@charset "utf-8";

/* =========================================================
   合同会社AItem — Design System
   Palette: Deep Navy × Teal / Refined & Trustworthy
   ========================================================= */

:root{
  /* Ink & surfaces */
  --navy-900:#081522;
  --navy-800:#0B1C2C;
  --navy-700:#112A3E;
  --navy-600:#1B3A52;

  --ink:#0C1A28;
  --ink-2:#22394D;
  --muted:#5E7284;
  --muted-2:#8595A4;

  --line:#E3E9EF;
  --line-soft:#EEF2F6;
  --bg:#FFFFFF;
  --bg-alt:#F6F9FB;

  /* Accent */
  --accent:#0F5C73;
  --accent-2:#14808F;
  --accent-bright:#5FC8D6;
  --accent-soft:#EAF3F6;

  /* Metrics */
  --max:1160px;
  --radius:14px;
  --radius-sm:8px;
  --ease:cubic-bezier(.22,.7,.2,1);

  --shadow-sm:0 1px 2px rgba(12,26,40,.04), 0 4px 16px rgba(12,26,40,.04);
  --shadow-md:0 2px 6px rgba(12,26,40,.05), 0 18px 44px rgba(12,26,40,.09);
}

/* ---------- Base ---------- */
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0;
  font-family:"Inter","Noto Sans JP",-apple-system,BlinkMacSystemFont,"Segoe UI","Hiragino Sans","Yu Gothic UI","Yu Gothic",Meiryo,sans-serif;
  font-size:16px;
  color:var(--ink);
  background:var(--bg);
  line-height:1.9;
  font-feature-settings:"palt" 1;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
a{color:inherit}
img{max-width:100%;display:block}
p{margin:0 0 1em}
p:last-child{margin-bottom:0}

.container{max-width:var(--max);margin:0 auto;padding:0 28px}
.narrow{max-width:860px}

h1,h2,h3,h4{font-weight:700;letter-spacing:-.02em;margin:0}
h1{font-size:clamp(30px,4.6vw,54px);line-height:1.3;letter-spacing:-.035em}
h2{font-size:clamp(24px,2.9vw,34px);line-height:1.42}
h3{font-size:19px;line-height:1.6;letter-spacing:-.01em}

.lead{font-size:clamp(15px,1.25vw,17.5px);line-height:2;color:var(--ink-2)}

/* ---------- Eyebrow ---------- */
.eyebrow{
  display:inline-flex;align-items:center;gap:10px;
  font-size:11px;font-weight:600;letter-spacing:.2em;
  text-transform:uppercase;color:var(--accent-2);
  margin-bottom:14px;
}
.eyebrow::before{
  content:"";width:26px;height:1px;background:currentColor;opacity:.55;flex:none;
}
.on-dark .eyebrow,.dark .eyebrow{color:var(--accent-bright)}

/* ---------- Skip link ---------- */
.skip{position:absolute;left:-9999px;top:0;background:#fff;color:var(--ink);padding:10px 16px;z-index:200;border-radius:0 0 6px 0}
.skip:focus{left:0}

/* =========================================================
   Header
   ========================================================= */
.site-header{
  position:sticky;top:0;z-index:60;
  background:rgba(8,21,34,.94);
  backdrop-filter:saturate(160%) blur(14px);
  -webkit-backdrop-filter:saturate(160%) blur(14px);
  border-bottom:1px solid rgba(255,255,255,.08);
}
.header-inner{
  max-width:var(--max);margin:0 auto;padding:0 28px;
  height:72px;display:flex;align-items:center;justify-content:space-between;gap:24px;
}
.brand{
  display:flex;flex-direction:column;justify-content:center;
  text-decoration:none;color:#fff;line-height:1.15;
}
.brand-name{font-size:21px;font-weight:700;letter-spacing:.02em}
.brand-name span{color:var(--accent-bright)}
.brand-sub{
  font-size:9.5px;font-weight:600;letter-spacing:.24em;
  color:rgba(255,255,255,.5);margin-top:3px;text-transform:uppercase;
}

.site-nav{display:flex;align-items:center;gap:4px}
.site-nav a{
  position:relative;text-decoration:none;font-size:13.5px;font-weight:500;
  color:rgba(255,255,255,.74);padding:9px 14px;border-radius:6px;
  transition:color .22s var(--ease),background .22s var(--ease);
  white-space:nowrap;
}
.site-nav a:hover{color:#fff;background:rgba(255,255,255,.07)}
.site-nav a[aria-current="page"]{color:#fff}
.site-nav a[aria-current="page"]::after{
  content:"";position:absolute;left:14px;right:14px;bottom:2px;height:1.5px;
  background:var(--accent-bright);border-radius:2px;
}
.nav-cta{
  margin-left:10px;padding:9px 18px !important;border-radius:999px;
  background:var(--accent-2);color:#fff !important;font-weight:600;
}
.nav-cta:hover{background:#1796A7 !important}
.nav-cta[aria-current="page"]::after{display:none}

.nav-toggle{
  display:none;width:42px;height:42px;border:1px solid rgba(255,255,255,.18);
  border-radius:8px;background:transparent;cursor:pointer;
  align-items:center;justify-content:center;flex-direction:column;gap:5px;
}
.nav-toggle span{display:block;width:17px;height:1.5px;background:#fff;transition:transform .3s var(--ease),opacity .2s}
.nav-toggle[aria-expanded="true"] span:nth-child(1){transform:translateY(6.5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] span:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] span:nth-child(3){transform:translateY(-6.5px) rotate(-45deg)}

/* =========================================================
   Hero (dark)
   ========================================================= */
.hero{
  position:relative;overflow:hidden;
  background:
    radial-gradient(1000px 520px at 78% -10%, rgba(95,200,214,.20), transparent 62%),
    radial-gradient(760px 460px at 8% 108%, rgba(20,128,143,.26), transparent 66%),
    linear-gradient(168deg, var(--navy-800) 0%, var(--navy-900) 58%, #060F19 100%);
  color:#fff;
}
.hero::before{
  content:"";position:absolute;inset:0;
  background-image:
    linear-gradient(rgba(255,255,255,.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.035) 1px, transparent 1px);
  background-size:76px 76px;
  mask-image:radial-gradient(90% 74% at 50% 34%, #000 32%, transparent 100%);
  -webkit-mask-image:radial-gradient(90% 74% at 50% 34%, #000 32%, transparent 100%);
  pointer-events:none;
}
.hero-inner{
  position:relative;max-width:var(--max);margin:0 auto;padding:96px 28px 104px;
  display:grid;grid-template-columns:minmax(0,1.25fr) minmax(0,.75fr);
  gap:60px;align-items:center;
}
.hero h1{margin:0 0 22px}
.hero .lead{color:rgba(255,255,255,.76);max-width:640px}

.hero-tags{display:flex;flex-wrap:wrap;gap:8px;margin-top:30px}
.hero-tags span{
  font-size:12px;font-weight:500;color:rgba(255,255,255,.78);
  border:1px solid rgba(255,255,255,.18);border-radius:999px;padding:5px 14px;
  background:rgba(255,255,255,.04);
}

.actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:34px}
.btn{
  display:inline-flex;align-items:center;gap:9px;
  text-decoration:none;font-weight:600;font-size:14.5px;
  padding:14px 26px;border-radius:999px;border:1px solid transparent;
  transition:transform .25s var(--ease),background .25s var(--ease),box-shadow .25s var(--ease),border-color .25s var(--ease);
  cursor:pointer;
}
.btn .arw{transition:transform .25s var(--ease)}
.btn:hover .arw{transform:translateX(3px)}
.btn--light{background:#fff;color:var(--navy-900);box-shadow:0 10px 30px rgba(0,0,0,.22)}
.btn--light:hover{transform:translateY(-2px);box-shadow:0 14px 36px rgba(0,0,0,.28)}
.btn--ghost{background:rgba(255,255,255,.04);color:#fff;border-color:rgba(255,255,255,.28)}
.btn--ghost:hover{background:rgba(255,255,255,.11);border-color:rgba(255,255,255,.45);transform:translateY(-2px)}
.btn--accent{background:var(--accent-2);color:#fff}
.btn--accent:hover{background:#12717F;transform:translateY(-2px);box-shadow:0 12px 30px rgba(15,92,115,.28)}

/* Fact panel */
.factbox{
  position:relative;
  background:linear-gradient(180deg, rgba(255,255,255,.085), rgba(255,255,255,.035));
  border:1px solid rgba(255,255,255,.14);
  border-radius:18px;padding:30px 30px 34px;
  box-shadow:0 26px 60px rgba(0,0,0,.30);
  backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px);
}
.factbox .eyebrow{margin-bottom:6px}
.factbox dl{margin:0;display:grid;gap:0}
.factbox dt{
  font-size:10.5px;font-weight:600;letter-spacing:.14em;text-transform:uppercase;
  color:rgba(255,255,255,.5);margin-top:18px;
}
.factbox dd{
  margin:3px 0 0;font-size:14.5px;font-weight:600;color:#fff;line-height:1.75;
  padding-bottom:16px;border-bottom:1px solid rgba(255,255,255,.09);
}
.factbox dl > dd:last-of-type{border-bottom:0;padding-bottom:0}

/* =========================================================
   Page head (dark, inner pages)
   ========================================================= */
.page-head{
  position:relative;overflow:hidden;color:#fff;
  background:
    radial-gradient(760px 340px at 85% -30%, rgba(95,200,214,.18), transparent 62%),
    linear-gradient(160deg, var(--navy-800), var(--navy-900));
}
.page-head::before{
  content:"";position:absolute;inset:0;
  background-image:
    linear-gradient(rgba(255,255,255,.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.03) 1px, transparent 1px);
  background-size:76px 76px;
  mask-image:radial-gradient(85% 100% at 50% 0%, #000 22%, transparent 100%);
  -webkit-mask-image:radial-gradient(85% 100% at 50% 0%, #000 22%, transparent 100%);
}
.page-head .container{position:relative;padding-top:74px;padding-bottom:74px}
.page-head h1{font-size:clamp(28px,3.6vw,42px);margin-bottom:14px}
.page-head p{color:rgba(255,255,255,.72);font-size:16px;margin:0;max-width:640px}

/* Breadcrumb */
.crumb{font-size:12px;color:rgba(255,255,255,.45);margin-bottom:22px;letter-spacing:.04em}
.crumb a{text-decoration:none;color:rgba(255,255,255,.62);transition:color .2s}
.crumb a:hover{color:#fff}
.crumb span{margin:0 8px;opacity:.5}

/* =========================================================
   Sections
   ========================================================= */
.section{padding:96px 0}
.section--tight{padding:72px 0}
.section--alt{background:var(--bg-alt);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}

.section-head{max-width:760px;margin-bottom:46px}
.section-head h2{margin-bottom:16px}
.section-head p{color:var(--muted);font-size:15.5px;margin:0}

/* =========================================================
   Cards
   ========================================================= */
.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:22px}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}

.card{
  position:relative;overflow:hidden;
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:34px 32px 36px;
  transition:transform .35s var(--ease),box-shadow .35s var(--ease),border-color .35s var(--ease);
}
.card::after{
  content:"";position:absolute;left:0;top:0;height:3px;width:100%;
  background:linear-gradient(90deg,var(--accent-2),var(--accent-bright));
  transform:scaleX(0);transform-origin:left;transition:transform .45s var(--ease);
}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-md);border-color:#D4DEE6}
.card:hover::after{transform:scaleX(1)}
.card h3{margin-bottom:12px}
.card p{color:var(--muted);font-size:14.5px;line-height:1.95}

.card-num{
  display:block;font-size:13px;font-weight:700;letter-spacing:.16em;
  color:var(--accent-2);margin-bottom:18px;
}
.card-icon{
  width:46px;height:46px;border-radius:12px;display:flex;align-items:center;justify-content:center;
  background:var(--accent-soft);color:var(--accent);margin-bottom:20px;
}
.card-icon svg{width:22px;height:22px;stroke:currentColor;fill:none;stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round}

.tag{
  display:inline-block;font-size:11px;font-weight:700;letter-spacing:.08em;
  color:var(--accent);background:var(--accent-soft);
  padding:5px 12px;border-radius:999px;margin-bottom:16px;
}

.list{margin:20px 0 0;padding:20px 0 0;list-style:none;border-top:1px solid var(--line-soft)}
.list li{
  position:relative;padding-left:20px;font-size:14px;color:var(--ink-2);margin:.55em 0;line-height:1.8;
}
.list li::before{
  content:"";position:absolute;left:2px;top:.78em;width:6px;height:6px;border-radius:50%;
  background:var(--accent-bright);box-shadow:0 0 0 3px rgba(95,200,214,.18);
}

/* =========================================================
   Feature rows (WHY / table replacement)
   ========================================================= */
.deflist{border-top:1px solid var(--line)}
.deflist .row{
  display:grid;grid-template-columns:260px 1fr;gap:34px;
  padding:28px 4px;border-bottom:1px solid var(--line);
  transition:background .3s var(--ease);
}
.deflist .row:hover{background:rgba(15,92,115,.025)}
.deflist dt,.deflist .k{
  font-size:14px;font-weight:700;color:var(--ink);letter-spacing:.01em;margin:0;
}
.deflist dd,.deflist .v{margin:0;color:var(--muted);font-size:14.5px;line-height:1.95}
.deflist .v a{color:var(--accent-2);text-decoration:none;border-bottom:1px solid rgba(20,128,143,.3);transition:border-color .2s}
.deflist .v a:hover{border-color:var(--accent-2)}

/* =========================================================
   Works / cases
   ========================================================= */
.cases{display:grid;gap:18px}
.case{
  display:grid;grid-template-columns:210px 1fr;gap:34px;align-items:start;
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:32px 34px;
  transition:transform .35s var(--ease),box-shadow .35s var(--ease),border-color .35s var(--ease);
}
.case:hover{transform:translateY(-3px);box-shadow:var(--shadow-md);border-color:#D4DEE6}
.case .meta{display:flex;flex-direction:column;gap:12px}
.case .domain{
  font-size:11.5px;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:var(--muted-2);
}
.case h3{margin-bottom:12px}
.case p{color:var(--muted);font-size:14.5px;line-height:1.95;margin:0}

.chip{
  align-self:flex-start;display:inline-block;
  font-size:11.5px;font-weight:700;letter-spacing:.04em;
  padding:6px 13px;border-radius:6px;
}
.chip--solid{background:var(--accent);color:#fff}
.chip--outline{background:#fff;color:var(--accent);border:1px solid rgba(15,92,115,.35)}
.chip--soft{background:var(--accent-soft);color:var(--accent)}

/* Legend */
.legend{display:flex;flex-wrap:wrap;gap:22px;margin-bottom:34px;padding-bottom:26px;border-bottom:1px solid var(--line)}
.legend div{display:flex;align-items:center;gap:9px;font-size:13px;color:var(--muted)}
.legend .chip{margin:0}

/* =========================================================
   Note
   ========================================================= */
.note{
  position:relative;background:var(--accent-soft);
  border:1px solid rgba(15,92,115,.16);border-left:3px solid var(--accent);
  border-radius:var(--radius-sm);padding:20px 24px;
  color:#3A4C5C;font-size:14px;line-height:1.95;
}
.note strong{color:var(--accent)}

/* =========================================================
   Contact
   ========================================================= */
.contact-grid{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr);gap:24px;align-items:start}

.panel{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:38px 36px;
  box-shadow:var(--shadow-sm);
}
.panel--dark{
  background:linear-gradient(165deg,var(--navy-700),var(--navy-900));
  border-color:rgba(255,255,255,.1);color:#fff;
}
.panel--dark h3{color:#fff}
.panel h3{margin-bottom:10px}
.panel > p{color:var(--muted);font-size:14.5px}
.panel--dark > p{color:rgba(255,255,255,.72)}

.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.field{margin-top:18px}
.field:first-child{margin-top:0}
label{
  display:block;font-size:12px;font-weight:700;letter-spacing:.08em;
  color:var(--ink-2);margin-bottom:8px;
}
label .req{color:var(--accent-2);font-size:10px;margin-left:6px;letter-spacing:.06em}
input,textarea,select{
  width:100%;padding:13px 15px;font:inherit;font-size:15px;
  border:1px solid #D3DCE4;border-radius:var(--radius-sm);background:#FBFDFE;color:var(--ink);
  transition:border-color .22s var(--ease),box-shadow .22s var(--ease),background .22s;
}
input:focus,textarea:focus{
  outline:none;border-color:var(--accent-2);background:#fff;
  box-shadow:0 0 0 3px rgba(20,128,143,.13);
}
textarea{min-height:170px;resize:vertical;line-height:1.85}
button{border:0;cursor:pointer;font:inherit}

.info-list{list-style:none;margin:24px 0 0;padding:0}
.info-list li{
  display:grid;grid-template-columns:76px 1fr;gap:16px;align-items:baseline;
  padding:13px 0;border-top:1px solid rgba(255,255,255,.1);font-size:14.5px;
}
.info-list li:first-child{border-top:0;padding-top:0}
.info-list .k{
  font-size:10.5px;font-weight:600;letter-spacing:.14em;text-transform:uppercase;
  color:rgba(255,255,255,.5);
}
.info-list .v{color:#fff;line-height:1.75}
.info-list .v a{color:var(--accent-bright);text-decoration:none;border-bottom:1px solid rgba(95,200,214,.4)}
.note--dark{
  background:rgba(255,255,255,.06);border-color:rgba(255,255,255,.12);
  border-left-color:var(--accent-bright);color:rgba(255,255,255,.75);margin-top:26px;
}

/* =========================================================
   CTA band
   ========================================================= */
.cta{
  position:relative;overflow:hidden;color:#fff;
  background:
    radial-gradient(700px 320px at 15% 0%, rgba(95,200,214,.20), transparent 60%),
    linear-gradient(140deg,var(--navy-700),var(--navy-900));
}
.cta .container{
  position:relative;padding-top:76px;padding-bottom:76px;
  display:flex;align-items:center;justify-content:space-between;gap:36px;flex-wrap:wrap;
}
.cta h2{font-size:clamp(22px,2.4vw,30px);margin-bottom:10px}
.cta p{color:rgba(255,255,255,.7);font-size:15px;margin:0}

/* =========================================================
   Footer
   ========================================================= */
.site-footer{background:var(--navy-900);color:rgba(255,255,255,.66);padding:64px 0 0}
.footer-top{
  display:grid;grid-template-columns:minmax(0,1.5fr) minmax(0,1fr) minmax(0,1fr);
  gap:44px;padding-bottom:48px;
}
.footer-brand .brand-name{font-size:22px;color:#fff}
.footer-brand .brand-sub{margin-bottom:20px}
.footer-brand address{font-style:normal;font-size:13.5px;line-height:1.95;color:rgba(255,255,255,.6)}
.footer-col h4{
  font-size:10.5px;font-weight:600;letter-spacing:.18em;text-transform:uppercase;
  color:rgba(255,255,255,.42);margin-bottom:18px;
}
.footer-col ul{list-style:none;margin:0;padding:0}
.footer-col li{margin:0 0 11px}
.footer-col a{
  text-decoration:none;font-size:14px;color:rgba(255,255,255,.72);
  transition:color .2s var(--ease);
}
.footer-col a:hover{color:var(--accent-bright)}
.footer-bottom{
  border-top:1px solid rgba(255,255,255,.09);
  padding:22px 0 30px;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;
  font-size:12.5px;color:rgba(255,255,255,.42);
}

/* =========================================================
   Reveal animation
   ========================================================= */
.reveal{opacity:0;transform:translateY(16px)}
.reveal.is-visible{
  opacity:1;transform:none;
  transition:opacity .7s var(--ease),transform .7s var(--ease);
}
.reveal.d1{transition-delay:.08s}
.reveal.d2{transition-delay:.16s}
.reveal.d3{transition-delay:.24s}

@media (prefers-reduced-motion: reduce){
  *{animation:none !important;transition:none !important;scroll-behavior:auto !important}
  .reveal{opacity:1;transform:none}
}

/* =========================================================
   Responsive
   ========================================================= */
@media (max-width:1000px){
  .hero-inner{grid-template-columns:1fr;gap:44px;padding:76px 28px 84px}
  .grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .contact-grid{grid-template-columns:1fr}
  .footer-top{grid-template-columns:1fr 1fr;gap:34px}
  .footer-brand{grid-column:1 / -1}
}

@media (max-width:860px){
  .site-nav{
    position:absolute;left:0;right:0;top:100%;
    flex-direction:column;align-items:stretch;gap:0;
    background:var(--navy-900);border-bottom:1px solid rgba(255,255,255,.1);
    padding:10px 18px 20px;
    display:none;
  }
  .site-nav.is-open{display:flex}
  .site-nav a{padding:14px 8px;font-size:15px;border-radius:0}
  .site-nav a + a{border-top:1px solid rgba(255,255,255,.07)}
  .site-nav a[aria-current="page"]::after{left:8px;right:auto;width:18px;bottom:8px}
  .nav-cta{margin:14px 8px 0;text-align:center;border-radius:999px}
  .nav-cta[aria-current="page"]::after{display:none}
  .nav-toggle{display:flex}
  .site-header{position:sticky}
  .header-inner{position:relative}
}

@media (max-width:720px){
  .container{padding:0 20px}
  .section{padding:66px 0}
  .section--tight{padding:52px 0}
  .grid{grid-template-columns:1fr}
  .case{grid-template-columns:1fr;gap:18px;padding:26px 24px}
  .case .meta{flex-direction:row;align-items:center;gap:14px;flex-wrap:wrap}
  .deflist .row{grid-template-columns:1fr;gap:8px;padding:22px 2px}
  .form-grid{grid-template-columns:1fr}
  .panel{padding:30px 24px}
  .page-head .container{padding-top:54px;padding-bottom:54px}
  .hero-inner{padding:60px 20px 68px}
  .factbox{padding:26px 24px 28px}
  .footer-top{grid-template-columns:1fr;gap:34px}
  .actions{gap:10px}
  .btn{padding:13px 22px;font-size:14px}
  .legend{gap:14px}
  .eyebrow{font-size:10px;letter-spacing:.14em}
  .eyebrow::before{width:18px}
  .actions .btn{flex:1 1 auto;justify-content:center}
}