/* =========================================================
   SOLAB Website — Shared Stylesheet
   Modern / technical / professional / clean / spacious.
   No gradients, no stock photography, no heavy motion.
   ========================================================= */

:root{
  --ink:        #10161c;   /* primary text / near-black navy */
  --ink-soft:   #3d4a56;   /* secondary text */
  --line:       #dfe4e8;   /* hairline borders */
  --line-soft:  #eef1f3;
  --paper:      #ffffff;
  --paper-alt:  #f5f7f8;   /* section alt background */
  --navy:       #0f2436;   /* brand deep navy */
  --steel:      #2f6690;   /* brand steel blue accent */
  --steel-dark: #1d4e6f;
  --signal:     #d9622b;   /* single accent for CTAs / emphasis */
  --signal-dark:#b84f20;
  --radius:     2px;
  --maxw:       1180px;
  --gutter:     24px;
  font-size: 16px;
}

*{ box-sizing:border-box; }
html,body{ margin:0; padding:0; }
body{
  color: var(--ink);
  background: var(--paper);
  font-family: "Inter", "Noto Sans JP", -apple-system, "Hiragino Sans", "Yu Gothic", sans-serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
html[lang="ja"] body{
  font-family: "Noto Sans JP", "Inter", -apple-system, "Hiragino Sans", "Yu Gothic", sans-serif;
  letter-spacing: 0.01em;
}

img{ max-width:100%; display:block; }
a{ color: inherit; text-decoration: none; }
ul{ margin:0; padding:0; list-style:none; }
h1,h2,h3,h4{ margin:0; font-weight:700; color:var(--navy); letter-spacing:-0.01em; }
p{ margin:0; }
button{ font-family:inherit; }

.wrap{
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

/* ---------- Skip link (a11y) ---------- */
.skip-link{
  position:absolute; left:-999px; top:0;
  background:var(--navy); color:#fff; padding:10px 16px; z-index:200;
}
.skip-link:focus{ left: var(--gutter); top: 8px; }

/* ---------- Top utility bar ---------- */
.utility-bar{
  background: var(--navy);
  color: #cfd9e2;
  font-size: 12.5px;
}
.utility-bar .wrap{
  display:flex; align-items:center; justify-content:flex-end;
  gap:18px; padding-top:7px; padding-bottom:7px;
}
.utility-bar a{ color:#cfd9e2; }
.utility-bar a:hover{ color:#fff; }
.lang-switch{
  display:flex; align-items:center; gap:6px;
  border-left:1px solid rgba(255,255,255,.2); padding-left:16px;
}
.lang-switch span[aria-current="true"]{ color:#fff; font-weight:600; }
.lang-switch a:hover{ color:#fff; }

/* ---------- Header / nav ---------- */
.site-header{
  position: sticky; top:0; z-index:100;
  background: rgba(255,255,255,.96);
  border-bottom: 1px solid var(--line);
  backdrop-filter: saturate(140%) blur(6px);
}
.site-header .wrap{
  display:flex; align-items:center; justify-content:space-between;
  padding-top:14px; padding-bottom:14px;
}
.brand{ display:flex; align-items:center; gap:10px; }
.brand .mark{ width:30px; height:30px; flex:none; }
.brand .name{ font-size:19px; font-weight:800; color:var(--navy); letter-spacing:.02em; }
.brand .legal{ display:block; font-size:10.5px; color:var(--ink-soft); font-weight:500; letter-spacing:.02em; }

.main-nav{ display:flex; align-items:center; gap:30px; }
.main-nav ul{ display:flex; gap:26px; }
.main-nav a{
  font-size:14.5px; font-weight:600; color:var(--ink-soft);
  padding:6px 2px; border-bottom:2px solid transparent;
}
.main-nav a:hover, .main-nav a[aria-current="page"]{
  color: var(--navy); border-bottom-color: var(--signal);
}
.nav-cta{
  display:inline-flex; align-items:center;
  background: var(--navy); color:#fff !important;
  font-size:13.5px; font-weight:700; padding:10px 18px;
  border-radius: var(--radius); white-space:nowrap;
}
.nav-cta:hover{ background: var(--steel-dark); }

.nav-toggle{
  display:none; background:none; border:1px solid var(--line);
  padding:8px 10px; border-radius:var(--radius); cursor:pointer;
}
.nav-toggle span{ display:block; width:20px; height:2px; background:var(--navy); margin:4px 0; }

/* ---------- Hero ---------- */
.hero{
  background: var(--navy);
  color: #eef2f5;
  padding: 88px 0 72px;
  position: relative;
  overflow:hidden;
}
.hero::before{
  content:"";
  position:absolute; inset:0;
  background-image:
    linear-gradient(90deg, rgba(255,255,255,.05) 1px, transparent 1px),
    linear-gradient(0deg, rgba(255,255,255,.05) 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: linear-gradient(180deg, transparent, rgba(0,0,0,.55) 55%, transparent);
  pointer-events:none;
}
.hero .wrap{ position:relative; }
.hero-kicker{
  display:inline-block; font-size:12.5px; font-weight:700; letter-spacing:.14em;
  text-transform:uppercase; color:#9fb7c8; margin-bottom:18px;
}
.hero h1{
  color:#fff; font-size:42px; line-height:1.25; max-width:820px; margin-bottom:22px;
}
.hero .lede{
  font-size:17.5px; color:#c7d3dc; max-width:640px; margin-bottom:32px;
}
.hero-actions{ display:flex; gap:14px; flex-wrap:wrap; }

.page-hero{
  background:var(--navy); color:#fff; padding:56px 0 44px;
}
.page-hero h1{ color:#fff; font-size:32px; max-width:760px; }
.page-hero .lede{ color:#c7d3dc; max-width:680px; margin-top:14px; font-size:16px; }
.breadcrumb{ font-size:12.5px; color:#9fb7c8; margin-bottom:14px; }
.breadcrumb a{ color:#c7d3dc; }
.breadcrumb a:hover{ color:#fff; }

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex; align-items:center; gap:8px;
  font-size:14.5px; font-weight:700; padding:13px 24px;
  border-radius:var(--radius); border:1px solid transparent; cursor:pointer;
}
.btn-primary{ background: var(--signal); color:#fff; }
.btn-primary:hover{ background: var(--signal-dark); }
.btn-ghost{ background:transparent; color:#fff; border-color: rgba(255,255,255,.45); }
.btn-ghost:hover{ border-color:#fff; }
.btn-outline{ background:transparent; color:var(--navy); border-color: var(--line); }
.btn-outline:hover{ border-color: var(--navy); }

/* ---------- Sections ---------- */
section{ padding: 76px 0; }
.section-alt{ background: var(--paper-alt); }
.section-head{ max-width:720px; margin-bottom:44px; }
.eyebrow{
  display:block; font-size:12.5px; font-weight:700; letter-spacing:.12em;
  text-transform:uppercase; color: var(--steel); margin-bottom:12px;
}
.section-head h2{ font-size:29px; line-height:1.3; }
.section-head .lede{ color:var(--ink-soft); font-size:16px; margin-top:14px; }

/* ---------- Grids / cards ---------- */
.grid{ display:grid; gap:26px; }
.grid-2{ grid-template-columns: repeat(2, 1fr); }
.grid-3{ grid-template-columns: repeat(3, 1fr); }
.grid-4{ grid-template-columns: repeat(4, 1fr); }

.card{
  background:#fff; border:1px solid var(--line); border-radius:var(--radius);
  padding:28px; height:100%;
}
.card h3{ font-size:18px; margin-bottom:10px; }
.card p{ color:var(--ink-soft); font-size:14.5px; }
.card .icon{ width:34px; height:34px; margin-bottom:16px; color:var(--steel); }
.card-link{
  display:inline-flex; align-items:center; gap:6px; margin-top:16px;
  font-size:13.5px; font-weight:700; color:var(--steel-dark);
}
.card.is-link:hover{ border-color: var(--steel); }
.card.is-link:hover .card-link{ color: var(--signal); }

/* Process row */
.process{ display:grid; grid-template-columns: repeat(5,1fr); gap:0; counter-reset:step; }
.process li{
  position:relative; padding:22px 18px 0 0; border-top:3px solid var(--line);
}
.process li::before{
  counter-increment:step; content:counter(step);
  position:absolute; top:-14px; left:0;
  width:26px; height:26px; border-radius:50%;
  background:var(--navy); color:#fff; font-size:12px; font-weight:700;
  display:flex; align-items:center; justify-content:center;
}
.process li.is-active::before{ background:var(--signal); }
.process h3{ font-size:15.5px; margin-bottom:8px; }
.process p{ font-size:13.5px; color:var(--ink-soft); }

/* Applications grid */
.app-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:20px; }
.app-item{
  border:1px solid var(--line); border-radius:var(--radius); padding:22px;
  background:#fff;
}
.app-item h3{ font-size:15.5px; margin-bottom:8px; }
.app-item p{ font-size:13.5px; color:var(--ink-soft); }
.app-item .tag{
  display:inline-block; font-size:11px; font-weight:700; letter-spacing:.06em;
  text-transform:uppercase; color:var(--steel); margin-bottom:10px;
}

/* Case studies */
.case-card{
  border:1px solid var(--line); border-radius:var(--radius); background:#fff;
  padding:30px; display:grid; grid-template-columns: 1fr 2fr; gap:28px;
}
.case-card + .case-card{ margin-top:22px; }
.case-tag{
  display:inline-block; font-size:11px; font-weight:700; letter-spacing:.06em;
  text-transform:uppercase; color:var(--signal); margin-bottom:10px;
}
.case-meta dt{ font-size:11px; text-transform:uppercase; letter-spacing:.06em; color:var(--ink-soft); margin-top:14px; }
.case-meta dt:first-child{ margin-top:0; }
.case-meta dd{ margin:4px 0 0; font-size:14.5px; font-weight:600; color:var(--navy); }
.case-body h3{ font-size:19px; margin-bottom:10px; }
.case-row{ margin-bottom:14px; }
.case-row .label{ font-size:12.5px; font-weight:700; color:var(--steel-dark); display:block; margin-bottom:4px; }
.case-row p{ font-size:14.5px; color:var(--ink-soft); }
.case-note{
  margin-top:34px; padding:16px 20px; border:1px dashed var(--line);
  border-radius:var(--radius); font-size:13.5px; color:var(--ink-soft); background:var(--paper-alt);
}

/* Partners */
.partner-card{
  border:1px solid var(--line); border-radius:var(--radius); background:#fff;
  padding:32px; display:grid; grid-template-columns: 220px 1fr; gap:30px; align-items:start;
}
.partner-card + .partner-card{ margin-top:22px; }
.partner-id .logo-mark{
  width:100%; aspect-ratio:16/9; border:1px solid var(--line); border-radius:var(--radius);
  display:flex; align-items:center; justify-content:center; background:var(--paper-alt);
  font-weight:800; color:var(--navy); font-size:20px; letter-spacing:.02em;
}
.partner-id .role{ display:block; margin-top:12px; font-size:12px; font-weight:700; color:var(--steel); letter-spacing:.05em; text-transform:uppercase; }
.partner-body h3{ font-size:19px; margin-bottom:6px; }
.partner-body .est{ font-size:13px; color:var(--ink-soft); margin-bottom:14px; }
.partner-body p{ font-size:14.5px; color:var(--ink-soft); }

/* About / history */
.timeline{ border-left:2px solid var(--line); margin-left:6px; }
.timeline li{ position:relative; padding:0 0 34px 30px; }
.timeline li:last-child{ padding-bottom:0; }
.timeline li::before{
  content:""; position:absolute; left:-7px; top:2px;
  width:12px; height:12px; border-radius:50%; background:var(--steel); border:2px solid #fff;
  box-shadow:0 0 0 2px var(--line);
}
.timeline .year{ font-size:13px; font-weight:800; color:var(--signal); letter-spacing:.04em; }
.timeline h3{ font-size:16.5px; margin:4px 0 6px; }
.timeline p{ font-size:14px; color:var(--ink-soft); }

.philosophy-list li{ display:flex; gap:16px; padding:18px 0; border-top:1px solid var(--line); }
.philosophy-list li:first-child{ border-top:none; }
.philosophy-list .num{ font-weight:800; color:var(--steel); font-size:14px; flex:none; width:26px; }
.philosophy-list h3{ font-size:15.5px; margin-bottom:6px; }
.philosophy-list p{ font-size:14px; color:var(--ink-soft); }

.profile-table{ width:100%; border-collapse:collapse; font-size:14.5px; }
.profile-table tr{ border-top:1px solid var(--line); }
.profile-table tr:first-child{ border-top:none; }
.profile-table th,.profile-table td{ text-align:left; padding:13px 0; vertical-align:top; }
.profile-table th{ width:190px; color:var(--ink-soft); font-weight:600; }
.profile-table td{ color:var(--navy); font-weight:600; }
.placeholder-val{ color:#9aa6ad; font-weight:500; font-style:italic; }

/* CTA band */
.cta-band{ background:var(--navy); color:#fff; text-align:center; padding:68px 0; }
.cta-band h2{ color:#fff; font-size:28px; margin-bottom:12px; }
.cta-band .lede{ color:#c7d3dc; max-width:560px; margin:0 auto 28px; font-size:15.5px; }

/* ---------- Contact ---------- */
.contact-grid{ display:grid; grid-template-columns: 1fr 1.2fr; gap:48px; }
.contact-info dl{ margin-top:6px; }
.contact-info dt{ font-size:12px; text-transform:uppercase; letter-spacing:.06em; color:var(--ink-soft); margin-top:20px; }
.contact-info dt:first-child{ margin-top:0; }
.contact-info dd{ margin:4px 0 0; font-size:15.5px; font-weight:600; color:var(--navy); }
.contact-info dd.muted{ color:#9aa6ad; font-weight:500; font-style:italic; font-size:14px; }

.form-grid{ display:grid; grid-template-columns:1fr 1fr; gap:18px; }
.field{ margin-bottom:18px; }
.field.full{ grid-column: 1 / -1; }
.field label{ display:block; font-size:13px; font-weight:700; color:var(--navy); margin-bottom:7px; }
.field input, .field select, .field textarea{
  width:100%; border:1px solid var(--line); border-radius:var(--radius);
  padding:11px 13px; font-size:14.5px; font-family:inherit; color:var(--ink); background:#fff;
}
.field textarea{ resize:vertical; min-height:120px; }
.field input:focus, .field select:focus, .field textarea:focus{
  outline:none; border-color: var(--steel);
}
.field .hint{ font-size:12px; color:#9aa6ad; margin-top:6px; }
.checkbox-grid{ display:grid; grid-template-columns:repeat(2,1fr); gap:10px 16px; }
.checkbox-grid label{ display:flex; align-items:center; gap:9px; font-size:13.5px; font-weight:500; color:var(--ink-soft); }
.checkbox-grid input{ width:auto; }
.form-note{
  margin-top:20px; font-size:12.5px; color:var(--ink-soft); padding:14px 16px;
  background:var(--paper-alt); border-radius:var(--radius);
}
.form-status{ margin-top:14px; font-size:13.5px; font-weight:600; display:none; }
.form-status.is-visible{ display:block; }

/* ---------- Footer ---------- */
.site-footer{ background:var(--navy); color:#aebdc9; padding:56px 0 26px; margin-top:0; }
.footer-grid{ display:grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap:36px; padding-bottom:40px; border-bottom:1px solid rgba(255,255,255,.12); }
.footer-brand .name{ color:#fff; font-size:18px; font-weight:800; margin-bottom:10px; }
.footer-brand p{ font-size:13.5px; color:#9fb1bd; max-width:280px; }
.footer-col h4{ color:#fff; font-size:13px; letter-spacing:.05em; text-transform:uppercase; margin-bottom:16px; }
.footer-col li{ margin-bottom:10px; font-size:13.5px; }
.footer-col a:hover{ color:#fff; }
.footer-bottom{ display:flex; justify-content:space-between; align-items:center; padding-top:22px; font-size:12.5px; color:#7e93a1; flex-wrap:wrap; gap:10px; }

/* ---------- Reveal-on-scroll (subtle, progressive enhancement) ----------
   Content is visible by default (never depends on JS running or the
   element having scrolled into view). Only elements that are still
   off-screen at load get a brief pre-reveal dim, so nothing can end up
   permanently hidden if JS fails, a crawler doesn't scroll, or the
   IntersectionObserver never fires for an element. */
.reveal{ opacity:1; transform:none; }
.js-reveal-ready .reveal:not(.is-visible){ opacity:0; transform:translateY(14px); }
.reveal.is-visible{ opacity:1; transform:none; transition:opacity .5s ease, transform .5s ease; }
@media (prefers-reduced-motion: reduce){
  .js-reveal-ready .reveal:not(.is-visible){ opacity:1; transform:none; }
}

/* ---------- Responsive ---------- */
@media (max-width: 980px){
  .grid-3, .grid-4{ grid-template-columns: repeat(2,1fr); }
  .process{ grid-template-columns: repeat(2,1fr); row-gap:28px; }
  .footer-grid{ grid-template-columns: repeat(2,1fr); row-gap:28px; }
}

@media (max-width: 760px){
  .main-nav{ display:none; }
  .nav-toggle{ display:block; }
  .site-header.is-open .main-nav{
    display:flex; position:absolute; top:100%; left:0; right:0;
    background:#fff; border-bottom:1px solid var(--line); flex-direction:column;
    padding:18px var(--gutter) 22px; gap:18px;
  }
  .site-header.is-open .main-nav ul{ flex-direction:column; gap:16px; }
  .site-header.is-open .main-nav .nav-cta{ align-self:flex-start; }

  .hero{ padding:56px 0 48px; }
  .hero h1{ font-size:30px; }
  .page-hero h1{ font-size:26px; }
  section{ padding:52px 0; }
  .grid-2, .grid-3, .grid-4{ grid-template-columns: 1fr; }
  .process{ grid-template-columns: 1fr; }
  .app-grid{ grid-template-columns: 1fr; }
  .case-card, .partner-card{ grid-template-columns: 1fr; }
  .contact-grid{ grid-template-columns: 1fr; }
  .form-grid{ grid-template-columns: 1fr; }
  .checkbox-grid{ grid-template-columns: 1fr; }
  .footer-grid{ grid-template-columns: 1fr; }
  .footer-bottom{ flex-direction:column; align-items:flex-start; }
}

/* ---------- V4.1 visual system ---------- */
.brand-logo{ width:34px !important; height:34px !important; object-fit:contain; background:#fff; border-radius:2px; }
.hero-grid{ display:grid; grid-template-columns:minmax(0,1.05fr) minmax(360px,.95fr); gap:52px; align-items:center; }
.hero-visual{ border:1px solid rgba(255,255,255,.16); background:#0b1d2c; box-shadow:0 18px 45px rgba(0,0,0,.18); }
.hero-visual img{ width:100%; height:auto; }
.visual-strip{ display:grid; grid-template-columns:repeat(3,1fr); gap:22px; }
.visual-tile{ background:#fff; border:1px solid var(--line); }
.visual-tile img{ width:100%; aspect-ratio:5/3; object-fit:cover; }
.visual-tile h3{ padding:14px 18px 18px; font-size:15px; }
.privacy-content{ max-width:860px; }
.privacy-block{ padding:0 0 30px; margin-bottom:30px; border-bottom:1px solid var(--line-soft); }
.privacy-block:last-child{ border-bottom:0; }
.privacy-block h2{ font-size:20px; margin-bottom:10px; }
.privacy-block p{ color:var(--ink-soft); font-size:14.5px; }
@media (max-width: 900px){
  .hero-grid{ grid-template-columns:1fr; gap:34px; }
  .hero-visual{ max-width:720px; }
  .visual-strip{ grid-template-columns:1fr; }
  .main-nav{ gap:16px; }
  .main-nav ul{ gap:14px; }
}
@media (max-width: 760px){
  .main-nav{ display:none; position:absolute; left:0; right:0; top:100%; background:#fff; border-bottom:1px solid var(--line); padding:14px 24px 22px; flex-direction:column; align-items:stretch; box-shadow:0 12px 30px rgba(16,22,28,.08); }
  .main-nav.is-open{ display:flex; }
  .main-nav ul{ display:grid; grid-template-columns:repeat(2,1fr); gap:4px 18px; }
  .nav-cta{ justify-content:center; margin-top:10px; }
  .nav-toggle{ display:block; }
  .hero{ padding:64px 0 54px; }
  .hero h1{ font-size:34px; }
  .hero .lede{ font-size:16px; }
}