/* OBCC Design Tokens — oceanic palette (not green-eco template) */
:root {
  --navy: #063A4A;
  --ocean: #087E9C;
  --turquoise: #17A6A0;
  --sand: #E9DFC9;
  --off: #F7F8F4;
  --leaf: #5D8A57;
  --ink: #263238;
  --white: #fff;

  --navy-rgb: 6, 58, 74;
  --ocean-rgb: 8, 126, 156;
  --ink-muted: #5a6b73;
  --line: rgba(6, 58, 74, 0.12);
  --line-strong: rgba(6, 58, 74, 0.22);

  --font-en: system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-jp: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic UI", "Yu Gothic", Meiryo, system-ui, sans-serif;

  --max: 1120px;
  --max-wide: 1280px;
  --header-h: 72px;
  --radius: 4px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --shadow-soft: 0 12px 40px rgba(6, 58, 74, 0.1);
}

/* Base — reset, typography, buttons, wrap, utilities */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-jp);
  color: var(--ink);
  background: var(--off);
  line-height: 1.8;
  font-size: 16px;
  font-weight: 400;
  overflow-x: hidden;
}

img,
picture,
svg {
  max-width: 100%;
  display: block;
  height: auto;
}

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

ul,
ol {
  list-style: none;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  cursor: pointer;
}

:focus-visible {
  outline: 2px solid var(--ocean);
  outline-offset: 3px;
}

.wrap {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
}

.wrap-wide {
  max-width: var(--max-wide);
}

/* Typography */
.eyebrow,
.kicker {
  display: inline-block;
  font-family: var(--font-en);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ocean);
  margin-bottom: 12px;
}

h1,
h2,
h3,
h4 {
  font-weight: 700;
  line-height: 1.35;
  color: var(--navy);
  letter-spacing: 0.02em;
}

h2 {
  font-size: clamp(1.5rem, 2.4vw, 2rem);
  margin-bottom: 12px;
}

h3 {
  font-size: 1.125rem;
}

.section-head {
  margin-bottom: 40px;
}

.section-head p {
  color: var(--ink-muted);
  max-width: 40em;
  margin-top: 8px;
}

.lead {
  font-size: 1.05rem;
  color: var(--ink-muted);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 48px;
  padding: 0 28px;
  font-family: var(--font-jp);
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  border-radius: 999px;
  border: 1.5px solid transparent;
  transition: background 0.25s var(--ease), color 0.25s var(--ease),
    border-color 0.25s var(--ease), transform 0.25s var(--ease),
    box-shadow 0.25s var(--ease);
}

.btn:hover {
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

.btn.is-disabled,
.btn[aria-disabled="true"] {
  opacity: 0.55;
  pointer-events: none;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--ocean);
  color: var(--white);
  box-shadow: 0 8px 24px rgba(var(--ocean-rgb), 0.28);
}

.btn-primary:hover {
  background: var(--turquoise);
  box-shadow: 0 10px 28px rgba(23, 166, 160, 0.3);
}

.btn-outline {
  background: transparent;
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.65);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: var(--white);
}

.btn-ghost {
  background: transparent;
  color: var(--navy);
  border-color: var(--line-strong);
}

.btn-ghost:hover {
  border-color: var(--ocean);
  color: var(--ocean);
}

.btn-on-dark {
  background: var(--white);
  color: var(--navy);
}

.btn-on-dark:hover {
  background: var(--sand);
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* Image notes */
.img-note {
  display: block;
  margin-top: 8px;
  font-size: 0.75rem;
  color: var(--ink-muted);
  letter-spacing: 0.02em;
}

.img-note::before {
  content: "※ ";
}

/* Utilities */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

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

.mt-0 {
  margin-top: 0;
}

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

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Layout — sticky header, mobile nav, footer */
.site-header {
  position: sticky;
  top: 0;
  z-index: 200;
  background: rgba(247, 248, 244, 0.92);
  border-bottom: 1px solid transparent;
  transition: background 0.35s var(--ease), border-color 0.35s var(--ease),
    box-shadow 0.35s var(--ease);
  overflow: visible;
}

.site-header.is-solid {
  background: rgba(247, 248, 244, 0.96);
  border-bottom-color: var(--line);
  box-shadow: 0 4px 24px rgba(var(--navy-rgb), 0.06);
}

.site-header.is-over-hero:not(.is-solid) {
  background: rgba(6, 58, 74, 0.72);
}

.site-header.is-over-hero:not(.is-solid) .brand-mark {
  background: rgba(255, 255, 255, 0.18);
  color: var(--white);
  border: 1px solid rgba(255, 255, 255, 0.35);
}

.site-header.is-over-hero:not(.is-solid) .brand-text .ja,
.site-header.is-over-hero:not(.is-solid) .brand-text .en,
.site-header.is-over-hero:not(.is-solid) .site-nav a {
  color: var(--white);
}

.site-header.is-over-hero:not(.is-solid) .nav-toggle span {
  background: var(--white);
}

.site-header.is-over-hero:not(.is-solid) .btn-nav-cta {
  background: rgba(255, 255, 255, 0.14);
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.55);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  max-width: var(--max-wide);
  margin: 0 auto;
  padding: 12px 24px;
  min-height: var(--header-h);
  position: relative;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  flex-shrink: 1;
}

.brand-mark {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  background: linear-gradient(145deg, var(--ocean), var(--navy));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-family: var(--font-en);
  font-weight: 700;
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  flex-shrink: 0;
}

.brand-text {
  line-height: 1.35;
  min-width: 0;
  flex-shrink: 0;
}

.brand-text .ja {
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--navy);
}

.brand-text .ja-line {
  display: block;
  white-space: nowrap;
}

.brand-text .en {
  font-family: var(--font-en);
  font-size: 0.625rem;
  color: var(--ink-muted);
  letter-spacing: 0.06em;
  margin-top: 2px;
  white-space: nowrap;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 1 1 auto;
  justify-content: flex-end;
  min-width: 0;
}

.site-nav ul {
  display: flex;
  align-items: center;
  gap: 2px 8px;
  flex-wrap: nowrap;
  justify-content: flex-end;
}

.site-nav a {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--ink-muted);
  padding: 6px 2px;
  white-space: nowrap;
  transition: color 0.2s;
}

.site-nav a:hover {
  color: var(--ocean);
}

/* デスクトップは英語ラベルのみ */
.site-nav .nav-index,
.site-nav .nav-jp {
  display: none;
}

.site-nav .nav-copy {
  display: contents;
}

.site-nav .nav-en {
  display: inline;
}

.btn-nav-cta {
  min-height: 40px;
  padding: 0 18px;
  font-size: 0.8125rem;
  background: var(--navy);
  color: var(--white);
  border: 1.5px solid var(--navy);
  margin-left: 8px;
  flex-shrink: 0;
}

.btn-nav-cta:hover {
  background: var(--ocean);
  border-color: var(--ocean);
}

/* デスクトップはヘッダー右のCTAのみ。ナビ内CTAはモバイルオーバーレイ用 */
.site-nav > .btn-nav-cta {
  display: none;
}

.lang-switch {
  flex-shrink: 0;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--navy);
  border: 1.5px solid var(--line-strong);
  min-height: 36px;
  padding: 0 12px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius);
  z-index: 220;
}

.lang-switch:hover {
  color: var(--ocean);
  border-color: var(--ocean);
}

.site-header.is-over-hero:not(.is-solid) .lang-switch {
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.45);
}

.site-header.is-over-hero:not(.is-solid) .lang-switch:hover {
  border-color: var(--white);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  flex-shrink: 0;
  z-index: 220;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  margin: 0 auto;
  background: var(--navy);
  border-radius: 2px;
  transition: transform 0.25s var(--ease), opacity 0.2s;
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.nav-overlay {
  display: none;
}

/* ノートPC幅でも横並びメニューを優先（三本線は 900px 以下のみ） */
@media (min-width: 901px) and (max-width: 1180px) {
  .header-inner {
    padding: 10px 16px;
    gap: 10px;
  }

  .brand-text .ja {
    font-size: 0.75rem;
  }

  .brand-text .en {
    font-size: 0.5625rem;
    letter-spacing: 0.04em;
  }

  .btn-nav-cta {
    padding: 0 12px;
    min-height: 36px;
    font-size: 0.75rem;
    margin-left: 4px;
  }
}

@media (min-width: 1200px) {
  .site-nav a {
    font-size: 0.8125rem;
  }

  .site-nav ul {
    gap: 4px 10px;
  }
}

@media (max-width: 900px) {
  .nav-toggle {
    display: flex;
    border-radius: 50%;
  }

  .btn-nav-cta--desktop {
    display: none;
  }

  .site-nav {
    position: fixed;
    inset: 0;
    width: 100%;
    height: 100%;
    min-height: 100svh;
    min-height: 100dvh;
    z-index: 10050;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: stretch;
    padding: calc(var(--header-h) + 20px) clamp(24px, 6vw, 40px) 32px;
    background:
      radial-gradient(ellipse 90% 55% at 110% -10%, rgba(23, 166, 160, 0.38), transparent 58%),
      radial-gradient(ellipse 70% 45% at -15% 110%, rgba(8, 126, 156, 0.42), transparent 55%),
      linear-gradient(160deg, #042833 0%, #063A4A 42%, #0a5163 100%);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.35s var(--ease), visibility 0.35s;
  }

  .site-nav::before {
    content: "";
    position: absolute;
    inset: 0;
    background:
      linear-gradient(90deg, transparent 0%, rgba(255, 255, 255, 0.04) 50%, transparent 100%);
    opacity: 0.5;
    pointer-events: none;
  }

  .site-nav.is-open {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }

  body.nav-open {
    overflow: hidden;
  }

  body.nav-open .site-header {
    z-index: 10060;
    background: transparent;
    border-bottom-color: transparent;
    box-shadow: none;
  }

  body.nav-open .brand,
  body.nav-open .nav-toggle,
  body.nav-open .lang-switch {
    position: relative;
    z-index: 10070;
  }

  body.nav-open .lang-switch {
    color: var(--white);
    border-color: rgba(255, 255, 255, 0.45);
  }

  body.nav-open .brand-mark {
    background: rgba(255, 255, 255, 0.14);
    color: var(--white);
    border: 1px solid rgba(255, 255, 255, 0.28);
  }

  body.nav-open .site-header .brand-text .ja,
  body.nav-open .site-header .brand-text .en {
    color: var(--white);
  }

  body.nav-open .nav-toggle span {
    background: var(--white);
  }

  .site-nav ul {
    position: relative;
    z-index: 1;
    flex: 1 1 auto;
    flex-direction: column;
    align-items: stretch;
    justify-content: center;
    gap: 0;
    width: 100%;
    max-width: 22rem;
    margin: 0 auto;
    min-height: 0;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }

  .site-nav .nav-index,
  .site-nav .nav-jp {
    display: block;
  }

  .site-nav .nav-copy {
    display: flex;
    flex-direction: column;
    gap: 2px;
    min-width: 0;
  }

  .site-nav a {
    display: grid;
    grid-template-columns: 2rem 1fr;
    align-items: center;
    gap: 12px;
    color: var(--white);
    font-size: clamp(1.2rem, 4vw, 1.45rem);
    font-family: var(--font-en);
    font-weight: 600;
    letter-spacing: 0.02em;
    line-height: 1.15;
    padding: 0.55rem 0.25rem;
    border-bottom: none;
    border-radius: 2px;
    transition: transform 0.25s var(--ease), color 0.2s;
  }

  .site-nav a:hover,
  .site-nav a:focus-visible {
    color: #9ee8e3;
    transform: translateX(4px);
  }

  .site-nav .nav-index {
    font-size: 0.6875rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    color: rgba(158, 232, 227, 0.7);
    align-self: start;
    padding-top: 0.45em;
  }

  .site-nav .nav-en {
    display: block;
  }

  .site-nav .nav-jp {
    font-family: var(--font-jp);
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.06em;
    color: rgba(255, 255, 255, 0.58);
    line-height: 1.4;
  }

  .site-nav.is-open li {
    animation: navItemIn 0.5s var(--ease) both;
  }

  .site-nav.is-open li:nth-child(1) { animation-delay: 0.04s; }
  .site-nav.is-open li:nth-child(2) { animation-delay: 0.08s; }
  .site-nav.is-open li:nth-child(3) { animation-delay: 0.12s; }
  .site-nav.is-open li:nth-child(4) { animation-delay: 0.16s; }
  .site-nav.is-open li:nth-child(5) { animation-delay: 0.2s; }
  .site-nav.is-open li:nth-child(6) { animation-delay: 0.24s; }
  .site-nav.is-open li:nth-child(7) { animation-delay: 0.28s; }
  .site-nav.is-open li:nth-child(8) { animation-delay: 0.32s; }

  .site-nav.is-open .btn-nav-cta {
    animation: navItemIn 0.5s var(--ease) 0.38s both;
  }

  @keyframes navItemIn {
    from {
      opacity: 0;
      transform: translateY(14px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  .site-nav .btn-nav-cta {
    position: relative;
    z-index: 1;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    align-self: stretch;
    flex-shrink: 0;
    width: 100%;
    max-width: 22rem;
    margin: 16px auto 0;
    min-height: 48px;
    padding: 0 24px;
    padding-bottom: env(safe-area-inset-bottom, 0);
    font-size: 0.9375rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    background: rgba(23, 166, 160, 0.22);
    border: 1.5px solid rgba(158, 232, 227, 0.65);
    color: var(--white);
    border-radius: var(--radius);
    transition: background 0.25s var(--ease), border-color 0.25s, color 0.25s;
  }

  .site-nav .btn-nav-cta:hover,
  .site-nav .btn-nav-cta:focus-visible {
    background: var(--turquoise);
    border-color: var(--turquoise);
    color: var(--white);
  }

  .brand-text .ja {
    font-size: 0.75rem;
  }

  .brand-text .en {
    font-size: 0.5rem;
    letter-spacing: 0.03em;
  }
}

@media (max-width: 640px) {
  .brand-text .en {
    display: none;
  }

  .brand-text .ja {
    font-size: 0.6875rem;
  }
}

/* Footer */
.site-footer {
  background: var(--navy);
  color: rgba(255, 255, 255, 0.82);
  padding: 64px 0 28px;
}

.site-footer a:hover {
  color: var(--white);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}

.site-footer .brand-mark {
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.site-footer .brand-text .ja {
  color: var(--white);
}

.site-footer .brand-text .en {
  color: rgba(255, 255, 255, 0.55);
}

.footer-copy {
  margin-top: 16px;
  font-size: 0.875rem;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.65);
  max-width: 28em;
}

.footer-heading {
  font-size: 0.75rem;
  font-family: var(--font-en);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.45);
  margin-bottom: 12px;
  margin-top: 0;
}

.footer-heading + p,
.footer-heading + ul {
  margin-bottom: 24px;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-links a {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.75);
}

.footer-credits {
  margin: 0 0 28px;
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  font-size: 0.75rem;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.5);
}

.footer-credits .footer-heading {
  margin-bottom: 10px;
}

.footer-credits ul {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-credits a {
  color: rgba(255, 255, 255, 0.65);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.footer-credits a:hover {
  color: var(--white);
}

.footer-credits-more {
  display: inline-block;
  margin-top: 12px;
  font-size: 0.8125rem;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.75);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.5);
}

.footer-copyright {
  font-family: var(--font-en);
  line-height: 1.55;
  letter-spacing: 0.01em;
}

.footer-mail {
  color: var(--white);
  font-family: var(--font-en);
  letter-spacing: 0.02em;
}

@media (max-width: 800px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}