:root{
  --ink:#16284A; --ink2:#22386B; --blue:#2E6FD6; --blue2:#5B8FE0;
  --soft:#DCE9FB; --tint:#F1F6FE; --gray:#6B7280; --line:#E3ECF7; --bg:#fff;
  --maxw:1120px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:'Pretendard',-apple-system,'Malgun Gothic','Apple SD Gothic Neo',sans-serif;
  color:var(--ink); background:var(--bg); line-height:1.6;
  -webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none}
b{font-weight:700}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px}
.center{text-align:center}
.muted{color:var(--gray)}
.small{font-size:.85rem}

/* NAV */
.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.82);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.nav-inner{max-width:var(--maxw);margin:0 auto;padding:14px 24px;display:flex;align-items:center;justify-content:space-between}
.brand{font-weight:800;font-size:1.05rem;color:var(--ink)}
.nav-links{display:flex;gap:26px}
.nav-links a{color:var(--gray);font-weight:600;font-size:.95rem;transition:color .15s}
.nav-links a:hover{color:var(--blue)}

/* HERO */
.hero{background:var(--ink);color:#fff;padding:96px 24px 84px;text-align:center;position:relative;overflow:hidden}
.hero-inner{max-width:860px;margin:0 auto}
.eyebrow{color:#7FB0EE;font-weight:700;letter-spacing:.18em;font-size:.8rem;margin-bottom:22px}
.hero h1{font-size:clamp(2.6rem,8vw,4.6rem);font-weight:800;letter-spacing:-.02em;line-height:1.05}
.hero-sub{color:#BFD6F5;font-size:clamp(1.1rem,3.2vw,1.6rem);font-weight:600;margin-top:18px}
.hero-lead{color:#9FC0EA;margin-top:26px;font-size:clamp(.95rem,2.4vw,1.1rem)}
.hero-cta{margin-top:38px;display:flex;gap:14px;justify-content:center;flex-wrap:wrap}
.btn{display:inline-block;padding:13px 26px;border-radius:999px;font-weight:700;font-size:.98rem;transition:transform .12s,box-shadow .15s,background .15s}
.btn:active{transform:translateY(1px)}
.btn-primary{background:var(--blue);color:#fff;box-shadow:0 8px 22px rgba(46,111,214,.35)}
.btn-primary:hover{background:#2a63bf}
.btn-ghost{background:transparent;color:#cfe0fb;border:1.5px solid #3A5A8A}
.btn-ghost:hover{border-color:#7FB0EE;color:#fff}
.btn.sm{padding:9px 18px;font-size:.88rem}
.thread{display:flex;align-items:center;justify-content:center;gap:0;margin-top:54px}
.thread span{width:18px;height:18px;border-radius:50%;background:var(--blue);flex:0 0 auto}
.thread i{height:2px;width:min(9vw,64px);background:#3A5A8A;display:block}
.thread-labels{display:flex;justify-content:center;gap:min(9vw,64px);list-style:none;margin-top:12px}
.thread-labels li{color:#7FA8DC;font-size:.78rem;width:18px;text-align:center;white-space:nowrap;transform:translateX(-50%);margin-left:9px}
@media(max-width:560px){.thread-labels{display:none}}

/* SECTIONS */
.section{padding:84px 0}
.section.alt{background:var(--tint)}
.kicker{color:var(--blue);font-weight:800;letter-spacing:.12em;font-size:.82rem;text-transform:uppercase}
.section h2{font-size:clamp(1.6rem,4.5vw,2.5rem);font-weight:800;letter-spacing:-.01em;margin-top:10px}
.lead{color:var(--gray);font-size:clamp(1rem,2.4vw,1.18rem);margin-top:14px;max-width:680px}
.center .lead{margin-left:auto;margin-right:auto}

/* ABOUT cards */
.cards-3{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin-top:42px}
.card{background:#fff;border:1px solid var(--line);border-radius:18px;padding:30px 26px;box-shadow:0 8px 26px rgba(22,40,74,.06);position:relative}
.card .num{display:inline-flex;align-items:center;justify-content:center;width:42px;height:42px;border-radius:12px;background:var(--blue);color:#fff;font-weight:800;font-size:1.1rem;margin-bottom:16px}
.card h3{font-size:1.12rem;font-weight:700;margin-bottom:10px}
.card p{color:var(--gray);font-size:.96rem}
.offer{margin-top:48px;background:var(--ink);color:#fff;border-radius:22px;padding:38px 34px;text-align:center}
.offer>p:first-child{color:#BFD6F5;font-size:1.05rem}
.offer-row{display:flex;gap:18px;justify-content:center;margin:22px 0;flex-wrap:wrap}
.offer-item{background:rgba(127,176,238,.12);border:1px solid #2f4a7e;border-radius:16px;padding:20px 26px;min-width:230px}
.offer-item b{display:block;color:#7FB0EE;font-size:1.2rem;margin-bottom:4px}
.offer-item span{color:#cdddf5;font-size:.92rem}
.offer .muted{color:#8FAAD0;font-size:.9rem}

/* VIEWER */
.viewer{display:flex;align-items:center;gap:14px;margin-top:36px}
.stage{flex:1;border-radius:16px;overflow:hidden;box-shadow:0 18px 50px rgba(22,40,74,.16);background:#fff;aspect-ratio:16/9}
.stage img{display:block;width:100%;height:100%;object-fit:contain;background:#fff}
.nav-btn{flex:0 0 auto;width:50px;height:50px;border-radius:50%;border:none;background:#fff;color:var(--blue);font-size:1.7rem;line-height:1;cursor:pointer;box-shadow:0 6px 18px rgba(22,40,74,.12);transition:background .15s,transform .12s}
.nav-btn:hover{background:var(--blue);color:#fff}
.nav-btn:active{transform:scale(.94)}
.viewer-bar{display:flex;align-items:center;gap:18px;margin-top:20px;flex-wrap:wrap;justify-content:center}
.counter{color:var(--gray);font-weight:600}
.counter b{color:var(--ink)}
.dots{display:flex;gap:7px;flex-wrap:wrap;justify-content:center;flex:1}
.dot{width:9px;height:9px;border-radius:50%;background:var(--soft);cursor:pointer;transition:background .15s,transform .15s}
.dot.on{background:var(--blue);transform:scale(1.25)}

/* FOOTER */
.foot{background:var(--ink);color:#cfe0fb;text-align:center;padding:40px 24px}
.foot .muted{color:#7FA8DC}

/* RESPONSIVE */
@media(max-width:860px){
  .cards-3{grid-template-columns:1fr}
  .nav-links{gap:18px}
}
@media(max-width:600px){
  .section{padding:60px 0}
  .hero{padding:72px 20px 64px}
  .nav-links a{font-size:.88rem}
  .nav-btn{width:42px;height:42px;font-size:1.4rem}
  .dots{order:3;flex-basis:100%}
  .offer{padding:30px 22px}
}