/* ===== GRC2026 — Design system ===== */
:root{
  --navy-900:#040917;
  --navy-800:#071130;
  --navy-700:#0b1c45;
  --navy-600:#12295e;
  --line:rgba(120,170,255,.18);
  --blue:#22a7f0;
  --blue-bright:#4fc3ff;
  --blue-deep:#0b64d0;
  --gold:#f5c343;
  --gold-deep:#c9962a;
  --ink:#e9f2ff;
  --ink-dim:#a9bede;
  --ink-mute:#7d93b5;
  --white:#fff;
  --radius:18px;
  --radius-sm:12px;
  --wrap:1180px;
  --shadow:0 18px 48px rgba(0,0,0,.45);
  --font:"IBM Plex Sans Thai",-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
  --font-display:"Chakra Petch","IBM Plex Sans Thai",sans-serif;
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:88px}
body{
  margin:0;font-family:var(--font);font-size:17px;line-height:1.75;color:var(--ink);
  background:var(--navy-900);
  background-image:
    radial-gradient(1100px 620px at 12% -8%,rgba(34,167,240,.20),transparent 60%),
    radial-gradient(900px 560px at 92% 4%,rgba(245,195,67,.10),transparent 62%),
    radial-gradient(900px 700px at 50% 110%,rgba(11,100,208,.18),transparent 65%);
  background-attachment:fixed;
  overflow-x:hidden;
}
img{max-width:100%;height:auto;display:block}
a{color:var(--blue-bright);text-decoration:none}
a:hover{text-decoration:underline}
/* ภาษาไทยไม่มีเว้นวรรคระหว่างคำ ต้องบังคับให้ตัดบรรทัดได้ ไม่งั้นข้อความจะดันจนล้นจอ */
h1,h2,h3,h4,p,li,td,th,dd,dt,figcaption,label,summary,address{overflow-wrap:anywhere;word-break:normal}
h1,h2,h3,h4{font-family:var(--font-display);line-height:1.28;margin:0 0 .5em;letter-spacing:.2px}
h1{font-size:clamp(1.9rem,4.6vw,3.1rem)}
h2{font-size:clamp(1.45rem,3vw,2.15rem)}
h3{font-size:clamp(1.12rem,2vw,1.4rem)}
p{margin:0 0 1em}
ul,ol{margin:0 0 1em;padding-left:1.35em}
li{margin-bottom:.4em}
hr{border:0;border-top:1px solid var(--line);margin:2.5rem 0}
:focus-visible{outline:3px solid var(--gold);outline-offset:3px;border-radius:6px}
.wrap{width:min(var(--wrap),calc(100% - 40px));margin-inline:auto}
.muted{color:var(--ink-dim)}
.tiny{font-size:.86rem;color:var(--ink-mute)}
.center{text-align:center}

.skip{position:absolute;left:-9999px;top:0;background:var(--gold);color:#111;padding:12px 20px;z-index:200;border-radius:0 0 10px 0}
.skip:focus{left:0}

/* ===== Header ===== */
.site-header{
  position:sticky;top:0;z-index:100;
  background:rgba(4,9,23,.72);backdrop-filter:blur(14px);
  border-bottom:1px solid var(--line);
}
.header-inner{display:flex;align-items:center;gap:16px;min-height:70px}
.brand{display:flex;align-items:center;gap:11px;color:var(--white);text-decoration:none;flex-shrink:0}
.brand img{border-radius:9px;background:#fff;padding:3px;width:44px;height:44px;object-fit:contain}
.brand-text{display:flex;flex-direction:column;line-height:1.15}
.brand-text b{font-family:var(--font-display);font-size:1.28rem;letter-spacing:1px}
.brand-text small{font-size:.63rem;color:var(--ink-mute);letter-spacing:1.3px;text-transform:uppercase}
.nav{margin-left:auto;display:flex;align-items:center;gap:18px}
.nav ul{display:flex;gap:5px;list-style:none;margin:0;padding:0}
.nav a{color:var(--ink-dim);font-size:.93rem;padding:9px 11px;border-radius:9px;white-space:nowrap;text-decoration:none;font-weight:500}
.nav a:hover{color:var(--white);background:rgba(255,255,255,.07)}
.nav a[aria-current=page]{color:var(--gold)}
.burger{display:none;margin-left:auto;background:none;border:1px solid var(--line);border-radius:10px;width:44px;height:44px;cursor:pointer;padding:0;align-items:center;justify-content:center;flex-direction:column;gap:5px}
.burger span{display:block;width:20px;height:2px;background:var(--ink);transition:.25s}
.burger[aria-expanded=true] span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.burger[aria-expanded=true] span:nth-child(2){opacity:0}
.burger[aria-expanded=true] span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

/* ===== Buttons ===== */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:9px;
  padding:13px 26px;border-radius:999px;font-weight:600;font-size:1rem;
  text-decoration:none;border:1px solid transparent;cursor:pointer;
  transition:transform .18s ease,box-shadow .18s ease,background .18s ease;
  font-family:var(--font);
}
.btn:hover{text-decoration:none;transform:translateY(-2px)}
.btn-gold{background:linear-gradient(135deg,var(--gold),var(--gold-deep));color:#221803;box-shadow:0 10px 26px rgba(245,195,67,.3)}
.btn-gold:hover{box-shadow:0 14px 34px rgba(245,195,67,.42)}
.btn-blue{background:linear-gradient(135deg,var(--blue),var(--blue-deep));color:#fff;box-shadow:0 10px 26px rgba(34,167,240,.32)}
.btn-ghost{border-color:var(--line);color:var(--ink);background:rgba(255,255,255,.04)}
.btn-ghost:hover{background:rgba(255,255,255,.1)}
.btn-sm{padding:9px 18px;font-size:.9rem}
.btn-block{width:100%}

/* ===== Hero slider ===== */
.hero{
  position:relative;overflow:hidden;padding:58px 0 66px;border-bottom:1px solid var(--line);
  background:
    radial-gradient(920px 520px at 8% -10%,rgba(34,167,240,.26),transparent 62%),
    radial-gradient(760px 460px at 96% 108%,rgba(245,195,67,.13),transparent 64%),
    linear-gradient(158deg,#07132e 0%,#040917 72%);
}
.hero-inner{display:grid;grid-template-columns:minmax(0,1.04fr) minmax(0,.96fr);gap:50px;align-items:center}
.hero-copy{min-width:0}
.hero-media{display:grid;grid-template-columns:minmax(0,1fr);place-items:center;min-width:0}
.slide-tag{display:inline-block;background:rgba(245,195,67,.14);border:1px solid rgba(245,195,67,.4);color:var(--gold);padding:7px 16px;border-radius:16px;font-size:.83rem;font-weight:600;margin-bottom:20px;letter-spacing:.4px;max-width:100%}
.slide-texts{display:grid;grid-template-columns:minmax(0,1fr)}
.slide-text,.slide-fig{grid-area:1/1;opacity:0;transition:opacity .7s ease;pointer-events:none}
.slide-text.is-active,.slide-fig.is-active{opacity:1;pointer-events:auto}
.slide-text h1,.slide-text .slide-title{font-size:clamp(1.8rem,3.5vw,2.85rem);margin-bottom:.45em;max-width:17ch}
.slide-text p{font-size:clamp(1rem,1.4vw,1.12rem);color:var(--ink-dim);max-width:52ch;margin-bottom:1.6em}
.slide-actions{display:flex;gap:14px;flex-wrap:wrap}
.slide-fig{display:grid;place-items:center}
.slide-fig img{
  max-height:clamp(340px,58vh,560px);width:auto;max-width:100%;object-fit:contain;
  border-radius:16px;border:1px solid var(--line);box-shadow:var(--shadow);background:#050d22;
}
.hero-dots{display:flex;gap:10px;margin-top:30px}
.hero-dots button{width:11px;height:11px;border-radius:50%;border:1px solid rgba(255,255,255,.55);background:transparent;cursor:pointer;padding:0;transition:.2s}
.hero-dots button[aria-selected=true]{background:var(--gold);border-color:var(--gold);width:30px;border-radius:999px}

/* ===== Countdown ===== */
.countdown{display:flex;gap:12px;flex-wrap:wrap;margin:28px 0 0}
.cd-box{background:rgba(255,255,255,.06);border:1px solid var(--line);border-radius:14px;padding:12px 18px;text-align:center;min-width:84px;backdrop-filter:blur(8px)}
.cd-box b{display:block;font-family:var(--font-display);font-size:1.85rem;line-height:1;color:var(--gold)}
.cd-box span{font-size:.76rem;color:var(--ink-mute)}

/* ===== Sections ===== */
.section{padding:76px 0}
.section-tight{padding:52px 0}
.section-alt{background:rgba(7,17,48,.55);border-block:1px solid var(--line)}
.sec-head{max-width:720px;margin-bottom:44px}
.sec-head.center{margin-inline:auto;text-align:center}
.eyebrow{display:block;color:var(--blue-bright);font-weight:600;font-size:.86rem;letter-spacing:2.2px;text-transform:uppercase;margin-bottom:10px}
.lead{font-size:1.1rem;color:var(--ink-dim)}

/* ===== Cards ===== */
.grid{display:grid;gap:22px}
.grid>*{min-width:0}
.grid-2{grid-template-columns:repeat(auto-fit,minmax(min(320px,100%),1fr))}
.grid-3{grid-template-columns:repeat(auto-fill,minmax(min(300px,100%),1fr))}
.grid-4{grid-template-columns:repeat(auto-fill,minmax(min(230px,100%),1fr))}
.card{
  background:linear-gradient(160deg,rgba(18,41,94,.62),rgba(7,17,48,.72));
  border:1px solid var(--line);border-radius:var(--radius);padding:26px;
  transition:transform .22s ease,border-color .22s ease,box-shadow .22s ease;
  position:relative;overflow:hidden;display:flex;flex-direction:column;
}
a.card{color:inherit;text-decoration:none}
.card:hover{transform:translateY(-4px);border-color:rgba(79,195,255,.5);box-shadow:0 18px 44px rgba(0,0,0,.4)}
.card-icon{font-size:2.1rem;line-height:1;margin-bottom:14px}
.card h3{margin-bottom:.35em}
.card .en{color:var(--ink-mute);font-size:.84rem;letter-spacing:.6px;margin:-.3em 0 .7em;display:block;font-family:var(--font-display)}
.card p{color:var(--ink-dim);font-size:.96rem;flex:1}
.card-more{color:var(--gold);font-weight:600;font-size:.92rem;margin-top:12px}

.pill{display:inline-block;background:rgba(34,167,240,.14);border:1px solid rgba(34,167,240,.36);color:var(--blue-bright);padding:3px 11px;border-radius:999px;font-size:.78rem;font-weight:600;margin:0 6px 6px 0}
.pill-gold{background:rgba(245,195,67,.13);border-color:rgba(245,195,67,.4);color:var(--gold)}
.pill-teacher{background:rgba(160,120,255,.14);border-color:rgba(160,120,255,.4);color:#c4a9ff}

/* ===== Stats ===== */
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(150px,100%),1fr));gap:18px}
.stats>*{min-width:0}
.stat{text-align:center;padding:26px 14px;background:rgba(255,255,255,.045);border:1px solid var(--line);border-radius:var(--radius)}
.stat b{display:block;font-family:var(--font-display);font-size:clamp(1.9rem,4vw,2.7rem);color:var(--gold);line-height:1.1}
.stat span{color:var(--ink-dim);font-size:.92rem}

/* ===== Competition list ===== */
.filters{display:flex;gap:9px;flex-wrap:wrap;margin-bottom:30px}
.filters button{
  background:rgba(255,255,255,.05);border:1px solid var(--line);color:var(--ink-dim);
  padding:9px 18px;border-radius:999px;cursor:pointer;font-size:.92rem;font-family:var(--font);transition:.2s;font-weight:500;
}
.filters button:hover{color:var(--white);border-color:rgba(79,195,255,.5)}
.filters button[aria-pressed=true]{background:linear-gradient(135deg,var(--blue),var(--blue-deep));color:#fff;border-color:transparent}
.comp-card{display:flex;flex-direction:column}
.comp-no{position:absolute;top:14px;right:18px;font-family:var(--font-display);font-size:2.6rem;color:rgba(255,255,255,.06);line-height:1}
.comp-card h3{padding-right:44px}

/* ===== Table ===== */
.table-scroll{overflow-x:auto;border:1px solid var(--line);border-radius:var(--radius);background:rgba(7,17,48,.5)}
table{border-collapse:collapse;width:100%;min-width:560px;font-size:.95rem}
caption{text-align:left;padding:16px 18px;font-family:var(--font-display);font-size:1.15rem;color:var(--gold);border-bottom:1px solid var(--line)}
th,td{padding:12px 16px;text-align:left;border-bottom:1px solid rgba(120,170,255,.1);vertical-align:top}
th{background:rgba(34,167,240,.1);font-weight:600;color:var(--white);white-space:nowrap}
tbody tr:hover{background:rgba(255,255,255,.03)}
tbody tr:last-child td{border-bottom:0}

/* ===== Prose ===== */
.prose{max-width:74ch}
.prose h2{margin-top:2em;color:var(--gold)}
.prose h2:first-child{margin-top:0}
.prose h3{margin-top:1.6em}
.prose li{color:var(--ink-dim)}
.prose strong{color:var(--white)}

/* ===== FAQ ===== */
.faq-item{border:1px solid var(--line);border-radius:var(--radius-sm);margin-bottom:12px;background:rgba(7,17,48,.5);overflow:hidden}
.faq-item summary{padding:18px 22px;cursor:pointer;font-weight:600;list-style:none;display:flex;justify-content:space-between;gap:16px;align-items:flex-start}
.faq-item summary::-webkit-details-marker{display:none}
.faq-item summary::after{content:"+";font-size:1.5rem;color:var(--gold);line-height:1;flex-shrink:0;transition:.2s}
.faq-item[open] summary::after{transform:rotate(45deg)}
.faq-item .faq-a{padding:0 22px 20px;color:var(--ink-dim)}

/* ===== Gallery ===== */
.gallery-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(min(240px,100%),1fr));gap:14px}
.gallery-grid a{display:block;border-radius:var(--radius-sm);overflow:hidden;border:1px solid var(--line);background:#050d22;aspect-ratio:4/3;transition:.22s}
.gallery-grid a:hover{transform:translateY(-3px);border-color:rgba(79,195,255,.55)}
.gallery-grid img{width:100%;height:100%;object-fit:cover}
.video-embed{position:relative;padding-top:56.25%;border-radius:var(--radius);overflow:hidden;border:1px solid var(--line);background:#000}
.video-embed iframe{position:absolute;inset:0;width:100%;height:100%;border:0}

/* Lightbox */
.lb{position:fixed;inset:0;background:rgba(2,5,14,.95);z-index:300;display:none;align-items:center;justify-content:center;padding:24px}
.lb[open],.lb.is-open{display:flex}
.lb img{max-width:min(92vw,900px);max-height:82vh;object-fit:contain;border-radius:10px;image-rendering:auto}
.lb-close,.lb-prev,.lb-next{position:absolute;background:rgba(255,255,255,.1);border:1px solid var(--line);color:#fff;width:48px;height:48px;border-radius:50%;font-size:1.4rem;cursor:pointer;display:grid;place-items:center}
.lb-close{top:20px;right:20px}
.lb-prev{left:20px;top:50%;transform:translateY(-50%)}
.lb-next{right:20px;top:50%;transform:translateY(-50%)}
.lb-cap{position:absolute;bottom:20px;left:0;right:0;text-align:center;color:var(--ink-dim);font-size:.9rem;padding:0 20px}

/* ===== Forms ===== */
.form{display:grid;gap:16px;max-width:640px}
.field{display:grid;gap:7px}
.field label{font-weight:600;font-size:.94rem}
.field .req{color:var(--gold)}
input,select,textarea{
  font-family:var(--font);font-size:1rem;padding:13px 15px;border-radius:11px;
  border:1px solid var(--line);background:rgba(4,9,23,.65);color:var(--ink);width:100%;
}
input:focus,select,textarea:focus{border-color:var(--blue)}
select{cursor:pointer}
select option{background:var(--navy-800);color:var(--ink)}
textarea{min-height:130px;resize:vertical}
.hp{position:absolute!important;left:-9999px!important;width:1px;height:1px;overflow:hidden}
.form-note{font-size:.86rem;color:var(--ink-mute)}
.alert{padding:15px 18px;border-radius:12px;margin-bottom:20px;border:1px solid}
.alert-ok{background:rgba(46,204,113,.12);border-color:rgba(46,204,113,.42);color:#8ff0b8}
.alert-err{background:rgba(231,76,60,.12);border-color:rgba(231,76,60,.42);color:#ffb3aa}

/* ===== Promo bar ===== */
.promo{display:flex;gap:16px;align-items:center;flex-wrap:wrap;background:linear-gradient(120deg,rgba(245,195,67,.14),rgba(34,167,240,.1));border:1px solid rgba(245,195,67,.35);border-radius:var(--radius);padding:20px 26px;margin-bottom:16px}
.promo b{color:var(--gold);display:block;font-family:var(--font-display);font-size:1.1rem}
.promo p{margin:.25em 0 0;color:var(--ink-dim);font-size:.95rem;flex:1;min-width:240px}

/* ===== Split media ===== */
.split{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(320px,100%),1fr));gap:40px;align-items:center}
.split>*{min-width:0}
.split img{border-radius:var(--radius);border:1px solid var(--line)}

/* ===== Breadcrumb ===== */
.crumbs{padding:20px 0 0;font-size:.88rem;color:var(--ink-mute)}
.crumbs ol{list-style:none;display:flex;flex-wrap:wrap;gap:8px;padding:0;margin:0}
.crumbs li+li::before{content:"›";margin-right:8px;color:var(--ink-mute)}
.crumbs a{color:var(--ink-dim)}

/* ===== Page head ===== */
.page-head{padding:44px 0 8px}
.page-head p.lead{max-width:70ch}

/* ===== Downloads ===== */
.dl-list{display:grid;gap:12px}
.dl{display:flex;align-items:center;gap:16px;padding:16px 20px;border:1px solid var(--line);border-radius:var(--radius-sm);background:rgba(7,17,48,.5);transition:.2s;color:inherit;text-decoration:none}
.dl:hover{border-color:rgba(79,195,255,.5);transform:translateX(3px);text-decoration:none}
.dl-ico{font-size:1.5rem;flex-shrink:0}
.dl b{display:block;font-weight:600}
.dl span{font-size:.85rem;color:var(--ink-mute)}

/* ===== Footer ===== */
.site-footer{border-top:1px solid var(--line);background:rgba(2,6,18,.72);margin-top:60px;padding:56px 0 0}
.footer-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(230px,100%),1fr));gap:36px;padding-bottom:38px}
.footer-grid>*{min-width:0}
.footer-logo{border-radius:10px;background:#fff;padding:4px;margin-bottom:14px}
.footer-name{font-family:var(--font-display);font-size:1.05rem;color:var(--white);margin-bottom:.5em}
.foot-h{font-size:1rem;color:var(--gold);font-family:var(--font-display);margin-bottom:.9em}
.foot-links{list-style:none;padding:0;margin:0}
.foot-links li{margin-bottom:.5em}
.foot-links a{color:var(--ink-dim);font-size:.94rem}
.site-footer address{font-style:normal;font-size:.94rem;line-height:1.85}
.qr{border-radius:10px;background:#fff;padding:6px;margin-top:14px}
.partners-title{margin:20px 0 8px;font-size:.85rem;color:var(--ink-mute)}
.partner-logos{display:flex;gap:10px;flex-wrap:wrap}
.partner-logos img{border-radius:8px;background:#fff;padding:3px;width:52px;height:52px;object-fit:contain}
.copyright{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;padding:20px 0;border-top:1px solid var(--line);font-size:.86rem;color:var(--ink-mute)}
.copyright p{margin:0}
.copyright a{color:var(--ink-mute)}

/* ===== Sticky CTA (mobile) ===== */
.sticky-cta{
  display:none;position:fixed;left:16px;right:16px;bottom:16px;z-index:90;
  background:linear-gradient(135deg,var(--gold),var(--gold-deep));color:#221803;
  text-align:center;padding:15px;border-radius:999px;font-weight:700;
  box-shadow:0 12px 30px rgba(0,0,0,.5);text-decoration:none;
}

/* ===== Responsive ===== */
@media (max-width:1040px){
  .nav ul{gap:0}
  .nav a{padding:8px 8px;font-size:.88rem}
}
@media (max-width:900px){
  body{font-size:16px}
  .burger{display:flex}
  .nav{
    position:fixed;inset:70px 0 auto;background:rgba(4,9,23,.98);backdrop-filter:blur(18px);
    flex-direction:column;align-items:stretch;gap:0;padding:16px 20px 28px;
    border-bottom:1px solid var(--line);display:none;max-height:calc(100vh - 70px);overflow-y:auto;
  }
  .nav.is-open{display:flex}
  .nav ul{flex-direction:column;gap:2px}
  .nav a{padding:14px 12px;font-size:1rem;display:block;border-radius:10px}
  .nav-cta{margin-top:14px;justify-content:center;display:inline-flex}
  .hero{padding:40px 0 48px}
  .hero-inner{grid-template-columns:minmax(0,1fr);gap:34px}
  .slide-fig img{max-height:400px}
  .hero-dots{justify-content:center}
  .section{padding:56px 0}
  .sticky-cta{display:block}
  body{padding-bottom:76px}
  .copyright{justify-content:center;text-align:center}
}
@media (max-width:520px){
  .wrap{width:calc(100% - 32px)}
  .card{padding:20px}
  .countdown{gap:8px}
  .cd-box{min-width:70px;padding:10px 12px}
  .cd-box b{font-size:1.5rem}
  .gallery-grid{grid-template-columns:repeat(auto-fill,minmax(min(150px,100%),1fr));gap:10px}
}

@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important;scroll-behavior:auto!important}
  .slide{transition:none}
}

@media print{
  .site-header,.site-footer,.sticky-cta,.hero-dots,.filters{display:none}
  body{background:#fff;color:#000}
}

/* ===== เกียรติบัตร ===== */
.cert-card .cert-thumb{display:block;border-radius:var(--radius-sm);overflow:hidden;border:1px solid var(--line);background:#fff;margin-bottom:18px}
.cert-card .cert-thumb:hover{border-color:rgba(79,195,255,.6)}
.cert-card .cert-thumb img{width:100%;height:auto;display:block;transition:transform .3s ease}
.cert-card .cert-thumb:hover img{transform:scale(1.02)}
.cert-card h3{margin-bottom:.2em}
.btn[disabled]{opacity:.55;cursor:not-allowed}
.btn[disabled]:hover{transform:none}