:root{
  --ink:#2E2E36; /* Bastille */
  --gray:#5A5A5A;
  --gray-soft:#6E6E6E;
  --muted:#8A8A8A;
  --faint:#B4B4B4;
  --paper:#FFFFFF;
  --paper-dim:#FAFAFA;
  --line:#EDEDED;
  --line-strong:#E4E4E4;

  --corporate:#2288CA;
  --corporate-deep:#1B6FA0; /* AA-safe on white text */
  --culf:#671DDB;
  --culf-tint:#F1EBFC;
  --artkey:#FE2C54;
  --artkey-tint:#FDEBEF;
  --class:#B98900;
  --class-tint:#FBF2DC;

  --sans:'Pretendard', -apple-system, BlinkMacSystemFont, sans-serif;
}
*{margin:0;padding:0;box-sizing:border-box;}
html{scroll-behavior:smooth;}
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto;}
  *{animation-duration:.001ms !important; transition-duration:.001ms !important;}
}
body{
  background:var(--paper);
  color:var(--ink);
  font-family:var(--sans);
  line-height:1.6;
  font-size:16px;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
  word-break:keep-all;
  overflow-wrap:break-word;
}
a{color:inherit; text-decoration:none;}
img{max-width:100%; display:block;}
::selection{background:var(--ink); color:var(--paper);}
a:focus-visible, button:focus-visible{outline:2px solid var(--corporate); outline-offset:3px;}

.wrap{max-width:1200px; margin:0 auto; padding:0 48px;}
@media (max-width:640px){ .wrap{padding:0 22px;} }

.reveal{opacity:0; transform:translateY(24px); transition:opacity .7s cubic-bezier(.2,.7,.2,1), transform .7s cubic-bezier(.2,.7,.2,1);}
.reveal.in{opacity:1; transform:translateY(0);}

.label{font-size:12px; font-weight:700; letter-spacing:.2em; text-transform:uppercase;}
.eyebrow{display:flex; align-items:baseline; gap:12px; margin-bottom:22px;}

/* ---------- header ---------- */
header{
  position:sticky; top:0; z-index:80;
  background:rgba(255,255,255,.9);
  backdrop-filter:blur(10px);
  -webkit-backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line);
}
.nav-inner{
  max-width:1200px; margin:0 auto; padding:20px 48px;
  display:flex; align-items:center; justify-content:space-between;
}
@media (max-width:640px){ .nav-inner{padding:18px 22px;} }
.logo{display:flex; align-items:center; gap:10px; font-weight:800; font-size:14.5px; letter-spacing:.1em; font-family:var(--sans);}
.nav-links{display:flex; gap:30px; font-size:13.5px; font-weight:600; color:var(--gray);}
.nav-links a{transition:color .2s;}
.nav-links a:hover{color:var(--corporate);}
@media (max-width:680px){ .nav-links{display:none;} }

section{padding:96px 0;}
@media (max-width:680px){ section{padding:64px 0;} }

.btn{
  font-weight:700; font-size:13.5px;
  padding:15px 28px;
  display:inline-flex; align-items:center; gap:8px;
  transition:transform .18s ease, background .18s ease, color .18s ease;
  cursor:pointer;
  border:none;
  font-family:var(--sans);
}
.btn-pill{border-radius:999px;}

.link-arrow{
  display:inline-flex; align-items:center; gap:6px;
  font-weight:700; font-size:14px; font-family:var(--sans);
}
.link-arrow .arrow{display:inline-block; transition:transform .18s ease;}
.link-arrow:hover .arrow{transform:translate(3px,-3px);}

/* ---------- hero (home, dark) ---------- */
.hero{
  position:relative; overflow:hidden;
  background:var(--ink); color:#fff;
  padding-top:104px; padding-bottom:96px;
}
@media (max-width:680px){ .hero{padding-top:64px; padding-bottom:64px;} }
.hero::before{
  content:"";
  position:absolute; inset:0;
  background-image:url('hero-bg.jpg');
  background-size:cover;
  background-position:center 38%;
  filter:grayscale(1) contrast(1.08);
}
.hero::after{
  content:"";
  position:absolute; inset:0;
  background:rgba(46,46,54,.7);
}
.hero .wrap{position:relative; z-index:1;}
.hero .kicker{color:var(--corporate); margin-bottom:30px;}
.hero h1{
  font-family:var(--sans);
  font-weight:800;
  font-size:clamp(40px, 5.8vw, 72px);
  line-height:1.16;
  letter-spacing:-0.02em;
  word-spacing:.18em;
  max-width:920px;
  margin-bottom:36px;
}
.hero-bottom{display:flex; flex-direction:column; align-items:flex-start; gap:28px;}
.hero .lede{font-size:16px; line-height:1.8; color:#C7C6CE;}
.btn-hero{background:var(--corporate-deep); color:#fff;}
.btn-hero:hover{background:var(--corporate);}

/* ---------- page header (about) ---------- */
.page-header{padding-top:72px; padding-bottom:56px;}
@media (max-width:680px){ .page-header{padding-top:52px; padding-bottom:40px;} }
.page-header .label{color:var(--corporate); margin-bottom:24px;}
.page-header h1{
  font-weight:800;
  font-size:clamp(30px, 4vw, 48px);
  line-height:1.2;
  letter-spacing:-0.02em;
  word-spacing:.2em;
}

/* ---------- service sections ---------- */
.service-culf{}
.service-artkey{background:var(--paper-dim);}
.service h2{
  font-weight:800;
  line-height:1.28;
  letter-spacing:-0.02em;
  word-spacing:.26em;
  margin-bottom:8px;
}

/* CULF row: text | image */
.culf-inner{display:grid; grid-template-columns:1.05fr .95fr; gap:56px; align-items:start;}
@media (max-width:860px){ .culf-inner{grid-template-columns:1fr;} }
.culf-inner h2{font-size:clamp(28px,3.6vw,44px); margin-bottom:0;}
.culf-inner .desc{font-family:var(--sans); font-size:15.5px; line-height:1.8; color:var(--gray); max-width:430px; margin:24px 0 32px;}
.media-frame{
  width:100%; overflow:hidden; border-radius:12px;
  box-shadow:0 12px 32px rgba(26,26,34,.10);
}
.media-frame img{width:100%; height:100%; object-fit:cover;}
.frame-culf{aspect-ratio:3/2;}
.frame-artkey, .frame-class{aspect-ratio:2/3;}
@media (max-width:640px){
  .media-frame{
    border-radius:0; box-shadow:none;
    width:100vw; max-width:100vw;
    margin-left:calc(50% - 50vw);
  }
}

/* ARTKEY intro */
.artkey-intro h2{font-size:clamp(26px,3.2vw,40px); margin-bottom:8px;}
.artkey-intro .desc{font-family:var(--sans); font-size:15.5px; line-height:1.8; color:var(--gray); margin:16px 0 56px;}

/* ARTKEY service cards: image | text | image | text, four across */
.artkey-cards{display:grid; grid-template-columns:1fr 1.6fr 1fr 1.6fr; gap:32px; align-items:start;}
@media (max-width:900px){ .artkey-cards{grid-template-columns:1fr; gap:20px;} }
.artkey-text .card-label{font-size:11.5px; font-weight:700; letter-spacing:.16em; text-transform:uppercase; margin-bottom:14px; font-family:var(--sans);}
.artkey-text h3{font-family:var(--sans); font-size:clamp(20px,2.2vw,24px); font-weight:800; line-height:1.35; letter-spacing:-.015em; word-spacing:.18em; margin-bottom:12px;}
.artkey-text p{font-family:var(--sans); font-size:14.5px; line-height:1.75; color:var(--gray-soft); margin-bottom:20px;}
@media (max-width:900px){ .artkey-text{margin-bottom:12px;} }

/* ---------- footer ---------- */
footer{background:var(--ink); color:#fff; padding:80px 0 0;}
.foot-top{display:flex; justify-content:space-between; align-items:flex-start; flex-wrap:wrap; gap:36px; padding-bottom:56px;}
.foot-headline{
  font-family:var(--sans);
  font-weight:800; font-size:clamp(24px,3vw,32px); line-height:1.35;
  letter-spacing:-.02em; word-spacing:.18em; max-width:520px;
}
.foot-info{display:flex; flex-direction:column; gap:20px; max-width:420px;}
.fi-group{display:flex; flex-direction:column; gap:6px;}
.fi-line{font-family:var(--sans); font-size:13px; line-height:1.65; color:var(--muted);}
.fi-line .pipe{display:inline-block; margin:0 9px; color:#5C5C66;}
.fi-primary{font-size:14px; font-weight:600; color:#EDEDED;}
.foot-info a:hover{color:var(--corporate);}
.foot-bottom{
  padding:24px 0 28px; font-size:11.5px; font-weight:600; letter-spacing:.05em; color:#6E6E6E;
  display:flex; flex-direction:column; align-items:flex-end; gap:6px; font-family:var(--sans);
  text-align:right;
}
.ai-notice{
  font-family:var(--sans); font-size:10.5px; font-weight:500; color:#5C5C66;
}

/* ---------- contact page ---------- */
.contact-hero{
  background:var(--paper);
  padding:96px 0;
}
@media (max-width:680px){ .contact-hero{padding:64px 0;} }
.contact-grid{display:grid; grid-template-columns:repeat(3,1fr); gap:48px;}
@media (max-width:820px){ .contact-grid{grid-template-columns:1fr; gap:44px;} }
.contact-block h2{font-family:var(--sans); font-weight:800; font-size:clamp(26px,3vw,32px); line-height:1.2; letter-spacing:-.01em; margin-bottom:14px;}
.contact-tagline{font-family:var(--sans); font-size:13.5px; font-weight:600; color:var(--gray); margin-bottom:22px;}
.contact-rows{display:grid; grid-template-columns:76px 1fr; row-gap:10px; font-family:var(--sans); font-size:14px;}
.contact-rows .cap{font-weight:700; color:var(--ink);}
.contact-rows .val{color:var(--gray);}
.contact-rows .val a:hover{color:var(--corporate);}