:root {
  --page-bg: #071321;
  --panel-bg: rgba(8, 19, 33, 0.7);
  --panel-line: rgba(255, 241, 220, 0.18);
  --panel-text: rgba(255, 245, 232, 0.94);
  --panel-accent: #ffc971;
  --poster-image: url("assets/poster-design-natsumatsuri-v2.png");
  --poster-width: 1024;
  --poster-height: 1536;
  --header-gap: 16px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Inter", "Noto Sans JP", "Hiragino Sans", "Yu Gothic", system-ui, sans-serif;
  background:
    radial-gradient(circle at top, rgba(255, 158, 62, 0.14), transparent 20%),
    linear-gradient(180deg, #0a1624 0%, #071321 100%);
  color: #fff;
}

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

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

.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;
}

.skip-link {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 30;
  padding: 0.7rem 0.95rem;
  border-radius: 999px;
  background: #fff5e8;
  color: #0a1624;
  opacity: 0;
  transform: translate(-120%, -120%);
  transition: transform 180ms ease;
}

.skip-link:focus-visible {
  opacity: 1;
  transform: translate(12px, 12px);
}

.floating-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  width: min(1120px, calc(100% - 24px));
  margin: 14px auto 0;
  padding: 12px 14px;
  border: 1px solid var(--panel-line);
  border-radius: 999px;
  background: rgba(8, 19, 33, 0.84);
  backdrop-filter: blur(14px);
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.22);
}

.brand-chip {
  font-family: "Fraunces", serif;
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--panel-accent);
  white-space: nowrap;
}

.floating-nav {
  display: flex;
  align-items: center;
  gap: 18px;
  color: var(--panel-text);
  font-size: 0.92rem;
  font-weight: 600;
}

.floating-nav a {
  position: relative;
  padding: 0.35rem 0;
  opacity: 0.8;
  transition: opacity 180ms ease;
}

.floating-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 2px;
  transform: scaleX(0);
  transform-origin: center;
  background: linear-gradient(90deg, transparent, var(--panel-accent), transparent);
  transition: transform 180ms ease;
}

.floating-nav a:hover,
.floating-nav a.is-active {
  opacity: 1;
}

.floating-nav a:hover::after,
.floating-nav a.is-active::after {
  transform: scaleX(1);
}

.poster-page {
  width: min(1024px, calc(100% - 24px));
  margin: 18px auto 40px;
  border-radius: 30px;
  overflow: hidden;
  box-shadow:
    0 24px 64px rgba(0, 0, 0, 0.38),
    0 0 0 1px rgba(255, 241, 220, 0.08);
  background: #0d1726;
}

.poster-section {
  position: relative;
  overflow: hidden;
  isolation: isolate;
  scroll-margin-top: 84px;
}

.poster-section::before {
  content: "";
  display: block;
  padding-top: calc(var(--slice-height) / var(--poster-width) * 100%);
}

.poster-frame {
  position: absolute;
  inset: 0;
}

.poster-frame img {
  position: absolute;
  inset: 0 auto auto 0;
  width: 100%;
  max-width: none;
  height: auto;
  transform: translateY(calc(var(--slice-offset) / var(--poster-height) * -100%));
  user-select: none;
  pointer-events: none;
}

.poster-section + .poster-section {
  box-shadow: inset 0 1px 0 rgba(255, 241, 220, 0.03);
}

.contact-section::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(6, 11, 18, 0.03) 0%, rgba(6, 11, 18, 0.08) 100%);
  pointer-events: none;
}

.hotspot-layer {
  position: absolute;
  inset: 0;
  z-index: 2;
}

.hotspot {
  position: absolute;
  border-radius: 18px;
  outline: 1px solid transparent;
  transition: outline-color 180ms ease, background-color 180ms ease, transform 180ms ease;
}

.hotspot:hover,
.hotspot:focus-visible {
  outline-color: rgba(255, 201, 113, 0.85);
  background: rgba(255, 201, 113, 0.08);
  transform: translateY(-2px);
}

.action-visit {
  left: 30.5%;
  top: 10%;
  width: 14.5%;
  height: 42%;
}

.action-support {
  left: 45%;
  top: 10%;
  width: 14.8%;
  height: 42%;
}

.action-request {
  left: 59.9%;
  top: 10%;
  width: 14%;
  height: 42%;
}

.contact-phone {
  left: 81.7%;
  top: 35.8%;
  width: 11.6%;
  height: 8.8%;
  border-radius: 10px;
}

.contact-mail {
  left: 80.8%;
  top: 46.5%;
  width: 17%;
  height: 8.3%;
  border-radius: 10px;
}

.contact-site {
  left: 77.2%;
  top: 61.7%;
  width: 18.8%;
  height: 13.2%;
  border-radius: 999px;
}

.mobile-content {
  display: none;
}

@media (max-width: 860px) {
  body {
    padding-bottom: 0;
    background: #071321;
  }

  .floating-header {
    position: sticky;
    top: 0;
    right: auto;
    bottom: auto;
    left: auto;
    width: auto;
    margin: 0;
    justify-content: center;
    padding: 10px 14px;
    border-width: 0 0 1px;
    border-radius: 0;
    background: rgba(8, 19, 33, 0.92);
  }

  .brand-chip {
    display: none;
  }

  .floating-nav {
    justify-content: flex-start;
    flex-wrap: nowrap;
    gap: 18px;
    overflow-x: auto;
    -ms-overflow-style: none;
    scrollbar-width: none;
    font-size: 0.9rem;
  }

  .floating-nav::-webkit-scrollbar {
    display: none;
  }

  .floating-nav a {
    min-width: max-content;
    white-space: nowrap;
  }

  .poster-page {
    width: 100%;
    margin: 0;
    border-radius: 0;
    box-shadow: none;
  }

  .poster-section {
    scroll-margin-top: 18px;
  }

  .poster-section:not(#hero) {
    overflow: visible;
    background: #fff6e9;
  }

  .poster-section:not(#hero)::before,
  .poster-section:not(#hero) .poster-frame,
  .poster-section:not(#hero) .hotspot-layer,
  .contact-section::after {
    display: none;
  }

  .poster-section + .poster-section {
    box-shadow: none;
  }

  .mobile-content {
    display: block;
    position: relative;
    z-index: 1;
    overflow: hidden;
    padding: 34px 20px 38px;
    color: #1f1a15;
    background: #fff6e9;
  }

  .mobile-content::before {
    content: "";
    display: block;
    height: clamp(190px, 40vw, 320px);
    margin: -34px -20px 28px;
    background-image:
      linear-gradient(180deg, rgba(7, 19, 33, 0.08), rgba(7, 19, 33, 0.18)),
      var(--poster-image);
    background-repeat: no-repeat;
    background-size: 100vw auto;
  }

  .mobile-content h2 {
    margin: 0 0 14px;
    font-family: "Yu Mincho", "Hiragino Mincho ProN", serif;
    font-size: 1.75rem;
    line-height: 1.25;
    color: #172031;
  }

  .mobile-content h3 {
    margin: 0 0 8px;
    font-family: "Yu Mincho", "Hiragino Mincho ProN", serif;
    font-size: 1.06rem;
    line-height: 1.35;
    color: #172031;
  }

  .mobile-content p,
  .mobile-content address,
  .mobile-content li {
    margin: 0;
    font-size: 0.98rem;
    line-height: 1.85;
    color: #3f352a;
    font-style: normal;
  }

  .mobile-content p + p {
    margin-top: 12px;
  }

  .section-kicker {
    margin-bottom: 8px;
    color: #b05f16;
    font-size: 0.76rem;
    font-weight: 800;
    letter-spacing: 0.12em;
    text-transform: uppercase;
  }

  .dark-content {
    color: #fff6e9;
    background:
      linear-gradient(180deg, rgba(7, 19, 33, 0.62), rgba(7, 19, 33, 0.96) 38%, rgba(9, 30, 52, 0.98)),
      var(--poster-image),
      #071321;
    background-repeat: no-repeat;
    background-size: auto, 100vw auto, auto;
    background-position: center, center -60.9vw, center;
    padding-top: clamp(150px, 48vw, 330px);
  }

  .dark-content::before,
  .contact-content::before {
    display: none;
  }

  .dark-content h2,
  .dark-content h3,
  .dark-content p {
    color: #fff6e9;
  }

  .dark-content .section-kicker {
    color: #ffc971;
  }

  .rhythm-content,
  .contact-content {
    background: #f3eadb;
  }

  .intro-content::before {
    background-position: center, center -35.7vw;
  }

  .rhythm-content::before {
    background-position: center, center -80.8vw;
  }

  .activities-content::before {
    background-position: center, center -103vw;
  }

  .contact-content {
    padding-top: clamp(170px, 50vw, 340px);
    padding-bottom: 132px;
    color: #fff6e9;
    background:
      linear-gradient(180deg, rgba(7, 19, 33, 0.38), rgba(7, 19, 33, 0.92) 42%, rgba(7, 19, 33, 0.98)),
      var(--poster-image),
      #071321;
    background-repeat: no-repeat;
    background-size: auto, 100vw auto, auto;
    background-position: center, center -124.4vw, center;
  }

  .contact-content h2,
  .contact-content p,
  .contact-content address {
    color: #fff6e9;
    text-shadow: 0 2px 12px rgba(0, 0, 0, 0.36);
  }

  .contact-content .section-kicker {
    color: #ffc971;
  }

  .activities-content {
    background: #fffaf1;
  }

  .mobile-card-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 14px;
    margin-top: 20px;
  }

  .mobile-card-grid article {
    padding-top: 14px;
    border-top: 1px solid rgba(31, 26, 21, 0.14);
  }

  .dark-content .mobile-card-grid article {
    min-height: 132px;
    padding: 76px 12px 14px;
    border: 1px solid rgba(255, 246, 233, 0.16);
    border-radius: 8px;
    background-image:
      linear-gradient(180deg, rgba(7, 19, 33, 0.1), rgba(7, 19, 33, 0.84) 58%, rgba(7, 19, 33, 0.94)),
      var(--poster-image);
    background-repeat: no-repeat;
    background-size: auto, 760px auto;
    box-shadow: 0 16px 34px rgba(0, 0, 0, 0.18);
  }

  .dark-content .mobile-card-grid article:nth-child(1) {
    background-position: center, 34% -468px;
  }

  .dark-content .mobile-card-grid article:nth-child(2) {
    background-position: center, 48% -468px;
  }

  .dark-content .mobile-card-grid article:nth-child(3) {
    background-position: center, 66% -468px;
  }

  .dark-content .mobile-card-grid article:nth-child(4) {
    background-position: center, 84% -468px;
  }

  .step-list {
    display: grid;
    gap: 16px;
    padding: 0;
    margin: 22px 0 0;
    list-style: none;
  }

  .step-list li {
    display: block;
    min-height: 150px;
    padding: 82px 16px 16px;
    border: 0;
    border-radius: 8px;
    background-image:
      linear-gradient(180deg, rgba(255, 246, 233, 0.06), rgba(255, 246, 233, 0.7) 50%, rgba(255, 246, 233, 0.96)),
      var(--poster-image);
    background-repeat: no-repeat;
    background-size: auto, 780px auto;
    box-shadow: inset 0 0 0 1px rgba(31, 26, 21, 0.12);
  }

  .step-list li:nth-child(1) {
    background-position: center, 34% -630px;
  }

  .step-list li:nth-child(2) {
    background-position: center, 58% -630px;
  }

  .step-list li:nth-child(3) {
    background-position: center, 82% -630px;
  }

  .step-list strong {
    display: block;
    white-space: nowrap;
    color: #172031;
    font-family: "Yu Mincho", "Hiragino Mincho ProN", serif;
    font-size: 1.18rem;
    line-height: 1.35;
  }

  .step-list span {
    display: block;
  }

  .contact-buttons {
    display: grid;
    gap: 10px;
    margin-top: 88px;
  }

  .contact-buttons a {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 12px 16px;
    border-radius: 8px;
    background: #0f243c;
    color: #fff6e9;
    font-weight: 800;
  }

  .contact-phone {
    left: 80.4%;
    top: 34.7%;
    width: 14.7%;
    height: 11.2%;
  }

  .contact-mail {
    left: 79.4%;
    top: 45.4%;
    width: 18.9%;
    height: 10.4%;
  }

  .contact-site {
    left: 75.8%;
    top: 60.3%;
    width: 21.7%;
    height: 15.8%;
  }
}

@media (max-width: 640px) {
  .floating-header {
    padding: 9px 10px;
  }

  .floating-nav {
    font-size: 0.82rem;
    gap: 16px;
  }

  .hotspot:hover,
  .hotspot:focus-visible {
    transform: none;
  }

  .poster-section {
    scroll-margin-top: 20px;
  }

  .mobile-content {
    padding: 30px 18px;
  }

  .mobile-content h2 {
    font-size: 1.55rem;
  }

  .mobile-content p,
  .mobile-content address,
  .mobile-content li {
    font-size: 0.94rem;
  }
}

@media (max-width: 860px) {
  #hero::before {
    padding-top: 58vw;
  }

  #hero .poster-frame::after {
    content: "";
    position: absolute;
    inset: auto 0 0;
    height: 38%;
    background: linear-gradient(180deg, rgba(7, 19, 33, 0), rgba(7, 19, 33, 0.5));
    pointer-events: none;
  }

  .mobile-content {
    overflow: hidden;
    padding: 26px 18px 34px;
    background:
      radial-gradient(circle at 14% 0%, rgba(202, 117, 36, 0.08), transparent 32%),
      linear-gradient(180deg, #fff9ef, #f4ead9);
  }

  .mobile-content::before {
    height: clamp(150px, 42vw, 260px);
    margin: 0 0 22px;
    border: 1px solid rgba(72, 46, 24, 0.18);
    border-radius: 10px;
    background-image:
      linear-gradient(180deg, rgba(7, 19, 33, 0.02), rgba(7, 19, 33, 0.12)),
      var(--poster-image);
    background-repeat: no-repeat;
    background-size: 760px auto;
    box-shadow: 0 16px 34px rgba(31, 26, 21, 0.12);
  }

  .intro-content::before {
    background-position: center, 52% -286px;
  }

  .dark-content {
    padding-top: 26px;
    background:
      radial-gradient(circle at 18% 0%, rgba(255, 201, 113, 0.12), transparent 32%),
      linear-gradient(180deg, #10213a, #071321);
  }

  .dark-content::before {
    display: block;
    border-color: rgba(255, 246, 233, 0.18);
    background-image:
      linear-gradient(180deg, rgba(7, 19, 33, 0.02), rgba(7, 19, 33, 0.22)),
      var(--poster-image);
    background-position: center, 51% -462px;
  }

  .dark-content .mobile-card-grid article {
    min-height: auto;
    padding: 14px 0 0;
    border-width: 1px 0 0;
    border-radius: 0;
    background: transparent;
    box-shadow: none;
  }

  .rhythm-content::before {
    background-position: center, 53% -630px;
  }

  .step-list li {
    min-height: auto;
    padding: 16px;
    background: rgba(255, 250, 241, 0.84);
    box-shadow: inset 0 0 0 1px rgba(31, 26, 21, 0.12);
  }

  .activities-content::before {
    background-position: center, 53% -800px;
  }

  .contact-content {
    padding-top: 26px;
    padding-bottom: 44px;
    background:
      radial-gradient(circle at 16% 0%, rgba(255, 201, 113, 0.14), transparent 30%),
      linear-gradient(180deg, #10213a, #071321);
  }

  .contact-content::before {
    display: block;
    border-color: rgba(255, 246, 233, 0.18);
    background-image:
      linear-gradient(180deg, rgba(7, 19, 33, 0.02), rgba(7, 19, 33, 0.28)),
      var(--poster-image);
    background-position: center, 53% -980px;
  }

  .contact-buttons {
    margin-top: 24px;
  }
}

@media (max-width: 640px) {
  .mobile-content {
    padding: 24px 18px 32px;
  }

  .mobile-content::before {
    height: 158px;
    background-size: 710px auto;
  }

  .intro-content::before {
    background-position: center, 52% -266px;
  }

  .dark-content::before {
    background-position: center, 51% -432px;
  }

  .rhythm-content::before {
    background-position: center, 53% -584px;
  }

  .activities-content::before {
    background-position: center, 53% -744px;
  }

  .contact-content::before {
    background-position: center, 53% -912px;
  }
}

@media (max-width: 860px) {
  :root {
    --mobile-poster-frame: 100%;
  }

  .poster-page {
    background: #071321;
  }

  .poster-section {
    overflow-x: hidden;
    overflow-y: hidden;
    background: #071321;
  }

  .poster-section:not(#hero)::before,
  #hero::before {
    display: none;
  }

  .poster-section .poster-frame,
  .poster-section:not(#hero) .poster-frame {
    display: block;
    position: relative;
    inset: auto;
    width: var(--mobile-poster-frame);
    max-width: 100%;
    aspect-ratio: var(--poster-width) / var(--slice-height);
    overflow: hidden;
  }

  .poster-section .poster-frame img {
    width: var(--mobile-poster-frame);
    max-width: 100%;
  }

  .poster-section:not(#hero) .hotspot-layer {
    display: none;
  }

  #hero .poster-frame::after {
    display: none;
  }

  .mobile-content {
    display: none;
  }

  .contact-section .mobile-content {
    display: block;
    padding: 24px 18px 34px;
    color: #fff6e9;
    background:
      radial-gradient(circle at 12% 0%, rgba(255, 201, 113, 0.16), transparent 28%),
      linear-gradient(180deg, #10213a, #071321);
  }

  .contact-section .mobile-content::before {
    display: none;
  }

  .contact-content h2,
  .contact-content p,
  .contact-content address {
    color: #fff6e9;
  }

  .contact-buttons {
    margin-top: 22px;
  }
}