/* ===========================================================
   공통 디자인 시스템 — 디지털 서비스 창업 / 바이브 마케팅
   색상은 전부 변수로만 쓴다. 과목별 강조색은 각 페이지에서
   :root 변수만 덮어쓰면 된다 (marketing.html 참고).
   =========================================================== */
:root{
  --bg:#0b0d12;
  --bg-soft:#11141c;
  --card:#161a24;
  --line:#242a38;
  --line-hover:#31394d;
  --text:#eef1f7;
  --muted:#9aa3b4;
  --dim:#5d6679;
  --accent:#6c7bff;
  --accent-alt:#8b7bff;
  --accent-2:#22d3a6;
  --accent-soft:rgba(108,123,255,.14);
  --accent-ink:#b9c0ff;
  --accent-border:rgba(108,123,255,.30);
  --btn-shadow:rgba(108,123,255,.28);
  --header-bg:rgba(11,13,18,.72);
  --soft-fill:rgba(255,255,255,.04);
  --shadow:0 30px 70px rgba(0,0,0,.45);
  --mark-bg:rgba(254,188,46,.16);
  --mark-ink:#febc2e;
  --glow-1:rgba(108,123,255,.28);
  --glow-2:rgba(34,211,166,.18);
  --cta-bg:linear-gradient(135deg,rgba(108,123,255,.16),rgba(34,211,166,.10));
  --cta-border:rgba(108,123,255,.25);
  --radius:16px;
  --max:1120px;
  color-scheme:dark;
}
:root[data-theme="light"]{
  --bg:#ffffff;
  --bg-soft:#f6f7fb;
  --card:#ffffff;
  --line:#e3e7f0;
  --line-hover:#c2c9da;
  --text:#101420;
  --muted:#596174;
  --dim:#98a0b2;
  --accent:#4a5bff;
  --accent-alt:#6b5bff;
  --accent-2:#0d9e7b;
  --accent-soft:rgba(74,91,255,.08);
  --accent-ink:#4a5bff;
  --accent-border:rgba(74,91,255,.28);
  --btn-shadow:rgba(74,91,255,.24);
  --header-bg:rgba(255,255,255,.8);
  --soft-fill:rgba(16,20,32,.04);
  --shadow:0 20px 50px rgba(16,20,32,.10);
  --mark-bg:rgba(180,83,9,.11);
  --mark-ink:#b45309;
  --glow-1:rgba(108,123,255,.16);
  --glow-2:rgba(34,211,166,.14);
  --cta-bg:linear-gradient(135deg,rgba(74,91,255,.10),rgba(13,158,123,.08));
  --cta-border:rgba(74,91,255,.22);
  color-scheme:light;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  background:var(--bg);
  color:var(--text);
  transition:background .3s ease,color .3s ease;
  font-family:"Pretendard Variable",Pretendard,-apple-system,BlinkMacSystemFont,system-ui,"Segoe UI",sans-serif;
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
img{max-width:100%}
.wrap{max-width:var(--max);margin:0 auto;padding:0 24px}

/* ── nav ─────────────────────────── */
header{
  position:sticky;top:0;z-index:50;
  backdrop-filter:blur(14px);
  background:var(--header-bg);
  border-bottom:1px solid transparent;
  transition:border-color .25s,background .3s ease;
}
header.scrolled{border-bottom-color:var(--line)}
.nav{display:flex;align-items:center;justify-content:space-between;height:66px;gap:16px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;letter-spacing:-.02em;white-space:nowrap}
.brand .dot{width:10px;height:10px;border-radius:3px;background:linear-gradient(135deg,var(--accent),var(--accent-2))}
.nav-links{display:flex;gap:28px;font-size:.92rem;color:var(--muted)}
.nav-links a:hover{color:var(--text)}
.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:12px 22px;border-radius:999px;font-weight:600;font-size:.94rem;
  border:1px solid transparent;transition:transform .15s,background .2s,border-color .2s;
}
.btn:hover{transform:translateY(-1px)}
.btn-primary{background:linear-gradient(135deg,var(--accent),var(--accent-alt));color:#fff;box-shadow:0 8px 28px var(--btn-shadow)}
.btn-ghost{border-color:var(--line);color:var(--text)}
.btn-ghost:hover{border-color:var(--accent);background:var(--accent-soft)}
.nav .btn{padding:9px 18px}
.nav-right{display:flex;align-items:center;gap:10px}

/* 과목 전환 스위처 */
.pages{display:flex;gap:4px;padding:4px;border-radius:999px;background:var(--soft-fill);border:1px solid var(--line)}
.pages a{
  padding:6px 14px;border-radius:999px;font-size:.85rem;font-weight:600;
  color:var(--muted);white-space:nowrap;transition:color .2s,background .2s;
}
.pages a:hover{color:var(--text)}
.pages a[aria-current="page"]{background:var(--card);color:var(--text);box-shadow:0 1px 3px rgba(0,0,0,.18)}

/* theme toggle */
.theme-toggle{
  width:38px;height:38px;flex:0 0 38px;
  display:grid;place-items:center;
  border-radius:50%;border:1px solid var(--line);
  background:var(--card);color:var(--muted);cursor:pointer;
  transition:color .2s,border-color .2s,background .2s,transform .15s;
}
.theme-toggle:hover{color:var(--text);border-color:var(--accent);background:var(--accent-soft);transform:translateY(-1px)}
.theme-toggle:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.theme-toggle svg{width:18px;height:18px;display:block}
.theme-toggle .i-sun{display:none}
:root[data-theme="light"] .theme-toggle .i-sun{display:block}
:root[data-theme="light"] .theme-toggle .i-moon{display:none}

/* ── hero ────────────────────────── */
.hero{position:relative;padding:104px 0 96px;overflow:hidden}
.hero::before{
  content:"";position:absolute;inset:-40% 0 auto -10%;height:720px;
  background:radial-gradient(45% 50% at 30% 40%,var(--glow-1),transparent 70%),
             radial-gradient(35% 45% at 75% 30%,var(--glow-2),transparent 70%);
  pointer-events:none;
}
.hero-inner{position:relative;display:grid;grid-template-columns:1.15fr .85fr;gap:56px;align-items:center}
.eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  padding:7px 14px;border-radius:999px;
  background:var(--accent-soft);border:1px solid var(--accent-border);
  color:var(--accent-ink);font-size:.82rem;font-weight:600;letter-spacing:.01em;
}
h1{
  font-size:clamp(2.2rem,5.2vw,3.5rem);line-height:1.18;letter-spacing:-.035em;
  margin:22px 0 18px;font-weight:800;
}
h1 .grad{background:linear-gradient(120deg,var(--accent),var(--accent-2));-webkit-background-clip:text;background-clip:text;color:transparent}
.lede{color:var(--muted);font-size:1.08rem;max-width:34em;margin-bottom:32px}
.hero-cta{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:34px}
.hero-meta{display:flex;gap:30px;flex-wrap:wrap;font-size:.88rem;color:var(--muted)}
.hero-meta b{display:block;color:var(--text);font-size:1.28rem;font-weight:700;letter-spacing:-.02em}

/* terminal / chat card */
.term{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  box-shadow:var(--shadow);overflow:hidden;font-size:.85rem;
}
.term-bar{display:flex;gap:7px;padding:13px 16px;border-bottom:1px solid var(--line);background:var(--soft-fill)}
.term-bar i{width:11px;height:11px;border-radius:50%;background:var(--line)}
.term-bar i:first-child{background:#ff5f57}.term-bar i:nth-child(2){background:#febc2e}.term-bar i:nth-child(3){background:#28c840}
.term-body{padding:20px;font-family:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,monospace;line-height:1.85;color:var(--muted)}
.term-body .p{color:var(--accent-2)}
.term-body .c{color:var(--text)}
.term-body .k{color:var(--accent-ink)}
.term-body .dim{color:var(--dim)}
.cursor{display:inline-block;width:8px;height:1em;background:var(--accent-2);vertical-align:-2px;animation:blink 1.1s step-end infinite}
@keyframes blink{50%{opacity:0}}

/* ── sections ────────────────────── */
section{padding:92px 0}
.sec-head{max-width:40em;margin-bottom:48px}
.sec-tag{color:var(--accent-2);font-weight:700;font-size:.85rem;letter-spacing:.06em;text-transform:uppercase}
h2{font-size:clamp(1.7rem,3.4vw,2.35rem);letter-spacing:-.03em;margin:12px 0 14px;font-weight:800;line-height:1.28}
.sec-head p{color:var(--muted);margin:0}
.alt{background:var(--bg-soft);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}

.grid{display:grid;gap:20px}
.g2{grid-template-columns:repeat(2,1fr)}
.g3{grid-template-columns:repeat(3,1fr)}
.g4{grid-template-columns:repeat(4,1fr)}
.card{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:28px;transition:border-color .2s,transform .2s;
}
.card:hover{border-color:var(--line-hover);transform:translateY(-3px)}
.card .ico{
  width:42px;height:42px;border-radius:11px;display:grid;place-items:center;
  background:var(--accent-soft);color:var(--accent-ink);font-size:1.15rem;margin-bottom:16px;
}
.card h3{margin:0 0 8px;font-size:1.06rem;letter-spacing:-.02em}
.card p{margin:0;color:var(--muted);font-size:.93rem}

/* before / after */
.probs{display:grid;grid-template-columns:1fr 1fr;gap:20px;align-items:start}
.prob{padding:26px 28px;border-radius:var(--radius);border:1px solid var(--line)}
.prob.before{background:rgba(255,95,87,.05);border-color:rgba(255,95,87,.22)}
.prob.after{background:rgba(34,211,166,.05);border-color:rgba(34,211,166,.22)}
.prob h4{margin:0 0 14px;font-size:.84rem;letter-spacing:.06em;text-transform:uppercase;color:var(--muted)}
.prob ul{margin:0;padding-left:20px;color:var(--muted);font-size:.95rem}
.prob li{margin-bottom:9px}
.prob.after li{color:var(--text)}

/* curriculum */
.weeks{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}
.week{
  display:flex;gap:18px;padding:20px 22px;border-radius:14px;
  background:var(--card);border:1px solid var(--line);transition:border-color .2s;
}
.week:hover{border-color:var(--accent)}
.week .no{
  flex:0 0 46px;height:46px;border-radius:12px;display:grid;place-items:center;
  background:var(--soft-fill);border:1px solid var(--line);
  font-weight:700;font-size:.9rem;color:var(--accent-ink);
}
.week h4{margin:0 0 4px;font-size:1rem;letter-spacing:-.02em}
.week p{margin:0;color:var(--muted);font-size:.89rem}
.phase{
  grid-column:1/-1;display:flex;align-items:center;gap:14px;margin-top:22px;
  font-size:.82rem;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--accent-2);
}
.phase:first-child{margin-top:0}
.phase::after{content:"";flex:1;height:1px;background:var(--line)}

/* stack */
.stack{display:flex;flex-wrap:wrap;gap:12px}
.chip{
  padding:11px 20px;border-radius:999px;border:1px solid var(--line);
  background:var(--card);font-size:.92rem;color:var(--muted);transition:.2s;
}
.chip:hover{color:var(--text);border-color:var(--accent);background:var(--accent-soft)}

/* 산출물 체크리스트 */
.deliver{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}
.deliver div{
  display:flex;gap:14px;align-items:flex-start;
  padding:18px 22px;border-radius:14px;background:var(--card);border:1px solid var(--line);
}
.deliver .tick{
  flex:0 0 22px;height:22px;margin-top:2px;border-radius:50%;
  background:var(--accent-soft);color:var(--accent-ink);
  display:grid;place-items:center;font-size:.72rem;font-weight:700;
}
.deliver b{display:block;font-size:.98rem;letter-spacing:-.01em}
.deliver span{color:var(--muted);font-size:.88rem}

/* info table */
.info{display:grid;grid-template-columns:repeat(2,1fr);gap:0;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden}
.info div{padding:22px 26px;border-bottom:1px solid var(--line)}
.info div:nth-child(odd){border-right:1px solid var(--line)}
.info div:nth-last-child(-n+2){border-bottom:none}
.info dt{margin:0 0 6px;font-size:.84rem;color:var(--muted)}
.info dd{margin:0;font-weight:600;letter-spacing:-.01em}
mark{background:var(--mark-bg);color:var(--mark-ink);padding:1px 7px;border-radius:5px;font-weight:600}

/* faq */
.faq{max-width:780px}
details{border-bottom:1px solid var(--line);padding:20px 0}
summary{
  cursor:pointer;list-style:none;font-weight:600;letter-spacing:-.01em;
  display:flex;justify-content:space-between;gap:16px;align-items:center;
}
summary::-webkit-details-marker{display:none}
summary::after{content:"+";color:var(--accent);font-size:1.4rem;line-height:1;transition:transform .2s}
details[open] summary::after{transform:rotate(45deg)}
details p{color:var(--muted);margin:14px 0 0;font-size:.95rem}

/* 다른 과목 안내 배너 */
.sibling{
  display:flex;align-items:center;justify-content:space-between;gap:24px;flex-wrap:wrap;
  padding:30px 34px;border-radius:var(--radius);
  background:var(--card);border:1px solid var(--line);
}
.sibling h3{margin:0 0 6px;font-size:1.12rem;letter-spacing:-.02em}
.sibling p{margin:0;color:var(--muted);font-size:.93rem}

/* cta */
.cta{
  text-align:center;padding:70px 32px;border-radius:24px;
  background:var(--cta-bg);
  border:1px solid var(--cta-border);
}
.cta h2{margin-top:0}
.cta p{color:var(--muted);max-width:32em;margin:0 auto 30px}
.cta-btns{display:flex;gap:12px;justify-content:center;flex-wrap:wrap}

footer{border-top:1px solid var(--line);padding:38px 0;color:var(--muted);font-size:.88rem}
.foot{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}
.foot a:hover{color:var(--text)}

/* 테마 전환 시 표면 색이 부드럽게 따라오도록 */
.card,.week,.chip,.term,.info,.prob,.theme-toggle,.btn-ghost,details,.sibling,.deliver div,.pages{
  transition-property:background-color,border-color,color,transform,box-shadow;
  transition-duration:.3s;
}

/* reveal */
.rv{opacity:0;transform:translateY(18px);transition:opacity .6s ease,transform .6s ease}
.rv.in{opacity:1;transform:none}

@media(max-width:900px){
  .hero-inner{grid-template-columns:1fr;gap:40px}
  .g2,.g3,.g4,.weeks,.probs,.info,.deliver{grid-template-columns:1fr}
  .info div:nth-child(odd){border-right:none}
  .info div:nth-last-child(2){border-bottom:1px solid var(--line)}
  .nav-links{display:none}
  section{padding:68px 0}
  .hero{padding:72px 0 64px}
}
@media(max-width:560px){
  .brand .label{display:none}
  .nav .btn{display:none}
  .pages a{padding:6px 11px;font-size:.8rem}
}