:root { --bg: #F4F1EA; --ink: #23262D; --sub: #5F636C; --line: #E1DCD1; --white: #FFFEFB; }
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); color: var(--ink); font-family: 'BIZ UDPGothic', sans-serif; line-height: 1.8; -webkit-font-smoothing: antialiased; overflow-x: hidden; }
button { font: inherit; cursor: pointer; }
h1, h2, h3 { font-family: 'Zen Kaku Gothic New', sans-serif; }

.nav { position: sticky; top: 0; z-index: 50; display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 14px 32px; background: rgba(244,241,234,.94); border-bottom: 1px solid var(--line); }
.nav-logo { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font: 900 17px/1 'Zen Kaku Gothic New', sans-serif; letter-spacing: .06em; white-space: nowrap; }
.nav-logo small { font: 500 12px/1 'Outfit', sans-serif; letter-spacing: .14em; color: var(--sub); }
.nav-dot { width: 18px; height: 18px; border-radius: 50%; background: conic-gradient(#5b4fa3, #e0645a, #f0a51d, #3f8f68, #2d7bbd, #c25591, #8c8072, #5b4fa3); }
.nav nav { display: flex; gap: 22px; }
.nav nav a { color: var(--sub); text-decoration: none; font-size: 14px; }
.nav nav a:hover { color: var(--ink); }

.hero { display: grid; grid-template-columns: 1.05fr 1fr; gap: 40px; align-items: center; max-width: 1240px; margin: 0 auto; padding: 72px 32px 64px; }
.eyebrow { font: 600 12px/1 'Outfit', sans-serif; letter-spacing: .26em; color: var(--sub); margin: 0 0 22px; }
.hero h1 { font-size: 46px; line-height: 1.4; font-weight: 900; letter-spacing: .03em; margin: 0; }
.lead { margin: 24px 0 0; font-size: 16px; color: #3E424B; }
.lead b { color: var(--ink); }
.hero-legend { margin-top: 28px; display: flex; flex-wrap: wrap; gap: 8px 16px; }
.hero-legend span { display: inline-flex; align-items: center; gap: 7px; font-size: 13px; color: var(--sub); }
.hero-legend i { width: 12px; height: 12px; border-radius: 50%; }
.hero-note { margin-top: 26px; font-size: 12px; color: #8E929B; }
.hero-vis { position: relative; height: 520px; }
.hero-fan { position: absolute; left: 0; top: 30px; width: 100%; height: 420px; font-size: 2.7px; }
.hero-fan .card { position: absolute; left: 34%; top: 40px; transform-origin: 50% 160%; box-shadow: 0 10px 30px rgba(35,38,45,.16); transition: transform .5s; }
.hero-box { position: absolute; right: 2%; bottom: 0; }
.stage { perspective: 1400px; font-size: 2.4px; width: 70em; height: 95em; }
.box3d { position: relative; width: 70em; height: 95em; transform-style: preserve-3d; transform: rotateX(-18deg) rotateY(-34deg); transition: transform .8s cubic-bezier(.2,.7,.2,1); }
.box3d > .bf { position: absolute; left: 50%; top: 50%; backface-visibility: hidden; }
.box3d .face { box-shadow: inset 0 0 0 .2em rgba(0,0,0,.05); }
.box3d .bf.side .face { filter: brightness(.94); }
.box3d .bf.endf .face { filter: brightness(.98); }

.sec { max-width: 1240px; margin: 0 auto; padding: 88px 32px 40px; }
.sec-head { display: grid; grid-template-columns: auto 1fr; column-gap: 18px; align-items: baseline; margin-bottom: 36px; }
.sec-no { font: 300 44px/1 'Outfit', sans-serif; color: #A9A497; }
.sec-head h2 { margin: 0; font-size: 30px; font-weight: 900; letter-spacing: .05em; }
.sec-head p { grid-column: 2; margin: 8px 0 0; color: var(--sub); font-size: 15px; }

.concept { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.c-item { background: var(--white); border: 1px solid var(--line); border-radius: 14px; padding: 24px 22px; }
.c-item b { display: block; font: 700 17px/1.5 'Zen Kaku Gothic New', sans-serif; }
.c-item p { margin: 10px 0 0; font-size: 14px; color: #4A4E57; line-height: 1.85; }
.diff { margin-top: 36px; display: grid; grid-template-columns: 1fr auto 1fr; gap: 24px; align-items: center; background: var(--white); border: 1px solid var(--line); border-radius: 14px; padding: 28px; }
.diff-col small { display: block; font-size: 13px; color: var(--sub); margin-bottom: 14px; }
.diff-col p { margin: 14px 0 0; font-size: 13px; color: var(--sub); }
.diff-cards { display: flex; gap: 10px; font-size: 1.55px; height: 137px; align-items: flex-start; }
.dc { width: 98px; height: 137px; border-radius: 6px; background: #fff; border: 1px solid #DCD8CF; display: grid; place-items: center; font: 700 18px/1 'Zen Kaku Gothic New', sans-serif; color: #444; }
.diff-arrow { font: 300 32px/1 'Outfit', sans-serif; color: #A9A497; }

.tabs { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 26px; }
.tabs button { border: 1px solid var(--line); background: var(--white); color: var(--sub); border-radius: 99px; padding: 7px 16px; font-size: 13px; display: inline-flex; align-items: center; gap: 7px; }
.tabs button i { width: 10px; height: 10px; border-radius: 50%; }
.tabs button.on { background: var(--ink); color: #fff; border-color: var(--ink); }
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(183px, 1fr)); gap: 22px 18px; font-size: 2.9px; }
.flip { width: 63em; height: 88em; perspective: 900px; cursor: pointer; justify-self: center; }
.flip-in { position: relative; width: 100%; height: 100%; transform-style: preserve-3d; transition: transform .6s; }
.flip.is-flipped .flip-in { transform: rotateY(180deg); }
.flip .card { position: absolute; inset: 0; backface-visibility: hidden; box-shadow: 0 4px 14px rgba(35,38,45,.1); }
.flip .card.back-side { transform: rotateY(180deg); }
.flip:hover .flip-in { translate: 0 -4px; }
.anatomy { margin-top: 56px; display: grid; grid-template-columns: auto 1fr; gap: 48px; align-items: center; background: var(--white); border: 1px solid var(--line); border-radius: 14px; padding: 36px; }
.an-card { --u: 4.6px; font-size: var(--u); position: relative; }
.an-card .card { box-shadow: 0 10px 30px rgba(35,38,45,.15); }
.an-pin { position: absolute; left: calc(-3 * var(--u) - 12px); top: calc(var(--y) * var(--u) - 12px); width: 24px; height: 24px; border-radius: 50%; background: var(--ink); color: #fff; font: 600 12px/24px 'Outfit', sans-serif; text-align: center; box-shadow: 0 0 0 3px #fff; }
.an-list { margin: 0; padding: 0; list-style: none; counter-reset: a; display: grid; gap: 16px; }
.an-list li { counter-increment: a; position: relative; padding-left: 40px; font-size: 14px; color: #4A4E57; }
.an-list li::before { content: counter(a); position: absolute; left: 0; top: 0; width: 26px; height: 26px; border-radius: 50%; background: var(--ink); color: #fff; font: 600 13px/26px 'Outfit', sans-serif; text-align: center; }
.an-list b { display: block; color: var(--ink); font-size: 16px; }

.box-wrap { display: grid; grid-template-columns: 1fr 1.15fr; gap: 36px; align-items: start; }
.box-view { background: radial-gradient(circle at 50% 40%, #FFFEFB, #ECE7DC); border: 1px solid var(--line); border-radius: 14px; padding: 40px 20px 24px; display: flex; flex-direction: column; align-items: center; position: sticky; top: 80px; }
.stage.big { font-size: 3.6px; margin: 30px 0 50px; cursor: grab; touch-action: none; }
.box-btns { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; }
.box-btns button { border: 1px solid var(--line); background: var(--white); border-radius: 99px; padding: 6px 16px; font-size: 13px; }
.box-faces h3 { font-size: 16px; margin: 0 0 12px; letter-spacing: .05em; }
.box-faces h3:not(:first-child) { margin-top: 32px; }
.dieline-wrap { background: var(--white); border: 1px solid var(--line); border-radius: 14px; padding: 18px; overflow-x: auto; }
.dieline { position: relative; font-size: 2.85px; width: 186em; height: 211em; margin: 0 auto; }
.dl-face { position: absolute; }
.dl-glue { position: absolute; background: repeating-linear-gradient(45deg, #E7E2D7 0 1.5em, #F2EEE6 1.5em 3em); }
.dl-svg { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; overflow: visible; }
.dl-legend { font-size: 12px; color: var(--sub); display: flex; flex-wrap: wrap; gap: 4px 14px; align-items: center; }
.dl-legend span { display: inline-block; width: 22px; height: 0; margin-right: 4px; vertical-align: middle; }
.l-cut { border-top: 1.5px solid #23262D; }
.l-fold { border-top: 1.5px dashed #2d7bbd; }
.l-bleed { border-top: 1.5px dashed #e0645a; }
.l-glue { height: 10px !important; background: repeating-linear-gradient(45deg, #E7E2D7 0 3px, #F2EEE6 3px 6px); }
.back-face { font-size: 3.4px; display: inline-block; border-radius: 6px; overflow: hidden; box-shadow: 0 6px 20px rgba(35,38,45,.12); }

.manual-scroll { overflow-x: auto; padding: 30px 6px 40px; }
.manual { display: flex; font-size: 2.85px; width: max-content; margin: 0 auto; perspective: 1600px; }
.manual .card { border-radius: 0 !important; cursor: zoom-in; transition: transform .3s; box-shadow: 0 8px 22px rgba(35,38,45,.08); }
.manual .card:nth-child(odd) { transform: rotateY(7deg); transform-origin: right center; }
.manual .card:nth-child(even) { transform: rotateY(-7deg); transform-origin: left center; filter: brightness(.97); }
.manual .card:first-child { border-radius: 3em 0 0 3em !important; }
.manual .card:last-child { border-radius: 0 3em 3em 0 !important; }
.hint { text-align: center; color: #8E929B; font-size: 13px; margin: 0; }

.play { background: var(--white); border: 1px solid var(--line); border-radius: 14px; padding: 32px; }
.play-top { display: flex; gap: 28px; align-items: flex-end; flex-wrap: wrap; }
.pile { display: flex; flex-direction: column; align-items: center; gap: 10px; font-size: 1.9px; }
.pile-card { width: 63em; height: 88em; }
.pile-card:empty { border: 2px dashed var(--line); border-radius: 3em; }
.pile button, .play-actions button { border: 1px solid var(--ink); background: var(--white); border-radius: 99px; padding: 6px 16px; font-size: 13px; color: var(--ink); }
.pile button:disabled { opacity: .35; cursor: default; }
.pile small { font-size: 12px; color: var(--sub); }
.play-msg { flex: 1; min-width: 240px; align-self: center; font-size: 15px; background: #F4F1EA; border-radius: 12px; padding: 16px 20px; }
.play-msg b { font-family: 'Zen Kaku Gothic New', sans-serif; }
.hand { margin-top: 28px; display: flex; gap: 14px; flex-wrap: wrap; font-size: 2.5px; min-height: 230px; }
.hand .card { cursor: pointer; transition: transform .2s, box-shadow .2s; box-shadow: 0 4px 14px rgba(35,38,45,.1); }
.hand.must .card:hover { transform: translateY(-10px); box-shadow: 0 0 0 2px #e0645a, 0 14px 24px rgba(35,38,45,.15); }
.hand .card.is-new { box-shadow: 0 0 0 2.5px var(--ink), 0 8px 18px rgba(35,38,45,.15); }
.play-actions { margin-top: 22px; display: flex; gap: 10px; justify-content: flex-end; }
.play-actions .solid { background: var(--ink); color: #fff; }
.play-result { display: none; margin-top: 26px; padding-top: 26px; border-top: 1px dashed var(--line); }
.play-result.on { display: grid; grid-template-columns: auto 1fr; gap: 28px; align-items: center; }
.play-result .qwrap { font-size: 2.5px; }
.pr-palette { display: flex; height: 54px; border-radius: 10px; overflow: hidden; margin: 10px 0 14px; }
.pr-palette i { flex: 1; }
.play-result h3 { margin: 0; font-size: 20px; }
.play-result p { margin: 0; color: var(--sub); font-size: 14px; }

.spec { display: grid; grid-template-columns: 1.6fr 1fr; gap: 24px; align-items: start; }
.spec table { width: 100%; border-collapse: collapse; background: var(--white); border-radius: 14px; overflow: hidden; border: 1px solid var(--line); }
.spec th, .spec td { text-align: left; padding: 16px 20px; border-bottom: 1px solid var(--line); font-size: 14px; vertical-align: top; }
.spec th { width: 110px; background: #F8F6F0; font-weight: 700; white-space: nowrap; }
.spec small { color: #8E929B; font-size: 12px; }
.spec tr:last-child th, .spec tr:last-child td { border-bottom: 0; }
.pdf-link { display: block; background: var(--ink); color: #fff; text-decoration: none; border-radius: 14px; padding: 24px 24px 26px; }
.pdf-link b { display: block; font: 700 18px/1.4 'Zen Kaku Gothic New', sans-serif; }
.pdf-link b::after { content: ' ↗'; font-family: 'Outfit', sans-serif; }
.pdf-link span { display: block; margin-top: 8px; font-size: 13px; opacity: .78; }
.small-note { font-size: 12px; color: #8E929B; }

.foot { margin-top: 80px; padding: 48px 32px 56px; border-top: 1px solid var(--line); text-align: center; color: var(--sub); font-size: 13px; }
.foot .sig { font: 700 15px/1 'Zen Kaku Gothic New', sans-serif; color: var(--ink); letter-spacing: .1em; margin-top: 24px; }

.modal { position: fixed; inset: 0; z-index: 100; background: rgba(28,30,35,.72); display: none; place-items: center; padding: 24px; cursor: zoom-out; }
.modal.on { display: grid; }
.modal-in { font-size: 6.4px; }
.modal-in .card { border-radius: 3em; box-shadow: 0 20px 60px rgba(0,0,0,.4); }

@media (max-width: 1000px) {
  .hero { grid-template-columns: 1fr; padding-top: 48px; }
  .hero-vis { height: 460px; }
  .concept { grid-template-columns: 1fr 1fr; }
  .box-wrap { grid-template-columns: 1fr; }
  .box-view { position: static; }
  .spec { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .nav { padding: 12px 16px; }
  .nav nav { display: none; }
  .hero, .sec { padding-left: 16px; padding-right: 16px; }
  .hero h1 { font-size: 30px; }
  .hero-vis { height: 380px; }
  .hero-fan { font-size: 2px; }
  .stage { font-size: 1.8px; }
  .concept { grid-template-columns: 1fr; }
  .diff { grid-template-columns: 1fr; }
  .diff-arrow { transform: rotate(90deg); justify-self: center; }
  .card-grid { grid-template-columns: repeat(2, 1fr); font-size: 2.45px; gap: 16px 12px; }
  .anatomy { grid-template-columns: 1fr; justify-items: center; padding: 24px 18px; }
  .an-card { --u: 3.6px; }
  .stage.big { font-size: 2.8px; }
  .dieline { font-size: 1.7px; }
  .play { padding: 20px 16px; }
  .pile { font-size: 1.4px; }
  .hand { font-size: 1.9px; gap: 8px; }
  .play-result.on { grid-template-columns: 1fr; }
  .modal-in { font-size: 4.8px; }
  .sec-head { grid-template-columns: 1fr; }
  .sec-head p { grid-column: 1; }
}