:root{
  --bg:#ffffff;
  --surface:#ffffff;
  --text:#1f2937;
  --muted:#6b7280;
  --line:#e5e7eb;
  --accent:#7aa7c7;
  --accent-soft:#e9f2f8;
  --shadow:0 6px 18px rgba(17,24,39,.08);
  --radius:14px;
  --container:980px;
  --header-h:72px;
}

*{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans JP", "Hiragino Sans", "Yu Gothic", sans-serif;
  color:var(--text);
  background:var(--bg);
  line-height:1.75;
  letter-spacing:.02em;
}
img{max-width:100%; height:auto; display:block;}
a{color:inherit; text-decoration-thickness: .08em; text-underline-offset: .2em;}
a:hover{color:var(--text);}

.container{max-width:var(--container); margin:0 auto; padding:0 18px;}

.skip-link{
  position:absolute;
  left:12px;
  top:10px;
  padding:10px 12px;
  background:var(--surface);
  border:1px solid var(--line);
  border-radius:10px;
  box-shadow:var(--shadow);
  transform:translateY(-140%);
  transition:transform .2s ease;
  z-index:1000;
}
.skip-link:focus{transform:translateY(0);}

.site-header{
  position:sticky;
  top:0;
  z-index:50;
  background:rgba(255,255,255,.92);
  backdrop-filter:saturate(140%) blur(8px);
  border-bottom:1px solid rgba(229,231,235,.8);
}
.header-inner{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
  padding:14px 0;
}
.brand{display:flex; flex-direction:column; gap:4px; min-width:220px;}
.brand-link{display:flex; align-items:center; gap:10px; text-decoration:none;}
.logo{width:40px; height:40px; border-radius:10px;}
.site-title{font-size:1.15rem; margin:0; line-height:1.2;}
.site-tagline{margin:0; color:var(--muted); font-size:.95rem;}

.site-nav{display:flex; align-items:center; gap:14px; flex-wrap:wrap; justify-content:flex-end;}
.site-nav a{
  text-decoration:none;
  padding:8px 10px;
  border-radius:999px;
  border:1px solid transparent;
  color:var(--text);
}
.site-nav a:hover{background:var(--accent-soft); border-color:#d7e7f3;}

.main{padding:22px 0 40px;}
.section{padding:28px 0;}
.section-title{margin:0; font-size:1.35rem; letter-spacing:.01em;}
.section-header{margin-bottom:14px;}

/* Anchor offset for sticky header */
#articles, #company, #contact{scroll-margin-top:calc(var(--header-h) + 16px);}

.grid{
  display:grid;
  grid-template-columns:1fr;
  gap:14px;
}

.card{
  background:var(--surface);
  border:1px solid rgba(229,231,235,.9);
  border-radius:var(--radius);
  box-shadow:var(--shadow);
  padding:16px;
}
.card-header{display:flex; flex-direction:column; gap:6px;}
.card-title{margin:0; font-size:1.1rem; line-height:1.35;}
.card-link{text-decoration:none;}
.card-link:hover{text-decoration:underline;}

.meta{display:flex; gap:10px; align-items:center; flex-wrap:wrap; color:var(--muted); font-size:.92rem;}
.tag{
  display:inline-flex;
  align-items:center;
  padding:2px 10px;
  border-radius:999px;
  background:var(--accent-soft);
  color:#2b5c78;
  border:1px solid #d7e7f3;
}
.excerpt{margin:10px 0 0; color:#374151;}
.card-footer{margin-top:12px;}
.readmore{
  display:inline-block;
  text-decoration:none;
  padding:8px 12px;
  border-radius:10px;
  border:1px solid var(--line);
  background:#fff;
}
.readmore:hover{background:var(--accent-soft); border-color:#d7e7f3;}

.dl{margin:0;}
.dl-row{
  display:grid;
  grid-template-columns:140px 1fr;
  gap:12px;
  padding:10px 0;
  border-top:1px solid rgba(229,231,235,.8);
}
.dl-row:first-child{border-top:none; padding-top:0;}
.dl-row dt{color:var(--muted);}
.dl-row dd{margin:0;}
.dl a{color:#1f4b66;}

.contact-layout{display:grid; grid-template-columns:1fr; gap:14px;}
.card-subtitle{margin:0 0 10px; font-size:1.05rem;}
.contact-lines{margin:0; display:flex; gap:10px; flex-wrap:wrap;}
.contact-line{
  display:inline-flex;
  align-items:center;
  padding:8px 12px;
  border:1px solid var(--line);
  border-radius:999px;
  text-decoration:none;
}
.contact-line:hover{background:var(--accent-soft); border-color:#d7e7f3;}

.form{display:grid; gap:12px;}
.field{display:grid; gap:6px;}
label{font-size:.95rem; color:var(--muted);}
input, textarea{
  width:100%;
  padding:12px 12px;
  border-radius:12px;
  border:1px solid var(--line);
  background:#fff;
  font-size:1rem;
  line-height:1.5;
  outline:none;
}
input:focus, textarea:focus{border-color:#c7dceb; box-shadow:0 0 0 4px rgba(122,167,199,.18);}

.actions{display:flex; align-items:flex-start; justify-content:space-between; gap:12px; flex-wrap:wrap;}
.button{
  appearance:none;
  border:1px solid #c7dceb;
  background:var(--accent-soft);
  color:#1f4b66;
  padding:10px 14px;
  border-radius:12px;
  font-weight:600;
  cursor:pointer;
}
.button:hover{filter:brightness(.98);}
.form-note{margin:0; color:var(--muted); font-size:.9rem;}

.site-footer{border-top:1px solid rgba(229,231,235,.9); padding:18px 0;}
.footer-inner{color:var(--muted);}

.back-to-top{
  position:fixed;
  right:16px;
  bottom:16px;
  padding:10px 12px;
  border-radius:999px;
  border:1px solid var(--line);
  background:#fff;
  box-shadow:var(--shadow);
  cursor:pointer;
  opacity:0;
  pointer-events:none;
  transform:translateY(6px);
  transition:opacity .2s ease, transform .2s ease;
}
.back-to-top.is-visible{opacity:1; pointer-events:auto; transform:translateY(0);}

@media (max-width:720px){
  :root{--header-h:92px;}
  .header-inner{flex-direction:column; align-items:flex-start;}
  .brand{min-width:auto;}
  .site-nav{justify-content:flex-start;}
  .dl-row{grid-template-columns:1fr; gap:4px;}
}