/* immutable Studio — 黒い芯と、控えめな虹色の螺旋 */
:root {
  --ink: #050505;
  --paper: #ffffff;
  --tint: #f5f5f3;
  --muted: #5c5c5c;
  --line: #e2e2df;
  --iris: linear-gradient(90deg, #7346ef, #3e7ef9 22%, #0bcbcc 40%, #a2dd5f 55%, #ffdf40 70%, #fe9145 85%, #ff6b65);
  /* ロゴの文字と同じ Helvetica Neue Medium。入っていない端末では形の近い Arimo で表示する */
  --latin: "Helvetica Neue", Helvetica, Arimo, Arial, sans-serif;
  --jp: "Helvetica Neue", Arimo, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic UI", "Yu Gothic", Meiryo, sans-serif;
  --wrap: 1120px;
  --gutter: clamp(16px, 5vw, 48px);
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--jp);
  font-size: 16px;
  line-height: 1.9;
  letter-spacing: .02em;
  font-feature-settings: "palt";
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; }
h1, h2, h3, p, ol, ul, dl, dd, figure { margin: 0; }
ol, ul { padding: 0; list-style: none; }

.wrap { width: 100%; max-width: calc(var(--wrap) + var(--gutter) * 2); margin: 0 auto; padding: 0 var(--gutter); }

/* ロゴの文字と同じく、字間0.14em・縦80％の英字 */
.label, .service-no, .step-node, .variables .word, .nav-sub {
  font-family: var(--latin);
  font-weight: 500;
  letter-spacing: .14em;
}
.label {
  display: inline-block;
  font-size: 13px;
  text-transform: lowercase;
  transform: scaleY(.8);
  transform-origin: left center;
  color: var(--muted);
}
.label::before {
  content: ""; display: inline-block; width: 18px; height: 2px; margin-right: 10px;
  vertical-align: middle; background: var(--iris); border-radius: 1px;
}

/* ヘッダー */
.site-header {
  position: sticky; top: 0; z-index: 10;
  background: rgba(255, 255, 255, .86);
  backdrop-filter: saturate(1.4) blur(12px);
  -webkit-backdrop-filter: saturate(1.4) blur(12px);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; gap: 24px; }
.brand img { width: 168px; }
.nav { display: flex; align-items: center; gap: clamp(14px, 2.4vw, 30px); font-size: 13px; }
.nav a { text-decoration: none; }
.nav-sub { position: relative; display: inline-block; color: var(--muted); transform: scaleY(.8); transition: color .2s; }
.nav-sub::after {
  content: ""; position: absolute; left: 0; right: .14em; bottom: -3px; height: 2px;
  background: var(--iris); transform: scaleX(0); transform-origin: left; transition: transform .35s ease;
}
.nav-sub:hover { color: var(--ink); }
.nav-sub:hover::after { transform: scaleX(1); }
.nav-cta { padding: 6px 16px; border: 1px solid var(--ink); border-radius: 999px; font-size: 13px; transition: background .2s, color .2s; }
.nav-cta:hover { background: var(--ink); color: var(--paper); }

/* ファーストビュー */
.hero { position: relative; padding: clamp(48px, 8vw, 104px) 0 0; overflow: hidden; }
.hero-inner { position: relative; display: grid; grid-template-columns: 1.1fr .9fr; align-items: center; gap: clamp(32px, 6vw, 80px); }
.hero-copy .label { margin-bottom: 20px; }
.hero h1 { font-size: clamp(40px, 6.4vw, 76px); font-weight: 600; line-height: 1.25; letter-spacing: .03em; }
.hero-sub { margin-top: 20px; font-size: clamp(17px, 2vw, 22px); font-weight: 600; letter-spacing: .06em; }
.iris-text { background: var(--iris); -webkit-background-clip: text; background-clip: text; color: transparent; }
.lead { max-width: 30em; margin-top: 28px; color: #2b2b2b; }
.button {
  display: inline-flex; align-items: center; gap: 12px; margin-top: 36px;
  padding: 14px 28px; background: var(--ink); color: var(--paper);
  border-radius: 999px; text-decoration: none; font-size: 15px; transition: box-shadow .3s;
}
.button::after { content: "→"; transition: transform .2s; }
.button:hover { box-shadow: 0 10px 30px -12px rgba(83, 89, 238, .6); }
.button:hover::after { transform: translateX(4px); }

.hero-mark { position: relative; justify-self: center; width: min(100%, 440px); aspect-ratio: 1; display: grid; place-items: center; }
.hero-mark img { position: relative; width: 82%; }
.hero-mark::before {
  content: ""; position: absolute; inset: 14%;
  background: radial-gradient(closest-side, rgba(62, 126, 249, .14), rgba(245, 236, 59, .07) 60%, transparent);
  filter: blur(20px);
}
/* Mのまわりをめぐる、真上から見た螺旋の軌道 */
.orbit { position: absolute; inset: 0; border-radius: 50%; border: 1px solid var(--line); animation: orbit 18s linear infinite; }
.orbit-2 { inset: 9%; border-style: dashed; border-color: #d6d6d2; animation-duration: 26s; animation-direction: reverse; }
.orbit::after {
  content: ""; position: absolute; top: -5px; left: calc(50% - 5px); width: 10px; height: 10px;
  border-radius: 50%; background: #7346ef;
}
.orbit-2::after { background: #fe9145; }
@keyframes orbit { to { transform: rotate(1turn); } }

.hero-helix { margin-top: clamp(48px, 7vw, 88px); }
.helix-band { display: block; width: 100%; height: auto; overflow: visible; }
.helix-band g > * { animation: 1.6s ease-in-out infinite alternate; animation-delay: var(--d); }
.helix-band .rung { stroke-width: 1.5; stroke-opacity: .28; animation-name: squash; }
.helix-band .s1 { animation-name: rise; }
.helix-band .s2 { animation-name: fall; }
@keyframes rise { from { transform: translateY(calc(var(--amp) * -1)); } to { transform: translateY(var(--amp)); } }
@keyframes fall { from { transform: translateY(var(--amp)); } to { transform: translateY(calc(var(--amp) * -1)); } }
@keyframes squash { from { transform: scaleY(1); } to { transform: scaleY(-1); } }

/* 時代の変数（流れる帯） */
.variables { display: flex; align-items: stretch; background: var(--ink); color: var(--paper); overflow: hidden; }
.variables-label {
  flex: none; display: flex; align-items: center; padding: 0 clamp(16px, 3vw, 32px);
  font-family: var(--latin); font-weight: 500; font-size: 13px; letter-spacing: .14em;
  color: #a8a8a8; border-right: 1px solid #222; background: var(--ink); z-index: 1;
}
.variables-label span { display: inline-block; transform: scaleY(.8); }
.marquee { flex: 1; overflow: hidden; padding: 20px 0; mask-image: linear-gradient(90deg, transparent, #000 6%, #000 94%, transparent); }
.marquee-track { display: flex; align-items: center; width: max-content; animation: marquee 40s linear infinite; }
.variables .word { display: inline-block; padding: 0 22px; font-size: clamp(20px, 2.6vw, 30px); transform: scaleY(.8); white-space: nowrap; }
.variables .dot { flex: none; width: 6px; height: 6px; border-radius: 50%; background: var(--iris); }
@keyframes marquee { to { transform: translateX(-50%); } }

/* セクション共通 */
.section { padding: clamp(80px, 11vw, 140px) 0; }
.section-tint { background: var(--tint); }
.section-head { margin-bottom: clamp(36px, 5vw, 60px); }
.section-head .label { margin-bottom: 10px; }
.section h2 { font-size: clamp(26px, 3.4vw, 38px); font-weight: 600; letter-spacing: .05em; line-height: 1.45; }

/* 変わらないもの（考え方） */
.philo-grid { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(32px, 6vw, 72px); align-items: start; }
.philo-text { display: grid; gap: 1.3em; font-size: 16px; }
.philo-text p:first-child { font-size: clamp(18px, 1.9vw, 21px); font-weight: 600; line-height: 1.8; }
.views { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.view { padding: 20px 18px 22px; border: 1px solid var(--line); border-radius: 8px; background: var(--paper); }
.view figcaption { margin-top: 12px; font-size: 13px; line-height: 1.75; color: #444; }
.view figcaption strong { display: block; margin-bottom: 4px; font-size: 14px; color: var(--ink); }
.diagram { width: 100%; height: auto; display: block; }
.diagram .guide { fill: none; stroke: var(--line); stroke-dasharray: 2 5; }
.diagram .ring { fill: none; stroke: #cfcfe6; stroke-width: 1; }
.diagram .marker { fill: var(--ink); }
.diagram .core { font: 600 18px var(--jp); fill: var(--ink); letter-spacing: .1em; }
.diagram .axis { stroke: #d0d0cc; stroke-dasharray: 3 4; }
.diagram .coil-back { fill: none; stroke: #c9c9d6; stroke-width: 1.4; }
.diagram .coil-front { fill: none; stroke-width: 3.2; stroke-linecap: round; }
.diagram .leader { stroke: #bdbdbd; stroke-dasharray: 2 3; }
.diagram .era { font: 600 13px var(--jp); fill: var(--ink); }

/* 事業内容 */
.section-lead { margin-top: 14px; color: #333; }
/* 事業の目次：押すとその事業の段へ移る */
.service-index { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 32px; }
.service-index a {
  display: inline-flex; align-items: center; gap: 10px; padding: 8px 16px 8px 14px;
  border: 1px solid var(--line); border-radius: 999px; background: var(--paper);
  font-size: 14px; text-decoration: none; transition: border-color .2s, box-shadow .2s;
}
.service-index a:hover { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent) inset; }
.service-index .service-no { font-size: 12px; }

.services { display: grid; gap: 20px; }
.service {
  position: relative; display: grid; grid-template-columns: minmax(260px, 5fr) 7fr; gap: clamp(24px, 4vw, 56px);
  padding: 36px clamp(24px, 4vw, 48px) 40px; background: var(--paper);
  border-radius: 8px; overflow: hidden; scroll-margin-top: 88px; transition: box-shadow .3s ease;
}
.service::before { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 4px; background: var(--accent); }
.service:hover { box-shadow: 0 18px 40px -24px rgba(0, 0, 0, .22); }
.service-top { display: flex; justify-content: space-between; align-items: flex-start; }
.service-detail { display: grid; gap: 20px; align-content: start; padding-top: 34px; }
.service-menu { display: grid; grid-template-columns: 1fr 1fr; border-top: 1px solid var(--line); }
.service-menu li {
  display: flex; align-items: baseline; gap: 12px; padding: 14px 4px; font-size: 15px; font-weight: 500;
  border-bottom: 1px solid var(--line);
}
.service-menu li:nth-child(odd) { padding-right: 16px; }
.menu-no { flex: none; font-family: var(--latin); font-size: 12px; letter-spacing: .1em; color: var(--accent); }
.service-no { display: inline-block; font-size: 13px; color: var(--accent); transform: scaleY(.8); transform-origin: left; }
.service-icon svg { width: 44px; height: 44px; fill: none; stroke: var(--accent); stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.service h3 { margin: 14px 0 18px; font-size: 22px; font-weight: 600; letter-spacing: .04em; line-height: 1.5; }
.service-pair { display: grid; gap: 6px; margin-bottom: 18px; padding: 14px 16px; border-radius: 6px; background: var(--tint); font-size: 13px; }
.service-pair div { display: grid; grid-template-columns: 6.5em 1fr; gap: 8px; }
.service-pair dt { color: var(--muted); }
.service-pair dd { font-weight: 600; }
.service p { font-size: 15px; color: #333; }

/* 進め方 */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; position: relative; }
.steps::before {
  content: ""; position: absolute; top: 27px; left: 28px; right: 28px; height: 2px; background: var(--iris); opacity: .5;
}
.step { position: relative; }
.step-node {
  position: relative; display: grid; place-items: center; width: 56px; height: 56px; border-radius: 50%;
  background: var(--paper); border: 2px solid var(--c); color: var(--ink); font-size: 14px; letter-spacing: .1em;
}
.step h3 { margin: 20px 0 8px; font-size: 20px; font-weight: 600; letter-spacing: .06em; }
.step p { font-size: 15px; color: #333; }

/* 会社概要 */
.company { border-top: 1px solid var(--ink); background: transparent; }
.company > div { display: grid; grid-template-columns: 200px 1fr; gap: 24px; padding: 22px 0; border-bottom: 1px solid var(--line); }
.company dt { color: var(--muted); font-size: 14px; padding-top: .15em; }

/* お問い合わせ */
.contact { position: relative; background: var(--ink); color: var(--paper); text-align: center; padding-top: 0; overflow: hidden; }
.contact-helix { opacity: .8; margin-bottom: clamp(56px, 8vw, 96px); padding-top: 8px; }
.contact .label { color: #9a9a9a; transform-origin: center; }
.contact h2 { margin: 10px 0 24px; }
.contact p { color: #cfcfcf; max-width: 32em; margin: 0 auto; }
.mail {
  display: inline-block; margin-top: 36px; padding: 0 .3em 6px;
  font-family: var(--latin); font-size: clamp(20px, 3.4vw, 34px); font-weight: 500; letter-spacing: .04em;
  text-decoration: none; overflow-wrap: anywhere;
  background: var(--iris) left bottom / 100% 2px no-repeat;
  transition: background-size .35s ease, color .35s ease;
}
.mail:hover { background-size: 100% 100%; color: var(--ink); }

/* フッター */
.site-footer { background: var(--ink); color: #8a8a8a; border-top: 1px solid #1c1c1c; }
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding-top: 28px; padding-bottom: 28px; }
.footer-inner img { width: 150px; }
.footer-inner small { font-family: var(--latin); font-size: 12px; letter-spacing: .08em; }

/* タブレット */
@media (max-width: 960px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero-mark { order: -1; width: min(70%, 340px); }
  .philo-grid { grid-template-columns: 1fr; }
  .service { grid-template-columns: 1fr; gap: 8px; }
  .service-detail { padding-top: 0; }
  .steps { grid-template-columns: 1fr 1fr; row-gap: 40px; }
  .steps::before { display: none; }
  .nav-sub { display: none; }
}

/* スマートフォン */
@media (max-width: 600px) {
  .brand img { width: 148px; }
  .views { grid-template-columns: 1fr 1fr; gap: 10px; }
  .view { padding: 12px 10px 14px; }
  .view figcaption { font-size: 12px; }
  .company > div { grid-template-columns: 1fr; gap: 2px; padding: 16px 0; }
  .service { padding: 28px 22px 32px 26px; }
  .service-menu { grid-template-columns: 1fr; }
  .service-menu li:nth-child(odd) { padding-right: 4px; }
  .service-index a { font-size: 13px; padding: 6px 12px 6px 10px; }
  .steps { grid-template-columns: 1fr; row-gap: 28px; }
  .step { display: grid; grid-template-columns: 56px 1fr; column-gap: 18px; }
  .step-node { grid-row: span 2; }
  .step h3 { margin: 4px 0 4px; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .helix-band g > *, .marquee-track, .orbit { animation: none; }
}