:root {
  --brand: #0a819d;
  --brand-strong: #168dac;
  --ink: #222;
  --muted: #555;
  --paper: #fcfdfd;
  --header-height: 76px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans CJK SC", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; }
[hidden] { display: none !important; }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.skip-link {
  position: fixed;
  z-index: 1000;
  top: 8px;
  left: 8px;
  padding: 9px 14px;
  color: white;
  background: var(--brand);
  transform: translateY(-150%);
}
.skip-link:focus { transform: translateY(0); }

.site-header {
  position: relative;
  z-index: 20;
  min-height: var(--header-height);
  background: #fff;
  box-shadow: 0 1px 0 rgba(10, 129, 157, .08);
}
.header-inner {
  width: min(80%, 1345px);
  min-height: var(--header-height);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 28px;
}
.brand { justify-self: start; }
.brand img { width: 48px; height: 48px; object-fit: contain; }
.site-nav { display: flex; align-items: center; justify-content: center; gap: clamp(18px, 2.4vw, 42px); }
.site-nav a {
  position: relative;
  padding: 27px 0 24px;
  color: #282828;
  font-size: 15px;
  white-space: nowrap;
}
.site-nav a::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 17px;
  width: 0;
  height: 2px;
  background: var(--brand);
  transform: translateX(-50%);
  transition: width .2s ease;
}
.site-nav a:hover,
.site-nav a:focus-visible,
.site-nav a.active { color: var(--brand); }
.site-nav a:hover::after,
.site-nav a:focus-visible::after,
.site-nav a.active::after { width: 100%; }
.doctor-link {
  justify-self: end;
  padding: 9px 14px 8px;
  color: #fff;
  background: #1b86a0;
  border-radius: 2px;
  font-size: 15px;
  transition: background .2s ease, transform .2s ease;
}
.doctor-link:hover,
.doctor-link:focus-visible { background: #086f89; transform: translateY(-1px); }
.menu-toggle { display: none; }

.game-entry { display: flex; justify-content: center; padding: 20px 16px; background: #f1fafb; }
.game-entry[hidden] { display: none; }
.game-entry-button { display: inline-flex; align-items: center; gap: 24px; padding: 12px 28px; border-radius: 4px; background: #0a819d; color: #fff; font-size: 16px; font-weight: 600; }
.game-entry-button:hover { background: #086f89; }
.game-entry-button:focus-visible { outline: 3px solid #064a5b; outline-offset: 4px; }
@media (max-width: 767px) {
  .game-entry { padding: 16px; }
  .game-entry-button { padding: 11px 24px; font-size: 15px; }
}

.hero,
.image-section { background: #fff; }
.hero img,
.full-image { width: 100%; height: auto; }
.desktop-only { display: block; }
.mobile-only { display: none; }

.conditions { background: #fcfdfd; }
.conditions-title { background: #fcfdfd; }
.teeth-overview {
  width: min(82%, 1500px);
  min-height: 170px;
  margin: 22px auto 6px;
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  align-items: center;
  justify-items: center;
  gap: 18px;
}
.teeth-overview img { width: min(100%, 240px); max-height: 123px; object-fit: contain; }
.condition-tabs { width: min(1140px, 90%); margin: 6px auto 54px; }
.tab-list {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 18px;
  margin-bottom: 24px;
}
.tab-list button {
  min-height: 48px;
  padding: 10px 12px;
  border: 1px solid #d7edf2;
  border-radius: 3px;
  color: #3d5960;
  background: #fff;
  cursor: pointer;
  transition: color .2s ease, background .2s ease, border-color .2s ease;
}
.tab-list button:hover,
.tab-list button:focus-visible { border-color: var(--brand); color: var(--brand); }
.tab-list button[aria-selected="true"] { color: #fff; background: var(--brand-strong); border-color: var(--brand-strong); }
.tab-panels { min-height: 252px; background: #fff; }
.tab-panels img { width: 100%; height: auto; }

.faq { padding: 78px 24px 86px; background: #fff; }
.faq-inner { width: min(1345px, 92%); margin: 0 auto; }
.faq h2 { margin: 0 0 44px; text-align: center; font-size: 42px; font-weight: 400; }
.faq-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 42px 96px; }
.faq article { align-self: start; }
.faq h3 { margin: 0 0 12px; color: var(--brand); font-size: 22px; font-weight: 400; }
.faq p { margin: 0; color: #444; font-size: 15px; line-height: 1.9; }

.contact { padding: 66px 24px 56px; background: #fff; border-top: 1px solid #edf5f7; }
.contact-inner {
  width: min(1000px, 90%);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.25fr .75fr;
  align-items: center;
  gap: 90px;
}
.contact-heading { display: flex; align-items: center; gap: 12px; margin-bottom: 22px; }
.contact-heading img { width: 48px; height: 48px; }
.contact h2 { margin: 0; font-size: 24px; font-weight: 500; }
.contact-copy > p { display: flex; align-items: center; gap: 14px; margin: 14px 0; color: #555; font-size: 20px; }
.contact-copy > p img { width: 24px; height: 25px; object-fit: contain; }
.contact-copy strong { font-weight: 400; }
.contact-copy > a { display: inline-block; margin: 8px 0 0 38px; color: #aaa; font-size: 16px; }
.contact-copy > a:hover { color: var(--brand); }
.wechat { text-align: center; }
.wechat img { width: 118px; margin: 0 auto 18px; image-rendering: auto; }
.wechat p { margin: 0; color: #888; font-size: 16px; }
.site-footer { padding: 16px; text-align: center; color: #b0b0b0; background: #f7fbfc; font-size: 13px; }
.site-footer p { margin: 0; }

@media (max-width: 1100px) and (min-width: 768px) {
  .header-inner { width: 94%; gap: 16px; }
  .site-nav { gap: 14px; }
  .site-nav a { font-size: 14px; }
  .doctor-link { padding-inline: 10px; font-size: 14px; }
  .teeth-overview { width: 94%; gap: 8px; }
  .tab-list { gap: 8px; }
}

@media (max-width: 767px) {
  :root { --header-height: 62px; }
  .desktop-only { display: none !important; }
  .mobile-only { display: block; }
  .site-header { position: sticky; top: 0; }
  .header-inner {
    width: 100%;
    padding: 0 16px;
    grid-template-columns: 1fr auto auto;
    gap: 12px;
  }
  .brand img { width: 42px; height: 42px; }
  .doctor-link { padding: 8px 10px; font-size: 14px; }
  .menu-toggle {
    display: grid;
    width: 38px;
    height: 38px;
    padding: 9px;
    place-content: center;
    gap: 4px;
    border: 0;
    background: transparent;
    cursor: pointer;
  }
  .menu-toggle > span:not(.sr-only) { display: block; width: 20px; height: 2px; background: var(--brand); transition: transform .2s ease, opacity .2s ease; }
  .menu-toggle[aria-expanded="true"] > span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
  .menu-toggle[aria-expanded="true"] > span:nth-child(2) { opacity: 0; }
  .menu-toggle[aria-expanded="true"] > span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }
  .site-nav {
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0;
    padding: 8px 16px 14px;
    background: rgba(255, 255, 255, .98);
    box-shadow: 0 10px 20px rgba(17, 76, 89, .12);
    transform: translateY(-10px);
    opacity: 0;
    visibility: hidden;
    transition: opacity .2s ease, transform .2s ease, visibility .2s ease;
  }
  .site-nav.open { transform: translateY(0); opacity: 1; visibility: visible; }
  .site-nav a { padding: 13px 10px; text-align: center; font-size: 14px; }
  .site-nav a::after { bottom: 7px; }
  .mobile-stack img { width: 100%; height: auto; }
  .mobile-showcase { padding: 24px 0 0; background: #fff; }
  .carousel { position: relative; width: 100%; overflow: hidden; background: #fff; }
  .carousel-track { position: relative; min-height: min(115vw, 790px); }
  .slide { position: absolute; inset: 0; margin: 0; opacity: 0; visibility: hidden; transition: opacity .45s ease; }
  .slide.active { opacity: 1; visibility: visible; }
  .slide img { width: 100%; height: 100%; object-fit: contain; }
  .carousel-arrow {
    position: absolute;
    z-index: 2;
    top: 46%;
    width: 38px;
    height: 52px;
    border: 0;
    border-radius: 3px;
    color: #fff;
    background: rgba(10, 129, 157, .56);
    font-size: 34px;
    line-height: 1;
    cursor: pointer;
  }
  .carousel-arrow.prev { left: 8px; }
  .carousel-arrow.next { right: 8px; }
  .carousel-dots { position: absolute; z-index: 3; right: 0; bottom: 12px; left: 0; display: flex; justify-content: center; gap: 7px; }
  .carousel-dots button { width: 8px; height: 8px; padding: 0; border: 0; border-radius: 50%; background: #b9dce4; cursor: pointer; }
  .carousel-dots button[aria-current="true"] { background: var(--brand); transform: scale(1.25); }
  .mobile-advantages { width: 100%; height: auto; margin-top: 14px; }
  .mobile-contact { position: relative; container-type: inline-size; background: #fff; }
  .mobile-phone-fix {
    position: absolute;
    top: 22.7%;
    left: 51.1%;
    padding: 0 0.35%;
    background: #fff;
    color: #606060;
    font: 400 3.62cqw/1.18 Arial, "Microsoft YaHei", sans-serif;
    white-space: nowrap;
  }
  .mobile-icp { position: absolute; left: 11%; top: 48%; color: transparent; font-size: 1px; width: 45%; height: 9%; }
  .site-footer { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
}