/* ============================================================
   合同会社ネクサス
   濃灰紫に蛍光緑。実験室のような静けさ
   軸: 定款4 ソフトウェア
   組み: hero=letterbox / 事業=accordion / 進め方=steps-arrow / ボタン=bracket
   節の並び: concept → company → business → flow → faq
   文章: 社名の比喩に寄せない。体言止めを使わない。（_shared/design-brief.md）
   ============================================================ */
:root{
  --bg:#1c1a24; --bg2:#25222f; --panel:#141219;
  --ink:#e9e6ef; --ink2:#b0aabf; --ink3:#807a90;
  --key:#8fd66a; --key2:#6cb046; --hair:rgba(233,230,239,.15);
  --keyfaint:#8fd66a1f;
  --veil:linear-gradient(180deg,rgba(0,0,0,.35),rgba(0,0,0,.66));
  --r:3px;
  --head:"Murecho",sans-serif; --lat:"JetBrains Mono",monospace;
  --wrap:1160px; --pad:clamp(1.3rem,4.5vw,4.2rem);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{font-family:"Murecho",system-ui,-apple-system,Meiryo,sans-serif;background:var(--bg);color:var(--ink);
  line-height:2.05;font-size:15.5px;letter-spacing:.03em;overflow-x:hidden;-webkit-font-smoothing:antialiased;
  line-break:strict;word-break:auto-phrase}
p,li,dd,td,.sub,.a,.note-line{text-wrap:pretty}
h1,h2,h3,h4{text-wrap:balance;line-break:strict;word-break:auto-phrase;font-family:var(--head)}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
::selection{background:var(--key);color:#1c1a24}
.lat{font-family:var(--lat);letter-spacing:.22em;text-transform:uppercase;font-size:.66rem;color:var(--key)}
.wrap{max-width:var(--wrap);margin:0 auto;padding-left:var(--pad);padding-right:var(--pad)}
.progress{position:fixed;top:0;left:0;height:2px;width:0;background:var(--key);z-index:90;transition:width .1s linear}

/* header */
.site-header{position:fixed;inset:0 0 auto 0;z-index:80;display:flex;align-items:center;justify-content:space-between;
  padding:19px var(--pad);transition:background .4s,padding .4s;color:var(--ink)}
.site-header.solid{background:#1c1a24f0;backdrop-filter:blur(9px);
  padding-top:12px;padding-bottom:12px;box-shadow:0 1px 0 var(--hair)}
.brand{display:flex;align-items:center;gap:12px}
.brand .mono{width:36px;height:36px;border:1px solid var(--key);border-radius:var(--r);
  display:grid;place-items:center;font-family:var(--lat);font-size:.95rem;color:var(--key);flex:none}
.brand .bt b{display:block;font-family:var(--head);font-weight:600;font-size:.95rem;letter-spacing:.08em}
.brand .bt span{font-family:var(--lat);font-size:.55rem;letter-spacing:.26em;color:var(--ink3)}
.nav{display:flex;align-items:center;gap:24px}
.nav a{font-size:.79rem;letter-spacing:.09em}
.nav a:not(.nav-cta):hover,.nav a[aria-current=page]:not(.nav-cta){color:var(--key)}
.nav .nav-cta{border:1px solid var(--key);color:var(--key);border-radius:3px;padding:8px 19px;font-size:.73rem;
  transition:background .3s,color .3s}
.nav .nav-cta:hover{background:var(--key);color:#1c1a24}
.nav-toggle{display:none}

/* hero（letterbox） */
.hero{position:relative;padding:clamp(6.2rem,10vw,7.6rem) 0 clamp(3rem,7vw,5rem);background:var(--bg)}
.hero-art{max-width:var(--wrap);margin:0 auto clamp(1.8rem,4vw,2.8rem);padding:0 var(--pad)}
.hero-art span{display:block;overflow:hidden;border-radius:var(--r)}
.hero-art img{width:100%;aspect-ratio:21/5;object-fit:cover;transform:scale(1.12);opacity:0;
  transition:transform 1.9s cubic-bezier(.16,1,.3,1),opacity 1.3s}
.hero.lit .hero-art img{transform:scale(1);opacity:1}
.hero-inner{max-width:var(--wrap);margin:0 auto;padding:0 var(--pad)}
.hero .lat{display:block;margin-bottom:1.2rem;opacity:0;transition:opacity .9s .55s}
.hero.lit .lat{opacity:1}
.hero h1{font-weight:700;font-size:clamp(1.9rem,5.2vw,3.5rem);line-height:1.6;letter-spacing:.03em}
.hero h1 .ln{display:block;overflow:hidden}
.hero h1 .ln em{display:block;font-style:normal;transform:translateY(108%);transition:transform 1s cubic-bezier(.16,1,.3,1) .5s}
.hero h1 .ln:nth-child(2) em{transition-delay:.62s}
.hero.lit h1 .ln em{transform:none}
.hero .sub{margin-top:1.8rem;max-width:32rem;color:var(--ink2);font-size:.95rem;opacity:0;transition:opacity 1s 1s}
.hero.lit .sub{opacity:1}
.hero-actions{margin-top:2.3rem;display:flex;gap:13px;flex-wrap:wrap;opacity:0;transition:opacity 1s 1.2s}
.hero.lit .hero-actions{opacity:1}

/* ボタン（bracket） */
.btn{position:relative;display:inline-flex;align-items:center;gap:.7em;font-size:.82rem;font-weight:600;letter-spacing:.1em;
  padding:14px 26px;color:var(--ink);transition:color .3s}
.btn::before,.btn::after{content:"";position:absolute;top:0;bottom:0;width:9px;border:1.5px solid var(--key);transition:width .35s}
.btn::before{left:0;border-right:0}
.btn::after{right:0;border-left:0}
.btn:hover::before,.btn:hover::after{width:16px}
.btn-key{background:var(--key);color:var(--bg);font-weight:700}
.btn-key::before,.btn-key::after{border-color:var(--key)}

/* section */
.section{padding:clamp(4.6rem,11vw,8.6rem) 0;position:relative}
.section.tone{background:var(--bg2)}
.section.panel{background:var(--panel)}
.sec-head{margin-bottom:clamp(2.2rem,5vw,3.6rem);max-width:45rem}
.sec-head .lat{display:block;margin-bottom:.8rem}
.sec-head h2{font-weight:600;font-size:clamp(1.45rem,3.6vw,2.35rem);line-height:1.6;letter-spacing:.05em}
.sec-head p{margin-top:1.1rem;color:var(--ink2)}
.mb{margin-bottom:clamp(2.2rem,5vw,3.6rem)}

/* 事業（accordion） */
.biz-acc{border-top:1px solid var(--hair)}
.biz-acc details{border-bottom:1px solid var(--hair)}
.biz-acc summary{list-style:none;cursor:pointer;display:grid;grid-template-columns:auto minmax(0,1fr) auto;
  gap:clamp(.9rem,2.4vw,1.8rem);align-items:center;padding:clamp(1.4rem,3vw,2rem) 0}
.biz-acc summary::-webkit-details-marker{display:none}
.biz-acc summary .n{font-family:var(--lat);font-size:.68rem;letter-spacing:.2em;color:var(--key)}
.biz-acc summary h3{font-family:var(--head);font-weight:600;font-size:clamp(1.02rem,2.4vw,1.3rem);line-height:1.7}
.biz-acc summary .mk{width:12px;height:12px;border-right:1.5px solid var(--ink3);border-bottom:1.5px solid var(--ink3);
  transform:rotate(45deg);transition:transform .25s}
.biz-acc details[open] summary .mk{transform:rotate(-135deg)}
.biz-acc .body{padding:0 0 clamp(1.5rem,3vw,2.2rem) clamp(0px,6vw,5.2rem);max-width:46rem}
.biz-acc .body p{color:var(--ink2);font-size:.93rem}
.biz-acc .body p+p{margin-top:.8rem}
.biz-acc details.lead summary h3::after{content:"　柱となる事業";font-family:var(--lat);font-size:.58rem;letter-spacing:.14em;color:var(--key)}
.note-line{margin-top:1.9rem;font-size:.79rem;color:var(--ink3);max-width:46rem}
.note-line a{color:var(--key);text-decoration:underline;text-underline-offset:3px}

/* 考え方 */
.creed{max-width:44rem}
.creed .big{font-family:var(--head);font-weight:600;font-size:clamp(1.3rem,3.3vw,2.05rem);line-height:1.7;margin-bottom:1.4rem}
.creed p{color:var(--ink2);margin-top:.95rem}
.creed-fig{margin-top:clamp(2.2rem,5vw,3.6rem);overflow:hidden;border-radius:var(--r)}
.creed-fig img{width:100%;aspect-ratio:24/9;object-fit:cover;transform:scale(1.08);transition:transform 1.7s cubic-bezier(.16,1,.3,1)}
.reveal.on .creed-fig img,.creed-fig.reveal.on img{transform:scale(1)}

/* 進め方（steps-arrow） */
.flow-steps{display:grid;gap:.75rem;max-width:48rem}
.flow-steps .s{display:grid;grid-template-columns:3.6rem minmax(0,1fr);gap:clamp(.9rem,2.4vw,1.8rem);align-items:start;
  background:var(--panel);border:1px solid var(--hair);border-radius:var(--r);padding:clamp(1.1rem,2.4vw,1.6rem) clamp(1rem,2.4vw,1.6rem);position:relative}
.flow-steps .s::after{content:"";position:absolute;left:2rem;bottom:-.62rem;width:8px;height:8px;
  border-right:2px solid var(--key);border-bottom:2px solid var(--key);transform:translateX(-50%) rotate(45deg);z-index:2}
.flow-steps .s:last-child::after{display:none}
.flow-steps .n{font-family:var(--lat);font-weight:700;font-size:1.35rem;color:var(--key);line-height:1.3}
.flow-steps h4{font-family:var(--head);font-weight:600;font-size:1rem;margin-bottom:.35rem}
.flow-steps p{font-size:.9rem;color:var(--ink2)}

/* 対応範囲 */
.scope{display:flex;flex-wrap:wrap;gap:.65rem}
.scope span{border:1px solid var(--hair);border-radius:999px;padding:8px 19px;
  font-size:.83rem;color:var(--ink2);background:var(--panel)}

/* 会社概要 */
.table-info{width:100%;border-collapse:collapse;font-size:.93rem}
.table-info th,.table-info td{border-top:1px solid var(--hair);padding:1.2rem .2rem;text-align:left;vertical-align:top}
.table-info th{width:11rem;font-weight:600;color:var(--ink3);font-size:.8rem;letter-spacing:.1em}
.table-info tr:last-child td,.table-info tr:last-child th{border-bottom:1px solid var(--hair)}

/* 質問 */
.faq{max-width:46rem}
.faq details{border-bottom:1px solid var(--hair);padding:1.3rem 0}
.faq details:first-child{border-top:1px solid var(--hair)}
.faq summary{list-style:none;cursor:pointer;display:flex;gap:.9rem;align-items:flex-start;
  font-family:var(--head);font-weight:600;font-size:.99rem;line-height:1.75}
.faq summary::-webkit-details-marker{display:none}
.faq summary::before{content:"Q";font-family:var(--lat);color:var(--key);flex:none;padding-top:.15em}
.faq summary::after{content:"";margin-left:auto;flex:none;width:11px;height:11px;margin-top:.55em;
  border-right:1.5px solid var(--ink3);border-bottom:1.5px solid var(--ink3);transform:rotate(45deg);transition:transform .25s}
.faq details[open] summary::after{transform:rotate(-135deg)}
.faq .a{padding:.9rem 0 0 1.9rem;color:var(--ink2);font-size:.91rem}

.cta{background:var(--key);color:#1c1a24;padding:clamp(4.2rem,10vw,7rem) 0}
.cta .lat{color:inherit;opacity:.75;display:block}
.cta h2{font-weight:600;font-size:clamp(1.45rem,3.6vw,2.3rem);margin:1rem 0 .9rem;line-height:1.6}
.cta p{opacity:.85;margin-bottom:2.1rem;max-width:33rem}
.cta .btn{border-color:currentColor;color:inherit}
.cta .btn::before{background:#1c1a24}
.cta .btn:hover{color:var(--key)}

.page-hero{padding:clamp(7.6rem,14vw,10.5rem) var(--pad) clamp(2.4rem,5.5vw,3.9rem);background:var(--bg2);border-bottom:1px solid var(--hair)}
.page-hero .lat{display:block;margin-bottom:.8rem}
.page-hero h1{font-weight:600;font-size:clamp(1.65rem,4.4vw,2.8rem);letter-spacing:.07em}

.prose{max-width:45rem}
.prose h2{font-weight:600;font-size:1.07rem;margin:2.5rem 0 .85rem;padding-bottom:.5rem;border-bottom:1px solid var(--hair)}
.prose h2:first-child{margin-top:0}
.prose p,.prose li{color:var(--ink2);font-size:.93rem}
.prose ul,.prose ol{margin:.5rem 0 .5rem 1.4rem}.prose li{margin:.3rem 0}
.prose .stamp{font-size:.78rem;color:var(--ink3);margin-top:2.2rem}

.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:clamp(2rem,5vw,4rem);max-width:60rem;align-items:start}
.contact-grid h3{font-family:var(--head);font-weight:600;font-size:1rem;color:var(--key);
  padding-bottom:.5rem;border-bottom:1px solid var(--hair);margin-bottom:.9rem}
.contact-grid p{line-height:2}
.mail{font-family:var(--lat);font-size:clamp(1.02rem,2.5vw,1.28rem);letter-spacing:.02em;color:var(--key);margin-top:.3rem;word-break:break-all}
.tiny{font-size:.78rem;color:var(--ink3);line-height:1.9;margin-top:.5rem}
.form{display:grid;gap:1.1rem;margin-top:1.2rem}
.form label{font-size:.76rem;letter-spacing:.09em;color:var(--ink3);display:block}
.form input,.form textarea{width:100%;border:1px solid var(--hair);border-radius:var(--r);padding:.8rem .9rem;
  font-family:inherit;font-size:.95rem;line-height:1.8;background:var(--panel);color:var(--ink);margin-top:.35rem}
.form input:focus,.form textarea:focus{outline:2px solid var(--key);border-color:var(--key)}
.form input:disabled,.form textarea:disabled{background:var(--bg2);color:var(--ink3);cursor:not-allowed}
.form .btn{justify-self:start}
.form .btn:disabled{opacity:.4;pointer-events:none}

.site-footer{background:var(--panel);color:var(--ink2);padding:clamp(3.4rem,8vw,5.2rem) var(--pad) 2rem;border-top:1px solid var(--hair)}
.footer-top{max-width:var(--wrap);margin:0 auto;display:flex;justify-content:space-between;gap:2.6rem;flex-wrap:wrap}
.footer-brand .mono{width:40px;height:40px;border:1px solid var(--key);border-radius:var(--r);
  display:grid;place-items:center;font-family:var(--lat);color:var(--key)}
.footer-brand b{display:block;margin-top:.9rem;color:var(--ink);font-family:var(--head);font-weight:600;font-size:.96rem;letter-spacing:.08em}
.footer-addr{font-size:.8rem;margin-top:.7rem;line-height:1.95}
.footer-nav{display:grid;grid-template-columns:1fr 1fr;gap:.5rem 2.2rem;font-size:.8rem}
.footer-nav a:hover{color:var(--key)}
.footer-bottom{max-width:var(--wrap);margin:2.4rem auto 0;padding-top:1.3rem;border-top:1px solid var(--hair);
  font-family:var(--lat);font-size:.68rem;letter-spacing:.18em;color:var(--ink3)}

.reveal{opacity:0;transform:translateY(22px);transition:opacity 1s cubic-bezier(.2,.7,.2,1),transform 1s cubic-bezier(.2,.7,.2,1)}
.reveal.on{opacity:1;transform:none}
.reveal[data-d="1"]{transition-delay:.12s}

@media(max-width:960px){
  .hero .hero-inner{grid-template-columns:1fr!important}
  .hero-art{position:static!important;width:auto!important}
  .biz-lead,.biz-sub,.contact-grid{grid-template-columns:1fr}
  .biz-lead .fig{order:0}
}
@media(max-width:680px){
  .nav a:not(.nav-cta){display:none}
  .nav-toggle{display:flex;flex-direction:column;justify-content:center;gap:5px;width:36px;height:30px;background:none;border:0;cursor:pointer}
  .nav-toggle span{display:block;width:22px;height:1.6px;margin-left:auto;background:currentColor;transition:transform .25s,opacity .2s}
  .nav-toggle.on span:nth-child(1){transform:translateY(6.6px) rotate(45deg)}
  .nav-toggle.on span:nth-child(2){opacity:0}
  .nav-toggle.on span:nth-child(3){transform:translateY(-6.6px) rotate(-45deg)}
  .nav.menu-open{position:fixed;inset:0;background:var(--bg);flex-direction:column;justify-content:center;align-items:center;gap:1.7rem}
  .nav.menu-open a:not(.nav-cta){display:block;font-size:1.05rem;letter-spacing:.15em}
  .footer-top{flex-direction:column;gap:1.6rem}.footer-nav{grid-template-columns:1fr}
}
@media(prefers-reduced-motion:reduce){
  .reveal,.hero h1 .ln em,.hero .sub,.hero-actions,.hero .lat,.hero-art img,.hero-art::after,.hero-mark{
    transition:none;opacity:1;transform:none;clip-path:none}
  .hero-art::after{display:none}
}