:root {
  color-scheme: dark;
  --bg: #080a12;
  --panel: rgba(18, 22, 38, 0.82);
  --panel-strong: #151a2b;
  --text: #f6f7fb;
  --muted: #a9aec2;
  --line: rgba(255, 255, 255, 0.11);
  --accent: #ff6f91;
  --accent-2: #75d9ff;
  --ok: #7ee2b8;
  --warning: #ffd27a;
  font-family: Inter, "Noto Sans JP", "Hiragino Kaku Gothic ProN", Meiryo, system-ui, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at 15% 5%, rgba(255, 111, 145, 0.14), transparent 28rem),
    radial-gradient(circle at 88% 16%, rgba(117, 217, 255, 0.12), transparent 30rem),
    var(--bg);
  line-height: 1.7;
}

a { color: inherit; }

.shell { width: min(1120px, calc(100% - 32px)); margin-inline: auto; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--line);
  background: rgba(8, 10, 18, 0.84);
  backdrop-filter: blur(18px);
}

.nav {
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  font-weight: 800;
  text-decoration: none;
  letter-spacing: -0.02em;
}

.brand img { width: 36px; height: 36px; border-radius: 10px; }

.nav-links { display: flex; align-items: center; gap: 20px; }
.nav-links a { color: var(--muted); font-size: 0.92rem; text-decoration: none; }
.nav-links a:hover, .nav-links a:focus-visible { color: var(--text); }

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(310px, 0.85fr);
  align-items: center;
  gap: 52px;
  min-height: 610px;
  padding-block: 88px 72px;
}

.eyebrow {
  margin: 0 0 16px;
  color: var(--accent-2);
  font-weight: 800;
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

h1, h2, h3 { line-height: 1.22; letter-spacing: -0.035em; }
h1 { margin: 0; font-size: clamp(2.7rem, 7vw, 5.6rem); }
h2 { margin: 0 0 14px; font-size: clamp(1.8rem, 4vw, 2.7rem); }
h3 { margin: 0 0 8px; font-size: 1.2rem; }

.lead {
  max-width: 690px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: clamp(1.02rem, 2vw, 1.22rem);
}

.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 19px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--panel-strong);
  font-weight: 750;
  text-decoration: none;
}

.button.primary {
  border-color: transparent;
  color: #171019;
  background: linear-gradient(135deg, #ff91aa, #ffd0dc);
  box-shadow: 0 12px 35px rgba(255, 111, 145, 0.18);
}

.button:hover { transform: translateY(-1px); filter: brightness(1.07); }
.button:focus-visible { outline: 3px solid rgba(117, 217, 255, 0.5); outline-offset: 2px; }

.wall-visual {
  position: relative;
  min-height: 340px;
  perspective: 900px;
}

.screen {
  position: absolute;
  width: 68%;
  aspect-ratio: 16 / 10;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 18px;
  background:
    linear-gradient(140deg, rgba(117, 217, 255, 0.12), rgba(255, 111, 145, 0.18)),
    #12172a;
  box-shadow: inset 0 0 35px rgba(255, 255, 255, 0.04), 0 28px 70px rgba(0, 0, 0, 0.42);
}

.screen::after {
  content: "";
  position: absolute;
  inset: 17px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 11px;
  background: linear-gradient(135deg, rgba(255,255,255,.03), transparent 55%);
}

.screen.one { left: 0; top: 76px; transform: rotateY(27deg) rotateZ(-2deg); }
.screen.two { right: 0; top: 22px; transform: rotateY(-23deg) rotateZ(2deg); }
.screen.three { left: 19%; bottom: 0; transform: translateZ(80px); }

.section { padding-block: 72px; }
.section + .section { border-top: 1px solid var(--line); }
.section-intro { max-width: 720px; margin: 0 0 28px; color: var(--muted); }

.grid { display: grid; gap: 16px; }
.grid.three { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid.four { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.card {
  display: block;
  min-height: 100%;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--panel);
  text-decoration: none;
  box-shadow: 0 18px 45px rgba(0, 0, 0, 0.16);
}

a.card:hover, a.card:focus-visible { border-color: rgba(117, 217, 255, 0.5); transform: translateY(-2px); }
.card p { margin: 0; color: var(--muted); }
.card .tag { display: block; margin-bottom: 9px; color: var(--accent-2); font-size: 0.76rem; font-weight: 800; letter-spacing: 0.08em; text-transform: uppercase; }

.callout {
  padding: 24px 26px;
  border: 1px solid rgba(126, 226, 184, 0.25);
  border-radius: 18px;
  background: rgba(126, 226, 184, 0.07);
}
.callout.warning { border-color: rgba(255, 210, 122, 0.3); background: rgba(255, 210, 122, 0.07); }
.callout p:last-child { margin-bottom: 0; }

.article { width: min(860px, calc(100% - 32px)); margin: 0 auto; padding: 72px 0 100px; }
.article h1 { font-size: clamp(2.25rem, 6vw, 4.2rem); }
.article h2 { margin-top: 58px; padding-top: 18px; border-top: 1px solid var(--line); }
.article h3 { margin-top: 30px; }
.article p, .article li { color: #d7d9e3; }
.article table { width: 100%; border-collapse: collapse; margin: 24px 0; }
.article th, .article td { padding: 12px 14px; border: 1px solid var(--line); text-align: left; vertical-align: top; }
.article th { background: var(--panel-strong); }
.article code { padding: 0.12em 0.38em; border-radius: 5px; background: #20263b; }
.article .back { display: inline-block; margin-bottom: 30px; color: var(--muted); }

.site-footer { border-top: 1px solid var(--line); padding-block: 32px; color: var(--muted); font-size: 0.88rem; }
.footer-row { display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.footer-row p { margin: 0; }
.footer-row a { margin-right: 14px; }

@media (max-width: 860px) {
  .hero { grid-template-columns: 1fr; min-height: auto; padding-top: 64px; }
  .wall-visual { min-height: 300px; order: -1; }
  .grid.three, .grid.four { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 600px) {
  .nav-links a:not(.language) { display: none; }
  .hero { gap: 28px; padding-block: 44px 56px; }
  .wall-visual { min-height: 225px; }
  .grid.three, .grid.four { grid-template-columns: 1fr; }
  .section { padding-block: 52px; }
  .button { width: 100%; }
  .article { padding-top: 48px; }
  .article table { display: block; overflow-x: auto; }
}

@media (prefers-reduced-motion: no-preference) {
  .button, .card { transition: transform 160ms ease, filter 160ms ease, border-color 160ms ease; }
}