/* =====================================================================
   TEMPLATE · Anthropic-style · design-system (token, swap-safe)
   Clone bản gốc thật anthropic.com · số đo LIVE · font free (Inter+Newsreader)
   ===================================================================== */
:root{
  /* Palette Anthropic (đặt tên): Ivory/Oat/Cloud/Slate + accent Vermilion */
  --bg:#F7EDDF; --ivory:#F7EDDF; --card:#EAD9C5; --dark:#1B130C; --on-dark:#FFF8EE;
  --ink:#1B130C; --ink-muted:#8E8578; --label:#B7AD9E; --border:rgba(27,19,12,.13);
  --accent:#D96457; --accent-contrast:#FFF8EE;
  --font-sans:'Inter',system-ui,sans-serif;
  --font-serif:'Newsreader',Georgia,serif;
  --wrap:1280px; --r:16px; --r-btn:8px;
  --font-mono:ui-monospace,'SFMono-Regular',Menlo,'Roboto Mono',monospace;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--font-sans);
  -webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;line-height:1.5}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
.wrap{width:min(var(--wrap),100% - 40px);margin-inline:auto;padding:0}
.serif{font-family:var(--font-serif)}
.section{padding-block:clamp(56px,7vw,96px)}

/* scroll-reveal (gần đúng anthropic: fade-up khi vào viewport) */
.js .reveal{opacity:0;transform:translateY(18px);transition:opacity .7s cubic-bezier(.2,.6,.2,1),transform .7s cubic-bezier(.2,.6,.2,1)}
.js .reveal.in{opacity:1;transform:none}
@media(prefers-reduced-motion:reduce){.reveal{opacity:1;transform:none;transition:none}}

/* buttons */
.btn{display:inline-flex;align-items:center;gap:8px;font-family:var(--font-sans);font-size:16px;font-weight:400;letter-spacing:-.08px;line-height:1.25;
  padding:8px 16px;border-radius:var(--r-btn);border:1px solid transparent;cursor:pointer;
  transition:transform .18s ease,background .2s,opacity .2s}
.btn .arw{transition:transform .25s}.btn:hover .arw{transform:translateX(4px)}
.btn-dark{background:var(--dark);color:var(--on-dark)}.btn-dark:hover{opacity:.86}
.btn-ghost{background:transparent;border-color:currentColor}.btn-ghost:hover{background:rgba(0,0,0,.05)}
.on-dark .btn-ghost:hover{background:rgba(255,255,255,.08)}

/* header */
.ah-hd{position:sticky;top:0;z-index:50;background:color-mix(in srgb,var(--bg) 86%,transparent);backdrop-filter:blur(10px)}
.ah-hd .wrap{display:flex;align-items:center;justify-content:space-between;height:64px;gap:24px}
.ah-logo{font-size:20px;font-weight:600;letter-spacing:.01em}
.ah-nav{display:flex;gap:26px;font-size:15px}.ah-nav a{opacity:.82}.ah-nav a:hover{opacity:1}
@media(max-width:820px){.ah-nav{display:none}}

/* hero */
.ah-hero{padding-top:clamp(40px,6vw,80px);padding-bottom:80px}
.ah-hero .grid{display:grid;grid-template-columns:minmax(0,760px) minmax(0,1fr);gap:clamp(28px,6vw,90px);align-items:start}
.ah-h1{font-family:var(--font-sans);font-weight:700;font-size:clamp(38px,5.2vw,61px);line-height:1.1;letter-spacing:normal;margin:0}
.ah-h1 u{text-decoration-thickness:2px;text-underline-offset:6px}
.ah-hero .lead{font-family:var(--font-serif);font-size:clamp(19px,1.8vw,24px);line-height:1.4;margin:8px 0 0}
@media(max-width:820px){.ah-hero .grid{grid-template-columns:1fr;gap:20px}}

/* dark statement */
.ah-dark{background:var(--bg);color:var(--on-dark);text-align:center;padding:0 clamp(14px,2vw,32px) 0}
.hq-stage{--mx:0;--my:0;--stage-w:84vw;--stage-radius:22px;
  position:relative;overflow:hidden;min-height:clamp(610px,74vw,760px);width:var(--stage-w);
  max-width:calc(100vw - clamp(28px,4vw,64px));margin:0 auto;background:var(--dark);
  border-radius:var(--stage-radius);display:grid;place-items:center;isolation:isolate;
  transition:width 1s cubic-bezier(.2,.7,.2,1),border-radius 1s ease}
.hq-stage.hq-in{--stage-w:calc(100vw - clamp(28px,4vw,64px));--stage-radius:8px}
.hq-stage:before{content:"";position:absolute;inset:0;z-index:1;pointer-events:none;
  background:radial-gradient(circle at 50% 53%,rgba(20,20,19,0) 0 31%,rgba(20,20,19,.44) 55%,rgba(20,20,19,.86) 100%)}
.hq-copy{position:relative;z-index:4;max-width:min(760px,74vw);padding:40px 20px;
  transform:translate(calc(var(--mx)*-5px),calc(var(--my)*-5px));transition:transform .4s cubic-bezier(.2,.6,.2,1)}
.ah-dark h2{font-family:var(--font-serif);font-weight:400;font-size:clamp(46px,5.25vw,88px);line-height:1.03;margin:0}
.ah-dark p{font-size:clamp(17px,1.38vw,23px);line-height:1.36;color:rgba(250,249,245,.82);max-width:52ch;margin:28px auto 32px}
.btn-light{background:var(--on-dark);color:var(--dark);border-color:rgba(250,249,245,.18)}
.btn-light:hover{background:#e8e4d8}
.hq-lines{position:absolute;inset:0;z-index:2;width:100%;height:100%;display:block;
  transform:translate(calc(var(--mx)*8px),calc(var(--my)*8px));transition:transform .4s cubic-bezier(.2,.6,.2,1)}
.hq-line{stroke:var(--on-dark);stroke-width:1.15;stroke-linecap:round;opacity:0}
.hq-label{position:absolute;z-index:3;font-family:var(--font-serif);font-size:clamp(22px,1.9vw,32px);
  line-height:1.08;text-align:center;max-width:220px;color:rgba(250,249,245,.66);opacity:0;
  text-shadow:0 1px 22px rgba(20,20,19,.92),0 0 10px rgba(20,20,19,.7);
  transform:translate(-50%,-50%) translateY(20px);
  transition:opacity .8s ease,transform 1s cubic-bezier(.2,.7,.2,1)}
.hq-in .hq-label{opacity:1;transform:translate(-50%,-50%) translateY(0)}
.q-work{left:14%;top:40%;transition-delay:.5s}.q-govern{left:66%;top:13%;transition-delay:.62s}
.q-use{left:83%;top:33%;transition-delay:.72s}.q-society{left:17%;top:85%;transition-delay:.82s}
.q-economy{left:84%;top:85%;transition-delay:.92s}
.hq-tile{position:absolute;z-index:3;width:48px;aspect-ratio:1;margin:0;opacity:0;
  transform:translate(-50%,-50%) translateY(30px) scale(.5);
  transition:opacity .7s ease,transform .9s cubic-bezier(.2,.7,.2,1)}
.hq-in .hq-tile{opacity:1;transform:translate(-50%,-50%) translateY(0) scale(1)}
.hq-tile.wide{width:58px;aspect-ratio:1.35}.hq-tile.tall{width:42px;aspect-ratio:.82}
.hq-tile span{position:relative;display:block;width:100%;height:100%;overflow:hidden;border-radius:2px;
  background:var(--tile-bg,linear-gradient(135deg,#c6c4ba,#786d5a));box-shadow:0 0 0 1px rgba(250,249,245,.08)}
.hq-tile span:before,.hq-tile span:after{content:"";position:absolute;inset:0;mix-blend-mode:multiply}
.hq-tile span:before{background:var(--tile-mark,repeating-linear-gradient(90deg,transparent 0 8px,rgba(20,20,19,.28) 8px 10px));opacity:.5}
.hq-tile span:after{background:radial-gradient(circle at var(--spot-x,64%) var(--spot-y,34%),rgba(250,249,245,.42),transparent 34%);
  opacity:.55;mix-blend-mode:screen}
.hq-tile span{animation:hq-float 8.5s ease-in-out infinite;animation-delay:var(--float-delay,0s)}
.t1{left:15%;top:22%;transition-delay:.1s;--float-delay:-1s;--tile-bg:linear-gradient(90deg,#86a5bd 0 28%,#d7cfc0 28% 58%,#455048 58%);--tile-mark:linear-gradient(0deg,rgba(250,249,245,.4) 0 18%,transparent 18% 52%,rgba(20,20,19,.25) 52% 70%,transparent 70%)}
.t2{left:10%;top:38%;transition-delay:.16s;--float-delay:-2s;--tile-bg:linear-gradient(135deg,#6dbd65 0 52%,#f2eee2 52%);--tile-mark:radial-gradient(circle at 72% 42%,transparent 0 18%,#141413 19% 22%,transparent 23%)}
.t3{left:20%;top:40%;transition-delay:.22s;--float-delay:-3.5s;--tile-bg:radial-gradient(circle at 20% 62%,#f06f3d,transparent 35%),radial-gradient(circle at 80% 40%,#d94fab,transparent 34%),linear-gradient(135deg,#e5b53a,#73a5bb);--tile-mark:linear-gradient(120deg,transparent 0 62%,rgba(20,20,19,.36) 63%)}
.t4{left:13%;top:51%;transition-delay:.28s;--float-delay:-.4s;--tile-bg:linear-gradient(145deg,#f1e3bf 0 58%,#b8754b 58%);--tile-mark:repeating-linear-gradient(25deg,transparent 0 9px,rgba(20,20,19,.16) 9px 11px)}
.t5{left:18%;top:58%;transition-delay:.34s;--float-delay:-4s;--tile-bg:linear-gradient(90deg,#6e9bc7 0 42%,#d8ddd1 42%);--tile-mark:radial-gradient(circle at 62% 38%,rgba(20,20,19,.5) 0 18%,transparent 19%)}
.t6{left:21%;top:72%;transition-delay:.4s;--float-delay:-2.6s;--tile-bg:linear-gradient(155deg,#78b5a5 0 56%,#161616 56%);--tile-mark:repeating-linear-gradient(65deg,transparent 0 8px,rgba(250,249,245,.18) 8px 9px)}
.t7{left:14%;top:84%;transition-delay:.46s;--float-delay:-1.7s;--tile-bg:linear-gradient(100deg,#b8b08e 0 42%,#541c25 42% 78%,#cf7b69 78%);--tile-mark:repeating-linear-gradient(110deg,transparent 0 7px,rgba(250,249,245,.2) 7px 8px)}
.t8{left:32%;top:87%;transition-delay:.52s;--float-delay:-3.1s;--tile-bg:linear-gradient(135deg,#35566f 0 48%,#72a7c7 48%);--tile-mark:linear-gradient(45deg,transparent 0 48%,rgba(20,20,19,.42) 49% 52%,transparent 53%)}
.t9{left:49%;top:89%;transition-delay:.58s;--float-delay:-.8s;--tile-bg:linear-gradient(90deg,#acd1dc 0 36%,#1c2f64 36% 62%,#d83832 62%);--tile-mark:radial-gradient(circle at 42% 45%,transparent 0 11%,rgba(20,20,19,.45) 12% 15%,transparent 16%)}
.t10{left:55%;top:89%;transition-delay:.64s;--float-delay:-2.1s;--tile-bg:linear-gradient(135deg,#f3f0e8,#d4d0c0);--tile-mark:radial-gradient(circle at 50% 52%,transparent 0 23%,#141413 24% 26%,transparent 27%)}
.t11{left:74%;top:93%;transition-delay:.7s;--float-delay:-3.7s;--tile-bg:linear-gradient(135deg,#465b42,#a7b591);--tile-mark:repeating-linear-gradient(-25deg,transparent 0 6px,rgba(20,20,19,.22) 6px 8px)}
.t12{left:79%;top:41%;transition-delay:.28s;--float-delay:-1.4s;--tile-bg:linear-gradient(90deg,#e68661 0 32%,#d9c5bd 32% 78%,#171717 78%);--tile-mark:repeating-linear-gradient(100deg,transparent 0 9px,rgba(20,20,19,.55) 9px 11px)}
.t13{left:88%;top:40%;transition-delay:.34s;--float-delay:-2.9s;--tile-bg:linear-gradient(105deg,#dedde8 0 54%,#4c4b4d 54%);--tile-mark:repeating-linear-gradient(75deg,transparent 0 4px,rgba(20,20,19,.28) 4px 5px)}
.t14{left:92%;top:4%;transition-delay:.16s;--float-delay:-3.4s;--tile-bg:linear-gradient(135deg,#d2d6ca,#4f5850);--tile-mark:repeating-linear-gradient(75deg,transparent 0 5px,rgba(250,249,245,.28) 5px 6px)}
.t15{left:84%;top:4%;transition-delay:.22s;--float-delay:-.9s;--tile-bg:linear-gradient(135deg,#281a1d,#6b2022);--tile-mark:repeating-linear-gradient(35deg,transparent 0 9px,rgba(250,249,245,.2) 9px 10px)}
.t16{left:66%;top:4%;transition-delay:.28s;--float-delay:-2.3s;--tile-bg:linear-gradient(90deg,#773146 0 50%,#2d151b 50%);--tile-mark:radial-gradient(circle at 30% 45%,rgba(250,249,245,.2),transparent 38%)}
.t17{left:59%;top:20%;transition-delay:.34s;--float-delay:-1.8s;--tile-bg:linear-gradient(90deg,#bfdbdc 0 47%,#4a86bc 47%);--tile-mark:radial-gradient(circle at 18% 28%,#b5d76b 0 9%,transparent 10%),radial-gradient(circle at 34% 55%,#99a942 0 9%,transparent 10%)}
.t18{left:73%;top:21%;transition-delay:.4s;--float-delay:-3.9s;--tile-bg:linear-gradient(135deg,#8ca474 0 54%,#203826 54%);--tile-mark:repeating-linear-gradient(30deg,transparent 0 7px,rgba(250,249,245,.16) 7px 9px)}
@keyframes hq-float{0%,100%{transform:translate3d(0,0,0) rotate(0deg)}50%{transform:translate3d(0,-6px,0) rotate(.5deg)}}
@media(prefers-reduced-motion:reduce){
  .hq-stage,.hq-copy,.hq-lines,.hq-tile,.hq-label{transition:none!important}
  .hq-copy,.hq-lines{transform:none!important}
  .hq-tile,.hq-label{opacity:1!important;transform:translate(-50%,-50%)!important}
  .hq-tile span{animation:none!important}
  .hq-line{opacity:.18!important}
}
@media(max-width:900px){
  .hq-stage{min-height:640px}.hq-copy{max-width:86vw}
  .ah-dark h2{font-size:clamp(40px,9vw,68px)}
  .ah-dark p{font-size:17px}
  .q-use,.q-economy,.t7,.t8,.t9,.t10,.t11,.t14,.t15{display:none}
  .q-work{left:18%;top:31%}.q-govern{left:74%;top:18%}.q-society{left:52%;top:88%}
  .t1{left:14%;top:17%}.t2{left:11%;top:42%}.t3{left:23%;top:39%}.t4{left:16%;top:54%}
  .t5{left:26%;top:65%}.t6{left:69%;top:79%}.t12{left:82%;top:36%}.t13{left:91%;top:49%}
  .t16{left:60%;top:8%}.t17{left:78%;top:8%}.t18{left:70%;top:27%}
}
@media(max-width:560px){
  .ah-dark{padding-inline:10px}.hq-stage{max-width:calc(100vw - 20px);min-height:590px}
  .hq-stage:before{background:radial-gradient(circle at 50% 52%,rgba(20,20,19,.08) 0 38%,rgba(20,20,19,.76) 74%)}
  .hq-lines{opacity:.72}.hq-label{font-size:22px}
  .q-work{left:25%;top:20%}.q-govern{left:72%;top:23%}.q-society{left:50%;top:83%}
  .hq-tile{width:40px}.hq-tile.wide{width:48px}.hq-tile.tall{width:36px}
  .t2,.t5,.t12,.t13{display:none}
}
/* HQ layout v2 (desktop >=901): sắp xếp có hệ thống - tiles gom vào 4 dải rìa,
   nhãn ở vành quanh center, chừa sạch vùng chữ giữa; ẩn 2 tile gây rối. */
@media(min-width:901px){
  .t3,.t7{display:none}
  /* dải trái */
  .t1{left:10%;top:12%}.t2{left:18%;top:21%}.t4{left:9%;top:62%}.t5{left:17%;top:73%}.t6{left:8%;top:83%}
  /* dải phải */
  .t14{left:90%;top:11%}.t16{left:83%;top:21%}.t11{left:91%;top:61%}.t13{left:85%;top:73%}.t18{left:92%;top:83%}
  /* dải trên (phía trên copy) */
  .t17{left:41%;top:10%}.t12{left:47%;top:9%}.t15{left:74%;top:7%}
  /* dải dưới (phía dưới copy) */
  .t8{left:42%;top:90%}.t9{left:50%;top:93%}.t10{left:58%;top:90%}
  /* nhãn: vành quanh center, thoáng, không đè tile/center */
  .q-work{left:11%;top:42%}.q-use{left:89%;top:42%}
  .q-govern{left:60%;top:11%}
  .q-society{left:22%;top:88%}.q-economy{left:80%;top:88%}
}

/* releases (section nền ivory · card nền sáng hơn, radius 16, pad 32) */
.ah-rel{background:var(--ivory);padding:80px 0 0}
/* NOTE type: px gốc anthropic = eyebrow/title 24, desc 18 (đo LIVE). Ở đây phóng lên
   (26 / 20) CHỦ ĐÍCH để bù font free (Inter/Newsreader) nhìn mảnh hơn Anthropic Sans/Serif,
   cho khớp cảm giác mẫu. Không phải sai số đo. */
.ah-eyebrow{font-size:26px;font-weight:600;line-height:1.3;letter-spacing:normal;margin:0 0 28px}
.ah-rel-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:32px}
/* min-height: card gốc cao 467; ở đây 503 để bù font đã phóng, cho khoảng trống dưới
   mô tả (Model details -> vạch DATE) ~118px giống mẫu. meta+nút dính đáy nhờ margin-top:auto. */
.ah-card{background:var(--card);border-radius:var(--r);padding:32px;min-height:503px;
  display:flex;flex-direction:column;gap:0;transition:transform .25s ease,box-shadow .25s ease}
.ah-card:hover{transform:translateY(-3px);box-shadow:0 14px 34px rgba(20,20,19,.07)}
.ah-card h3{font-size:26px;font-weight:600;letter-spacing:normal;line-height:1.3;margin:0}
.ah-card .desc{font-family:var(--font-serif);font-size:20px;line-height:1.4;margin:8px 0 0}
.ah-card .mdl{font-size:16px;font-weight:400;letter-spacing:-.08px;margin:18px 0 0;display:inline-flex;gap:6px;align-items:center}
.ah-card .mdl .arw{transition:transform .25s}.ah-card .mdl:hover .arw{transform:translateX(4px)}
.ah-card .meta{display:flex;justify-content:space-between;gap:12px;padding:12px 0;border-top:1px solid var(--border);font-family:var(--font-sans);font-size:16px;line-height:1.4;color:var(--ink)}
.ah-card .meta:first-of-type{margin-top:auto}
.ah-card .meta .k{font-family:var(--font-mono);text-transform:uppercase;letter-spacing:normal;color:var(--ink)}
.ah-card .btn{margin-top:20px;align-self:flex-start}
@media(max-width:900px){.ah-rel-grid{grid-template-columns:1fr}}

/* topics / link list */
.ah-topics{padding:80px 0 0}
.ah-topics .grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.5fr);gap:clamp(28px,6vw,90px);align-items:start}
.ah-topics .big{font-size:clamp(22px,2.3vw,26px);font-weight:600;line-height:1.24;letter-spacing:-.01em;margin:0;max-width:15ch}
.ah-row{display:flex;justify-content:space-between;align-items:center;gap:16px;padding:22px 0;border-top:1px solid var(--border)}
.ah-row:last-child{border-bottom:1px solid var(--border)}
.ah-row h3{font-size:16px;font-weight:600;margin:0}
.ah-row .cat{font-size:14px;color:var(--label);white-space:nowrap}
.ah-row .arw{margin-left:auto;opacity:0;transform:translateX(-6px);transition:all .25s}
.ah-row:hover .arw{opacity:.5;transform:none}
@media(max-width:640px){.ah-topics .grid{grid-template-columns:1fr;gap:20px}.ah-row .cat{display:none}}
/* footer */
.ah-foot{background:var(--dark);color:var(--on-dark);padding:80px 0 40px}
.ah-foot .cols{display:grid;grid-template-columns:auto repeat(4,1fr);gap:32px}
.ah-foot .flogo{font-size:22px;font-weight:600}
.ah-foot h4{font-size:12px;font-weight:500;letter-spacing:.06em;text-transform:uppercase;color:rgba(250,249,245,.55);margin:0 0 12px}
.ah-foot a{display:block;font-size:14px;color:rgba(250,249,245,.82);padding:4px 0}.ah-foot a:hover{color:var(--on-dark)}
.ah-foot .bar{display:flex;justify-content:space-between;gap:16px;margin-top:48px;padding-top:20px;border-top:1px solid rgba(250,249,245,.14);font-size:13px;color:rgba(250,249,245,.6);flex-wrap:wrap}
@media(max-width:820px){.ah-foot .cols{grid-template-columns:1fr 1fr}}