/* ═══════════════════════════════════════════════════════════════════
   FURYUS — "Instrument Black" design system
   회사 사이트 공유 스타일 (index.html + products/ai-core.html)
   원칙: OLED 순흑 · 모노크롬 + fathom 블루 1색 · 시스템 SF · 웹폰트 0
        애니메이션은 transform/opacity만 (60fps) · 다크 전용
   제품 페이지(divecore)는 자체 월드를 유지 — 이 파일을 쓰지 않음
   ═══════════════════════════════════════════════════════════════════ */

:root {
  --void:    #000000;            /* 배경 — OLED 순흑 */
  --elev:    #0a0a0c;            /* 카드 표면 */
  --elev-2:  #101014;            /* 표면 hover */
  --signal:  #f5f5f7;            /* 헤드라인 (Apple off-white) */
  --t2:      #a6a6ad;            /* 본문 */
  --t3:      #6e6e73;            /* 라벨·캡션 */
  --fathom:  #52a8ff;            /* 유일한 액센트 — 라벨/포커스/미세 글로우에만 */
  --line:    rgba(255,255,255,.08);   /* 헤어라인 = 순흑에서의 엘리베이션 */
  --line-2:  rgba(255,255,255,.17);
  --r:       16px;
  --r-lg:    24px;
  --max:     1120px;
  --nav-h:   60px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
          "Apple SD Gothic Neo", system-ui, "Segoe UI", Roboto, sans-serif;
  --ease:  cubic-bezier(.22, 1, .36, 1);
}

/* ── Base ─────────────────────────────────────────────── */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 24px); -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font);
  background: var(--void);
  color: var(--signal);
  line-height: 1.5;
  letter-spacing: -0.01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  word-break: keep-all;
  overflow-wrap: break-word;
  overflow-x: hidden;
}
/* no-flash i18n 게이팅 (JS 없으면 그대로 보임) */
.js body { opacity: 0; transition: opacity .25s ease; }
.js.lang-ready body { opacity: 1; }

a { color: inherit; text-decoration: none; }
img, svg, video { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
::selection { background: rgba(82,168,255,.25); color: #fff; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--fathom); outline-offset: 3px; border-radius: 6px; }

.skip-link { position: absolute; left: -9999px; top: 12px; z-index: 300; background: var(--signal); color: #000;
  padding: 10px 16px; border-radius: 999px; font-size: 13px; font-weight: 600; }
.skip-link:focus { left: 12px; }

.container { max-width: var(--max); margin: 0 auto; padding: 0 24px; width: 100%; }
.section { padding: clamp(96px, 12vw, 152px) 0; position: relative; }

/* Horizon Line — 시그니처: 페이지를 관통하는 1px 기준선 */
.horizon { border: 0; height: 1px; background: var(--line); }

/* ── Typography ───────────────────────────────────────── */
.label {
  font-size: 12px; font-weight: 600; letter-spacing: .16em; text-transform: uppercase;
  color: var(--t3);
}
.label--accent { color: var(--fathom); }
.f-display {
  font-size: clamp(48px, 8vw, 92px); font-weight: 700;
  letter-spacing: -0.035em; line-height: 1.04; color: var(--signal);
}
.f-display .dim { display: block; color: var(--t3); }
.f-h2 { font-size: clamp(34px, 4.6vw, 52px); font-weight: 700; letter-spacing: -0.03em; line-height: 1.08; }
.f-lead { font-size: clamp(16px, 1.8vw, 19px); color: var(--t2); line-height: 1.6; max-width: 580px; }
.center { text-align: center; }
.center .f-lead { margin-left: auto; margin-right: auto; }
.sec-head { margin-bottom: clamp(40px, 6vw, 72px); }
.sec-head .label { display: block; margin-bottom: 16px; }

/* ── Nav ──────────────────────────────────────────────── */
.f-nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100; height: var(--nav-h);
  transition: background .3s ease, border-color .3s ease, backdrop-filter .3s ease;
  border-bottom: 1px solid transparent;
}
.f-nav.is-scrolled {
  background: rgba(0,0,0,.72);
  -webkit-backdrop-filter: saturate(140%) blur(20px); backdrop-filter: saturate(140%) blur(20px);
  border-bottom-color: var(--line);
}
.f-nav-inner { max-width: var(--max); height: 100%; margin: 0 auto; padding: 0 24px;
  display: flex; align-items: center; gap: 28px; }
.f-brand { display: inline-flex; align-items: center; gap: 10px; color: var(--signal); }
.f-brand:hover { color: #fff; }
/* FURYUS 로고 v3 — 이탤릭 2-스트로크 F 엠블럼 + 얇은 와이드트래킹 워드마크 */
.logo-em { height: 19px; width: auto; display: block; fill: currentColor; }
.logo-word { font-size: 13px; font-weight: 300; letter-spacing: .34em; line-height: 1; color: inherit; transform: translateY(.5px); }
.f-footer .logo-em { height: 20px; }
.f-footer .logo-word { font-size: 13.5px; }
.f-links { display: flex; align-items: center; gap: 28px; margin-left: auto; list-style: none; }
.f-links a, .dd-btn { font-size: 14px; color: var(--t2); transition: color .2s; padding: 6px 0; }
.f-links a:hover, .dd-btn:hover { color: var(--signal); }

/* Products 드롭다운 */
.dd { position: relative; }
.dd-btn { display: inline-flex; align-items: center; gap: 6px; }
.dd-btn .chev { width: 8px; height: 8px; border-right: 1.5px solid currentColor; border-bottom: 1.5px solid currentColor;
  transform: rotate(45deg) translateY(-2px); transition: transform .2s; }
.dd.open .dd-btn { color: var(--signal); }
.dd.open .dd-btn .chev { transform: rotate(-135deg) translateY(-2px); }
.dd-panel {
  position: absolute; top: calc(100% + 12px); left: 50%; transform: translate(-50%, 6px);
  min-width: 264px; padding: 8px; border-radius: var(--r);
  background: rgba(12,12,15,.92);
  -webkit-backdrop-filter: blur(24px) saturate(140%); backdrop-filter: blur(24px) saturate(140%);
  border: 1px solid var(--line-2);
  box-shadow: 0 24px 64px rgba(0,0,0,.6);
  opacity: 0; visibility: hidden; pointer-events: none;
  transition: opacity .22s var(--ease), transform .22s var(--ease), visibility 0s .22s;
}
.dd.open .dd-panel { opacity: 1; visibility: visible; pointer-events: auto;
  transform: translate(-50%, 0); transition-delay: 0s; }
.dd-item { display: flex; align-items: baseline; justify-content: space-between; gap: 14px;
  padding: 12px 14px; border-radius: 10px; transition: background .18s; }
.dd-item:hover { background: rgba(255,255,255,.05); }
.dd-item b { display: block; font-size: 14px; font-weight: 600; color: var(--signal); letter-spacing: .02em; }
.dd-item span { display: block; font-size: 12px; color: var(--t3); margin-top: 2px; }
.soon-pill { flex-shrink: 0; font-size: 9.5px; font-weight: 700; letter-spacing: .12em; text-transform: uppercase;
  color: var(--t3); border: 1px solid var(--line-2); border-radius: 999px; padding: 3px 8px; white-space: nowrap; }

/* 언어 토글 (모노크롬) */
.f-lang { display: inline-flex; border: 1px solid var(--line); border-radius: 999px; padding: 2px; }
.f-lang button { font-size: 11px; font-weight: 600; color: var(--t3); padding: 4px 11px; border-radius: 999px; transition: all .18s; }
.f-lang button.active { background: var(--signal); color: #000; }

@media (max-width: 860px) { .hide-m { display: none; } .f-nav-inner { gap: 18px; } }

/* ── Buttons ──────────────────────────────────────────── */
.btn-solid {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  background: var(--signal); color: #000; font-size: 15px; font-weight: 600;
  padding: 14px 28px; border-radius: 999px;
  transition: transform .2s var(--ease), background .2s;
}
.btn-solid:hover { background: #fff; transform: translateY(-1px); }
.btn-link { display: inline-flex; align-items: center; gap: 6px; font-size: 15px; font-weight: 500;
  color: var(--t2); transition: color .2s; }
.btn-link:hover { color: var(--signal); }

/* ── Hero ─────────────────────────────────────────────── */
.f-hero { position: relative; padding: calc(var(--nav-h) + clamp(72px, 12vh, 128px)) 0 clamp(56px, 8vh, 96px);
  text-align: center; overflow: hidden; }
.f-hero::before { /* 상단 앰비언트 — 아주 은은한 단일 광원 */
  content: ""; position: absolute; inset: -20% -10% auto; height: 70%;
  background: radial-gradient(52% 62% at 50% 0%, rgba(82,168,255,.055), transparent 70%);
  pointer-events: none;
}
.f-hero .f-lead { margin: 28px auto 0; }
.f-hero-ctas { display: flex; gap: 22px; justify-content: center; align-items: center; margin-top: 40px; flex-wrap: wrap; }

.hero-device { position: relative; width: min(430px, 84vw); margin: clamp(40px, 7vh, 80px) auto 0; }
.hero-device .dv {
  width: 100%; aspect-ratio: 800 / 940; object-fit: cover; transform: scale(1.06);
  -webkit-mask-image: radial-gradient(62% 62% at 50% 48%, #000 44%, transparent 78%);
  mask-image: radial-gradient(62% 62% at 50% 48%, #000 44%, transparent 78%);
}
.float { animation: f-float 6.5s ease-in-out infinite; will-change: transform; }
@keyframes f-float { 0%,100% { transform: translateY(0) } 50% { transform: translateY(-10px) } }

/* 스크롤 큐 — Horizon Line의 시작점 (수직 1px이 숨쉬듯) */
.scroll-cue { position: relative; width: 1px; height: 52px; margin: clamp(36px, 6vh, 64px) auto 0;
  background: var(--line-2); overflow: hidden; transition: opacity .5s; }
.scroll-cue::after { content: ""; position: absolute; left: 0; top: -40%; width: 100%; height: 40%;
  background: var(--signal); animation: cue-drop 2.2s var(--ease) infinite; }
@keyframes cue-drop { 0% { top: -40% } 70%, 100% { top: 110% } }
.scroll-cue.gone { opacity: 0; }

/* ── Product cards ────────────────────────────────────── */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
@media (max-width: 900px) { .grid-2, .grid-3 { grid-template-columns: 1fr; } }

.p-card { position: relative; display: flex; flex-direction: column; min-height: 460px;
  background: var(--elev); border: 1px solid var(--line); border-radius: var(--r-lg);
  padding: 36px 34px 0; overflow: hidden;
  transition: transform .35s var(--ease), border-color .35s, background .35s; }
.p-card:hover { transform: translateY(-4px); border-color: var(--line-2); background: var(--elev-2); }
.p-card .p-name { font-size: 13px; font-weight: 700; letter-spacing: .2em; color: var(--signal); }
.p-card .p-tag { font-size: clamp(21px, 2.4vw, 26px); font-weight: 700; letter-spacing: -0.02em; margin-top: 14px; line-height: 1.15; }
.p-card .p-desc { font-size: 15px; color: var(--t2); line-height: 1.6; margin-top: 12px; max-width: 44ch; }
.p-card .p-link { margin-top: 18px; font-size: 14px; font-weight: 600; color: var(--t2); transition: color .2s; }
.p-card:hover .p-link { color: var(--signal); }
.p-media { margin-top: auto; display: flex; justify-content: center; }
.p-media img { width: min(320px, 78%); height: auto;  /* height:auto 필수 — HTML height 속성이 남아 세로로 늘어나는 버그 방지 */
  /* 포스터 자체의 네이비 배경을 카드 표면으로 페더링 — 사각 경계 제거 */
  -webkit-mask-image: radial-gradient(70% 64% at 50% 46%, #000 44%, transparent 80%);
  mask-image: radial-gradient(70% 64% at 50% 46%, #000 44%, transparent 80%); }

/* DiveCore 카드 — hover 시 제품 월드(오션)가 스며듦 */
.p-card--dive::after { content: ""; position: absolute; inset: 0; pointer-events: none; opacity: 0;
  background: radial-gradient(90% 60% at 50% 100%, rgba(42,212,236,.09), transparent 70%);
  transition: opacity .4s var(--ease); }
.p-card--dive:hover::after { opacity: 1; }

/* AI CORE 카드 — 실물이 없으므로 고스트 워드마크 (정직한 비주얼) */
.p-card--soon .p-name, .p-card--soon .p-tag { color: var(--t2); }
.ghost-mark { font-size: clamp(56px, 7vw, 84px); font-weight: 800; letter-spacing: .04em; line-height: 1;
  color: transparent; -webkit-text-stroke: 1px rgba(255,255,255,.13); padding-bottom: 40px; user-select: none; }
.p-card--soon:hover .ghost-mark { -webkit-text-stroke-color: rgba(82,168,255,.28); transition: -webkit-text-stroke-color .4s; }

/* ── Why 카드 (아이콘 없음 — 타이포 중심) ─────────────── */
.f-card { background: var(--elev); border: 1px solid var(--line); border-radius: var(--r);
  padding: 30px 28px; transition: transform .3s var(--ease), border-color .3s; }
.f-card:hover { transform: translateY(-3px); border-color: var(--line-2); }
.f-card h3 { font-size: 18px; font-weight: 600; letter-spacing: -0.01em; }
.f-card p { font-size: 14.5px; color: var(--t2); line-height: 1.6; margin-top: 10px; }
.f-card .k { display: block; font-size: 11px; font-weight: 600; letter-spacing: .14em;
  text-transform: uppercase; color: var(--t3); margin-bottom: 14px; }

/* ── Experience (몰입 섹션) ───────────────────────────── */
.exp { text-align: center; overflow: hidden; }
.exp .f-h2 { font-size: clamp(40px, 6.6vw, 76px); }
.exp .f-lead { margin: 22px auto 0; }
.exp-device { width: min(380px, 74vw); margin: clamp(40px, 6vw, 64px) auto 0; will-change: transform; }
.exp-device img {
  height: auto;  /* HTML height 속성 잔존으로 인한 세로 늘어남 방지 */
  -webkit-mask-image: radial-gradient(66% 62% at 50% 46%, #000 46%, transparent 80%);
  mask-image: radial-gradient(66% 62% at 50% 46%, #000 46%, transparent 80%);
}

/* ── Roadmap 타임라인 (Horizon Line이 레일이 됨) ──────── */
.tl { position: relative; max-width: 720px; }
.tl::before { content: ""; position: absolute; left: 3px; top: 8px; bottom: 8px; width: 1px; background: var(--line); }
.tl-item { position: relative; padding: 0 0 44px 40px; }
.tl-item:last-child { padding-bottom: 0; }
.tl-item::before { content: ""; position: absolute; left: 0; top: 7px; width: 7px; height: 7px; border-radius: 50%;
  background: var(--void); border: 1px solid var(--t3); }
.tl-item.now::before { background: var(--fathom); border-color: var(--fathom); box-shadow: 0 0 12px rgba(82,168,255,.5); }
.tl-when { font-size: 12px; font-weight: 600; letter-spacing: .14em; text-transform: uppercase; color: var(--t3); }
.tl-item.now .tl-when { color: var(--fathom); }
.tl-what { font-size: clamp(18px, 2vw, 21px); font-weight: 600; letter-spacing: -0.01em; margin-top: 8px; }
.tl-sub { font-size: 14.5px; color: var(--t2); margin-top: 6px; line-height: 1.55; }

/* ── Engineering Principles (매니페스토 리스트) ───────── */
.plist { border-top: 1px solid var(--line); }
.p-row { display: grid; grid-template-columns: minmax(220px, 340px) 1fr; gap: 16px 40px;
  padding: 26px 0; border-bottom: 1px solid var(--line); }
.p-row h3 { font-size: 18px; font-weight: 600; letter-spacing: -0.01em; }
.p-row p { font-size: 15px; color: var(--t2); line-height: 1.6; }
@media (max-width: 720px) { .p-row { grid-template-columns: 1fr; gap: 6px; } }

/* ── Footer ───────────────────────────────────────────── */
.f-footer { border-top: 1px solid var(--line); padding: 56px 0 44px; }
.f-foot-top { display: flex; justify-content: space-between; align-items: flex-start; gap: 32px; flex-wrap: wrap; }
.f-foot-tag { font-size: 14px; color: var(--t3); margin-top: 12px; max-width: 320px; line-height: 1.6; }
.f-foot-links { display: flex; gap: 24px; flex-wrap: wrap; list-style: none; }
.f-foot-links a { font-size: 13.5px; color: var(--t2); transition: color .2s; }
.f-foot-links a:hover { color: var(--signal); }
.f-foot-bot { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap;
  margin-top: 44px; padding-top: 24px; border-top: 1px solid var(--line);
  font-size: 12.5px; color: var(--t3); }

/* ── Mouse light (데스크톱 fine-pointer 전용, transform만) ── */
.m-orb { position: fixed; left: 0; top: 0; width: 640px; height: 640px; margin: -320px 0 0 -320px;
  border-radius: 50%; pointer-events: none; z-index: 1; opacity: 0; transition: opacity .6s ease;
  background: radial-gradient(circle, rgba(82,168,255,.06), transparent 68%);
  will-change: transform; }
.m-orb.on { opacity: 1; }

/* ── Reveal (IO 게이트) ───────────────────────────────── */
.js [data-reveal] { opacity: 0; transform: translateY(24px); filter: blur(6px);
  transition: opacity .7s var(--ease), transform .7s var(--ease), filter .7s var(--ease); }
.js [data-reveal].in { opacity: 1; transform: none; filter: none; }

/* ── Reduced motion — 전부 정지 ───────────────────────── */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js [data-reveal] { opacity: 1; transform: none; filter: none; transition: none; }
  .float { animation: none; }
  .scroll-cue::after { animation: none; }
  .m-orb { display: none; }
  .p-card, .f-card, .btn-solid { transition: none; }
}