/* 111 白銀板金工業 — K04 カードが重なっていく（sticky・CSSだけ）。形は「スマホのまま横に延長」：
   PCでも1列。写真と色の帯は画面の端まで、文字の列だけ最大 680px。
   色と書体は共通の13変数だけ。暗い面は .t-dark が同じ名前の変数を上書きする */
:root {
  --c-bg: #f5f5f4;
  --c-bg-alt: #ffffff;
  --c-text: #374151;
  --c-sub: #4b5563;
  --c-line: #c9ccd1;
  --c-accent: #3f4246;
  --c-accent-text: #3f4246;
  --c-on-accent: #ffffff;
  --c-2: #a9acb1;
  --c-3: #111214;
  --font-ja: "Noto Sans JP", sans-serif;
  --font-head: "BIZ UDPMincho", "Noto Sans JP", serif;
  --font-en: "Syncopate", "Noto Sans JP", sans-serif;
  --header-h: 60px;
  --card-h: calc(100svh - var(--header-h));
  --shadow: 0 -14px 34px color-mix(in srgb, black 16%, transparent);
}
.t-dark { --c-bg: #1a1b1d; --c-bg-alt: #232427; --c-text: #ecedee; --c-sub: #b9bcc1; --c-line: #4a4d52; --c-accent: #c9ccd1; --c-accent-text: #c9ccd1; --c-on-accent: #111214; --c-3: #ffffff; }

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: var(--header-h); -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--c-bg); color: var(--c-text); font-family: var(--font-ja); font-weight: 300; font-size: 16px; line-height: 2; overflow-x: hidden; }
figure { margin: 0; }
img { display: block; max-width: 100%; height: auto; }
h1, h2, h3, p, dd, li { word-break: auto-phrase; overflow-wrap: anywhere; }
h1, h2, h3, p, dl, dd, ol, ul { margin: 0; }
ul, ol { padding: 0; list-style: none; }

/* ===== ヘッダー ===== */
.header { position: sticky; top: 0; z-index: 50; height: var(--header-h); background: var(--c-bg); border-bottom: 1px solid var(--c-line); }
.header__inner { height: 100%; padding: 0 20px; display: flex; align-items: center; gap: 10px; position: relative; }
.logo { display: flex; flex-direction: column; text-decoration: none; color: var(--c-3); white-space: nowrap; flex: none; min-height: 44px; justify-content: center; margin-right: auto; }
.logo__ja { font-family: var(--font-head); font-weight: 700; font-size: 17px; line-height: 1.3; }
.logo__en { font-family: var(--font-en); font-size: 15px; letter-spacing: .3em; line-height: 1.2; color: var(--c-accent-text); }
.btn { display: inline-flex; align-items: center; justify-content: center; min-height: 52px; padding: 0 28px; background: var(--c-accent); color: var(--c-on-accent); font-family: var(--font-ja); font-weight: 500; font-size: 16px; text-decoration: none; white-space: nowrap; flex: none; border: 0; cursor: pointer; letter-spacing: .06em; }
.btn--sm { min-height: 44px; padding: 0 18px; }
.spmenu summary { list-style: none; cursor: pointer; display: flex; align-items: center; justify-content: center; min-width: 44px; min-height: 44px; color: var(--c-3); }
.spmenu summary::-webkit-details-marker { display: none; }
.spmenu__label { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.spmenu__bar, .spmenu__bar::before, .spmenu__bar::after { display: block; width: 22px; height: 1px; background: currentColor; position: relative; }
.spmenu__bar::before, .spmenu__bar::after { content: ""; position: absolute; left: 0; }
.spmenu__bar::before { top: -7px; } .spmenu__bar::after { top: 7px; }
.spmenu[open] .spmenu__bar { background: transparent; }
.spmenu[open] .spmenu__bar::before { top: 0; transform: rotate(45deg); }
.spmenu[open] .spmenu__bar::after { top: 0; transform: rotate(-45deg); }
.spmenu__nav { position: absolute; right: 0; top: 100%; width: min(100%, 360px); background: var(--c-bg); border: 1px solid var(--c-line); padding: 6px 24px 14px; display: flex; flex-direction: column; }
.spmenu__nav a { display: flex; align-items: center; min-height: 52px; color: var(--c-text); text-decoration: none; border-bottom: 1px solid var(--c-line); }

/* ===== K04：重なるカード ===== */
.stack { position: relative; }
.card { position: sticky; top: var(--header-h); min-height: var(--card-h); background: var(--c-bg); color: var(--c-text); border-radius: 22px 22px 0 0; box-shadow: var(--shadow); padding: 0 0 48px; display: flex; flex-direction: column; justify-content: center; overflow: hidden; }
.card:first-child { border-radius: 0; box-shadow: none; }
.card--about, .card--process { justify-content: flex-start; }
.card--about, .card--works { background: var(--c-bg-alt); }
.col { position: relative; z-index: 1; width: 100%; max-width: 680px; margin: 0 auto; padding: 0 20px; }
.col--wide { max-width: 1200px; }
.en { font-family: var(--font-en); font-weight: 400; font-size: 15px; letter-spacing: .28em; color: var(--c-accent-text); line-height: 1.6; margin-bottom: 12px; }
.h2 { font-family: var(--font-head); font-weight: 700; font-size: clamp(26px, 6.6vw, 38px); line-height: 1.5; color: var(--c-3); margin-bottom: 14px; }
.band { margin: 0 0 24px; width: 100%; height: clamp(140px, 26svh, 340px); overflow: hidden; }
.band img { width: 100%; height: 100%; object-fit: cover; }
.band--weld img { object-position: 50% 62%; }
.band--bend img { object-position: 50% 45%; }

/* --- 1 メインビジュアル --- */
.card--hero { padding: 40px 0 48px; }
.fold { position: absolute; right: -6%; bottom: 6%; width: min(70vw, 760px); height: auto; fill: none; stroke: var(--c-line); stroke-width: 1.2; pointer-events: none; }
.hero__en { margin-bottom: 18px; }
.hero__title { font-family: var(--font-head); font-weight: 700; font-size: clamp(64px, min(21vw, 24svh), 230px); line-height: 1.12; letter-spacing: .02em; color: var(--c-3); margin-bottom: 20px; }
.hero__lead { max-width: 560px; margin-bottom: 26px; }
.stamp { position: absolute; right: 16px; bottom: 20px; width: 150px; height: 150px; z-index: 2; color: var(--c-accent-text); }
.stamp svg, .ring svg { width: 100%; height: 100%; }
.stamp text, .ring text { font-family: var(--font-en); font-size: 21px; fill: currentColor; }
@media (prefers-reduced-motion: no-preference) {
  .stamp svg, .ring svg { animation: spin 40s linear infinite; }
  /* E03：見出しが1文字ずつ、ぼかし＋透明から現れる（JSが is-motion を付けたときだけ・1回） */
  .is-motion .ch { display: inline-block; animation: chIn 1.1s cubic-bezier(.2, .7, .2, 1) both; animation-delay: calc(var(--i) * 110ms + 150ms); }
}
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes chIn { from { opacity: 0; filter: blur(14px); } to { opacity: 1; filter: blur(0); } }

/* --- 3 工程 --- */
.steps { border-top: 1px solid var(--c-line); margin-top: 16px; }
.steps li { display: grid; grid-template-columns: 44px 5.5em 1fr; gap: 6px 10px; align-items: baseline; padding: 11px 0; border-bottom: 1px solid var(--c-line); line-height: 1.7; }
.steps__no { font-family: var(--font-en); font-size: 15px; letter-spacing: .1em; color: var(--c-accent-text); }
.steps b { font-family: var(--font-head); font-size: 19px; color: var(--c-3); }

/* --- 4 製作事例 --- */
.card--works { padding-bottom: 36px; }
.slider { margin-top: 8px; }
.slider__viewport { overflow-x: auto; scroll-snap-type: x mandatory; scroll-padding-inline: 20px; padding: 0 20px 14px; }
.slider__track { display: flex; gap: 16px; width: max-content; }
.slider__item { width: 74vw; max-width: 360px; flex: none; scroll-snap-align: start; }
.slider.is-swiper .slider__viewport { overflow: hidden; scroll-snap-type: none; }
.slider.is-swiper .slider__track { gap: 0; width: auto; }
.slider.is-swiper .slider__item { width: auto; max-width: none; }
.work { border: 1px solid var(--c-line); background: var(--c-bg); }
.work__img { aspect-ratio: 4 / 3; overflow: hidden; background: var(--c-bg); }
.work__img img { width: 100%; height: 100%; object-fit: cover; }
.work__img--item { background: var(--c-bg-alt); }
.work__img--item img { object-fit: contain; padding: 8px; }
.work__img--zoom img { object-fit: cover; object-position: 8% 60%; padding: 0; transform: scale(1.6); transform-origin: 20% 62%; }
.work__body { padding: 12px 18px 18px; }
.work__tag { font-family: var(--font-en); font-size: 15px; letter-spacing: .08em; color: var(--c-accent-text); line-height: 1.6; }
.work h3 { font-family: var(--font-head); font-size: 19px; line-height: 1.5; color: var(--c-3); margin: 0 0 2px; }
.work p:last-child { font-size: 15px; line-height: 1.8; color: var(--c-sub); }
.slider__ctrl { display: flex; align-items: center; justify-content: center; gap: 10px; margin-top: 8px; }
.slider__ctrl[hidden] { display: none; }
.slider__arrow { width: 48px; height: 48px; border: 1px solid var(--c-accent); background: transparent; position: relative; cursor: pointer; }
.slider__arrow::before { content: ""; position: absolute; left: 50%; top: 50%; width: 10px; height: 10px; border-top: 1px solid var(--c-accent-text); border-right: 1px solid var(--c-accent-text); transform: translate(-65%, -50%) rotate(45deg); }
.slider__prev::before { transform: translate(-35%, -50%) rotate(-135deg); }
.slider__dots, .slider__dots.swiper-pagination-horizontal { position: static; width: auto; transform: none; display: flex; }
.slider__dots .swiper-pagination-bullet { width: 30px; height: 44px; margin: 0 !important; background: transparent; opacity: 1; position: relative; border-radius: 0; }
.slider__dots .swiper-pagination-bullet::before { content: ""; position: absolute; left: 7px; top: 21px; width: 16px; height: 2px; background: var(--c-line); }
.slider__dots .swiper-pagination-bullet-active::before { background: var(--c-accent); }

/* --- 5 数字と設備 --- */
.nums { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; border-top: 1px solid var(--c-line); border-bottom: 1px solid var(--c-line); padding: 14px 0; margin: 10px 0 18px; }
.nums dt { font-size: 15px; color: var(--c-sub); line-height: 1.5; }
.nums dd { font-size: 15px; line-height: 1.4; }
.nums b { font-family: var(--font-head); font-weight: 700; font-size: clamp(24px, 6.6vw, 34px); color: var(--c-3); }
.spec { width: 100%; border-collapse: collapse; }
.spec th, .spec td { text-align: left; padding: 9px 0; border-bottom: 1px solid var(--c-line); font-weight: 400; font-size: 16px; line-height: 1.6; }
.spec th { width: 9.5em; color: var(--c-sub); }

/* --- 6 相談 --- */
.card--contact { padding-bottom: 56px; }
.ring__text { letter-spacing: .3em; }
.ring { position: relative; width: 210px; height: 210px; margin: 22px 0 14px; color: var(--c-accent-text); }
.ring__btn { position: absolute; inset: 44px; display: grid; place-items: center; border-radius: 50%; background: var(--c-accent); color: var(--c-on-accent); font-weight: 500; font-size: 16px; text-decoration: none; text-align: center; line-height: 1.3; }
.tel { font-family: var(--font-head); font-weight: 700; font-size: 18px; color: var(--c-3); }
.addr { font-size: 15px; color: var(--c-sub); }

/* ===== フッター ===== */
.footer { position: relative; z-index: 2; padding: 32px 20px 40px; text-align: center; background: var(--c-3); color: var(--c-bg-alt); font-size: 15px; line-height: 1.9; }
.footer__logo { font-family: var(--font-head); font-size: 17px; }
.footer__fiction { color: var(--c-line); }

@media (min-width: 768px) {
  .header__inner { padding: 0 40px; }
  .col { padding: 0 32px; }
  .band { height: clamp(180px, 30svh, 380px); }
  .stamp { width: 180px; height: 180px; right: 40px; bottom: 36px; }
  .slider__viewport { padding: 0 40px 14px; scroll-padding-inline: 40px; }
  .slider__item { width: 340px; }
  .steps li { grid-template-columns: 56px 6em 1fr; }
}
@media (min-width: 1080px) {
  .hero__lead { font-size: 17px; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }