/* CSS dùng chung cho các TRANG NỘI DUNG công khai của Visually Anything.
   Vì sao tách riêng: landing.html giữ CSS nhúng của nó; các trang này cần bản gọn, độc lập
   — sửa trang nội dung KHÔNG đụng tới trang chủ (và ngược lại).
   Bảng màu lấy đúng từ landing.html để hai nơi nhìn như một hệ. */
:root{
  --tim-900:#2d0f52; --tim-700:#4c1d95; --tim-600:#5b21b6; --tim-500:#6d28d9; --tim-400:#8b5cf6;
  --tim-100:#ede9fe; --tim-50:#f5f3ff;
  --muc:#1f1235; --muc-nhat:#5b5470; --vien:#e6e1f2; --nen:#ffffff; --nen-phu:#faf8ff;
  --bong:0 1px 2px rgba(45,15,82,.06), 0 8px 24px rgba(45,15,82,.08);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:'Segoe UI',system-ui,-apple-system,Arial,sans-serif;color:var(--muc);
  background:var(--nen);line-height:1.7;-webkit-font-smoothing:antialiased}
a{color:var(--tim-600)}
.boc{max-width:820px;margin:0 auto;padding:0 24px}

header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.92);
  backdrop-filter:blur(10px);border-bottom:1px solid var(--vien)}
.nav{max-width:1120px;margin:0 auto;padding:0 24px;display:flex;align-items:center;gap:16px;height:66px}
.logo{display:flex;align-items:center;gap:11px;font-weight:800;font-size:19px;color:var(--tim-900);text-decoration:none}
.logo svg{width:32px;height:32px;border-radius:8px;flex:none}
.nav .lien-ket{margin-left:auto;display:flex;align-items:center;gap:20px;font-weight:600;font-size:15px}
.nav .lien-ket a{text-decoration:none;color:var(--muc-nhat)}
.nav .lien-ket a:hover{color:var(--tim-600)}
.nut{display:inline-block;padding:10px 18px;border-radius:11px;font-weight:700;text-decoration:none;
  background:linear-gradient(135deg,var(--tim-600),var(--tim-500));color:#fff;font-size:15px}
.nut:hover{filter:brightness(1.08)}

main{padding:44px 0 8px}
.muc-luc{background:var(--tim-50);border:1px solid var(--vien);border-radius:14px;padding:18px 22px;margin:0 0 34px}
.muc-luc b{display:block;font-size:13.5px;letter-spacing:1.1px;text-transform:uppercase;color:var(--tim-600);margin-bottom:8px}
.muc-luc ul{list-style:none;display:flex;flex-wrap:wrap;gap:6px 18px}
.muc-luc a{font-size:15px;text-decoration:none}
.muc-luc a:hover{text-decoration:underline}

h1{font-size:clamp(28px,4.2vw,42px);line-height:1.18;letter-spacing:-1px;margin-bottom:14px}
h2{font-size:clamp(21px,2.6vw,27px);letter-spacing:-.5px;margin:40px 0 12px}
h3{font-size:19px;margin:26px 0 8px}
p{margin:10px 0;color:#2c2340}
.sao{color:var(--muc-nhat);font-size:14.5px;margin-bottom:20px}
ul.danh-sach,ol.danh-sach{margin:10px 0 10px 22px}
ul.danh-sach li,ol.danh-sach li{margin:7px 0}
b,strong{color:var(--tim-900)}
code{background:var(--tim-50);border:1px solid var(--vien);border-radius:6px;padding:1px 6px;
  font-family:ui-monospace,Consolas,monospace;font-size:14.5px;color:var(--tim-700)}
pre{background:#1f1235;color:#eae4ff;border-radius:12px;padding:16px 18px;overflow:auto;margin:14px 0;font-size:14px;line-height:1.6}
pre code{background:none;border:none;color:inherit;padding:0}
.bang{width:100%;border-collapse:collapse;margin:16px 0;font-size:15px}
.bang th,.bang td{border:1px solid var(--vien);padding:9px 12px;text-align:left;vertical-align:top}
.bang th{background:var(--tim-50);color:var(--tim-900)}
.ghi-chu{background:var(--nen-phu);border-left:4px solid var(--tim-400);border-radius:0 10px 10px 0;
  padding:12px 16px;margin:16px 0;font-size:15px;color:#2c2340}
.hop-cta{background:linear-gradient(135deg,var(--tim-700),var(--tim-500));border-radius:16px;
  padding:26px 28px;margin:40px 0 44px;color:#fff}
.hop-cta h2{color:#fff;margin:0 0 8px}
.hop-cta p{color:#e9e1ff;margin:0 0 16px}
.hop-cta .nut{background:#fff;color:var(--tim-700)}
.cau-hoi details{border:1px solid var(--vien);border-radius:12px;padding:12px 16px;margin:10px 0;background:#fff}
.cau-hoi summary{cursor:pointer;font-weight:700}
.cau-hoi details p{margin-top:8px;color:var(--muc-nhat)}
footer{border-top:1px solid var(--vien);margin-top:20px;padding:26px 0;background:var(--nen-phu)}
footer .boc{display:flex;flex-wrap:wrap;gap:12px;align-items:center;font-size:14.5px;color:var(--muc-nhat)}
footer a{text-decoration:none}
footer a:hover{text-decoration:underline}
.lien-quan{display:flex;flex-wrap:wrap;gap:12px;margin:26px 0}
.lien-quan a{border:1px solid var(--vien);border-radius:11px;padding:11px 16px;text-decoration:none;
  font-weight:600;background:#fff;font-size:15px}
.lien-quan a:hover{border-color:var(--tim-400);background:var(--tim-50)}
@media(max-width:640px){
  .nav{height:auto;padding:12px 18px;flex-wrap:wrap;gap:10px}
  .nav .lien-ket{width:100%;margin-left:0;gap:14px;font-size:14px}
  main{padding:28px 0 4px}
  h2{margin-top:30px}
}