:root{
  --navy:#0F2C4C;
  --blue:#1B4F8C;
  --blue-mid:#2E6FB8;
  --blue-light:#6FA8E0;
  --sky:#EEF4FB;
  --sky-alt:#DEEAF7;
  --ink:#1B2733;
  --ink-soft:#54626E;
  --white:#FFFFFF;
  --line:#C7D9EC;
  --maxw:1180px;
}

*{box-sizing:border-box;}
html,body{width:100%;overflow-x:hidden;}
html{scroll-behavior:smooth;}
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto;}
  *{animation-duration:0.01ms !important; transition-duration:0.01ms !important;}
}

body{
  margin:0;
  background:var(--sky);
  color:var(--ink);
  font-family:"Noto Sans JP", sans-serif;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
}

h1,h2,h3,.disp{
  font-family:"Zen Kaku Gothic New", sans-serif;
  font-weight:900;
  letter-spacing:.02em;
  margin:0;
}
.mono{font-family:"Roboto Mono", monospace; letter-spacing:.03em;}
a{color:inherit;text-decoration:none;}
ul{list-style:none;margin:0;padding:0;}
img,svg{display:block;max-width:100%;}
button{font-family:inherit;}

.wrap{max-width:var(--maxw); margin:0 auto; padding:0 24px;}

section[id]{scroll-margin-top:76px;}

.blueprint-frame{position:relative;}
.blueprint-frame::before,
.blueprint-frame::after{
  content:""; position:absolute; width:20px; height:20px;
  border:2px solid var(--blue-mid); pointer-events:none;
}
.blueprint-frame::before{top:-10px; left:-10px; border-right:none; border-bottom:none;}
.blueprint-frame::after{bottom:-10px; right:-10px; border-left:none; border-top:none;}

/* ---------- header (transparent over hero, solid on scroll) ---------- */
header{
  position:fixed; top:0; left:0; right:0; z-index:200;
  background:linear-gradient(180deg, rgba(6,20,36,0.55) 0%, rgba(6,20,36,0.0) 100%);
  transition:background .3s ease, backdrop-filter .3s ease, border-color .3s ease;
  border-bottom:1px solid transparent;
}
header.is-scrolled{
  background:rgba(238,244,251,0.94);
  backdrop-filter:blur(6px);
  border-bottom:1px solid var(--line);
}
.header-inner{
  max-width:var(--maxw); margin:0 auto; padding:0 24px;
  height:68px; display:flex; align-items:center; justify-content:space-between; gap:12px;
}
.logo{display:flex; align-items:center; gap:10px; font-family:"Zen Kaku Gothic New", sans-serif; font-weight:900; font-size:1.05rem; min-width:0; color:var(--white); transition:color .3s ease;}
header.is-scrolled .logo{color:var(--ink);}
.logo-mark{
  height:42px;
  width:auto;
  flex:none;
  display:block;
}
.logo .name{white-space:nowrap;}
.logo small{display:block; font-family:"Noto Sans JP", sans-serif; font-weight:500; font-size:.6rem; color:#DCE7F4; letter-spacing:.08em; transition:color .3s ease;}
header.is-scrolled .logo small{color:var(--ink-soft);}

nav.primary-nav ul{display:flex; gap:26px;}
nav.primary-nav a{font-size:.85rem; font-weight:500; position:relative; padding:4px 0; color:var(--white); transition:color .3s ease;}
header.is-scrolled nav.primary-nav a{color:var(--ink);}
nav.primary-nav a::after{content:""; position:absolute; left:0; bottom:0; width:0%; height:2px; background:var(--blue-light); transition:width .25s ease;}
nav.primary-nav a:hover::after, nav.primary-nav a:focus-visible::after{width:100%;}

.tel-btn{
  display:flex; align-items:center; gap:8px;
  background:var(--blue); color:var(--white);
  padding:9px 14px; font-size:.8rem; font-weight:700; white-space:nowrap; flex:none;
}
.tel-btn:focus-visible, a:focus-visible, button:focus-visible{outline:3px solid var(--blue-light); outline-offset:2px;}

.burger{display:none; flex-direction:column; gap:5px; background:none; border:none; cursor:pointer; padding:8px; flex:none;}
.burger span{width:22px; height:2px; background:var(--white); display:block; transition:background .3s ease;}
header.is-scrolled .burger span{background:var(--ink);}

/* ---------- hero photo (header overlays this, transparent header on top) ---------- */
.hero-photo{
  position:relative;
  margin:0;
  padding:0;
  line-height:0;
  background:var(--navy);
}
.hero-photo img{
  width:100%;
  height:auto;
  display:block;
}
/* clickable areas over the 建築工事/電気工事/外壁工事 caption bar baked into the photo */
.hero-links{
  position:absolute;
  left:0; right:0;
  bottom:0;
  height:13.3%;
  display:flex;
}
.hero-links a{
  display:block;
  position:relative;
  outline-offset:-4px;
}
/* measured from the source photo's caption bar: columns are NOT equal thirds */
.hero-links a:nth-child(1){flex:0 0 38.3%;}
.hero-links a:nth-child(2){flex:0 0 22.7%;}
.hero-links a:nth-child(3){flex:0 0 39%;}
.hero-links a:hover,
.hero-links a:focus-visible{
  background:rgba(255,255,255,0.10);
}

.btn{display:inline-flex; align-items:center; gap:10px; padding:12px 22px; font-weight:700; font-size:.86rem; border:2px solid var(--white); transition:transform .18s ease, background .18s ease, color .18s ease;}
.btn-primary{background:var(--white); color:var(--navy);}
.btn-primary:hover{background:var(--blue-light); border-color:var(--blue-light); color:var(--navy); transform:translateY(-2px);}
.btn-ghost{background:transparent; color:var(--white);}
.btn-ghost:hover{background:var(--white); color:var(--navy); transform:translateY(-2px);}

/* ---------- section shell ---------- */
section{padding:76px 0; position:relative;}
.section-head{
  display:flex; align-items:flex-end; justify-content:space-between; gap:24px;
  margin-bottom:44px; padding-bottom:18px; border-bottom:1px dashed var(--line); flex-wrap:wrap;
}
.section-head .num{font-family:"Roboto Mono", monospace; font-size:.78rem; color:var(--blue); font-weight:700;}
.section-head h2{font-size:clamp(1.5rem, 3vw, 2.1rem); margin-top:6px;}
.section-head .desc{max-width:36ch; font-size:.88rem; color:var(--ink-soft); text-align:right;}
@media (max-width:720px){.section-head .desc{text-align:left;}}

.reveal{opacity:0; transform:translateY(16px); transition:opacity .6s ease, transform .6s ease;}
.reveal.is-visible{opacity:1; transform:translateY(0);}

/* ---------- services / features ---------- */
.services-alt{background:var(--sky-alt);}
.service-grid{display:grid; grid-template-columns:repeat(3,1fr); gap:22px;}
.service-card{background:var(--white); padding:30px 24px 26px; border-top:4px solid var(--blue); position:relative;}
.service-card .code{font-family:"Roboto Mono", monospace; font-size:.72rem; color:var(--blue); font-weight:700; background:var(--sky-alt); display:inline-block; padding:3px 8px; margin-bottom:18px;}
.icon{width:42px;height:42px; margin-bottom:16px; color:var(--navy);}
.service-card h3{font-size:1.08rem; margin-bottom:10px;}
.service-card p{font-size:.86rem; color:var(--ink-soft); margin:0;}

/* ---------- company overview ---------- */
.spec-sheet{border:1px solid var(--line); background:var(--white);}
.spec-row{display:grid; grid-template-columns:200px 1fr; border-bottom:1px dashed var(--line);}
.spec-row:last-child{border-bottom:none;}
.spec-row dt{font-family:"Roboto Mono", monospace; font-size:.76rem; font-weight:700; color:var(--blue); padding:20px 22px; border-right:1px dashed var(--line); background:var(--sky-alt);}
.spec-row dd{margin:0; padding:20px 22px; font-size:.92rem;}
.spec-row dd .post{color:var(--ink-soft); font-size:.8rem; display:block; margin-bottom:4px; font-family:"Roboto Mono", monospace;}
@media (max-width:640px){
  .spec-row{grid-template-columns:1fr;}
  .spec-row dt{border-right:none; border-bottom:1px dashed var(--line);}
}

/* ---------- contact ---------- */
.contact-wrap{display:grid; grid-template-columns:0.9fr 1.1fr; background:var(--navy); color:var(--white);}
.contact-info{padding:48px 36px;}
.contact-info h2{color:var(--white); font-size:clamp(1.4rem,3vw,1.9rem);}
.contact-info p{color:#C9D8E8; font-size:.9rem; margin-top:16px; max-width:38ch;}
.contact-info .tel-big{margin-top:28px; display:flex; align-items:center; gap:12px;}
.contact-info .tel-big .num{font-family:"Roboto Mono", monospace; font-size:1.35rem; font-weight:700; color:var(--blue-light);}
.contact-form{padding:48px 36px; background:var(--blue);}
.field{margin-bottom:18px;}
.field label{display:block; font-size:.76rem; font-weight:700; margin-bottom:8px; color:#DCE7F4; font-family:"Roboto Mono", monospace;}
.field input, .field textarea{width:100%; padding:12px 13px; background:rgba(255,255,255,0.08); border:1px solid rgba(255,255,255,0.32); color:var(--white); font-family:"Noto Sans JP", sans-serif; font-size:.9rem;}
.field input::placeholder, .field textarea::placeholder{color:#B9CDE3;}
.field textarea{resize:vertical; min-height:100px;}
.submit-row{display:flex; align-items:center; gap:16px; margin-top:6px; flex-wrap:wrap;}
.btn-submit{background:var(--white); color:var(--navy); border:none; padding:13px 28px; font-weight:700; font-size:.9rem; cursor:pointer; transition:transform .18s ease;}
.btn-submit:hover{transform:translateY(-2px); background:var(--blue-light);}
.form-note{font-size:.74rem; color:#BFD3E8;}
.form-status{font-size:.8rem; color:var(--blue-light); display:none;}

/* ---------- footer ---------- */
footer{background:var(--navy); color:#9FB4C9; padding:30px 0; border-top:1px solid rgba(255,255,255,0.1);}
.footer-inner{display:flex; justify-content:space-between; align-items:center; flex-wrap:wrap; gap:10px; font-size:.76rem;}

/* ---------- responsive ---------- */
@media (max-width:960px){
  .service-grid{grid-template-columns:1fr;}
  .contact-wrap{grid-template-columns:1fr;}
}
@media (max-width:760px){
  .logo .name .full{display:none;}
  .logo-mark{height:34px;}
  nav.primary-nav{
    position:fixed; top:68px; left:0; right:0;
    background:var(--sky); border-bottom:1px solid var(--line);
    max-height:0; overflow:hidden;
    transition:max-height .28s ease;
  }
  nav.primary-nav.open{max-height:320px;}
  nav.primary-nav ul{flex-direction:column; padding:6px 24px 18px; gap:0;}
  nav.primary-nav li{border-bottom:1px solid var(--line);}
  nav.primary-nav a{display:block; padding:14px 0; color:var(--ink) !important;}
  .burger{display:flex;}
  .tel-btn span.txt{display:none;}
  section{padding:52px 0;}
}