/* aist.org.vn — giao diện phỏng theo aisvntogether.com: navy #173B6C, xanh #2764A5, cam #E08D2D, nền tối #1D1E20, Open Sans */
:root{
  --navy:#173B6C; --navy-2:#0E3A6D; --blue:#2764A5; --orange:#E08D2D; --orange-2:#D35400;
  --dark:#1D1E20; --ink:#1D1E20; --ink-2:#4A5563; --mute:#6F7A86;
  --paper:#FFFFFF; --soft:#F5FAFF; --line:#E1E7EF; --line-2:#C9D3E0;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--paper);color:var(--ink);font-family:"Open Sans",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;font-size:17px;line-height:1.65;-webkit-font-smoothing:antialiased}
@media(max-width:600px){body{font-size:16px}}
img{max-width:100%;height:auto}
a{color:var(--blue)}
h1,h2,h3,h4{line-height:1.25;margin:0 0 .5em;text-wrap:balance;font-weight:700}
h1{font-size:clamp(1.85rem,3.8vw,2.6rem);letter-spacing:-.02em}
h2{font-size:clamp(1.4rem,2.4vw,1.9rem);color:var(--navy);letter-spacing:-.01em}
h3{font-size:1.15rem;color:var(--navy)}
h4{font-size:1rem}
p{margin:0 0 1em}
ul{margin:0 0 1em;padding-left:1.3em}
li{margin:.25em 0}
.wrap{max-width:1140px;margin:0 auto;padding:0 20px}
.small{font-size:.85rem;color:var(--mute)}
.center{text-align:center}

/* ===== notice bar ===== */
.notice{background:var(--dark);color:#fff;font-size:.84rem;text-align:center;padding:7px 0}
.notice .wrap{display:flex;flex-wrap:wrap;justify-content:center;gap:2px 14px}
.notice a{color:#FFD27A;text-decoration:none;font-weight:600;white-space:nowrap}
.notice a:hover{text-decoration:underline}
.notice .n-short{display:none}
@media(max-width:640px){.notice{font-size:.8rem}.notice .n-long{display:none}.notice .n-short{display:inline}}

/* ===== header ===== */
.site-header{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:50;box-shadow:0 1px 0 rgba(23,59,108,.03)}
.site-header .wrap{display:flex;align-items:center;gap:8px;min-height:72px}
.brand{flex:none;margin-right:22px}
.brand img{display:block;height:56px;width:auto;border-radius:0}
.nav{display:flex;align-items:center;justify-content:space-between;gap:0 2px;flex:1;min-width:0;max-width:760px}
.nav a{color:var(--ink);text-decoration:none;font-size:.9rem;font-weight:600;padding:8px 9px;border-radius:6px;white-space:nowrap}
.nav a:hover{background:var(--soft);color:var(--navy)}
.nav a.cur{color:var(--navy);box-shadow:inset 0 -3px 0 var(--orange)}
.nav .nl-l{display:none}
.nav-right{display:flex;align-items:center;gap:8px;flex:none;margin-left:auto;padding-left:12px}
.nav-cta{background:var(--navy);color:#fff;text-decoration:none;font-size:.9rem;font-weight:600;padding:9px 16px;border-radius:8px;white-space:nowrap}
.nav-cta:hover,.nav-cta.cur{background:var(--blue)}
.lang{border:1px solid var(--line-2);color:var(--ink);text-decoration:none;padding:7px 10px;border-radius:6px;font-size:.8rem;font-weight:600;letter-spacing:.06em}
.lang:hover{background:var(--soft)}
.nav-toggle{display:none;background:none;border:0;padding:8px;cursor:pointer;margin-right:-8px}
.nav-toggle span{display:block;width:24px;height:2px;background:var(--navy);margin:5px 0;transition:transform .2s,opacity .2s}
body.nav-open .nav-toggle span:nth-child(1){transform:translateY(7px) rotate(45deg)}
body.nav-open .nav-toggle span:nth-child(2){opacity:0}
body.nav-open .nav-toggle span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
@media(max-width:1180px){.nav a{font-size:.86rem;padding:8px 7px}.nav-cta{padding:9px 13px;font-size:.86rem}}
@media(max-width:1060px){
  .site-header .wrap{min-height:64px}
  .brand img{height:48px}
  .nav-toggle{display:block}
  .nav{display:none;position:absolute;left:0;right:0;top:100%;background:#fff;border-bottom:1px solid var(--line);flex-direction:column;align-items:stretch;padding:6px 20px 14px;box-shadow:0 12px 24px rgba(23,59,108,.08);max-height:calc(100vh - 64px);overflow:auto}
  .nav a{padding:12px 6px;border-bottom:1px solid var(--line);border-radius:0;font-size:.95rem}
  .nav a.cur{box-shadow:inset 3px 0 0 var(--orange);padding-left:12px}
  .nav .nl-s{display:none}.nav .nl-l{display:inline}
  body.nav-open .nav{display:flex}
}
@media(max-width:600px){
  .nav-cta{padding:8px 11px;font-size:.8rem}
  .lang{padding:6px 8px;font-size:.74rem}
  .nav-right{gap:6px}
}
@media(max-width:400px){.brand img{height:44px}.nav-cta{padding:8px 9px;font-size:.76rem}}

/* ===== buttons ===== */
.btn{display:inline-block;font-weight:600;text-decoration:none;padding:12px 22px;border-radius:8px;font-size:.98rem;border:0;cursor:pointer;font-family:inherit;transition:filter .15s}
.btn:hover{filter:brightness(1.08)}
.btn-orange{background:var(--orange);color:#0D141A}
.btn-blue{background:var(--blue);color:#fff}
.btn-navy{background:var(--navy);color:#fff}
.btn-white{background:#fff;color:var(--navy)}
.btn-outline{background:transparent;color:var(--navy);border:2px solid var(--navy)}
.btn-sm{padding:8px 14px;font-size:.88rem}
.btns{display:flex;gap:12px;flex-wrap:wrap;margin-top:22px}

/* ===== hero ===== */
.hero{padding:64px 0 60px;background:var(--dark);color:#fff;background-size:cover;background-position:center}
.hero .eyebrow{font-size:.8rem;letter-spacing:.14em;text-transform:uppercase;color:#FFD27A;font-weight:700;margin-bottom:12px}
.hero h1{color:#fff;max-width:26ch}
.hero .lead{font-size:1.1rem;max-width:60ch;color:#DCE3EC}
.hero .lead p{margin:0 0 .5em}
.hero-navy{background:var(--navy)}
.hero-soft{background:var(--soft);color:var(--ink)}
.hero-soft h1{color:var(--navy)}.hero-soft .lead{color:var(--ink-2)}.hero-soft .eyebrow{color:var(--orange-2)}

/* ===== sections ===== */
section{padding:52px 0}
section.soft{background:var(--soft)}
section.tight{padding:32px 0}
.split-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:44px;align-items:center}
.split-grid.img-left .split-img{order:-1}
.split-img img{border-radius:14px;box-shadow:0 10px 30px rgba(23,59,108,.12);width:100%;object-fit:cover}
@media(max-width:820px){.split-grid{grid-template-columns:1fr;gap:24px}.split-grid.img-left .split-img{order:0}}
.split-text ul li{margin:.35em 0}
.cta-band{background:var(--navy);color:#fff;text-align:center;padding:64px 0}
.cta-band h2{color:#fff;font-size:clamp(1.4rem,2.8vw,2rem)}
.cta-band p{max-width:70ch;margin:0 auto 1em;color:#DCE3EC;font-size:1.05rem}
.cta-band .btn{margin-top:14px}

.cards3{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
@media(max-width:820px){.cards3{grid-template-columns:1fr}}
.card{background:#fff;border:1px solid var(--line);border-radius:14px;padding:26px 24px;box-shadow:0 6px 20px rgba(23,59,108,.06)}
.card .num{display:inline-block;background:var(--orange);color:#0D141A;font-weight:800;font-size:.78rem;letter-spacing:.1em;padding:4px 10px;border-radius:99px;margin-bottom:12px}
.card h3{margin-bottom:.4em}
.card p:last-child{margin-bottom:0}
.principle{border-top:4px solid var(--orange)}

.two-col{display:grid;grid-template-columns:1fr 1fr;gap:36px;align-items:start}
@media(max-width:820px){.two-col{grid-template-columns:1fr}}
.gallery3{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-top:22px}
.gallery3 img{width:100%;height:210px;object-fit:cover;border-radius:12px}
@media(max-width:700px){.gallery3{grid-template-columns:1fr 1fr}.gallery3 img{height:150px}}
@media(max-width:420px){.gallery3{grid-template-columns:1fr}}
.video{position:relative;padding-top:56.25%;border-radius:14px;overflow:hidden;background:#000;box-shadow:0 10px 30px rgba(23,59,108,.15)}
.video iframe{position:absolute;inset:0;width:100%;height:100%;border:0}
.quote{font-size:1.15rem;font-weight:600;color:var(--navy);border-left:4px solid var(--orange);padding:6px 18px;margin:18px 0}
.checklist{list-style:none;padding:0}
.checklist li{padding-left:1.8em;position:relative}
.checklist li::before{content:"✔";position:absolute;left:0;color:var(--blue);font-weight:700}
.crosslist{list-style:none;padding:0}
.crosslist li{padding-left:1.8em;position:relative}
.crosslist li::before{content:"✖";position:absolute;left:0;color:var(--orange-2);font-weight:700}
.docbox{background:var(--soft);border:1px solid var(--line);border-radius:12px;padding:18px 22px;display:flex;flex-wrap:wrap;align-items:center;gap:10px 18px;margin:18px 0}
.docbox b{color:var(--navy)}
.section-head{text-align:center;max-width:70ch;margin:0 auto 34px}
.section-head p{color:var(--ink-2)}

/* ===== steps ===== */
.steps{counter-reset:step;display:grid;gap:18px}
.step{display:grid;grid-template-columns:56px 1fr;gap:16px;align-items:start}
.step .n{width:56px;height:56px;border-radius:50%;background:var(--navy);color:#fff;display:grid;place-items:center;font-weight:800;font-size:1.1rem}
.step h3{margin:.3em 0 .2em}

/* ===== news ===== */
.news-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:26px}
@media(max-width:820px){.news-grid{grid-template-columns:1fr}}
.news-card{background:#fff;border:1px solid var(--line);border-radius:14px;overflow:hidden;display:flex;flex-direction:column;box-shadow:0 6px 20px rgba(23,59,108,.05)}
.news-card .card-img img{width:100%;height:240px;object-fit:cover;display:block}
.news-card .card-body{padding:20px 22px 22px}
.news-card h3{font-size:1.15rem;margin:.4em 0 .5em}
.news-card h3 a{color:var(--navy);text-decoration:none}
.news-card h3 a:hover{text-decoration:underline}
.news-card p{color:var(--ink-2);font-size:.95rem}
.tag{display:inline-block;font-size:.7rem;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--orange-2);background:#FFF1DF;padding:3px 9px;border-radius:99px}
.meta{font-size:.82rem;color:var(--mute)}
.pager{display:flex;gap:8px;justify-content:center;margin-top:34px}
.pager a,.pager span{min-width:40px;text-align:center;padding:8px 12px;border:1px solid var(--line-2);border-radius:8px;text-decoration:none;color:var(--navy);font-weight:600}
.pager span.cur{background:var(--navy);color:#fff;border-color:var(--navy)}

/* article */
.article{max-width:820px;margin:0 auto}
.article-head{padding:44px 0 20px}
.article-head h1{color:var(--navy)}
.article-head .lead{font-size:1.1rem;color:var(--ink-2);border-left:4px solid var(--orange);padding-left:16px;margin:18px 0}
.article-body{padding-bottom:40px}
.article-body h2{font-size:1.4rem;margin-top:1.6em}
.article-body h3{font-size:1.15rem;margin-top:1.3em}
.article-body img{display:block;margin:22px auto;border-radius:12px;max-height:640px;object-fit:contain}
.article-body .video{margin:22px 0}
.article-body a{word-break:break-word}
.article-cover img{width:100%;max-height:480px;object-fit:cover;border-radius:14px}
.related{border-top:1px solid var(--line);padding-top:30px}

/* ===== faq ===== */
.faq details{border:1px solid var(--line);border-radius:10px;background:#fff;margin-bottom:10px;padding:0 18px}
.faq summary{cursor:pointer;font-weight:700;color:var(--navy);padding:14px 0;list-style:none;display:flex;justify-content:space-between;gap:12px}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";color:var(--orange);font-size:1.3rem;flex:none}
.faq details[open] summary::after{content:"–"}
.faq details p,.faq details ul{color:var(--ink-2)}
.faq .body{padding:0 0 14px}
.banner{background:var(--navy);color:#fff;text-align:center;padding:22px;border-radius:12px;font-weight:700;font-size:1.1rem;margin-bottom:26px}

/* ===== docs ===== */
.doclist{display:grid;gap:14px}
.doc{display:flex;flex-wrap:wrap;align-items:center;gap:10px 18px;background:#fff;border:1px solid var(--line);border-radius:12px;padding:18px 22px}
.doc .ic{font-size:1.5rem}
.doc .t{flex:1;min-width:220px}
.doc .t b{color:var(--navy);display:block}
.doc .t small{color:var(--mute)}
.doc .btn{padding:8px 14px;font-size:.86rem}

/* ===== win-win ===== */
.winners{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:16px}
.winner{background:#fff;border:1px solid var(--line);border-left:5px solid var(--blue);border-radius:10px;padding:16px 18px}
.winner b{display:block;color:var(--navy);margin-bottom:6px}
.winner p{margin:0;font-size:.95rem;color:var(--ink-2)}

/* ===== sponsors ===== */
.person{display:grid;grid-template-columns:200px 1fr;gap:26px;align-items:center;background:#fff;border:1px solid var(--line);border-radius:16px;padding:24px;max-width:760px;margin:0 auto 34px}
.person img{width:200px;height:200px;object-fit:cover;border-radius:12px}
.person .role{color:var(--orange-2);font-weight:700;font-size:.85rem;letter-spacing:.06em;text-transform:uppercase}
.person .tags{display:flex;flex-wrap:wrap;gap:6px;margin:10px 0}
.person .tags span{background:var(--soft);border:1px solid var(--line);border-radius:99px;padding:3px 10px;font-size:.82rem}
@media(max-width:600px){.person{grid-template-columns:1fr;text-align:center}.person img{margin:0 auto}.person .tags{justify-content:center}}
.logos{display:flex;flex-wrap:wrap;gap:24px;justify-content:center;margin:20px 0 36px}
.logos img{height:90px;width:auto;object-fit:contain}

/* ===== contact ===== */
.form{display:grid;gap:14px}
.form label{font-weight:600;font-size:.95rem}
.form input,.form textarea{width:100%;font:inherit;padding:11px 13px;border:1px solid var(--line-2);border-radius:8px;margin-top:5px}
.form input:focus,.form textarea:focus{outline:2px solid var(--blue);outline-offset:1px;border-color:var(--blue)}
.form .req{color:var(--orange-2)}
.msg{padding:12px 16px;border-radius:8px;margin:12px 0}
.msg.ok{background:#E6F4EA;color:#1E5E3A}.msg.err{background:#FDECEA;color:#9A2E22}

/* ===== footer ===== */
.site-footer{background:var(--navy);color:#D5DEEA;padding:56px 0 0;margin-top:20px;font-size:.95rem}
.site-footer a{color:#fff;text-decoration:none}
.site-footer a:hover{text-decoration:underline}
.site-footer h4{color:#fff;font-size:.82rem;letter-spacing:.12em;text-transform:uppercase;margin:0 0 16px;padding-bottom:10px;border-bottom:2px solid var(--orange);display:inline-block}
.footer-grid{display:grid;grid-template-columns:1.25fr 1fr 1.25fr auto;gap:40px;align-items:start}
.f-brand img{width:150px;height:auto;border-radius:0;background:transparent;display:block;margin-top:-6px}
.f-tag{font-weight:600;color:#fff;margin:18px 0 0;max-width:30ch;line-height:1.5}
.f-links{list-style:none;padding:0;margin:0}
.f-links li{margin:0 0 9px;line-height:1.45;display:flex;gap:10px}
.f-k{flex:none;width:68px;color:#9FB0C6;font-size:.82rem;text-transform:uppercase;letter-spacing:.05em;padding-top:2px}
.f-btn{margin:18px 0 0}
.site-footer .btn-sm{background:var(--orange);color:#0D141A;text-decoration:none}
.site-footer .btn-sm:hover{text-decoration:none}
.f-zalo{text-align:center}
.f-zalo img{width:140px;height:140px;border-radius:12px;background:#fff;padding:6px;display:block;margin:0 auto}
.f-zalo .small{color:#B8C6D8;font-size:.82rem;margin:12px 0 0;line-height:1.5}
.f-note{margin-top:44px;padding-top:24px;border-top:1px solid rgba(255,255,255,.15);font-size:.86rem;color:#B8C6D8;line-height:1.6;text-align:center}
.f-note p{margin:0 auto .5em;max-width:84ch}
.f-bottom{margin-top:28px;background:var(--navy-2);padding:14px 0;text-align:center;font-size:.8rem;color:#B8C6D8;letter-spacing:.02em}
@media(max-width:960px){
  .footer-grid{grid-template-columns:1fr 1.2fr auto;gap:34px 28px}
  .f-brand{grid-column:1/-1;display:flex;align-items:center;gap:22px}
  .f-brand img{width:120px;margin:0}
  .f-tag{margin:0}
}
@media(max-width:700px){
  .footer-grid{grid-template-columns:1fr 1fr}
  .f-zalo{grid-column:1/-1;padding-top:6px}
}
@media(max-width:560px){
  .site-footer{padding-top:40px}
  .footer-grid{grid-template-columns:1fr;gap:30px}
  .f-brand{flex-direction:column;text-align:center;gap:14px}
  .f-tag{max-width:none}
  .f-zalo{text-align:center}
  .f-zalo img{margin:0 auto}
  .f-note{margin-top:34px}
}

/* ===== tracker page host ===== */
.page-tracker main{background:#F4F7F6}
.tracker-intro{background:var(--navy);color:#fff;padding:28px 0}
.tracker-intro h1{color:#fff;font-size:1.5rem;margin:0}
.tracker-intro p{margin:6px 0 0;color:#DCE3EC}
img.img-broken{background:#EAF1F8;min-height:40px;object-fit:cover}
/* Nói rõ để tránh hiểu nhầm (trang chủ) */
.myth-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}
.myth-card{background:#fff;border:1px solid #DCE6F2;border-radius:14px;padding:20px 22px}
.myth-card .say{font-style:italic;color:#4B5B6B;border-left:3px solid #E08D2D;padding-left:12px;margin-bottom:10px;font-weight:600}
.myth-card p{margin:0;font-size:.97rem;line-height:1.55}
.myth-card p b{color:#173B6C}
@media (max-width:760px){.myth-grid{grid-template-columns:1fr}}
.archive-note{background:#FFF7E8;border:1px solid #F3D9A6;border-left:4px solid #E08D2D;border-radius:10px;padding:12px 16px;margin:0 0 22px;font-size:.92rem;color:#5B4A2A}