:root {
  --xanh: #1F3A5F;
  --xanh-dam: #152A45;
  --cam: #F28C28;
  --cam-dam: #9A4F08;
  --nen: #F7F8FA;
  --chu: #1A1F27;
  --chu-phu: #4A5361;
  --vien: #DDE2E8;
  --trang: #FFFFFF;
  --xanh-la: #1E7B4C;
  --do: #B42318;
  --bo-goc: 12px;
  --bong: 0 6px 20px rgba(21, 42, 69, .08);
}

*, *::before, *::after { box-sizing: border-box; }

[hidden] { display: none !important; }

html { scroll-behavior: smooth; scroll-padding-top: 72px; }

body {
  margin: 0;
  font-family: "Be Vietnam Pro", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 1rem;
  line-height: 1.6;
  color: var(--chu);
  background: var(--nen);
}

img, svg { max-width: 100%; display: block; }

a { color: var(--xanh); }

:focus-visible { outline: 3px solid var(--cam); outline-offset: 2px; }

.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 16px; }

/* ---------- Tiện ích ---------- */
.an-chu { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.bo-qua { position: absolute; left: 16px; top: -48px; z-index: 100; padding: 8px 14px; background: var(--cam); color: var(--chu); border-radius: 8px; font-weight: 600; }
.bo-qua:focus { top: 8px; }
.nhan { margin: 0 0 8px; font-size: .8125rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--cam-dam); }
h1, h2, h3 { line-height: 1.2; margin: 0 0 12px; }
h2 { font-size: clamp(1.6rem, 1.2rem + 1.8vw, 2.4rem); color: var(--xanh-dam); }
h3 { font-size: 1.125rem; }

/* ---------- Nút ---------- */
.nut { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 48px; padding: 0 24px; border: 2px solid transparent; border-radius: 10px; font: inherit; font-weight: 700; text-decoration: none; cursor: pointer; transition: transform .15s ease, background-color .15s ease; }
.nut:hover { transform: translateY(-2px); }
.nut:active { transform: translateY(0); }
.nut--cam { background: var(--cam); color: var(--chu); box-shadow: 0 4px 0 var(--cam-dam); }
.nut--cam:hover { background: #F59A3E; }
.nut--vien { border-color: rgba(255, 255, 255, .7); color: var(--trang); }
.nut--vien:hover { background: rgba(255, 255, 255, .1); }
.nut--vien-toi { border-color: var(--do); color: var(--do); background: var(--trang); }
.nut--nho { min-height: 40px; padding: 0 16px; font-size: .9375rem; box-shadow: none; }
.nut[disabled] { opacity: .7; cursor: progress; transform: none; }

/* ---------- Đầu trang ---------- */
.dau-trang { position: sticky; top: 0; z-index: 50; background: rgba(255, 255, 255, .96); border-bottom: 1px solid var(--vien); backdrop-filter: blur(8px); }
.dau-trang__trong { display: flex; align-items: center; gap: 16px; min-height: 64px; }
.logo { display: flex; align-items: center; gap: 10px; color: var(--xanh-dam); text-decoration: none; font-size: 1.0625rem; margin-right: auto; }
.menu { display: none; }
.menu a { color: var(--chu); text-decoration: none; font-weight: 600; padding: 8px 4px; }
.menu a:hover { color: var(--cam-dam); }
.nut-menu { width: 44px; height: 44px; border: 1px solid var(--vien); border-radius: 10px; background: var(--trang); cursor: pointer; display: grid; place-items: center; }
.nut-menu__vach, .nut-menu__vach::before, .nut-menu__vach::after { display: block; width: 20px; height: 2px; background: var(--xanh-dam); content: ""; transition: transform .2s ease; }
.nut-menu__vach { position: relative; }
.nut-menu__vach::before { position: absolute; top: -6px; }
.nut-menu__vach::after { position: absolute; top: 6px; }
.nut-menu[aria-expanded="true"] .nut-menu__vach { background: transparent; }
.nut-menu[aria-expanded="true"] .nut-menu__vach::before { transform: translateY(6px) rotate(45deg); }
.nut-menu[aria-expanded="true"] .nut-menu__vach::after { transform: translateY(-6px) rotate(-45deg); }
.menu.mo { display: flex; flex-direction: column; position: absolute; left: 0; right: 0; top: 64px; padding: 8px 16px 16px; background: var(--trang); border-bottom: 1px solid var(--vien); box-shadow: var(--bong); }
.menu.mo a { padding: 12px 4px; border-bottom: 1px solid var(--vien); }
.goi-ngay { display: none; }

/* ---------- Hero ---------- */
.hero { position: relative; overflow: hidden; color: var(--trang); background:
  linear-gradient(rgba(255, 255, 255, .05) 1px, transparent 1px) 0 0 / 32px 32px,
  linear-gradient(90deg, rgba(255, 255, 255, .05) 1px, transparent 1px) 0 0 / 32px 32px,
  radial-gradient(120% 90% at 100% 0%, #2B5384 0%, var(--xanh) 45%, var(--xanh-dam) 100%); }
.hero::after { content: ""; position: absolute; right: -120px; bottom: -120px; width: 360px; height: 360px; border: 40px dashed rgba(242, 140, 40, .25); border-radius: 50%; }
.hero__trong { position: relative; z-index: 1; padding-top: 56px; padding-bottom: 48px; }
.hero .nhan { color: var(--cam); }
.hero h1 { font-size: clamp(2rem, 1.3rem + 3.6vw, 3.6rem); max-width: 15ch; letter-spacing: -.01em; }
.hero__mo-ta { max-width: 56ch; font-size: 1.0625rem; color: #DCE5F0; margin: 0 0 28px; }
.hero__nut { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 40px; }
.con-so { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin: 0; max-width: 560px; }
.con-so div { padding: 14px 12px; border-left: 3px solid var(--cam); background: rgba(255, 255, 255, .06); }
.con-so dt { font-size: .8125rem; color: #C9D5E3; }
.con-so dd { margin: 4px 0 0; font-size: clamp(1.3rem, 1rem + 1.4vw, 1.9rem); font-weight: 700; }
.ghi-chu-so { margin: 8px 0 0; font-size: .8125rem; color: #C9D5E3; }

/* ---------- Mục chung ---------- */
.muc { padding: 64px 0; }
.muc__mo-ta { max-width: 60ch; color: var(--chu-phu); margin: 0 0 32px; }
.muc--nhat { background: #EEF1F5; }
.muc--toi { background: var(--xanh-dam); color: var(--trang); }
.muc--toi h2 { color: var(--trang); }
.muc--toi .nhan { color: var(--cam); }

/* ---------- Sản phẩm ---------- */
.luoi-san-pham { display: grid; gap: 16px; }
.the-san-pham { padding: 24px; background: var(--trang); border: 1px solid var(--vien); border-radius: var(--bo-goc); transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease; }
.the-san-pham:hover { transform: translateY(-4px); box-shadow: var(--bong); border-color: var(--cam); }
.the-san-pham p { color: var(--chu-phu); margin: 0 0 12px; }
.the-san-pham ul { margin: 0; padding: 0; list-style: none; font-size: .9375rem; }
.the-san-pham li { padding: 6px 0 6px 18px; border-top: 1px dashed var(--vien); position: relative; }
.the-san-pham li::before { content: ""; position: absolute; left: 0; top: 15px; width: 8px; height: 8px; background: var(--cam); }
.bieu-tuong { width: 48px; height: 48px; color: var(--xanh); margin-bottom: 16px; }
.the-san-pham--lon { background: var(--xanh); color: var(--trang); border-color: var(--xanh); }
.the-san-pham--lon p { color: #DCE5F0; }
.the-san-pham--lon .bieu-tuong { color: var(--cam); width: 64px; height: 64px; }
.the-san-pham--lon li { border-top-color: rgba(255, 255, 255, .2); }

/* ---------- Lợi ích ---------- */
.loi-ich { display: grid; gap: 16px; margin: 32px 0 0; padding: 0; list-style: none; counter-reset: loi-ich; }
.loi-ich li { counter-increment: loi-ich; padding: 24px; border: 1px solid rgba(255, 255, 255, .15); border-radius: var(--bo-goc); }
.loi-ich li::before { content: "0" counter(loi-ich); display: block; font-weight: 700; color: var(--cam); margin-bottom: 8px; }
.loi-ich p { margin: 0; color: #C9D5E3; }

/* ---------- Ngành ---------- */
.nganh { display: flex; flex-wrap: wrap; gap: 12px; margin: 24px 0 0; padding: 0; list-style: none; }
.nganh li { padding: 12px 20px; border-radius: 999px; background: var(--trang); border: 1px solid var(--vien); font-weight: 600; color: var(--xanh-dam); }

/* ---------- Quy trình ---------- */
.buoc { display: grid; gap: 16px; margin: 32px 0 0; padding: 0; list-style: none; }
.buoc li { position: relative; padding: 24px 24px 24px 88px; background: var(--trang); border-radius: var(--bo-goc); border: 1px solid var(--vien); }
.buoc__so { position: absolute; left: 24px; top: 20px; font-size: 2.25rem; font-weight: 700; color: var(--cam-dam); line-height: 1; }
.buoc p { margin: 0; color: var(--chu-phu); }

/* ---------- Báo giá ---------- */
.bao-gia { display: grid; gap: 32px; }
.form { display: grid; gap: 16px; padding: 24px; background: var(--trang); border: 1px solid var(--vien); border-radius: var(--bo-goc); box-shadow: var(--bong); }
.o label { display: block; font-weight: 600; margin-bottom: 6px; }
.o label span { color: var(--do); }
.o input, .o select, .o textarea { width: 100%; min-height: 48px; padding: 10px 14px; font: inherit; color: var(--chu); background: var(--nen); border: 1px solid #8A95A3; border-radius: 8px; }
.o input:focus, .o select:focus, .o textarea:focus { outline: 3px solid rgba(242, 140, 40, .45); border-color: var(--cam-dam); }
.o [aria-invalid="true"] { border-color: var(--do); background: #FEF3F2; }
.loi { margin: 6px 0 0; min-height: 1.2em; font-size: .875rem; color: var(--do); }
.ghi-chu-form { margin: 0; font-size: .8125rem; color: var(--chu-phu); }
.thong-bao { padding: 24px; border-radius: var(--bo-goc); border: 2px solid; }
.thong-bao p { margin: 0 0 12px; }
.thong-bao--tot { border-color: var(--xanh-la); background: #ECFDF3; color: #054F31; }
.thong-bao--loi { border-color: var(--do); background: #FEF3F2; color: #7A271A; }

/* ---------- Hỏi đáp ---------- */
.hoi-dap { max-width: 860px; }
.hoi-dap details { background: var(--trang); border: 1px solid var(--vien); border-radius: 10px; margin-top: 12px; }
.hoi-dap summary { padding: 16px 48px 16px 20px; font-weight: 600; cursor: pointer; list-style: none; position: relative; }
.hoi-dap summary::-webkit-details-marker { display: none; }
.hoi-dap summary::after { content: "+"; position: absolute; right: 20px; top: 12px; font-size: 1.5rem; color: var(--cam-dam); }
.hoi-dap details[open] summary::after { content: "–"; }
.hoi-dap details p { margin: 0; padding: 0 20px 16px; color: var(--chu-phu); }

/* ---------- Chân trang ---------- */
.chan-trang { background: var(--xanh-dam); color: #C9D5E3; padding: 48px 0 96px; }
.chan-trang a { color: var(--trang); }
.chan-trang__luoi { display: grid; gap: 24px; }
.chan-trang__ten { font-size: 1.25rem; font-weight: 700; color: var(--trang); margin: 0 0 8px; }
.chan-trang address { font-style: normal; line-height: 1.9; }
.mien-tru { margin: 32px 0 0; padding: 12px 16px 0; border-top: 1px solid rgba(255, 255, 255, .15); text-align: center; font-size: .875rem; }

/* ---------- Nút nổi (điện thoại) ---------- */
.nut-noi { position: fixed; right: 16px; bottom: 16px; z-index: 60; display: flex; flex-direction: column; gap: 10px; }
.nut-noi a { width: 52px; height: 52px; display: grid; place-items: center; border-radius: 50%; color: var(--trang); text-decoration: none; font-weight: 700; font-size: .8125rem; box-shadow: 0 6px 16px rgba(0, 0, 0, .25); }
.nut-noi__goi { background: var(--xanh-la); }
.nut-noi__zalo { background: #0055D4; }

/* ---------- Màn rộng ---------- */
@media (min-width: 768px) {
  .nut-menu { display: none; }
  .menu, .menu.mo { display: flex; gap: 20px; position: static; padding: 0; box-shadow: none; border: 0; flex-direction: row; background: none; }
  .menu.mo a { border: 0; padding: 8px 4px; }
  .goi-ngay { display: inline-flex; }
  .nut-noi { display: none; }
  .hero__trong { padding-top: 96px; padding-bottom: 80px; }
  .muc { padding: 88px 0; }
  .luoi-san-pham { grid-template-columns: repeat(2, 1fr); }
  .the-san-pham--lon { grid-row: span 2; }
  .loi-ich { grid-template-columns: repeat(2, 1fr); }
  .buoc { grid-template-columns: repeat(3, 1fr); }
  .buoc li { padding: 72px 24px 24px; }
  .buoc__so { top: 24px; }
  .form { grid-template-columns: 1fr 1fr; }
  .o--rong { grid-column: 1 / -1; }
  .chan-trang { padding-bottom: 48px; }
  .chan-trang__luoi { grid-template-columns: 1fr 1fr; }
}

@media (min-width: 1100px) {
  .luoi-san-pham { grid-template-columns: repeat(3, 1fr); }
  .loi-ich { grid-template-columns: repeat(4, 1fr); }
  .bao-gia { grid-template-columns: 5fr 7fr; align-items: start; }
  .bao-gia .thong-bao { grid-column: 2; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}