/* ============================================================
   TÂM NHÀ THẬT ACADEMY — Stylesheet
   Bảng màu: mực đen ấm + vàng đồng + kem
   ============================================================ */

:root {
  --muc: #14110f;
  --muc-2: #1e1a17;
  --muc-3: #2b2521;
  --vang: #d9a441;
  --vang-sang: #f0c463;
  --vang-mo: rgba(217, 164, 65, 0.12);
  --kem: #faf7f2;
  --kem-2: #f2ece2;
  --vien: #e4dbcd;
  --chu: #241f1b;
  --chu-nhat: #6d635a;
  --chu-tren-toi: #f5efe6;
  --chu-nhat-toi: #a89c8e;

  --ch-vang: #d9a441;
  --ch-xanh: #4b7f6d;
  --ch-do: #b5544a;
  --ch-tim: #6b5b8e;

  --bo-goc: 14px;
  --bo-goc-nho: 9px;
  --bong: 0 1px 2px rgba(20, 17, 15, 0.04), 0 8px 24px rgba(20, 17, 15, 0.06);
  --bong-noi: 0 4px 12px rgba(20, 17, 15, 0.08), 0 20px 48px rgba(20, 17, 15, 0.12);
  --rong: 1180px;
  --muot: 0.22s cubic-bezier(0.4, 0, 0.2, 1);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: "Be Vietnam Pro", -apple-system, BlinkMacSystemFont, "Segoe UI",
    "Helvetica Neue", Arial, sans-serif;
  background: var(--kem);
  color: var(--chu);
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; border: none; background: none; }

.boc {
  width: 100%;
  max-width: var(--rong);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Thanh điều hướng ---------- */

.thanh-dieu-huong {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 247, 242, 0.88);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--vien);
}

.thanh-dieu-huong.toi {
  background: rgba(20, 17, 15, 0.9);
  border-bottom-color: rgba(255, 255, 255, 0.08);
  color: var(--chu-tren-toi);
}

.dh-trong {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  gap: 20px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 11px;
  font-weight: 700;
  font-size: 17px;
  letter-spacing: -0.01em;
  flex-shrink: 0;
}

.logo-dau {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--vang-sang), var(--vang));
  display: grid;
  place-items: center;
  font-size: 15px;
  font-weight: 800;
  color: var(--muc);
  letter-spacing: -0.02em;
}

.logo-phu {
  display: block;
  font-size: 10.5px;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--chu-nhat);
  margin-top: -2px;
}

.toi .logo-phu { color: var(--chu-nhat-toi); }

.dh-lien-ket {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
}

.dh-lien-ket a {
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 14.5px;
  font-weight: 500;
  color: var(--chu-nhat);
  transition: var(--muot);
}

.dh-lien-ket a:hover { color: var(--chu); background: var(--kem-2); }
.dh-lien-ket a.dang-o { color: var(--chu); font-weight: 600; }
.toi .dh-lien-ket a { color: var(--chu-nhat-toi); }
.toi .dh-lien-ket a:hover { color: #fff; background: rgba(255, 255, 255, 0.07); }

.nut {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 14.5px;
  transition: var(--muot);
  white-space: nowrap;
}

.nut-chinh {
  background: var(--muc);
  color: var(--kem);
}
.nut-chinh:hover { background: var(--muc-3); transform: translateY(-1px); }

.nut-vang {
  background: linear-gradient(135deg, var(--vang-sang), var(--vang));
  color: var(--muc);
}
.nut-vang:hover { filter: brightness(1.06); transform: translateY(-1px); }

.nut-vien {
  border: 1.5px solid var(--vien);
  color: var(--chu);
  background: transparent;
}
.nut-vien:hover { border-color: var(--muc); }

.toi .nut-vien { border-color: rgba(255, 255, 255, 0.22); color: var(--chu-tren-toi); }
.toi .nut-vien:hover { border-color: var(--vang); color: var(--vang-sang); }

.nut-menu { display: none; font-size: 22px; padding: 6px 10px; }

.nut-nho { padding: 8px 15px; font-size: 13.5px; border-radius: 9px; }

/* ---------- Khu tài khoản ---------- */

#khuTaiKhoan {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.tk-da-vao {
  display: flex;
  align-items: center;
  gap: 10px;
}

.tk-ten {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 14px;
  font-weight: 600;
  color: var(--chu);
  max-width: 190px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.tk-ten svg { color: var(--vang); flex-shrink: 0; }

/* ---------- Băng báo xem thử ---------- */

.bang-xem-thu {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  background: #2b2521;
  color: var(--vang-sang);
  font-size: 13.5px;
  padding: 10px 20px;
  text-align: center;
  line-height: 1.5;
}

.bang-xem-thu svg { flex-shrink: 0; }
.bang-xem-thu b { color: #fff; }

/* ---------- Trạng thái bị khóa ---------- */

.the-bai.bi-khoa .the-anh img { filter: grayscale(0.55) brightness(0.72); }
.the-bai.bi-khoa .the-play { opacity: 1; background: rgba(20, 17, 15, 0.42); }
.the-bai.bi-khoa .the-play span { background: rgba(250, 247, 242, 0.92); }
.the-bai.bi-khoa:hover .the-xem { color: var(--vang); }

.the-nhan-khoa {
  position: absolute;
  left: 10px;
  top: 10px;
  display: inline-flex;
  align-items: center;
  gap: 5px;
  background: rgba(20, 17, 15, 0.86);
  color: var(--vang-sang);
  font-size: 11px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 5px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.cb-bai.bi-khoa .cb-noi-dung strong { color: var(--chu-nhat); }
.cb-bai.bi-khoa .cb-noi-dung span svg { color: var(--vang); }

/* ---------- Màn hình khóa trên trang bài học ---------- */

.man-khoa { background: linear-gradient(160deg, #241f1b, var(--muc)); }

.man-khoa .khoa-vong {
  display: grid;
  place-items: center;
  width: 62px;
  height: 62px;
  margin: 0 auto 18px;
  border-radius: 50%;
  background: var(--vang-mo);
  border: 1px solid rgba(217, 164, 65, 0.3);
  color: var(--vang);
}

.man-khoa strong { font-size: 19px; margin-bottom: 10px; }
.man-khoa > div > span { display: block; max-width: 400px; margin: 0 auto; font-size: 14.5px; }

.khoa-nut {
  display: flex;
  gap: 10px;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 22px;
}

/* ---------- Hero ---------- */

.hero {
  background: var(--muc);
  color: var(--chu-tren-toi);
  padding: 92px 0 100px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(720px 420px at 78% 12%, rgba(217, 164, 65, 0.17), transparent 62%),
    radial-gradient(560px 380px at 8% 88%, rgba(217, 164, 65, 0.07), transparent 60%);
  pointer-events: none;
}

.hero-trong { position: relative; max-width: 780px; }

.the-nho {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: 999px;
  background: var(--vang-mo);
  border: 1px solid rgba(217, 164, 65, 0.28);
  color: var(--vang-sang);
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  margin-bottom: 26px;
}

.the-nho::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--vang);
}

.hero h1 {
  font-size: clamp(34px, 5.2vw, 56px);
  line-height: 1.12;
  font-weight: 800;
  letter-spacing: -0.028em;
  margin-bottom: 22px;
}

.hero h1 em {
  font-style: normal;
  color: var(--vang);
  position: relative;
  white-space: nowrap;
}

.hero p.dan {
  font-size: clamp(16px, 1.9vw, 19px);
  color: var(--chu-nhat-toi);
  max-width: 640px;
  margin-bottom: 34px;
}

.hero-nut { display: flex; gap: 12px; flex-wrap: wrap; }

.hero-so {
  display: flex;
  gap: 44px;
  margin-top: 60px;
  padding-top: 34px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  flex-wrap: wrap;
}

.hero-so div strong {
  display: block;
  font-size: 28px;
  font-weight: 800;
  color: var(--vang);
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.hero-so div span {
  font-size: 13.5px;
  color: var(--chu-nhat-toi);
}

/* ---------- Dải cam kết ---------- */

.dai-cam-ket {
  background: var(--muc-2);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding: 26px 0;
}

.dai-trong {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 24px;
}

.dai-muc {
  display: flex;
  gap: 13px;
  align-items: flex-start;
  color: var(--chu-nhat-toi);
  font-size: 14.5px;
}

.dai-muc svg { flex-shrink: 0; margin-top: 3px; color: var(--vang); }
.dai-muc strong { display: block; color: var(--chu-tren-toi); font-weight: 600; font-size: 15px; }

/* ---------- Khối chung ---------- */

.khoi { padding: 76px 0; }
.khoi-kem { background: var(--kem-2); }

.dau-khoi { margin-bottom: 40px; max-width: 660px; }

.nhan-khoi {
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--vang);
  margin-bottom: 12px;
}

.dau-khoi h2 {
  font-size: clamp(26px, 3.4vw, 36px);
  font-weight: 800;
  letter-spacing: -0.025em;
  line-height: 1.2;
  margin-bottom: 12px;
}

.dau-khoi p { color: var(--chu-nhat); font-size: 16.5px; }

/* ---------- Bộ lọc ---------- */

.bo-loc {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 32px;
  align-items: center;
}

.chip {
  padding: 9px 17px;
  border-radius: 999px;
  border: 1.5px solid var(--vien);
  background: #fff;
  font-size: 14px;
  font-weight: 500;
  color: var(--chu-nhat);
  transition: var(--muot);
}

.chip:hover { border-color: var(--chu-nhat); color: var(--chu); }

.chip.chon {
  background: var(--muc);
  border-color: var(--muc);
  color: var(--kem);
  font-weight: 600;
}

.o-tim {
  margin-left: auto;
  position: relative;
  min-width: 250px;
}

.o-tim input {
  width: 100%;
  padding: 10px 15px 10px 40px;
  border-radius: 999px;
  border: 1.5px solid var(--vien);
  background: #fff;
  font-size: 14.5px;
  font-family: inherit;
  color: var(--chu);
  transition: var(--muot);
}

.o-tim input:focus { outline: none; border-color: var(--vang); box-shadow: 0 0 0 3px var(--vang-mo); }
.o-tim svg { position: absolute; left: 14px; top: 50%; transform: translateY(-50%); color: var(--chu-nhat); }

/* ---------- Chương ---------- */

.chuong { margin-bottom: 52px; }

.chuong-dau {
  display: flex;
  align-items: flex-start;
  gap: 15px;
  margin-bottom: 22px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--vien);
}

.chuong-vach {
  width: 4px;
  align-self: stretch;
  border-radius: 3px;
  background: var(--ch-vang);
  flex-shrink: 0;
  min-height: 46px;
}

.chuong[data-mau="xanh"] .chuong-vach { background: var(--ch-xanh); }
.chuong[data-mau="do"] .chuong-vach { background: var(--ch-do); }
.chuong[data-mau="tim"] .chuong-vach { background: var(--ch-tim); }

.chuong-dau h3 {
  font-size: 21px;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 4px;
}

.chuong-dau p { color: var(--chu-nhat); font-size: 15px; max-width: 620px; }

.chuong-dem {
  margin-left: auto;
  flex-shrink: 0;
  font-size: 13px;
  color: var(--chu-nhat);
  background: #fff;
  border: 1px solid var(--vien);
  padding: 5px 13px;
  border-radius: 999px;
  white-space: nowrap;
}

/* ---------- Thẻ bài học ---------- */

.luoi-bai {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(288px, 1fr));
  gap: 22px;
}

.the-bai {
  background: #fff;
  border: 1px solid var(--vien);
  border-radius: var(--bo-goc);
  overflow: hidden;
  transition: var(--muot);
  display: flex;
  flex-direction: column;
}

.the-bai:hover {
  transform: translateY(-3px);
  box-shadow: var(--bong-noi);
  border-color: transparent;
}

.the-anh {
  position: relative;
  aspect-ratio: 16 / 9;
  background: linear-gradient(145deg, var(--muc-3), var(--muc));
  overflow: hidden;
}

.the-anh img { width: 100%; height: 100%; object-fit: cover; }

.the-anh-trong {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  color: rgba(217, 164, 65, 0.45);
}

.the-play {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  background: linear-gradient(to top, rgba(20, 17, 15, 0.5), rgba(20, 17, 15, 0.05));
  opacity: 0;
  transition: var(--muot);
}

.the-bai:hover .the-play { opacity: 1; }

.the-play span {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: rgba(250, 247, 242, 0.95);
  display: grid;
  place-items: center;
  color: var(--muc);
  padding-left: 3px;
}

.the-thoi-luong {
  position: absolute;
  right: 10px;
  bottom: 10px;
  background: rgba(20, 17, 15, 0.82);
  color: #fff;
  font-size: 12px;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 5px;
  letter-spacing: 0.02em;
}

.the-nhan-mp {
  position: absolute;
  left: 10px;
  top: 10px;
  background: var(--vang);
  color: var(--muc);
  font-size: 11px;
  font-weight: 800;
  padding: 4px 10px;
  border-radius: 5px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.the-than { padding: 17px 18px 19px; flex: 1; display: flex; flex-direction: column; }

.the-than h4 {
  font-size: 16.5px;
  font-weight: 700;
  line-height: 1.38;
  letter-spacing: -0.015em;
  margin-bottom: 8px;
}

.the-than p {
  font-size: 14px;
  color: var(--chu-nhat);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: 14px;
  flex: 1;
}

.the-chan {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  font-size: 13px;
  color: var(--chu-nhat);
  padding-top: 13px;
  border-top: 1px solid var(--kem-2);
}

.the-xem { color: var(--chu); font-weight: 600; display: inline-flex; align-items: center; gap: 5px; }
.the-bai:hover .the-xem { color: var(--vang); }

.da-xem {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  color: var(--ch-xanh);
  font-weight: 600;
}

/* ---------- Trang bài học ---------- */

.bo-hoc {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 356px;
  gap: 36px;
  padding: 32px 0 80px;
  align-items: start;
}

.khung-video {
  position: relative;
  aspect-ratio: 16 / 9;
  background: var(--muc);
  border-radius: var(--bo-goc);
  overflow: hidden;
  box-shadow: var(--bong-noi);
}

.khung-video iframe { width: 100%; height: 100%; border: 0; display: block; }

.video-cho {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 30px;
  color: var(--chu-nhat-toi);
}

.video-cho div { max-width: 400px; }
.video-cho svg { color: var(--vang); margin: 0 auto 16px; }
.video-cho strong { display: block; color: var(--chu-tren-toi); font-size: 17px; margin-bottom: 8px; }
.video-cho code {
  display: inline-block;
  margin-top: 12px;
  background: rgba(255, 255, 255, 0.08);
  padding: 6px 12px;
  border-radius: 7px;
  font-size: 13px;
  color: var(--vang-sang);
}

.duong-dan {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13.5px;
  color: var(--chu-nhat);
  padding: 22px 0 18px;
  flex-wrap: wrap;
}

.duong-dan a:hover { color: var(--vang); }

.bai-tieu-de {
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 800;
  letter-spacing: -0.025em;
  line-height: 1.22;
  margin: 22px 0 14px;
}

.bai-meta {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
  align-items: center;
  font-size: 14px;
  color: var(--chu-nhat);
  padding-bottom: 22px;
  border-bottom: 1px solid var(--vien);
  margin-bottom: 24px;
}

.bai-meta span { display: inline-flex; align-items: center; gap: 6px; }

.bai-mo-ta { font-size: 16.5px; color: #3a332d; margin-bottom: 30px; }

.hop-noi-dung {
  background: #fff;
  border: 1px solid var(--vien);
  border-radius: var(--bo-goc);
  padding: 24px 26px;
  margin-bottom: 26px;
}

.hop-noi-dung h3 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 9px;
}

.hop-noi-dung h3 svg { color: var(--vang); }

.hop-noi-dung ul { list-style: none; display: grid; gap: 11px; }

.hop-noi-dung li {
  display: flex;
  gap: 11px;
  font-size: 15.5px;
  color: #3a332d;
}

.hop-noi-dung li::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--vang);
  flex-shrink: 0;
  margin-top: 9px;
}

.hang-nut { display: flex; gap: 11px; flex-wrap: wrap; margin-bottom: 34px; }

.dieu-huong-bai {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.dh-the {
  border: 1px solid var(--vien);
  background: #fff;
  border-radius: var(--bo-goc);
  padding: 16px 18px;
  transition: var(--muot);
}

.dh-the:hover { border-color: var(--vang); box-shadow: var(--bong); }
.dh-the span { font-size: 12.5px; color: var(--chu-nhat); display: block; margin-bottom: 4px; }
.dh-the strong { font-size: 15px; font-weight: 600; line-height: 1.4; display: block; }
.dh-the.phai { text-align: right; }
.dh-the.trong { visibility: hidden; }

/* ---------- Sidebar danh sách bài ---------- */

.canh-ben {
  background: #fff;
  border: 1px solid var(--vien);
  border-radius: var(--bo-goc);
  overflow: hidden;
  position: sticky;
  top: 88px;
  max-height: calc(100vh - 112px);
  display: flex;
  flex-direction: column;
}

.cb-dau {
  padding: 18px 20px;
  border-bottom: 1px solid var(--vien);
  background: var(--kem);
}

.cb-dau strong { display: block; font-size: 15.5px; font-weight: 700; margin-bottom: 10px; }

.thanh-tien-do {
  height: 6px;
  border-radius: 4px;
  background: var(--kem-2);
  overflow: hidden;
  margin-bottom: 7px;
}

.thanh-tien-do i {
  display: block;
  height: 100%;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--vang), var(--vang-sang));
  transition: width 0.4s ease;
}

.cb-dau small { font-size: 12.5px; color: var(--chu-nhat); }

.cb-than { overflow-y: auto; flex: 1; }

.cb-chuong {
  padding: 13px 20px 7px;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--chu-nhat);
  background: var(--kem);
  border-top: 1px solid var(--vien);
}

.cb-bai {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  padding: 12px 20px;
  border-bottom: 1px solid var(--kem-2);
  transition: var(--muot);
}

.cb-bai:hover { background: var(--kem); }
.cb-bai.dang-hoc { background: var(--vang-mo); box-shadow: inset 3px 0 0 var(--vang); }

.cb-so {
  width: 25px; height: 25px;
  border-radius: 50%;
  background: var(--kem-2);
  display: grid;
  place-items: center;
  font-size: 12px;
  font-weight: 700;
  color: var(--chu-nhat);
  flex-shrink: 0;
  margin-top: 1px;
}

.cb-bai.dang-hoc .cb-so { background: var(--vang); color: var(--muc); }
.cb-bai.xong .cb-so { background: var(--ch-xanh); color: #fff; }

.cb-noi-dung { flex: 1; min-width: 0; }
.cb-noi-dung strong { display: block; font-size: 14px; font-weight: 600; line-height: 1.42; margin-bottom: 3px; }
.cb-bai.dang-hoc .cb-noi-dung strong { color: var(--muc); }
.cb-noi-dung span { font-size: 12.5px; color: var(--chu-nhat); display: inline-flex; align-items: center; gap: 5px; }

.cb-mp { color: var(--vang); font-weight: 700; }

/* ---------- CTA ---------- */

.cta {
  background: var(--muc);
  color: var(--chu-tren-toi);
  border-radius: 20px;
  padding: 54px 48px;
  position: relative;
  overflow: hidden;
  text-align: center;
}

.cta::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(620px 300px at 50% -10%, rgba(217, 164, 65, 0.2), transparent 65%);
}

.cta > * { position: relative; }
.cta h2 { font-size: clamp(24px, 3.2vw, 34px); font-weight: 800; letter-spacing: -0.025em; margin-bottom: 14px; }
.cta p { color: var(--chu-nhat-toi); max-width: 540px; margin: 0 auto 28px; font-size: 16.5px; }
.cta .hang-nut { justify-content: center; margin-bottom: 0; }

/* ---------- Chân trang ---------- */

.chan-trang {
  background: var(--muc);
  color: var(--chu-nhat-toi);
  padding: 56px 0 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.07);
}

.ct-luoi {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 36px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.ct-luoi p { font-size: 14.5px; max-width: 340px; margin-top: 14px; }
.ct-luoi h5 { color: var(--chu-tren-toi); font-size: 14px; font-weight: 700; margin-bottom: 13px; }
.ct-luoi ul { list-style: none; display: grid; gap: 9px; }
.ct-luoi ul a { font-size: 14.5px; transition: var(--muot); }
.ct-luoi ul a:hover { color: var(--vang); }
.ct-luoi .logo { color: var(--chu-tren-toi); }

.ct-cuoi {
  padding-top: 22px;
  font-size: 13px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

/* ---------- Rỗng ---------- */

.rong {
  text-align: center;
  padding: 70px 20px;
  color: var(--chu-nhat);
}

.rong svg { margin: 0 auto 16px; color: var(--vien); }
.rong strong { display: block; color: var(--chu); font-size: 18px; margin-bottom: 7px; }

/* ---------- Responsive ---------- */

@media (max-width: 1000px) {
  .bo-hoc { grid-template-columns: 1fr; }
  .canh-ben { position: static; max-height: none; }
  .ct-luoi { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 720px) {
  .boc { padding: 0 18px; }
  .hero { padding: 64px 0 68px; }
  .khoi { padding: 54px 0; }
  .nut-menu { display: block; }

  .dh-lien-ket {
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    background: var(--kem);
    border-bottom: 1px solid var(--vien);
    padding: 10px 18px 16px;
    display: none;
    margin-left: 0;
  }

  .dh-lien-ket.mo { display: flex; }
  .dh-lien-ket a { padding: 11px 12px; }
  .thanh-dieu-huong.toi .dh-lien-ket { background: var(--muc-2); }

  .dh-nut-phai { display: none; }
  .tk-ten { max-width: 96px; }
  .nut-nho { padding: 7px 12px; font-size: 13px; }
  .bang-xem-thu { font-size: 12.5px; text-align: left; }
  .man-khoa .khoa-vong { width: 52px; height: 52px; margin-bottom: 14px; }
  .man-khoa strong { font-size: 16.5px; }
  .man-khoa > div > span { font-size: 13.5px; }
  .khoa-nut .nut { width: 100%; }
  .hero-so { gap: 28px; margin-top: 42px; }
  .hero-so div strong { font-size: 23px; }
  .o-tim { margin-left: 0; width: 100%; }
  .chuong-dem { display: none; }
  .luoi-bai { grid-template-columns: 1fr; }
  .cta { padding: 40px 24px; border-radius: 16px; }
  .ct-luoi { grid-template-columns: 1fr; gap: 30px; }
  .dieu-huong-bai { grid-template-columns: 1fr; }
  .dh-the.phai { text-align: left; }
  .dh-the.trong { display: none; }
  .hop-noi-dung { padding: 20px; }
}