:root {
  --ink: #1f2933;
  --muted: #5d6876;
  --paper: #ffffff;
  --soft: #f2f6f4;
  --line: #d9e2dc;
  --purple: #653a78;
  --purple-deep: #3d2849;
  --green: #2f6f5f;
  --green-dark: #17483e;
  --rose: #c65672;
  --amber: #e4a547;
  --shadow: 0 18px 50px rgba(28, 42, 56, 0.14);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", "YuGothic", "Noto Sans JP", sans-serif;
  line-height: 1.75;
}

img {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
}

.skip-link {
  position: absolute;
  left: 16px;
  top: -48px;
  z-index: 20;
  padding: 8px 12px;
  background: var(--paper);
  border: 2px solid var(--purple);
}

.skip-link:focus {
  top: 16px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}

.utility {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 6px clamp(18px, 5vw, 68px);
  color: var(--paper);
  background: var(--green-dark);
  font-size: 0.88rem;
}

.utility p {
  margin: 0;
}

.utility a {
  font-weight: 700;
  text-decoration: none;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 14px clamp(18px, 5vw, 68px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  background: var(--paper);
  border: 1px solid rgba(122, 102, 157, 0.18);
  border-radius: 8px;
}

.brand-icon {
  width: 34px;
  height: 34px;
  overflow: visible;
}

.brand-iris-petal {
  fill: #7b579f;
}

.brand-iris-petal-light {
  fill: #9a7abc;
}

.brand-iris-petal-deep {
  fill: #653a78;
}

.brand-iris-center {
  fill: var(--amber);
}

.brand-iris-leaf {
  fill: var(--green);
}

.brand-iris-stem,
.brand-iris-vein {
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.brand-iris-stem {
  stroke: var(--green);
  stroke-width: 2.5;
}

.brand-iris-vein {
  stroke: rgba(255, 255, 255, 0.62);
  stroke-width: 1.4;
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  line-height: 1.2;
}

.brand small {
  color: var(--muted);
  font-size: 0.78rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 26px);
  font-size: 0.95rem;
}

.nav-links a {
  color: var(--muted);
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a:focus-visible {
  color: var(--purple);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  position: relative;
  min-height: 42px;
  padding: 8px 12px 8px 38px;
  color: var(--green-dark);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  font: inherit;
  font-weight: 800;
}

.nav-toggle span {
  display: block;
  position: absolute;
  left: 12px;
  width: 18px;
  height: 2px;
  background: currentColor;
}

.nav-toggle span:nth-child(1) {
  top: 13px;
}

.nav-toggle span:nth-child(2) {
  top: 20px;
}

.nav-toggle span:nth-child(3) {
  top: 27px;
}

.hero {
  position: relative;
  min-height: 76vh;
  display: flex;
  align-items: center;
  padding: clamp(70px, 12vh, 120px) clamp(20px, 6vw, 86px);
  color: var(--paper);
  background-image:
    linear-gradient(90deg, rgba(21, 36, 42, 0.84), rgba(21, 36, 42, 0.54) 46%, rgba(21, 36, 42, 0.16)),
    url("assets/hero-lake.jpg");
  background-position: center;
  background-size: cover;
}

.hero-content {
  width: min(760px, 100%);
}

.eyebrow,
.section-label {
  margin: 0 0 10px;
  color: var(--amber);
  font-size: 0.84rem;
  font-weight: 800;
}

.hero h1 {
  margin: 0;
  font-size: clamp(3rem, 7vw, 6rem);
  line-height: 1.02;
  letter-spacing: 0;
}

.hero-copy {
  width: min(680px, 100%);
  margin: 24px 0 0;
  font-size: clamp(1.05rem, 2vw, 1.3rem);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 48px;
  padding: 11px 18px;
  border: 2px solid transparent;
  border-radius: 8px;
  font-weight: 800;
  text-decoration: none;
}

.button.primary {
  color: var(--paper);
  background: var(--purple);
}

.button.secondary {
  color: var(--paper);
  border-color: rgba(255, 255, 255, 0.72);
}

.button.compact {
  min-height: 44px;
  padding: 8px 14px;
  font-size: 0.95rem;
}

.hero-facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  width: min(610px, 100%);
  margin: 42px 0 0;
}

.hero-facts div {
  padding: 14px 16px;
  border-left: 4px solid var(--amber);
  background: rgba(255, 255, 255, 0.13);
  backdrop-filter: blur(8px);
}

.hero-facts dt {
  color: rgba(255, 255, 255, 0.76);
  font-size: 0.82rem;
}

.hero-facts dd {
  margin: 0;
  font-size: 1.2rem;
  font-weight: 800;
}

.notice-band {
  display: grid;
  grid-template-columns: minmax(160px, 0.25fr) minmax(260px, 1fr) auto;
  align-items: center;
  gap: 24px;
  margin: -34px clamp(18px, 5vw, 68px) 0;
  padding: 22px 26px;
  position: relative;
  z-index: 2;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.notice-band h2,
.section h2,
.contact-section h2 {
  margin: 0;
  font-size: clamp(1.7rem, 3.2vw, 2.8rem);
  line-height: 1.25;
  letter-spacing: 0;
}

.notice-band p {
  margin: 0;
}

.text-link {
  color: var(--green-dark);
  font-weight: 800;
  text-decoration: underline;
  text-underline-offset: 4px;
}

.section {
  padding: clamp(70px, 10vw, 112px) clamp(18px, 5vw, 68px);
}

.section.muted {
  background: var(--soft);
}

.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 28px;
}

.section-heading.vertical {
  display: block;
  margin: 0;
}

.section-heading p {
  max-width: 560px;
  margin: 0;
  color: var(--muted);
}

.news-list {
  border-top: 1px solid var(--line);
}

.news-item {
  display: grid;
  grid-template-columns: 130px 110px 1fr;
  gap: 18px;
  align-items: center;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

.news-item time {
  color: var(--muted);
  font-weight: 700;
}

.news-item span,
.activity-card span,
.info-tile span,
.role-grid span {
  color: var(--purple);
  font-size: 0.82rem;
  font-weight: 800;
}

.news-item h3 {
  margin: 0;
  font-size: 1.05rem;
}

.split {
  display: grid;
  grid-template-columns: 0.8fr 1.1fr 0.9fr;
  gap: clamp(28px, 5vw, 64px);
  align-items: start;
}

.about-copy p {
  margin-top: 0;
  font-size: 1.08rem;
}

.check-list {
  display: grid;
  gap: 12px;
  padding: 0;
  margin: 24px 0 0;
  list-style: none;
}

.check-list li {
  position: relative;
  padding-left: 26px;
}

.check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 12px;
  height: 12px;
  background: var(--green);
  border-radius: 3px;
  transform: translateY(-50%);
}

.brand-photo {
  margin: 0;
}

.brand-photo img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: 8px;
}

.brand-photo figcaption {
  margin-top: 10px;
  color: var(--muted);
  font-size: 0.9rem;
}

.activity-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
}

.activity-card {
  overflow: hidden;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.activity-card img {
  width: 100%;
  aspect-ratio: 16 / 11;
  object-fit: cover;
}

.activity-card div {
  padding: 18px;
}

.activity-card h3,
.role-grid h3,
.flow h3 {
  margin: 4px 0 8px;
  font-size: 1.28rem;
}

.activity-card p,
.role-grid p,
.flow p {
  margin: 0;
  color: var(--muted);
}

.two-column {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(280px, 0.85fr);
  gap: clamp(28px, 5vw, 68px);
  align-items: start;
}

.lead {
  max-width: 720px;
  color: var(--muted);
  font-size: 1.08rem;
}

.info-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 28px;
}

.info-tile {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
}

.info-tile strong {
  display: block;
  margin: 4px 0;
  font-size: 1.42rem;
}

.info-tile p {
  margin: 0;
  color: var(--muted);
}

.flow {
  padding: 28px;
  color: var(--paper);
  background: var(--green-dark);
  border-radius: 8px;
}

.flow ol {
  display: grid;
  gap: 16px;
  padding: 0;
  margin: 20px 0 0;
  list-style: none;
}

.flow li {
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: 12px;
  align-items: center;
}

.flow li span {
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  color: var(--green-dark);
  background: var(--paper);
  border-radius: 50%;
  font-weight: 800;
}

.volunteer {
  background: var(--purple-deep);
  color: var(--paper);
}

.volunteer .section-heading p,
.volunteer .role-grid p,
.volunteer-note p {
  color: rgba(255, 255, 255, 0.78);
}

.volunteer .role-grid span {
  color: var(--amber);
}

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

.role-grid article {
  min-height: 220px;
  padding: 24px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 8px;
}

.volunteer-note {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-top: 24px;
  padding: 22px;
  background: rgba(255, 255, 255, 0.08);
  border-left: 5px solid var(--amber);
  border-radius: 8px;
}

.volunteer-note p {
  max-width: 720px;
  margin: 0;
}

.safety {
  display: grid;
  grid-template-columns: minmax(220px, 0.32fr) 1fr;
  gap: clamp(28px, 5vw, 70px);
}

.safety-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.safety-grid article {
  padding: 22px;
  background: var(--soft);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.safety-grid h3 {
  margin: 0 0 8px;
  font-size: 1.15rem;
}

.safety-grid p {
  margin: 0;
  color: var(--muted);
}

.faq {
  display: grid;
  grid-template-columns: minmax(220px, 0.32fr) 1fr;
  gap: clamp(28px, 5vw, 70px);
  background: var(--soft);
}

.faq-list {
  display: grid;
  gap: 10px;
}

details {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
}

summary {
  cursor: pointer;
  padding: 18px 20px;
  font-weight: 800;
}

details p {
  margin: 0;
  padding: 0 20px 20px;
  color: var(--muted);
}

.contact-section {
  display: grid;
  grid-template-columns: minmax(260px, 0.78fr) minmax(320px, 1fr);
  gap: clamp(28px, 5vw, 70px);
  padding: clamp(70px, 10vw, 112px) clamp(18px, 5vw, 68px);
  color: var(--paper);
  background: var(--green-dark);
}

.contact-section p {
  color: rgba(255, 255, 255, 0.78);
}

.phone {
  padding-top: 18px;
  border-top: 1px solid rgba(255, 255, 255, 0.28);
}

.phone strong {
  color: var(--paper);
  font-size: 2rem;
}

.contact-form {
  display: grid;
  gap: 14px;
  padding: 24px;
  color: var(--ink);
  background: var(--paper);
  border-radius: 8px;
}

.contact-form label {
  display: grid;
  gap: 6px;
  font-weight: 700;
}

.contact-form input,
.contact-form select,
.contact-form textarea {
  width: 100%;
  min-height: 44px;
  padding: 10px 12px;
  border: 1px solid #b8c5bd;
  border-radius: 6px;
  font: inherit;
}

.contact-form textarea {
  resize: vertical;
}

.contact-form .checkbox {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-weight: 600;
}

.contact-form .checkbox input {
  width: 18px;
  min-height: 18px;
}

.form-note,
.field-error,
.form-status {
  margin: 0;
  font-size: 0.9rem;
}

.contact-form .form-note {
  color: var(--muted);
}

.field-error {
  color: #a8324a;
  font-weight: 700;
}

.checkbox .field-error {
  flex-basis: 100%;
}

.contact-form [aria-invalid="true"] {
  border-color: #a8324a;
  box-shadow: 0 0 0 3px rgba(168, 50, 74, 0.12);
}

.form-status {
  display: grid;
  gap: 3px;
  min-height: 0;
  color: var(--green-dark);
}

.form-status span {
  color: var(--muted);
}

.contact-form button {
  min-height: 48px;
  border: 0;
  border-radius: 8px;
  color: var(--paper);
  background: var(--purple);
  font: inherit;
  font-weight: 800;
  cursor: pointer;
}

.site-footer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 14px 28px;
  align-items: center;
  padding: 30px clamp(18px, 5vw, 68px);
  background: #17212a;
  color: var(--paper);
}

.site-footer p {
  margin: 0;
}

.site-footer p:nth-child(2) {
  color: rgba(255, 255, 255, 0.68);
}

.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  grid-row: 1 / span 2;
  grid-column: 2;
}

.site-footer a {
  color: rgba(255, 255, 255, 0.82);
  text-decoration: none;
}

@media (max-width: 980px) {
  .nav {
    align-items: center;
    flex-direction: row;
    flex-wrap: wrap;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .nav-links {
    display: none;
    flex-direction: column;
    align-items: stretch;
    width: 100%;
    padding: 12px 0 2px;
    border-top: 1px solid var(--line);
  }

  .nav-links[data-open="true"] {
    display: flex;
  }

  .nav-links a {
    padding: 8px 0;
  }

  .notice-band,
  .split,
  .two-column,
  .safety,
  .faq,
  .contact-section {
    grid-template-columns: 1fr;
  }

  .activity-grid,
  .safety-grid,
  .role-grid {
    grid-template-columns: 1fr;
  }

  .volunteer-note {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-footer {
    grid-template-columns: 1fr;
  }

  .site-footer nav {
    grid-row: auto;
    grid-column: auto;
  }
}

@media (max-width: 680px) {
  .utility {
    flex-direction: column;
    gap: 4px;
  }

  .hero {
    min-height: 70vh;
    padding-top: 60px;
    background-image:
      linear-gradient(90deg, rgba(21, 36, 42, 0.88), rgba(21, 36, 42, 0.64)),
      url("assets/hero-lake.jpg");
  }

  .hero-actions,
  .section-heading {
    align-items: stretch;
    flex-direction: column;
  }

  .button {
    width: 100%;
  }

  .hero-facts,
  .info-grid,
  .news-item {
    grid-template-columns: 1fr;
  }

  .notice-band {
    margin-top: -18px;
    padding: 20px;
  }
}