:root {
  --blue: #0b4ab3;
  --blue-deep: #07317c;
  --red: #b83225;
  --yellow: #ffd92f;
  --ink: #172033;
  --muted: #5d667a;
  --paper: #fffdf5;
  --soft: #eef4ff;
  --green: #3d7d58;
  --line: rgba(23, 32, 51, 0.14);
  --shadow: 0 18px 44px rgba(7, 49, 124, 0.18);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.6;
}

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

a {
  color: inherit;
  text-decoration: none;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 64px;
  padding: 10px clamp(18px, 4vw, 56px);
  color: #fff;
  background: rgba(7, 49, 124, 0.94);
  backdrop-filter: blur(12px);
}

.brand {
  max-width: 360px;
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  font-weight: 700;
  line-height: 1.28;
  letter-spacing: 0;
}

.nav {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 700;
}

.nav a {
  padding: 9px 10px;
}

.nav-cta {
  color: var(--ink);
  background: var(--yellow);
  border-radius: 6px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.04fr) minmax(320px, 0.8fr);
  gap: clamp(28px, 5vw, 68px);
  align-items: center;
  min-height: calc(100vh - 64px);
  padding: clamp(34px, 6vw, 72px) clamp(18px, 5vw, 76px);
  color: #fff;
  background:
    linear-gradient(135deg, rgba(7, 49, 124, 0.98), rgba(11, 74, 179, 0.92) 48%, rgba(184, 50, 37, 0.9)),
    url("assets/bia2.jpg") center/cover;
}

.hero-copy {
  max-width: 760px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--yellow);
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 780px;
  margin-bottom: 12px;
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  font-size: clamp(42px, 8vw, 92px);
  font-weight: 800;
  line-height: 1.06;
  letter-spacing: 0;
  text-transform: uppercase;
}

h2 {
  margin-bottom: 16px;
  font-size: clamp(30px, 5vw, 54px);
  line-height: 1.05;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 8px;
  font-size: 22px;
  line-height: 1.2;
}

.subtitle {
  display: inline-block;
  margin-bottom: 20px;
  padding: 8px 12px;
  color: var(--ink);
  background: var(--yellow);
  border-radius: 6px;
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  font-size: clamp(18px, 2.6vw, 28px);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: 0;
}

.lead {
  max-width: 680px;
  color: rgba(255, 255, 255, 0.9);
  font-size: 18px;
}

.price-strip {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin: 28px 0 24px;
}

.old-price {
  color: rgba(255, 255, 255, 0.72);
  font-size: 24px;
  text-decoration: line-through;
}

.price-strip strong {
  color: var(--yellow);
  font-size: clamp(42px, 7vw, 70px);
  line-height: 1;
}

.ship {
  padding: 7px 10px;
  color: #fff;
  background: var(--green);
  border-radius: 6px;
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  font-weight: 700;
  line-height: 1.25;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 28px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 48px;
  padding: 13px 18px;
  border: 0;
  border-radius: 6px;
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.25;
  cursor: pointer;
}

.button svg {
  width: 20px;
  height: 20px;
  fill: currentColor;
  flex: 0 0 auto;
}

.primary {
  color: var(--ink);
  background: var(--yellow);
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.18);
}

.secondary {
  color: #fff;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.36);
}

.full {
  width: 100%;
}

.quick-facts {
  display: grid;
  grid-template-columns: repeat(4, minmax(90px, 1fr));
  gap: 8px;
  max-width: 620px;
}

.quick-facts span {
  display: grid;
  min-height: 52px;
  place-items: center;
  padding: 8px;
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.1);
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  font-weight: 700;
  line-height: 1.25;
  text-align: center;
}

.hero-media {
  justify-self: center;
  width: min(440px, 100%);
  transform: rotate(1.5deg);
  filter: drop-shadow(0 24px 30px rgba(0, 0, 0, 0.34));
}

.hero-media img {
  width: 100%;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  border-radius: 8px;
  border: 6px solid rgba(255, 255, 255, 0.18);
}

section {
  padding: clamp(58px, 9vw, 108px) clamp(18px, 5vw, 76px);
}

.band {
  background: #fff;
}

.section-heading {
  max-width: 920px;
  margin: 0 auto 34px;
  text-align: center;
}

.section-heading .eyebrow,
.author-copy .eyebrow,
.order-panel .eyebrow {
  color: var(--red);
}

.problem-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 26px;
  max-width: 1040px;
  margin: 0 auto;
  font-size: 19px;
}

.pill-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  max-width: 1120px;
  margin: 0 auto;
}

.pill-grid article {
  min-height: 190px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 8px 18px rgba(23, 32, 51, 0.05);
}

.pill-grid span {
  display: inline-block;
  margin-bottom: 12px;
  color: var(--blue);
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  font-size: 13px;
  font-weight: 700;
  line-height: 1.25;
  text-transform: uppercase;
}

.pill-grid p {
  color: var(--muted);
}

.toc-section {
  background: linear-gradient(180deg, #fff, var(--paper));
}

.toc-gallery {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  max-width: 980px;
  margin: 0 auto;
}

.toc-page {
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 12px 26px rgba(23, 32, 51, 0.07);
  cursor: zoom-in;
}

.toc-page img {
  width: 100%;
  height: auto;
  border-radius: 6px;
}

.who {
  background: linear-gradient(180deg, #fff, var(--soft));
}

.check-list {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 12px;
  max-width: 1180px;
  margin: 0 auto;
}

.check-list p {
  min-height: 150px;
  margin: 0;
  padding: 20px;
  border-left: 5px solid var(--red);
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 8px 18px rgba(23, 32, 51, 0.05);
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  font-weight: 700;
  line-height: 1.55;
}

.preview-section {
  background: var(--paper);
}

.gallery {
  display: grid;
  grid-template-columns: 1.2fr repeat(2, minmax(0, 0.8fr));
  gap: 14px;
  max-width: 1120px;
  margin: 0 auto;
}

.gallery-item {
  position: relative;
  min-height: 220px;
  padding: 0;
  border: 0;
  border-radius: 8px;
  overflow: hidden;
  background: #dfe6f4;
  cursor: zoom-in;
}

.gallery-item.large {
  grid-row: span 2;
  min-height: 500px;
}

.gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 180ms ease;
}

.gallery-item:hover img {
  transform: scale(1.03);
}

.quote-band {
  color: #fff;
  background:
    linear-gradient(90deg, rgba(7, 49, 124, 0.93), rgba(184, 50, 37, 0.9)),
    url("assets/trangtrong5.jpg") center/cover;
}

.quote-band div {
  max-width: 920px;
  margin: 0 auto;
  text-align: center;
}

.quote {
  margin-bottom: 12px;
  color: var(--yellow);
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  font-size: clamp(28px, 5vw, 52px);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: 0;
}

.testimonials-section {
  background: linear-gradient(180deg, var(--paper), #fff);
}

.testimonial-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  max-width: 1120px;
  margin: 0 auto;
}

.testimonial-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 360px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 12px 26px rgba(23, 32, 51, 0.07);
}

.testimonial-card p {
  position: relative;
  margin-bottom: 22px;
  color: var(--ink);
  font-size: 17px;
}

.testimonial-card p::before {
  content: "“";
  position: absolute;
  top: -28px;
  left: -4px;
  color: rgba(184, 50, 37, 0.16);
  font-size: 84px;
  font-weight: 900;
  line-height: 1;
}

.testimonial-card strong,
.testimonial-card span {
  display: block;
}

.testimonial-card strong {
  color: var(--blue-deep);
  font-size: 20px;
}

.testimonial-card span {
  color: var(--muted);
  font-weight: 700;
}

.author-section {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(300px, 0.7fr);
  gap: clamp(24px, 5vw, 64px);
  align-items: center;
  background: #fff;
}

.author-copy {
  max-width: 720px;
}

.author-copy p:not(.eyebrow) {
  color: var(--muted);
  font-size: 18px;
}

.author-media img {
  width: 100%;
  max-height: 560px;
  object-fit: cover;
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.order-section {
  color: #fff;
  background: var(--blue-deep);
}

.order-panel {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(320px, 0.7fr);
  gap: clamp(24px, 5vw, 60px);
  align-items: start;
  max-width: 1100px;
  margin: 0 auto;
}

.order-panel .eyebrow {
  color: var(--yellow);
}

.order-note {
  color: rgba(255, 255, 255, 0.86);
  font-size: 19px;
}

.order-price {
  display: flex;
  align-items: end;
  gap: 16px;
  margin-top: 22px;
}

.order-price span {
  color: rgba(255, 255, 255, 0.62);
  font-size: 26px;
  text-decoration: line-through;
}

.order-price strong {
  color: var(--yellow);
  font-size: clamp(48px, 7vw, 74px);
  line-height: 1;
}

.order-form {
  padding: 22px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.1);
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
}

label {
  display: grid;
  gap: 7px;
  margin-bottom: 14px;
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  font-weight: 700;
  line-height: 1.35;
}

input,
textarea {
  width: 100%;
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: 6px;
  padding: 13px 12px;
  color: #fff;
  background: rgba(0, 0, 0, 0.18);
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.45;
}

input::placeholder,
textarea::placeholder {
  color: rgba(255, 255, 255, 0.62);
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  font-weight: 600;
}

.form-status {
  min-height: 26px;
  margin: 12px 0 0;
  color: var(--yellow);
  font-weight: 800;
}

.site-footer {
  padding: 28px clamp(18px, 5vw, 76px);
  color: #fff;
  background: #111827;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.2fr 0.9fr 1fr;
  gap: 20px;
  max-width: 1120px;
  margin: 0 auto;
}

.site-footer strong {
  display: block;
  margin-bottom: 8px;
  color: var(--yellow);
  font-size: 18px;
}

.site-footer p {
  margin: 0;
  color: rgba(255, 255, 255, 0.78);
}

.site-footer a {
  color: #fff;
  font-weight: 800;
}

.lightbox {
  width: min(92vw, 900px);
  border: 0;
  border-radius: 8px;
  padding: 0;
  background: transparent;
}

.lightbox::backdrop {
  background: rgba(0, 0, 0, 0.78);
}

.lightbox img {
  width: 100%;
  max-height: 88vh;
  object-fit: contain;
  background: #fff;
  border-radius: 8px;
}

.close {
  position: absolute;
  top: -42px;
  right: 0;
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  border: 0;
  border-radius: 6px;
  color: #fff;
  background: var(--red);
  font-size: 30px;
  line-height: 1;
  cursor: pointer;
}

@media (max-width: 980px) {
  .topbar {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
  }

  .nav {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .hero,
  .author-section,
  .order-panel {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .hero-media {
    width: min(360px, 86vw);
  }

  .pill-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .toc-gallery {
    grid-template-columns: 1fr;
    max-width: 620px;
  }

  .testimonial-grid {
    grid-template-columns: 1fr;
  }

  .testimonial-card {
    min-height: auto;
  }

  .check-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .gallery {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .footer-inner {
    grid-template-columns: 1fr;
  }

  .gallery-item.large {
    grid-column: 1 / -1;
    min-height: 440px;
  }
}

@media (max-width: 640px) {
  .brand {
    max-width: 260px;
  }

  .nav a {
    white-space: nowrap;
  }

  h1 {
    font-size: 42px;
  }

  .quick-facts,
  .problem-grid,
  .pill-grid,
  .check-list,
  .gallery {
    grid-template-columns: 1fr;
  }

  .quick-facts span {
    min-height: 44px;
  }

  .check-list p {
    min-height: auto;
  }

  .gallery-item,
  .gallery-item.large {
    min-height: 360px;
  }

  .hero-actions .button {
    width: 100%;
  }

  .order-price {
    align-items: flex-start;
    flex-direction: column;
    gap: 4px;
  }
}