:root{
  --red:#D83A2E;
  --red-deep:#B02A20;
  --red-soft:#FAE7E4;
  --bg:#F5F3F3;
  --paper:#FFFFFF;
  --ink:#1D1B1A;
  --ink-2:#4A4644;
  --muted:#8B827D;
  --line:#E4DDD9;
  --line-2:#CFC6C1;
  --dark:#191716;
  --sans:"Inter","Helvetica Neue",-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --serif:"Noto Serif SC","Source Han Serif SC","Songti SC","STSong",Georgia,serif;
  --wrap:min(1200px,92vw);
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  margin:0;background:var(--bg);color:var(--ink);
  font-family:var(--sans);font-size:16px;line-height:1.85;
  letter-spacing:.01em;text-rendering:optimizeLegibility;
  -webkit-font-smoothing:antialiased;
}
img,svg{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
::selection{background:var(--red);color:#fff}
.wrap{width:var(--wrap);margin:0 auto}
.skip{position:absolute;left:-9999px;top:0;background:var(--red);color:#fff;padding:10px 16px;z-index:99}
.skip:focus{left:12px;top:12px}

/* ---------- top bar ---------- */
.topbar{border-bottom:1px solid var(--line);background:var(--bg)}
.topbar .wrap{display:flex;justify-content:space-between;align-items:center;height:44px;font-size:12.5px;color:var(--muted);letter-spacing:.04em}
.topbar a.tel{color:var(--ink-2);font-weight:600;letter-spacing:.06em}
.topbar a.tel:hover{color:var(--red)}
.topbar .right{display:flex;align-items:center;gap:18px}
.lang-btn{
  border:1px solid var(--line-2);background:transparent;color:var(--ink-2);
  font:inherit;font-size:11.5px;letter-spacing:.12em;padding:3px 9px;border-radius:2px;cursor:pointer;
  transition:.2s;
}
.lang-btn:hover{border-color:var(--red);color:var(--red)}

/* ---------- nav ---------- */
.nav{position:sticky;top:0;z-index:40;background:rgba(245,243,243,.92);backdrop-filter:saturate(140%) blur(10px);border-bottom:1px solid var(--line)}
.nav .wrap{display:flex;align-items:center;justify-content:space-between;height:76px;gap:16px}
.brand{display:flex;align-items:center;gap:12px;flex-shrink:0}
.brand .mark{width:34px;height:34px;background:var(--red);position:relative;flex-shrink:0}
.brand .mark::before,.brand .mark::after{content:"";position:absolute;background:#fff}
.brand .mark::before{left:7px;right:7px;top:11px;height:2px}
.brand .mark::after{left:7px;right:7px;top:19px;height:2px;opacity:.55}
.brand b{font-family:var(--serif);font-size:19px;font-weight:600;letter-spacing:.08em;line-height:1.2;display:block}
.brand span{display:block;font-size:9px;letter-spacing:.15em;color:var(--muted);text-transform:uppercase;margin-top:2px}
.menu{display:flex;align-items:center;gap:22px}
.menu a{font-size:14.5px;color:var(--ink-2);position:relative;padding:6px 0;letter-spacing:.03em}
.menu a:hover{color:var(--red)}
.menu a.on{color:var(--ink);font-weight:600}
.menu a.on::after{content:"";position:absolute;left:0;right:0;bottom:-2px;height:2px;background:var(--red)}
.nav-tel{font-size:13.5px;font-weight:700;color:var(--ink);border-left:1px solid var(--line-2);padding-left:26px;letter-spacing:.04em;white-space:nowrap}
.nav-tel small{display:block;font-size:10px;color:var(--muted);font-weight:400;letter-spacing:.14em}
.burger{display:none;width:42px;height:42px;border:1px solid var(--line-2);background:none;cursor:pointer;position:relative}
.burger i{position:absolute;left:11px;right:11px;height:1.5px;background:var(--ink);transition:.25s}
.burger i:nth-child(1){top:15px}.burger i:nth-child(2){top:20px}.burger i:nth-child(3){top:25px}

/* ---------- hero ---------- */
.hero{position:relative;overflow:hidden;border-bottom:1px solid var(--line)}
.hero::before{
  content:"";position:absolute;right:-18vw;top:-24vw;width:62vw;height:62vw;border-radius:50%;
  background:radial-gradient(circle at 50% 50%,rgba(216,58,46,.14),rgba(216,58,46,0) 62%);
  pointer-events:none;
}
.hero .wrap{position:relative;padding:12px 0 6px;display:grid;grid-template-columns:1.12fr .88fr;gap:64px;align-items:center}
.eyebrow{display:flex;align-items:center;gap:12px;font-size:12px;letter-spacing:.2em;color:var(--red);text-transform:uppercase;margin-bottom:6px}
.eyebrow::before{content:"";width:34px;height:1px;background:var(--red)}
.hero h1{
  font-family:var(--serif);font-weight:600;font-size:clamp(32px,4vw,46px);line-height:1.25;
  letter-spacing:.02em;margin:0 0 12px;
}
.hero h1 em{font-style:normal;color:var(--red)}
.hero p.lead{font-size:16px;line-height:1.75;color:var(--ink-2);max-width:34em;margin:0 0 10px}
.hero p.lead .en{display:block;font-size:13.5px;color:var(--muted);line-height:1.8;margin-top:10px;letter-spacing:.02em}
.btn-row{display:flex;gap:14px;flex-wrap:wrap}
.btn{display:inline-flex;align-items:center;gap:10px;padding:12px 24px;font-size:14.5px;letter-spacing:.05em;border:1px solid transparent;transition:.22s}
.btn-primary{background:var(--red);color:#fff}
.btn-primary:hover{background:var(--red-deep);transform:translateY(-1px)}
.btn-ghost{border-color:var(--line-2);color:var(--ink)}
.btn-ghost:hover{border-color:var(--ink);background:rgba(255,255,255,.6)}
.btn svg{width:16px;height:16px}

.hero-stats{display:grid;grid-template-columns:repeat(4,1fr);gap:1px;background:var(--line);border:1px solid var(--line);margin-top:10px}
.hero-stats div{background:var(--bg);padding:9px 16px}
.hero-stats b{display:block;font-family:var(--serif);font-size:24px;font-weight:600;letter-spacing:.01em;line-height:1.2;white-space:nowrap}
.hero-stats b i{font-style:normal;font-size:13px;color:var(--muted);margin-left:4px;font-family:var(--sans)}
.hero-stats span{display:block;font-size:11px;color:var(--muted);letter-spacing:.08em;margin-top:3px;text-transform:uppercase}

.hero-art{position:relative;margin:0}
.hero-art .plate-figure{display:block;width:auto;max-height:250px;margin:0 auto}
.hero-art figcaption{font-size:12px;color:var(--muted);letter-spacing:.06em;margin-top:12px;border-top:1px solid var(--line);padding-top:10px;line-height:1.7;max-width:420px}

/* ---------- generic sections ---------- */
section{padding:104px 0}
section.tight{padding:76px 0}
section.slim{padding:54px 0}
.bg-paper{background:var(--paper)}
.bg-dark{background:var(--dark);color:#EFEAE7}
.bg-dark .muted{color:#9E9490}
.section-head{display:grid;grid-template-columns:.34fr .66fr;gap:40px;align-items:end;margin-bottom:56px}
.section-head .no{font-size:12px;letter-spacing:.18em;color:var(--red);display:flex;align-items:center;gap:10px}
.section-head .no::after{content:"";flex:1;height:1px;background:var(--line-2);max-width:80px}
.section-head h2{font-family:var(--serif);font-size:clamp(28px,3.4vw,40px);font-weight:600;line-height:1.4;letter-spacing:.02em;margin:0}
.section-head .sub{font-size:14px;color:var(--muted);margin-top:14px;letter-spacing:.04em;line-height:1.9}
.bg-dark .section-head .no::after{background:#3A3432}
.bg-dark .section-head h2{color:#F3EEEA}

/* ---------- product line cards ---------- */
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--line);border:1px solid var(--line)}
.card{background:var(--paper);padding:38px 34px 34px;position:relative;transition:.25s;min-height:100%}
.card:hover{background:#fff;box-shadow:0 18px 40px -28px rgba(29,27,26,.35);z-index:2}
.card .num{font-size:11px;letter-spacing:.16em;color:var(--muted)}
.card h3{font-family:var(--serif);font-size:21px;font-weight:600;margin:16px 0 4px;letter-spacing:.03em;line-height:1.5}
.card h3 .en{display:block;font-family:var(--sans);font-size:11px;letter-spacing:.14em;color:var(--muted);font-weight:400;text-transform:uppercase;margin-top:6px}
.card p{font-size:14px;color:var(--ink-2);line-height:1.95;margin:16px 0 0}
.card .more{margin-top:22px;font-size:12.5px;letter-spacing:.1em;color:var(--red);display:inline-flex;align-items:center;gap:8px}
.card .more::after{content:"→";transition:.2s}
.card:hover .more::after{transform:translateX(4px)}
.card .ico{width:40px;height:40px;color:var(--red);margin-bottom:6px}

/* ---------- series list ---------- */
.series{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--line);border:1px solid var(--line)}
.series a{background:var(--paper);padding:30px 30px 28px;display:flex;flex-direction:column;gap:8px;transition:.22s;position:relative}
.series a:hover{background:#FFFCFB}
.series a:hover .s-name{color:var(--red)}
.series .s-no{font-size:11px;letter-spacing:.16em;color:var(--muted)}
.s-name{font-family:var(--serif);font-size:18px;font-weight:600;letter-spacing:.03em;transition:.2s;line-height:1.5}
.s-en{font-size:11px;letter-spacing:.1em;color:var(--muted);text-transform:uppercase}
.s-spec{font-size:12.5px;color:var(--ink-2);border-top:1px solid var(--line);padding-top:10px;margin-top:8px;letter-spacing:.02em}
.s-spec b{font-weight:600}

/* ---------- applications band ---------- */
.apps{display:grid;grid-template-columns:repeat(3,1fr);gap:0;border-top:1px solid #322C2A}
.apps div{border-bottom:1px solid #322C2A;border-right:1px solid #322C2A;padding:30px 28px}
.apps div:nth-child(3n){border-right:none}
.apps h4{font-family:var(--serif);font-size:17px;font-weight:500;margin:0 0 6px;letter-spacing:.04em;color:#F0EAE6}
.apps span{font-size:12px;color:#8E8480;letter-spacing:.08em;line-height:1.8;display:block}

/* ---------- tables ---------- */
.table-wrap{overflow-x:auto;border:1px solid var(--line);background:var(--paper)}
table.grades{width:100%;border-collapse:collapse;font-size:13.5px;min-width:720px}
table.grades th{
  background:#EFEAE7;color:var(--ink);font-weight:600;text-align:left;
  padding:14px 18px;font-size:12px;letter-spacing:.08em;border-bottom:1px solid var(--line-2);white-space:nowrap;
}
table.grades td{padding:13px 18px;border-bottom:1px solid var(--line);vertical-align:top;line-height:1.7}
table.grades tr:last-child td{border-bottom:none}
table.grades tbody tr:hover{background:#FBF7F6}
table.grades td.g{font-weight:600;font-family:var(--sans);letter-spacing:.02em;color:var(--ink)}
table.grades td.std,table.grades td.cond{color:var(--ink-2);font-size:12.5px}
.num-cell{font-variant-numeric:tabular-nums;white-space:nowrap;color:var(--ink-2)}

/* ---------- prosaic blocks ---------- */
.split{display:grid;grid-template-columns:.92fr 1.08fr;gap:72px;align-items:start}
.split h2{font-family:var(--serif);font-size:clamp(26px,3vw,36px);font-weight:600;line-height:1.45;margin:0 0 22px;letter-spacing:.02em}
.prose p{font-size:15.5px;line-height:2.1;color:var(--ink-2);margin:0 0 18px}
.prose p b{color:var(--ink);font-weight:600}
.prose ul{margin:0;padding:0;list-style:none}
.prose ul li{position:relative;padding-left:20px;font-size:15px;line-height:2;color:var(--ink-2);margin-bottom:10px}
.prose ul li::before{content:"";position:absolute;left:0;top:14px;width:6px;height:1.5px;background:var(--red)}
.note{border-left:2px solid var(--red);padding:4px 0 4px 20px;font-size:14px;color:var(--ink-2);line-height:2;margin:26px 0 0}
.facts{display:grid;grid-template-columns:1fr 1fr;gap:1px;background:var(--line);border:1px solid var(--line);margin-top:30px}
.facts div{background:var(--paper);padding:20px 22px}
.facts span{display:block;font-size:11px;letter-spacing:.12em;color:var(--muted);text-transform:uppercase}
.facts b{display:block;font-size:14.5px;margin-top:6px;font-weight:600;line-height:1.6}

/* ---------- breadcrumb ---------- */
.crumb{border-bottom:1px solid var(--line);background:var(--bg)}
.crumb .wrap{display:flex;align-items:center;gap:10px;font-size:12px;color:var(--muted);padding:16px 0;letter-spacing:.04em;flex-wrap:wrap}
.crumb a:hover{color:var(--red)}
.crumb i{font-style:normal;color:var(--line-2)}

/* ---------- page hero ---------- */
.phero{padding:64px 0 56px;border-bottom:1px solid var(--line);position:relative;overflow:hidden}
.phero::after{content:"";position:absolute;right:-10vw;top:-16vw;width:44vw;height:44vw;border-radius:50%;background:radial-gradient(circle,rgba(216,58,46,.09),transparent 65%);pointer-events:none}
.phero h1{font-family:var(--serif);font-size:clamp(32px,4.2vw,52px);font-weight:600;margin:0 0 10px;letter-spacing:.02em;line-height:1.35}
.phero .h1en{font-size:12px;letter-spacing:.24em;color:var(--muted);text-transform:uppercase;margin-bottom:26px}
.phero p{max-width:46em;font-size:16px;line-height:2;color:var(--ink-2);margin:0}
.meta-strip{display:flex;flex-wrap:wrap;gap:0;margin-top:34px;border-top:1px solid var(--line)}
.meta-strip div{padding:16px 28px 0 0;margin-right:28px;border-right:1px solid var(--line)}
.meta-strip div:last-child{border-right:none;margin-right:0}
.meta-strip span{display:block;font-size:10.5px;letter-spacing:.14em;color:var(--muted);text-transform:uppercase}
.meta-strip b{display:block;font-size:14px;margin-top:4px;font-weight:600;line-height:1.5}

/* ---------- chips / keywords ---------- */
.chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:20px}
.chips a,.chips span{
  font-size:12.5px;letter-spacing:.03em;border:1px solid var(--line-2);padding:5px 12px;color:var(--ink-2);
  transition:.2s;background:transparent;line-height:1.6;
}
.chips a:hover{border-color:var(--red);color:var(--red);background:#fff}
.keywords{border-top:1px solid var(--line);margin-top:72px;padding-top:26px;display:grid;grid-template-columns:.24fr .76fr;gap:24px;align-items:start}
.keywords .k-label{font-size:11px;letter-spacing:.18em;color:var(--muted);text-transform:uppercase;padding-top:7px}
.keywords .k-list{display:flex;flex-wrap:wrap;gap:10px 22px}
.keywords a{font-size:13.5px;color:var(--ink-2);border-bottom:1px solid var(--line-2);padding-bottom:2px;transition:.2s}
.keywords a:hover{color:var(--red);border-color:var(--red)}

/* ---------- cta ---------- */
.cta{background:var(--dark);color:#F1ECE9;padding:80px 0}
.cta .wrap{display:grid;grid-template-columns:1.2fr .8fr;gap:48px;align-items:center}
.cta h2{font-family:var(--serif);font-size:clamp(26px,3.2vw,38px);font-weight:600;margin:0 0 14px;line-height:1.45;letter-spacing:.02em}
.cta p{color:#A69C97;font-size:14.5px;line-height:1.95;margin:0;max-width:36em}
.cta .tel-block{text-align:right}
.cta .tel-block span{display:block;font-size:11px;letter-spacing:.2em;color:#8E8480;text-transform:uppercase}
.cta .tel-block a{font-family:var(--serif);font-size:clamp(26px,3.4vw,40px);letter-spacing:.04em;color:#fff;display:block;margin-top:8px;line-height:1.2}
.cta .tel-block a:hover{color:var(--red)}
.cta .tel-block small{display:block;font-size:12px;color:#8E8480;margin-top:12px;letter-spacing:.06em}

/* ---------- footer ---------- */
footer{background:#111010;color:#9C928E;padding:70px 0 30px;font-size:13px}
footer .cols{display:grid;grid-template-columns:1.6fr 1fr 1fr 1fr;gap:44px;padding-bottom:52px;border-bottom:1px solid #282322}
footer h5{font-size:11px;letter-spacing:.16em;color:#D9D1CD;margin:0 0 18px;text-transform:uppercase;font-weight:600}
footer a{color:#9C928E;line-height:2.2;display:block;font-size:13px}
footer a:hover{color:#fff}
footer .brandline{font-family:var(--serif);font-size:19px;color:#EFE8E4;letter-spacing:.08em;margin-bottom:14px}
footer .brandline span{display:block;font-family:var(--sans);font-size:9.5px;letter-spacing:.22em;color:#7A716E;margin-top:5px}
footer p{margin:0;line-height:2;font-size:12.5px;color:#7A716E}
footer .bottom{display:flex;justify-content:space-between;gap:20px;padding-top:24px;font-size:11.5px;color:#6E6562;flex-wrap:wrap;letter-spacing:.03em}

/* ---------- misc ---------- */
.tagline-strip{border-top:1px solid var(--line);border-bottom:1px solid var(--line);overflow:hidden;background:var(--paper)}
.tagline-strip .wrap{display:flex;gap:56px;padding:18px 0;font-size:11.5px;letter-spacing:.14em;color:var(--muted);text-transform:uppercase;white-space:nowrap;overflow-x:auto}
.tagline-strip b{color:var(--red);font-weight:600}
.grade-index{display:grid;grid-template-columns:repeat(auto-fill,minmax(180px,1fr));gap:1px;background:var(--line);border:1px solid var(--line)}
.grade-index a{background:#fff;padding:16px 18px;display:block;transition:.18s}
.grade-index a:hover{background:var(--red-soft)}
.grade-index b{display:block;font-size:14px;font-weight:600;letter-spacing:.02em}
.grade-index span{display:block;font-size:11px;color:var(--muted);margin-top:3px;letter-spacing:.06em}
.filter-bar{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:28px;align-items:center}
.filter-bar input{
  flex:1;min-width:220px;border:1px solid var(--line-2);background:#fff;padding:12px 16px;font:inherit;font-size:14px;border-radius:0;outline:none;
}
.filter-bar input:focus{border-color:var(--red)}
.filter-bar button{
  border:1px solid var(--line-2);background:#fff;padding:10px 16px;font:inherit;font-size:12.5px;cursor:pointer;letter-spacing:.04em;transition:.2s;
}
.filter-bar button.on,.filter-bar button:hover{border-color:var(--red);color:var(--red)}
.empty-hint{font-size:13px;color:var(--muted);padding:20px 0}

/* ---------- responsive ---------- */
@media(max-width:1080px){
  .hero .wrap{grid-template-columns:1fr;gap:32px;padding:24px 0 20px}
  .hero-stats{grid-template-columns:repeat(2,1fr)}
  .hero-art{max-width:520px}
  .section-head{grid-template-columns:1fr;gap:16px}
  .split{grid-template-columns:1fr;gap:36px}
  .grid-3,.series,.apps{grid-template-columns:repeat(2,1fr)}
  .apps div:nth-child(3n){border-right:1px solid #322C2A}
  .apps div:nth-child(2n){border-right:none}
  .cta .wrap{grid-template-columns:1fr;gap:28px}
  .cta .tel-block{text-align:left}
  footer .cols{grid-template-columns:1fr 1fr}
}
@media(max-width:860px){
  .menu{
    position:fixed;inset:76px 0 auto;background:var(--bg);border-bottom:1px solid var(--line);
    flex-direction:column;align-items:flex-start;gap:0;padding:8px 4vw 22px;
    transform:translateY(-120%);transition:.32s cubic-bezier(.4,0,.2,1);max-height:calc(100vh - 76px);overflow:auto;
  }
  .menu.open{transform:translateY(0)}
  .menu a{width:100%;padding:14px 0;border-bottom:1px solid var(--line);font-size:15.5px}
  .menu a.on::after{display:none}
  .burger{display:block}
  .nav-tel{display:none}
  section{padding:68px 0}
  .grid-3,.series,.apps{grid-template-columns:1fr}
  .apps div{border-right:none}
  .hero-stats{grid-template-columns:1fr 1fr}
  .keywords{grid-template-columns:1fr;gap:12px}
  .facts{grid-template-columns:1fr}
  .meta-strip div{padding-right:20px;margin-right:20px;margin-bottom:8px}
  table.grades{font-size:12.5px}
  table.grades th,table.grades td{padding:11px 13px}
  footer .cols{grid-template-columns:1fr;gap:30px}
  .cta{padding:56px 0}
}
@media(max-width:520px){
  body{font-size:15px}
  .hero h1{font-size:32px}
  .hero p.lead{font-size:15.5px}
  .card{padding:28px 22px}
  .series a{padding:24px 22px}
  .topbar .wrap{font-size:11.5px;gap:10px}
  .topbar .hide-sm{display:none}
}

/* language switch */
html[data-lang="en"] .zh-only{display:none!important}
html[data-lang="en"] .en-only{display:block!important}
html[data-lang="en"] .en-only.inline{display:inline!important}
html[data-lang="zh"] .en-only{display:none!important}
.en-summary{
  font-size:13.5px;line-height:1.95;color:var(--muted);border-left:2px solid var(--line-2);
  padding:2px 0 2px 18px;margin:22px 0 0;max-width:52em;
}
.bi{display:block}
.bi .en{display:block;font-size:11px;letter-spacing:.12em;color:var(--muted);text-transform:uppercase;margin-top:4px;font-weight:400}