:root {
  color-scheme: light;
  --bg: #f4f1ec;
  --bg-soft: #ebe7dd;
  --surface: #ffffff;
  --surface-soft: rgba(255, 255, 255, 0.78);
  --ink: #172028;
  --ink-strong: #0d1318;
  --muted: #66717a;
  --line: #d9d2c7;
  --line-strong: #bdb4a7;
  --accent: #2f7f78;
  --accent-strong: #205f59;
  --warm: #b8643d;
  --gold: #b58a2a;
  --nav: #17232d;
  --workshop-glow: rgba(236, 174, 80, 0.24);
  --page-gradient-start: #fbfaf7;
  --page-top-light: rgba(255, 239, 178, 0.18);
  --page-grid: rgba(23, 32, 40, 0.035);
  --header-bg: rgba(251, 250, 247, 0.92);
  --header-border: rgba(217, 210, 199, 0.9);
  --nav-active-bg: rgba(47, 127, 120, 0.10);
  --switch-bg: rgba(255, 255, 255, 0.68);
  --switch-active: var(--ink-strong);
  --switch-active-text: #ffffff;
  --hero-bg:
    radial-gradient(circle at 14% 12%, rgba(255, 239, 178, 0.42), transparent 28%),
    radial-gradient(circle at 82% 18%, rgba(91, 170, 183, 0.18), transparent 32%),
    linear-gradient(160deg, #fffdf7 0%, #f5f1e8 58%, #e8f0ed 100%);
  --lead: #4d5962;
  --button-text: #ffffff;
  --button-secondary-bg: rgba(255, 255, 255, 0.48);
  --button-secondary-hover: #ffffff;
  --frame-bg: rgba(255, 255, 255, 0.72);
  --frame-border: rgba(23, 32, 40, 0.18);
  --card-bg: rgba(255, 255, 255, 0.78);
  --card-highlight: rgba(236, 174, 80, 0.14);
  --card-shadow: 0 12px 30px rgba(23, 32, 40, 0.06);
  --notice-bg: rgba(47, 127, 120, 0.08);
  --notice-border: rgba(47, 127, 120, 0.28);
  --notice-text: #254642;
  --shadow: 0 18px 44px rgba(23, 32, 40, 0.10);
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #071219;
  --bg-soft: #101f28;
  --surface: #101b23;
  --surface-soft: rgba(16, 27, 35, 0.82);
  --ink: #d9e3e7;
  --ink-strong: #f5f0df;
  --muted: #9fb1b8;
  --line: #263841;
  --line-strong: #3a5059;
  --accent: #69b8b1;
  --accent-strong: #99d8cf;
  --warm: #f0a96b;
  --gold: #f2c96b;
  --nav: #04090d;
  --workshop-glow: rgba(242, 201, 107, 0.18);
  --page-gradient-start: #0d1a22;
  --page-top-light: rgba(184, 220, 234, 0.16);
  --page-grid: rgba(245, 240, 223, 0.035);
  --header-bg: rgba(7, 18, 25, 0.9);
  --header-border: rgba(38, 56, 65, 0.9);
  --nav-active-bg: rgba(105, 184, 177, 0.14);
  --switch-bg: rgba(16, 27, 35, 0.72);
  --switch-active: #f5f0df;
  --switch-active-text: #071219;
  --hero-bg:
    radial-gradient(circle at 8% 0%, rgba(214, 235, 244, 0.24), transparent 34%),
    radial-gradient(circle at 18% 14%, rgba(139, 184, 205, 0.16), transparent 36%),
    radial-gradient(circle at 16% 18%, rgba(242, 201, 107, 0.06), transparent 30%),
    radial-gradient(circle at 82% 16%, rgba(105, 184, 177, 0.12), transparent 32%),
    linear-gradient(160deg, #071219 0%, #0b1820 58%, #10252c 100%);
  --lead: #b6c5cb;
  --button-text: #071219;
  --button-secondary-bg: rgba(245, 240, 223, 0.08);
  --button-secondary-hover: rgba(245, 240, 223, 0.12);
  --frame-bg: rgba(16, 27, 35, 0.74);
  --frame-border: rgba(245, 240, 223, 0.16);
  --card-bg: rgba(16, 27, 35, 0.78);
  --card-highlight: rgba(242, 201, 107, 0.10);
  --card-shadow: 0 18px 40px rgba(0, 0, 0, 0.20);
  --notice-bg: rgba(105, 184, 177, 0.12);
  --notice-border: rgba(105, 184, 177, 0.30);
  --notice-text: #bde7e0;
  --shadow: 0 22px 52px rgba(0, 0, 0, 0.26);
}

* {
  box-sizing: border-box;
}

html {
  font-family: Inter, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, system-ui, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.75;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  background:
    radial-gradient(circle at 10% 0%, var(--page-top-light), transparent 34%) 0 0 / 100% 520px no-repeat,
    linear-gradient(90deg, var(--page-grid) 1px, transparent 1px) 0 0 / 42px 42px,
    linear-gradient(180deg, var(--page-gradient-start) 0, var(--bg) 460px, var(--bg) 100%);
}

main {
  transition: opacity 180ms ease, transform 180ms ease;
}

.is-navigating main {
  opacity: 0;
  transform: translateY(8px);
}

a {
  color: var(--accent-strong);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.18em;
}

a:hover {
  color: var(--warm);
}

.site-header {
  position: sticky;
  z-index: 10;
  top: 0;
  background: var(--header-bg);
  border-bottom: 1px solid var(--header-border);
  backdrop-filter: blur(14px);
}

.header-inner,
.footer-inner,
.section {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.header-inner {
  min-height: 74px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink-strong);
  font-weight: 800;
  text-decoration: none;
  letter-spacing: 0;
}

.brand img {
  width: 38px;
  height: 38px;
  border-radius: 8px;
  box-shadow: 0 8px 20px rgba(23, 32, 40, 0.14), 0 0 0 1px var(--frame-border);
}

.brand span {
  font-size: 1.06rem;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 4px;
  font-size: 0.92rem;
}

.nav a {
  border-radius: 8px;
  padding: 8px 10px;
  color: var(--muted);
  text-decoration: none;
}

.nav a[aria-current="page"],
.nav a:hover {
  background: var(--nav-active-bg);
  color: var(--ink-strong);
}

.language-switch {
  display: inline-flex;
  flex: 0 0 auto;
  gap: 2px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 3px;
  background: var(--switch-bg);
}

.language-switch a {
  min-width: 36px;
  border: 0;
  border-radius: 6px;
  padding: 5px 8px;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 0.82rem;
  font-weight: 850;
  text-align: center;
  text-decoration: none;
}

.language-switch a[aria-current="true"],
.language-switch a:hover {
  background: var(--switch-active);
  color: var(--switch-active-text);
}

.hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background: var(--hero-bg);
}

.hero .section {
  position: relative;
  z-index: 1;
  padding: 88px 0 78px;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.7fr);
  align-items: center;
  gap: clamp(34px, 6vw, 72px);
}

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

.eyebrow {
  margin: 0 0 16px;
  color: var(--accent-strong);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  margin: 0;
  color: var(--ink-strong);
  line-height: 1.22;
  letter-spacing: 0;
}

h1 {
  max-width: 840px;
  font-size: clamp(3.2rem, 9vw, 7rem);
  font-weight: 900;
}

.hero .section:not(.hero-grid) h1 {
  font-size: clamp(2.2rem, 6vw, 4.4rem);
}

h2 {
  font-size: clamp(1.6rem, 3vw, 2.45rem);
  font-weight: 850;
}

h3 {
  font-size: 1.12rem;
  font-weight: 800;
}

p {
  margin: 0;
}

ul,
ol {
  padding-left: 1.35em;
}

li + li {
  margin-top: 8px;
}

.lead {
  max-width: 740px;
  margin-top: 20px;
  color: var(--lead);
  font-size: clamp(1.03rem, 2.1vw, 1.24rem);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--ink-strong);
  border-radius: 8px;
  padding: 10px 18px;
  background: var(--ink-strong);
  color: var(--button-text);
  font-weight: 800;
  text-decoration: none;
  box-shadow: 0 14px 26px rgba(23, 32, 40, 0.16);
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.button:hover {
  transform: translateY(-1px);
  background: var(--accent-strong);
  border-color: var(--accent-strong);
  color: var(--button-text);
  box-shadow: 0 18px 34px rgba(23, 32, 40, 0.18);
}

.button.secondary {
  background: var(--button-secondary-bg);
  border-color: var(--line-strong);
  color: var(--ink-strong);
  box-shadow: none;
}

.button.secondary:hover {
  background: var(--button-secondary-hover);
  border-color: var(--accent);
  color: var(--accent-strong);
}

.studio-frame {
  border: 1px solid var(--frame-border);
  border-radius: 8px;
  padding: 26px;
  background:
    linear-gradient(160deg, var(--workshop-glow), transparent 32%),
    linear-gradient(180deg, var(--frame-bg), var(--frame-bg));
  box-shadow: var(--shadow);
  backdrop-filter: blur(12px);
}

.studio-frame-header {
  display: flex;
  align-items: center;
  gap: 16px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--line);
}

.studio-frame-header img {
  border-radius: 8px;
  box-shadow: 0 10px 24px rgba(23, 32, 40, 0.14);
}

.frame-title {
  color: var(--ink-strong);
  font-size: 1.35rem;
  font-weight: 900;
  line-height: 1.15;
}

.frame-subtitle {
  color: var(--muted);
  font-size: 0.92rem;
}

.signal-grid {
  display: grid;
  gap: 12px;
  margin-top: 22px;
}

.signal-grid div {
  display: grid;
  grid-template-columns: 42px 1fr;
  align-items: center;
  min-height: 54px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background:
    linear-gradient(90deg, var(--card-highlight), transparent 34%),
    var(--surface);
}

.signal-grid span {
  color: var(--gold);
  font-size: 0.78rem;
  font-weight: 900;
}

.signal-grid strong {
  color: var(--ink-strong);
  font-size: 0.96rem;
}

.main {
  padding: 66px 0 82px;
}

.stack {
  display: grid;
  gap: 38px;
}

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

.app-list {
  display: grid;
  gap: 18px;
}

.app-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 26px;
  background:
    linear-gradient(135deg, var(--card-highlight), transparent 34%),
    var(--card-bg);
  box-shadow: var(--card-shadow);
}

.app-item h2 + p {
  margin-top: 10px;
}

.card {
  min-height: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 24px;
  background:
    linear-gradient(135deg, var(--card-highlight), transparent 38%),
    var(--card-bg);
  box-shadow: var(--card-shadow);
}

.card-kicker {
  display: block;
  margin-bottom: 12px;
  color: var(--warm);
  font-size: 0.76rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.card h3 + p,
.card p + p {
  margin-top: 10px;
}

.panel {
  border-top: 1px solid var(--line-strong);
  padding: 30px 0;
}

.panel:first-child {
  padding-top: 0;
  border-top: 0;
}

.panel h2 + p,
.panel h3 + p,
.panel p + p,
.panel ul,
.panel ol {
  margin-top: 14px;
}

.panel + .panel {
  margin-top: 4px;
}

.feature {
  display: grid;
  grid-template-columns: minmax(220px, 0.75fr) minmax(0, 1fr);
  gap: 28px;
  align-items: start;
  border-top: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line);
  padding: 38px 0;
}

.feature-body {
  display: grid;
  gap: 14px;
  color: var(--ink);
}

.muted {
  color: var(--muted);
}

.definition-list {
  display: grid;
  grid-template-columns: 180px minmax(0, 1fr);
  gap: 12px 20px;
  margin: 22px 0 0;
  border-top: 1px solid var(--line);
}

.definition-list dt,
.definition-list dd {
  margin: 0;
  padding-top: 14px;
}

.definition-list dt {
  color: var(--muted);
  font-weight: 800;
}

.notice {
  display: inline-flex;
  border: 1px solid var(--notice-border);
  border-radius: 8px;
  padding: 8px 12px;
  background: var(--notice-bg);
  color: var(--notice-text);
  font-size: 0.92rem;
}

.notice + h2 {
  margin-top: 18px;
}

.site-footer {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  background: var(--nav);
  color: #e9edf0;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 30px 0;
  font-size: 0.92rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-links a {
  color: #e9edf0;
}

@media (max-width: 860px) {
  .header-inner {
    align-items: center;
    justify-content: flex-start;
    padding: 14px 0;
  }

  .nav {
    justify-content: flex-start;
  }

  .language-switch {
    margin-top: 2px;
  }

  .hero .section {
    padding: 58px 0 54px;
  }

  .hero-grid,
  .feature {
    grid-template-columns: 1fr;
  }

  .studio-frame {
    max-width: 520px;
  }

  .main {
    padding: 44px 0 62px;
  }

  .grid,
  .app-item,
  .definition-list {
    grid-template-columns: 1fr;
  }

  .definition-list {
    gap: 0;
  }

  .definition-list dt {
    padding-bottom: 0;
  }

  .definition-list dd {
    padding-top: 2px;
  }
}

@media (max-width: 680px) {
  .header-inner {
    align-items: center;
    flex-direction: row;
    gap: 12px;
    padding: 14px 0;
  }

  .brand {
    order: 1;
  }

  .language-switch {
    order: 2;
    margin-top: 0;
    margin-left: auto;
  }

  .nav {
    order: 3;
    width: 100%;
    justify-content: flex-start;
  }
}

@media (max-width: 560px) {
  .header-inner,
  .footer-inner,
  .section {
    width: min(100% - 28px, 1120px);
  }

  .nav a {
    padding: 7px 8px;
  }

  h1 {
    font-size: clamp(2.8rem, 17vw, 4.2rem);
  }

  .card {
    padding: 22px;
  }

  .studio-frame {
    padding: 20px;
  }
}

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

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}