/* =========================================================
   지피터스 랜딩 — style.css (v2)
   디자인 토큰: Claude Design '지피터스 디자인 시스템 v1' → 다크 翻案
   ========================================================= */
: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; }
a { color: inherit; text-decoration: none; }
img, video { display: block; max-width: 100%; }

/* 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); }

/* 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: radial-gradient(55% 55% at 25% 30%, rgba(235,90,16,0.55), transparent 60%), radial-gradient(50% 50% at 80% 35%, rgba(163,69,235,0.45), transparent 60%), radial-gradient(55% 55% at 60% 80%, rgba(79,223,246,0.35), transparent 60%), var(--bg); filter: blur(50px); 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 15%, var(--gp-grad-start) 55%, var(--gp-grad-end) 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); }
.char { display: inline-block; overflow: hidden; vertical-align: top; }
.char-inner { display: inline-block; will-change: transform; }
.char--space { width: 0.28em; }
.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; }

/* 공감 하이라이트 */
.empathy { max-width: 1000px; margin: 0 auto; padding: 200px 24px; }
.empathy__text { font-size: clamp(26px,4.4vw,52px); font-weight: 800; line-height: 1.45; letter-spacing: -0.02em; text-align: center; }
.empathy__text .word { color: var(--text-mut); transition: color 0.1s linear; }

/* 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; }

/* 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 { font-size: 40px; margin-bottom: 20px; transform: translateZ(30px); }
.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); }

/* 스터디: 인트로 + 가로 커리큘럼 */
.study { padding: 120px 0; background: var(--bg-soft); border-top: 1px solid var(--line); }
.study__intro { max-width: var(--max); margin: 0 auto 64px; padding: 0 24px; }
.study__title { margin: 14px 0 24px; line-height: 1.12; }
.study__lead { max-width: 640px; font-size: clamp(16px,2vw,20px); 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: 40px; margin-top: 36px; padding-top: 28px; 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(16px,2vw,19px); font-weight: 700; }
.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; }

/* 숫자 슬롯머신 */
.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); }

/* CTA */
.cta { position: relative; height: 100vh; display: flex; align-items: center; justify-content: center; text-align: center; overflow: hidden; background: radial-gradient(60% 80% at 50% 30%, rgba(235,90,16,0.3), transparent 70%), var(--bg); }
.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__meta { gap: 24px; }
  .week-card { width: 78vw; }
  .study__track-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; }
}

/* 접근성 */
@media (prefers-reduced-motion: reduce) {
  .hero__bg::before, .hero__scroll-line { animation: none; }
  .hero__line { opacity: 1 !important; position: relative; }
  .empathy__text .word { color: var(--text); }
}