:root {
  color-scheme: light;
  --bg-primary: #fafbfe;
  --bg-secondary: #ffffff;
  --bg-stage: #f8f6ff;
  --bg-overlay: rgba(255, 255, 255, 0.85);
  --text-primary: #1a1a2e;
  --text-secondary: #6b7280;
  --text-tertiary: #9ca3af;
  --accent-coral: #ff6b8a;
  --accent-coral-soft: rgba(255, 107, 138, 0.16);
  --accent-purple: #a78bfa;
  --border-subtle: #e5e7eb;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-full: 999px;
  --font-display: "Bricolage Grotesque", "Hiragino Sans", "Noto Sans JP", system-ui, sans-serif;
  --font-body: "DM Sans", -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP",
    sans-serif;
}

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

html,
body {
  margin: 0;
  padding: 0;
}

body {
  min-height: 100dvh;
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent-coral);
}

#app {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: 60px;
  background: var(--bg-overlay);
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  border-bottom: 1px solid var(--border-subtle);
}

.site-header__inner {
  max-width: 1200px;
  margin: 0 auto;
  height: 100%;
  padding: 0 20px;
  padding-left: max(20px, env(safe-area-inset-left));
  padding-right: max(20px, env(safe-area-inset-right));
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  color: var(--accent-coral);
}

.brand__icon {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  display: block;
}

.brand__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 22px;
  letter-spacing: -0.01em;
}

.lang-toggle {
  display: inline-flex;
  background: #f3f0ff;
  border-radius: 8px;
  padding: 2px;
}

.lang-toggle__btn {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--text-secondary);
  padding: 6px 14px;
  border-radius: 8px;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.05em;
  cursor: pointer;
  font-family: var(--font-body);
}

.lang-toggle__btn.is-active {
  background: var(--accent-coral);
  color: #ffffff;
  font-weight: 600;
}

.site-main {
  flex: 1;
}

.doc {
  max-width: 760px;
  margin: 0 auto;
  padding: 56px 20px 96px;
  user-select: text;
  -webkit-user-select: text;
}

.doc h1 {
  font-family: var(--font-display);
  font-size: clamp(26px, 4vw, 34px);
  font-weight: 800;
  letter-spacing: -0.01em;
  margin: 0 0 8px;
  color: var(--text-primary);
}

.doc .doc__updated {
  color: var(--text-tertiary);
  font-size: 13px;
  margin: 0 0 32px;
}

.doc h2 {
  font-size: 17px;
  font-weight: 700;
  margin: 32px 0 8px;
  color: var(--text-primary);
}

.doc p,
.doc li {
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.75;
}

.doc ul,
.doc ol {
  padding-left: 1.4em;
}

.doc a {
  color: var(--accent-coral);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.doc__back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 40px;
  padding: 12px 20px;
  background: var(--accent-coral);
  color: #ffffff !important;
  text-decoration: none !important;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 14px;
  box-shadow: 0 4px 12px rgba(255, 107, 138, 0.3);
}

.doc__back:hover {
  background: #ff5d80;
}

.doc--center {
  text-align: center;
}

.doc--center h1 {
  font-size: clamp(48px, 12vw, 72px);
  color: var(--accent-coral);
  margin: 32px 0 8px;
}

.doc--center .doc__lead {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  margin: 8px 0 0;
}

.site-footer {
  padding: 20px 16px calc(20px + env(safe-area-inset-bottom));
  border-top: 1px solid var(--border-subtle);
  background: var(--bg-secondary);
  color: var(--text-tertiary);
  font-size: 11px;
}

.site-footer__inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.site-footer__nav {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.site-footer__nav a {
  color: var(--text-tertiary);
  text-decoration: none;
}

.site-footer__nav a:hover {
  color: var(--text-primary);
}