:root{
  --bg:#0b1020;
  --bg-soft:#111832;
  --card:#121b37;
  --card-2:#172246;
  --text:#eef4ff;
  --muted:#a9b7d1;
  --line:#26345f;
  --primary:#6f86ff;
  --primary-2:#8b5cf6;
  --accent:#22d3ee;
  --success:#34d399;
  --shadow:0 24px 70px rgba(0,0,0,.28);
  --radius:24px;
  --max:1180px;
}
[data-theme="light"]{
  --bg:#f3f7ff;
  --bg-soft:#ffffff;
  --card:#ffffff;
  --card-2:#f8fbff;
  --text:#13203d;
  --muted:#5d6d8d;
  --line:#d8e2f3;
  --primary:#3f5cff;
  --primary-2:#7c3aed;
  --accent:#0891b2;
  --success:#059669;
  --shadow:0 24px 70px rgba(31,57,111,.12);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
/* Suppress ALL transitions during initial page load to prevent flash */
html.loading *{transition-duration:0s !important;animation-duration:0s !important}
/* Theme toggle icon: CSS-driven, no JS DOM update needed */
.theme-toggle .fa-moon{display:none}
[data-theme="light"] .theme-toggle .fa-sun{display:none}
[data-theme="light"] .theme-toggle .fa-moon{display:block}
body{
  margin:0;
  font-family:Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  color:var(--text);
  background:
    radial-gradient(circle at 15% 15%, rgba(111,134,255,.18), transparent 28%),
    radial-gradient(circle at 85% 18%, rgba(34,211,238,.12), transparent 24%),
    linear-gradient(180deg,var(--bg) 0%, rgba(18,32,74,.1) 50%, var(--bg) 100%);
  line-height:1.65;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.container{width:min(var(--max), calc(100% - 32px));margin:0 auto}
.scroll-progress{position:fixed;top:0;left:0;height:3px;background:linear-gradient(90deg,var(--accent),var(--primary));z-index:4000;width:0%}
.custom-navbar{
  position:sticky;top:0;z-index:3000;
  backdrop-filter: blur(16px);
  background:color-mix(in srgb, var(--bg) 86%, transparent);
  border-bottom:1px solid color-mix(in srgb, var(--text) 8%, transparent);
}
.nav-wrap{display:flex;align-items:center;justify-content:space-between;padding:16px 0;gap:20px}
.nav-brand{font-weight:800;font-size:1.05rem;letter-spacing:.02em}
.nav-links{display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.nav-link{
  color:var(--muted);padding:10px 14px;border-radius:999px;
  transition:.22s ease;
}
.nav-link:hover,.nav-link.active{background:color-mix(in srgb, var(--primary) 14%, transparent);color:var(--text)}
.theme-toggle{
  width:42px;height:42px;border-radius:999px;border:1px solid var(--line);background:var(--card);color:var(--text);
  cursor:pointer;display:grid;place-items:center;transition:.2s ease
}
.theme-toggle:hover{opacity:.8}
.lang-toggle{
  height:42px;padding:0 16px;min-width:52px;
  border-radius:999px;border:1px solid var(--line);background:var(--card);color:var(--text);
  cursor:pointer;display:grid;place-items:center;transition:.2s ease;
  font-size:.8rem;font-weight:800;letter-spacing:.08em
}
.lang-toggle:hover{opacity:.8}
.page{padding:40px 0 88px}
.hero{padding:52px 0 20px}
.hero-grid{display:grid;grid-template-columns:1.08fr .92fr;gap:28px;align-items:center}
.hero-badge,.section-badge{
  display:inline-flex;align-items:center;gap:10px;
  border:1px solid color-mix(in srgb, var(--text) 8%, transparent);
  background:color-mix(in srgb, var(--card) 88%, transparent);
  color:var(--text);padding:10px 14px;border-radius:999px;font-size:.92rem;font-weight:700
}
.hero h1,.page-title{
  font-size:clamp(2.5rem, 5vw, 4.6rem);
  line-height:1.02;letter-spacing:-.04em;margin:18px 0 16px;font-weight:900
}
.gradient-text{
  background:linear-gradient(135deg, color-mix(in srgb, var(--text) 92%, white 8%) 0%, color-mix(in srgb, var(--primary) 70%, white 30%) 35%, color-mix(in srgb, var(--accent) 70%, white 30%) 100%);
  -webkit-background-clip:text;background-clip:text;color:transparent
}
.lead{color:var(--muted);font-size:1.1rem;max-width:760px}
.kpi-row{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin:28px 0}
.kpi{
  background:linear-gradient(180deg,color-mix(in srgb, var(--card) 92%, white 8%),color-mix(in srgb, var(--card) 98%, black 2%));
  border:1px solid color-mix(in srgb, var(--text) 8%, transparent);
  border-radius:20px;padding:18px 18px 16px;box-shadow:var(--shadow)
}
.kpi-number{font-size:1.7rem;font-weight:900;letter-spacing:-.03em}
.kpi-label{font-size:.9rem;color:var(--muted);margin-top:4px}
.cta-row{display:flex;gap:12px;flex-wrap:wrap;margin-top:16px}
.btn-main,.btn-sub,.btn-chip{
  display:inline-flex;align-items:center;gap:10px;
  border-radius:16px;padding:13px 18px;font-weight:800;transition:.2s ease
}
.btn-main{background:linear-gradient(135deg,var(--primary),var(--primary-2));color:#fff;border:none}
.btn-sub{border:1px solid var(--line);background:color-mix(in srgb, var(--card) 92%, transparent);color:var(--text)}
.btn-main:hover,.btn-sub:hover,.btn-chip:hover{opacity:.88}
.hero-visual{
  position:relative;background:linear-gradient(180deg,color-mix(in srgb, var(--card) 96%, white 4%),color-mix(in srgb, var(--card) 99%, black 1%));
  border:1px solid color-mix(in srgb, var(--text) 8%, transparent);border-radius:32px;padding:18px;box-shadow:var(--shadow)
}
.visual-card{overflow:hidden;border-radius:24px;background:var(--bg);border:1px solid color-mix(in srgb, var(--text) 8%, transparent)}
.visual-caption{display:flex;justify-content:space-between;gap:12px;padding:14px 6px 0;color:var(--muted);font-size:.92rem}
.section{margin-top:86px}
.section-head{display:flex;justify-content:space-between;align-items:end;gap:18px;margin-bottom:22px}
.section-title{font-size:clamp(1.7rem,2.8vw,2.6rem);line-height:1.1;letter-spacing:-.03em;margin:10px 0 0;font-weight:850}
.section-copy{color:var(--muted);max-width:760px}
.card-grid{display:grid;gap:20px}
.two{grid-template-columns:repeat(2,1fr)}
.three{grid-template-columns:repeat(3,1fr)}
.content-card,.project-card,.resource-card,.timeline-card,.quote-card,.feature-card{
  background:linear-gradient(180deg,color-mix(in srgb, var(--card) 96%, white 4%),color-mix(in srgb, var(--card) 99%, black 1%));
  border:1px solid color-mix(in srgb, var(--text) 8%, transparent);
  border-radius:28px;padding:24px;box-shadow:var(--shadow)
}
.content-card h3,.project-card h3,.resource-card h3,.timeline-card h3,.feature-card h3{margin:0 0 10px;font-size:1.35rem}
.card-meta{display:inline-block;color:color-mix(in srgb, var(--primary) 35%, white 65%);background:color-mix(in srgb, var(--primary) 14%, transparent);border:1px solid color-mix(in srgb, var(--primary) 22%, transparent);padding:6px 10px;border-radius:999px;font-size:.8rem;margin-bottom:12px}
.text-muted{color:var(--muted)}
.bullet-list{padding-left:18px;margin:12px 0 0}
.bullet-list li{margin:7px 0;color:var(--muted)}
.system-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-top:18px}
.system-box{
  border:1px solid color-mix(in srgb, var(--text) 8%, transparent);background:color-mix(in srgb, var(--card-2) 94%, transparent);
  border-radius:22px;padding:18px
}
.system-box h4{margin:0 0 8px;font-size:1rem}
.system-box p{margin:0;color:var(--muted);font-size:.95rem}
.highlight{color:var(--text);font-weight:800}
.image-grid{display:grid;grid-template-columns:1.2fr .8fr;gap:16px;margin-top:18px}
.image-stack{display:grid;gap:16px}
.image-card{
  background:color-mix(in srgb, var(--card-2) 94%, transparent);border:1px solid color-mix(in srgb, var(--text) 8%, transparent);
  border-radius:22px;padding:14px
}
.image-card img{border-radius:16px}
.image-title{margin:0 0 12px;font-size:.98rem;color:var(--text);font-weight:800}
.timeline{display:grid;gap:18px}
.timeline-date{color:var(--accent);font-size:.92rem;font-weight:800;margin-bottom:8px}
.downloads{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}
.download-card{
  background:linear-gradient(180deg,color-mix(in srgb, var(--card) 96%, white 4%),color-mix(in srgb, var(--card) 99%, black 1%));
  border:1px solid color-mix(in srgb, var(--text) 8%, transparent);border-radius:24px;padding:22px
}
.download-card p{color:var(--muted)}
.footer{padding:40px 0 60px;color:var(--muted)}
.inline-note{
  margin-top:18px;padding:16px 18px;border-radius:18px;
  border:1px solid color-mix(in srgb, var(--accent) 24%, transparent);background:color-mix(in srgb, var(--accent) 7%, transparent);color:var(--text)
}
.quote-card{font-size:1.08rem}
.quote-card strong{display:block;margin-bottom:6px}

.feature-card{
  padding:0;overflow:hidden;transition:.2s ease
}
.feature-card:hover{box-shadow:0 12px 40px rgba(111,134,255,.22)}
.feature-thumb{
  aspect-ratio:16/10;
  overflow:hidden;
  background:var(--bg-soft);
  border-bottom:1px solid color-mix(in srgb, var(--text) 8%, transparent);
}
.feature-thumb img{width:100%;height:100%;object-fit:cover}
.feature-body{padding:20px 20px 22px}
.feature-body p{color:var(--muted);margin:0 0 14px}
.mini-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}
.note-block{
  border-left:4px solid var(--accent);
  padding:6px 0 6px 16px;color:var(--muted)
}

/* Launcher pulse ring */
.chatbot-launcher-wrap{
  position:fixed;right:24px;bottom:24px;z-index:5000
}
.launcher-ring{
  position:absolute;inset:-6px;
  border-radius:50%;
  border:2px solid rgba(111,134,255,.5);
  animation:launcherRing 2s ease-out infinite;
  pointer-events:none
}
.launcher-ring-2{
  position:absolute;inset:-6px;
  border-radius:50%;
  border:2px solid rgba(111,134,255,.3);
  animation:launcherRing 2s ease-out .7s infinite;
  pointer-events:none
}
@keyframes launcherRing{
  from{transform:scale(1);opacity:.8}
  to{transform:scale(1.55);opacity:0}
}

/* Chatbot */
.chatbot-launcher{
  position:relative;width:64px;height:64px;border:none;border-radius:999px;
  background:linear-gradient(135deg,var(--primary),var(--primary-2));color:#fff;
  box-shadow:0 20px 44px rgba(36,88,255,.30);cursor:pointer;
  display:grid;place-items:center
}
.chatbot-panel{
  position:fixed;right:24px;bottom:98px;z-index:5000;width:min(390px, calc(100vw - 24px));max-height:min(72vh,760px);
  display:flex;flex-direction:column;overflow:hidden;border-radius:24px;background:var(--card);border:1px solid var(--line);box-shadow:var(--shadow)
}
.chatbot-panel.hidden{display:none}
.chatbot-header{
  background:linear-gradient(135deg,var(--primary),var(--primary-2));
  padding:16px 16px 14px;color:#fff;display:flex;justify-content:space-between;gap:10px
}
.chatbot-header h3{margin:0;font-size:1rem}
.chatbot-header p{margin:6px 0 0;font-size:.84rem;opacity:.92}
.chatbot-close{
  width:34px;height:34px;border:none;border-radius:999px;background:rgba(255,255,255,.16);color:#fff;cursor:pointer
}
.chatbot-body{flex:1;padding:14px;background:var(--bg-soft);overflow-y:auto;display:flex;flex-direction:column;gap:0}
.chatbot-messages{display:flex;flex-direction:column;gap:12px}
.chat-msg{display:flex;gap:8px;align-items:flex-start}
.chat-msg.user{justify-content:flex-end}
.chat-avatar{
  width:34px;height:34px;border-radius:999px;display:flex;align-items:center;justify-content:center;flex:0 0 auto
}
.chat-avatar.bot{background:color-mix(in srgb, var(--primary) 16%, transparent);color:var(--text)}
.chat-avatar.user{background:color-mix(in srgb, var(--accent) 16%, transparent);color:var(--text);order:2}
.chat-bubble{
  max-width:84%;padding:12px 14px;border-radius:18px;border:1px solid var(--line);background:var(--card-2)
}
.chat-msg.user .chat-bubble{background:linear-gradient(135deg,var(--primary),var(--primary-2));border:none;color:#fff}
.chatbot-suggestions{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}
.chatbot-chip{
  border:1px solid var(--line);background:var(--card);color:var(--muted);padding:8px 12px;border-radius:999px;cursor:pointer
}
.chatbot-footer{padding:12px;border-top:1px solid var(--line);background:var(--card)}
.chatbot-form{display:flex;gap:8px}
.chatbot-input{
  flex:1;min-width:0;border:1px solid var(--line);border-radius:14px;padding:12px 14px;background:var(--bg-soft);color:var(--text)
}
.chatbot-send{
  width:46px;height:46px;border:none;border-radius:14px;background:linear-gradient(135deg,var(--primary),var(--primary-2));color:#fff;cursor:pointer
}
.chatbot-note{margin-top:8px;font-size:.76rem;color:var(--muted)}

@media (max-width: 980px){
  .hero-grid,.two,.three,.downloads,.image-grid,.system-grid,.mini-grid{grid-template-columns:1fr}
}
@media (max-width: 760px){
  .custom-navbar { position: static; }
  .nav-wrap{align-items:flex-start;flex-direction:column}
  .nav-links{gap:8px}
  .kpi-row{grid-template-columns:repeat(2,1fr)}
  .page{padding-bottom:72px}
}
@media (max-width: 560px){
  .kpi-row{grid-template-columns:1fr}
  .chatbot-panel{left:12px;right:12px;width:auto;bottom:88px}
  .chatbot-launcher-wrap{right:16px;bottom:16px}
}

/* ===== Animations ===== */
/* Default: always visible (JS-independent) */
.fade-up{
  transition:opacity .8s cubic-bezier(.22,1,.36,1), transform .8s cubic-bezier(.22,1,.36,1);
}
.fade-up.show{ opacity:1; transform:translateY(0); }

/* Only hide when JS animation is active */
.js-anim .fade-up:not(.show){
  opacity:0;
  transform:translateY(40px);
}

.scale-in{
  transition:opacity .7s ease, transform .7s ease;
}
.scale-in.show{ opacity:1; transform:scale(1); }

.js-anim .scale-in:not(.show){
  opacity:0;
  transform:scale(.9);
}

.hover-glow:hover{
  box-shadow:0 20px 60px rgba(111,134,255,.35), var(--shadow);
}


/* ===== Splash Loader ===== */
.splash-loader{
  position:fixed; inset:0; z-index:9999;
  display:flex; align-items:center; justify-content:center;
  background:radial-gradient(circle at 50% 35%, rgba(111,134,255,.20), transparent 30%), var(--bg);
  transition:opacity .8s ease, visibility .8s ease;
}
.splash-loader.hidden{
  opacity:0; visibility:hidden; pointer-events:none;
}
.splash-card{
  width:min(480px, calc(100vw - 32px));
  padding:34px 30px 28px;
  border-radius:28px;
  background:linear-gradient(180deg, color-mix(in srgb, var(--card) 96%, white 4%), color-mix(in srgb, var(--card) 99%, black 1%));
  border:1px solid color-mix(in srgb, var(--text) 8%, transparent);
  box-shadow:var(--shadow);
  text-align:center;
}
.splash-logo{
  width:78px; height:78px; border-radius:24px; margin:0 auto 18px;
  display:grid; place-items:center;
  background:linear-gradient(135deg,var(--primary),var(--primary-2));
  color:#fff; font-size:2rem;
  animation:splashPulse 1.6s ease-in-out infinite;
}
.splash-title{
  margin:0; font-size:2rem; letter-spacing:-.03em; font-weight:900;
}
.splash-copy{
  color:var(--muted); margin:10px 0 18px;
}
.splash-bar{
  height:10px; border-radius:999px; overflow:hidden;
  background:color-mix(in srgb, var(--card-2) 92%, transparent);
  border:1px solid color-mix(in srgb, var(--text) 8%, transparent);
}
.splash-bar > span{
  display:block; height:100%; width:0%;
  background:linear-gradient(135deg,var(--accent),var(--primary));
  animation:splashLoad 2.2s cubic-bezier(.22,1,.36,1) forwards;
}
.splash-meta{
  margin-top:12px; font-size:.84rem; color:var(--muted);
}
@keyframes splashLoad{ from{width:0%} to{width:100%} }
@keyframes splashPulse{
  0%,100%{ transform:scale(1); box-shadow:0 0 0 rgba(111,134,255,0) }
  50%{ transform:scale(1.05); box-shadow:0 0 28px rgba(111,134,255,.32) }
}

/* ===== Video section ===== */
.demo-shell{
  display:grid; grid-template-columns:1.1fr .9fr; gap:20px;
  align-items:center;
}
.demo-box{
  border-radius:24px; overflow:hidden;
  border:1px solid color-mix(in srgb, var(--text) 8%, transparent);
  background:linear-gradient(180deg,color-mix(in srgb, var(--card) 96%, white 4%),color-mix(in srgb, var(--card) 99%, black 1%));
  box-shadow:var(--shadow);
}
.demo-video{
  width:100%;
  aspect-ratio:16/9;
  display:block;
  background:color-mix(in srgb, var(--bg-soft) 96%, black 4%);
}
@media (max-width: 980px){
  .demo-shell{ grid-template-columns:1fr; }
}

/* ===== Skills Section ===== */
.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}
.skill-tag {
  display: inline-block;
  padding: 8px 14px;
  background: linear-gradient(135deg, rgba(111,134,255,.12), rgba(34,211,238,.08));
  border: 1px solid rgba(111,134,255,.2);
  border-radius: 999px;
  font-size: 0.9rem;
  color: var(--text);
  transition: all .2s ease;
}
.skill-tag:hover {
  background: linear-gradient(135deg, rgba(111,134,255,.18), rgba(34,211,238,.12));
  border-color: rgba(111,134,255,.35);
}

/* ===== Skill Groups ===== */
.skill-groups { display: flex; flex-direction: column; gap: 28px }
.skill-group-label {
  font-size: .82rem; font-weight: 700; color: var(--primary);
  margin-bottom: 10px; letter-spacing: .07em; text-transform: uppercase
}

/* ===== Language Toggle — CSS-driven ===== */
.t-ko { display: none }
[data-lang="ko"] .t-en { display: none }
[data-lang="ko"] .t-ko { display: inline }

/* Nav links: overlay both texts so width never changes on lang switch */
.nav-link { display: inline-grid; place-items: center; text-align: center }
.nav-link .t-en,
.nav-link .t-ko { grid-area: 1/1 }

/* t-ko is invisible by default but still occupies space in nav */
.nav-link .t-ko {
  display: inline;        /* override global display:none */
  visibility: hidden;
  pointer-events: none
}
/* In KO mode: keep t-en in DOM (it still reserves width) but hide it */
[data-lang="ko"] .nav-link .t-en {
  display: inline;        /* override global display:none */
  visibility: hidden;
  pointer-events: none
}
[data-lang="ko"] .nav-link .t-ko {
  visibility: visible;
  pointer-events: auto
}