:root {
  color-scheme: light;
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans CJK JP", Meiryo, sans-serif;
  color: #1b2441;
  background: #f7f9fb;
  line-height: 1.7;
}

* { box-sizing: border-box; }
body { margin: 0; }
h1, h2, p { margin: 0; }
a { color: #185286; }
a:focus-visible, summary:focus-visible {
  outline: 3px solid #087879;
  outline-offset: 4px;
}

.wrap { width: min(100% - 2rem, 62rem); margin-inline: auto; }
.site-header { background: #fff; border-bottom: 1px solid #d9e1e9; }
.header-inner {
  display: flex;
  min-height: 4rem;
  align-items: center;
  justify-content: space-between;
  gap: .75rem;
}
.brand { display: inline-flex; align-items: center; gap: .6rem; font-weight: 750; }
.brand img { display: block; }
.header-link { padding: .6rem 0 .6rem .4rem; text-underline-offset: .2em; }

.intro { padding: clamp(2.5rem, 7vw, 5rem) 0 2rem; }
h1 { font-size: clamp(1.8rem, 4.7vw, 3.25rem); line-height: 1.2; letter-spacing: .01em; }
.intro p { max-width: 40rem; margin-top: 1rem; color: #495572; }
.support-grid {
  display: grid;
  grid-template-columns: 20rem minmax(0, 1fr);
  align-items: start;
  gap: clamp(1rem, 3vw, 2rem);
}
.contact, .guide { padding: clamp(1rem, 3vw, 1.75rem); border: 1px solid #d9e1e9; border-radius: 1.15rem; background: #fff; }
.contact { border-top: 4px solid #087879; scroll-margin-top: 1rem; }
h2 { margin-bottom: .75rem; font-size: 1.2rem; line-height: 1.4; }
.contact p, details p { color: #495572; }
.email-button {
  display: block;
  margin-block: 1.25rem 1rem;
  padding: .75rem .9rem;
  border-radius: .7rem;
  background: #1b345d;
  color: #fff;
  text-decoration: none;
  font-weight: 700;
}
.email-button:hover { background: #254773; }
.address { display: block; font-size: .9rem; font-weight: 500; overflow-wrap: anywhere; }
.small { font-size: .875rem; }
details + details { border-top: 1px solid #d9e1e9; }
summary { cursor: pointer; padding-block: .75rem; color: #203a61; font-weight: 700; }
details p { padding: 0 .2rem 1rem; }
.site-footer { margin-block: 2.75rem 1.5rem; padding-top: 1rem; border-top: 1px solid #d9e1e9; color: #495572; font-size: .9rem; }

@media (max-width: 44rem) {
  .support-grid { grid-template-columns: minmax(0, 1fr); }
}