/*
  Watagumo public site — shared stylesheet.
  Self-contained, no external CDN, no build step.
  Color tokens follow .company/creative/brand-guidelines.md (light/dark).
*/

:root {
  --bg-canvas: #F5F8FB;
  --bg-surface: #FFFFFF;
  --bg-card: #FFFFFF;
  --bg-muted: #EDF2F7;
  --border-subtle: #E4EAF1;
  --border-default: #D5DEE7;
  --border-strong: #7E8C99;
  --primary: #3771A8;
  --primary-pressed: #2E6293;
  --primary-subtle: #EDF3FA;
  --text-on-primary: #FFFFFF;
  --accent-text: #9C514A;
  --accent-subtle: #FBEDEB;
  --text-primary: #22303D;
  --text-secondary: #566675;
  --text-tertiary: #61707C;
  --warning: #8A6420;
  --warning-subtle: #FAF0DE;
  --error: #B0453F;
  --error-subtle: #FBE9E7;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-canvas: #0F151D;
    --bg-surface: #161E28;
    --bg-card: #1C2531;
    --bg-muted: #232D3A;
    --border-subtle: #2A3542;
    --border-default: #37444F;
    --border-strong: #66747F;
    --primary: #8FBEE8;
    --primary-pressed: #A9CFEE;
    --primary-subtle: #1D2B3A;
    --text-on-primary: #0F151D;
    --accent-text: #F0B3AB;
    --accent-subtle: #2E1D1C;
    --text-primary: #E9EFF5;
    --text-secondary: #A5B3C1;
    --text-tertiary: #8391A0;
    --warning: #E0AC63;
    --warning-subtle: #2E2617;
    --error: #E88F8A;
    --error-subtle: #2E1D1C;
  }
}

* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  padding: 0;
  background: var(--bg-canvas);
  color: var(--text-primary);
  font-family: -apple-system, "Hiragino Sans", "Hiragino Kaku Gothic ProN",
    "Noto Sans CJK JP", "Malgun Gothic", "Apple SD Gothic Neo",
    "PingFang TC", "PingFang SC", "Segoe UI", Roboto, sans-serif;
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--primary);
  text-decoration: underline;
  text-underline-offset: 2px;
}

a:hover,
a:focus {
  color: var(--primary-pressed);
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: auto;
  background: var(--primary);
  color: var(--text-on-primary);
  padding: 10px 16px;
  border-radius: 8px;
  z-index: 100;
  text-decoration: none;
}

.skip-link:focus {
  left: 12px;
  top: 12px;
}

.site-header {
  border-bottom: 1px solid var(--border-subtle);
  background: var(--bg-surface);
}

.site-header__inner {
  max-width: 760px;
  margin: 0 auto;
  padding: 20px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.brand {
  font-size: 19px;
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
  letter-spacing: -0.2px;
}

.brand:hover,
.brand:focus {
  color: var(--text-primary);
}

.lang-switch {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 13px;
}

.lang-switch li {
  display: inline;
}

.lang-switch a {
  display: inline-block;
  padding: 6px 10px;
  border-radius: 8px;
  text-decoration: none;
  color: var(--text-secondary);
  border: 1px solid transparent;
}

.lang-switch a[aria-current="true"] {
  color: var(--primary);
  border-color: var(--border-default);
  background: var(--primary-subtle);
  font-weight: 600;
}

.lang-switch a:hover {
  background: var(--bg-muted);
}

main {
  max-width: 760px;
  margin: 0 auto;
  padding: 32px 20px 80px;
}

.page-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 32px;
  padding: 0;
  list-style: none;
}

.page-nav a {
  display: inline-block;
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid var(--border-default);
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
}

.page-nav a[aria-current="page"] {
  color: var(--primary);
  border-color: var(--primary);
  background: var(--primary-subtle);
  font-weight: 600;
}

.page-nav a:hover {
  background: var(--bg-muted);
}

h1 {
  font-size: 28px;
  line-height: 1.4;
  font-weight: 600;
  margin: 0 0 8px;
  letter-spacing: -0.3px;
}

h2 {
  font-size: 21px;
  line-height: 1.45;
  font-weight: 600;
  margin: 40px 0 12px;
  padding-top: 8px;
  border-top: 1px solid var(--border-subtle);
}

h2:first-of-type {
  border-top: none;
  margin-top: 24px;
}

h3 {
  font-size: 17px;
  line-height: 1.5;
  font-weight: 600;
  margin: 24px 0 8px;
}

p {
  margin: 0 0 14px;
  color: var(--text-primary);
}

.lead {
  color: var(--text-secondary);
  font-size: 16px;
  margin-bottom: 28px;
}

ul, ol {
  margin: 0 0 16px;
  padding-left: 22px;
}

li {
  margin-bottom: 6px;
}

.updated {
  color: var(--text-tertiary);
  font-size: 13px;
  margin-bottom: 20px;
}

table {
  border-collapse: collapse;
  width: 100%;
  margin: 0 0 20px;
  font-size: 14px;
}

caption {
  text-align: left;
  font-size: 13px;
  color: var(--text-tertiary);
  margin-bottom: 6px;
}

th, td {
  border: 1px solid var(--border-default);
  padding: 8px 10px;
  text-align: left;
  vertical-align: top;
}

th {
  background: var(--bg-muted);
  font-weight: 600;
}

.table-scroll {
  overflow-x: auto;
  margin-bottom: 20px;
  border-radius: 12px;
}

.table-scroll table {
  margin-bottom: 0;
}

.notice {
  background: var(--warning-subtle);
  border: 1px solid var(--border-default);
  border-radius: 14px;
  padding: 16px 18px;
  margin: 0 0 28px;
}

.notice p:last-child {
  margin-bottom: 0;
}

.notice strong {
  color: var(--warning);
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 18px;
  padding: 20px 22px;
  margin: 0 0 20px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 18px;
  padding: 18px 20px;
  margin: 0 0 14px;
}

.faq-item h3 {
  margin-top: 0;
  margin-bottom: 8px;
}

.faq-item p:last-child {
  margin-bottom: 0;
}

.contact-block {
  background: var(--primary-subtle);
  border: 1px solid var(--border-default);
  border-radius: 18px;
  padding: 18px 20px;
  margin: 0 0 24px;
}

.contact-block a {
  font-weight: 600;
}

.ai-badge {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  color: var(--accent-text);
  background: var(--accent-subtle);
  border-radius: 999px;
  padding: 3px 10px;
  margin-bottom: 12px;
}

.placeholder {
  color: var(--text-tertiary);
  font-style: italic;
}

.toc {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 14px;
  padding: 14px 18px;
  margin: 0 0 28px;
  font-size: 14px;
}

.toc summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--text-primary);
}

.toc ul {
  margin: 10px 0 0;
}

site-footer,
.site-footer {
  border-top: 1px solid var(--border-subtle);
  margin-top: 40px;
}

.site-footer__inner {
  max-width: 760px;
  margin: 0 auto;
  padding: 24px 20px 40px;
  color: var(--text-tertiary);
  font-size: 13px;
}

.site-footer nav {
  margin-bottom: 12px;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
}

.site-footer a {
  color: var(--text-secondary);
}

hr.divider {
  border: none;
  border-top: 1px solid var(--border-subtle);
  margin: 32px 0;
}

/* language picker (root index) */
.lang-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 12px;
  margin: 24px 0 8px;
}

.lang-grid a {
  display: block;
  text-decoration: none;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 16px;
  padding: 20px 16px;
  text-align: center;
  color: var(--text-primary);
}

.lang-grid a:hover {
  border-color: var(--primary);
  background: var(--primary-subtle);
}

.lang-grid .native {
  display: block;
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 4px;
}

.lang-grid .sub {
  display: block;
  font-size: 13px;
  color: var(--text-tertiary);
}

@media (max-width: 480px) {
  h1 { font-size: 24px; }
  h2 { font-size: 19px; }
  main { padding: 24px 16px 64px; }
  .site-header__inner { padding: 16px; }
}