/* =========================================================
   지피터스 랜딩 — style.css
   디자인 토큰: Claude Design '지피터스 디자인 시스템 v1' → 다크 翻案
   (오렌지 #eb5a10 + 보라→시안 그라디언트 + Noto Sans KR)
   ========================================================= */
:root {
  --gp-primary:        #eb5a10;
  --gp-primary-bright: #ff7a3c;
  --gp-accent:         #de6724;
  --gp-secondary:      #7e5700;
  --gp-grad-start:     #a345eb;
  --gp-grad-end:       #4fdff6;

  --bg:        #0a0a0f;
  --bg-soft:   #12121a;
  --surface:   #16161f;
  --text:      #f5f5f7;
  --text-dim:  rgba(245, 245, 247, 0.60);
  --text-mut:  rgba(245, 245, 247, 0.32);
  --line:      rgba(255, 255, 255, 0.10);

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-pill: 9999px;
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --dur: 0.3s;
  --max: 1200px;

  --grad-brand: linear-gradient(120deg, var(--gp-grad-start), var(--gp-grad-end));
  --grad-orange: linear-gradient(120deg, var(--gp-primary), var(--gp-accent));
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: auto; }
body {
  font-family: "Noto Sans KR", -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  letter-spacing: -0.01em;
  transition: background-color 0.6s var(--ease); /* 스크롤 배경색 전환 */
}
a { color: inherit; text-decoration: none; }
img, video { display: block; max-width: 100%; }

/* 호버 시 글자 팽창 (코드잇 fontbulger) */
.bulge { display: inline-block; transition: transform 0.3s var(--ease); }
.bulge:hover { transform: scale(1.15); }

/* 반짝임 스윕 (코드잇 shimmer) */
@keyframes shimmer { 0% { background-position: -200% 0; } 100% { background-position: 200% 0; } }
.shimmer { position: relative; overflow: hidden; }
.shimmer::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(120deg, transparent 30%, rgba(255,255,255,0.35) 50%, transparent 70%);
  background-size: 200% 100%; animation: shimmer 3.5s linear infinite; pointer-events: none;
}

/* =========================================================
   내비게이션
   ========================================================= */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  transition: background-color 0.4s var(--ease), backdrop-filter 0.4s var(--ease), border-color 0.4s var(--ease);
  border-bottom: 1px solid transparent;
}
.nav.is-scrolled { background: rgba(10,10,15,0.72); backdrop-filter: blur(12px); border-bottom-color: var(--line); }
.nav__inner { max-width: var(--max); margin: 0 auto; padding: 18px 24px; display: flex; align-items: center; justify-content: space-between; }
.nav__logo { font-weight: 900; letter-spacing: 0.06em; font-size: 20px; }
.nav__menu { display: flex; gap: 28px; list-style: none; }
.nav__menu a { color: var(--text-dim); font-size: 15px; transition: color 0.2s; }
.nav__menu a:hover { color: var(--text); }
.nav__cta {
  padding: 10px 18px; border-radius: var(--radius-pill);
  background: var(--gp-primary); color: #fff; font-weight: 700; font-size: 14px;
  transition: background 0.2s var(--ease), transform 0.2s var(--ease);
}
.nav__cta:hover { background: var(--gp-primary-bright); transform: translateY(-1px); }

/* =========================================================
   ① 히어로
   ========================================================= */
.hero { position: relative; height: 100vh; overflow: hidden; }
.hero__bg { position: absolute; inset: 0; z-index: 0; }
.hero__bg::before {
  content: ""; position: absolute; inset: -20%;
  background:
    linear-gradient(135deg, rgba(235,90,16,0.38) 0%, transparent 55%),
    linear-gradient(315deg, rgba(120,45,120,0.32) 0%, transparent 58%),
    radial-gradient(55% 55% at 60% 85%, rgba(222,103,36,0.18), transparent 62%),
    var(--bg);
  filter: blur(55px); animation: bgFloat 18s ease-in-out infinite alternate;
}
@keyframes bgFloat { from { transform: translate3d(-3%,-2%,0) scale(1.05); } to { transform: translate3d(3%,2%,0) scale(1.18); } }
.hero__video { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.hero__overlay { position: absolute; inset: 0; background: linear-gradient(180deg, rgba(10,10,15,0.35) 0%, rgba(10,10,15,0.15) 40%, rgba(10,10,15,0.9) 100%); }
.hero__content { position: relative; z-index: 2; height: 100%; }
.hero__line {
  position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center;
  text-align: center; padding: 0 24px; opacity: 0; will-change: transform, opacity, filter;
}
.hero__line--1 { opacity: 1; }
.hero__eyebrow { font-size: clamp(13px,1.4vw,16px); letter-spacing: 0.18em; color: var(--gp-primary-bright); margin-bottom: 20px; font-weight: 700; }
.hero__title { font-size: clamp(38px,7vw,92px); font-weight: 900; line-height: 1.1; letter-spacing: -0.03em; }
.hero__title--brand {
  font-size: clamp(64px,14vw,200px); letter-spacing: 0.02em;
  background: linear-gradient(120deg, #fff 12%, var(--gp-primary-bright) 42%, var(--gp-primary) 74%, var(--gp-accent) 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero__sub { margin-top: 24px; font-size: clamp(15px,2vw,20px); color: var(--text-dim); }

/* 라인1: 글자 세로 마스크 */
.char { display: inline-block; overflow: hidden; vertical-align: top; }
.char-inner { display: inline-block; will-change: transform; }
.char--space { width: 0.28em; }
/* 라인2: 좌우 슬라이드 조각 */
.hero__line--2 .hero__title { display: flex; flex-wrap: wrap; gap: 0.3em; justify-content: center; }
.slide-piece { display: inline-block; will-change: transform, opacity; }
/* 라인3: 스케일 줌 */
.hero__zoom { will-change: transform, opacity; }

.hero__scroll-hint { position: absolute; bottom: 32px; left: 50%; transform: translateX(-50%); z-index: 3; display: flex; flex-direction: column; align-items: center; gap: 10px; font-size: 11px; letter-spacing: 0.25em; color: var(--text-dim); }
.hero__scroll-line { width: 1px; height: 48px; background: linear-gradient(var(--text-dim), transparent); animation: scrollPulse 2s ease-in-out infinite; transform-origin: top; }
@keyframes scrollPulse { 0%,100% { transform: scaleY(0.4); opacity: 0.4; } 50% { transform: scaleY(1); opacity: 1; } }

/* =========================================================
   마퀴
   ========================================================= */
.marquee { background: var(--bg-soft); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); padding: 26px 0; overflow: hidden; white-space: nowrap; }
.marquee__track { display: inline-flex; align-items: center; gap: 28px; will-change: transform; }
.marquee__track span { font-size: clamp(20px,3vw,34px); font-weight: 700; color: var(--text); }
.marquee__track .dot { color: var(--gp-primary); font-size: 0.7em; }

/* =========================================================
   ② 공감 하이라이트
   ========================================================= */
.empathy { max-width: 900px; margin: 0 auto; padding: 200px 24px; text-align: center; }
.empathy__line { font-size: clamp(28px,5vw,56px); font-weight: 800; line-height: 1.35; letter-spacing: -0.02em; color: var(--text-mut); }
.empathy__line--strong { margin-top: 8px; }
/* 단어별 하이라이트: 기본 흐리게 → 스크롤에 따라 밝아짐
   (-webkit-text-fill-color를 currentColor로 명시해야 부모 상속에 안 덮임) */
.empathy__line .word { color: var(--text-mut); -webkit-text-fill-color: currentColor; transition: color 0.1s linear; }

/* =========================================================
   공통 섹션 헤더
   ========================================================= */
.section-head { text-align: center; margin-bottom: 56px; }
.section-head__eyebrow { font-size: 13px; letter-spacing: 0.2em; color: var(--gp-primary-bright); font-weight: 700; margin-bottom: 14px; }
.section-head__title, .study__title { font-size: clamp(26px,4vw,44px); font-weight: 900; letter-spacing: -0.02em; }
[data-reveal] { will-change: transform, opacity; }

/* =========================================================
   ③ 커뮤니티 카드 (3D 틸트)
   ========================================================= */
.features { max-width: var(--max); margin: 0 auto; padding: 120px 24px; }
.features__grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 24px; }
.feature-card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-md); padding: 40px 32px; transform-style: preserve-3d; transition: border-color 0.35s var(--ease), box-shadow 0.35s var(--ease); will-change: transform; }
.feature-card:hover { border-color: var(--gp-primary); box-shadow: 0 20px 60px rgba(235,90,16,0.18); }
.feature-card__icon {
  width: 56px; height: 56px; border-radius: 16px; margin-bottom: 24px;
  display: grid; place-items: center; transform: translateZ(30px);
  background: linear-gradient(135deg, rgba(235,90,16,0.16), rgba(222,103,36,0.04));
  border: 1px solid rgba(235,90,16,0.22);
}
.feature-card__icon svg { width: 28px; height: 28px; color: var(--gp-primary-bright); }
.feature-card h3 { font-size: 22px; font-weight: 700; margin-bottom: 12px; transform: translateZ(20px); }
.feature-card p { font-size: 16px; line-height: 1.65; color: var(--text-dim); transform: translateZ(12px); }

/* =========================================================
   ④ 스터디: 인트로 + 브라우저 목업(씬) + 가로 커리큘럼
   ========================================================= */
.study { padding: 120px 0; background: var(--bg-soft); border-top: 1px solid var(--line); }
.study__top { max-width: var(--max); margin: 0 auto 72px; padding: 0 24px; display: grid; grid-template-columns: 1.05fr 1fr; gap: 56px; align-items: center; }
.study__title { margin: 14px 0 24px; line-height: 1.12; }
.study__lead { font-size: clamp(16px,1.6vw,19px); line-height: 1.7; color: var(--text-dim); }
.study__lead strong { color: var(--gp-primary-bright); font-weight: 700; }
.study__meta { list-style: none; display: flex; flex-wrap: wrap; gap: 32px; margin-top: 32px; padding-top: 26px; border-top: 1px solid var(--line); }
.study__meta li { display: flex; flex-direction: column; gap: 6px; }
.study__meta span { font-size: 13px; color: var(--text-mut); letter-spacing: 0.05em; }
.study__meta strong { font-size: clamp(15px,1.6vw,18px); font-weight: 700; }

/* 브라우저 목업 (씬 순차 애니 대상) */
.mock { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-md); overflow: hidden; box-shadow: 0 30px 70px rgba(0,0,0,0.45); }
.mock__bar { display: flex; align-items: center; gap: 8px; padding: 12px 16px; background: #1e1e28; border-bottom: 1px solid var(--line); }
.mock__dot { width: 10px; height: 10px; border-radius: 50%; background: #3a3a46; }
.mock__url { margin-left: 10px; flex: 1; font-size: 12px; color: var(--text-mut); background: var(--bg); padding: 5px 14px; border-radius: var(--radius-pill); }
.mock__body { position: relative; padding: 44px 36px 52px; min-height: 260px; background: radial-gradient(70% 90% at 30% 20%, rgba(235,90,16,0.16), transparent 70%), var(--bg); }
.mock__eyebrow { color: var(--gp-primary-bright); font-size: 12px; font-weight: 700; letter-spacing: 0.1em; margin-bottom: 14px; }
.mock__title { font-size: clamp(24px,2.4vw,34px); font-weight: 900; line-height: 1.2; margin-bottom: 26px; }
.mock__btn { display: inline-block; padding: 11px 22px; background: var(--gp-primary); color: #fff; border-radius: var(--radius-pill); font-size: 14px; font-weight: 700; }
.mock__cursor { position: absolute; right: 90px; bottom: 70px; width: 18px; height: 18px; border-radius: 50%; background: rgba(255,255,255,0.95); box-shadow: 0 2px 10px rgba(0,0,0,0.5); pointer-events: none; }
.mock__cursor::after { content: ""; position: absolute; inset: -6px; border: 2px solid var(--gp-primary-bright); border-radius: 50%; opacity: 0; }

/* 가로 스크롤 커리큘럼 */
.study__track-wrap { overflow: hidden; }
.study__track { display: flex; gap: 24px; padding: 0 24px; width: max-content; }
.week-card { flex: 0 0 auto; width: 340px; min-height: 300px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-md); padding: 36px 32px; display: flex; flex-direction: column; }
.week-card__num { font-size: 13px; font-weight: 800; letter-spacing: 0.12em; color: var(--gp-primary-bright); margin-bottom: 20px; }
.week-card h3 { font-size: 26px; font-weight: 800; margin-bottom: 16px; line-height: 1.25; }
.week-card p { font-size: 15px; line-height: 1.7; color: var(--text-dim); }
.week-card--cta { background: var(--grad-orange); border: none; justify-content: center; align-items: flex-start; }
.week-card--cta h3 { color: #fff; }
.week-card__link { margin-top: 16px; font-weight: 700; color: #fff; }

/* =========================================================
   ⑤ 숫자 슬롯머신 + 막대
   ========================================================= */
.stats { background: var(--bg); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); padding: 120px 24px; }
.stats__grid { max-width: var(--max); margin: 0 auto; display: grid; grid-template-columns: repeat(4,1fr); gap: 24px; text-align: center; }
.stat { display: flex; flex-direction: column; gap: 12px; align-items: center; }
.stat__num { font-size: clamp(44px,6vw,80px); font-weight: 900; letter-spacing: -0.02em; line-height: 1; display: inline-flex; align-items: center; color: var(--gp-primary-bright); }
.reel { display: inline-block; height: 1em; overflow: hidden; vertical-align: bottom; }
.reel__strip { display: flex; flex-direction: column; will-change: transform; }
.reel__strip span { height: 1em; line-height: 1; }
.stat__label { font-size: 15px; color: var(--text-dim); }
/* 진행 막대 (growFromBottom 계열 — 왼→오로 채워짐) */
.stat__bar { width: 70%; max-width: 130px; height: 6px; background: var(--line); border-radius: var(--radius-pill); overflow: hidden; margin-top: 4px; }
.stat__bar i { display: block; height: 100%; width: 100%; background: var(--grad-orange); border-radius: var(--radius-pill); transform: scaleX(0); transform-origin: left; }

/* =========================================================
   ⑥ CTA
   ========================================================= */
.cta { position: relative; height: 100vh; display: flex; align-items: center; justify-content: center; text-align: center; overflow: hidden; background: #0a0810; }
/* 시안 5 — 듀오톤 대각 (오렌지 ↔ 딥 플럼) + 필름 그레인(::after) */
.cta::before {
  content: ""; position: absolute; inset: 0; z-index: 0;
  background:
    linear-gradient(135deg, rgba(235,90,16,0.24) 0%, transparent 48%),
    linear-gradient(315deg, rgba(120,45,120,0.22) 0%, transparent 48%);
}
/* 필름 그레인 — 고급 질감 */
.cta::after {
  content: ""; position: absolute; inset: 0; z-index: 1; pointer-events: none; opacity: 0.06; mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}
.cta__inner { position: relative; z-index: 2; padding: 0 24px; }
.cta__title { font-size: clamp(36px,7vw,88px); font-weight: 900; line-height: 1.1; letter-spacing: -0.03em; }
.cta__sub { margin: 24px 0 40px; font-size: clamp(16px,2vw,20px); color: var(--text-dim); }
.cta__button { display: inline-block; padding: 18px 44px; border-radius: var(--radius-pill); background: var(--gp-primary); color: #fff; font-weight: 700; font-size: 18px; transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease), background 0.25s var(--ease); box-shadow: 0 10px 40px rgba(235,90,16,0.4); }
.cta__button:hover { transform: translateY(-3px) scale(1.03); background: var(--gp-primary-bright); box-shadow: 0 16px 50px rgba(235,90,16,0.55); }

/* =========================================================
   푸터
   ========================================================= */
.footer { padding: 60px 24px; text-align: center; color: var(--text-dim); font-size: 14px; line-height: 1.8; }
.footer__dim { opacity: 0.6; font-size: 13px; }

/* =========================================================
   반응형
   ========================================================= */
@media (max-width: 768px) {
  .nav__menu { display: none; }
  .features__grid { grid-template-columns: 1fr; }
  .stats__grid { grid-template-columns: repeat(2,1fr); row-gap: 48px; }
  .empathy { padding: 130px 24px; }
  .features { padding: 80px 24px; }
  .study { padding: 80px 0; }
  .study__top { grid-template-columns: 1fr; gap: 36px; margin-bottom: 48px; }
  .study__meta { gap: 24px; }
  .week-card { width: 80vw; }
  .mock__cursor { right: 60px; }
}

/* =========================================================
   접근성: 모션 줄이기
   ========================================================= */
@media (prefers-reduced-motion: reduce) {
  .hero__bg::before, .hero__scroll-line, .shimmer::after { animation: none; }
  .hero__line { opacity: 1 !important; position: relative; }
  .empathy__line, .empathy__line .word { color: var(--text); -webkit-text-fill-color: var(--text); }
  .stat__bar i { transform: scaleX(1); }
  body { transition: none; }
}