/*
  엄마 아빠가 내 나이였을 때(back-then) style.css v1 · 2026-11-01 · 심(boltandnutt.com)
  - 껍데기(내비·바닥글·버튼·메뉴·읽을거리)는 2027 첫 해(first-sun/style.css v1) 1~176줄과 같은 값, 색만 바꿈.
  - 고유 부분: 감열지 영수증 세 장. 바랜 종이, 먹색 글자, 그때 값은 고무도장 빨강 하나.
*/
:root {
  --bg: #ece7de; --surface: #fffdf8;
  --brand: #23506b; --brand-hover: #1c4258; --brand-press: #163546; --brand-tint: #e2ecf1; --on-brand: #ffffff;
  --ink: #1f1c18; --ink-2: #554e45; --line: #d6cdbf; --line-ui: #7d7468;
  --sp-1: 8px; --sp-2: 16px; --sp-3: 24px; --sp-4: 32px; --sp-5: 48px; --sp-6: 64px; --sp-7: 96px;
  --r-tag: 6px; --r-sm: 8px; --r-md: 12px;
  --f-display: 32px; --f-h3: 22px; --f-body: 16px; --f-sm: 15px; --f-min: 14px;
  --gutter: 16px; --nav-h: 56px;
  --paper: var(--bg); --paper-2: var(--bg); --ink-3: var(--ink-2); --rule-ui: var(--line-ui);
  --accent: var(--brand); --accent-ink: var(--on-brand); --focus: var(--brand);
  --font: "Pretendard", "Apple SD Gothic Neo", "Noto Sans KR", "Noto Sans CJK KR", "Malgun Gothic", system-ui, sans-serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16130f; --surface: #211d18; --brand: #8ec5df; --brand-hover: #a9d4e8; --brand-press: #c3e2f0;
    --brand-tint: #1b2d36; --on-brand: #0d1a20;
    --ink: #efe8dc; --ink-2: #bcb3a5; --line: #353029; --line-ui: #8a8174;
    --paper: var(--bg); --paper-2: var(--bg); --ink-3: var(--ink-2); --rule-ui: var(--line-ui);
    --accent: var(--brand); --accent-ink: var(--on-brand); --focus: var(--brand);
    color-scheme: dark;
  }
}
@media (min-width: 960px) {
  :root { --f-display: 56px; --f-h3: 28px; --gutter: 24px; --nav-h: 64px; }
}

body { background: var(--bg); color: var(--ink); font: 400 var(--f-body)/1.6 var(--font); letter-spacing: -0.01em; word-break: keep-all; overflow-wrap: anywhere; display: flex; flex-direction: column; min-height: 100vh; }
main { flex: 1; }
h1, h2, h3, p, ul { margin: 0; }
a:hover { color: inherit; }
.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: 20; padding: 8px 16px; background: var(--surface); border: 1.5px solid var(--brand); border-radius: var(--r-sm); }
:focus-visible { outline: 2px solid var(--brand); outline-offset: 2px; border-radius: 4px; }
.wrap { max-width: 1168px; margin: 0 auto; padding: 0 var(--gutter); }
.grid { display: grid; gap: var(--sp-2); grid-template-columns: minmax(0, 1fr); }
@media (min-width: 960px) {
  .grid { grid-template-columns: repeat(12, minmax(0, 1fr)); gap: var(--sp-3); }
  .c-12 { grid-column: span 12; } .c-7 { grid-column: span 7; } .c-5 { grid-column: span 5; } .c-4 { grid-column: span 4; }
}

/* 부품: 버튼(기본·올림·누름·비활성) · 태그 · 카드 · 원형 배지 — card-two-months/style.css 3절과 같은 값 */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: var(--sp-1); min-height: 48px; padding: 0 var(--sp-3); border-radius: var(--r-sm); border: 1.5px solid transparent; font: 700 var(--f-body)/1 var(--font); letter-spacing: -0.01em; text-decoration: none; cursor: pointer; transition: background-color .12s, border-color .12s, color .12s; filter: none; }
.btn:hover { filter: none; }
.btn-primary, .btn-primary:hover, .btn-primary:active { color: var(--on-brand); }
.btn-primary { background: var(--brand); }
.btn-primary:hover { background: var(--brand-hover); }
.btn-primary:active { background: var(--brand-press); }
.btn[aria-disabled="true"] { background: var(--line); color: var(--ink-2); cursor: not-allowed; }
.btn .ic { width: 18px; height: 18px; }
.ic { display: block; width: 20px; height: 20px; flex: none; }
.tag { display: inline-flex; align-items: center; gap: 4px; height: 26px; padding: 0 var(--sp-1); border-radius: var(--r-tag); font-size: var(--f-min); font-weight: 700; line-height: 1; white-space: nowrap; background: var(--brand-tint); color: var(--brand); }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r-md); padding: var(--sp-3); }
.badge { display: inline-grid; place-items: center; width: 48px; height: 48px; border-radius: 50%; background: var(--brand-tint); color: var(--brand); flex: none; }
.badge .ic { width: 24px; height: 24px; }

/* 상단 고정 내비게이션 */
.nav { position: sticky; top: 0; z-index: 10; background: var(--bg); border-bottom: 1px solid var(--line); }
@supports (background: color-mix(in srgb, #000 50%, transparent)) {
  .nav { background: color-mix(in srgb, var(--bg) 92%, transparent); -webkit-backdrop-filter: saturate(1.2) blur(8px); backdrop-filter: saturate(1.2) blur(8px); }
}
.nav .wrap { height: var(--nav-h); display: flex; align-items: center; gap: var(--sp-2); }
.logo { display: inline-flex; align-items: center; gap: var(--sp-1); text-decoration: none; font-size: 20px; font-weight: 800; letter-spacing: -0.04em; color: var(--ink); }
.logo svg { width: 28px; height: 28px; }
.nav-menu { margin-left: auto; display: flex; align-items: center; gap: var(--sp-1); }
.nav-menu a { font-size: var(--f-sm); font-weight: 600; color: var(--ink-2); text-decoration: none; padding: var(--sp-1) 12px; border-radius: var(--r-sm); }
.nav-menu a:hover { color: var(--ink); background: var(--surface); }

/* 모바일 상단 메뉴(T-0106): card-two-months/style.css 4-1절과 같은 규격. 959px 이하에서 [로고] … [메뉴] + 펼침 패널.
   첫 화면에는 카드 안 '카드 계산기 열기'가 대표 버튼이므로 줄에 행동 버튼을 따로 두지 않는다(같은 동작 버튼 중복 방지). */
[hidden] { display: none !important; }
.nav-toggle, .nav-panel { display: none; }
@media (max-width: 959px) {
  .nav-menu a { display: inline-flex; align-items: center; min-height: 44px; }
  .nav .logo { min-height: 44px; }
  .nav.is-js .nav-menu a:not(.btn) { display: none; }
  /* T-0128: 첫 화면 '주요 메뉴'의 유일 항목(계산기)이 위 규칙으로 숨으므로 nav 자체를 숨겨 빈 랜드마크를 없앤다.
     메뉴가 맡던 margin-left:auto 는 메뉴 버튼이 이어받아 버튼 위치는 그대로다. 960px 이상·스크립트 꺼짐은 영향 없음. */
  .nav.is-js .nav-menu { display: none; }
  .nav.is-js .nav-toggle { margin-left: auto; }
  .nav.is-js .wrap { gap: var(--sp-1); }
  .nav-toggle { display: inline-grid; place-items: center; flex: none; width: 44px; height: 44px; margin-right: -6px; padding: 0; border: 0; border-radius: var(--r-sm); background: transparent; color: var(--ink); cursor: pointer; transition: background-color .12s, color .12s; }
  .nav-toggle:hover { background: var(--surface); }
  .nav-toggle[aria-expanded="true"] { background: var(--brand-tint); color: var(--brand); }
  .nav-toggle svg { width: 24px; height: 24px; fill: none; stroke: currentColor; stroke-width: 1.75; stroke-linecap: round; }
  .nav-toggle .i-close, .nav-toggle[aria-expanded="true"] .i-open { display: none; }
  .nav-toggle[aria-expanded="true"] .i-close { display: block; }
  .nav.is-open { background: var(--bg); }
  .nav.is-open::after { content: ""; position: absolute; left: 0; right: 0; top: 100%; height: 100vh; background: rgb(17 20 18 / .32); z-index: -1; animation: nav-fade .16s ease-out both; }
  .nav-panel { display: block; position: absolute; left: 0; right: 0; top: 100%; background: var(--bg); border-bottom: 1px solid var(--line); max-height: calc(100vh - var(--nav-h)); max-height: calc(100dvh - var(--nav-h)); overflow-y: auto; overscroll-behavior: contain; animation: nav-in .16s cubic-bezier(.2, .7, .3, 1) both; }
  .nav .nav-panel .wrap { display: block; height: auto; padding-top: var(--sp-1); padding-bottom: var(--sp-3); }
  .np-label { display: flex; align-items: center; min-height: 44px; font-size: var(--f-min); font-weight: 600; color: var(--ink-2); text-decoration: none; }
  a.np-label:hover { color: var(--brand); text-decoration: underline; text-underline-offset: 3px; }
  .np-list, .np-sub { list-style: none; margin: 0; padding: 0; }
  .np-list > li { border-top: 1px solid var(--line); }
  .np-item { display: flex; align-items: center; justify-content: space-between; gap: var(--sp-2); min-height: 56px; font-size: 18px; font-weight: 700; letter-spacing: -0.02em; color: var(--ink); text-decoration: none; }
  .np-item .ic { color: var(--ink-2); fill: none; stroke: currentColor; stroke-width: 1.75; stroke-linecap: round; stroke-linejoin: round; }
  .np-item:hover, .np-item:hover .ic { color: var(--brand); }
  .np-sub { margin: -4px 0 var(--sp-2); display: grid; }
  .np-sub a { display: flex; align-items: center; min-height: 44px; padding-left: var(--sp-2); border-left: 2px solid var(--line); font-size: var(--f-sm); color: var(--ink-2); text-decoration: none; }
  .np-sub a:hover { color: var(--ink); border-left-color: var(--line-ui); }
}
@keyframes nav-in { from { opacity: 0; transform: translateY(-4px); } to { opacity: 1; transform: none; } }
@keyframes nav-fade { from { opacity: 0; } to { opacity: 1; } }
@media (prefers-color-scheme: dark) { .nav.is-open::after { background: rgb(0 0 0 / .55); } }

/* 푸터: card-two-months/style.css 11절과 같은 값 */
.foot { background: var(--surface); border-top: 1px solid var(--line); padding: var(--sp-5) 0 var(--sp-4); font-size: var(--f-min); color: var(--ink-2); line-height: 1.6; }
.foot .grid { row-gap: var(--sp-3); }
.foot-h { font-size: var(--f-min); font-weight: 700; color: var(--ink); margin: 0 0 var(--sp-1); }
.foot ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 4px; }
.foot .logo { font-size: 18px; margin-bottom: var(--sp-1); }
.foot .copy { margin-top: var(--sp-2); padding-top: var(--sp-2); border-top: 1px solid var(--line); }

@media (prefers-reduced-motion: reduce) {
  .svc, .svc:hover { transition: none; transform: none; }
  .nav-panel, .nav.is-open::after { animation: none; }
  .nav-toggle { transition: none; }
}

.nav-service { display: none; font-size: var(--f-sm); color: var(--ink-2); padding-left: var(--sp-2); border-left: 1px solid var(--line); }
@media (min-width: 960px) { .nav-service { display: inline; } }

.btn-line { background: var(--surface); border-color: var(--line-ui); color: var(--ink); }
.btn-line:hover { border-color: var(--ink); }
.sec-lead { margin-top: var(--sp-1); color: var(--ink-2); font-size: var(--f-sm); }
.sort { display: inline-flex; border: 1.5px solid var(--line-ui); border-radius: 999px; padding: 3px; }
.sort button { min-height: 38px; padding: 0 14px; border: 0; border-radius: 999px; background: none; color: var(--ink-2); font: 700 var(--f-min)/1 var(--font); cursor: pointer; }
.sort button[aria-pressed="true"] { background: var(--ink); color: var(--bg); }
/* 읽을거리 */
.guides { padding: var(--sp-4) 0 var(--sp-6); }
.guide-list { list-style: none; margin: var(--sp-3) 0 0; padding: 0; display: grid; gap: 0; }
.guide-list a { display: grid; gap: 4px; padding: var(--sp-2) 0; border-top: 1px solid var(--line); text-decoration: none; }
.guide-list li:last-child a { border-bottom: 1px solid var(--line); }
.guide-list b { font-size: 18px; letter-spacing: -0.02em; }
.guide-list span { font-size: var(--f-sm); color: var(--ink-2); }
.guide-list a:hover b { color: var(--brand); text-decoration: underline; text-underline-offset: 3px; }
.series { padding: 0 0 var(--sp-4); }
.series a { display: flex; align-items: center; justify-content: space-between; gap: var(--sp-2); padding: var(--sp-3); border-radius: var(--r-md); background: var(--sea); color: var(--chart-ink); text-decoration: none; }
.series b { display: block; font-size: 20px; letter-spacing: -0.03em; }
.series span { font-size: var(--f-sm); color: var(--chart-ink-2); }
.series .ic { width: 24px; height: 24px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.series a:hover b { text-decoration: underline; text-underline-offset: 4px; }

.doc-table th { white-space: nowrap; }
.doc-table.is-wide { min-width: 540px; }
/* 쿠팡 파트너스 상품 구역(2026-10-26 개편): 사진 + 이름 + 한 줄, 가격은 쓰지 않는다(바뀌므로) */
.shop .shop-head { display: flex; align-items: center; gap: 8px; }
.shop .shop-head h2, .shop .shop-head h3 { margin: 0; }
.shop-tag { flex: none; font-size: 14px; line-height: 1; padding: 5px 7px; border: 1px solid var(--line); border-radius: 4px; color: var(--ink-2); }
.shop-lead { margin: 6px 0 0; color: var(--ink-2); font-size: var(--f-sm, 15px); }
.shop-list { list-style: none; margin: 16px 0 0; padding: 0; display: grid; gap: 10px; }
.shop-item { display: grid; grid-template-columns: 72px minmax(0, 1fr) 20px; align-items: center; gap: 14px; padding: 10px 12px 10px 10px; border: 1px solid var(--line); border-radius: 12px; background: var(--surface, var(--bg, #fff)); color: var(--ink); text-decoration: none; transition: border-color .15s ease; }
.shop-item:hover { border-color: var(--ink-2); }
.shop-item:focus-visible { outline: 2px solid var(--brand); outline-offset: 2px; }
.shop-img { width: 72px; height: 72px; border-radius: 8px; background: #fff; overflow: hidden; display: grid; place-items: center; }
.shop-img img { width: 100%; height: 100%; object-fit: contain; display: block; }
.shop-txt { display: grid; gap: 2px; min-width: 0; }
.shop-txt b { font-size: 16px; line-height: 1.35; letter-spacing: -0.01em; }
.shop-txt span { font-size: 14px; line-height: 1.45; color: var(--ink-2); }
.shop-go { width: 18px; height: 18px; fill: none; stroke: var(--ink-2); stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.shop-item:hover .shop-go { stroke: var(--brand); }
.shop-note { margin: 12px 0 0; color: var(--ink-2); font-size: 14px; line-height: 1.5; }
@media (min-width: 720px) {
  .shop-list { grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); }
  .shop-item { grid-template-columns: 88px minmax(0, 1fr) 20px; }
  .shop-img { width: 88px; height: 88px; }
}
.shop { padding-bottom: var(--sp-4, 32px); }



/* ───────── 그때 그 값 고유 부분 ───────── */
:root { --stamp: #b0472f; --paper: #fffdf8; --mono: "SF Mono", "Menlo", "Consolas", "D2Coding", "Noto Sans Mono CJK KR", ui-monospace, monospace; }
@media (prefers-color-scheme: dark) { :root { --stamp: #e6866e; --paper: #221e19; } }
.btn-primary { background: var(--ink); }
.btn-primary:hover { background: var(--ink-2); }
.btn-primary:active { background: var(--ink); }
.btn-primary, .btn-primary:hover, .btn-primary:active { color: var(--bg); }
.num { font-variant-numeric: tabular-nums; }

.hero { padding: var(--sp-4) 0 var(--sp-2); }
.kicker { font-size: var(--f-sm); font-weight: 700; color: var(--ink-2); }
.kicker a { color: inherit; }
.hero h1 { margin-top: var(--sp-1); font-size: clamp(30px, 7.4vw, 56px); line-height: 1.14; font-weight: 800; letter-spacing: -0.05em; }
.hero-sub { margin-top: var(--sp-2); font-size: 17px; line-height: 1.6; color: var(--ink-2); max-width: 30em; }
@media (min-width: 960px) { .hero { padding: var(--sp-6) 0 var(--sp-3); } }

.calc { padding: var(--sp-2) 0 var(--sp-4); }
.pick { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px var(--sp-2); max-width: 640px; }
.pick-f label { display: block; font-size: var(--f-sm); font-weight: 700; color: var(--ink-2); margin-bottom: 4px; }
.pick select { width: 100%; min-height: 52px; padding: 0 30px 0 8px; border: 0; border-bottom: 2px solid var(--ink); border-radius: 0; background: transparent url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M6 9l6 6 6-6' fill='none' stroke='%237d7468' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") no-repeat right 4px center / 18px; color: var(--ink); font: 700 18px/1.2 var(--font); -webkit-appearance: none; appearance: none; cursor: pointer; }
.pick select:focus-visible { outline: 2px solid var(--brand); outline-offset: 2px; }
.pick option { color: #1f1c18; background: #fffdf8; }
.pick-note { margin-top: var(--sp-1); font-size: var(--f-min); color: var(--ink-2); min-height: 1.4em; }
.out { margin-top: var(--sp-3); }
.lead { font-size: 17px; font-weight: 700; line-height: 1.55; max-width: 36em; }

/* 영수증 세 장 */
.receipts { margin-top: var(--sp-3); display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--sp-3); }
.rc { position: relative; background: var(--paper); padding: 22px 18px 30px; box-shadow: 0 1px 2px rgb(0 0 0 / .06);
  -webkit-mask: conic-gradient(from -45deg at bottom, #0000, #000 1deg 89deg, #0000 90deg) 50% / 16px 100%;
          mask: conic-gradient(from -45deg at bottom, #0000, #000 1deg 89deg, #0000 90deg) 50% / 16px 100%; }
.rc-h { display: flex; justify-content: space-between; align-items: baseline; gap: 8px; padding-bottom: 12px; border-bottom: 2px dashed var(--ink); }
.rc-who { font-size: 17px; font-weight: 800; letter-spacing: -0.02em; }
.rc-yr { font: 800 28px/1 var(--mono); letter-spacing: -0.02em; }
.rc-then .rc-yr { color: var(--stamp); border: 2.5px solid var(--stamp); border-radius: 6px; padding: 4px 8px 3px; transform: rotate(-4deg); }
.rc-list { margin: 0; }
.rc-row { display: flex; justify-content: space-between; align-items: baseline; gap: 10px; padding: 8px 0; border-bottom: 1px dotted var(--line); }
.rc-row dt { font-size: var(--f-min); color: var(--ink-2); }
.rc-row dd { margin: 0; text-align: right; font: 700 16px/1.3 var(--mono); font-variant-numeric: tabular-nums; }
.rc-row small { display: block; font: 600 14px/1.4 var(--font); color: var(--ink-2); }
.rc-then .rc-row dd { color: var(--stamp); }
.rc-cut { height: 0; margin: 10px 0 2px; border-top: 2px dashed var(--line-ui); }
@media (min-width: 900px) {
  .receipts { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--sp-3); }
  .rc-now { transform: translateY(18px); }
}
.notes { list-style: none; margin: var(--sp-4) 0 0; padding: 0; max-width: 40em; border-top: 2px solid var(--ink); }
.notes li { padding: 12px 0; border-bottom: 1px solid var(--line); font-size: 17px; line-height: 1.6; }
.notes b { color: var(--stamp); }
.share { display: flex; flex-wrap: wrap; align-items: center; gap: var(--sp-1) var(--sp-2); margin-top: var(--sp-3); }
.share-note { flex-basis: 100%; font-size: var(--f-min); color: var(--ink-2); min-height: 1.4em; }

.years { padding: var(--sp-4) 0; border-top: 1px solid var(--line); }
.years h2, .faq h2, .guides h2 { font-size: var(--f-h3); font-weight: 800; letter-spacing: -0.035em; line-height: 1.25; }
.sec-lead { margin-top: var(--sp-1); font-size: var(--f-sm); line-height: 1.6; color: var(--ink-2); max-width: 40em; }
.tbl-wrap { overflow-x: auto; }
.tbl { width: 100%; max-width: 680px; margin-top: var(--sp-2); border-collapse: collapse; font-size: var(--f-sm); }
.tbl th, .tbl td { padding: 10px 8px 10px 0; border-bottom: 1px solid var(--line); text-align: left; }
.tbl thead th { font-size: var(--f-min); color: var(--ink-2); border-bottom: 2px solid var(--ink); }
.tbl .num { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
.tbl tbody th { font-weight: 700; }

.faq { padding: var(--sp-4) 0; border-top: 1px solid var(--line); }
.faq .wrap > h2 { margin-bottom: var(--sp-2); }
.faq details { border-bottom: 1px solid var(--line); max-width: 760px; }
.faq summary { display: flex; align-items: center; justify-content: space-between; gap: var(--sp-2); min-height: 56px; font-size: 17px; font-weight: 700; cursor: pointer; list-style: none; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font: 400 24px/1 var(--font); color: var(--ink-2); }
.faq details[open] summary::after { content: "−"; }
.faq details p { padding: 0 0 var(--sp-2); font-size: 16px; line-height: 1.7; color: var(--ink-2); }

.article { padding: var(--sp-4) 0 var(--sp-6); }
.article .wrap { max-width: 760px; }
.article h1 { margin-top: var(--sp-1); font-size: clamp(28px, 6vw, 44px); line-height: 1.2; font-weight: 800; letter-spacing: -0.045em; }
.article .lede { margin-top: var(--sp-2); font-size: 18px; line-height: 1.65; color: var(--ink-2); }
.article h2 { margin: var(--sp-5) 0 var(--sp-2); font-size: 22px; font-weight: 800; letter-spacing: -0.03em; }
.article p { font-size: 17px; line-height: 1.75; }
.article p + p { margin-top: var(--sp-2); }
.article .back { margin-top: var(--sp-5); }
@media (max-width: 479px) { .pick select { font-size: 16px; } }