/* =========================================================================
   Silver House — Bảo tàng hiện vật
   Dùng cho ba trang: /bao-tang/, /bao-tang/khu/<slug>/ và
   /bao-tang/hien-vat/<slug>/.

   Tông màu bám theo bộ CSS lõi: giấy #f5ede2, nâu chữ #3d2b20, nâu nhấn #8e6444
   và mận đậm #5a1f26 cho các con số trên sơ đồ.
   ========================================================================= */

.rt3-museum-page {
  --bt-giay:   #f7f0e6;
  --bt-giay-2: #efe4d5;
  --bt-nau:    #3d2b20;
  --bt-nau-2:  #6d5947;
  --bt-nau-3:  #96806a;
  --bt-nhan:   #8e6444;
  --bt-man:    #5a1f26;
  --bt-vien:   rgba(142, 100, 68, 0.2);
}

/* -------------------------------------------------------------------- Hero
   Ảnh tràn mép trái, nội dung bên phải. Dưới 980px xếp dọc, ảnh lên trước. */

.bt-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
  align-items: center;
  gap: 0 64px;
  padding: 0 56px 0 0;
  background: var(--bt-giay);
}

.bt-hero-anh {
  position: relative;
  overflow: hidden;
  min-height: 520px;
  height: 100%;
  background: #d7c5af;
}

.bt-hero-anh img {
  display: block;
  width: 100%;
  height: 100%;
  min-height: 520px;
  object-fit: cover;
}

.bt-hero-noi-dung { padding: 72px 0; max-width: 620px; }

.bt-hero-noi-dung .rt3-crumb { margin-bottom: 26px; }

.bt-hero-noi-dung h1 {
  margin: 10px 0 22px;
  font-family: "Playfair Display", Georgia, serif;
  font-size: clamp(34px, 4vw, 52px);
  font-weight: 400;
  line-height: 1.16;
  color: var(--bt-nau);
}

.bt-lead {
  margin: 0;
  max-width: 54ch;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--bt-nau-2);
}

.bt-hero-so {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 40px;
  margin-top: 38px;
  padding-top: 30px;
  border-top: 1px solid var(--bt-vien);
}

.bt-hero-so > div { min-width: 130px; }

.bt-hero-so .bt-i {
  display: block;
  width: 26px;
  height: 26px;
  margin-bottom: 10px;
  color: var(--bt-nhan);
}

.bt-hero-so b {
  display: block;
  font-family: "Playfair Display", Georgia, serif;
  font-size: 25px;
  font-weight: 500;
  line-height: 1.2;
  color: var(--bt-nau);
}

.bt-hero-so span {
  display: block;
  margin-top: 4px;
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--bt-nau-3);
}

/* Trang khu trưng bày: ảnh hero cao hơn một chút cho cân với hai cột chữ. */
.bt-hero-khu .bt-hero-anh,
.bt-hero-khu .bt-hero-anh img { min-height: 560px; }

/* ------------------------------------------------------------ Tiêu đề khối */

.bt-tieu-de { margin-bottom: 44px; text-align: center; }

.bt-tieu-de h2 {
  margin: 8px 0 0;
  font-family: "Playfair Display", Georgia, serif;
  font-size: clamp(26px, 3vw, 36px);
  font-weight: 400;
  line-height: 1.25;
  color: var(--bt-nau);
  white-space: pre-line;
}

.bt-gioi-thieu {
  max-width: 76ch;
  margin: 0 auto;
  text-align: center;
}

.bt-gioi-thieu p {
  margin: 0 0 14px;
  font-size: 15.5px;
  line-height: 1.82;
  color: var(--bt-nau-2);
}

/* ------------------------------------------------------------ Lưới hiện vật */

.bt-hv-luoi {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 26px;
}

.bt-hv-luoi-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.bt-hv[hidden] { display: none; }

.bt-hv {
  display: flex;
  flex-direction: column;
  animation: btHien 640ms cubic-bezier(0.2, 0.72, 0.2, 1) calc(var(--i, 0) * 80ms) 1 both;
}

.bt-hv-anh {
  display: block;
  overflow: hidden;
  border-radius: 1rem;
  background: #d7c5af;
}

.bt-hv-anh img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  transition: transform 800ms cubic-bezier(0.2, 0.72, 0.2, 1);
}

.bt-hv:hover .bt-hv-anh img { transform: scale(1.05); }

.bt-hv h3 {
  margin: 16px 0 6px;
  font-family: "Playfair Display", Georgia, serif;
  font-size: 17px;
  font-weight: 500;
  line-height: 1.35;
}

.bt-hv h3 a { color: var(--bt-nau); text-decoration: none; }
.bt-hv h3 a:hover { color: var(--bt-nhan); }

.bt-hv small {
  display: block;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--bt-nau-3);
}

.bt-hv .bt-kham-pha { margin: 12px 0 0; }

.bt-loc { margin-bottom: 34px; }

/* ------------------------------------------------ Các khu khác (thẻ nhỏ) */

.bt-khu-nho {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 20px;
}

.bt-khu-nho a {
  display: block;
  padding-bottom: 18px;
  border: 1px solid var(--bt-vien);
  border-radius: 1rem;
  background: rgba(255, 255, 255, 0.5);
  color: inherit;
  text-decoration: none;
  overflow: hidden;
  transition: border-color 240ms ease, transform 240ms ease;
}

.bt-khu-nho a:hover { border-color: var(--bt-nhan); transform: translateY(-3px); }

.bt-khu-nho img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 7 / 5;
  object-fit: cover;
  background: #d7c5af;
}

.bt-khu-nho b {
  display: block;
  margin: 14px 16px 5px;
  font-family: "Playfair Display", Georgia, serif;
  font-size: 15px;
  font-weight: 500;
  color: var(--bt-nau);
}

.bt-khu-nho small {
  display: block;
  margin: 0 16px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--bt-nau-2);
}

.bt-khu-nho-so-do img { object-fit: contain; background: #fdf8f0; padding: 8px; }

/* ------------------------------------------------- Chi tiết một hiện vật */

.bt-hv-dau { padding-top: 40px; }

.bt-hv-dau .rt3-crumb { margin-bottom: 30px; }

.bt-hv-chi-tiet {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
  align-items: start;
  gap: 56px;
}

.bt-hv-anh-lon {
  margin: 0;
  overflow: hidden;
  border-radius: 1.2rem;
  background: #d7c5af;
}

.bt-hv-anh-lon img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.bt-hv-thumbs {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
  margin-top: 12px;
}

.bt-hv-thumbs button {
  padding: 0;
  border: 2px solid transparent;
  border-radius: 0.6rem;
  background: none;
  cursor: pointer;
  overflow: hidden;
  transition: border-color 220ms ease, opacity 220ms ease;
  opacity: 0.72;
}

.bt-hv-thumbs button:hover { opacity: 1; }

.bt-hv-thumbs button.is-active {
  border-color: var(--bt-nhan);
  opacity: 1;
}

.bt-hv-thumbs img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.bt-hv-info h1 {
  margin: 10px 0 14px;
  font-family: "Playfair Display", Georgia, serif;
  font-size: clamp(30px, 3.4vw, 44px);
  font-weight: 400;
  line-height: 1.16;
  color: var(--bt-nau);
}

.bt-hv-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin: 0 0 26px;
  padding-bottom: 22px;
  border-bottom: 1px solid var(--bt-vien);
  font-size: 13.5px;
  color: var(--bt-nau-2);
}

.bt-hv-meta span { position: relative; }

.bt-hv-meta span + span::before {
  content: "•";
  position: absolute;
  left: -12px;
  color: var(--bt-nau-3);
}

.bt-hv-bang { margin: 0 0 26px; }

.bt-hv-bang > div {
  display: grid;
  grid-template-columns: 148px minmax(0, 1fr);
  gap: 16px;
  padding: 11px 0;
  border-bottom: 1px solid rgba(142, 100, 68, 0.12);
}

.bt-hv-bang dt {
  margin: 0;
  font-size: 13px;
  color: var(--bt-nau-3);
}

.bt-hv-bang dd {
  margin: 0;
  font-size: 14px;
  line-height: 1.55;
  color: var(--bt-nau);
}

.bt-hv-vitri {
  margin: 0 0 24px;
  padding: 16px 20px;
  border: 1px solid var(--bt-vien);
  border-radius: 0.9rem;
  background: rgba(255, 255, 255, 0.55);
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--bt-nau-2);
}

.bt-hv-vitri a { display: block; margin-top: 4px; color: var(--bt-nhan); }

.bt-hv-nut { display: flex; flex-direction: column; gap: 10px; }
.bt-hv-nut .rt3-btn { justify-content: center; text-align: center; }

/* ---------------------------------------------------- Câu chuyện hiện vật */

.bt-cau-chuyen {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
  align-items: center;
  gap: 56px;
}

.bt-cau-chuyen-copy h2 {
  margin: 8px 0 18px;
  font-family: "Playfair Display", Georgia, serif;
  font-size: clamp(22px, 2.4vw, 30px);
  font-weight: 400;
  line-height: 1.3;
  color: var(--bt-nau);
}

.bt-cau-chuyen-copy p {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--bt-nau-2);
}

.bt-cau-chuyen-anh {
  margin: 0;
  overflow: hidden;
  border-radius: 1.2rem;
  background: #d7c5af;
}

.bt-cau-chuyen-anh img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

/* -------------------------------------------------------- Hiện vật liên quan */

.bt-lien-quan {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.bt-lien-quan a {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  align-items: center;
  gap: 14px;
  padding: 12px 16px 12px 12px;
  border: 1px solid var(--bt-vien);
  border-radius: 1rem;
  background: rgba(255, 255, 255, 0.55);
  color: inherit;
  text-decoration: none;
  transition: border-color 240ms ease, transform 240ms ease;
}

.bt-lien-quan a:hover { border-color: var(--bt-nhan); transform: translateY(-3px); }

.bt-lien-quan img {
  width: 92px;
  height: 70px;
  border-radius: 0.6rem;
  object-fit: cover;
  background: #d7c5af;
}

.bt-lien-quan b {
  display: block;
  margin-bottom: 3px;
  font-family: "Playfair Display", Georgia, serif;
  font-size: 14.5px;
  font-weight: 500;
  line-height: 1.34;
  color: var(--bt-nau);
}

.bt-lien-quan small { display: block; font-size: 12px; color: var(--bt-nau-3); }

.bt-lien-quan span {
  display: block;
  margin-top: 6px;
  font-size: 10.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--bt-nhan);
}

.bt-cta-gio { margin-top: 10px; font-size: 13px; opacity: 0.8; }

/* ------------------------------------------------------------ Màn hình nhỏ */

@media (max-width: 1180px) {
  .bt-hv-luoi,
  .bt-khu-nho { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .bt-lien-quan { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 980px) {
  .bt-hero {
    grid-template-columns: minmax(0, 1fr);
    gap: 0;
    padding: 0;
  }

  .bt-hero-anh,
  .bt-hero-anh img,
  .bt-hero-khu .bt-hero-anh,
  .bt-hero-khu .bt-hero-anh img { min-height: 320px; }

  .bt-hero-noi-dung { padding: 40px 24px 56px; max-width: none; }

  .bt-hv-chi-tiet,
  .bt-cau-chuyen { grid-template-columns: minmax(0, 1fr); gap: 36px; }

  .bt-hv-luoi-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 680px) {
  .bt-hv-luoi,
  .bt-hv-luoi-3,
  .bt-khu-nho,
  .bt-lien-quan { grid-template-columns: minmax(0, 1fr); }

  .bt-hv-bang > div { grid-template-columns: minmax(0, 1fr); gap: 2px; }
  .bt-hv-thumbs { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .bt-tieu-de { text-align: left; }
  .bt-gioi-thieu { text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
  .bt-hv { animation: none; }
  .bt-hv-anh img { transition: none; }
}

/* =========================================================================
   Mặt trước bảo tàng — /bao-tang/
   Dựng theo mockup khách duyệt 23/08/2026. Tiền tố .btm- riêng cho trang này,
   không đụng .bt-* mà trang khu trưng bày và trang hiện vật dùng chung.
   ========================================================================= */

.rt3-museum-page {
  --btm-vang:  #d8c7a4;   /* số thứ tự lớn */
  --btm-vien2: #e3d8c5;
}

/* ------------------------------------------------------------------- Hero
   Ảnh tràn hết chiều ngang, khối chữ đặt trên một lớp giấy mờ dần từ trái. */

.btm-hero {
  position: relative;
  isolation: isolate;
  min-height: 560px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: var(--bt-giay);
}

.btm-hero-anh {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: -2;
}

/* Lớp phủ giấy: đặc ở mép trái, tan dần về giữa để lộ ảnh bên phải. */
.btm-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: linear-gradient(96deg,
    var(--bt-giay) 0%,
    rgba(247, 240, 230, 0.97) 34%,
    rgba(247, 240, 230, 0.72) 50%,
    rgba(247, 240, 230, 0.12) 68%,
    rgba(247, 240, 230, 0) 82%);
}

.btm-hero-in {
  position: relative;
  max-width: 1280px;
  padding: 72px 0;
}

.rt3-museum-page .btm-hero-in > .rt3-eyebrow { margin: 0 0 18px; color: var(--bt-nhan); }

.rt3-museum-page .btm-hero h1 {
  margin: 0 0 22px;
  font-family: "Playfair Display", Georgia, serif;
  font-size: clamp(32px, 4vw, 54px);
  font-weight: 400;
  line-height: 1.16;
  color: var(--bt-man);
}

.rt3-museum-page .btm-lead {
  margin: 0;
  max-width: 46ch;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--bt-nau-2);
}

/* Ba thông số, ngăn nhau bằng một vạch mảnh */
.btm-so {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0;
  margin: 40px 0 0;
  padding: 0;
  list-style: none;
}

.btm-so li {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 30px;
  border-left: 1px solid var(--bt-vien);
}

.btm-so li:first-child { padding-left: 0; border-left: 0; }

.btm-i     { flex: none; width: 30px; height: 30px; color: var(--bt-nhan); }
.btm-i-nho { flex: none; width: 17px; height: 17px; color: var(--bt-nhan); }

.btm-so span { display: block; font-size: 11.5px; line-height: 1.5; color: var(--bt-nau-3); }

.btm-so b {
  display: block;
  font-family: "Playfair Display", Georgia, serif;
  font-size: 21px;
  font-weight: 500;
  line-height: 1.2;
  color: var(--bt-nau);
}

/* --------------------------------------------------- Tiêu đề giữa + thoi */

.btm-dau { margin: 0 0 54px; text-align: center; }

.rt3-museum-page .btm-dau > .rt3-eyebrow { margin: 0 0 10px; color: var(--bt-nhan); }

.rt3-museum-page .btm-dau h2 {
  margin: 0;
  font-family: "Playfair Display", Georgia, serif;
  font-size: clamp(26px, 2.8vw, 36px);
  font-weight: 400;
  line-height: 1.24;
  color: var(--bt-man);
}

/* Vạch mảnh có hình thoi ở giữa */
.btm-thoi {
  position: relative;
  display: block;
  width: 210px;
  height: 1px;
  margin: 22px auto 0;
  background: var(--btm-vien2);
}

.btm-thoi::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  width: 7px;
  height: 7px;
  background: var(--btm-vien2);
  transform: translate(-50%, -50%) rotate(45deg);
}

/* ------------------------------------------------ Ba khu, xếp so le */

.btm-khu-khoi { background: var(--bt-giay); }

.btm-khu-ds { display: grid; gap: 30px; }

.btm-khu {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  align-items: stretch;
  gap: 0;
  background: #fdf9f2;
  border: 1px solid var(--bt-vien);
}

/* Hàng chẵn đảo chiều: chữ bên trái, ảnh bên phải. */
.btm-khu:nth-child(even) .btm-khu-anh { order: 2; }

.btm-khu-anh {
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  background: #d7c5af;
}

.btm-khu-anh img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 720ms cubic-bezier(0.2, 0.72, 0.2, 1);
}

.btm-khu:hover .btm-khu-anh img { transform: scale(1.05); }

.btm-khu-noi {
  display: flex;
  min-height: 100%;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  gap: 14px;
  padding: 46px 52px;
}

.rt3-museum-page .btm-khu-so {
  margin: 0 0 2px;
  font-family: "Playfair Display", Georgia, serif;
  font-size: clamp(38px, 3.6vw, 52px);
  font-weight: 400;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--btm-vang);
}

.rt3-museum-page .btm-khu h3 {
  margin: 0;
  font-family: "Playfair Display", Georgia, serif;
  font-size: clamp(21px, 2.1vw, 27px);
  font-weight: 400;
  line-height: 1.26;
  color: var(--bt-man);
}

.rt3-museum-page .btm-khu h3 a { color: inherit; text-decoration: none; }
.rt3-museum-page .btm-khu h3 a:hover { color: var(--bt-nhan); }

/* :not() để luật này không đè cỡ chữ của số thứ tự lớn — số cũng là một <p>. */
.rt3-museum-page .btm-khu-noi p:not(.btm-khu-so) {
  margin: 0;
  max-width: 44ch;
  font-size: 13.5px;
  line-height: 1.85;
  color: var(--bt-nau-2);
}

/* Nút đặc màu mận */
.rt3-museum-page a.btm-nut {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-top: 8px;
  padding: 12px 26px;
  background: var(--bt-man);
  border: 1px solid var(--bt-man);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: #fff;
  text-decoration: none;
  transition: background 220ms ease, color 220ms ease;
}

.rt3-museum-page a.btm-nut:hover { background: #451017; border-color: #451017; color: #fff; }
.btm-nut i { font-style: normal; }

/* ------------------------------------------------------- Sơ đồ bảo tàng */

.btm-sodo-khoi { background: var(--bt-giay); padding-top: 0; }

.btm-sodo {
  display: grid;
  grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.4fr);
  align-items: center;
  gap: 46px;
  padding: 40px 46px;
  background: #fdf9f2;
  border: 1px solid var(--bt-vien);
}

.rt3-museum-page .btm-sodo-copy h2 {
  margin: 0 0 10px;
  font-family: "Playfair Display", Georgia, serif;
  font-size: clamp(22px, 2.3vw, 29px);
  font-weight: 400;
  color: var(--bt-man);
}

.rt3-museum-page .btm-sodo-copy > p {
  margin: 0 0 26px;
  font-size: 13px;
  line-height: 1.8;
  color: var(--bt-nau-2);
}

.btm-chugiai {
  margin: 0 0 26px;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.btm-chugiai li { display: flex; align-items: center; gap: 12px; }

.btm-cham {
  flex: none;
  display: grid;
  place-items: center;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--cham, var(--bt-man));
  font-size: 11px;
  font-weight: 600;
  color: #fff;
}

.rt3-museum-page .btm-chugiai a {
  font-size: 13px;
  color: var(--bt-nau);
  text-decoration: none;
}

.rt3-museum-page .btm-chugiai a:hover { color: var(--bt-nhan); text-decoration: underline; }

.btm-tienich {
  margin: 0;
  padding: 22px 0 0;
  border-top: 1px solid var(--bt-vien);
  list-style: none;
  display: grid;
  gap: 11px;
}

.btm-tienich li {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 12.5px;
  color: var(--bt-nau-2);
}

.btm-mui-ten {
  flex: none;
  width: 17px;
  text-align: center;
  color: var(--bt-nhan);
}

.btm-sodo-anh { margin: 0; }

.btm-sodo-anh img {
  width: 100%;
  height: auto;
  background: #fdfaf4;
  border: 1px solid var(--bt-vien);
}

/* ------------------------------------------------------ Hiện vật nổi bật */

.btm-noibat-khoi { background: var(--bt-giay); padding-top: 0; }

.btm-dau-hang {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin: 0 0 28px;
}

.rt3-museum-page .btm-dau-hang h2 {
  margin: 0;
  font-family: "Playfair Display", Georgia, serif;
  font-size: clamp(22px, 2.3vw, 30px);
  font-weight: 400;
  color: var(--bt-man);
}

.rt3-museum-page a.btm-xem-het {
  font-size: 10.5px;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--bt-nhan);
  text-decoration: none;
}

.rt3-museum-page a.btm-xem-het:hover { color: var(--bt-man); }
.btm-xem-het i { font-style: normal; }

.btm-hv-luoi {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 24px;
}

.btm-hv {
  display: flex;
  flex-direction: column;
  background: #fdf9f2;
  border: 1px solid var(--bt-vien);
  animation: btHien 640ms cubic-bezier(0.2, 0.72, 0.2, 1) calc(var(--i, 0) * 80ms) 1 both;
}

.btm-hv-anh {
  display: block;
  overflow: hidden;
  aspect-ratio: 5 / 4;
  background: #2b1d17;
}

.btm-hv-anh img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 720ms cubic-bezier(0.2, 0.72, 0.2, 1);
}

.btm-hv:hover .btm-hv-anh img { transform: scale(1.06); }

.btm-hv-chan {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 16px;
}

.btm-hv-chan > div { min-width: 0; }

.rt3-museum-page .btm-hv h3 {
  margin: 0 0 3px;
  font-family: "Playfair Display", Georgia, serif;
  font-size: 15px;
  font-weight: 400;
  line-height: 1.3;
  color: var(--bt-nau);
}

.rt3-museum-page .btm-hv h3 a { color: inherit; text-decoration: none; }
.rt3-museum-page .btm-hv h3 a:hover { color: var(--bt-nhan); }

.rt3-museum-page .btm-hv small {
  display: block;
  font-size: 11px;
  color: var(--bt-nau-3);
}

.rt3-museum-page a.btm-hv-lien {
  flex: none;
  font-size: 10.5px;
  color: var(--bt-nhan);
  text-decoration: none;
  white-space: nowrap;
}

.rt3-museum-page a.btm-hv-lien:hover { color: var(--bt-man); text-decoration: underline; }
.btm-hv-lien i { font-style: normal; }

/* ================================== khổ nhỏ ================================== */

@media (max-width: 1100px) {
  .btm-hv-luoi { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .btm-khu-noi { padding: 34px 34px; }
}

@media (max-width: 980px) {
  .btm-hero { min-height: 0; }

  /* Ảnh chuyển thành một khối riêng phía trên, chữ nằm dưới trên nền giấy. */
  .btm-hero-anh { position: relative; height: 300px; z-index: 0; }
  .btm-hero::before { content: none; }
  .btm-hero { display: block; }
  .btm-hero-in { padding: 34px 0 46px; }

  .btm-khu { grid-template-columns: minmax(0, 1fr); }
  .btm-khu:nth-child(even) .btm-khu-anh { order: 0; }
  .btm-khu-anh { aspect-ratio: 16 / 9; }

  .btm-sodo { grid-template-columns: minmax(0, 1fr); gap: 30px; padding: 30px 26px; }
}

@media (max-width: 680px) {
  /* Tiêu đề và link "xem tất cả" xuống dòng thay vì tràn ra ngoài khung. */
  .btm-dau-hang { display: grid; gap: 8px; }

  .btm-hv-chan { flex-direction: column; align-items: flex-start; gap: 6px; }
  .rt3-museum-page a.btm-hv-lien { white-space: normal; }

  .btm-so { gap: 16px 0; }
  .btm-so li { padding: 0 18px; }
  .btm-so li:nth-child(1),
  .btm-so li:nth-child(3) { padding-left: 0; border-left: 0; }

  .btm-khu-noi { padding: 28px 22px; }
  .btm-hv-luoi { grid-template-columns: minmax(0, 1fr); }
  .btm-dau { text-align: left; }
  .btm-thoi { margin-left: 0; }
}

@media (prefers-reduced-motion: reduce) {
  .btm-hv { animation: none; }
  .btm-khu-anh img, .btm-hv-anh img { transition: none; }
}