:root {
  --bg: #070b14;
  --bg-raise: rgba(12, 22, 40, 0.88);
  --ink: #e8eef8;
  --muted: #93a4bc;
  --line: rgba(130, 176, 220, 0.18);
  --cyan: #5ad8ff;
  --blue: #3b82f6;
  --max: 1100px;
  --sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --mono: "Cascadia Mono", "Sarasa Mono SC", Consolas, "Courier New", monospace;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  background:
    radial-gradient(900px 420px at 85% -10%, rgba(59, 130, 246, 0.22), transparent 60%),
    radial-gradient(700px 380px at -10% 20%, rgba(90, 216, 255, 0.08), transparent 55%),
    var(--bg);
  background-attachment: fixed;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(120, 170, 220, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(120, 170, 220, 0.045) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(circle at 50% 20%, #000 20%, transparent 80%);
}

a {
  color: inherit;
}

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.wrap {
  width: min(var(--max), calc(100% - 40px));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(7, 11, 20, 0.82);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line);
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 76px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  text-decoration: none;
}

.logo {
  flex: none;
  width: 42px;
  height: 42px;
  display: block;
  filter: drop-shadow(0 0 10px rgba(90, 216, 255, 0.35));
}

.brand-name {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.brand-name strong {
  font-size: 15px;
  font-weight: 650;
  letter-spacing: 0.02em;
}

.brand-name small {
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.03em;
}

.nav {
  display: flex;
  gap: 8px;
  flex: none;
}

.nav a {
  text-decoration: none;
  color: var(--muted);
  font-size: 14px;
  padding: 8px 12px;
  border-radius: 999px;
}

.nav a:hover {
  color: var(--ink);
  background: rgba(90, 216, 255, 0.08);
}

.hero {
  padding: 72px 0 36px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.75fr;
  gap: 48px;
  align-items: center;
}

.kicker {
  margin: 0 0 16px;
  color: var(--cyan);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.16em;
}

h1,
h2,
h3 {
  font-weight: 650;
  letter-spacing: 0.02em;
}

h1 {
  margin: 0;
  font-size: clamp(34px, 4.6vw, 52px);
  line-height: 1.2;
}

.lede {
  max-width: 38em;
  margin: 18px 0 0;
  color: #c5d2e4;
  font-size: 17px;
}

.lede-en {
  max-width: 44em;
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  gap: 12px;
  margin-top: 28px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 10px;
  border: 1px solid transparent;
  background: linear-gradient(180deg, #7ae4ff, #3cb4e0);
  color: #06202c;
  text-decoration: none;
  font-weight: 650;
  letter-spacing: 0.04em;
}

.btn:hover {
  filter: brightness(1.06);
  color: #06202c;
}

.btn.ghost {
  background: transparent;
  color: var(--ink);
  border-color: rgba(90, 216, 255, 0.4);
}

.btn.ghost:hover {
  border-color: var(--cyan);
  color: var(--cyan);
  filter: none;
}

.hero-visual {
  position: relative;
  padding: 32px 28px 24px;
  border-radius: 20px;
  border: 1px solid rgba(120, 190, 255, 0.22);
  background:
    radial-gradient(420px 180px at 80% 0%, rgba(90, 216, 255, 0.16), transparent 55%),
    linear-gradient(180deg, rgba(14, 26, 46, 0.95), rgba(8, 14, 28, 0.92));
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.28);
  overflow: hidden;
}

.hero-visual .logo {
  width: 84px;
  height: 84px;
}

.visual-name {
  margin: 18px 0 0;
  font-size: 28px;
  font-weight: 650;
  letter-spacing: 0.18em;
}

.visual-en {
  margin: 0;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.2em;
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.chips li {
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: #d5e6f5;
  font-size: 13px;
  background: rgba(90, 216, 255, 0.05);
}

section {
  padding: 28px 0 72px;
  scroll-margin-top: 88px;
}

.section-head {
  margin-bottom: 22px;
}

.section-head h2 {
  margin: 0;
  font-size: 32px;
}

.about-grid {
  display: grid;
  grid-template-columns: 1.35fr 0.75fr;
  gap: 28px;
}

.prose,
.principles,
.service,
.contact-card {
  border: 1px solid var(--line);
  background: var(--bg-raise);
  border-radius: 16px;
}

.prose {
  padding: 28px 28px 12px;
}

.prose p {
  margin: 0 0 16px;
  color: #c9d5e6;
}

.principles {
  margin: 0;
  padding: 8px 22px;
  list-style: none;
}

.principles li {
  padding: 16px 0 16px 14px;
  border-bottom: 1px solid var(--line);
  border-left: 2px solid var(--cyan);
  margin-left: 0;
}

.principles li:last-child {
  border-bottom: 0;
}

.principles strong {
  display: block;
}

.principles span {
  color: var(--muted);
  font-size: 14px;
}

.service-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 16px;
}

.service {
  position: relative;
  grid-column: span 2;
  padding: 22px 22px 20px;
  overflow: hidden;
}

.service:nth-child(4),
.service:nth-child(5) {
  grid-column: span 3;
}

.service::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), transparent 80%);
}

.service .idx {
  color: var(--cyan);
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.14em;
}

.service h3 {
  margin: 10px 0 8px;
  font-size: 20px;
}

.service p {
  margin: 0;
  color: var(--muted);
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.contact-card {
  display: block;
  padding: 22px 24px;
  text-decoration: none;
}

.contact-card.wide {
  grid-column: 1 / -1;
}

.contact-card span {
  display: block;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.12em;
}

.contact-card strong {
  display: block;
  margin-top: 8px;
  font-size: 20px;
  font-weight: 650;
  line-height: 1.45;
}

a.contact-card:hover {
  border-color: rgba(90, 216, 255, 0.55);
}

a.contact-card:hover strong {
  color: var(--cyan);
}

.site-footer {
  border-top: 1px solid var(--line);
  padding: 28px 0 40px;
  color: var(--muted);
  font-size: 13px;
}

.site-footer .wrap {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  align-items: center;
}

.site-footer strong {
  color: var(--ink);
  font-weight: 650;
}

.site-footer a {
  color: var(--cyan);
  text-decoration: none;
}

@media (max-width: 860px) {
  .hero-grid,
  .about-grid,
  .contact-grid,
  .service-grid {
    display: block;
  }

  .service,
  .service:nth-child(4),
  .service:nth-child(5),
  .contact-card.wide {
    grid-column: auto;
  }

  .service + .service,
  .contact-card + .contact-card {
    margin-top: 16px;
  }

  .site-header .wrap {
    flex-wrap: wrap;
    padding: 12px 0;
  }

  .nav {
    width: 100%;
    padding-bottom: 8px;
  }

  .brand-name strong {
    font-size: 14px;
  }

  h1 {
    font-size: 34px;
  }

  .contact-card strong {
    font-size: 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}