/* ===== T-STEP website — colours taken from the T-STEP logo ===== */
:root{
  --navy:#1d3563; --navy-d:#11203d; --navy-l:#2c4a80;
  --red:#e3392d; --red-d:#c22b21;
  --ink:#1e2430; --muted:#6b7385; --line:#e3e7ee; --bg:#f5f7fb; --white:#fff;
  --radius:14px; --shadow:0 10px 30px rgba(17,32,61,.10);
  --head-h:84px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:'Sarabun','Kanit',system-ui,sans-serif;font-size:17px;line-height:1.7;color:var(--ink);background:#fff}
h1,h2,h3,h4,.btn,.main-nav,.brand-text,.eyebrow,.step-no,.stat strong{font-family:'Kanit',sans-serif}
h1,h2,h3,h4{line-height:1.3;margin:0 0 .5em}
img{max-width:100%;display:block}
a{color:var(--navy);text-decoration:none}
a:hover{color:var(--red)}
.container{width:min(1200px,92%);margin:0 auto}
.narrow{max-width:820px;margin-left:auto;margin-right:auto}
.center{text-align:center}
.muted{color:var(--muted)}
.mt{margin-top:32px}
.lead{font-size:1.12rem;color:#3a4255}

/* ---------- buttons ---------- */
.btn{display:inline-block;padding:12px 28px;border-radius:999px;font-weight:500;font-size:1rem;border:2px solid transparent;cursor:pointer;transition:.25s;text-align:center}
.btn-red{background:var(--red);color:#fff}
.btn-red:hover{background:var(--red-d);color:#fff;transform:translateY(-2px)}
.btn-navy{background:var(--navy);color:#fff}
.btn-navy:hover{background:var(--navy-d);color:#fff}
.btn-ghost{border-color:#fff;color:#fff}
.btn-ghost:hover{background:#fff;color:var(--navy)}
.btn-outline{border-color:var(--navy);color:var(--navy)}
.btn-outline:hover{background:var(--navy);color:#fff}
.btn-block{display:block;width:100%;margin-top:12px}

/* ---------- header ---------- */
.site-header{position:sticky;top:0;z-index:100;background:#fff;box-shadow:0 2px 14px rgba(0,0,0,.06);transition:background .3s,box-shadow .3s}
.site-header.is-transparent{position:fixed;left:0;right:0;background:transparent;box-shadow:none}
.site-header.is-transparent.scrolled{background:#fff;box-shadow:0 2px 14px rgba(0,0,0,.08)}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:var(--head-h);gap:20px}
.brand{display:flex;align-items:center;gap:12px}
.brand img{height:62px;width:auto;background:#fff;border-radius:10px;padding:3px}
.brand-text{display:flex;flex-direction:column;line-height:1.15}
.brand-text strong{font-size:1.15rem;color:var(--navy);letter-spacing:.5px}
.brand-text small{font-size:.8rem;color:var(--muted)}
.is-transparent:not(.scrolled) .brand-text strong,.is-transparent:not(.scrolled) .brand-text small{color:#fff}
.main-nav{display:flex;align-items:center;gap:22px}
.main-nav>ul{display:flex;list-style:none;margin:0;padding:0;gap:6px}
.main-nav li{position:relative}
.main-nav>ul>li>a{display:block;padding:10px 14px;color:var(--ink);font-weight:400;border-radius:8px}
.main-nav>ul>li>a.active,.main-nav>ul>li>a:hover{color:var(--red)}
.is-transparent:not(.scrolled) .main-nav>ul>li>a{color:#fff}
.is-transparent:not(.scrolled) .main-nav>ul>li>a.active,.is-transparent:not(.scrolled) .main-nav>ul>li>a:hover{color:#ffb4ae}
.caret{display:inline-block;width:7px;height:7px;border-right:2px solid currentColor;border-bottom:2px solid currentColor;transform:rotate(45deg) translateY(-3px);margin-left:4px}
.sub-toggle{display:none}
.sub-menu{position:absolute;top:100%;left:0;min-width:240px;background:#fff;list-style:none;margin:0;padding:8px;border-radius:12px;box-shadow:var(--shadow);opacity:0;visibility:hidden;transform:translateY(8px);transition:.2s;border-top:3px solid var(--red)}
.has-sub:hover .sub-menu,.has-sub:focus-within .sub-menu{opacity:1;visibility:visible;transform:none}
.sub-menu a{display:block;padding:10px 14px;border-radius:8px;color:var(--ink)}
.sub-menu a:hover,.sub-menu a.active{background:var(--bg);color:var(--red)}
.nav-cta{padding:9px 20px;font-size:.95rem}
.nav-toggle{display:none;background:none;border:0;width:44px;height:44px;cursor:pointer;padding:10px}
.nav-toggle span{display:block;height:2px;background:var(--navy);margin:6px 0;transition:.3s}
.is-transparent:not(.scrolled) .nav-toggle span{background:#fff}

/* ---------- hero (YouTube background) ---------- */
.hero{position:relative;min-height:100vh;display:flex;align-items:center;overflow:hidden;background:var(--navy-d);color:#fff}
.hero-video{position:absolute;inset:0;pointer-events:none;overflow:hidden;background:center/cover no-repeat}
.hero-video iframe{position:absolute;top:50%;left:50%;width:100vw;height:56.25vw;min-height:100vh;min-width:177.78vh;transform:translate(-50%,-50%) scale(1.15);border:0}
.hero-overlay{position:absolute;inset:0;background:linear-gradient(90deg,rgba(17,32,61,.88) 0%,rgba(17,32,61,.55) 55%,rgba(17,32,61,.25) 100%)}
.hero-content{position:relative;z-index:2;padding:calc(var(--head-h) + 40px) 0 90px}
.hero-small{font-family:'Kanit';letter-spacing:6px;font-size:1.1rem;margin:0;color:#ffb4ae}
.hero-title{font-size:clamp(3rem,9vw,6.5rem);font-weight:700;line-height:1;margin:.1em 0 .15em;letter-spacing:2px}
.hero-title span{display:block;font-size:.38em;font-weight:500;letter-spacing:6px;color:#fff;opacity:.9;margin-top:.3em}
.hero-sub{font-family:'Kanit';font-size:1.4rem;margin:0 0 .4em;border-left:4px solid var(--red);padding-left:14px}
.hero-desc{max-width:620px;font-size:1.08rem;opacity:.92}
.hero-btns{display:flex;flex-wrap:wrap;gap:14px;margin:26px 0 40px}
.hero-stats{display:flex;gap:44px;flex-wrap:wrap}
.stat strong{display:block;font-size:2.4rem;font-weight:600;line-height:1}
.stat span{font-size:.95rem;opacity:.85}
.scroll-down{position:absolute;bottom:26px;left:50%;width:28px;height:46px;border:2px solid #fff;border-radius:16px;transform:translateX(-50%);z-index:2}
.scroll-down::after{content:"";position:absolute;left:50%;top:8px;width:4px;height:8px;background:#fff;border-radius:2px;transform:translateX(-50%);animation:sd 1.6s infinite}
@keyframes sd{0%{opacity:1;top:8px}100%{opacity:0;top:24px}}

/* tag strip */
.tag-strip{background:var(--red);color:#fff}
.tag-strip-inner{display:flex;flex-wrap:wrap;justify-content:center;gap:10px 40px;padding:18px 0;font-family:'Kanit';font-size:1.08rem}
.tag-strip span{position:relative}
.tag-strip span+span::before{content:"";position:absolute;left:-22px;top:50%;width:6px;height:6px;border-radius:50%;background:#fff;opacity:.7}

/* ---------- sections ---------- */
.section{padding:84px 0}
.section-title{font-size:clamp(1.7rem,3.4vw,2.4rem);color:var(--navy);font-weight:600;position:relative;padding-bottom:14px;margin-bottom:18px}
.section-title::after{content:"";position:absolute;bottom:0;left:0;width:60px;height:4px;background:var(--red);border-radius:2px}
.section-title.center::after,.center .section-title::after{left:50%;transform:translateX(-50%)}
.section-title.light{color:#fff}
.section-sub{color:var(--muted);margin:-6px auto 40px}

/* project cards */
.projects-home{background:var(--bg)}
.cat-block{margin:46px 0}
.cat-head{display:flex;justify-content:space-between;align-items:flex-end;margin-bottom:18px;border-bottom:1px solid var(--line);padding-bottom:10px}
.cat-head h3{margin:0;color:var(--navy);font-size:1.45rem}
.cat-head small{font-size:.85rem;color:var(--muted);font-weight:400;margin-left:8px}
.more{color:var(--red);font-family:'Kanit';white-space:nowrap}
.card-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:26px}
.project-card{background:#fff;border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);transition:.3s;display:flex;flex-direction:column;color:var(--ink)}
.project-card:hover{transform:translateY(-6px);box-shadow:0 18px 40px rgba(17,32,61,.18);color:var(--ink)}
.pc-img{position:relative;aspect-ratio:4/3;overflow:hidden}
.pc-img img{width:100%;height:100%;object-fit:cover;transition:transform .6s}
.project-card:hover .pc-img img{transform:scale(1.07)}
.badge{position:absolute;left:12px;top:12px;background:var(--red);color:#fff;font-style:normal;font-size:.8rem;padding:3px 12px;border-radius:999px;font-family:'Kanit'}
.pc-body{padding:16px 20px 20px}
.pc-body h4{margin:0 0 4px;font-size:1.08rem;color:var(--navy)}
.pc-body span{color:var(--muted);font-size:.93rem;display:block}
.product-card .more{display:inline-block;margin-top:10px;font-weight:400}

/* why */
.why-grid{display:grid;grid-template-columns:1fr 1fr;gap:56px;align-items:center}
.why-img img{border-radius:var(--radius);box-shadow:var(--shadow);aspect-ratio:4/3;object-fit:cover;width:100%}
.why-text p{color:#3a4255;margin-bottom:26px}

/* services */
.services{background:linear-gradient(135deg,var(--navy-d),var(--navy))}
.service-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;margin-top:40px}
.service-card{position:relative;border-radius:var(--radius);overflow:hidden;aspect-ratio:4/3;color:#fff}
.service-card img{width:100%;height:100%;object-fit:cover;transition:transform .6s}
.service-card:hover img{transform:scale(1.08)}
.sc-cap{position:absolute;inset:auto 0 0 0;padding:60px 22px 20px;background:linear-gradient(transparent,rgba(10,18,36,.92))}
.sc-cap h3{margin:0;font-size:1.3rem}
.sc-cap p{margin:0;opacity:.85}
.service-card:hover{color:#fff}
.service-card::after{content:"";position:absolute;left:0;bottom:0;height:4px;width:0;background:var(--red);transition:.4s}
.service-card:hover::after{width:100%}

/* steps */
.step-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.step-grid.four{grid-template-columns:repeat(4,1fr)}
.step{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:28px 26px;transition:.3s;position:relative;overflow:hidden}
.step:hover{border-color:var(--red);box-shadow:var(--shadow);transform:translateY(-4px)}
.step-no{display:inline-block;background:var(--navy);color:#fff;font-size:.85rem;padding:3px 14px;border-radius:999px;margin-bottom:12px}
.step h3{font-size:1.15rem;color:var(--navy);margin-bottom:6px}
.step p{margin:0;color:var(--muted);font-size:.97rem}

/* clients */
.clients{background:var(--bg)}
.client-grid{display:grid;grid-template-columns:repeat(6,1fr);gap:18px}
.client{background:#fff;border-radius:12px;height:100px;display:flex;align-items:center;justify-content:center;padding:14px;box-shadow:0 4px 14px rgba(0,0,0,.04);filter:grayscale(1);opacity:.85;transition:.3s}
.client:hover{filter:none;opacity:1}
.client img{max-height:70px;object-fit:contain}
.client span{font-family:'Kanit';color:var(--navy);font-weight:500}

/* cta */
.cta{background:linear-gradient(120deg,var(--navy) 0%,var(--navy-d) 100%);color:#fff}
.cta-grid{display:grid;grid-template-columns:1fr 1fr;gap:56px;align-items:start}
.cta h2{font-size:clamp(2rem,4vw,2.8rem);margin-bottom:6px}
.cta .lead{color:#dfe6f3}
.check-list{list-style:none;padding:0;margin:24px 0}
.check-list li{padding:8px 0 8px 36px;position:relative}
.check-list li::before{content:"✓";position:absolute;left:0;top:7px;width:24px;height:24px;border-radius:50%;background:var(--red);color:#fff;display:flex;align-items:center;justify-content:center;font-size:.8rem}
.cta-form{background:#fff;color:var(--ink);border-radius:var(--radius);padding:32px;box-shadow:0 20px 50px rgba(0,0,0,.25)}
.cta-form h3{color:var(--navy);font-size:1.4rem}
.contact-page .cta-form{box-shadow:var(--shadow);border:1px solid var(--line)}

/* forms */
.contact-form label{display:block;font-size:.93rem;color:#3a4255;margin-bottom:12px}
.contact-form input[type=text],.contact-form input[type=email],.contact-form input[type=tel],.contact-form textarea{width:100%;margin-top:4px;padding:11px 14px;border:1px solid #cfd6e2;border-radius:10px;font:inherit;font-size:1rem;transition:.2s}
.contact-form input:focus,.contact-form textarea:focus{outline:none;border-color:var(--navy);box-shadow:0 0 0 3px rgba(29,53,99,.12)}
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.interest{border:0;padding:0;margin:4px 0 8px;display:grid;grid-template-columns:1fr 1fr;gap:4px 14px}
.interest legend{font-size:.93rem;color:#3a4255;margin-bottom:6px}
.chk{display:flex!important;align-items:center;gap:8px;margin:0!important;cursor:pointer}
.chk input{accent-color:var(--red);width:17px;height:17px}
.hp{position:absolute;left:-9999px;opacity:0;height:0;width:0}
.alert{padding:12px 16px;border-radius:10px;margin-bottom:14px;font-size:.95rem}
.alert-ok{background:#e7f6ec;color:#1d6b38}
.alert-err{background:#fdecea;color:#a3241a}

/* page banner */
.page-banner{position:relative;min-height:340px;display:flex;align-items:flex-end;padding:120px 0 50px;background:var(--navy) center/cover no-repeat;color:#fff}
.page-banner::before{content:"";position:absolute;inset:0;background:linear-gradient(90deg,rgba(17,32,61,.92),rgba(17,32,61,.45))}
.page-banner.small{min-height:240px;background:linear-gradient(120deg,var(--navy),var(--navy-d))}
.page-banner .container{position:relative}
.page-banner h1{font-size:clamp(2rem,5vw,3.2rem);margin:0}
.eyebrow{margin:0;color:#ffb4ae;letter-spacing:3px;text-transform:uppercase;font-size:.95rem}

.filter-tabs{display:flex;flex-wrap:wrap;justify-content:center;gap:10px;margin-bottom:34px}
.filter-tabs a{padding:8px 22px;border-radius:999px;border:1px solid var(--line);color:var(--ink);font-family:'Kanit'}
.filter-tabs a.active,.filter-tabs a:hover{background:var(--navy);border-color:var(--navy);color:#fff}

/* detail */
.detail-grid{display:grid;grid-template-columns:1fr 340px;gap:44px;align-items:start}
.detail-cover{border-radius:var(--radius);width:100%;box-shadow:var(--shadow);cursor:zoom-in}
.detail-desc{margin:26px 0}
.detail-side{position:sticky;top:calc(var(--head-h) + 20px);background:var(--bg);border-radius:var(--radius);padding:26px}
.detail-side h3{color:var(--navy)}
.detail-side dl{margin:0 0 16px}
.detail-side dt{font-size:.85rem;color:var(--muted)}
.detail-side dd{margin:0 0 12px;font-weight:500}
.spec{padding-left:18px;margin:0 0 16px}
.gallery{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}
.gallery img{border-radius:10px;aspect-ratio:4/3;object-fit:cover;cursor:zoom-in;width:100%}
.video-embed{position:relative;aspect-ratio:16/9;border-radius:var(--radius);overflow:hidden;margin:20px 0;box-shadow:var(--shadow)}
.video-embed iframe{position:absolute;inset:0;width:100%;height:100%;border:0}

/* about */
.vm{background:var(--bg)}
.vm-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px}
.vm-card{background:#fff;border-radius:var(--radius);padding:34px;border-top:4px solid var(--red);box-shadow:var(--shadow)}
.vm-card h3{color:var(--navy)}

/* contact page */
.info-cards{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:20px}
.info-card{background:var(--bg);border-radius:12px;padding:18px 20px;border-left:4px solid var(--red)}
.info-card h4{margin:0 0 4px;color:var(--navy)}
.info-card p{margin:0;font-size:.97rem}
.map{margin-top:50px;border-radius:var(--radius);overflow:hidden;aspect-ratio:21/9}
.map iframe{width:100%;height:100%;border:0}

/* footer */
.site-footer{background:var(--navy-d);color:#c5cee0;font-size:.95rem}
.footer-grid{display:grid;grid-template-columns:1.2fr 1.2fr 1fr 1fr;gap:40px;padding:64px 0 40px}
.footer-logo{width:120px;background:#fff;border-radius:12px;padding:6px;margin-bottom:14px}
.site-footer h4{color:#fff;font-size:1.05rem}
.site-footer a{color:#c5cee0}
.site-footer a:hover{color:#fff}
.footer-menu,.footer-contact{list-style:none;padding:0;margin:0}
.footer-menu li,.footer-contact li{padding:3px 0}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding:18px 0;font-size:.85rem;text-align:center}
.float-contact{position:fixed;right:22px;bottom:22px;width:56px;height:56px;border-radius:50%;background:var(--red);color:#fff;display:flex;align-items:center;justify-content:center;font-size:1.5rem;box-shadow:0 8px 24px rgba(227,57,45,.45);z-index:90}
.float-contact:hover{color:#fff;transform:scale(1.07)}

/* lightbox */
.lightbox{position:fixed;inset:0;background:rgba(0,0,0,.88);z-index:200;display:flex;align-items:center;justify-content:center;padding:30px}
.lightbox[hidden]{display:none}
.lightbox img{max-height:90vh;border-radius:8px}
.lb-close{position:absolute;top:16px;right:24px;background:none;border:0;color:#fff;font-size:2.4rem;cursor:pointer}

/* reveal animation */
.reveal{opacity:0;transform:translateY(24px);transition:opacity .7s,transform .7s}
.reveal.in{opacity:1;transform:none}

/* ---------- responsive ---------- */
@media (max-width:1080px){
  .main-nav>ul>li>a{padding:10px 9px}
  .nav-cta{display:none}
  .client-grid{grid-template-columns:repeat(3,1fr)}
  .footer-grid{grid-template-columns:1fr 1fr}
}
@media (max-width:900px){
  :root{--head-h:72px}
  .brand img{height:52px}
  .nav-toggle{display:block}
  .main-nav{position:fixed;top:var(--head-h);left:0;right:0;bottom:0;background:#fff;flex-direction:column;align-items:stretch;padding:20px 6%;transform:translateX(100%);transition:transform .3s;overflow-y:auto}
  .main-nav.open{transform:none}
  .main-nav>ul{flex-direction:column;gap:0}
  .main-nav>ul>li{border-bottom:1px solid var(--line)}
  .main-nav>ul>li>a,.is-transparent:not(.scrolled) .main-nav>ul>li>a{color:var(--ink);padding:14px 4px;font-size:1.1rem}
  .has-sub .caret{display:none}
  .sub-toggle{display:block;position:absolute;right:0;top:6px;width:44px;height:44px;background:none;border:0;cursor:pointer}
  .sub-toggle::after{content:"";position:absolute;left:16px;top:14px;width:9px;height:9px;border-right:2px solid var(--navy);border-bottom:2px solid var(--navy);transform:rotate(45deg);transition:.2s}
  .has-sub.open .sub-toggle::after{transform:rotate(-135deg);top:19px}
  .sub-menu{position:static;opacity:1;visibility:visible;transform:none;box-shadow:none;border:0;display:none;padding:0 0 10px 12px}
  .has-sub.open .sub-menu{display:block}
  .nav-cta{display:block;margin-top:20px}
  .nav-toggle.open span:nth-child(1){transform:translateY(8px) rotate(45deg)}
  .nav-toggle.open span:nth-child(2){opacity:0}
  .nav-toggle.open span:nth-child(3){transform:translateY(-8px) rotate(-45deg)}
  .card-grid,.service-grid{grid-template-columns:1fr 1fr}
  .why-grid,.cta-grid,.detail-grid,.vm-grid{grid-template-columns:1fr}
  .step-grid,.step-grid.four{grid-template-columns:1fr 1fr}
  .detail-side{position:static}
  .section{padding:60px 0}
}
@media (max-width:600px){
  body{font-size:16px}
  .brand-text small{display:none}
  .card-grid,.service-grid,.step-grid,.step-grid.four,.info-cards,.form-row,.interest{grid-template-columns:1fr}
  .client-grid{grid-template-columns:1fr 1fr}
  .hero-stats{gap:26px}
  .stat strong{font-size:1.9rem}
  .footer-grid{grid-template-columns:1fr}
  .gallery{grid-template-columns:1fr 1fr}
  .cta-form{padding:22px}
}