html{ font-family: "Inter", system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif; }

:root{
  --brand:#004aad;
  --text:#0d1b2a;
  --header-h:86px;
}

/* HEADER KHUNG CHUNG */
header.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: #fff;
  border-bottom: 1px solid #eef1f5;
}
body {
  padding-top: 86px; /* bằng chiều cao header */
}

header.site-header .container{
  max-width:1200px; margin:0 auto; padding:14px 16px;
  height:var(--header-h); display:flex; align-items:center; gap:24px;
}
header.site-header .brand img{ display:block; height:48px; width:auto; }

/* NAV + LINK */
header.site-header .main-nav{ margin-left:auto; }
header.site-header .menu{ list-style:none; margin:0; padding:0; display:flex; gap:28px; align-items:center; }
header.site-header .menu > li{ position:relative; }
header.site-header .menu a,
header.site-header .toggle-sub{
  font-size:18px; font-weight:600; color:var(--text);
  text-decoration:none; background:none; border:0; padding:8px 4px; cursor:pointer;
  display:inline-flex; align-items:center; gap:6px;
}
header.site-header .menu a:hover,
header.site-header .toggle-sub:hover{ color:var(--brand); }
header.site-header .caret{ transform:translateY(1px); opacity:.8; }

/* DROPDOWN */
header.site-header .sub{
  position:absolute; left:0; top:calc(100% + 10px);
  min-width:240px; background:#fff; border:1px solid #eef1f5; border-radius:12px;
  box-shadow:0 12px 28px rgba(16,24,40,.12);
  padding:8px; display:block;
}
header.site-header .sub[hidden]{ display:none; }
header.site-header .sub li{ list-style:none; }
header.site-header .sub a{
  display:block; padding:10px 12px; font-size:16px; font-weight:500; border-radius:8px;
}
header.site-header .sub a:hover{ background:#f4f6fa; color:var(--brand); }

/* MOBILE MENU */
header.site-header .nav-toggle{ display:none; margin-left:12px; width:40px;height:40px;border:0;background:transparent; }
header.site-header .nav-toggle span{ display:block; height:2px; margin:7px 0; background:#172026; }

@media (max-width: 900px){
  header.site-header .menu{ 
    position:absolute; right:16px; left:16px; top:calc(var(--header-h) - 4px);
    flex-direction:column; align-items:stretch;
    background:#fff; border:1px solid #eef1f5; border-radius:12px;
    padding:12px; display:none;
  }
  header.site-header .main-nav.open .menu{ display:flex; }
  header.site-header .nav-toggle{ display:block; }

  header.site-header .sub{
    position:static; min-width:unset; box-shadow:none; border:0; padding:4px 0 0 8px;
  }
  header.site-header .sub a{ padding:8px 10px; }
}

/* Tránh header che anchor khi cuộn */
html{ scroll-padding-top: var(--header-h); }

/* Giữ typography đồng nhất cho header trên mọi trang */
header.site-header .menu a,
header.site-header .toggle-sub{
  font-family: inherit;          /* dùng cùng font với toàn site */
  font-size: 18px;               /* giống trang chủ */
  font-weight: 700;              /* dày như trang chủ (trước là 600) */
  line-height: 1.6;
  letter-spacing: 0;
  text-transform: none;
  -webkit-appearance: none;
  appearance: none;
}

/* Nếu trang nào có rule a { font-weight:... } thì rule dưới sẽ thắng */
header.site-header a{ font-weight: 700 !important; }