/* 볼트와너트 본 사이트 공통 스타일 v3 (2026-10-27, v2에서 휴대폰 조립도 240px·첫 화면 약속 문구 글꼴). 배포 후 수정 금지 — 바꿀 일은 v4 폴더로.
   콘셉트: 청사진 위의 조립도. 밝은·어두운 설정과 상관없이 늘 청사진으로 보인다. 마스코트 '너티'가 안내한다. */

:root {
  --paper: #0b1826; --sheet: #102235; --ink: #e6eef5; --ink-2: #aec1d1; --ink-3: #8aa3b8;
  --line: #2f4a63; --line-2: #4f6f8c; --grid: rgb(174 193 209 / .07);
  --red: #ff9466; --red-tint: rgb(255 148 102 / .1); --on-red: #0b1826;
  --font: "Pretendard", "Apple SD Gothic Neo", "Noto Sans KR", "Noto Sans CJK KR", "Malgun Gothic", system-ui, sans-serif;
  --mono: ui-monospace, "SF Mono", "D2Coding", Menlo, Consolas, "Liberation Mono", monospace;
  --gutter: 16px; --bar-h: 56px;
  color-scheme: dark;
}
@media (min-width: 960px) { :root { --gutter: 32px; --bar-h: 64px; } }

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; min-height: 100vh; display: flex; flex-direction: column;
  background: var(--paper); color: var(--ink);
  font: 400 16px/1.65 var(--font); letter-spacing: -0.01em; word-break: keep-all; overflow-wrap: anywhere;
}
main { flex: 1; }
h1, h2, h3, p, ul, ol, dl, dd, figure { margin: 0; }
ul, ol { padding: 0; list-style: none; }
a { color: inherit; }
img, svg { display: block; }
:focus-visible { outline: 2px solid var(--red); outline-offset: 3px; border-radius: 2px; }
.vh { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip:focus { position: fixed !important; top: 8px; left: 8px; width: auto; height: auto; clip: auto; z-index: 40; padding: 8px 16px; background: var(--sheet); border: 1.5px solid var(--red); }
.wrap { max-width: 1200px; margin: 0 auto; padding: 0 var(--gutter); }
.mono { font-family: var(--mono); letter-spacing: 0; }

/* 1. 상단 줄 */
.bar { position: sticky; top: 0; z-index: 30; background: var(--paper); border-bottom: 1px solid var(--ink); }
.bar .wrap { height: var(--bar-h); display: flex; align-items: center; gap: 16px; }
.logo { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; font-weight: 800; font-size: 19px; letter-spacing: -0.04em; min-height: 44px; }
.logo svg { width: 30px; height: 30px; }
.logo small { font: 500 14px/1 var(--mono); color: var(--ink-3); letter-spacing: 0; display: none; }
@media (min-width: 640px) { .logo small { display: inline; } }
.menu { margin-left: auto; display: flex; gap: 4px; }
.menu a { display: inline-flex; align-items: center; min-height: 44px; padding: 0 10px; font-size: 15px; font-weight: 600; color: var(--ink-2); text-decoration: none; }
.menu a:hover, .menu a[aria-current="page"] { color: var(--ink); text-decoration: underline; text-decoration-color: var(--red); text-decoration-thickness: 2px; text-underline-offset: 6px; }
@media (max-width: 380px) { .menu a { padding: 0 7px; } }

/* 2. 첫 화면 머리 */
.lede { padding: 40px 0 28px; border-bottom: 1px solid var(--line); }
.lede .wrap { display: grid; gap: 16px; }
.eyebrow { font: 600 14px/1.4 var(--mono); color: var(--red); letter-spacing: .02em; }
.lede h1 { font-size: 34px; line-height: 1.22; font-weight: 800; letter-spacing: -0.045em; max-width: 18em; }
.lede p { color: var(--ink-2); max-width: 36em; }
.lede-body { display: grid; gap: 18px; }
.quick { display: flex; flex-wrap: wrap; gap: 8px; }
.quick a { display: inline-flex; align-items: center; gap: 6px; min-height: 44px; padding: 0 14px; border: 1.5px solid var(--ink); background: var(--sheet); color: var(--ink); font-size: 15px; font-weight: 700; text-decoration: none; letter-spacing: -0.02em; box-shadow: 3px 3px 0 var(--line-2); transition: transform .15s, box-shadow .15s, background .15s; }
.quick a::after { content: "↗"; color: var(--red); font-weight: 700; }
.quick a:hover { background: var(--red); color: var(--on-red); transform: translate(-1px, -1px); box-shadow: 4px 4px 0 var(--ink); }
.quick a:hover::after { color: var(--on-red); }
.quick li:first-child a { background: var(--ink); color: var(--sheet); }
.quick li:first-child a:hover { background: var(--red); color: var(--on-red); }
.lede .promise { font-size: 14px; line-height: 1.6; color: var(--ink-3); }
@media (min-width: 960px) {
  .lede { padding: 64px 0 40px; }
  .lede .wrap { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); align-items: end; column-gap: 48px; }
  .lede .eyebrow { grid-column: 1 / -1; }
  .lede h1 { font-size: 56px; }
}

/* 3. 조립도 무대(프레젠테이션식 확대) */
.stage { position: relative; border-bottom: 1px solid var(--ink); background-color: var(--paper);
  background-image: linear-gradient(var(--grid) 1px, transparent 1px), linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 24px 24px; }
.plane { position: relative; width: min(760px, 100%); margin: 0 auto; padding: 24px var(--gutter) 40px; }
.art-wide { display: none; }
.art-tall { width: 100%; height: auto; margin-bottom: 24px; }
.frames { display: grid; gap: 20px; grid-template-columns: minmax(0, 1fr); align-items: start; }
@media (min-width: 600px) { .frames { grid-template-columns: repeat(2, minmax(0, 1fr)); } .f-t { grid-column: 1 / -1; } }

.frame { position: relative; background: var(--sheet); border: 1.5px solid var(--ink); padding: 22px 22px 24px; transition: opacity .5s; }
.frame::before { /* 제도 모서리 표식 */
  content: ""; position: absolute; inset: 5px; border: 1px solid var(--line); pointer-events: none; }
.f-head { display: flex; align-items: flex-start; gap: 14px; margin-bottom: 14px; }
.mark { flex: none; display: block; width: 56px; height: 56px; }
.mark svg { width: 100%; height: 100%; overflow: visible; }
.f-label { font: 600 14px/1.3 var(--mono); color: var(--ink-3); }
.f-title { font-size: 26px; line-height: 1.2; font-weight: 800; letter-spacing: -0.04em; margin-top: 2px; outline: none; }
.f-url { font: 500 14px/1.4 var(--mono); color: var(--ink-2); letter-spacing: 0; overflow-wrap: normal; word-break: keep-all; }
.steps { counter-reset: s; border-top: 1px solid var(--ink); }
.steps li { counter-increment: s; display: grid; grid-template-columns: 30px minmax(0, 1fr); gap: 0 0; padding: 10px 0; border-bottom: 1px solid var(--line); font-size: 15px; line-height: 1.55; }
.steps li::before { content: counter(s); grid-row: span 2; font: 700 14px/1.7 var(--mono); color: var(--red); }
.steps b { font-size: 16px; }
.steps span { color: var(--ink-2); }
.f-lead { color: var(--ink-2); margin-bottom: 14px; }
.parts { border-top: 1px solid var(--ink); }
.parts li { border-bottom: 1px solid var(--line); }
.parts a { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 2px 12px; padding: 12px 0; text-decoration: none; align-items: baseline; }
.parts b { font-size: 17px; font-weight: 700; letter-spacing: -0.02em; }
.parts .desc { grid-column: 1 / -1; font-size: 15px; color: var(--ink-2); line-height: 1.55; }
.parts .go { font: 700 17px/1 var(--font); color: var(--red); transition: transform .2s; }
.parts a:hover .go { transform: translate(2px, -2px); }
.parts a:hover b { text-decoration: underline; text-decoration-color: var(--red); text-underline-offset: 4px; }
.open { display: inline-flex; align-items: center; gap: 8px; min-height: 48px; margin-top: 16px; padding: 0 20px; background: var(--ink); color: var(--sheet); font-weight: 700; text-decoration: none; border: 0; }
.open:hover { background: var(--red); color: var(--on-red); }
.open svg { width: 18px; height: 18px; }
.notes { counter-reset: n; border-top: 1px solid var(--ink); }
.notes li { counter-increment: n; display: grid; grid-template-columns: 30px minmax(0, 1fr); padding: 10px 0; border-bottom: 1px solid var(--line); font-size: 15px; line-height: 1.6; }
.notes li::before { content: counter(n) "."; font: 600 14px/1.7 var(--mono); color: var(--ink-3); }
.tb { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1px; background: var(--ink); border: 1.5px solid var(--ink); }
.tb div { padding: 8px 10px; background: var(--sheet); min-width: 0; }
.tb .w { grid-column: 1 / -1; }
.tb dt { font: 500 14px/1.3 var(--mono); color: var(--ink-3); }
.tb dd { font-size: 16px; font-weight: 700; line-height: 1.45; }
.tb dd a { display: inline-flex; align-items: center; min-height: 44px; text-decoration-color: var(--red); text-underline-offset: 3px; }
.tb div { display: flex; flex-direction: column; justify-content: center; }
@media (min-width: 600px) { .tb { grid-template-columns: repeat(4, minmax(0, 1fr)); } .tb .w { grid-column: span 2; } }

/* 3-1. 확대 모드(스크립트가 켜질 때만) */
.stage.is-js { height: calc(100vh - var(--bar-h)); height: calc(100svh - var(--bar-h)); min-height: 520px; overflow: hidden; touch-action: pan-y; }
.stage.is-js .plane { position: absolute; left: 0; top: 0; margin: 0; padding: 0; transform-origin: 0 0; will-change: transform; transition: transform .95s cubic-bezier(.66, 0, .34, 1); }
.stage.is-js.no-anim .plane { transition: none; }
.stage.is-js .frame { cursor: zoom-in; }
.stage.is-js .frame.is-on { cursor: auto; }
.stage.is-js.is-zoomed .frame:not(.is-on) { opacity: .28; }
.stage.is-js .art-tall { margin: 0 0 24px; }
/* 좁은 화면: 760 너비 판, 위 그림 + 두 줄 칸 */
.stage.is-js .plane { width: 760px; padding: 32px 32px 40px; }
.stage.is-js .frames { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 28px; }
.stage.is-js .f-t { grid-column: 1 / -1; }
.stage.is-js .tb { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.stage.is-js .tb .w { grid-column: span 2; }
/* 넓은 화면: 1600×1100 조립도 판 */
@media (min-width: 900px) and (min-aspect-ratio: 1/1) {
  .stage.is-js .plane { width: 1600px; height: 1180px; padding: 0; }
  .stage.is-js .art-tall { display: none; }
  .stage.is-js .art-wide { display: block; position: absolute; inset: 0; width: 1600px; height: 1180px; }
  .stage.is-js .frames { display: block; }
  .stage.is-js .frame { position: absolute; width: 440px; }
  .stage.is-js .f-a { left: 60px; top: 280px; }
  .stage.is-js .f-n { left: 60px; top: 784px; }
  .stage.is-js .f-b { left: 1100px; top: 60px; }
  .stage.is-js .f-c { left: 1100px; top: 718px; }
  .stage.is-js .f-t { left: 560px; top: 872px; width: 500px; }
}

/* 3-2. 카메라 조작 줄 */
.cam { display: none; }
.stage.is-js .cam { display: flex; position: absolute; left: 50%; bottom: 16px; transform: translateX(-50%); z-index: 5; align-items: stretch; background: var(--sheet); border: 1.5px solid var(--ink); box-shadow: 4px 4px 0 var(--ink); white-space: nowrap; }
.cam button { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-width: 48px; min-height: 48px; padding: 0 14px; border: 0; background: transparent; color: var(--ink); font: 700 15px/1 var(--font); cursor: pointer; }
.cam button + button, .cam .where { border-left: 1px solid var(--ink); }
.cam button:hover { background: var(--red-tint); color: var(--red); }
.cam button[disabled] { color: var(--line-2); cursor: default; background: transparent; }
.cam svg { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.cam .where { display: inline-flex; align-items: center; gap: 8px; padding: 0 14px; font: 600 14px/1 var(--mono); min-width: 128px; justify-content: center; }
.cam .where b { color: var(--red); }
.cam .tour { background: var(--ink); color: var(--sheet); }
.cam .tour:hover { background: var(--red); color: var(--on-red); }
.stage:not(.is-zoomed) .cam .z-only { display: none; }
.stage.is-zoomed .cam .tour { display: none; }
.hint { display: none; }
@media (min-width: 900px) and (min-aspect-ratio: 1/1) { .stage.is-js:not(.is-zoomed) .hint { display: block; }}
.stage.is-js:not(.is-zoomed) .hint { position: absolute; top: 14px; left: var(--gutter); z-index: 5; font: 600 14px/1.3 var(--mono); color: var(--ink-2); background: var(--paper); padding: 4px 8px; border: 1px solid var(--line); }

/* 4. 본문 */
.section { padding: 64px 0; border-bottom: 1px solid var(--line); }
.section h2 { font-size: 28px; line-height: 1.3; font-weight: 800; letter-spacing: -0.04em; }
.section .num { font: 600 14px/1.4 var(--mono); color: var(--red); margin-bottom: 8px; }
.cols { display: grid; gap: 24px; margin-top: 24px; }
@media (min-width: 960px) {
  .section { padding: 96px 0; }
  .section h2 { font-size: 36px; }
  .split { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 8fr); column-gap: 48px; }
  .cols { grid-template-columns: repeat(2, minmax(0, 1fr)); column-gap: 48px; margin-top: 0; }
}
.prose p + p { margin-top: 14px; }
.prose p { color: var(--ink-2); }
.prose strong { color: var(--ink); }
.facts { border-top: 1.5px solid var(--ink); }
.facts div { display: grid; grid-template-columns: 7.5em minmax(0, 1fr); gap: 12px; padding: 12px 0; border-bottom: 1px solid var(--line); }
.facts dt { font: 500 14px/1.6 var(--mono); color: var(--ink-3); }
.facts dd { font-weight: 600; }

/* 5. 문서 페이지(소개·문의·처리방침) */
.doc { padding: 48px 0 96px; }
.doc .wrap > * { max-width: 46rem; }
.doc h1 { font-size: 32px; line-height: 1.25; font-weight: 800; letter-spacing: -0.04em; margin-top: 8px; }
.doc .lead { margin-top: 12px; color: var(--ink-2); }
.doc h2 { margin-top: 44px; padding-top: 16px; border-top: 1.5px solid var(--ink); font-size: 20px; font-weight: 800; letter-spacing: -0.03em; }
.doc h3 { margin-top: 20px; font-size: 17px; font-weight: 700; }
.doc p, .doc ul, .doc ol, .doc table, .doc dl { margin-top: 10px; }
.doc ul { list-style: disc; padding-left: 1.2em; }
.doc ol { list-style: decimal; padding-left: 1.4em; }
.doc li + li { margin-top: 4px; }
.doc a { color: var(--red); text-underline-offset: 3px; }
.doc .date { margin-top: 44px; font: 500 14px/1.6 var(--mono); color: var(--ink-3); }
.doc table { width: 100%; border-collapse: collapse; font-size: 15px; }
.doc th, .doc td { text-align: left; vertical-align: top; padding: 10px 8px; border-bottom: 1px solid var(--line); }
.doc th { font-weight: 700; border-bottom: 1.5px solid var(--ink); white-space: nowrap; }
.tablewrap { overflow-x: auto; }
.mailbox { margin-top: 20px; padding: 20px; border: 1.5px solid var(--ink); background: var(--sheet); }
.mailbox .mono { font-size: 14px; color: var(--ink-3); }
.mailbox a { font-size: 22px; font-weight: 800; letter-spacing: -0.02em; color: var(--ink); text-decoration-color: var(--red); }

/* 6. 바닥 */
.foot { padding: 40px 0 32px; font-size: 14px; color: var(--ink-2); background: var(--sheet); border-top: 1px solid var(--ink); }
.foot .wrap { display: grid; gap: 20px; }
.foot .logo { font-size: 17px; color: var(--ink); }
.foot ul { display: flex; flex-wrap: wrap; gap: 4px 18px; }
.foot a { display: inline-flex; min-height: 44px; align-items: center; }
.foot a:hover { color: var(--ink); }
.foot .biz { font-family: var(--mono); letter-spacing: 0; line-height: 1.7; }
@media (min-width: 960px) { .foot .wrap { grid-template-columns: minmax(0, 1fr) auto; align-items: start; } }

@media (prefers-reduced-motion: reduce) {
  .stage.is-js .plane, .frame { transition: none; }
}

/* 7. 조립도 그림 선 */
.art-wide, .art-tall { color: var(--ink); }
.ln { fill: none; stroke: var(--ink); stroke-width: 2; stroke-linejoin: round; }
.ln-th { fill: none; stroke: var(--ink); stroke-width: 1; }
.ln-hid { fill: none; stroke: var(--ink-3); stroke-width: 1.2; stroke-dasharray: 8 5; }
.ln-ctr { fill: none; stroke: var(--ink-3); stroke-width: 1; stroke-dasharray: 26 6 4 6; }
.ln-dim { fill: none; stroke: var(--ink-3); stroke-width: 1; }
.ln-red { fill: none; stroke: var(--red); stroke-width: 1.6; }
.ln-det { fill: none; stroke: var(--red); stroke-width: 1.6; stroke-dasharray: 12 6; }
.fill-sheet { fill: var(--sheet); }
.fill-hatch { fill: url(#hatch); }
.hatch-ln { stroke: var(--ink-3); stroke-width: 1; }
.t-big { font: 800 76px/1 var(--font); letter-spacing: -0.05em; fill: var(--ink); }
.t-mono { font: 600 18px/1 var(--mono); fill: var(--ink-2); }
.t-sm { font: 500 15px/1 var(--mono); fill: var(--ink-3); }
.t-zone { font: 500 14px/1 var(--mono); fill: var(--ink-3); text-anchor: middle; }
.t-lab { font: 700 26px/1 var(--mono); fill: var(--red); text-anchor: middle; dominant-baseline: central; }
.t-cell { font: 500 16px/1 var(--mono); fill: var(--ink-2); }
.t-cellb { font: 700 17px/1 var(--font); fill: var(--ink); }
.t-head { font: 600 14px/1 var(--mono); fill: var(--ink-3); }
.t-mid { text-anchor: middle; }

/* 8. 귀여운 요소: 마스코트 너티, 검수 도장, 청사진 인쇄선 */
.nutty-body { fill: var(--sheet); stroke: var(--ink); stroke-width: 3; stroke-linejoin: round; }
.nutty-ln { fill: none; stroke: var(--ink); stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; }
.nutty-eye { fill: var(--ink); }
.nutty-blush { fill: var(--red); opacity: .55; }
.nutty-hole { fill: none; stroke: var(--ink-3); stroke-width: 1.6; stroke-dasharray: 4 3; }
.nutty { animation: nutty-bob 2.6s ease-in-out infinite; transform-box: fill-box; transform-origin: 50% 100%; }
.nutty-arm { animation: nutty-wave 1.3s ease-in-out infinite; transform-box: fill-box; transform-origin: 0% 100%; }
@keyframes nutty-bob { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-5px); } }
@keyframes nutty-wave { 0%, 100% { transform: rotate(0deg); } 50% { transform: rotate(-22deg); } }
.bubble { fill: var(--sheet); stroke: var(--ink); stroke-width: 2; stroke-linejoin: round; }
.t-bubble { font: 700 17px/1 var(--font); fill: var(--ink); letter-spacing: -0.02em; text-anchor: middle; }
.stamp { opacity: .9; }
.stamp circle { fill: none; stroke: var(--red); }
.stamp text { fill: var(--red); text-anchor: middle; }
.stamp .s-big { font: 800 19px/1 var(--font); letter-spacing: -0.02em; }
.stamp .s-sm { font: 700 12px/1 var(--mono); letter-spacing: .08em; }
.stage::after { content: ""; position: absolute; left: 0; right: 0; top: 0; height: 140px; z-index: 4; pointer-events: none;
  background: linear-gradient(rgb(255 148 102 / 0), rgb(255 148 102 / .09)); border-bottom: 1.5px solid rgb(255 148 102 / .55);
  animation: print-scan 2.4s cubic-bezier(.4, 0, .2, 1) .25s both; }
@keyframes print-scan { 0% { transform: translateY(-140px); opacity: 1; } 85% { opacity: 1; } 100% { transform: translateY(calc(100svh)); opacity: 0; } }
.stage:not(.is-js)::after { display: none; }
.mark { transition: transform .25s; }
.frame:hover .mark { transform: rotate(-12deg) scale(1.06); }
@media (prefers-reduced-motion: reduce) {
  .nutty, .nutty-arm, .stage::after { animation: none; }
  .stage::after { display: none; }
}

/* 9. 손글씨 기호(A·B·C·N): 한 번에 휙 그린 동그라미 + 손글씨 글자 */
.hand { fill: none; stroke: var(--red); stroke-width: 2.6; stroke-linecap: round; stroke-linejoin: round; }
.hand-l { fill: none; stroke: var(--red); stroke-width: 3.4; stroke-linecap: round; stroke-linejoin: round; }

/* 10. 휴대폰(확대 무대 꺼짐): 카드를 제 크기로 한 줄씩 */
@media (max-width: 899px), (max-aspect-ratio: 1/1) {
  .stage .plane { width: 100%; max-width: 640px; padding: 20px var(--gutter) 40px; }
  .stage .art-tall { width: min(100%, 240px); margin: 0 auto 16px; }
  .stage .frame::before { display: none; }
  .stage .f-t { display: none; } /* 운영 정보는 바닥글에 이미 있다 */
  .stage .frames { grid-template-columns: minmax(0, 1fr); gap: 16px; }
  .stage .frame { padding: 20px 18px 22px; }
  .stage .f-title { font-size: 28px; }
  .stage .tb { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .stage .tb .w { grid-column: 1 / -1; }
}

/* 11. 그림 부품 누르기: 볼트(셈)·와셔(심)·너트(어명이오) */
.hot { cursor: pointer; }
.hot circle, .hot rect { fill: transparent; stroke: none; transition: fill .2s; }
.hot:hover circle, .hot:hover rect, .hot:focus-visible circle { fill: var(--red-tint); }
.frame { scroll-margin-top: calc(var(--bar-h) + 16px); }
.frame.is-ping { animation: ping 1.4s ease-out .35s 1; }
@keyframes ping { 0% { box-shadow: 0 0 0 0 rgb(255 148 102 / .7); border-color: var(--red); } 70% { box-shadow: 0 0 0 14px rgb(255 148 102 / 0); border-color: var(--red); } 100% { box-shadow: 0 0 0 0 rgb(255 148 102 / 0); } }
@media (prefers-reduced-motion: reduce) { .frame.is-ping { animation: none; outline: 2px solid var(--red); } }
/* 휴대폰: 기호 원이 살짝 숨쉬듯 — 누를 수 있다는 신호 */
@media (max-width: 899px), (max-aspect-ratio: 1/1) {
  .art-tall .hot circle:last-child { fill: rgb(255 148 102 / .14); animation: tap-hint 2.2s ease-in-out infinite; transform-box: fill-box; transform-origin: center; }
  @keyframes tap-hint { 0%, 100% { opacity: .2; } 50% { opacity: 1; } }
}
@media (prefers-reduced-motion: reduce) { .art-tall .hot circle:last-child { animation: none; } }