:root {
  --paper: #F7F2E8;
  --paper-2: #EFE8DA;
  --surface: #FFFDF8;
  --ink: #1B1F3B;
  --ink-2: #555A78;
  --line: rgba(27, 31, 59, 0.12);
  --coral: #FF6A3D;
  --coral-text: #C9431A;
  --night: #14172E;
  --night-2: #2A2F5C;
  --radius: 20px;
  --serif: "PT Serif", Georgia, serif;
  --sans: "Inter", "Noto Sans JP", system-ui, -apple-system, sans-serif;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #121428;
    --paper-2: #1A1D38;
    --surface: #1C1F3C;
    --ink: #F2EEE6;
    --ink-2: #A9ADCB;
    --line: rgba(242, 238, 230, 0.12);
    --coral-text: #FF8A63;
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 17px/1.65 var(--sans);
  -webkit-font-smoothing: antialiased;
}
:lang(ja) body, body:lang(ja) { font-family: "Inter", "Noto Sans JP", system-ui, sans-serif; line-height: 1.8; }
img, svg { display: block; max-width: 100%; height: auto; }
a { color: inherit; }
h1, h2, h3 { margin: 0; line-height: 1.15; }
h1, h2 { font-family: var(--serif); font-weight: 700; letter-spacing: -0.01em; }
:lang(ja) h1, :lang(ja) h2 { font-family: "PT Serif", "Noto Sans JP", serif; letter-spacing: 0; line-height: 1.3; word-break: auto-phrase; text-wrap: balance; }
:lang(ja) h1 { font-size: clamp(32px, 4.3vw, 54px); }

.wrap { width: min(1160px, 100% - 32px); margin-inline: auto; }
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 16px; top: 16px; z-index: 10; background: var(--surface); padding: 8px 12px; border-radius: 8px; }
:focus-visible { outline: 3px solid var(--coral); outline-offset: 3px; border-radius: 6px; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 5;
  background: color-mix(in srgb, var(--paper) 85%, transparent);
  backdrop-filter: saturate(1.4) blur(12px);
  -webkit-backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; gap: 32px; height: 64px; }
.brand svg { height: 30px; width: auto; }
.nav { display: flex; gap: 28px; margin-left: auto; font-size: 15px; font-weight: 500; }
.nav a, .lang-switch { text-decoration: none; color: var(--ink-2); }
.nav a:hover, .lang-switch:hover { color: var(--ink); }
.lang-switch { font-size: 14px; font-weight: 500; border: 1px solid var(--line); padding: 4px 12px; border-radius: 999px; }

/* Hero */
.hero { display: grid; grid-template-columns: 1fr 1.15fr; gap: 56px; align-items: center; padding-block: 88px 72px; }
.eyebrow { margin: 0 0 16px; font-size: 14px; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; color: var(--coral-text); }
:lang(ja) .eyebrow { text-transform: none; letter-spacing: 0.02em; }
h1 { font-size: clamp(40px, 5.4vw, 68px); }
.lede { font-size: 19px; color: var(--ink-2); margin: 24px 0 36px; max-width: 34em; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; }
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  height: 48px; padding: 0 22px; border-radius: 999px;
  font-weight: 600; font-size: 16px; text-decoration: none;
}
.btn-primary { background: var(--ink); color: var(--paper); cursor: default; }
.btn-mark svg { width: 22px; height: 22px; }
.btn-ghost { border: 1.5px solid var(--line); }
.btn-ghost:hover { border-color: var(--ink); }
.hero-art { margin: 0; }
.hero-art img {
  width: 100%; border-radius: 24px;
  box-shadow: 0 1px 0 var(--line), 0 30px 60px -30px rgba(20, 23, 46, 0.45);
}
.hero-art figcaption { margin-top: 14px; font-size: 14px; color: var(--ink-2); text-align: center; }

/* Sections */
.section { padding-block: 72px; }
.section h2 { font-size: clamp(30px, 3.6vw, 44px); max-width: 20em; }
.section-lede { color: var(--ink-2); margin: 16px 0 0; font-size: 18px; }

.cards { list-style: none; margin: 44px 0 0; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 28px; }
.card-icon { display: block; width: 48px; height: 48px; margin-bottom: 20px; color: var(--ink); }
.card-icon svg { width: 48px; height: 48px; }
.card h3 { font-size: 19px; font-weight: 600; margin-bottom: 8px; }
.card p { margin: 0; color: var(--ink-2); font-size: 15.5px; }

.formats { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-top: 36px; }
.format-col { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 28px; }
.format-col h3 { font-size: 14px; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-2); margin-bottom: 16px; }
.chips { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 10px; }
.chips li { border: 1px solid var(--line); background: var(--paper); border-radius: 999px; padding: 6px 16px; font-weight: 500; font-size: 15px; }
.chips-lg { margin-top: 28px; }
.chips-lg li { font-size: 17px; padding: 8px 20px; }
.note { color: var(--ink-2); font-size: 14px; margin: 16px 0 0; }

/* AI */
.ai { background: linear-gradient(180deg, var(--night-2), var(--night)); color: #F2EEE6; padding-block: 96px; margin-block: 40px; }
.ai-inner { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; }
.ai h2 { font-size: clamp(30px, 3.6vw, 44px); margin-bottom: 20px; }
.ai p { color: #C9CCE8; margin: 0 0 16px; }
.ai .eyebrow { color: #FF8A63; }
.code {
  margin: 0; padding: 28px; border-radius: var(--radius);
  background: rgba(0, 0, 0, 0.35); border: 1px solid rgba(255, 255, 255, 0.1);
  font: 14px/1.7 ui-monospace, "SF Mono", Menlo, monospace; color: #F2EEE6;
  overflow-x: auto; white-space: pre;
}
.code .c { color: #8A8FB5; }

/* Closing */
.closing { text-align: center; display: flex; flex-direction: column; align-items: center; padding-bottom: 96px; }
.closing-icon { width: 120px; margin-bottom: 28px; filter: drop-shadow(0 16px 24px rgba(20, 23, 46, 0.3)); }
.closing p { color: var(--ink-2); font-size: 18px; margin: 12px 0 32px; }
.req { margin: 0; border: 1px solid var(--line); border-radius: 999px; padding: 10px 22px; display: flex; gap: 12px; font-size: 15px; }
.req dt { font-weight: 600; }
.req dd { margin: 0; color: var(--ink-2); }

/* Footer */
.site-footer { border-top: 1px solid var(--line); padding-block: 28px; font-size: 14px; color: var(--ink-2); }
.footer-inner { display: flex; align-items: center; gap: 16px; }
.footer-inner a { margin-left: auto; }
.footer-mark svg { width: 28px; height: 28px; color: var(--ink); }

@media (max-width: 900px) {
  .hero, .ai-inner { grid-template-columns: 1fr; gap: 40px; }
  .hero { padding-block: 48px; }
  .cards { grid-template-columns: repeat(2, 1fr); }
  .nav { display: none; }
  .lang-switch { margin-left: auto; }
}
@media (max-width: 600px) {
  .cards, .formats { grid-template-columns: 1fr; }
  .section { padding-block: 56px; }
  .ai { padding-block: 64px; }
  .code { font-size: 12.5px; padding: 20px; }
  .req { flex-direction: column; gap: 2px; border-radius: 16px; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }