/* Findex advanced guide — shared styles (ko/en bilingual, light/dark) */
*{box-sizing:border-box}
:root{
  --bg:#fff;--surface:#fff;--surface-2:#f7f8fb;--surface-3:#eef2f7;
  --nav-bg:rgba(255,255,255,.88);--ink:#101218;--ink-2:#252936;
  --muted:#636b78;--muted-strong:#48505f;--border:#e1e5ec;
  --primary:#5735f0;--primary-2:#0f766e;--blue:#2563eb;--amber:#b45309;--green:#0f8a4b;--red:#c0392b;
  --shadow:0 18px 48px -32px rgba(20,24,40,.38);
  --shot-border:#d7dbe4;
}
:root[data-theme="dark"]{
  --bg:#11131a;--surface:#191c25;--surface-2:#151821;--surface-3:#202432;
  --nav-bg:rgba(17,19,26,.88);--ink:#f2f4f8;--ink-2:#d6dae3;
  --muted:#a0a7b4;--muted-strong:#c1c7d2;--border:#343947;
  --primary:#8a7bff;--primary-2:#40b8a2;--blue:#77a6ff;--amber:#f3b85c;--green:#5bd38a;--red:#ef8d7d;
  --shadow:0 18px 48px -30px rgba(0,0,0,.66);
  --shot-border:#3a4050;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --bg:#11131a;--surface:#191c25;--surface-2:#151821;--surface-3:#202432;
    --nav-bg:rgba(17,19,26,.88);--ink:#f2f4f8;--ink-2:#d6dae3;
    --muted:#a0a7b4;--muted-strong:#c1c7d2;--border:#343947;
    --primary:#8a7bff;--primary-2:#40b8a2;--blue:#77a6ff;--amber:#f3b85c;--green:#5bd38a;--red:#ef8d7d;
    --shadow:0 18px 48px -30px rgba(0,0,0,.66);
    --shot-border:#3a4050;
  }
}
html,body{margin:0;padding:0;background:var(--bg);color:var(--ink);font-family:Pretendard,system-ui,-apple-system,"Segoe UI",sans-serif;-webkit-font-smoothing:antialiased}
html{scroll-behavior:smooth}
a{color:inherit}
img{display:block;max-width:100%;height:auto}
code{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.94em;background:var(--surface-3);border-radius:5px;padding:1px 5px}
.brand-logo-img{filter:none;height:24px;width:auto}
:root[data-theme="dark"] .brand-logo-img{filter:brightness(0) invert(1)}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .brand-logo-img{filter:brightness(0) invert(1)}}

/* language visibility: html[lang] hides the other language */
html[lang="ko"] [data-lang="en"]{display:none!important}
html[lang="en"] [data-lang="ko"]{display:none!important}
/* keep Korean words unbroken in headings/leads */
html[lang="ko"] h1,html[lang="ko"] h2,html[lang="ko"] h3,html[lang="ko"] .lead{word-break:keep-all}

/* ---------- top nav ---------- */
.nav{position:sticky;top:0;z-index:40;display:flex;align-items:center;justify-content:space-between;gap:14px;padding:12px 26px;background:var(--nav-bg);border-bottom:1px solid var(--border);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px)}
.nav-left{display:flex;align-items:center;gap:20px;min-width:0}
.nav-links{display:flex;align-items:center;gap:4px;overflow-x:auto;scrollbar-width:none}
.nav-links::-webkit-scrollbar{display:none}
.nav-links a{font-size:13.5px;color:var(--muted);text-decoration:none;padding:7px 10px;border-radius:8px;white-space:nowrap}
.nav-links a:hover{color:var(--ink);background:var(--surface-2)}
.nav-links a.active{color:var(--primary);font-weight:800;background:color-mix(in srgb,var(--primary) 9%,transparent)}
.nav-right{display:flex;align-items:center;gap:9px;flex-shrink:0}
.nav-right .home-link{font-size:13px;color:var(--muted);text-decoration:none;white-space:nowrap}
.nav-right .home-link:hover{color:var(--ink)}
.lang-switch{display:inline-flex;border:1px solid var(--border);border-radius:8px;overflow:hidden}
.lang-switch button{border:0;background:var(--surface);color:var(--muted);font:700 12px Pretendard,system-ui,sans-serif;padding:8px 11px;cursor:pointer}
.lang-switch button.active{background:var(--primary);color:#fff}
.theme-toggle{display:inline-flex;align-items:center;justify-content:center;width:34px;height:34px;border:1px solid var(--border);border-radius:8px;background:var(--surface);color:var(--ink-2);cursor:pointer}

/* ---------- layout ---------- */
.wrap{max-width:1180px;margin:0 auto;padding:0 26px}
.hero{padding:46px 0 8px}
.eyebrow{display:inline-flex;align-items:center;gap:8px;margin-bottom:13px;font-size:12.5px;font-weight:800;color:var(--primary);background:color-mix(in srgb,var(--primary) 10%,transparent);border:1px solid color-mix(in srgb,var(--primary) 24%,transparent);border-radius:999px;padding:6px 12px}
h1{margin:0;font-size:38px;line-height:1.16;font-weight:850;letter-spacing:0;text-wrap:balance}
.lead{max-width:820px;margin:14px 0 0;font-size:16.5px;line-height:1.72;color:var(--muted)}
.layout{display:grid;grid-template-columns:216px minmax(0,1fr);gap:36px;padding:34px 0 60px;align-items:start}
.side{position:sticky;top:74px;display:flex;flex-direction:column;gap:3px;max-height:calc(100vh - 100px);overflow:auto}
.side .side-title{font-size:11.5px;font-weight:800;color:var(--muted);text-transform:uppercase;letter-spacing:.06em;margin:0 0 7px;padding-left:10px}
.side a{padding:7px 10px;border-radius:8px;text-decoration:none;color:var(--muted);font-size:13.5px;line-height:1.4}
.side a:hover{background:var(--surface-2);color:var(--ink)}
.side a.current{color:var(--primary);font-weight:750;background:color-mix(in srgb,var(--primary) 8%,transparent)}
.content{display:flex;flex-direction:column;gap:14px;min-width:0}

section.sect{padding:22px 0 8px;scroll-margin-top:80px}
section.sect + section.sect{border-top:1px solid var(--border);margin-top:16px;padding-top:34px}
.kicker{margin:0 0 6px;font-size:12.5px;font-weight:800;color:var(--primary)}
h2{margin:0 0 10px;font-size:26px;line-height:1.25;font-weight:850}
h3{margin:26px 0 8px;font-size:18px;font-weight:800}
.sect > p, .prose p{margin:8px 0;font-size:15px;line-height:1.78;color:var(--muted-strong)}
.sect ul, .prose ul{margin:8px 0;padding-left:20px;color:var(--muted-strong);font-size:14.5px;line-height:1.78}
.sect li+li{margin-top:4px}
.sect b, .prose b{color:var(--ink)}

/* ---------- components ---------- */
.grid{display:grid;gap:13px}
.grid.two{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid.three{grid-template-columns:repeat(3,minmax(0,1fr))}
.card{background:var(--surface);border:1px solid var(--border);border-radius:10px;padding:18px}
.card h3{margin:0 0 7px;font-size:15.5px;font-weight:800;color:var(--ink)}
.card p{margin:0;font-size:13.5px;line-height:1.66;color:var(--muted)}
.card ul{margin:8px 0 0;padding-left:17px;font-size:13.5px;line-height:1.7;color:var(--muted)}

.chapter-card{display:flex;flex-direction:column;gap:8px;background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:19px;text-decoration:none;transition:border-color .15s,transform .15s}
.chapter-card:hover{border-color:color-mix(in srgb,var(--primary) 55%,var(--border));transform:translateY(-2px)}
.chapter-card .num{display:inline-grid;place-items:center;width:30px;height:30px;border-radius:9px;background:color-mix(in srgb,var(--primary) 11%,transparent);color:var(--primary);font-weight:900;font-size:14px}
.chapter-card strong{font-size:15.5px;color:var(--ink)}
.chapter-card span{font-size:13px;line-height:1.55;color:var(--muted)}

.callout{display:flex;gap:11px;border:1px solid color-mix(in srgb,var(--primary) 26%,var(--border));background:color-mix(in srgb,var(--primary) 7%,var(--surface));border-radius:10px;padding:14px 16px;margin:14px 0;font-size:14px;line-height:1.7;color:var(--ink-2)}
.callout.warn{border-color:color-mix(in srgb,var(--amber) 38%,var(--border));background:color-mix(in srgb,var(--amber) 8%,var(--surface))}
.callout .ico{flex-shrink:0;font-size:15px;line-height:1.55}
.callout b{color:var(--ink)}
.callout p{margin:0}

.steps{list-style:none;counter-reset:step;margin:14px 0;padding:0;display:flex;flex-direction:column;gap:10px}
.steps>li{counter-increment:step;position:relative;padding:13px 15px 13px 52px;border:1px solid var(--border);border-radius:10px;background:var(--surface);font-size:14.5px;line-height:1.7;color:var(--muted-strong)}
.steps>li::before{content:counter(step);position:absolute;left:14px;top:13px;display:grid;place-items:center;width:26px;height:26px;border-radius:999px;background:var(--primary);color:#fff;font-weight:800;font-size:13px}
.steps>li b{color:var(--ink)}
.steps>li .sub{display:block;margin-top:3px;font-size:13px;color:var(--muted)}

.kbd{display:inline-flex;align-items:center;border:1px solid var(--border);border-bottom-width:2px;border-radius:6px;background:var(--surface);padding:1px 6px;font-size:12px;font-weight:800;color:var(--ink-2)}
.tag{display:inline-flex;align-items:center;gap:5px;border:1px solid var(--border);border-radius:999px;background:var(--surface-2);padding:4px 10px;color:var(--muted-strong);font-size:12px;font-weight:700}
.tag.green{color:var(--green);background:color-mix(in srgb,var(--green) 12%,transparent)}
.tag.blue{color:var(--blue);background:color-mix(in srgb,var(--blue) 12%,transparent)}
.tag.purple{color:var(--primary);background:color-mix(in srgb,var(--primary) 12%,transparent)}
.tag.amber{color:var(--amber);background:color-mix(in srgb,var(--amber) 14%,transparent)}
.tag-row{display:flex;gap:7px;flex-wrap:wrap;margin:10px 0}

.matrix{width:100%;border-collapse:collapse;border:1px solid var(--border);border-radius:10px;overflow:hidden;font-size:13.5px;margin:12px 0}
.matrix th,.matrix td{border-bottom:1px solid var(--border);padding:11px 13px;text-align:left;vertical-align:top;line-height:1.6}
.matrix th{background:var(--surface-2);color:var(--ink);font-weight:800}
.matrix td{color:var(--muted-strong)}
.matrix tr:last-child td{border-bottom:0}
.matrix td b{color:var(--ink)}
.table-scroll{overflow-x:auto}

/* ---------- screenshots ---------- */
figure.shot{margin:18px 0;display:flex;flex-direction:column;gap:9px}
figure.shot .frame{border:1px solid var(--shot-border);border-radius:12px;overflow:hidden;background:#eceef5;box-shadow:var(--shadow);cursor:zoom-in}
:root[data-theme="dark"] figure.shot .frame{background:#232733}
figure.shot img{width:100%}
figure.shot figcaption{font-size:13px;color:var(--muted);line-height:1.55;padding:0 3px}
figure.shot.narrow{max-width:560px}
figure.shot.mid{max-width:760px}
.shot-pair{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;align-items:start}

/* lightbox */
.lightbox{position:fixed;inset:0;z-index:90;display:none;align-items:center;justify-content:center;background:rgba(10,12,20,.82);padding:30px;cursor:zoom-out}
.lightbox.open{display:flex}
.lightbox img{max-width:min(1400px,96vw);max-height:92vh;width:auto;height:auto;border-radius:10px;box-shadow:0 30px 90px rgba(0,0,0,.5)}

/* ---------- page footer nav ---------- */
.page-nav{display:grid;grid-template-columns:1fr 1fr;gap:13px;margin-top:36px;padding-top:22px;border-top:1px solid var(--border)}
.page-nav a{display:flex;flex-direction:column;gap:4px;border:1px solid var(--border);border-radius:10px;background:var(--surface);padding:14px 16px;text-decoration:none}
.page-nav a:hover{border-color:color-mix(in srgb,var(--primary) 55%,var(--border))}
.page-nav .dir{font-size:12px;color:var(--muted);font-weight:700}
.page-nav .title{font-size:14.5px;color:var(--ink);font-weight:800}
.page-nav a.next{text-align:right;grid-column:2}
.page-nav a.prev{grid-column:1}

footer.site{border-top:1px solid var(--border);background:var(--surface-2);padding:30px 0;color:var(--muted);font-size:13px}
footer.site .wrap{display:flex;align-items:center;justify-content:space-between;gap:16px;flex-wrap:wrap}
footer.site a{text-decoration:none}
footer.site a:hover{color:var(--ink)}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:42px;border-radius:9px;padding:0 17px;text-decoration:none;font-weight:750;font-size:14px;border:1px solid var(--border);background:var(--surface);color:var(--ink-2)}
.btn.primary{background:var(--primary);border-color:var(--primary);color:#fff}
.hero-actions{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-top:22px}

/* ---------- responsive ---------- */
@media (max-width:1020px){
  .layout{grid-template-columns:1fr;gap:10px}
  .side{position:static;max-height:none;flex-direction:row;flex-wrap:wrap;gap:6px;padding:12px;border:1px solid var(--border);border-radius:10px;background:var(--surface)}
  .side .side-title{width:100%;padding-left:2px}
  .side a{border:1px solid var(--border);background:var(--surface-2)}
  h1{font-size:30px}
  .grid.three{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (max-width:640px){
  .wrap{padding:0 16px}
  .nav{padding:10px 14px}
  .nav-right .home-link{display:none}
  h1{font-size:26px}
  .lead{font-size:15px}
  .grid.two,.grid.three,.shot-pair{grid-template-columns:1fr}
  .hero{padding-top:32px}
  .page-nav{grid-template-columns:1fr}
  .page-nav a.next{grid-column:auto;text-align:left}
}