:root {
  --bg: #0b1020;
  --bg-soft: #121933;
  --panel: rgba(18, 25, 51, 0.72);
  --panel-strong: rgba(20, 28, 58, 0.92);
  --panel-2: rgba(255,255,255,0.04);
  --text: #eef2ff;
  --muted: #a9b4d0;
  --line: rgba(255,255,255,0.1);
  --accent: #77b7ff;
  --accent-2: #8ef0d0;
  --ok: #9ef3bf;
  --warn: #ffd38a;
  --shadow: 0 18px 50px rgba(0,0,0,0.32);
  --radius: 22px;
  --radius-sm: 14px;
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Inter, "Hiragino Sans", "Noto Sans JP", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(119, 183, 255, 0.22), transparent 32%),
    radial-gradient(circle at top right, rgba(142, 240, 208, 0.16), transparent 28%),
    linear-gradient(180deg, #0a0f1f 0%, #090d19 100%);
  min-height: 100vh;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

p,
li,
span,
strong,
small,
a,
button {
  overflow-wrap: anywhere;
}

.container {
  width: min(calc(100% - 32px), var(--max));
  margin: 0 auto;
}

/* Header / Navigation */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(16px);
  background: rgba(9, 13, 25, 0.72);
  border-bottom: 1px solid var(--line);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 72px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  letter-spacing: 0.02em;
  min-width: 0;
}

.brand-mark {
  width: 38px;
  height: 38px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  box-shadow: 0 10px 30px rgba(119, 183, 255, 0.28);
  display: grid;
  place-items: center;
  color: #081222;
  font-weight: 900;
  flex-shrink: 0;
}

.brand span:last-child {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  min-width: 0;
}

.nav-links a,
.lang-btn {
  color: var(--muted);
  padding: 10px 14px;
  border-radius: 999px;
  transition: 0.18s ease;
  background: transparent;
  border: 1px solid transparent;
  cursor: pointer;
  font: inherit;
}

.nav-links a:hover,
.lang-btn:hover,
.lang-btn.active {
  color: var(--text);
  background: rgba(255,255,255,0.08);
  border-color: var(--line);
}

.lang-switch {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

/* Common Hero */

.hero {
  padding: 72px 0 42px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 24px;
  align-items: stretch;
}

.hero-main,
.hero-side,
.hero-card,
.side-card,
.card,
.page-card,
.faq-item,
.notice,
.toc-card,
.tip {
  background: var(--panel);
  border: 1px solid var(--line);
  backdrop-filter: blur(14px);
  box-shadow: var(--shadow);
}

.hero-main,
.hero-card {
  border-radius: 28px;
  padding: 36px;
  position: relative;
  overflow: hidden;
}

.hero-main::after {
  content: "";
  position: absolute;
  inset: auto -8% -32% auto;
  width: 280px;
  height: 280px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(119,183,255,0.22), transparent 68%);
  pointer-events: none;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(255,255,255,0.06);
  color: var(--accent-2);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

h1 {
  margin: 18px 0 16px;
  font-size: clamp(34px, 6vw, 64px);
  line-height: 1.02;
  letter-spacing: -0.04em;
}

.lead {
  margin: 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
  max-width: 62ch;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 0 18px;
  border-radius: 14px;
  border: 1px solid transparent;
  font-weight: 700;
  transition: 0.18s ease;
}

.btn.primary {
  background: linear-gradient(135deg, var(--accent), #5e95ff);
  color: #081222;
}

.btn.primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 12px 30px rgba(119,183,255,0.25);
}

.btn.secondary {
  background: rgba(255,255,255,0.05);
  border-color: var(--line);
  color: var(--text);
}

.btn.secondary:hover {
  background: rgba(255,255,255,0.08);
}

.hero-meta {
  margin-top: 24px;
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.tag {
  padding: 8px 12px;
  border-radius: 999px;
  border: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}

.hero-side {
  border-radius: 28px;
  padding: 22px;
  display: grid;
  gap: 14px;
  align-content: start;
}

.side-stack {
  display: grid;
  gap: 14px;
}

.side-card {
  border-radius: 22px;
  padding: 20px;
}

.side-card small {
  display: block;
  color: var(--muted);
  margin-bottom: 8px;
}

.side-card strong {
  display: block;
  font-size: 21px;
  line-height: 1.35;
}

.stat {
  padding: 18px;
  border-radius: 18px;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.06);
}

.stat small {
  display: block;
  color: var(--muted);
  margin-bottom: 8px;
  font-size: 13px;
}

.stat strong {
  display: block;
  font-size: 22px;
  line-height: 1.3;
}

/* Index sections */

.section {
  padding: 28px 0 72px;
}

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

.section-header h2 {
  margin: 0 0 10px;
  font-size: clamp(26px, 3vw, 40px);
  letter-spacing: -0.03em;
}

.section-header p {
  margin: 0;
  color: var(--muted);
  line-height: 1.75;
}

.portal-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.page-card {
  border-radius: var(--radius);
  padding: 24px;
  transition: 0.18s ease;
  min-height: 100%;
}

.page-card:hover {
  transform: translateY(-3px);
  border-color: rgba(119,183,255,0.35);
}

.page-card .icon {
  width: 46px;
  height: 46px;
  border-radius: 14px;
  background: rgba(119,183,255,0.12);
  border: 1px solid rgba(119,183,255,0.16);
  display: grid;
  place-items: center;
  font-size: 22px;
  margin-bottom: 16px;
}

.page-card h3 {
  margin: 0 0 10px;
  font-size: 22px;
}

.page-card p {
  margin: 0 0 18px;
  color: var(--muted);
  line-height: 1.75;
}

.linkline {
  color: var(--accent);
  font-weight: 700;
}

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.card {
  border-radius: var(--radius);
  padding: 24px;
}

.card h3 {
  margin: 0 0 14px;
  font-size: 21px;
}

.checklist,
.timeline,
.contact-list,
.feature-list,
.steps,
.bullet-list,
.field-list {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.steps,
.bullet-list,
.field-list {
  margin-top: 16px;
}

.checklist li,
.timeline li,
.contact-list li,
.feature-list li,
.steps li,
.bullet-list li,
.field-list li {
  padding: 14px 16px;
  border-radius: 14px;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.06);
  line-height: 1.7;
  color: var(--muted);
}

.checklist strong,
.timeline strong,
.contact-list strong,
.feature-list strong,
.steps strong,
.bullet-list strong,
.field-list strong {
  color: var(--text);
}

.contact-list a {
  color: var(--accent);
  font-weight: 700;
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
  transition: 0.18s ease;
}

.contact-list a:hover {
  color: var(--accent-2);
}

.docs-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.mini-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.mini-card,
.mini {
  padding: 16px;
  border-radius: 16px;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.06);
}

.mini-card strong,
.mini strong {
  display: block;
  margin-bottom: 8px;
}

.mini-card p,
.mini p {
  margin: 0;
  color: var(--muted);
  line-height: 1.65;
  font-size: 14px;
}

.notice {
  border-radius: var(--radius);
  padding: 22px;
  margin-top: 18px;
}

.notice strong {
  display: block;
  margin-bottom: 8px;
  font-size: 18px;
}

.notice p {
  margin: 0;
  color: var(--muted);
  line-height: 1.75;
}

.faq {
  display: grid;
  gap: 12px;
  margin-top: 16px;
}

.faq-item {
  border-radius: 18px;
  padding: 20px;
}

.faq-item h3 {
  margin: 0 0 8px;
  font-size: 18px;
}

.faq-item p {
  margin: 0;
  color: var(--muted);
  line-height: 1.75;
}

.version-grid {
  display: grid;
  grid-template-columns: 0.95fr 1.05fr;
  gap: 18px;
}

.version-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(119,183,255,0.12);
  border: 1px solid rgba(119,183,255,0.18);
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
  margin-bottom: 14px;
}

.version-current {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: flex-start;
  gap: 12px;
}

.version-current .big-version {
  font-size: clamp(30px, 5vw, 52px);
  line-height: 1;
  letter-spacing: -0.05em;
  font-weight: 800;
  margin: 0;
}

.version-current .version-note {
  margin: 0;
  color: var(--muted);
  line-height: 1.8;
}

.changelog-card {
  max-height: 640px;
  display: flex;
  flex-direction: column;
}

.changelog-scroll {
  margin-top: 12px;
  padding-right: 6px;
  overflow-y: auto;
  overscroll-behavior: contain;
  flex: 1;
  min-height: 0;
}

.changelog-scroll::-webkit-scrollbar {
  width: 8px;
}

.changelog-scroll::-webkit-scrollbar-track {
  background: rgba(255,255,255,0.04);
  border-radius: 999px;
}

.changelog-scroll::-webkit-scrollbar-thumb {
  background: rgba(119,183,255,0.35);
  border-radius: 999px;
}

.changelog-scroll::-webkit-scrollbar-thumb:hover {
  background: rgba(119,183,255,0.55);
}

.changelog-list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.changelog-item {
  padding: 16px;
  border-radius: 16px;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.06);
}

.changelog-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
  flex-wrap: wrap;
}

.changelog-head strong {
  font-size: 18px;
  line-height: 1.2;
}

.changelog-date {
  color: var(--muted);
  font-size: 13px;
}

.changelog-item ul {
  margin: 0;
  padding-left: 18px;
  color: var(--muted);
  line-height: 1.75;
}

.changelog-item li + li {
  margin-top: 6px;
}

/* Docs page */

.layout {
  padding: 18px 0 72px;
}

.docs-layout {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 20px;
  align-items: start;
}

.toc-wrap {
  position: sticky;
  top: 92px;
}

.toc-card {
  border-radius: 22px;
  padding: 18px;
}

.toc-card h2 {
  margin: 0 0 14px;
  font-size: 18px;
}

.toc-list {
  display: grid;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.toc-list a {
  display: block;
  padding: 10px 12px;
  border-radius: 12px;
  color: var(--muted);
  background: rgba(255,255,255,0.03);
  border: 1px solid rgba(255,255,255,0.04);
  transition: 0.18s ease;
}

.toc-list a:hover {
  color: var(--text);
  background: rgba(255,255,255,0.06);
}

.content {
  display: grid;
  gap: 18px;
  min-width: 0;
}

.section-title {
  margin: 0 0 10px;
  font-size: clamp(24px, 3vw, 34px);
  letter-spacing: -0.03em;
}

.section-lead {
  margin: 0;
  color: var(--muted);
  line-height: 1.8;
}

.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-top: 16px;
}

.tip {
  border-radius: 18px;
  padding: 18px;
  margin-top: 16px;
}

.tip.ok {
  border-color: rgba(158,243,191,0.18);
}

.tip.warn {
  border-color: rgba(255,211,138,0.18);
}

.tip strong {
  display: block;
  margin-bottom: 8px;
  font-size: 17px;
}

.tip p {
  margin: 0;
  color: var(--muted);
  line-height: 1.8;
}

/* Footer */

footer {
  border-top: 1px solid var(--line);
  padding: 28px 0 48px;
  color: var(--muted);
}

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

.footer-links {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.footer-links a {
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.06);
}

/* Language visibility */

[data-lang],
[data-lang-block] {
  display: none !important;
}

html[data-current-lang="ja"] [data-lang="ja"],
html[data-current-lang="en"] [data-lang="en"] {
  display: inline !important;
}

html[data-current-lang="ja"] [data-lang-block="ja"],
html[data-current-lang="en"] [data-lang-block="en"] {
  display: block !important;
}

/* Responsive */

@media (max-width: 980px) {
  .hero-grid,
  .portal-grid,
  .split,
  .docs-grid,
  .version-grid,
  .docs-layout,
  .grid-2 {
    grid-template-columns: 1fr;
  }

  .toc-wrap {
    position: static;
  }

  .changelog-card {
    max-height: 560px;
  }
}

@media (max-width: 720px) {
  .container {
    width: min(calc(100% - 20px), var(--max));
  }

  .nav {
    position: static;
  }

  .nav-inner {
    min-height: 0;
    align-items: stretch;
    flex-direction: column;
    padding-top: 12px;
    padding-bottom: 12px;
    gap: 12px;
  }

  .brand {
    gap: 10px;
    align-self: flex-start;
    max-width: 100%;
  }

  .brand-mark {
    width: 32px;
    height: 32px;
    border-radius: 10px;
    font-size: 14px;
  }

  .brand span:last-child {
    font-size: 16px;
    line-height: 1.2;
    max-width: calc(100vw - 92px);
  }

  .nav-links {
    width: 100%;
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px;
  }

  .nav-links > a,
  .nav-links > .lang-switch {
    width: 100%;
  }

  .nav-links a,
  .lang-btn {
    width: 100%;
    min-height: 42px;
    padding: 10px 12px;
    text-align: center;
    justify-content: center;
  }

  .lang-switch {
    grid-column: 1 / -1;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
  }

  .hero {
    padding: 28px 0 42px;
  }

  .hero-grid,
  .portal-grid,
  .split,
  .docs-grid,
  .version-grid,
  .docs-layout,
  .grid-2 {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .hero-main,
  .hero-card,
  .hero-side,
  .side-card,
  .card,
  .page-card,
  .notice,
  .faq-item,
  .toc-card,
  .tip {
    border-radius: 18px;
  }

  .hero-main,
  .hero-card {
    padding: 22px;
  }

  .hero-side,
  .side-card {
    padding: 18px;
  }

  .stat {
    padding: 16px;
  }

  .stat strong,
  .side-card strong {
    font-size: 19px;
  }

  .section {
    padding: 22px 0 56px;
  }

  .layout {
    padding: 18px 0 56px;
  }

  .section-header {
    margin-bottom: 16px;
  }

  .section-header h2 {
    font-size: 28px;
  }

  .page-card,
  .card,
  .faq-item,
  .notice,
  .toc-card,
  .tip {
    padding: 18px;
  }

  .page-card h3,
  .card h3 {
    font-size: 20px;
  }

  .mini-grid {
    grid-template-columns: 1fr;
  }

  .hero-actions,
  .footer-links {
    gap: 8px;
  }

  .btn {
    width: 100%;
  }

  .footer-inner {
    align-items: flex-start;
  }

  .changelog-card {
    max-height: 520px;
  }
}