:root {
  --xanh-dam: #0b2545;
  --xanh: #1363df;
  --cam: #ff7a1a;
  --nen: #ffffff;
  --nen-nhat: #f3f6fb;
  --chu: #16202e;
  --chu-phu: #55657a;
  --vien: #dde4ee;
}
@media (prefers-color-scheme: dark) {
  :root { --nen: #0e1520; --nen-nhat: #151f2e; --chu: #e8eef6; --chu-phu: #a3b1c2; --vien: #263447; }
}
* { box-sizing: border-box; }
body { margin: 0; font: 17px/1.65 "Segoe UI", system-ui, sans-serif; color: var(--chu); background: var(--nen); }
.khung { max-width: 1040px; margin: 0 auto; padding: 0 16px; }
a { color: var(--xanh); }
h1, h2, h3 { line-height: 1.25; }

.dau-trang { position: sticky; top: 0; background: var(--nen); border-bottom: 1px solid var(--vien); z-index: 5; }
.dau-trang .khung { display: flex; justify-content: space-between; align-items: center; height: 60px; }
.logo { font-weight: 800; font-size: 20px; color: var(--chu); text-decoration: none; }
.logo span { color: var(--cam); }
nav a { margin-left: 18px; color: var(--chu-phu); text-decoration: none; font-weight: 600; }

.hero { background: linear-gradient(160deg, var(--xanh-dam), var(--xanh)); color: #fff; padding: 72px 0 80px; }
.hero h1 { font-size: clamp(30px, 5vw, 48px); margin: 8px 0 16px; max-width: 760px; }
.hero em { font-style: normal; color: #ffd2ad; }
.hero .mo-ta { max-width: 640px; opacity: .92; }
.nhan { display: inline-block; background: var(--cam); color: #fff; padding: 4px 14px; border-radius: 99px; font-weight: 700; font-size: 14px; margin: 0; }

.nut { display: inline-block; background: var(--cam); color: #fff; border: 0; border-radius: 10px; padding: 12px 22px; font: 700 16px "Segoe UI", sans-serif; text-decoration: none; cursor: pointer; }
.nut:hover { filter: brightness(1.07); }

.muc { padding: 64px 0; }
.muc-nhat { background: var(--nen-nhat); }
.hai-cot { display: grid; grid-template-columns: 3fr 2fr; gap: 40px; align-items: start; }
.the-gia-tri { list-style: none; padding: 0; margin: 0; display: grid; gap: 12px; }
.the-gia-tri li { border: 1px solid var(--vien); border-left: 4px solid var(--cam); border-radius: 10px; padding: 14px 16px; }
.the-gia-tri b { display: block; }
.the-gia-tri span { color: var(--chu-phu); font-size: 15px; }

.san-pham { display: grid; grid-template-columns: 220px 1fr; gap: 28px; background: var(--nen); border: 1px solid var(--vien); border-radius: 16px; padding: 24px; }
.bia-sp { background: linear-gradient(160deg, var(--xanh-dam), var(--xanh)); color: #fff; border-radius: 12px; display: flex; flex-direction: column; align-items: center; justify-content: center; font-size: 84px; font-weight: 900; min-height: 220px; }
.bia-sp small { font-size: 18px; font-weight: 600; }
.san-pham h3 { margin-top: 0; }
.luu-y { color: var(--chu-phu); font-size: 14px; }
.gia-mua { display: flex; align-items: center; gap: 20px; margin-top: 12px; }
.gia { font-size: 30px; font-weight: 800; color: var(--cam); }

details { border: 1px solid var(--vien); border-radius: 10px; padding: 12px 16px; margin-bottom: 10px; }
summary { font-weight: 700; cursor: pointer; }
.chan-trang { border-top: 1px solid var(--vien); padding: 24px 0; color: var(--chu-phu); font-size: 14px; }

.hop-thoai { position: fixed; inset: 0; background: rgba(5, 12, 24, .6); display: flex; align-items: center; justify-content: center; padding: 16px; z-index: 10; }
.hop-thoai[hidden] { display: none; }
.the-hop-thoai { background: var(--nen); border-radius: 16px; padding: 24px; width: 100%; max-width: 420px; position: relative; max-height: 92vh; overflow: auto; }
.dong { position: absolute; top: 8px; right: 12px; border: 0; background: none; font-size: 28px; color: var(--chu-phu); cursor: pointer; }
label { display: block; font-weight: 600; margin-bottom: 12px; }
input { display: block; width: 100%; margin-top: 4px; padding: 10px 12px; border: 1px solid var(--vien); border-radius: 8px; font: inherit; background: var(--nen); color: var(--chu); }
.loi { color: #d33; min-height: 1em; }
#anh-qr { width: 100%; max-width: 280px; display: block; margin: 0 auto 12px; border-radius: 8px; background: #fff; }
dl { display: grid; grid-template-columns: auto 1fr; gap: 4px 12px; }
dt { color: var(--chu-phu); }
dd { margin: 0; word-break: break-word; }
.cho { font-weight: 700; }

@media (max-width: 720px) {
  .hai-cot, .san-pham { grid-template-columns: 1fr; }
  nav a { margin-left: 12px; font-size: 14px; }
  .bia-sp { min-height: 140px; font-size: 60px; }
}