/* Natural English System - giao diện chung cho mọi trang (nạp SAU <style> riêng của trang để ghi đè).
   Bố cục theo kiểu trang giới thiệu: header trắng có logo + menu chữ in hoa, nút "3D" có viền đáy đậm,
   footer màu thương hiệu có thông tin liên hệ. Màu lấy từ logo (img/logo-full.png). */
:root{
  --navy:#1e3a66; --navy-d:#142a4c;
  --teal:#1fa9a6; --teal-d:#15807d;
  --orange:#ef7a2e; --orange-d:#c65f1c;
  --green:#7ab648; --blue:#1c7bbc; --yellow:#f2b632;
  --hair:#e5e8ee; --soft:#f3f6fa; --text:#33435a; --text-2:#6b778a;
  /* ghi đè biến cũ của các trang */
  --accent:#1e3a66; --accent2:#1c7bbc; --bg:#f7f9fb; --ink:#22324a; --muted:#6b778a; --line:#e5e8ee; --chip:#eef4fa;
  /* cùng giá trị các trang cũ tự khai báo; trang mới (đăng nhập, tài khoản, quản trị) dùng chung */
  --panel:#ffffff; --hover:#f0f5fb; --ok:#1a8a4a; --okbg:#e6f6ec; --bad:#c0392b; --badbg:#fbeceb; --warn:#b8860b;
}
@media (prefers-color-scheme: dark){
  :root{ --hair:#2b3442; --soft:#18202b; --text:#d9e1ec; --text-2:#9aa6b6;
    --accent:#14243d; --accent2:#7cc4ee; --bg:#10151c; --ink:#e6edf6; --muted:#9aa6b6; --line:#2b3442; --chip:#1d2733;
    --panel:#1a2029; --hover:#222c38; --ok:#48c980; --okbg:#12301f; --bad:#f2827a; --badbg:#3a1d1b; --warn:#e0b34d; }
}
body{font-family:'Nunito',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;background:var(--bg)}
[hidden]{display:none !important}  /* CSS display của từng khối không được thắng thuộc tính hidden */
.muted{color:var(--text-2)}
.gap{display:inline-block;width:14px}  /* khoảng cách giữa các mục thông tin, thay cho dấu chấm giữa */
.ptitle{color:var(--navy);font-size:24px;font-weight:900;margin:4px 0 14px}
@media (prefers-color-scheme: dark){ .ptitle{color:#e9f0f8} }
h1,h2,h3{font-family:'Nunito',-apple-system,'Segoe UI',Roboto,Arial,sans-serif;letter-spacing:-.01em}

/* ---------- header ---------- */
header.site{position:sticky;top:0;z-index:20;background:#fff;border-bottom:2px solid var(--hair);padding:0;color:var(--navy);box-shadow:none}
.site-in{max-width:1120px;margin:0 auto;padding:10px 20px;display:flex;align-items:center;gap:18px;min-height:64px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--navy);flex:none}
.brand img{width:44px;height:44px;object-fit:contain}
.brand .bt{display:flex;flex-direction:column;line-height:1}
.brand .bt b{font-size:17px;font-weight:900;letter-spacing:.01em;color:var(--navy)}
.brand .bt small{font-size:10.5px;font-weight:800;letter-spacing:.32em;color:var(--teal);margin-top:3px}
.mainnav{display:flex;gap:4px;margin-left:auto;flex-wrap:wrap}
.mainnav a{color:var(--text-2);text-decoration:none;font-size:13px;font-weight:800;text-transform:uppercase;letter-spacing:.06em;
  padding:9px 12px;border-radius:10px;background:none;white-space:nowrap}
.mainnav a:hover{color:var(--navy);background:var(--soft)}
.mainnav a.cur{color:var(--blue);background:#e9f3fb}
@media (prefers-color-scheme: dark){
  header.site{background:#151c26}
  .brand .bt b{color:#e6edf6}
  .mainnav a.cur{background:#1b2a3b;color:#8fd0f5}
  .brand img{background:#fff;border-radius:10px;padding:3px}
}
@media (max-width:720px){
  .site-in{flex-wrap:wrap;gap:8px;padding:8px 14px}
  .mainnav{margin-left:0;width:100%;flex-wrap:nowrap;overflow-x:auto;gap:2px}
  .mainnav a{padding:7px 10px;font-size:12px}
  .hide-sm{display:none !important}
}

/* ---------- nút 3D ---------- */
.btn3d{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:12px 24px;border-radius:14px;border:0;
  background:var(--teal);color:#fff !important;font:inherit;font-weight:900;font-size:14px;text-transform:uppercase;letter-spacing:.07em;
  text-decoration:none;cursor:pointer;box-shadow:0 4px 0 var(--teal-d);transition:transform .07s,box-shadow .07s,filter .15s;white-space:nowrap}
.btn3d:hover{filter:brightness(1.06)}
.btn3d:active{transform:translateY(4px);box-shadow:0 0 0 var(--teal-d)}
.btn3d.sm{padding:9px 16px;font-size:12.5px;border-radius:12px}
.btn3d.lg{padding:15px 34px;font-size:15px;min-width:260px}
.btn3d.orange{background:var(--orange);box-shadow:0 4px 0 var(--orange-d)}
.btn3d.ghost{background:#fff;color:var(--blue) !important;box-shadow:0 4px 0 var(--hair);outline:2px solid var(--hair);outline-offset:-2px}
.btn3d.ghost:active{box-shadow:0 0 0 var(--hair)}
@media (prefers-color-scheme: dark){ .btn3d.ghost{background:#1b2430;color:#8fd0f5 !important;outline-color:#2b3442;box-shadow:0 4px 0 #2b3442} }

/* nút sẵn có của các trang: bo tròn + viền đáy kiểu 3D cho đồng bộ */
button.btn{border-radius:12px;border:2px solid var(--hair);box-shadow:0 3px 0 var(--hair);font-family:inherit;font-weight:700}
button.btn:active:not(:disabled){transform:translateY(3px);box-shadow:none}
button.btn:disabled{opacity:.45;cursor:default}
button.btn.primary{background:var(--teal);border-color:var(--teal);color:#fff;box-shadow:0 3px 0 var(--teal-d)}
button.btn.on{background:var(--blue);border-color:var(--blue);color:#fff;box-shadow:0 3px 0 #135c8f}
.card{border-width:2px;border-color:var(--hair);border-radius:16px}

/* ---------- footer ---------- */
footer.site{margin-top:40px;background:var(--navy);color:#dbe5f2;font-size:14px}
footer.site a{color:#fff;text-decoration:none}
footer.site a:hover{text-decoration:underline}
footer.site .wave{display:block;width:100%;height:46px;background:var(--bg);color:var(--navy)}
@media (prefers-color-scheme: dark){ footer.site .wave{color:#0d1e37} }
footer.site .fin{max-width:1120px;margin:0 auto;padding:26px 20px 18px}
.tile{display:inline-grid;place-items:center;background:#fff;border-radius:14px;padding:6px;flex:none}
.tile img{width:52px;height:52px;object-fit:contain;display:block}
.f-row{display:flex;gap:22px;align-items:center;justify-content:space-between;flex-wrap:wrap}
.f-brand{display:flex;gap:12px;align-items:center}
.f-brand b{display:block;color:#fff;font-size:16px;font-weight:900}
.f-brand small{color:#a9bad1;font-size:13px}
.f-contact{display:flex;gap:8px 18px;flex-wrap:wrap;align-items:center}
.f-contact span{color:#a9bad1}
.f-contact b{color:#fff}
.f-note{border-top:1px solid rgba(255,255,255,.14);margin-top:18px;padding-top:12px;font-size:12.5px;color:#9fb1c9;display:flex;
  justify-content:space-between;gap:10px;flex-wrap:wrap}
.f-cols{display:grid;grid-template-columns:1.5fr 1fr 1.3fr 1.4fr;gap:26px}
.f-cols h4{margin:0 0 10px;color:#fff;font-size:15px;font-weight:900}
.f-cols ul{list-style:none;margin:0;padding:0}
.f-cols li{margin:6px 0;color:#c7d4e6}
@media (max-width:820px){ .f-cols{grid-template-columns:1fr 1fr} }
@media (max-width:520px){ .f-cols{grid-template-columns:1fr} }
@media (prefers-color-scheme: dark){ footer.site{background:#0d1e37} }

/* ---------- menu tài khoản trên header (auth.js) ---------- */
.umenu{position:relative;margin-left:6px;flex:none}
.ubtn{display:flex;align-items:center;gap:8px;border:2px solid var(--hair);background:#fff;border-radius:24px;padding:3px 10px 3px 3px;
  cursor:pointer;font:inherit;font-weight:800;color:var(--navy)}
.ubtn:hover{background:var(--soft)}
.uav{width:32px;height:32px;border-radius:50%;object-fit:cover;background:var(--teal);color:#fff;display:inline-grid;place-items:center;
  font-size:12.5px;font-weight:900;flex:none}
.uname{max-width:150px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:14px}
.ucaret{color:var(--text-2);font-size:11px}
.udrop{position:absolute;right:0;top:calc(100% + 8px);min-width:250px;background:#fff;border:2px solid var(--hair);border-radius:14px;
  box-shadow:0 12px 28px rgba(20,42,76,.16);padding:8px;z-index:40}
.udrop .uhead{display:flex;gap:10px;align-items:center;padding:6px 8px 10px;border-bottom:1px solid var(--hair);margin-bottom:6px}
.udrop .uhead b{display:block;color:var(--navy);font-size:15px}
.udrop .uhead small{display:block;color:var(--text-2);font-size:12.5px;word-break:break-all}
.udrop a,.udrop button{display:block;width:100%;text-align:left;padding:9px 10px;border-radius:10px;color:var(--text);text-decoration:none;
  font:inherit;font-weight:700;font-size:14.5px;background:none;border:0;cursor:pointer}
.udrop a:hover,.udrop button:hover{background:var(--soft)}
@media (prefers-color-scheme: dark){
  .ubtn{background:#1b2430;color:#e6edf6}
  .udrop{background:#1b2430} .udrop .uhead b{color:#e6edf6}
}
@media (max-width:720px){
  .brand{order:1} .umenu{order:2;margin-left:auto} .mainnav{order:3}
  .uname,.ucaret{display:none} .ubtn{padding:3px}
}
.gbtns{display:flex;gap:10px;margin-left:6px;flex:none}
@media (max-width:720px){ .gbtns{order:2;margin-left:auto;gap:8px} .gbtns .btn3d.sm{padding:8px 12px;font-size:12px} }
@media (max-width:440px){ /* logo + 2 nút cùng một hàng trên điện thoại */
  .gbtns{gap:6px} .gbtns .btn3d.sm{padding:7px 9px;font-size:11px;letter-spacing:.04em}
  .site-in:has(.gbtns) .brand{min-width:0} .site-in:has(.gbtns) .brand img{width:34px;height:34px}
  .site-in:has(.gbtns) .brand .bt b{font-size:14px} .site-in:has(.gbtns) .brand .bt small{font-size:9px;letter-spacing:.26em} }
/* nhãn nhà cung cấp đăng nhập (dùng ở tài khoản + quản trị) */
.pv{display:inline-flex;align-items:center;gap:5px;font-size:12.5px;font-weight:800;border-radius:20px;padding:2px 9px;background:var(--soft);color:var(--text)}
.pv svg{width:14px;height:14px}