:root {
      --blue-950: #0b2f4d;
      --blue-900: #0f3f66;
      --blue-700: #1f6f9f;
      --blue-500: #49a7d8;
      --blue-100: #eaf7fd;
      --blue-50: #f5fbfe;
      --green-600: #21856f;
      --ink: #1d2935;
      --muted: #607080;
      --line: #d9edf6;
      --white: #ffffff;
      --shadow: 0 16px 40px rgba(15, 63, 102, 0.11);
      --radius: 12px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      margin: 0;
      font-family: Arial, sans-serif;
      color: var(--ink);
      background: var(--white);
      line-height: 1.65;
    }

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

    .container {
      width: min(1120px, calc(100% - 32px));
      margin: 0 auto;
    }

    .topbar {
      background: var(--blue-900);
      color: var(--white);
      font-size: 14px;
    }

    .topbar-inner {
      min-height: 40px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 16px;
    }

    .header {
      position: sticky;
      top: 0;
      z-index: 20;
      background: rgba(255, 255, 255, 0.96);
      border-bottom: 1px solid var(--line);
      backdrop-filter: blur(12px);
    }

    .header-inner {
      min-height: 76px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 24px;
    }

    .brand {
      min-width: 250px;
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .brand-logo {
      width: 44px;
      height: 44px;
      border-radius: 6px;
      object-fit: contain;
      background: #06151e;
      padding: 4px;
      flex: 0 0 auto;
    }

    .brand strong {
      display: block;
      color: var(--blue-900);
      font-size: 18px;
      line-height: 1.2;
    }

    .brand span span {
      display: block;
      color: var(--muted);
      font-size: 13px;
      margin-top: 3px;
    }

    .nav {
      display: flex;
      align-items: center;
      gap: 22px;
      color: #405466;
      font-size: 14px;
      white-space: nowrap;
    }

    .nav a,
    .nav summary {
      color: #405466;
      font: inherit;
      cursor: pointer;
    }

    .nav a:hover,
    .nav summary:hover {
      color: var(--blue-700);
    }

    .nav-item {
      position: relative;
    }

    .nav-item summary {
      list-style: none;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }

    .nav-item summary::-webkit-details-marker {
      display: none;
    }

    .nav-caret {
      width: 7px;
      height: 7px;
      border-right: 1.8px solid currentColor;
      border-bottom: 1.8px solid currentColor;
      transform: rotate(45deg);
      margin-top: -3px;
      transition: transform 180ms ease;
    }

    .nav-item[open] .nav-caret,
    .nav-item:hover .nav-caret {
      transform: rotate(225deg);
      margin-top: 3px;
    }

    .nav-dropdown {
      position: absolute;
      top: calc(100% + 14px);
      left: 0;
      min-width: 190px;
      display: none;
      padding: 8px;
      background: var(--white);
      border: 1px solid var(--line);
      border-radius: 12px;
      box-shadow: 0 16px 34px rgba(15, 63, 102, 0.14);
    }

    .nav-item:hover .nav-dropdown,
    .nav-item[open] .nav-dropdown {
      display: grid;
      gap: 4px;
    }

    .nav-dropdown a {
      display: block;
      padding: 11px 12px;
      border-radius: 8px;
      color: var(--blue-900);
      font-weight: 700;
    }

    .nav-dropdown a:hover,
    .nav-dropdown a:focus {
      background: var(--blue-50);
      color: var(--blue-700);
      outline: none;
    }

    .menu-toggle {
      display: none;
      align-items: center;
      justify-content: center;
      width: 44px;
      height: 44px;
      border-radius: 8px;
      border: 1px solid var(--line);
      background: var(--white);
      color: var(--blue-900);
      cursor: pointer;
      flex-direction: column;
      gap: 5px;
    }

    .menu-toggle span,
    .menu-toggle::before,
    .menu-toggle::after {
      content: "";
      display: block;
      width: 20px;
      height: 2px;
      background: currentColor;
      border-radius: 999px;
      transition: transform 180ms ease, opacity 180ms ease;
    }

    .header.menu-open .menu-toggle::before {
      transform: translateY(7px) rotate(45deg);
    }

    .header.menu-open .menu-toggle span {
      opacity: 0;
    }

    .header.menu-open .menu-toggle::after {
      transform: translateY(-7px) rotate(-45deg);
    }

    .button {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      min-height: 44px;
      padding: 0 18px;
      border-radius: 8px;
      border: 1px solid transparent;
      font-weight: 700;
      font-size: 14px;
      cursor: pointer;
    }

    .button-primary {
      background: var(--blue-700);
      color: var(--white);
      box-shadow: 0 10px 24px rgba(31, 111, 159, 0.22);
    }

    .button-secondary {
      background: var(--white);
      color: var(--blue-900);
      border-color: var(--line);
    }

    .button-soft {
      background: var(--blue-50);
      color: var(--blue-900);
      border-color: var(--line);
    }

    .hero {
      background: linear-gradient(180deg, var(--blue-50), var(--white));
      padding: 72px 0 56px;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: minmax(0, 1.06fr) minmax(320px, 0.94fr);
      gap: 46px;
      align-items: center;
    }

    .eyebrow {
      color: var(--blue-700);
      font-weight: 700;
      margin: 0 0 10px;
    }

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

    h1 {
      color: var(--blue-900);
      font-size: clamp(38px, 5vw, 58px);
      line-height: 1.06;
      margin-bottom: 14px;
    }

    .hero-title {
      font-size: clamp(30.72px, 3.2vw, 46.08px);
      line-height: 1.05;
      white-space: nowrap;
    }

    .hero-subtitle {
      color: var(--blue-700);
      font-size: 22px;
      font-weight: 700;
      margin-bottom: 18px;
    }

    .lead {
      color: #405466;
      font-size: 18px;
      max-width: 720px;
    }

    .hero-actions,
    .cta-actions {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 26px;
    }

    .doctor-photo {
      width: 100%;
      max-width: 360px;
      justify-self: center;
      border-radius: 18px;
      border: 1px solid var(--line);
      background: var(--white);
      box-shadow: var(--shadow);
      overflow: hidden;
    }

    .doctor-photo img {
      width: 100%;
      height: auto;
      min-height: 0;
      display: block;
      object-fit: cover;
      object-position: center top;
    }

    section {
      padding: 64px 0;
    }

    .section-head {
      display: flex;
      justify-content: space-between;
      align-items: end;
      gap: 24px;
      margin-bottom: 28px;
    }

    .section-head h2 {
      color: var(--blue-900);
      font-size: 32px;
      line-height: 1.2;
      margin-bottom: 8px;
    }

    .section-head p {
      color: var(--muted);
      max-width: 640px;
      margin-bottom: 0;
    }

    .soft-band {
      background: var(--blue-50);
    }

    .card-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 18px;
    }

    .info-card {
      position: relative;
      overflow: hidden;
      display: flex;
      flex-direction: column;
      min-height: 100%;
      padding: 22px;
      border: 1px solid var(--line);
      border-radius: var(--radius);
      background: var(--white);
      box-shadow: 0 10px 24px rgba(15, 63, 102, 0.06);
      transition: transform 280ms ease, box-shadow 280ms ease, border-color 280ms ease, background-color 280ms ease;
    }

    .expertise-card {
      --accent: var(--blue-700);
      --hover-bg: var(--blue-50);
      color: inherit;
    }

    .expertise-card.knee {
      --accent: #0f5f8f;
      --hover-bg: #f0f8fc;
    }

    .expertise-card.hip {
      --accent: #0f766e;
      --hover-bg: #effaf8;
    }

    .expertise-card.sports-focus {
      --accent: #2563eb;
      --hover-bg: #f1f6ff;
    }

    .expertise-card::before {
      content: "";
      position: absolute;
      left: 22px;
      right: 22px;
      top: 0;
      height: 4px;
      border-radius: 999px;
      background: var(--accent);
      transform: scaleX(0);
      transform-origin: left;
      transition: transform 280ms ease;
    }

    .expertise-card:hover,
    .expertise-card:focus-visible,
    .expertise-card:active {
      transform: translateY(-6px);
      border-color: var(--accent);
      background: var(--hover-bg);
      box-shadow: 0 18px 42px rgba(15, 23, 42, 0.12);
      outline: none;
    }

    .expertise-card:focus-visible {
      outline: 3px solid rgba(15, 95, 143, 0.28);
      outline-offset: 4px;
    }

    .expertise-card:hover::before,
    .expertise-card:focus-visible::before,
    .expertise-card:active::before {
      transform: scaleX(1);
    }

    .info-card h3 {
      color: var(--blue-900);
      font-size: 21px;
      line-height: 1.3;
      margin-bottom: 10px;
      transition: color 280ms ease, transform 280ms ease;
    }

    .info-card p {
      color: #405466;
      margin-bottom: 18px;
      transition: color 280ms ease;
    }

    .text-link {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      color: var(--blue-700);
      font-weight: 700;
      margin-top: auto;
      transition: color 280ms ease, transform 280ms ease;
    }

    .text-link .arrow {
      display: inline-block;
      transition: transform 280ms ease;
    }

    .expertise-card:hover h3,
    .expertise-card:focus-visible h3,
    .expertise-card:active h3 {
      color: var(--accent);
      transform: translateX(2px);
    }

    .expertise-card:hover p,
    .expertise-card:focus-visible p,
    .expertise-card:active p {
      color: #12324a;
    }

    .expertise-card:hover .text-link,
    .expertise-card:focus-visible .text-link,
    .expertise-card:active .text-link {
      color: var(--accent);
      transform: translateX(4px);
    }

    .expertise-card:hover .text-link .arrow,
    .expertise-card:focus-visible .text-link .arrow,
    .expertise-card:active .text-link .arrow {
      transform: translateX(4px);
    }

    .timeline {
      display: grid;
      gap: 14px;
      position: relative;
    }

    .timeline-item {
      display: grid;
      grid-template-columns: 150px minmax(0, 1fr);
      gap: 18px;
      padding: 20px;
      border: 1px solid var(--line);
      border-radius: var(--radius);
      background: var(--white);
    }

    .timeline-year {
      color: var(--blue-700);
      font-weight: 700;
      font-size: 18px;
    }

    .timeline-item p {
      color: #405466;
      margin-bottom: 0;
    }

    .activity-wrap {
      display: grid;
      grid-template-columns: minmax(0, 0.95fr) minmax(280px, 1.05fr);
      gap: 28px;
      align-items: start;
    }

    .activity-list,
    .fit-list {
      display: grid;
      gap: 12px;
      margin: 0;
      padding: 0;
      list-style: none;
    }

    .activity-list li,
    .fit-list li {
      border: 1px solid var(--line);
      border-radius: 10px;
      background: var(--white);
      padding: 14px 16px;
      color: #405466;
    }

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

    .fit-list li {
      display: flex;
      gap: 10px;
      align-items: flex-start;
    }

    .fit-list li::before {
      content: "";
      width: 9px;
      height: 9px;
      border-radius: 50%;
      background: var(--blue-500);
      margin-top: 9px;
      flex: 0 0 auto;
    }

    .process-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 14px;
      counter-reset: step;
    }

    .process-step {
      counter-increment: step;
      padding: 20px;
      border: 1px solid var(--line);
      border-left: 3px solid var(--blue-500);
      border-radius: var(--radius);
      background: var(--white);
      box-shadow: 0 10px 24px rgba(15, 63, 102, 0.06);
    }

    .process-step::before {
      content: "Bước " counter(step);
      display: block;
      color: var(--blue-700);
      font-weight: 700;
      margin-bottom: 10px;
    }

    .process-step h3 {
      color: var(--blue-900);
      font-size: 18px;
      line-height: 1.3;
      margin-bottom: 8px;
    }

    .process-step p {
      color: #405466;
      margin-bottom: 0;
    }

    .cta {
      background: linear-gradient(135deg, var(--blue-900), var(--green-600));
      color: var(--white);
      padding: 54px 0;
    }

    .cta h2 {
      color: var(--white);
      font-size: 32px;
      line-height: 1.25;
      margin-bottom: 10px;
    }

    .cta p {
      color: rgba(255, 255, 255, 0.85);
      max-width: 740px;
      margin-bottom: 0;
    }

    .footer {
      background: var(--blue-950);
      color: rgba(255, 255, 255, 0.76);
      padding: 34px 0;
      font-size: 14px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.8fr 1fr;
      gap: 24px;
    }

    .footer strong {
      color: var(--white);
      display: block;
      margin-bottom: 8px;
    }
    @media (max-width: 940px) {
      .header-inner {
        position: relative;
      }

      .menu-toggle {
        display: inline-flex;
      }

      .nav {
        position: absolute;
        top: calc(100% + 1px);
        left: 0;
        right: 0;
        display: none;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        padding: 12px;
        background: var(--white);
        border: 1px solid var(--line);
        border-top: 0;
        border-radius: 0 0 14px 14px;
        box-shadow: 0 18px 36px rgba(15, 63, 102, 0.13);
        white-space: normal;
      }

      .header.menu-open .nav {
        display: flex;
      }

      .nav > a,
      .nav summary {
        min-height: 46px;
        display: flex;
        align-items: center;
        justify-content: space-between;
        padding: 0 10px;
        border-radius: 8px;
        font-size: 16px;
      }

      .nav > a:hover,
      .nav summary:hover {
        background: var(--blue-50);
      }

      .nav-dropdown {
        position: static;
        min-width: 0;
        box-shadow: none;
        border: 0;
        border-left: 2px solid var(--line);
        border-radius: 0;
        margin: 2px 0 8px 14px;
        padding: 4px 0 4px 10px;
      }

      .nav-item:hover .nav-dropdown {
        display: none;
      }

      .nav-item[open] .nav-dropdown {
        display: grid;
      }

      .hero-grid,
      .activity-wrap {
        grid-template-columns: 1fr;
      }

      .card-grid,
      .process-grid {
        grid-template-columns: repeat(2, 1fr);
      }

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

    @media (max-width: 640px) {
      .topbar {
        display: none;
      }

      .brand {
        min-width: 0;
      }

      .brand-logo {
        width: 38px;
        height: 38px;
      }

      .brand strong {
        font-size: 16px;
      }

      .header .button-primary {
        display: none;
      }

      .hero {
        padding: 44px 0 38px;
      }

      h1 {
        font-size: 34px;
      }

      .hero-title {
        font-size: 26.88px;
        white-space: normal;
      }

      .hero-subtitle {
        font-size: 18px;
      }

      .lead {
        font-size: 16px;
      }

      section {
        padding: 44px 0;
      }

      .section-head {
        display: block;
      }

      .section-head h2,
      .cta h2 {
        font-size: 26px;
      }

      .card-grid,
      .process-grid,
      .fit-list {
        grid-template-columns: 1fr;
      }

      .timeline-item {
        grid-template-columns: 1fr;
        gap: 6px;
      }

      .doctor-photo img {
        min-height: 0;
      }
    }