .site-header[data-hd="2"]:not([data-hm="4"]) .nav a { color: var(--brand-text, #172233); border-bottom-color: rgba(0,0,0,.06); }

  /* ── Style 3: Thu gọn 48px ── */
  .site-header[data-hm="3"], .site-header[data-hm="3"] .header-inner { height: 48px; }
  .site-header[data-hm="3"] .brand-text { display: none; }
  .site-header[data-hm="3"] .brand-logo-img { max-height: 30px; }
  .site-header[data-hm="3"] .brand-mark, .site-header[data-hm="3"] .brand-mark svg { width: 36px; height: 28px; }
  .site-header[data-hm="3"] .menu-toggle { width: 34px; height: 34px; }
  .site-header[data-hm="3"] .menu-toggle::before { font-size: 17px; }
  .site-header[data-hm="3"] .nav { top: 48px; max-height: calc(100vh - 48px); }
}

/* ── Mobile Style 4: Slide Drawer ───────────────────────── */
/* Top bar: hamburger (trái) | logo (phải) · số điện thoại ẩn */
@media (max-width: 559px) {
  .site-header[data-hm="4"] .header-inner { position: relative; }
  .site-header[data-hm="4"] .brand { order: 3; margin-left: auto; }
  .site-header[data-hm="4"] .nav { display: none !important; }
  .site-header[data-hm="4"] .header-actions { order: 1; }
  .site-header[data-hm="4"] .header-actions .btn-gold { display: none; }
  .site-header[data-hm="4"] .header-actions .phone { display: none !important; }
}

/* Drawer shell — hidden by default (all breakpoints) */
.m4-drawer {
  position: fixed;
  top: 0; left: 0; bottom: 0;
  width: min(82vw, 300px);
  height: 100vh;
  background: var(--brand-primary, #07131f);
  z-index: 1100;
  display: flex;
  flex-direction: column;
  transform: translateX(-100%);
  transition: transform 0.32s cubic-bezier(.4,0,.2,1);
  pointer-events: none;
  visibility: hidden;
  box-shadow: 4px 0 32px rgba(0,0,0,.45);
}
.m4-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.52);
  z-index: 1099;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.32s ease;
  visibility: hidden;
}

/* Activate drawer only on mobile style 4 */
@media (max-width: 559px) {
  .site-header[data-hm="4"] ~ .m4-drawer,
  .site-header[data-hm="4"] ~ .m4-overlay { visibility: visible; }
  .site-header[data-hm="4"] ~ .m4-drawer.is-open {
    transform: translateX(0);
    pointer-events: auto;
  }
  .site-header[data-hm="4"] ~ .m4-overlay.is-open {
    opacity: 1;
    pointer-events: auto;
  }
}

/* Drawer — header area (logo + close button) */
.m4-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 20px 16px;
  border-bottom: 1px solid rgba(255,255,255,.1);
  flex-shrink: 0;
}
.m4-head .brand-mark { color: var(--brand-accent, #d4a25a); }
.m4-head .brand-text strong { color: #fff; font-size: 12px; letter-spacing: .5px; }
.m4-head .brand-text small { color: rgba(255,255,255,.45); font-size: 8px; }
.m4-close {
  background: rgba(255,255,255,.08);
  border: 0;
  border-radius: 50%;
  width: 32px; height: 32px;
  display: grid; place-items: center;
  cursor: pointer;
  color: rgba(255,255,255,.85);
  flex-shrink: 0;
  transition: background .2s;
}
.m4-close:hover { background: rgba(255,255,255,.16); }
.m4-close svg { width: 16px; height: 16px; }

/* Drawer — nav links (middle, scrollable) */
.m4-nav {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  padding: 10px 0;
}
.m4-nav a {
  display: flex;
  align-items: center;
  gap: 13px;
  padding: 13px 24px;
  color: rgba(255,255,255,.78);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .3px;
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: color .18s, background .18s, border-color .18s;
}
.m4-nav a svg { width: 17px; height: 17px; flex-shrink: 0; opacity: .7; transition: opacity .18s; }
.m4-nav a:hover,
.m4-nav a.active {
  color: var(--brand-accent, #d4a25a);
  background: rgba(255,255,255,.05);
  border-left-color: var(--brand-accent, #d4a25a);
}
.m4-nav a:hover svg,
.m4-nav a.active svg { opacity: 1; }

/* Drawer — footer (CTA + login) */
.m4-foot {
  padding: 16px 20px 22px;
  border-top: 1px solid rgba(255,255,255,.1);
  display: flex;
  flex-direction: column;
  gap: 10px;
  flex-shrink: 0;
}
.m4-foot .btn-gold { width: 100%; text-align: center; justify-content: center; display: block; }
.m4-login {
  display: block;
  text-align: center;
  color: rgba(255,255,255,.6);
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  padding: 9px;
  border: 1px solid rgba(255,255,255,.18);
  border-radius: var(--btn-radius, 2px);
  transition: color .18s, border-color .18s;
}
.m4-login:hover { color: #fff; border-color: rgba(255,255,255,.38); }

/* ─── Responsive: iPad (≤ 992px) ──────────────────────────────────────────── */
@media (max-width: 992px) {
  :root {
    --font-size-h1: 40px;
    --font-size-h2: 32px;
    --font-size-h3: 22px;
    --font-size-body: 15px;
    --font-size-small: 12px;
    --font-size-base: 15px;
    --font-size-nav: 13px;
    --font-size-btn: 13px;
    --section-spacing: 60px;
    --grid-gap: 20px;
    --container-padding: 24px;
  }
  h1 { font-size: var(--font-size-h1); }
  h2 { font-size: var(--font-size-h2); }
  h3 { font-size: var(--font-size-h3); }
  body { font-size: var(--font-size-body); }
  .nav { font-size: var(--font-size-nav); }
  .btn { font-size: var(--font-size-btn); }
  .section { padding: var(--section-spacing) 0; }
  .container { padding-left: var(--container-padding); padding-right: var(--container-padding); }
  .grid, .project-grid, .service-grid, .blog-grid { gap: var(--grid-gap); }
}

/* ─── Responsive: Mobile (≤ 767px) ────────────────────────────────────────── */
@media (max-width: 767px) {
  :root {
    --font-size-h1: 28px;
    --font-size-h2: 22px;
    --font-size-h3: 18px;
    --font-size-body: 14px;
    --font-size-small: 11px;
    --font-size-base: 14px;
    --font-size-nav: 12px;
    --font-size-btn: 12px;
    --section-spacing: 40px;
    --grid-gap: 12px;
    --container-padding: 16px;
  }
  h1 { font-size: var(--font-size-h1); }
  h2 { font-size: var(--font-size-h2); }
  h3 { font-size: var(--font-size-h3); }
  body { font-size: var(--font-size-body); }
  .nav { font-size: var(--font-size-nav); }
  .btn { font-size: var(--font-size-btn); }
  .section { padding: var(--section-spacing) 0; }
  .container { padding-left: var(--container-padding); padding-right: var(--container-padding); }
  .grid, .project-grid, .service-grid, .blog-grid { gap: var(--grid-gap); }
  .footer-col-2 { display: none; }
  .footer-col-3 { display: none; }
  .footer-col-4 { display: none; }
  .footer-col-5 { display: none; }
}