/* ============================================================
   OPDADA · Korea Guide — shared styles (self-contained)
   Change brand/colors via the :root variables below.
   ============================================================ */
:root{
  --bg:#ffffff; --card:#ffffff; --ink:#1a1a1f; --sub:#6a6a72;
  --line:#ececf0; --accent:#2f6bff; --accent-ink:#ffffff;
  --brand-grad:linear-gradient(135deg,#3a3a3d,#0e0e10);
  --maxw:1080px; --radius:16px;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  line-height:1.65;font-size:16px;-webkit-font-smoothing:antialiased}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;height:auto}
.container{max-width:var(--maxw);margin:0 auto;padding:0 20px}

/* header */
.nav{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.9);
  backdrop-filter:saturate(180%) blur(10px);border-bottom:1px solid var(--line)}
.nav-inner{display:flex;align-items:center;gap:18px;height:60px;max-width:var(--maxw);margin:0 auto;padding:0 20px}
.brand{font-weight:800;font-size:19px;letter-spacing:-.02em;color:var(--ink)}
.brand span{background:var(--brand-grad);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.nav-links{margin-left:auto;display:flex;gap:20px;font-size:14.5px;font-weight:600}
.nav-links a{color:var(--sub)}
.nav-links a:hover{color:var(--ink);text-decoration:none}

/* hero */
.hero{padding:64px 0 44px;text-align:center;background:
  radial-gradient(1200px 400px at 50% -10%, #f3f6ff 0%, transparent 70%)}
.hero h1{font-size:clamp(30px,5vw,48px);line-height:1.12;letter-spacing:-.03em;margin:0 0 16px;font-weight:850}
.hero p{max-width:640px;margin:0 auto;color:var(--sub);font-size:18px}
.hero .cta{margin-top:26px;display:inline-flex;gap:12px;flex-wrap:wrap;justify-content:center}
.btn{display:inline-block;padding:13px 24px;border-radius:12px;font-weight:700;font-size:15px}
.btn.primary{background:var(--brand-grad);color:#fff}
.btn.ghost{background:#fff;color:var(--ink);border:1px solid var(--line)}
.btn:hover{text-decoration:none;transform:translateY(-1px)}

/* sections */
section{padding:40px 0}
.section-title{font-size:24px;font-weight:800;letter-spacing:-.02em;margin:0 0 6px}
.section-sub{color:var(--sub);margin:0 0 22px}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:16px}
.card{display:block;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:22px;transition:box-shadow .15s,transform .15s}
.card:hover{text-decoration:none;box-shadow:0 8px 30px rgba(20,20,40,.08);transform:translateY(-2px)}
.card .emoji{font-size:26px}
.card h3{margin:10px 0 6px;font-size:17.5px;color:var(--ink);letter-spacing:-.01em}
.card p{margin:0;color:var(--sub);font-size:14px}
.tools .card h3{font-size:16px}

/* article */
.article{max-width:760px;margin:0 auto;padding:32px 20px 10px}
.article h1{font-size:clamp(26px,4vw,36px);line-height:1.2;letter-spacing:-.02em;margin:0 0 8px}
.article .meta{color:var(--sub);font-size:14px;margin:0 0 26px}
.article h2{font-size:21px;margin:34px 0 10px;letter-spacing:-.01em}
.article p,.article li{font-size:16.5px;color:#28282e}
.article ul{padding-left:22px}
.article li{margin:6px 0}
.callout{background:#f5f8ff;border:1px solid #e3ecff;border-radius:12px;padding:16px 18px;margin:22px 0}
.callout b{color:var(--accent)}
.embed-wrap{border:1px solid var(--line);border-radius:14px;overflow:hidden;margin:20px 0}
.embed-wrap iframe{display:block;width:100%;border:0}

/* footer */
footer{border-top:1px solid var(--line);margin-top:40px;padding:30px 0;color:var(--sub);font-size:13.5px}
footer a{color:var(--sub)}
.disclaimer{font-size:12.5px;color:#9a9aa2;margin-top:8px}

@media (max-width:640px){
  .hero{padding:44px 0 30px}
  .nav-links{gap:14px}
}