:root {
  color-scheme: light;
  --ink: #17212b;
  --muted: #5f707c;
  --line: #dce4e8;
  --bg: #f5f7f8;
  --panel: #ffffff;
  --accent: #087f9c;
  --accent-soft: #e8f4f6;
  --shadow: 0 16px 40px rgba(24, 45, 61, 0.09);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans", "Noto Sans JP", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--bg); }
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
h1, h2, h3, p { margin-top: 0; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 72px;
  padding: 12px clamp(20px, 6vw, 92px);
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid var(--line);
  box-shadow: 0 4px 18px rgba(24, 45, 61, 0.07);
  backdrop-filter: blur(16px);
}

.brand img { width: 170px; }
.header-links { display: flex; flex-wrap: wrap; gap: 18px; color: #43535e; font-size: 13px; font-weight: 800; }
.header-links a:hover { color: var(--accent); }

.detail-hero {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(340px, 1.1fr);
  gap: clamp(32px, 7vw, 100px);
  align-items: center;
  padding: clamp(60px, 9vw, 120px) clamp(20px, 8vw, 128px);
  background: var(--accent-soft);
}

.detail-hero-copy { max-width: 620px; }
.eyebrow { margin-bottom: 12px; color: var(--accent); font-size: 12px; font-weight: 900; letter-spacing: .12em; text-transform: uppercase; }
.detail-hero h1 { margin-bottom: 22px; font-size: clamp(46px, 5.4vw, 76px); line-height: .98; letter-spacing: -.06em; text-wrap: balance; }
.detail-lead { color: #425660; font-size: clamp(18px, 2vw, 25px); font-weight: 600; line-height: 1.75; }
.detail-icon { width: min(260px, 60%); margin-bottom: 24px; }
.detail-hero-visual { display: grid; place-items: center; min-height: 360px; margin: 0; padding: 38px; background: #fff; border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow); }
.detail-hero-visual img { width: min(280px, 72%); }

.button-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: 0 20px; border: 1px solid var(--line); border-radius: 4px; font-weight: 900; }
.button-primary { color: #fff; background: var(--accent); border-color: var(--accent); }
.button-secondary { background: #fff; }

.section { padding: clamp(48px, 6.5vw, 84px) clamp(20px, 8vw, 128px); }
#features { padding-inline: clamp(20px, 6vw, 96px); }
#features .section-heading { width: min(100%, 960px); max-width: none; margin-right: auto; margin-left: auto; }
.section-heading { max-width: 780px; margin-bottom: 32px; }
.section-heading h2 { margin-bottom: 16px; font-size: clamp(30px, 3.8vw, 52px); letter-spacing: -.04em; text-wrap: balance; }
.section-heading p:not(.eyebrow) { color: var(--muted); font-size: 17px; line-height: 1.8; }
.feature-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.feature-grid--screens { width: min(100%, 1120px); margin-right: auto; margin-left: auto; gap: 32px; align-items: start; }
.feature-grid--screen-summary { width: min(100%, 1120px); margin: 24px auto 0; }
.feature-card { padding: 28px; background: var(--panel); border: 1px solid var(--line); border-radius: 8px; box-shadow: none; }
.feature-card .feature-image { display: block; width: 100%; height: auto; object-fit: contain; background: #0d151b; }
.feature-card h3 { margin-bottom: 10px; font-size: 22px; }
.feature-card p { margin-bottom: 0; color: var(--muted); line-height: 1.75; }
.feature-card--visual {
  width: 100%;
  overflow: hidden;
  padding: 0;
  border-radius: 12px;
  box-shadow: 0 12px 30px rgba(24, 45, 61, 0.08);
}
.feature-card--primary {
  grid-column: 1 / -1;
  justify-self: center;
  width: min(100%, 920px);
}
.feature-grid--screens > .feature-card--visual:last-child:not(.feature-card--primary) {
  grid-column: 1 / -1;
  justify-self: center;
  width: calc((100% - 32px) / 2);
}
.screen-card:focus-visible { outline: 4px solid #f0a020; outline-offset: 4px; }
.feature-card-copy { padding: 24px 26px 28px; }
.feature-guide-label {
  margin-bottom: 8px !important;
  color: var(--accent) !important;
  font-size: 11px;
  font-weight: 900;
  letter-spacing: .08em;
}
.feature-card--visual h3 {
  margin-bottom: 16px;
  font-size: clamp(21px, 2vw, 27px);
  line-height: 1.35;
}
.feature-point-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.feature-point-list li {
  position: relative;
  min-width: 0;
  padding: 0 0 0 17px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.65;
}
.feature-point-list li::before {
  position: absolute;
  top: .58em;
  left: 0;
  width: 7px;
  height: 7px;
  background: var(--accent);
  border-radius: 50%;
  content: "";
}
.feature-point-list strong {
  display: block;
  margin-bottom: 2px;
  color: var(--ink);
  font-size: 15px;
}
.feature-card-note {
  margin-top: 16px !important;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 14px;
}

.screen-section { background: #fff; }
.screen-card { display: block; width: min(100%, 1100px); overflow: hidden; background: #f0f4f6; border: 1px solid var(--line); border-radius: 12px; cursor: zoom-in; }
.screen-card img { width: 100%; height: auto; }
.screen-caption { padding: 18px 22px; color: var(--ink); background: #eef4f6; font-size: 16px; font-weight: 800; line-height: 1.7; }
.developer-note-section { background: #f7f9fa; }
.developer-note-heading {
  max-width: 980px;
  margin-right: auto;
  margin-left: auto;
  padding-bottom: 26px;
  border-bottom: 1px solid var(--line);
}
.developer-note-heading h2 { max-width: 920px; line-height: 1.16; }
.developer-note-meta { display: flex; flex-wrap: wrap; gap: 8px 20px; margin-top: 22px; color: #61717c; font-size: 13px; font-weight: 800; }
.developer-note-meta > * + * { padding-left: 20px; border-left: 1px solid #cbd5da; }
.developer-note-card {
  display: grid;
  grid-template-columns: minmax(280px, .68fr) minmax(0, 1.32fr);
  gap: clamp(30px, 4vw, 56px);
  align-items: start;
  max-width: 980px;
  margin: 0 auto;
  padding: 36px 0 44px;
  background: transparent;
  border-top: 4px solid var(--accent);
  border-bottom: 1px solid var(--line);
}
.developer-note-photo { align-self: start; display: flex; flex-direction: column; width: min(100%, 320px); margin: 0; background: transparent; }
.developer-note-photo a { display: block; }
.developer-note-photo img { display: block; width: 100%; height: auto; aspect-ratio: 4 / 3; object-fit: cover; }
.developer-note-photo figcaption { padding: 12px 0 0; color: var(--muted); background: transparent; border-top: 1px solid var(--line); font-size: 12px; line-height: 1.7; }
.developer-note-copy { padding: 0; }
.developer-note-date { margin-bottom: 12px; color: var(--accent); font-size: 12px; font-weight: 900; letter-spacing: .08em; }
.developer-note-copy h3 { margin-bottom: 18px; font-size: clamp(25px, 3vw, 36px); line-height: 1.35; letter-spacing: -.03em; }
.developer-note-copy > p { color: var(--muted); font-size: 16px; line-height: 1.95; }
.developer-note-copy > .developer-note-lead { margin-bottom: 28px; padding-left: 18px; color: var(--ink); border-left: 4px solid var(--accent); font-size: 18px; font-weight: 750; line-height: 1.9; }
.dm3-routing-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; margin: 28px 0; }
.dm3-routing-grid div { padding: 16px; background: #f5f8f9; border: 1px solid var(--line); border-radius: 6px; }
.dm3-routing-grid dt { margin-bottom: 7px; color: var(--accent); font-size: 10px; font-weight: 900; letter-spacing: .1em; }
.dm3-routing-grid dd { margin: 0; font-size: 15px; font-weight: 800; line-height: 1.55; }
.cable-notice { margin-top: 34px; padding: 28px 0 0; background: transparent; border-top: 1px solid #aebcc3; }
.cable-notice h4 { margin: 0 0 12px; color: var(--ink); font-size: 20px; line-height: 1.45; }
.cable-notice p { margin: 0; color: #455761; font-size: 14px; line-height: 1.9; }
.cable-notice p + p { margin-top: 12px; }
.cable-notice .notice-subheading { margin-top: 30px; padding-top: 24px; border-top: 1px solid var(--line); }
.official-source-links { display: flex; flex-wrap: wrap; gap: 4px 8px; }
.official-source-links a { color: var(--accent); font-weight: 800; text-decoration: underline; text-underline-offset: 3px; }
.field-test-note { margin: 20px 0 0; font-size: 12px; line-height: 1.75; }
.spec-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; }
.spec { padding: 22px; background: #fff; border: 1px solid var(--line); border-radius: 8px; }
.spec span { display: block; margin-bottom: 8px; color: var(--muted); font-size: 11px; font-weight: 900; letter-spacing: .1em; }
.spec strong { font-size: 20px; }

.detail-footer { display: flex; justify-content: space-between; gap: 20px; padding: 28px clamp(20px, 8vw, 128px); color: var(--muted); background: #eef2f4; border-top: 1px solid var(--line); font-size: 13px; }
.detail-footer a { color: var(--accent); font-weight: 800; }

@media (max-width: 1100px) {
  .detail-hero {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .detail-hero-copy {
    max-width: 760px;
  }

  .detail-hero-visual {
    width: min(100%, 760px);
  }
}

@media (max-width: 820px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
    padding: 10px clamp(16px, 5vw, 36px);
  }
  .brand img { width: 148px; }
  .header-links {
    width: 100%;
    flex-wrap: nowrap;
    gap: 16px;
    overflow-x: auto;
    padding-bottom: 3px;
    scrollbar-width: thin;
  }
  .header-links a { flex: 0 0 auto; white-space: nowrap; }
  .detail-hero-visual { min-height: 260px; }
  .feature-grid, .spec-grid, .developer-note-card { grid-template-columns: 1fr; }
  .feature-grid--screens { width: min(100%, 640px); gap: 24px; }
  .feature-card--primary,
  .feature-grid--screens > .feature-card--visual:last-child:not(.feature-card--primary) { grid-column: auto; width: 100%; }
  .feature-point-list { grid-template-columns: 1fr; }
  .developer-note-card { gap: 30px; padding-top: 30px; }
  .developer-note-photo { width: min(100%, 340px); margin: 0 auto; }
  .developer-note-photo a { flex: none; }
  .developer-note-photo img { min-height: 0; aspect-ratio: 4 / 3; }
}

@media (max-width: 560px) {
  .brand img { width: 132px; }
  .header-links { gap: 14px; font-size: 12px; }
  .detail-hero { gap: 28px; padding-top: 44px; padding-bottom: 44px; }
  .detail-hero h1 { font-size: clamp(40px, 12vw, 52px); }
  .section { padding-top: 42px; padding-bottom: 42px; }
  .section-heading { margin-bottom: 26px; }
  .developer-note-meta { display: grid; gap: 4px; }
  .developer-note-meta > * + * { padding-left: 0; border-left: 0; }
  .dm3-routing-grid { grid-template-columns: 1fr; }
  .button { width: 100%; }
  #features { padding-right: 16px; padding-left: 16px; }
  .feature-card-copy { padding: 20px 20px 24px; }
  .detail-footer { flex-direction: column; }
}