/* ============================================================
   和尔泰医疗 · Heertai Medical
   Palette: 深海蓝 #16548F / 墨青 #142838 / 晨雾 #EDF3F9
            氧白 #FAFCFE / 呼吸青 #2FA8A0
   Type:    Display — Noto Serif SC · Body — Noto Sans SC · Data — mono
   ============================================================ */

:root{
  --blue:      #16548F;
  --blue-deep: #0E3C68;
  --ink:       #142838;
  --ink-soft:  #4A5D6E;
  --mist:      #EDF3F9;
  --mist-2:    #E1EBF4;
  --paper:     #FAFCFE;
  --white:     #FFFFFF;
  --teal:      #2FA8A0;
  --teal-deep: #1F837C;
  --line:      #D5E2ED;

  --serif: "Noto Serif SC","Songti SC","STSong","SimSun",serif;
  --sans:  "Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --mono:  "IBM Plex Mono","SFMono-Regular",Consolas,"Courier New",monospace;

  --radius: 14px;
  --shadow: 0 10px 34px rgba(20,60,104,.10);
  --maxw: 1120px;
}

*{ margin:0; padding:0; box-sizing:border-box; }
html{ scroll-behavior:smooth; }
@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior:auto; }
  *,*::before,*::after{ animation:none !important; transition:none !important; }
}

body{
  font-family:var(--sans);
  color:var(--ink);
  background:var(--paper);
  line-height:1.75;
  font-size:16px;
  -webkit-font-smoothing:antialiased;
}

img{ max-width:100%; display:block; }
a{ color:inherit; text-decoration:none; }
ul{ list-style:none; }

.wrap{ max-width:var(--maxw); margin:0 auto; padding:0 24px; }

::selection{ background:var(--blue); color:#fff; }

:focus-visible{ outline:3px solid var(--teal); outline-offset:2px; border-radius:4px; }

/* ---------- Header ---------- */
.site-header{
  position:sticky; top:0; z-index:50;
  background:rgba(250,252,254,.92);
  backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line);
}
.header-inner{
  display:flex; align-items:center; justify-content:space-between;
  height:72px; gap:24px;
}
.logo{ display:flex; align-items:center; gap:12px; }
.logo svg{ width:42px; height:42px; flex:none; }
.logo-name{ display:flex; flex-direction:column; line-height:1.25; }
.logo-name b{ font-family:var(--serif); font-size:19px; letter-spacing:.06em; color:var(--ink); }
.logo-name span{ font-size:10.5px; letter-spacing:.22em; color:var(--ink-soft); font-family:var(--mono); text-transform:uppercase; }

.main-nav{ display:flex; align-items:center; gap:6px; }
.main-nav a{
  padding:8px 16px; border-radius:999px;
  font-size:15px; color:var(--ink-soft);
  transition:color .2s, background .2s;
}
.main-nav a:hover{ color:var(--blue); background:var(--mist); }
.main-nav a[aria-current="page"]{ color:var(--blue); font-weight:600; background:var(--mist); }

.btn{
  display:inline-flex; align-items:center; justify-content:center; gap:8px;
  padding:11px 24px; border-radius:999px; border:1.5px solid transparent;
  font-size:15px; font-weight:600; cursor:pointer;
  transition:transform .18s, box-shadow .18s, background .18s, color .18s;
}
.btn-primary{ background:var(--blue); color:#fff; box-shadow:0 6px 18px rgba(22,84,143,.28); }
.btn-primary:hover{ background:var(--blue-deep); transform:translateY(-1px); }
.btn-ghost{ border-color:var(--line); color:var(--blue); background:var(--white); }
.btn-ghost:hover{ border-color:var(--blue); }
.btn-light{ background:#fff; color:var(--blue); }
.btn-light:hover{ transform:translateY(-1px); }

.nav-toggle{ display:none; background:none; border:none; cursor:pointer; padding:8px; }
.nav-toggle span{ display:block; width:22px; height:2px; background:var(--ink); margin:5px 0; border-radius:2px; }

/* ---------- Breath line (signature) ---------- */
.breath{
  display:block; width:100%; height:64px; overflow:visible;
}
.breath path{
  fill:none; stroke:var(--teal); stroke-width:2; stroke-linecap:round;
  opacity:.65;
}
@keyframes breathe{
  0%,100%{ transform:scaleY(.55); opacity:.45; }
  50%    { transform:scaleY(1);   opacity:.85; }
}
.breath path{ transform-origin:center; animation:breathe 6.5s ease-in-out infinite; }

/* small inline pulse divider */
.pulse-divider{
  display:flex; align-items:center; gap:14px; margin:0 0 14px;
}
.pulse-divider svg{ width:64px; height:18px; flex:none; }
.pulse-divider svg path{ fill:none; stroke:var(--teal); stroke-width:2; stroke-linecap:round; }
.eyebrow{
  font-family:var(--mono); font-size:12.5px; letter-spacing:.28em;
  color:var(--blue); text-transform:uppercase;
}

/* ---------- Hero ---------- */
.hero{
  background:
    radial-gradient(900px 480px at 85% -10%, rgba(47,168,160,.10), transparent 60%),
    linear-gradient(180deg, var(--mist) 0%, var(--paper) 78%);
  border-bottom:1px solid var(--line);
  overflow:hidden;
}
.hero-inner{
  display:grid; grid-template-columns:1.05fr .95fr; gap:56px;
  align-items:center; padding:72px 0 64px;
}
.hero h1{
  font-family:var(--serif); font-weight:700;
  font-size:clamp(30px, 4.2vw, 46px);
  line-height:1.35; letter-spacing:.02em;
  margin:14px 0 18px;
}
.hero h1 em{ font-style:normal; color:var(--blue); }
.hero-sub{ color:var(--ink-soft); font-size:16.5px; max-width:34em; }
.hero-cta{ display:flex; gap:14px; margin:30px 0 34px; flex-wrap:wrap; }

.spec-chips{ display:flex; gap:10px; flex-wrap:wrap; }
.chip{
  font-family:var(--mono); font-size:12.5px; color:var(--blue-deep);
  background:var(--white); border:1px solid var(--line);
  padding:6px 13px; border-radius:999px;
}
.chip b{ color:var(--teal-deep); }

.hero-visual{ position:relative; }
.hero-photo{
  border-radius:20px; overflow:hidden; box-shadow:var(--shadow);
  border:1px solid var(--line);
}
.hero-photo img{ width:100%; height:420px; object-fit:cover; }
.float-card{
  position:absolute; left:-26px; bottom:28px;
  background:var(--white); border:1px solid var(--line); border-radius:14px;
  box-shadow:var(--shadow); padding:14px 18px;
  display:flex; align-items:center; gap:14px;
}
.float-card .spo2{
  font-family:var(--mono); font-size:26px; font-weight:600; color:var(--teal-deep);
  line-height:1;
}
.float-card small{ display:block; font-size:12px; color:var(--ink-soft); margin-top:4px; letter-spacing:.08em; }
.float-card svg{ width:70px; height:26px; }
.float-card svg path{ fill:none; stroke:var(--teal); stroke-width:2; stroke-linecap:round; }

/* ---------- Sections ---------- */
.section{ padding:78px 0; }
.section.tint{ background:var(--mist); border-block:1px solid var(--line); }
.section-head{ max-width:640px; margin-bottom:44px; }
.section-head h2{
  font-family:var(--serif); font-size:clamp(24px,3vw,32px);
  line-height:1.4; letter-spacing:.02em;
}
.section-head p{ color:var(--ink-soft); margin-top:10px; }

/* device chooser cards */
.grid-3{ display:grid; grid-template-columns:repeat(3,1fr); gap:22px; }
.card{
  background:var(--white); border:1px solid var(--line); border-radius:var(--radius);
  padding:30px 28px; transition:transform .2s, box-shadow .2s;
}
.card:hover{ transform:translateY(-4px); box-shadow:var(--shadow); }
.card-tag{
  display:inline-block; font-family:var(--mono); font-size:11.5px; letter-spacing:.18em;
  color:var(--blue); background:var(--mist); border-radius:999px; padding:4px 12px;
  margin-bottom:16px;
}
.card h3{ font-size:19px; margin-bottom:6px; }
.card .fit{ font-size:14px; color:var(--teal-deep); font-weight:600; margin-bottom:10px; }
.card p{ font-size:14.5px; color:var(--ink-soft); }
.card ul{ margin-top:12px; }
.card li{
  font-size:14px; color:var(--ink-soft); padding-left:18px; position:relative; margin:6px 0;
}
.card li::before{
  content:""; position:absolute; left:0; top:.62em; width:8px; height:8px;
  border-radius:50%; background:var(--teal); opacity:.7;
}

/* product line strip */
.product-strip{ display:grid; grid-template-columns:repeat(5,1fr); gap:16px; }
.product-item{
  background:var(--white); border:1px solid var(--line); border-radius:var(--radius);
  padding:22px 18px; text-align:center;
}
.product-item .zh{ font-weight:600; font-size:15.5px; }
.product-item .en{ font-family:var(--mono); font-size:10.5px; color:var(--ink-soft); letter-spacing:.1em; margin-top:4px; display:block; }
.product-item svg{ width:34px; height:34px; margin:0 auto 12px; display:block; stroke:var(--blue); }

/* team */
.team-grid{ display:grid; grid-template-columns:1fr 1fr; gap:48px; align-items:center; }
.team-photo{ border-radius:18px; overflow:hidden; border:1px solid var(--line); box-shadow:var(--shadow); }
.team-photo img{ width:100%; height:400px; object-fit:cover; }
.role-list{ margin-top:26px; display:grid; gap:16px; }
.role{
  display:flex; gap:16px; align-items:flex-start;
  background:var(--white); border:1px solid var(--line); border-radius:12px; padding:16px 18px;
}
.role-badge{
  flex:none; width:44px; height:44px; border-radius:12px;
  background:var(--mist); color:var(--blue); font-family:var(--serif); font-weight:700;
  display:flex; align-items:center; justify-content:center; font-size:18px;
}
.role b{ display:block; font-size:15.5px; }
.role p{ font-size:13.5px; color:var(--ink-soft); margin-top:2px; }

.stat-row{ display:flex; gap:34px; margin-top:30px; flex-wrap:wrap; }
.stat b{ font-family:var(--mono); font-size:30px; color:var(--blue); font-weight:600; }
.stat span{ display:block; font-size:13px; color:var(--ink-soft); margin-top:2px; }

/* process (real sequence → numbers are meaningful) */
.process{ display:grid; grid-template-columns:repeat(4,1fr); gap:18px; counter-reset:step; }
.step{
  background:var(--white); border:1px solid var(--line); border-radius:var(--radius);
  padding:26px 22px; position:relative;
}
.step::before{
  counter-increment:step; content:"0" counter(step);
  font-family:var(--mono); font-size:13px; color:var(--teal-deep); letter-spacing:.15em;
}
.step h3{ font-size:16.5px; margin:10px 0 6px; }
.step p{ font-size:13.5px; color:var(--ink-soft); }

/* rent vs buy */
.rb-grid{ display:grid; grid-template-columns:1fr 1fr; gap:22px; }
.rb{ background:var(--white); border:1px solid var(--line); border-radius:var(--radius); padding:30px; }
.rb.highlight{ border-color:var(--blue); box-shadow:var(--shadow); }
.rb h3{ font-family:var(--serif); font-size:20px; }
.rb .for{ font-size:13.5px; color:var(--teal-deep); font-weight:600; margin:4px 0 14px; }
.rb li{ padding-left:20px; position:relative; margin:8px 0; font-size:14.5px; color:var(--ink-soft); }
.rb li::before{ content:"✓"; position:absolute; left:0; color:var(--blue); font-weight:700; }

/* brand wall */
.brand-grid{ display:grid; grid-template-columns:1fr 1fr; gap:48px; align-items:center; }
.brand-photo{ border-radius:18px; overflow:hidden; border:1px solid var(--line); box-shadow:var(--shadow); }
.brand-photo img{ width:100%; height:380px; object-fit:cover; }
.brand-names{ display:flex; flex-wrap:wrap; gap:10px; margin-top:20px; }
.brand-names span{
  font-size:13.5px; color:var(--ink-soft); background:var(--white);
  border:1px solid var(--line); border-radius:999px; padding:6px 15px;
}

/* assurance bar */
.assure{ display:grid; grid-template-columns:repeat(4,1fr); gap:18px; }
.assure div{
  background:rgba(255,255,255,.10); border:1px solid rgba(255,255,255,.22);
  border-radius:12px; padding:20px 22px; color:#fff;
}
.assure b{ display:block; font-size:16px; margin-bottom:4px; }
.assure p{ font-size:13px; opacity:.85; }

/* CTA band */
.cta-band{
  background:linear-gradient(120deg, var(--blue-deep), var(--blue) 60%, #1E6FB4);
  color:#fff; border-radius:22px; padding:56px 56px;
  display:flex; align-items:center; justify-content:space-between; gap:32px;
  position:relative; overflow:hidden;
}
.cta-band::after{
  content:""; position:absolute; right:-60px; top:-60px; width:280px; height:280px;
  border-radius:50%; background:rgba(255,255,255,.07);
}
.cta-band h2{ font-family:var(--serif); font-size:clamp(22px,2.6vw,30px); line-height:1.45; }
.cta-band p{ opacity:.88; margin-top:8px; font-size:15px; }

/* ---------- Footer ---------- */
.site-footer{
  background:var(--ink); color:#B9C7D3; margin-top:90px;
  font-size:14px;
}
.footer-inner{
  display:grid; grid-template-columns:1.4fr 1fr 1fr; gap:48px;
  padding:56px 0 40px;
}
.footer-inner h4{ color:#fff; font-size:15px; margin-bottom:14px; font-weight:600; }
.footer-inner a{ display:block; margin:8px 0; opacity:.85; }
.footer-inner a:hover{ color:#fff; opacity:1; }
.footer-logo{ display:flex; align-items:center; gap:10px; margin-bottom:16px; }
.footer-logo svg{ width:36px; height:36px; }
.footer-logo b{ font-family:var(--serif); color:#fff; font-size:17px; letter-spacing:.06em; }
.footer-note{ font-size:12.5px; opacity:.65; line-height:1.9; margin-top:14px; }
.footer-bottom{
  border-top:1px solid rgba(255,255,255,.12);
  padding:18px 0 22px; font-size:12.5px; opacity:.6;
  display:flex; justify-content:space-between; flex-wrap:wrap; gap:8px;
}

/* ============ FAQ page ============ */
.page-hero{
  background:linear-gradient(180deg, var(--mist) 0%, var(--paper) 100%);
  border-bottom:1px solid var(--line);
  padding:60px 0 48px;
}
.page-hero h1{ font-family:var(--serif); font-size:clamp(26px,3.4vw,38px); margin-top:12px; }
.page-hero p{ color:var(--ink-soft); margin-top:10px; max-width:40em; }

.faq-layout{ display:grid; grid-template-columns:240px 1fr; gap:48px; padding:56px 0; }
.faq-nav{ position:sticky; top:96px; align-self:start; }
.faq-nav a{
  display:block; padding:10px 16px; border-left:2.5px solid var(--line);
  color:var(--ink-soft); font-size:14.5px; transition:all .18s;
}
.faq-nav a:hover, .faq-nav a.active{ color:var(--blue); border-left-color:var(--blue); background:var(--mist); }

.faq-group{ margin-bottom:52px; scroll-margin-top:100px; }
.faq-group > h2{
  font-family:var(--serif); font-size:22px; margin-bottom:8px;
}
.faq-group > .group-sub{ font-size:14px; color:var(--ink-soft); margin-bottom:20px; }

details.faq{
  background:var(--white); border:1px solid var(--line); border-radius:12px;
  margin-bottom:12px; overflow:hidden; transition:box-shadow .2s;
}
details.faq[open]{ box-shadow:var(--shadow); border-color:var(--mist-2); }
details.faq summary{
  cursor:pointer; list-style:none; padding:18px 52px 18px 22px;
  font-weight:600; font-size:15.5px; position:relative; color:var(--ink);
}
details.faq summary::-webkit-details-marker{ display:none; }
details.faq summary::after{
  content:"＋"; position:absolute; right:20px; top:50%; transform:translateY(-50%);
  color:var(--blue); font-size:18px; transition:transform .2s;
}
details.faq[open] summary::after{ content:"－"; }
.faq-body{ padding:0 22px 20px; color:var(--ink-soft); font-size:14.5px; }
.faq-body p{ margin-bottom:10px; }
.faq-body ul{ margin:6px 0 10px; }
.faq-body li{ padding-left:18px; position:relative; margin:6px 0; }
.faq-body li::before{
  content:""; position:absolute; left:0; top:.66em; width:7px; height:7px;
  border-radius:50%; background:var(--teal); opacity:.65;
}
.faq-body b{ color:var(--ink); }
.faq-body .warn{
  background:#FDF3F0; border:1px solid #F3D5CB; color:#8C3B25;
  border-radius:10px; padding:12px 16px; font-size:13.5px; margin-top:8px;
}
.faq-body .tip{
  background:var(--mist); border:1px solid var(--mist-2); color:var(--blue-deep);
  border-radius:10px; padding:12px 16px; font-size:13.5px; margin-top:8px;
}

/* ============ Articles ============ */
.article-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:24px; padding-bottom:20px; }
.article-card{
  background:var(--white); border:1px solid var(--line); border-radius:var(--radius);
  overflow:hidden; display:flex; flex-direction:column;
  transition:transform .2s, box-shadow .2s;
}
.article-card:hover{ transform:translateY(-4px); box-shadow:var(--shadow); }
.article-card .thumb{ height:170px; overflow:hidden; background:var(--mist); position:relative; }
.article-card .thumb img{ width:100%; height:100%; object-fit:cover; }
.thumb-abstract{
  width:100%; height:100%;
  display:flex; align-items:center; justify-content:center;
}
.thumb-abstract svg{ width:100%; height:70%; }
.article-card .body{ padding:20px 22px 24px; display:flex; flex-direction:column; flex:1; }
.article-meta{
  display:flex; gap:12px; align-items:center; font-size:12px; margin-bottom:10px;
  font-family:var(--mono); color:var(--ink-soft);
}
.article-meta .cat{ color:var(--teal-deep); background:rgba(47,168,160,.10); padding:2px 10px; border-radius:999px; }
.article-card h3{ font-size:16.5px; line-height:1.55; margin-bottom:8px; }
.article-card h3 a:hover{ color:var(--blue); }
.article-card .excerpt{ font-size:13.5px; color:var(--ink-soft); flex:1; }
.article-card .more{ margin-top:14px; font-size:13.5px; color:var(--blue); font-weight:600; }

/* ============ Article detail ============ */
.article-page{ display:grid; grid-template-columns:1fr 300px; gap:56px; padding:56px 0; }
.article-main{ max-width:720px; }
.article-main h1{
  font-family:var(--serif); font-size:clamp(24px,3vw,34px); line-height:1.5; margin:14px 0 16px;
}
.article-main .lede{ font-size:16.5px; color:var(--ink-soft); border-left:3px solid var(--teal); padding-left:18px; margin:20px 0 30px; }
.article-main h2{ font-family:var(--serif); font-size:22px; margin:40px 0 14px; scroll-margin-top:100px; }
.article-main h3{ font-size:17px; margin:26px 0 10px; }
.article-main p{ margin-bottom:14px; color:#2A3B4A; }
.article-main ul, .article-main ol{ margin:0 0 16px 2px; }
.article-main ul li{ padding-left:20px; position:relative; margin:7px 0; color:#2A3B4A; }
.article-main ul li::before{
  content:""; position:absolute; left:0; top:.68em; width:8px; height:8px;
  border-radius:50%; background:var(--teal); opacity:.65;
}
.article-main ol{ list-style:decimal; margin-left:22px; }
.article-main ol li{ margin:7px 0; color:#2A3B4A; padding-left:4px; }

.compare-table{ width:100%; border-collapse:collapse; margin:18px 0 26px; font-size:14px; }
.compare-table th{
  background:var(--mist); color:var(--blue-deep); text-align:left;
  padding:12px 14px; border:1px solid var(--line); font-size:13.5px;
}
.compare-table td{ padding:12px 14px; border:1px solid var(--line); color:var(--ink-soft); vertical-align:top; }
.compare-table td:first-child{ font-weight:600; color:var(--ink); white-space:nowrap; }

.callout{
  background:var(--mist); border:1px solid var(--mist-2); border-radius:12px;
  padding:18px 22px; margin:22px 0; font-size:14.5px; color:var(--blue-deep);
}
.callout b{ display:block; margin-bottom:4px; }
.callout.warn{ background:#FDF3F0; border-color:#F3D5CB; color:#8C3B25; }

.review-note{
  display:flex; gap:14px; align-items:center; margin-top:44px;
  background:var(--white); border:1px solid var(--line); border-radius:12px; padding:16px 20px;
}
.review-note .avatar{
  flex:none; width:44px; height:44px; border-radius:50%;
  background:var(--mist); color:var(--blue); font-family:var(--serif); font-weight:700;
  display:flex; align-items:center; justify-content:center;
}
.review-note p{ font-size:13px; color:var(--ink-soft); margin:0; }
.review-note b{ font-size:14px; color:var(--ink); }

.article-aside{ align-self:start; position:sticky; top:96px; display:grid; gap:26px; }
.aside-box{ background:var(--white); border:1px solid var(--line); border-radius:var(--radius); padding:24px; }
.aside-box h4{ font-size:15px; margin-bottom:14px; }
.aside-box .toc a{ display:block; font-size:13.5px; color:var(--ink-soft); padding:6px 0 6px 14px; border-left:2px solid var(--line); }
.aside-box .toc a:hover{ color:var(--blue); border-left-color:var(--blue); }
.related a{ display:block; font-size:14px; line-height:1.55; padding:10px 0; border-bottom:1px dashed var(--line); }
.related a:last-child{ border-bottom:none; }
.related a:hover{ color:var(--blue); }
.aside-cta{ background:linear-gradient(140deg,var(--blue-deep),var(--blue)); color:#fff; border:none; }
.aside-cta p{ font-size:13.5px; opacity:.88; margin:8px 0 16px; }
.aside-cta h4{ color:#fff; font-family:var(--serif); font-size:17px; }

.breadcrumb{ font-size:13px; color:var(--ink-soft); font-family:var(--mono); }
.breadcrumb a:hover{ color:var(--blue); }
.breadcrumb .sep{ margin:0 8px; opacity:.5; }

/* ---------- Reveal on scroll ---------- */
.reveal{ opacity:0; transform:translateY(18px); transition:opacity .6s ease, transform .6s ease; }
.reveal.in{ opacity:1; transform:none; }

/* ---------- Responsive ---------- */
@media (max-width: 980px){
  .hero-inner{ grid-template-columns:1fr; padding:52px 0 48px; gap:36px; }
  .hero-photo img{ height:320px; }
  .grid-3{ grid-template-columns:1fr; }
  .product-strip{ grid-template-columns:repeat(2,1fr); }
  .team-grid,.brand-grid,.rb-grid{ grid-template-columns:1fr; gap:30px; }
  .process{ grid-template-columns:repeat(2,1fr); }
  .assure{ grid-template-columns:repeat(2,1fr); }
  .cta-band{ flex-direction:column; text-align:center; padding:44px 28px; }
  .faq-layout{ grid-template-columns:1fr; gap:12px; }
  .faq-nav{ position:static; display:flex; overflow-x:auto; gap:8px; padding-bottom:12px; }
  .faq-nav a{ border-left:none; border:1px solid var(--line); border-radius:999px; white-space:nowrap; padding:8px 16px; }
  .article-grid{ grid-template-columns:1fr; }
  .article-page{ grid-template-columns:1fr; }
  .article-aside{ position:static; }
  .footer-inner{ grid-template-columns:1fr; gap:30px; }

  .main-nav{
    display:none; position:absolute; top:72px; left:0; right:0;
    background:var(--paper); border-bottom:1px solid var(--line);
    flex-direction:column; align-items:stretch; padding:12px 24px 18px; gap:4px;
  }
  .main-nav.open{ display:flex; }
  .main-nav a{ border-radius:10px; padding:12px 16px; }
  .nav-toggle{ display:block; }
  .header-cta{ display:none; }
  .float-card{ left:12px; bottom:14px; }
}