:root{
  --bg:#0d1017; --bg2:#12161f; --bg3:#1a1f2b; --border:#242b39;
  --text:#e7ecf3; --muted:#93a0b4; --accent:#4c9aff; --accent2:#7c5cff; --ok:#3fb950;
  --radius:12px; --wrap:1080px;
  --font:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue","Malgun Gothic","Apple SD Gothic Neo","Noto Sans KR","Noto Sans JP","Yu Gothic",Meiryo,sans-serif;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{background:var(--bg);color:var(--text);font-family:var(--font);line-height:1.65;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.wrap{max-width:var(--wrap);margin:0 auto;padding:0 22px}
.wrap.narrow{max-width:760px}

/* header */
.site-header{position:sticky;top:0;z-index:50;background:rgba(13,16,23,.82);backdrop-filter:blur(10px);border-bottom:1px solid var(--border)}
.header-inner{display:flex;align-items:center;gap:18px;height:60px}
.brand{display:flex;align-items:center;gap:8px;font-weight:700;letter-spacing:.2px}
.brand-mark{background:linear-gradient(135deg,var(--accent),var(--accent2));color:#fff;font-size:12px;font-weight:800;padding:3px 7px;border-radius:7px}
.brand-name{color:var(--text)}
.brand.small .brand-mark{font-size:11px}
.nav{display:flex;gap:20px;margin-left:auto;font-size:14px}
.nav a{color:var(--muted);transition:color .15s}
.nav a:hover{color:var(--text)}
.nav a.nav-guide{color:var(--accent)}
.lang{display:flex;gap:4px;margin-left:8px}
.lang button{background:transparent;border:1px solid var(--border);color:var(--muted);font-size:11px;font-weight:600;padding:4px 8px;border-radius:6px;cursor:pointer;transition:all .15s}
.lang button:hover{color:var(--text);border-color:var(--accent)}
.lang button.active{background:var(--accent);border-color:var(--accent);color:#fff}

/* hero */
.hero{position:relative;padding:76px 0 54px;text-align:center;background:radial-gradient(1200px 400px at 50% -80px,rgba(76,154,255,.16),transparent 70%),radial-gradient(900px 380px at 80% 0,rgba(124,92,255,.12),transparent 70%)}
.hero-inner{display:flex;flex-direction:column;align-items:center}
.badge{display:inline-block;background:var(--bg3);border:1px solid var(--border);color:var(--muted);font-size:12px;font-weight:600;padding:5px 12px;border-radius:999px;margin-bottom:20px}
.hero h1{font-size:clamp(30px,5vw,48px);line-height:1.15;font-weight:800;letter-spacing:-.5px;max-width:14ch}
.lead{color:var(--muted);font-size:clamp(15px,2vw,18px);max-width:60ch;margin:18px auto 0}
.cta-row{display:flex;gap:12px;margin-top:26px;flex-wrap:wrap;justify-content:center}
.btn{display:inline-block;font-weight:600;font-size:15px;padding:12px 22px;border-radius:10px;cursor:pointer;border:1px solid transparent;transition:transform .12s,background .15s,border-color .15s}
.btn:hover{transform:translateY(-1px)}
.btn-primary{background:var(--accent);color:#fff}
.btn-primary:hover{background:#3d8bf5}
.btn-ghost{background:transparent;border-color:var(--border);color:var(--text)}
.btn-ghost:hover{border-color:var(--accent)}
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin-top:44px;width:100%;max-width:760px}
.stat{background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius);padding:18px 12px}
.stat-value{font-size:22px;font-weight:800;color:var(--text)}
.stat-label{font-size:12px;color:var(--muted);margin-top:4px}

/* sections */
.section{padding:66px 0}
.section.alt{background:var(--bg2);border-top:1px solid var(--border);border-bottom:1px solid var(--border)}
.section-title{font-size:clamp(22px,3.4vw,30px);font-weight:800;letter-spacing:-.3px;text-align:center}
.section-sub{color:var(--muted);text-align:center;max-width:60ch;margin:12px auto 0}

/* why */
.why-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:36px}
.why-card{background:var(--bg3);border:1px solid var(--border);border-radius:var(--radius);padding:22px}
.why-icon{font-size:24px;margin-bottom:10px}
.why-card h3{font-size:16px;margin-bottom:6px}
.why-card p{color:var(--muted);font-size:14px}

/* feature groups */
.feature-groups{display:grid;grid-template-columns:repeat(2,1fr);gap:18px;margin-top:38px}
.fg-col{background:var(--bg3);border:1px solid var(--border);border-radius:var(--radius);padding:22px}
.fg-head{display:flex;align-items:center;gap:10px;margin-bottom:14px;padding-bottom:12px;border-bottom:1px solid var(--border)}
.fg-icon{font-size:22px}
.fg-title{font-size:17px;font-weight:700}
.fg-item{padding:9px 0;border-bottom:1px dashed rgba(148,160,180,.14)}
.fg-item:last-child{border-bottom:none}
.fg-item-title{font-size:14px;font-weight:600;color:var(--text)}
.fg-item-body{font-size:13px;color:var(--muted);margin-top:2px}

/* how */
.how-steps{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-top:38px;counter-reset:step}
.step{background:var(--bg3);border:1px solid var(--border);border-radius:var(--radius);padding:22px;position:relative}
.step-n{width:34px;height:34px;border-radius:50%;background:linear-gradient(135deg,var(--accent),var(--accent2));color:#fff;font-weight:800;display:flex;align-items:center;justify-content:center;margin-bottom:12px}
.step-title{font-size:15px;font-weight:700;margin-bottom:5px}
.step-body{font-size:13px;color:var(--muted)}

/* gallery */
.gallery{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:36px}
.shot{background:var(--bg3);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden;cursor:zoom-in;transition:border-color .15s,transform .12s}
.shot:hover{border-color:var(--accent);transform:translateY(-2px)}
.shot img{width:100%;aspect-ratio:16/10;object-fit:cover;background:var(--bg)}
.shot figcaption{font-size:12px;color:var(--muted);padding:10px 12px}

/* compat */
.compat-wrap{display:grid;grid-template-columns:1fr 1.3fr;gap:18px;margin-top:34px}
.compat-boxes{background:var(--bg3);border:1px solid var(--border);border-radius:var(--radius);padding:22px}
.compat-boxes-label{font-size:13px;color:var(--muted);margin-bottom:12px}
.chip-row{display:flex;flex-wrap:wrap;gap:8px}
.chip{background:var(--bg);border:1px solid var(--border);color:var(--text);font-size:13px;font-weight:600;padding:6px 12px;border-radius:8px}
.compat-table{width:100%;border-collapse:collapse;background:var(--bg3);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden}
.compat-table th,.compat-table td{text-align:left;padding:12px 16px;font-size:14px;border-bottom:1px solid var(--border)}
.compat-table th{color:var(--muted);font-weight:600;width:34%;white-space:nowrap}
.compat-table tr:last-child th,.compat-table tr:last-child td{border-bottom:none}
.note{color:var(--muted);font-size:12.5px;margin-top:16px;text-align:center}

/* download */
.dl-meta{display:flex;gap:22px;justify-content:center;margin-top:26px;color:var(--muted);font-size:14px}
.dl-meta strong{color:var(--text)}
.dl-cards{display:grid;grid-template-columns:repeat(2,1fr);gap:16px;margin-top:22px}
.dl-card{background:var(--bg3);border:1px solid var(--border);border-radius:var(--radius);padding:22px;transition:border-color .15s,transform .12s}
.dl-card:hover{border-color:var(--accent);transform:translateY(-2px)}
.dl-card-title{font-size:16px;font-weight:700;color:var(--accent)}
.dl-card-desc{font-size:13px;color:var(--muted);margin-top:6px}
.dl-card-file{font-size:12px;color:var(--muted);margin-top:10px;font-family:ui-monospace,Consolas,monospace;word-break:break-all}
.dl-cols{display:grid;grid-template-columns:1fr 1fr;gap:22px;margin-top:26px}
.mini-title{font-size:14px;font-weight:700;margin-bottom:10px}
.ticklist,.notelist{list-style:none}
.ticklist li,.notelist li{font-size:13.5px;color:var(--muted);padding:5px 0 5px 22px;position:relative}
.ticklist li:before{content:"✓";color:var(--ok);position:absolute;left:0;font-weight:800}
.notelist li:before{content:"›";color:var(--accent);position:absolute;left:6px}
.guide-cta{text-align:center;margin-top:24px}
.guide-cta a{color:var(--accent);font-weight:600;font-size:14px}

/* faq */
.faq{margin-top:28px;display:flex;flex-direction:column;gap:10px}
.faq-item{background:var(--bg3);border:1px solid var(--border);border-radius:10px;overflow:hidden}
.faq-item summary{cursor:pointer;padding:15px 18px;font-weight:600;font-size:15px;list-style:none}
.faq-item summary::-webkit-details-marker{display:none}
.faq-item summary:before{content:"+";color:var(--accent);font-weight:800;margin-right:10px}
.faq-item[open] summary:before{content:"−"}
.faq-a{padding:0 18px 16px;color:var(--muted);font-size:14px}

/* contact */
.contact-form{margin-top:26px;display:flex;flex-direction:column;gap:12px}
.field-row{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.contact-form input,.contact-form textarea{background:var(--bg);border:1px solid var(--border);border-radius:9px;color:var(--text);font-family:inherit;font-size:14px;padding:12px 14px;width:100%}
.contact-form input:focus,.contact-form textarea:focus{outline:none;border-color:var(--accent)}
.contact-form .btn{align-self:flex-start}
.form-status{font-size:13px;min-height:18px}
.form-status.ok{color:var(--ok)}
.form-status.err{color:#f47272}

/* footer */
.site-footer{border-top:1px solid var(--border);background:var(--bg2);padding:34px 0 26px}
.footer-inner{display:flex;justify-content:space-between;gap:20px;flex-wrap:wrap;align-items:flex-start}
.foot-tag{color:var(--muted);font-size:13px;margin-top:8px}
.foot-links{display:flex;gap:18px;font-size:14px}
.foot-links a{color:var(--muted)}
.foot-links a:hover{color:var(--text)}
.rights{color:var(--muted);font-size:12px;margin-top:22px;padding-top:18px;border-top:1px solid var(--border)}

/* guide page */
.guide-hero{padding:54px 0 20px;background:radial-gradient(900px 300px at 30% -60px,rgba(76,154,255,.14),transparent 70%)}
.guide-hero h1{font-size:clamp(26px,4vw,38px);font-weight:800}
.guide-hero .lead{margin-left:0;text-align:left}
.guide-layout{display:grid;grid-template-columns:220px 1fr;gap:34px;align-items:start}
.guide-toc{position:sticky;top:80px}
.toc-title{font-size:12px;text-transform:uppercase;letter-spacing:.6px;color:var(--muted);margin-bottom:12px}
#guide-toc{display:flex;flex-direction:column;gap:8px}
#guide-toc a{color:var(--muted);font-size:14px;padding:4px 0;border-left:2px solid transparent;padding-left:10px;transition:all .15s}
#guide-toc a:hover{color:var(--text);border-left-color:var(--accent)}
.guide-section{background:var(--bg3);border:1px solid var(--border);border-radius:var(--radius);padding:24px;margin-bottom:16px;scroll-margin-top:80px}
.guide-h{font-size:18px;font-weight:700;margin-bottom:14px}
.guide-steps{margin:0;padding-left:20px;display:flex;flex-direction:column;gap:10px}
.guide-steps li{color:var(--muted);font-size:14px;padding-left:4px}
.guide-back{display:inline-block;margin-top:6px;color:var(--accent);font-weight:600;font-size:14px}

/* lightbox */
.lightbox{position:fixed;inset:0;z-index:100;background:rgba(0,0,0,.85);display:flex;align-items:center;justify-content:center;padding:30px}
.lightbox[hidden]{display:none}
.lightbox img{max-width:92vw;max-height:88vh;border-radius:10px;border:1px solid var(--border)}
.lightbox-close{position:absolute;top:18px;right:22px;background:var(--bg3);border:1px solid var(--border);color:var(--text);font-size:16px;width:38px;height:38px;border-radius:9px;cursor:pointer}

/* responsive */
@media (max-width:920px){
  .feature-groups,.dl-cols,.compat-wrap{grid-template-columns:1fr}
  .how-steps{grid-template-columns:repeat(2,1fr)}
  .guide-layout{grid-template-columns:1fr}
  .guide-toc{position:static;display:none}
}
@media (max-width:640px){
  .nav{display:none}
  .stats{grid-template-columns:repeat(2,1fr)}
  .why-grid,.gallery,.dl-cards{grid-template-columns:1fr}
  .how-steps{grid-template-columns:1fr}
  .field-row{grid-template-columns:1fr}
  .header-inner{gap:10px}
}

.shot-hidden{display:none}

/* contact — direct email (no backend form) */
.contact-box{margin-top:26px;background:var(--bg3);border:1px solid var(--border);border-radius:var(--radius);padding:26px;text-align:center}
.contact-mail{display:inline-block;font-size:15px}
.contact-addr{margin-top:16px;font-size:14px;color:var(--muted)}
.contact-addr-label{margin-right:8px}
.contact-email{color:var(--accent);font-weight:600}
.contact-email:hover{text-decoration:underline}
.dl-req-block{margin-top:26px;max-width:520px}

/* installer-only download (no portable) */
.dl-cards-single{grid-template-columns:1fr;max-width:520px;margin-left:auto;margin-right:auto}