/* ===================================================================
   Biber studio (비버스튜디오) — AI 숏폼 스튜디오 랜딩  v3
   Toss-inspired: 차분한 단색 블루 · 넓은 여백 · 절제된 그림자
=================================================================== */

:root {
  --blue:        #3182F6;   /* 메인 블루 (Toss-tone) */
  --blue-strong: #1B64DA;
  --blue-press:  #1957C2;
  --blue-tint:   #E8F1FF;   /* 옅은 블루 타일 */

  --ink:    #191F28;        /* 본문 (near-black) */
  --muted:  #4E5968;        /* 보조 */
  --gray:   #8B95A1;        /* 옅은 회색 */

  --bg:     #FFFFFF;
  --soft:   #F7F8FA;        /* 옅은 섹션 */
  --soft2:  #F2F4F6;
  --line:   #E5E8EB;

  --radius:    14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --shadow:    0 2px 8px rgba(17, 24, 39, 0.04), 0 1px 2px rgba(17,24,39,.04);
  --shadow-md: 0 8px 24px rgba(17, 24, 39, 0.07);
  --shadow-lg: 0 16px 40px rgba(17, 24, 39, 0.10);
  --maxw: 1140px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Pretendard', system-ui, -apple-system, sans-serif;
  color: var(--ink); background: var(--bg); line-height: 1.65;
  -webkit-font-smoothing: antialiased; overflow-x: hidden; letter-spacing: -0.01em;
}
.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
a { color: inherit; text-decoration: none; }
.accent { color: var(--blue); }

/* ===== Buttons ===== */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 9px;
  padding: 15px 28px; border-radius: var(--radius);
  font-weight: 700; font-size: 1rem; cursor: pointer; border: 1.5px solid transparent;
  transition: transform .2s var(--ease), box-shadow .25s var(--ease), background .18s, color .18s, border-color .18s;
  white-space: nowrap; line-height: 1;
}
.btn .arrow { display: inline-block; transition: transform .2s var(--ease); font-weight: 800; }
.btn:hover .arrow { transform: translateX(4px); }

/* 1차 CTA — 입체감 있는 블루 */
.btn--primary { background: linear-gradient(180deg, #4A90FF 0%, #3182F6 100%); color: #fff; box-shadow: 0 8px 18px rgba(49,130,246,.32), inset 0 1px 0 rgba(255,255,255,.25); }
.btn--primary:hover { background: linear-gradient(180deg, #3D86FB 0%, #1B64DA 100%); transform: translateY(-2px); box-shadow: 0 12px 26px rgba(49,130,246,.42), inset 0 1px 0 rgba(255,255,255,.2); }
.btn--primary:active { transform: translateY(0); }

/* 2차 CTA — 채워진 옅은 블루 (테두리만 X → 더 버튼답게) */
.btn--soft { background: var(--blue-tint); color: var(--blue-strong); }
.btn--soft:hover { background: #D6E6FF; transform: translateY(-2px); box-shadow: 0 6px 16px rgba(49,130,246,.16); }

.btn--ghost { background: #fff; color: var(--ink); border-color: var(--line); box-shadow: var(--shadow); }
.btn--ghost:hover { border-color: var(--blue); color: var(--blue); transform: translateY(-2px); box-shadow: var(--shadow-md); }

.btn--block { width: 100%; }
.btn--lg { padding: 17px 34px; font-size: 1.06rem; }

.btn--kakao { background: #FEE500; color: #341B1B; box-shadow: 0 8px 18px rgba(254,229,0,.3); }
.btn--kakao:hover { background: #ffe94d; transform: translateY(-2px); box-shadow: 0 12px 24px rgba(254,229,0,.42); }
.btn--insta { background: linear-gradient(105deg,#F58529,#DD2A7B 50%,#8134AF 80%); color:#fff; box-shadow: 0 8px 18px rgba(221,42,123,.26); }
.btn--insta:hover { transform: translateY(-2px); box-shadow: 0 12px 24px rgba(221,42,123,.36); }

/* ===== Brand ===== */
.brand { display: inline-flex; align-items: center; }
.brand__logo { height: 28px; width: auto; display: block; }
.footer__logo { height: 28px; width: auto; display: block; }

/* ===== NAV ===== */
.nav {
  position: fixed; inset: 0 0 auto 0; z-index: 100;
  background: rgba(255, 255, 255, 0.8); backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid transparent; transition: border-color .3s, box-shadow .3s;
}
.nav.scrolled { border-bottom-color: var(--line); }
.nav__inner { display: flex; align-items: center; justify-content: space-between; height: 70px; }
.nav__links { display: flex; align-items: center; gap: 30px; }
.nav__links a { font-weight: 600; color: var(--muted); font-size: 0.96rem; transition: color .18s; }
.nav__links a:not(.nav__cta):hover { color: var(--ink); }
.nav__cta { background: var(--blue); color: #fff !important; padding: 10px 20px; border-radius: var(--radius); box-shadow: 0 4px 12px rgba(49,130,246,.24); transition: background .18s, transform .18s; }
.nav__cta:hover { background: var(--blue-strong); transform: translateY(-1px); }

.nav__toggle { display: none; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav__toggle span { width: 23px; height: 2.5px; background: var(--ink); border-radius: 2px; transition: transform .3s, opacity .3s; }
.nav__toggle.open span:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
.nav__toggle.open span:nth-child(2) { opacity: 0; }
.nav__toggle.open span:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }

/* ===== HERO (light, Toss-calm) ===== */
.hero {
  position: relative; overflow: hidden; text-align: center;
  padding: 160px 0 96px;
  background:
    radial-gradient(680px 380px at 50% -8%, #EAF2FE 0%, rgba(234,242,254,0) 70%),
    var(--bg);
}
.hero__inner { position: relative; z-index: 2; max-width: 800px; margin: 0 auto; }
.hero__logo { height: 56px; width: auto; margin: 0 auto 26px; display: block; }
.hero__badge {
  display: inline-flex; align-items: center; gap: 8px; font-size: 0.85rem; font-weight: 700;
  padding: 8px 16px; border-radius: 999px; margin-bottom: 24px;
  background: var(--blue-tint); color: var(--blue-strong);
}
.hero__badge b { font-weight: 800; }
.hero__title { font-size: clamp(2.1rem, 5.4vw, 3.5rem); font-weight: 800; line-height: 1.22; letter-spacing: -0.035em; color: var(--ink); }
.hero__title .accent { color: var(--blue); }
.hero__sub { margin: 22px auto 0; font-size: clamp(1.05rem, 2.3vw, 1.22rem); color: var(--muted); max-width: 560px; }
.hero__actions { margin-top: 36px; display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* Hero 쇼케이스 — 실제 작업 포스터 클러스터 */
.hero__showcase { margin-top: 64px; display: flex; justify-content: center; align-items: flex-end; gap: 16px; }
.shot {
  position: relative; width: clamp(108px, 15vw, 158px); aspect-ratio: 9 / 16; border-radius: 20px; overflow: hidden;
  border: 5px solid #fff; background: var(--soft2); box-shadow: var(--shadow-lg);
  transition: transform .35s var(--ease);
}
.shot img { width: 100%; height: 100%; object-fit: cover; display: block; }
.shot::after { content: "▶"; position: absolute; top: 50%; left: 50%; transform: translate(-50%,-50%);
  width: 40px; height: 40px; border-radius: 50%; background: rgba(255,255,255,.92); color: var(--blue);
  display: flex; align-items: center; justify-content: center; font-size: .8rem; padding-left: 2px; box-shadow: 0 4px 12px rgba(0,0,0,.18); }
.shot--a { transform: rotate(-7deg) translateY(14px); z-index: 1; }
.shot--b { transform: rotate(-3deg) translateY(4px); z-index: 2; }
.shot--c { transform: rotate(3deg) translateY(4px); z-index: 2; }
.shot--d { transform: rotate(7deg) translateY(14px); z-index: 1; }
.hero__showcase:hover .shot { transform: rotate(0) translateY(0); }

/* ===== Credibility band (Kmong proof) ===== */
.proof { background: var(--bg); padding: 8px 0 36px; }
.proof__grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.proof__item {
  text-align: center; padding: 26px 14px; background: var(--soft); border: 1px solid var(--line);
  border-radius: var(--radius-lg); transition: transform .25s var(--ease), box-shadow .25s var(--ease);
}
.proof__item:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.proof__item strong { display: block; font-size: clamp(1.7rem, 3.6vw, 2.4rem); font-weight: 800; color: var(--ink); line-height: 1; letter-spacing: -0.03em; }
.proof__item strong .u { color: var(--blue); }
.proof__item span { display: block; margin-top: 10px; font-size: 0.92rem; color: var(--muted); font-weight: 500; }
.proof__note { margin-top: 22px; text-align: center; font-size: 0.9rem; color: var(--gray); }
.proof__note b { color: var(--blue-strong); font-weight: 700; }

/* ===== Sections ===== */
.section { padding: 100px 0; position: relative; }
.section--alt { background: var(--soft); }
.section__head { max-width: 660px; }
.section__head--center { margin: 0 auto; text-align: center; }
.eyebrow { display: inline-block; font-size: 0.78rem; font-weight: 800; letter-spacing: .08em; color: var(--blue-strong); margin-bottom: 16px; padding: 7px 14px; border-radius: 999px; background: var(--blue-tint); }
.section__title { font-size: clamp(1.7rem, 3.8vw, 2.5rem); font-weight: 800; letter-spacing: -0.035em; line-height: 1.25; color: var(--ink); }
.section__lead { margin-top: 14px; color: var(--muted); font-size: 1.08rem; }

/* ===== Service cards ===== */
.cards { margin-top: 48px; display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.card {
  position: relative; background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 32px 26px; box-shadow: var(--shadow); overflow: hidden;
  transition: transform .28s var(--ease), box-shadow .28s var(--ease), border-color .25s;
}
.card::before { content: ""; position: absolute; left: 0; right: 0; top: 0; height: 3px; background: var(--blue); transform: scaleX(0); transform-origin: left; transition: transform .3s var(--ease); }
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-md); border-color: #D6E2F5; }
.card:hover::before { transform: scaleX(1); }
.card__icon {
  width: 56px; height: 56px; border-radius: var(--radius); background: var(--blue-tint);
  display: flex; align-items: center; justify-content: center; font-size: 1.6rem; margin-bottom: 18px;
  transition: transform .28s var(--ease);
}
.card:hover .card__icon { transform: scale(1.08) rotate(-3deg); }
.card h3 { font-size: 1.17rem; font-weight: 700; margin-bottom: 8px; }
.card p { color: var(--muted); font-size: 0.96rem; }

/* ===== Why ===== */
.why { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 60px; align-items: center; }
.why__list { list-style: none; margin: 28px 0 34px; display: grid; gap: 16px; }
.why__list li { position: relative; padding-left: 34px; color: var(--muted); font-size: 1.03rem; }
.why__list li::before {
  content: "✓"; position: absolute; left: 0; top: 1px;
  width: 24px; height: 24px; border-radius: 8px; background: var(--blue-tint); color: var(--blue);
  font-size: 0.8rem; font-weight: 800; display: flex; align-items: center; justify-content: center;
}
.why__list strong { color: var(--ink); }
.why__visual { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.why__card {
  display: flex; flex-direction: column; gap: 6px; justify-content: center; align-items: flex-start;
  border-radius: var(--radius-lg); padding: 26px 24px; min-height: 144px; font-weight: 800; border: 1px solid var(--line);
}
.why__card b { font-size: 1.15rem; }
.why__card small { font-weight: 500; font-size: 0.85rem; color: var(--muted); }
.why__card--1 { background: #fff; color: var(--blue); transform: translateY(16px); box-shadow: var(--shadow); }
.why__card--2 { background: var(--blue); color: #fff; border-color: transparent; }
.why__card--2 small { color: rgba(255,255,255,.82); }
.why__card--3 { background: var(--ink); color: #fff; border-color: transparent; transform: translateY(16px); }
.why__card--3 small { color: rgba(255,255,255,.72); }
.why__card--4 { background: #fff; color: var(--blue); box-shadow: var(--shadow); }

/* ===== Steps ===== */
.steps { margin-top: 48px; display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.step {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 30px 26px; box-shadow: var(--shadow); transition: transform .25s var(--ease), box-shadow .25s var(--ease);
}
.step:hover { transform: translateY(-5px); box-shadow: var(--shadow-md); }
.step__num {
  display: inline-flex; align-items: center; justify-content: center; width: 42px; height: 42px; border-radius: 12px;
  background: var(--blue-tint); color: var(--blue); font-size: 1.05rem; font-weight: 800; margin-bottom: 16px;
}
.step h3 { font-size: 1.12rem; margin-bottom: 6px; }
.step p { color: var(--muted); font-size: 0.95rem; }

/* ===== Videos / Portfolio ===== */
.videos { margin-top: 48px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; grid-auto-flow: dense; }
.video { padding: 0; border: 0; background: none; cursor: pointer; text-align: left; font: inherit; }
.video--h { grid-column: span 2; }
.video__frame {
  position: relative; width: 100%; aspect-ratio: 9 / 16; border-radius: var(--radius-lg);
  overflow: hidden; background: var(--soft2); box-shadow: var(--shadow); border: 1px solid var(--line);
  transition: transform .28s var(--ease), box-shadow .28s var(--ease);
}
.video--h .video__frame { aspect-ratio: 16 / 9; }
.video:hover .video__frame { transform: translateY(-5px); box-shadow: var(--shadow-md); }
.video__poster { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; display: block; transition: transform .5s var(--ease); }
.video:hover .video__poster { transform: scale(1.04); }
.video__frame--empty .video__poster { display: none; }
.video__play {
  position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%) scale(.92);
  width: 56px; height: 56px; border-radius: 50%; background: rgba(255,255,255,.95); color: var(--blue);
  display: flex; align-items: center; justify-content: center; font-size: 1.15rem; padding-left: 3px;
  box-shadow: 0 6px 18px rgba(0,0,0,.22); transition: transform .25s var(--ease); z-index: 2;
}
.video:hover .video__play { transform: translate(-50%, -50%) scale(1.04); }
.video__label {
  position: absolute; left: 0; right: 0; bottom: 0; z-index: 2;
  padding: 30px 16px 14px; color: #fff; font-size: 0.85rem; line-height: 1.4;
  background: linear-gradient(transparent, rgba(15,23,40,.82)); display: flex; flex-direction: column; gap: 1px;
}
.video__label strong { font-size: 1.02rem; font-weight: 800; }
.video__label span { opacity: .85; }
.work__cta { margin-top: 42px; display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* ===== Lightbox ===== */
.lightbox {
  position: fixed; inset: 0; z-index: 200; display: none;
  align-items: center; justify-content: center; padding: 24px;
  background: rgba(15, 23, 40, 0.8); backdrop-filter: blur(6px);
}
.lightbox.open { display: flex; animation: lbFade .22s var(--ease); }
@keyframes lbFade { from { opacity: 0; } to { opacity: 1; } }
.lightbox__stage { display: flex; flex-direction: column; align-items: center; gap: 14px; max-width: 100%; }
.lightbox__stage video { max-height: 82vh; max-width: 100%; width: auto; border-radius: 16px; box-shadow: 0 24px 70px rgba(0,0,0,.45); background: #000; }
.lightbox__caption { color: rgba(255,255,255,.85); font-size: 0.95rem; font-weight: 600; }
.lightbox__close {
  position: absolute; top: 20px; right: 24px; width: 44px; height: 44px; border-radius: 50%;
  background: rgba(255,255,255,.14); color: #fff; border: 0; font-size: 1.8rem; line-height: 1; cursor: pointer;
  transition: background .2s, transform .3s;
}
.lightbox__close:hover { background: rgba(255,255,255,.26); transform: rotate(90deg); }

/* ===== CTA band ===== */
.cta { padding: 30px 0 100px; }
.cta__inner {
  border-radius: var(--radius-xl); text-align: center; color: #fff;
  padding: 70px 32px; background: var(--blue); box-shadow: 0 20px 50px rgba(49,130,246,.26);
}
.cta__inner h2 { font-size: clamp(1.6rem, 3.6vw, 2.4rem); font-weight: 800; letter-spacing: -0.03em; }
.cta__inner p { margin: 14px auto 0; color: rgba(255,255,255,.92); max-width: 520px; font-size: 1.06rem; }
.cta__actions { margin-top: 32px; display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.cta .btn--white { background: #fff; color: var(--blue-strong); }
.cta .btn--white:hover { background: #F2F4F6; transform: translateY(-2px); }
.cta .btn--ghost { background: transparent; color: #fff; border-color: rgba(255,255,255,.5); }
.cta .btn--ghost:hover { background: rgba(255,255,255,.12); border-color: #fff; color: #fff; }

/* ===== Contact ===== */
.contact { display: grid; grid-template-columns: 1fr 1.1fr; gap: 56px; align-items: start; }
.contact__channels { display: flex; flex-wrap: wrap; gap: 10px; margin: 24px 0 26px; }
.contact__info { list-style: none; display: grid; gap: 12px; color: var(--muted); }
.contact__info a { color: var(--blue); font-weight: 600; }
.contact__form {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius-xl);
  padding: 36px; box-shadow: var(--shadow-md); display: grid; gap: 16px;
}
.field { display: grid; gap: 7px; }
.field label { font-size: 0.9rem; font-weight: 600; color: var(--ink); }
.field input, .field textarea {
  width: 100%; padding: 13px 15px; border: 1.5px solid var(--line); border-radius: 12px;
  font-family: inherit; font-size: 0.98rem; color: var(--ink); background: var(--soft);
  transition: border-color .18s, box-shadow .18s, background .18s;
}
.field input:focus, .field textarea:focus { outline: none; border-color: var(--blue); box-shadow: 0 0 0 3px rgba(49,130,246,.14); background: #fff; }
.field textarea { resize: vertical; }
.form__status { font-size: 0.92rem; text-align: center; min-height: 1.2em; }
.form__status.ok { color: #16a34a; }
.form__status.err { color: #dc2626; }

/* ===== Footer ===== */
.footer { background: var(--soft); border-top: 1px solid var(--line); padding: 48px 0 40px; }
.footer__inner { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 18px; }
.footer__copy { font-size: 0.88rem; color: var(--gray); }
.footer__links { display: flex; gap: 22px; }
.footer__links a { font-weight: 600; font-size: 0.9rem; color: var(--muted); transition: color .18s; }
.footer__links a:hover { color: var(--blue); }

/* ===== Reveal ===== */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.in { opacity: 1; transform: none; }

/* ===================================================================
   Responsive
=================================================================== */
@media (max-width: 980px) {
  .cards, .steps { grid-template-columns: repeat(2, 1fr); }
  .why, .contact { grid-template-columns: 1fr; gap: 44px; }
  .videos { grid-template-columns: repeat(2, 1fr); }
  .proof__grid { grid-template-columns: repeat(2, 1fr); gap: 8px; }
}
@media (max-width: 680px) {
  .nav__links {
    position: fixed; inset: 70px 0 auto 0; flex-direction: column; gap: 0;
    background: #fff; border-bottom: 1px solid var(--line);
    padding: 8px 0; transform: translateY(-135%); transition: transform .32s var(--ease); box-shadow: var(--shadow-lg);
  }
  .nav__links.open { transform: translateY(0); }
  .nav__links a { width: 100%; padding: 15px 24px; }
  .nav__cta { margin: 8px 24px; text-align: center; }
  .nav__toggle { display: flex; }

  .section { padding: 72px 0; }
  .hero { padding: 134px 0 80px; }
  .hero__showcase { margin-top: 48px; gap: 10px; }
  .shot--a, .shot--d { display: none; }
  .shot { width: clamp(120px, 40vw, 150px); }
  .cards, .steps, .videos { grid-template-columns: 1fr; }
  .video--h { grid-column: auto; }
  .why__visual { grid-template-columns: 1fr 1fr; }
  .cta__inner { padding: 54px 22px; }
  .contact__form { padding: 26px; }
}