:root{
  --paper:#E3E6DB;
  --paper-dim:#CFD4C4;
  --panel:#DADFCF;
  --ink:#1B211F;
  --ink-soft:#4A544D;
  --seal:#A9312A;
  --seal-soft:rgba(169,49,42,.12);
  --bronze:#4C6350;
  --brass:#8C6C28;
  --border:rgba(27,33,31,.16);
  --shadow:rgba(27,33,31,.10);
  --font-display:'Literata','Iowan Old Style','Palatino Linotype',Palatino,'Noto Serif','PT Serif',Georgia,serif;
  --font-body:'Literata','New York','Iowan Old Style',Georgia,'Noto Serif','PT Serif',serif;
  --font-han:'Songti SC','STSong','SimSun','PMingLiU','Noto Serif CJK SC',serif;
  --wrap:1080px;
}
/* tiếng Trung: giữ Literata cho chữ Latinh, chữ Hán rơi về phông Hán tương ứng */
:root[lang="zh-Hant"]{
  --font-display:'Literata','Songti TC','PMingLiU','MingLiU','Noto Serif CJK TC','Songti SC',Georgia,serif;
  --font-body:'Literata','Songti TC','PMingLiU','MingLiU','Noto Serif CJK TC','Songti SC',Georgia,serif;
}
:root[lang="zh-Hans"]{
  --font-display:'Literata','Songti SC','STSong','SimSun','Noto Serif CJK SC',Georgia,serif;
  --font-body:'Literata','Songti SC','STSong','SimSun','Noto Serif CJK SC',Georgia,serif;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --paper:#14181A; --paper-dim:#202623; --panel:#1B211E;
    --ink:#E7E2CF; --ink-soft:#AEB6A7; --seal:#DD5F51; --seal-soft:rgba(221,95,81,.14);
    --bronze:#8FA890; --brass:#C9A15C; --border:rgba(231,226,207,.16); --shadow:rgba(0,0,0,.35);
  }
}
:root[data-theme="dark"]{
  --paper:#14181A; --paper-dim:#202623; --panel:#1B211E;
  --ink:#E7E2CF; --ink-soft:#AEB6A7; --seal:#DD5F51; --seal-soft:rgba(221,95,81,.14);
  --bronze:#8FA890; --brass:#C9A15C; --border:rgba(231,226,207,.16); --shadow:rgba(0,0,0,.35);
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
html,body{margin:0;padding:0}
body{
  background:var(--paper);
  color:var(--ink);
  font-family:var(--font-body);
  font-size:17px;
  line-height:1.72;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
a{color:inherit}
img,svg{max-width:100%}
.wrap{max-width:var(--wrap);margin:0 auto;padding:0 24px}

/* ── giấy dó: vân giấy ─────────────────────────── */
body::before{
  content:"";position:fixed;inset:0;pointer-events:none;z-index:0;opacity:.5;
  background-image:
    radial-gradient(circle at 18% 22%, var(--seal-soft) 0, transparent 42%),
    radial-gradient(circle at 82% 78%, rgba(140,108,40,.10) 0, transparent 45%);
}

/* ── thanh điều hướng ──────────────────────────── */
header.nav{
  position:sticky;top:0;z-index:40;
  backdrop-filter:saturate(1.4) blur(14px);
  -webkit-backdrop-filter:saturate(1.4) blur(14px);
  background:color-mix(in srgb, var(--paper) 82%, transparent);
  border-bottom:1px solid var(--border);
}
.nav-in{display:flex;align-items:center;gap:20px;height:62px}
.brand{display:flex;align-items:center;gap:11px;text-decoration:none;font-family:var(--font-display);letter-spacing:.02em}
.brand img{width:30px;height:30px;display:block}
.brand b{font-weight:600;font-size:17px}
.brand span{font-family:var(--font-han);color:var(--seal);font-size:15px;opacity:.85}
nav.links{margin-left:auto;display:flex;align-items:center;gap:4px}
nav.links a{
  text-decoration:none;color:var(--ink-soft);font-size:15px;
  padding:7px 12px;border-radius:7px;transition:color .2s,background .2s;
}
nav.links a:hover{color:var(--ink);background:var(--seal-soft)}
.theme-btn{
  margin-left:6px;border:1px solid var(--border);background:transparent;color:var(--ink-soft);
  width:34px;height:34px;border-radius:8px;cursor:pointer;font-size:15px;line-height:1;
  font-family:var(--font-han);transition:border-color .2s,color .2s;
}
.theme-btn:hover{border-color:var(--seal);color:var(--seal)}
.theme-btn .ico{
  display:block;margin:auto;width:17px;height:17px;
  fill:none;stroke:currentColor;stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round;
}
.theme-btn .ico-sun{display:none}
.theme-btn.is-dark .ico-sun{display:block}
.theme-btn.is-dark .ico-moon{display:none}
#lang{
  font-family:var(--font-display);font-size:12.5px;font-weight:600;
  letter-spacing:.08em;width:auto;min-width:34px;padding:0 9px;
}
:root[lang^="zh"] #lang{font-family:var(--font-han);font-size:15px;letter-spacing:0;padding:0}
@media(max-width:720px){ nav.links a.opt{display:none} }

/* ── hero ──────────────────────────────────────── */
.hero{position:relative;overflow:hidden;padding:76px 0 64px;isolation:isolate}
#ink-canvas{position:absolute;inset:0;width:100%;height:100%;z-index:-1;pointer-events:none}
.hero-in{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:56px;align-items:center}
@media(max-width:900px){.hero-in{grid-template-columns:1fr;gap:40px}.hero{padding:52px 0 48px}}

.eyebrow{
  display:inline-flex;align-items:center;gap:10px;
  font-size:13px;letter-spacing:.16em;text-transform:uppercase;color:var(--ink-soft);
  border:1px solid var(--border);border-radius:999px;padding:6px 15px;margin-bottom:22px;
}
.eyebrow i{width:6px;height:6px;border-radius:50%;background:var(--seal);font-style:normal;animation:pulse 3.2s ease-in-out infinite}
@keyframes pulse{0%,100%{opacity:.35;transform:scale(.8)}50%{opacity:1;transform:scale(1.25)}}

h1{
  font-family:var(--font-display);font-weight:600;
  font-size:clamp(38px,6vw,60px);line-height:1.12;margin:0 0 8px;letter-spacing:-.01em;
}
.h1-han{
  display:block;font-family:var(--font-han);color:var(--seal);
  font-size:clamp(22px,3.4vw,30px);letter-spacing:.42em;font-weight:400;margin-bottom:14px;opacity:.9;
}
.lede{font-size:clamp(17px,2vw,19.5px);color:var(--ink-soft);max-width:56ch;margin:18px 0 30px}
.lede strong{color:var(--ink);font-weight:600}

.cta{display:flex;flex-wrap:wrap;gap:12px}
.btn{
  display:inline-flex;align-items:center;gap:10px;text-decoration:none;
  padding:12px 22px;border-radius:10px;font-size:16px;font-family:var(--font-display);
  border:1px solid var(--border);transition:transform .18s,box-shadow .22s,background .2s,border-color .2s;
}
.btn .han{font-family:var(--font-han);font-size:17px}
.btn-primary{background:var(--seal);border-color:var(--seal);color:#F6F1E4;box-shadow:0 6px 18px -8px var(--seal)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 12px 26px -10px var(--seal)}
.btn-ghost:hover{transform:translateY(-2px);border-color:var(--seal);color:var(--seal);background:var(--seal-soft)}

/* ── ấn triện xoay ─────────────────────────────── */
.seal-stage{position:relative;display:grid;place-items:center;min-height:320px}
.seal-stage svg.ring{position:absolute;width:100%;max-width:330px;height:auto;overflow:visible}
.ring rect{fill:none;stroke:var(--seal);opacity:.55}
.ring .enso{stroke-width:2.2;stroke-linecap:round;stroke-linejoin:round;stroke-dasharray:1080;stroke-dashoffset:1080;transform:rotate(-1.2deg);transform-origin:center;animation:draw 2.6s cubic-bezier(.5,0,.2,1) .35s forwards}
@keyframes draw{to{stroke-dashoffset:0}}
.ring .halo{stroke-width:1;opacity:.22;stroke-dasharray:3 9;transform-origin:center;animation:spin 64s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}
.ring .glyphs{font-family:var(--font-han);fill:var(--brass);font-size:15px;letter-spacing:.5em;transform-origin:center;animation:spin-r 96s linear infinite;opacity:.75}
@keyframes spin-r{to{transform:rotate(-360deg)}}

.seal-mark{
  position:relative;width:190px;height:190px;display:grid;place-items:center;
  opacity:0;animation:stamp 1s cubic-bezier(.2,1.5,.4,1) 1.5s forwards;
}
@keyframes stamp{
  0%{opacity:0;transform:scale(1.5) rotate(-9deg)}
  55%{opacity:1;transform:scale(.94) rotate(2deg)}
  100%{opacity:1;transform:scale(1) rotate(0)}
}
.seal-mark img{width:100%;height:100%;object-fit:contain;filter:drop-shadow(0 8px 22px var(--shadow));animation:float 7s ease-in-out 2.6s infinite}
@keyframes float{0%,100%{transform:translateY(0)}50%{transform:translateY(-9px)}}
.seal-caption{
  position:absolute;bottom:6px;font-family:var(--font-han);font-size:14px;
  letter-spacing:.5em;color:var(--ink-soft);opacity:0;animation:fade 1.2s ease 2.2s forwards;
}
@keyframes fade{to{opacity:.75}}

/* ── dải chim hạc Đông Sơn ─────────────────────── */
.cloud-band{position:relative;height:76px;overflow:hidden;border-block:1px solid var(--border);background:var(--paper-dim)}
/* Bề ngang cố định 4800px, dịch cố định 600px; max-width:none để thoát
   luật img,svg{max-width:100%} ở trên — nếu bị kẹp, mây sẽ nén lại và hở mép phải. */
.cloud-band svg{position:absolute;top:0;left:0;height:76px;width:4800px;max-width:none;will-change:transform}
.cloud-band svg path{fill:var(--bronze);stroke:none}
.cloud-band .drift{animation:drift linear infinite}
.cloud-band .drift-a{animation-duration:38s;opacity:.55}
.cloud-band .drift-b{animation-duration:62s;opacity:.26}
/* đàn hạc bay từ trái sang phải: dịch từ -600px về 0, đúng một ô lặp nên khít */
@keyframes drift{from{transform:translateX(-600px)}to{transform:translateX(0)}}

/* ── section chung ─────────────────────────────── */
section{position:relative;padding:82px 0;z-index:1}
.sec-head{margin-bottom:44px;max-width:66ch}
.sec-num{
  display:inline-flex;align-items:center;gap:12px;margin-bottom:14px;
  font-family:var(--font-han);color:var(--seal);font-size:15px;letter-spacing:.3em;
}
.sec-num::after{content:"";width:56px;height:1px;background:linear-gradient(90deg,var(--seal),transparent)}
h2{font-family:var(--font-display);font-weight:600;font-size:clamp(27px,4vw,38px);line-height:1.24;margin:0 0 14px;letter-spacing:-.01em}
.sec-head p{color:var(--ink-soft);margin:0;font-size:17.5px}
section p a{color:var(--seal);text-underline-offset:3px}

.reveal{opacity:0;transform:translateY(22px);transition:opacity .8s ease,transform .8s cubic-bezier(.2,.8,.3,1)}
.reveal.in{opacity:1;transform:none}

/* ── thẻ ứng dụng ──────────────────────────────── */
.apps{display:grid;grid-template-columns:1fr 1fr;gap:26px}
@media(max-width:840px){.apps{grid-template-columns:1fr}}
.app{
  position:relative;display:flex;flex-direction:column;text-decoration:none;overflow:hidden;
  background:var(--panel);border:1px solid var(--border);border-radius:16px;padding:34px 32px 30px;
  transition:transform .3s cubic-bezier(.2,.8,.3,1),box-shadow .3s,border-color .3s;
}
.app::after{
  content:"";position:absolute;inset:auto -30% -60% auto;width:280px;height:280px;border-radius:50%;
  background:radial-gradient(circle,var(--seal-soft) 0,transparent 70%);
  opacity:0;transition:opacity .45s;pointer-events:none;
}
.app:hover{transform:translateY(-6px);border-color:color-mix(in srgb,var(--seal) 45%,var(--border));box-shadow:0 22px 44px -26px var(--shadow)}
.app:hover::after{opacity:1}
.app-glyph{
  font-family:var(--font-han);font-size:60px;line-height:1;color:var(--seal);
  margin-bottom:20px;transition:transform .45s cubic-bezier(.2,.8,.3,1);
}
.app:hover .app-glyph{transform:translateY(-3px) rotate(-2deg)}
.app-kicker{font-size:12.5px;letter-spacing:.19em;text-transform:uppercase;color:var(--ink-soft);margin-bottom:9px}
.app h3{font-family:var(--font-display);font-size:24px;font-weight:600;margin:0 0 12px}
.app p{color:var(--ink-soft);margin:0 0 22px;font-size:16.5px;flex:1}
.app-url{
  display:inline-flex;align-items:center;gap:9px;font-family:var(--font-display);
  color:var(--seal);font-size:16px;
}
.app-url .arw{transition:transform .3s}
.app:hover .app-url .arw{transform:translateX(6px)}
.tags{display:flex;flex-wrap:wrap;gap:7px;margin-bottom:20px}
.tag{font-size:12.5px;color:var(--ink-soft);border:1px solid var(--border);border-radius:999px;padding:3px 11px}

/* ── lưới đặc điểm ─────────────────────────────── */
.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--border);border:1px solid var(--border);border-radius:14px;overflow:hidden}
@media(max-width:840px){.grid3{grid-template-columns:1fr}}
.cell{background:var(--paper);padding:30px 26px}
.cell .g{font-family:var(--font-han);font-size:26px;color:var(--brass);display:block;margin-bottom:12px}
.cell h4{font-family:var(--font-display);font-size:18px;font-weight:600;margin:0 0 8px}
.cell p{margin:0;color:var(--ink-soft);font-size:16px}

/* ── câu chuyện / hai cột ──────────────────────── */
.two{display:grid;grid-template-columns:1fr 1fr;gap:52px;align-items:start}
@media(max-width:840px){.two{grid-template-columns:1fr;gap:30px}}
.two p{color:var(--ink-soft);margin:0 0 18px}
.two p:last-child{margin-bottom:0}
.quote{
  border-left:2px solid var(--seal);padding:6px 0 6px 24px;
  font-family:var(--font-display);font-size:20px;line-height:1.6;color:var(--ink);
}
.quote .han{font-family:var(--font-han);color:var(--seal);letter-spacing:.2em;display:block;font-size:16px;margin-top:12px}

/* ── liên hệ ───────────────────────────────────── */
.contact{
  background:var(--panel);border:1px solid var(--border);border-radius:16px;
  padding:44px 40px;display:flex;flex-wrap:wrap;gap:26px;align-items:center;justify-content:space-between;
}
.contact h3{font-family:var(--font-display);font-size:23px;font-weight:600;margin:0 0 8px}
.contact p{margin:0;color:var(--ink-soft);max-width:52ch}

footer{border-top:1px solid var(--border);padding:36px 0 46px;position:relative;z-index:1}
.foot{display:flex;flex-wrap:wrap;gap:16px;align-items:center;justify-content:space-between;color:var(--ink-soft);font-size:15px}
.foot a{color:var(--ink-soft);text-decoration:none;border-bottom:1px solid var(--border)}
.foot a:hover{color:var(--seal);border-color:var(--seal)}
.foot-links{display:flex;flex-wrap:wrap;gap:18px}

@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation:none!important;transition:none!important}
  html{scroll-behavior:auto}
  .reveal{opacity:1;transform:none}
  .ring .enso{stroke-dashoffset:0}
  .seal-mark,.seal-caption{opacity:1}
}