/* ==========================================================
   BẢNG ĐIỀU CHỈNH: SỬA Ở ĐÂY
   Chỉ đổi giá trị sau dấu hai chấm. Không xóa dấu chấm phẩy.
   ========================================================== */
:root {
  --mau-chinh: #7F0104;      /* đỏ đô: nút chính, tiêu đề */
  --mau-nen: #FEFBF4;        /* nền trang */
  --font-tieu-de: 'Baloo 2', 'Segoe UI', Tahoma, sans-serif;
  --font-than: 'Be Vietnam Pro', 'Segoe UI', Tahoma, sans-serif;
  --khoang-cach: 20px;       /* lề hai bên trên điện thoại */

  --mau-chinh-dam: #5E0003;  /* đỏ đô khi rê chuột */
  --mau-nen-phu: #FDF3E9;    /* nền các khối xen kẽ */
  --mau-chu: #2B1A17;        /* chữ nội dung */
  --mau-chu-phu: #6B4E48;    /* chữ chú thích */
  --bo-goc: 22px;            /* bo góc thẻ */
}
/* ============ HẾT BẢNG ĐIỀU CHỈNH ============ */

/* Font nằm ngay trong thư mục assets/fonts, không tải từ dịch vụ ngoài */
@font-face{font-family:'Baloo 2';font-style:normal;font-weight:700;font-display:swap;src:url(fonts/baloo-2-vietnamese-700-normal.woff2) format('woff2');unicode-range:U+0102-0103,U+0110-0111,U+0128-0129,U+0168-0169,U+01A0-01A1,U+01AF-01B0,U+0300-0301,U+0303-0304,U+0308-0309,U+0323,U+0329,U+1EA0-1EF9,U+20AB;}
@font-face{font-family:'Baloo 2';font-style:normal;font-weight:700;font-display:swap;src:url(fonts/baloo-2-latin-700-normal.woff2) format('woff2');unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD;}
@font-face{font-family:'Baloo 2';font-style:normal;font-weight:800;font-display:swap;src:url(fonts/baloo-2-vietnamese-800-normal.woff2) format('woff2');unicode-range:U+0102-0103,U+0110-0111,U+0128-0129,U+0168-0169,U+01A0-01A1,U+01AF-01B0,U+0300-0301,U+0303-0304,U+0308-0309,U+0323,U+0329,U+1EA0-1EF9,U+20AB;}
@font-face{font-family:'Baloo 2';font-style:normal;font-weight:800;font-display:swap;src:url(fonts/baloo-2-latin-800-normal.woff2) format('woff2');unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD;}
@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:400;font-display:swap;src:url(fonts/be-vietnam-pro-vietnamese-400-normal.woff2) format('woff2');unicode-range:U+0102-0103,U+0110-0111,U+0128-0129,U+0168-0169,U+01A0-01A1,U+01AF-01B0,U+0300-0301,U+0303-0304,U+0308-0309,U+0323,U+0329,U+1EA0-1EF9,U+20AB;}
@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:400;font-display:swap;src:url(fonts/be-vietnam-pro-latin-400-normal.woff2) format('woff2');unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD;}
@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:500;font-display:swap;src:url(fonts/be-vietnam-pro-vietnamese-500-normal.woff2) format('woff2');unicode-range:U+0102-0103,U+0110-0111,U+0128-0129,U+0168-0169,U+01A0-01A1,U+01AF-01B0,U+0300-0301,U+0303-0304,U+0308-0309,U+0323,U+0329,U+1EA0-1EF9,U+20AB;}
@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:500;font-display:swap;src:url(fonts/be-vietnam-pro-latin-500-normal.woff2) format('woff2');unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD;}
@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:600;font-display:swap;src:url(fonts/be-vietnam-pro-vietnamese-600-normal.woff2) format('woff2');unicode-range:U+0102-0103,U+0110-0111,U+0128-0129,U+0168-0169,U+01A0-01A1,U+01AF-01B0,U+0300-0301,U+0303-0304,U+0308-0309,U+0323,U+0329,U+1EA0-1EF9,U+20AB;}
@font-face{font-family:'Be Vietnam Pro';font-style:normal;font-weight:600;font-display:swap;src:url(fonts/be-vietnam-pro-latin-600-normal.woff2) format('woff2');unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD;}
@font-face{font-family:'Ma Shan Zheng';font-style:normal;font-weight:400;font-display:swap;src:url(fonts/ma-shan-zheng-thuong-hieu.woff2) format('woff2');unicode-range:U+6A31,U+8212,U+6C49,U+8BED;}


:root {
  --trang: #FFFFFF;
  --vien: #EAD9CC;
  --vien-nhat: #F1E3D8;
  --vien-o-nhap: #9C7F76;
  --hong-nhan: #F2D8D7;
  --hong-nhat: #FBE9E4;
  --vang-nhat: #F6E7C8;
  --vang-kem: #F6DFB0;
  --vang-dam: #7A5310;
  --font-han: 'Ma Shan Zheng', 'Kaiti SC', 'STKaiti', 'KaiTi', serif;
}

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body {
  margin: 0;
  background: var(--mau-nen);
  color: var(--mau-chu);
  font-family: var(--font-than);
  font-size: 16px;
  line-height: 1.55;
}
img { max-width: 100%; height: auto; display: block; }
h1, h2, h3, p, ul, ol, fieldset { margin: 0; padding: 0; }
ul, ol { list-style: none; }
a { color: var(--mau-chinh); }
a:hover { color: var(--mau-chinh-dam); }
:focus-visible { outline: 3px solid var(--mau-chinh); outline-offset: 2px; border-radius: 6px; }
.chan-trang :focus-visible, .lop--sap :focus-visible { outline-color: var(--vang-kem); }
section[id] { scroll-margin-top: 76px; }

.khung { max-width: 1200px; margin: 0 auto; padding-left: var(--khoang-cach); padding-right: var(--khoang-cach); }
.an-voi-mat { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.ic { width: 20px; height: 20px; flex-shrink: 0; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

/* ---------- Thanh đầu ---------- */
.dau-trang { position: sticky; top: 0; z-index: 20; background: var(--mau-nen); border-bottom: 1px solid var(--vien); }
.dau-trang .khung { min-height: 64px; display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 0 16px; padding-right: 8px; }
.thuong-hieu { display: flex; align-items: center; gap: 10px; text-decoration: none; padding: 8px 0; }
.thuong-hieu img { width: 40px; height: 40px; border-radius: 9px; object-fit: cover; }
.thuong-hieu-ten { display: block; font-family: var(--font-tieu-de); font-weight: 700; font-size: 18px; line-height: 1.1; color: var(--mau-chinh); }
.thuong-hieu-han { display: block; font-family: var(--font-han); font-size: 14px; line-height: 1.2; letter-spacing: 3px; color: var(--vang-dam); }
.nut-menu { display: none; width: 48px; height: 48px; border: 0; background: transparent; border-radius: 12px; color: var(--mau-chinh); cursor: pointer; align-items: center; justify-content: center; }
.nut-menu .ic { width: 24px; height: 24px; stroke-width: 2.2; }
.menu { width: 100%; display: flex; flex-direction: column; padding: 4px 12px 14px 0; }
.menu a { min-height: 48px; display: flex; align-items: center; color: var(--mau-chu); text-decoration: none; font-weight: 500; border-top: 1px solid var(--vien-nhat); }
.menu a:hover { color: var(--mau-chinh); }
.menu .nut { display: none; }
.js .nut-menu { display: flex; }
.js .menu { display: none; }
.js .menu.mo { display: flex; }

/* ---------- Nút, nhãn ---------- */
.nut { min-height: 52px; padding: 8px 22px; display: inline-flex; align-items: center; justify-content: center; gap: 10px; border: 2px solid var(--mau-chinh); border-radius: 999px; font-family: inherit; font-weight: 600; font-size: 16px; line-height: 1.25; text-align: center; text-decoration: none; cursor: pointer; }
.nut--chinh { background: var(--mau-chinh); color: var(--trang); }
.nut--chinh:hover { background: var(--mau-chinh-dam); border-color: var(--mau-chinh-dam); color: var(--trang); }
.nut--vien { background: var(--mau-nen); color: var(--mau-chinh); }
.nut--vien:hover { background: var(--hong-nhat); color: var(--mau-chinh-dam); }
.nut--lon { min-height: 56px; }
.nut--rong { display: flex; width: 100%; }
.lien-ket-mui-ten { min-height: 48px; display: inline-flex; align-items: center; gap: 8px; font-weight: 600; font-size: 16px; text-decoration: none; }
.lien-ket-mui-ten .ic { width: 18px; height: 18px; stroke-width: 2.2; }
.nhan { display: inline-block; padding: 4px 13px; background: var(--hong-nhan); color: var(--mau-chinh); border-radius: 999px; font-size: 13px; font-weight: 600; white-space: nowrap; }
.nhan--sang { background: var(--hong-nhat); }
.huy-hieu { display: inline-block; padding: 3px 12px; background: var(--vang-nhat); color: var(--vang-dam); border-radius: 999px; font-size: 12px; font-weight: 600; letter-spacing: 0.8px; text-transform: uppercase; white-space: nowrap; }
.vong-bieu-tuong { width: 40px; height: 40px; flex-shrink: 0; border-radius: 50%; background: var(--mau-chinh); color: var(--trang); display: flex; align-items: center; justify-content: center; }
.vong-bieu-tuong--vang { background: var(--vang-nhat); color: var(--vang-dam); }

/* ---------- Khối chung ---------- */
.khoi { padding: 40px 0; }
.khoi--phu { background: var(--mau-nen-phu); }
.nhan-khoi { font-size: 13px; font-weight: 600; letter-spacing: 1.6px; text-transform: uppercase; color: var(--vang-dam); }
h2 { margin-top: 6px; font-family: var(--font-tieu-de); font-weight: 800; font-size: 28px; line-height: 1.15; color: var(--mau-chinh); }
h3 { font-family: var(--font-tieu-de); font-weight: 800; line-height: 1.1; color: var(--mau-chinh); }
.mo-ta-khoi { margin-top: 10px; font-size: 16px; color: var(--mau-chu-phu); }
.the { background: var(--trang); border: 1px solid var(--vien); border-radius: var(--bo-goc); }

/* ---------- Mở đầu ---------- */
.mo-dau .khung { padding-top: 24px; padding-bottom: 28px; display: grid; grid-template-columns: minmax(0, 1fr); grid-template-areas: "nhan" "tieu-de" "mo-ta" "co-giao" "nut"; }
.mo-dau-nhan { grid-area: nhan; justify-self: start; display: flex; align-items: center; gap: 8px; min-height: 32px; padding: 0 14px; border: 1.5px solid var(--mau-chinh); border-radius: 999px; font-size: 13px; font-weight: 600; letter-spacing: 0.4px; color: var(--mau-chinh); }
.mo-dau-nhan .ic { width: 15px; height: 15px; stroke-width: 2.2; }
h1 { grid-area: tieu-de; margin-top: 16px; font-family: var(--font-tieu-de); font-weight: 800; font-size: 38px; line-height: 1.1; letter-spacing: -0.3px; color: var(--mau-chinh); }
h1 .gach-nen { box-shadow: inset 0 -0.3em 0 #F3DDB0; }
.mo-dau-mo-ta { grid-area: mo-ta; margin-top: 14px; color: var(--mau-chu-phu); }
.mo-dau-co-giao { grid-area: co-giao; margin-top: 20px; padding: 12px; display: flex; align-items: center; gap: 14px; background: var(--trang); border: 1px solid var(--vien); border-radius: 20px; }
.mo-dau-co-giao img { width: 72px; height: 84px; flex-shrink: 0; object-fit: cover; border-radius: 36px 36px 12px 12px; background: #EBC9C0; }
.mo-dau-co-giao-chu { display: flex; flex-direction: column; gap: 3px; min-width: 0; font-size: 14px; line-height: 1.4; color: var(--mau-chu-phu); }
.mo-dau-co-giao-chu strong { font-family: var(--font-tieu-de); font-weight: 700; font-size: 18px; line-height: 1.2; color: var(--mau-chu); }
.mo-dau-nut { grid-area: nut; margin-top: 20px; display: flex; flex-direction: column; align-items: stretch; gap: 6px; }
.mo-dau-nut .lien-ket-mui-ten { justify-content: center; }

/* ---------- Lớp học ---------- */
.ds-lop { margin-top: 24px; display: grid; grid-template-columns: minmax(0, 1fr); gap: 16px; }
.lop-the { padding: 20px; display: flex; flex-direction: column; gap: 12px; }
.lop-the-dau { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.lop-the h3 { font-size: 24px; }
.lop-the-ghi-chu { font-size: 16px; color: var(--mau-chu-phu); }
.thong-so { display: flex; align-items: center; gap: 12px; }
.thong-so-nhan { display: block; font-size: 13px; color: var(--mau-chu-phu); }
.thong-so-gia-tri { display: block; font-family: var(--font-tieu-de); font-weight: 800; font-size: 22px; line-height: 1.15; color: var(--mau-chinh); }
.ky-nang-nhan { font-size: 13px; color: var(--mau-chu-phu); }
.ds-chip { margin-top: 8px; display: flex; flex-wrap: wrap; gap: 8px; }
.chip { padding: 5px 14px; background: var(--mau-nen-phu); border: 1px solid var(--vien); color: var(--mau-chinh); border-radius: 999px; font-size: 14px; font-weight: 600; }
.ds-tich { display: flex; flex-direction: column; gap: 6px; font-size: 16px; }
.ds-tich li { display: flex; align-items: center; gap: 8px; }
.ds-tich .ic { width: 18px; height: 18px; stroke: var(--mau-chinh); stroke-width: 2.6; }
.lop-the .lien-ket-mui-ten { margin-top: auto; border-top: 1px solid var(--vien-nhat); padding-top: 8px; }

/* ---------- Lịch ---------- */
.lich-dau { display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between; gap: 8px 24px; }
.lich-cap-nhat { font-size: 14px; color: var(--mau-chu-phu); }
.ds-lich { margin-top: 20px; display: flex; flex-direction: column; gap: 12px; }
.lop { padding: 16px; background: var(--trang); border: 1px solid var(--vien); border-radius: 20px; display: grid; grid-template-columns: minmax(0, 1fr) auto; grid-template-areas: "ten khi" "gio gio"; align-items: center; gap: 10px 12px; }
.lop-ten { grid-area: ten; display: flex; flex-wrap: wrap; align-items: center; gap: 6px 10px; }
.lop-ten h3 { font-size: 22px; }
.lop-ten small { font-size: 13px; color: var(--mau-chu-phu); }
.lop-khi { grid-area: khi; display: flex; flex-direction: column; align-items: flex-end; gap: 6px; }
.lop-thang { font-family: var(--font-tieu-de); font-weight: 700; font-size: 17px; line-height: 1.1; color: var(--vang-dam); white-space: nowrap; }
.lop-gio { grid-area: gio; display: flex; flex-wrap: wrap; align-items: center; gap: 4px 10px; color: var(--mau-chinh); }
.lop-gio .ic { width: 18px; height: 18px; }
.lop-thu { font-size: 16px; color: var(--mau-chu-phu); }
.lop-khung-gio { font-weight: 600; font-size: 18px; color: var(--mau-chu); font-variant-numeric: tabular-nums; }
.lop--sap { background: var(--mau-chinh); border-color: var(--mau-chinh); color: var(--trang); }
.lop--sap h3, .lop--sap .lop-khung-gio, .lop--sap .lop-gio { color: var(--trang); }
.lop--sap .lop-thu { color: var(--hong-nhat); }
.lop--sap .lop-thang { color: var(--vang-kem); }
.lich-cuoi { margin-top: 16px; display: flex; flex-direction: column; gap: 16px; font-size: 14px; color: var(--mau-chu-phu); }

/* ---------- Cô giáo ---------- */
.co-giao .khung { display: grid; grid-template-columns: minmax(0, 1fr); grid-template-areas: "td" "anh" "ds"; gap: 20px; }
.co-giao-tieu-de { grid-area: td; }
.co-giao-anh { grid-area: anh; }
.co-giao .ds-thanh-tich { grid-area: ds; margin-top: 0; }
.khung-anh { padding: 14px 14px 0; background: var(--mau-nen); border: 1px solid var(--vien); border-radius: 24px; display: flex; justify-content: center; }
.khung-anh img { width: 100%; max-width: 190px; }
.co-giao-anh { max-width: 300px; width: 100%; justify-self: center; }
.bang-ten { position: relative; margin: -20px 16px 0; min-height: 52px; padding: 8px 16px; background: var(--mau-chinh); color: var(--trang); border-radius: 16px; display: flex; align-items: center; justify-content: center; text-align: center; font-family: var(--font-tieu-de); font-weight: 800; font-size: 22px; line-height: 1.15; }
.vai-tro { margin-top: 12px; text-align: center; font-size: 13px; font-weight: 600; letter-spacing: 1.6px; text-transform: uppercase; color: var(--vang-dam); }
.ds-thanh-tich { margin-top: 20px; display: flex; flex-direction: column; gap: 8px; }
.ds-thanh-tich li { min-height: 54px; padding: 8px 14px 8px 8px; background: var(--trang); border: 1px solid var(--vien); border-radius: 16px; display: flex; align-items: center; gap: 12px; font-size: 16px; font-weight: 500; line-height: 1.35; }

/* ---------- Điểm nổi bật ---------- */
.ds-noi-bat { margin-top: 20px; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.ds-noi-bat li { padding: 14px; background: var(--trang); border: 1px solid var(--vien); border-radius: 18px; display: flex; flex-direction: column; gap: 10px; font-size: 16px; font-weight: 600; line-height: 1.35; }

/* ---------- Cách học ---------- */
.ds-buoc { margin-top: 24px; display: grid; grid-template-columns: minmax(0, 1fr); gap: 20px; }
.ds-buoc li { display: flex; align-items: flex-start; gap: 14px; }
.so-buoc { width: 38px; height: 38px; flex-shrink: 0; border-radius: 50%; background: var(--mau-chinh); color: var(--trang); display: flex; align-items: center; justify-content: center; font-family: var(--font-tieu-de); font-weight: 800; font-size: 19px; line-height: 1; padding-top: 2px; }
.buoc-ten { display: block; font-weight: 600; font-size: 17px; line-height: 1.35; }
.buoc-mo-ta { display: block; margin-top: 4px; font-size: 16px; line-height: 1.5; color: var(--mau-chu-phu); }

/* ---------- Hỏi đáp ---------- */
.hoi-dap .khung { display: grid; grid-template-columns: minmax(0, 1fr); gap: 20px; }
.ds-hoi-dap { overflow: hidden; }
.ds-hoi-dap details + details { border-top: 1px solid var(--vien-nhat); }
.ds-hoi-dap summary { min-height: 58px; padding: 10px 16px; display: flex; align-items: center; justify-content: space-between; gap: 12px; font-weight: 600; line-height: 1.35; cursor: pointer; list-style: none; }
.ds-hoi-dap summary::-webkit-details-marker { display: none; }
.ds-hoi-dap summary .ic { stroke: var(--mau-chinh); stroke-width: 2.2; }
.ds-hoi-dap details[open] summary { color: var(--mau-chinh); }
.ds-hoi-dap details[open] summary .ic { transform: rotate(180deg); }
.ds-hoi-dap details p { padding: 0 16px 16px; max-width: 640px; font-size: 16px; color: var(--mau-chu-phu); }

/* ---------- Liên hệ ---------- */
.lien-he .khung { display: grid; grid-template-columns: minmax(0, 1fr); gap: 28px; }
.lien-he-nut { margin-top: 20px; display: flex; flex-direction: column; gap: 12px; }
.lien-he-so { font-variant-numeric: tabular-nums; }
.ma-qr { margin-top: 20px; padding: 20px; display: none; align-items: center; gap: 20px; background: var(--mau-nen); border: 1px solid var(--vien); border-radius: var(--bo-goc); }
.ma-qr img { width: 132px; height: 132px; border-radius: 12px; }
.ma-qr strong { display: block; font-size: 18px; }
.ma-qr span { display: block; margin-top: 4px; font-size: 16px; color: var(--mau-chu-phu); }
.hoac { display: flex; align-items: center; gap: 12px; font-size: 14px; color: var(--mau-chu-phu); }
.hoac::before, .hoac::after { content: ""; flex: 1 1 0; height: 1px; background: #E0CABD; }
.bieu-mau { margin-top: 20px; padding: 20px; background: var(--mau-nen); border: 1px solid var(--vien); border-radius: var(--bo-goc); display: flex; flex-direction: column; gap: 16px; }
.bieu-mau-dau { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.bieu-mau-dau h3 { font-size: 21px; line-height: 1.2; }
.bieu-mau-dau img { width: 86px; height: 88px; flex-shrink: 0; object-fit: cover; border-radius: 14px; }
.hang-truong { display: grid; grid-template-columns: minmax(0, 1fr); gap: 16px; }
.truong { display: flex; flex-direction: column; gap: 6px; }
.truong label, .bieu-mau legend { font-size: 14px; font-weight: 600; }
.truong input { width: 100%; height: 50px; padding: 0 14px; background: var(--trang); border: 1.5px solid var(--vien-o-nhap); border-radius: 14px; font-family: inherit; font-size: 16px; color: var(--mau-chu); }
.bieu-mau fieldset { border: 0; }
.bieu-mau legend { padding: 0; margin-bottom: 4px; }
.ds-lua-chon { display: grid; grid-template-columns: minmax(0, 1fr); gap: 0 24px; }
.ds-lua-chon label { min-height: 44px; display: flex; align-items: center; gap: 10px; font-size: 16px; font-weight: 400; cursor: pointer; }
.ds-lua-chon input { width: 20px; height: 20px; margin: 0; accent-color: var(--mau-chinh); }
.bieu-mau-ghi-chu { font-size: 14px; line-height: 1.5; color: var(--mau-chu-phu); }
.bieu-mau-ghi-chu a { font-weight: 600; }
.o-bay { position: absolute; left: -9999px; width: 1px; height: 1px; opacity: 0; }

/* ---------- Chân trang ---------- */
.chan-trang { background: var(--mau-chinh); color: var(--hong-nhat); padding: 36px 0 96px; }
.chan-trang .khung { display: flex; flex-direction: column; gap: 20px; }
.chan-trang-tren { display: flex; flex-direction: column; gap: 20px; }
.chan-trang .thuong-hieu { padding: 0; gap: 12px; }
.chan-trang .thuong-hieu img { width: 48px; height: 48px; border-radius: 10px; border: 1.5px solid var(--vang-kem); }
.chan-trang .thuong-hieu-ten { font-size: 19px; color: var(--trang); }
.chan-trang .thuong-hieu-han { font-size: 15px; color: var(--vang-kem); }
.khau-hieu { margin-top: 18px; font-family: var(--font-tieu-de); font-weight: 700; font-size: 21px; line-height: 1.2; color: var(--vang-kem); }
.ds-lien-he li { min-height: 44px; display: flex; align-items: center; gap: 12px; font-size: 16px; }
.ds-lien-he .ic { width: 18px; height: 18px; stroke: var(--vang-kem); }
.chan-trang a { color: var(--trang); font-weight: 600; text-decoration: none; }
.ds-lien-he a { min-height: 44px; display: inline-flex; align-items: center; }
.chan-trang a:hover { color: var(--vang-kem); }
.chan-trang-duong-ke { height: 1px; background: #A23A3D; }
.chan-trang-duoi { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 4px 24px; font-size: 14px; }
.chan-trang-duoi a { min-height: 44px; display: inline-flex; align-items: center; text-decoration: underline; }

/* ---------- Thanh nổi (chỉ điện thoại) ---------- */
.thanh-noi { position: fixed; left: 0; right: 0; bottom: 0; z-index: 30; display: none; gap: 10px; padding: 10px 16px calc(10px + env(safe-area-inset-bottom)); background: var(--trang); border-top: 1px solid var(--vien); }
.thanh-noi.hien { display: flex; }
.thanh-noi .nut { padding-left: 12px; padding-right: 12px; }
.thanh-noi .nut--vien { flex: 1 1 0; background: var(--trang); }
.thanh-noi .nut--chinh { flex: 2 1 0; }

/* ---------- Trang phụ (cảm ơn, chính sách) ---------- */
.trang-phu { padding: 40px 0 56px; }
.trang-phu .khung { max-width: 760px; }
.trang-phu h1 { margin-top: 0; font-size: 32px; }
.trang-phu h2 { margin-top: 32px; font-size: 22px; }
.trang-phu p, .trang-phu li { margin-top: 12px; }
.trang-phu ul { list-style: disc; padding-left: 22px; }
.trang-phu .ngay { font-size: 14px; color: var(--mau-chu-phu); }
.cam-on { text-align: center; }
.cam-on img { width: 150px; margin: 0 auto 20px; border-radius: 20px; }
.cam-on .lien-he-nut { max-width: 380px; margin-left: auto; margin-right: auto; }

/* ==========================================================
   Từ 720px: hai cột
   ========================================================== */
@media (min-width: 720px) {
  .ds-lop { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .ds-noi-bat { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
  .ds-noi-bat li { flex-direction: row; align-items: center; gap: 14px; padding: 16px; }
  .ds-buoc { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 28px 32px; }
  .lop { grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr) minmax(0, 1fr) auto; grid-template-areas: "ten thu gio khi"; padding: 18px 24px; gap: 12px 20px; }
  .lop-gio { display: contents; }
  .lop-gio .ic { display: none; }
  .lop-thu { grid-area: thu; font-size: 16px; }
  .lop-khung-gio { grid-area: gio; font-size: 20px; }
  .lop-khi { flex-direction: row; align-items: center; gap: 12px; }
  .lich-cuoi { flex-direction: row; align-items: center; justify-content: space-between; font-size: 16px; }
  .hang-truong { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .ds-lua-chon { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .co-giao .khung { grid-template-columns: minmax(0, 340px) minmax(0, 1fr); grid-template-areas: "anh td" "anh ds"; grid-template-rows: auto 1fr; gap: 20px 40px; }
  .co-giao-tieu-de { align-self: end; }
  .co-giao-anh { align-self: center; }
  .mo-dau-nut { flex-direction: row; flex-wrap: wrap; align-items: center; gap: 8px 24px; }
  .lien-he-nut { flex-direction: row; flex-wrap: wrap; }
  .chan-trang-tren { flex-direction: row; justify-content: space-between; gap: 32px 64px; }
}

/* ==========================================================
   Từ 1024px: bố cục máy tính
   ========================================================== */
@media (min-width: 1024px) {
  body { font-size: 17px; line-height: 1.6; }
  .khung { padding-left: 40px; padding-right: 40px; }
  section[id] { scroll-margin-top: 84px; }
  .khoi { padding: 72px 0; }
  .nhan-khoi { font-size: 14px; letter-spacing: 1.8px; }
  h2 { margin-top: 8px; font-size: 38px; }
  .mo-ta-khoi { font-size: 17px; }

  .dau-trang .khung { min-height: 76px; flex-wrap: nowrap; padding-right: 40px; }
  .thuong-hieu img { width: 48px; height: 48px; border-radius: 10px; }
  .thuong-hieu-ten { font-size: 21px; }
  .thuong-hieu-han { font-size: 15px; letter-spacing: 4px; }
  .js .nut-menu, .nut-menu { display: none; }
  .js .menu, .menu { width: auto; display: flex; flex-direction: row; align-items: center; gap: 28px; padding: 0; }
  .menu a { min-height: 44px; border-top: 0; font-size: 16px; }
  .menu .nut { display: inline-flex; min-height: 46px; color: var(--trang); }

  .mo-dau .khung { padding-top: 64px; padding-bottom: 72px; grid-template-columns: minmax(0, 1.25fr) minmax(0, 400px); grid-template-areas: "nhan co-giao" "tieu-de co-giao" "mo-ta co-giao" "nut co-giao" ". co-giao"; column-gap: 64px; align-items: start; }
  .mo-dau-nhan { min-height: 36px; padding: 0 16px; font-size: 14px; }
  h1 { margin-top: 20px; font-size: clamp(46px, 5vw, 62px); line-height: 1.06; letter-spacing: -0.5px; }
  .mo-dau-mo-ta { margin-top: 20px; max-width: 520px; font-size: 19px; }
  .mo-dau-nut { margin-top: 32px; }
  .mo-dau-nut .nut { min-height: 58px; padding: 10px 28px; font-size: 17px; }
  .mo-dau-co-giao { margin-top: 0; padding: 0; flex-direction: column; align-items: stretch; gap: 0; background: transparent; border: 0; border-radius: 0; }
  .mo-dau-co-giao img { width: 100%; height: auto; border-radius: 0; background: transparent; }
  .mo-dau-co-giao-chu { position: relative; margin: -22px 20px 0; padding: 14px 20px; gap: 2px; background: var(--mau-chinh); border-radius: 18px; text-align: center; font-size: 16px; color: var(--hong-nhat); }
  .mo-dau-co-giao-chu strong { font-weight: 800; font-size: 23px; color: var(--trang); }

  .ds-lop { margin-top: 32px; gap: 24px; }
  .lop-the { padding: 26px; gap: 14px; }
  .lop-the h3 { font-size: 28px; }
  .ds-lich { margin-top: 28px; }
  .lop { padding: 20px 28px; border-radius: 22px; }
  .lop-ten h3 { font-size: 26px; }
  .lop-khung-gio { font-size: 22px; }
  .lop-thang { font-size: 21px; }

  .co-giao .khung { grid-template-columns: minmax(0, 420px) minmax(0, 1fr); gap: 24px 64px; }
  .khung-anh { padding: 20px 20px 0; border-radius: 28px; }
  .khung-anh img { max-width: 360px; }
  .bang-ten { margin: -22px 24px 0; font-size: 25px; border-radius: 18px; }
  .ds-thanh-tich { gap: 10px; }
  .ds-thanh-tich li { min-height: 58px; padding: 8px 18px 8px 9px; border-radius: 18px; gap: 14px; font-size: 17px; }

  .ds-noi-bat { margin-top: 28px; }
  .ds-noi-bat li { min-height: 84px; padding: 18px 20px; gap: 16px; font-size: 17px; border-radius: 20px; }
  .ds-noi-bat .vong-bieu-tuong { width: 46px; height: 46px; }
  .ds-buoc { margin-top: 32px; grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .ds-buoc li { flex-direction: column; gap: 10px; }
  .so-buoc { width: 44px; height: 44px; font-size: 22px; }
  .buoc-ten { font-size: 19px; }
  .buoc-mo-ta { margin-top: 6px; font-size: 16px; }

  .hoi-dap .khung { grid-template-columns: minmax(0, 1fr) minmax(0, 2fr); gap: 64px; align-items: start; }
  .ds-hoi-dap summary { min-height: 64px; padding: 12px 24px; font-size: 18px; }
  .ds-hoi-dap details p { padding: 0 24px 20px; font-size: 16px; }

  .lien-he .khung { grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr); gap: 64px; align-items: start; }
  .lien-he .khung:has(#khoi-bieu-mau[hidden]) { grid-template-columns: minmax(0, 640px); }
  .ma-qr { display: flex; }
  .hoac { display: none; }
  .bieu-mau { margin-top: 0; padding: 28px; border-radius: 24px; gap: 18px; }
  .bieu-mau-dau h3 { font-size: 25px; }
  .bieu-mau-dau img { width: 96px; height: 99px; }
  .bieu-mau .nut { align-self: flex-start; padding-left: 32px; padding-right: 32px; }

  .chan-trang { padding: 56px 0 40px; }
  .chan-trang .khung { gap: 32px; }
  .chan-trang .thuong-hieu img { width: 56px; height: 56px; border-radius: 12px; }
  .chan-trang .thuong-hieu-ten { font-size: 23px; }
  .chan-trang .thuong-hieu-han { font-size: 17px; }
  .khau-hieu { font-size: 26px; }
  .ds-lien-he li { font-size: 16px; }
  .thanh-noi, .thanh-noi.hien { display: none; }
  .trang-phu { padding: 64px 0 80px; }
  .trang-phu h1 { font-size: 42px; }
}

/* ---------- Bổ sung v3: hợp với ai, con số, chọn lớp ---------- */
.ghi-chu-nut { font-size: 14px; color: var(--mau-chu-phu); text-align: center; }
.hop-voi-ai { padding-top: 12px; }
.ds-hop { margin-top: 20px; display: grid; grid-template-columns: minmax(0, 1fr); gap: 12px; }
.ds-hop li { padding: 14px 16px; background: var(--trang); border: 1px solid var(--vien); border-radius: 18px; display: flex; align-items: center; gap: 14px; font-weight: 500; line-height: 1.4; }
.ds-hop .ic { stroke-width: 2.6; }
.ds-con-so { margin-top: 16px; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.ds-con-so li { padding: 14px 16px; background: var(--trang); border: 1px solid var(--vien); border-radius: 18px; }
.ds-con-so strong { display: block; font-family: var(--font-tieu-de); font-weight: 800; font-size: 30px; line-height: 1.1; color: var(--mau-chinh); }
.ds-con-so span { display: block; margin-top: 2px; font-size: 14px; color: var(--mau-chu-phu); }
.chon-lop { margin-top: 20px; display: flex; flex-wrap: wrap; gap: 10px; }
.chon-lop-nut { min-height: 46px; padding: 6px 22px; display: inline-flex; align-items: center; border: 2px solid var(--mau-chinh); border-radius: 999px; background: var(--mau-nen); color: var(--mau-chinh); font-weight: 600; cursor: pointer; }
.chon-lop input:checked + .chon-lop-nut { background: var(--mau-chinh); color: var(--trang); }
.chon-lop input:focus-visible + .chon-lop-nut { outline: 3px solid var(--mau-chinh); outline-offset: 2px; }
.chon-lop .ds-noi-bat { display: none; flex: 1 1 100%; margin-top: 6px; }
#nb-so:checked ~ [data-lop="so"], #nb-trung:checked ~ [data-lop="trung"], #nb-nang:checked ~ [data-lop="nang"] { display: grid; }
@media (min-width: 720px) {
  .ds-hop { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
  .ghi-chu-nut { text-align: left; }
  .ds-con-so { max-width: 420px; }
}
@media (min-width: 1024px) {
  .hop-voi-ai { padding-top: 0; }
  .ds-hop { margin-top: 28px; }
  .ds-hop li { padding: 18px 20px; }
  .ds-con-so strong { font-size: 36px; }
  .ds-con-so span { font-size: 15px; }
  .chon-lop { margin-top: 28px; }
}

/* ---------- v4: ảnh cô giáo nhỏ hơn trên điện thoại, lớn dần theo màn hình ---------- */
@media (min-width: 720px) { .khung-anh img { max-width: 280px; } .co-giao-anh { max-width: none; } }
@media (min-width: 1024px) { .khung-anh img { max-width: 360px; } }