:root {
  --bg: #f7efe1;
  --paper: #fffaf2;
  --paper-strong: #fff5e7;
  --ink: #10213e;
  --ink-soft: rgba(16, 33, 62, 0.74);
  --line: rgba(16, 33, 62, 0.14);
  --coral: #eb715f;
  --coral-soft: rgba(235, 113, 95, 0.16);
  --sky: #cad6eb;
  --shadow: 0 28px 70px rgba(16, 33, 62, 0.14);
  --radius-xl: 32px;
  --radius-lg: 24px;
  --radius-md: 18px;
  --content-width: min(1180px, calc(100vw - 40px));
  --display-font: "Noto Serif SC", "Songti SC", "Source Han Serif SC", serif;
  --body-font: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  background:
    radial-gradient(circle at top left, rgba(235, 113, 95, 0.18), transparent 28%),
    radial-gradient(circle at 85% 14%, rgba(202, 214, 235, 0.8), transparent 22%),
    linear-gradient(180deg, #f6efe4 0%, #fcf7ef 48%, #f7efe1 100%);
  color: var(--ink);
  font-family: var(--body-font);
  line-height: 1.65;
}

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

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

p,
dl,
dd,
dt {
  margin: 0;
}

.skip-link {
  position: absolute;
  left: 16px;
  top: -48px;
  z-index: 50;
  padding: 12px 16px;
  border-radius: 999px;
  background: var(--ink);
  color: #fff;
  transition: top 180ms ease;
}

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

.page-shell {
  width: var(--content-width);
  margin: 0 auto;
  padding: 20px 0 48px;
}

.site-header {
  position: sticky;
  top: 14px;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 24px;
  padding: 16px 18px;
  border: 1px solid rgba(255, 255, 255, 0.62);
  border-radius: 24px;
  background: rgba(255, 250, 242, 0.78);
  backdrop-filter: blur(18px);
  box-shadow: 0 18px 50px rgba(16, 33, 62, 0.08);
}

.brand {
  flex: 0 0 auto;
}

.brand img {
  width: min(280px, 48vw);
  height: auto;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 10px;
}

.site-nav a {
  padding: 10px 14px;
  border-radius: 999px;
  color: var(--ink-soft);
  font-size: 0.96rem;
  transition:
    background-color 160ms ease,
    color 160ms ease,
    transform 160ms ease;
}

.site-nav a:hover,
.site-nav a:focus-visible,
.site-nav a.is-active {
  background: var(--ink);
  color: #fff;
  transform: translateY(-1px);
}

.section {
  position: relative;
  margin-top: 26px;
  padding: 34px;
  border: 1px solid rgba(255, 255, 255, 0.58);
  border-radius: var(--radius-xl);
  background: rgba(255, 250, 242, 0.8);
  box-shadow: var(--shadow);
  overflow: clip;
}

.section::before {
  content: "";
  position: absolute;
  inset: auto -20% -70% auto;
  width: 280px;
  height: 280px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(235, 113, 95, 0.16), transparent 68%);
  pointer-events: none;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(320px, 0.9fr);
  align-items: center;
  gap: 32px;
  padding-top: 44px;
  padding-bottom: 42px;
}

.eyebrow {
  margin-bottom: 14px;
  color: var(--coral);
  font-size: 0.84rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

h1,
h2,
h3,
summary {
  margin: 0;
  color: var(--ink);
}

h1,
h2 {
  font-family: var(--display-font);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.03em;
}

h1 {
  font-size: clamp(3.4rem, 7vw, 5.8rem);
}

h2 {
  max-width: 14ch;
  font-size: clamp(2rem, 4vw, 3.2rem);
}

h3 {
  font-size: 1.2rem;
}

.hero-dek,
.section-heading p + h2 + p,
.intro-grid p,
.relationship-copy p,
.guide-cards p,
.guide-note p,
.faq-items p,
.character-card p {
  color: var(--ink-soft);
}

.hero-dek {
  max-width: 60ch;
  font-size: 1.06rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 18px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-weight: 700;
  transition:
    transform 160ms ease,
    box-shadow 160ms ease,
    background-color 160ms ease;
}

.button:hover,
.button:focus-visible {
  transform: translateY(-1px);
}

.button-primary {
  background: var(--ink);
  color: #fff;
  box-shadow: 0 14px 30px rgba(16, 33, 62, 0.18);
}

.button-secondary {
  border-color: var(--line);
  background: rgba(255, 255, 255, 0.68);
}

.hero-note {
  margin-top: 18px;
  max-width: 52ch;
  color: var(--ink-soft);
  font-size: 0.95rem;
}

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

.hero-stats div,
.intro-points article,
.character-card,
.relationship-copy article,
.guide-cards article,
.faq-items details {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.66);
}

.hero-stats div {
  padding: 16px 18px;
}

.hero-stats dt {
  margin-bottom: 6px;
  color: var(--ink-soft);
  font-size: 0.82rem;
}

.hero-stats dd {
  font-family: var(--display-font);
  font-size: 1.06rem;
}

.hero-visual {
  display: flex;
  justify-content: center;
}

.hero-art-shell {
  position: relative;
  display: grid;
  place-items: center;
  width: min(100%, 510px);
  aspect-ratio: 1 / 1;
  border: 1px solid rgba(16, 33, 62, 0.12);
  border-radius: 34px;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.95), rgba(249, 238, 222, 0.9)),
    linear-gradient(180deg, rgba(235, 113, 95, 0.1), transparent 70%);
  overflow: hidden;
}

.hero-art-shell::before,
.hero-art-shell::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  border: 1px solid rgba(16, 33, 62, 0.14);
}

.hero-art-shell::before {
  inset: 7%;
}

.hero-art-shell::after {
  inset: 15%;
}

.hero-art-shell img {
  position: relative;
  z-index: 2;
  width: min(72%, 360px);
  filter: drop-shadow(0 20px 40px rgba(16, 33, 62, 0.16));
}

.hero-orbit {
  position: absolute;
  border-radius: 999px;
  border: 1px solid rgba(235, 113, 95, 0.28);
}

.hero-orbit-a {
  width: 94%;
  height: 60%;
  transform: rotate(12deg);
}

.hero-orbit-b {
  width: 76%;
  height: 84%;
  transform: rotate(-18deg);
}

.hero-caption {
  position: absolute;
  inset: auto 24px 22px 24px;
  z-index: 2;
  display: flex;
  justify-content: space-between;
  gap: 10px;
  color: var(--ink-soft);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.section-heading {
  display: grid;
  gap: 10px;
}

.intro-card {
  background:
    linear-gradient(180deg, rgba(255, 250, 242, 0.9), rgba(255, 245, 231, 0.92)),
    radial-gradient(circle at top right, rgba(202, 214, 235, 0.35), transparent 30%);
}

.intro-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.95fr);
  gap: 24px;
  margin-top: 26px;
}

.intro-grid > div:first-child {
  display: grid;
  gap: 18px;
}

.intro-points {
  display: grid;
  gap: 14px;
}

.intro-points article,
.relationship-copy article,
.guide-cards article,
.faq-items details {
  padding: 22px;
}

.character-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin-top: 28px;
}

.character-card {
  position: relative;
  min-height: 200px;
  padding: 26px 22px 22px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.84), rgba(255, 244, 231, 0.92)),
    radial-gradient(circle at top right, rgba(235, 113, 95, 0.16), transparent 34%);
}

.character-index {
  display: inline-flex;
  margin-bottom: 12px;
  color: var(--coral);
  font-size: 0.86rem;
  font-weight: 700;
  letter-spacing: 0.16em;
}

.relationship-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(320px, 1.05fr);
  gap: 24px;
  margin-top: 28px;
}

.relationship-map {
  position: relative;
  min-height: 520px;
  border: 1px solid var(--line);
  border-radius: 28px;
  background:
    radial-gradient(circle at center, rgba(202, 214, 235, 0.28), transparent 45%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.92), rgba(255, 245, 231, 0.88));
  overflow: hidden;
}

.relationship-map::before {
  content: "";
  position: absolute;
  inset: 10% 8%;
  border: 1px dashed rgba(16, 33, 62, 0.12);
  border-radius: 999px;
}

.node {
  position: absolute;
  display: grid;
  place-items: center;
  min-width: 92px;
  min-height: 92px;
  padding: 12px;
  border-radius: 50%;
  border: 1px solid rgba(16, 33, 62, 0.15);
  background: rgba(255, 255, 255, 0.92);
  box-shadow: 0 14px 30px rgba(16, 33, 62, 0.08);
  font-family: var(--display-font);
}

.node-core {
  min-width: 132px;
  min-height: 132px;
  background: var(--ink);
  color: #fff;
}

.node-kazuya {
  left: 14%;
  top: 40%;
}

.node-chizuru {
  right: 14%;
  top: 18%;
}

.node-mami {
  left: 10%;
  top: 14%;
}

.node-ruka {
  right: 14%;
  bottom: 14%;
}

.node-sumi {
  left: 26%;
  bottom: 12%;
}

.node-mini {
  right: 30%;
  top: 58%;
}

.link {
  position: absolute;
  height: 2px;
  transform-origin: left center;
  border-radius: 999px;
}

.link-main {
  left: 34%;
  top: 48%;
  width: 32%;
  background: linear-gradient(90deg, rgba(235, 113, 95, 0.92), rgba(16, 33, 62, 0.92));
  transform: rotate(-18deg);
}

.link-mami {
  left: 22%;
  top: 28%;
  width: 18%;
  background: rgba(16, 33, 62, 0.28);
  transform: rotate(44deg);
}

.link-ruka {
  left: 58%;
  top: 54%;
  width: 18%;
  background: rgba(235, 113, 95, 0.36);
  transform: rotate(58deg);
}

.link-sumi {
  left: 34%;
  top: 60%;
  width: 16%;
  background: rgba(16, 33, 62, 0.24);
  transform: rotate(104deg);
}

.link-mini {
  left: 54%;
  top: 52%;
  width: 10%;
  background: rgba(16, 33, 62, 0.2);
  transform: rotate(18deg);
}

.relationship-copy {
  display: grid;
  gap: 14px;
  align-content: start;
}

.guide-grid .section-heading,
.faq-list .section-heading {
  margin-bottom: 26px;
}

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

.guide-cards article {
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.88), rgba(255, 245, 231, 0.96)),
    radial-gradient(circle at top right, rgba(202, 214, 235, 0.24), transparent 28%);
}

.guide-cards span {
  display: inline-flex;
  margin-bottom: 14px;
  color: var(--coral);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.guide-note {
  display: grid;
  gap: 10px;
  margin-top: 18px;
  padding: 18px 20px;
  border-radius: var(--radius-md);
  background: rgba(16, 33, 62, 0.04);
}

.faq-items {
  display: grid;
  gap: 14px;
}

.faq-items summary {
  cursor: pointer;
  list-style: none;
  padding-right: 28px;
  font-size: 1.05rem;
  font-weight: 700;
}

.faq-items summary::-webkit-details-marker {
  display: none;
}

.faq-items summary::after {
  content: "+";
  position: absolute;
  right: 22px;
  top: 18px;
  color: var(--coral);
  font-size: 1.4rem;
  line-height: 1;
}

.faq-items details[open] summary::after {
  content: "−";
}

.faq-items details {
  position: relative;
}

.faq-items p {
  margin-top: 14px;
}

.site-footer {
  display: grid;
  gap: 6px;
  margin: 20px 0 0;
  padding: 24px 8px 0;
  color: var(--ink-soft);
  font-size: 0.92rem;
}

[data-reveal] {
  opacity: 0;
  transform: translateY(22px);
  transition:
    opacity 520ms ease,
    transform 520ms ease;
}

[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(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;
    scroll-behavior: auto !important;
  }

  [data-reveal] {
    opacity: 1;
    transform: none;
  }
}

@media (max-width: 980px) {
  .site-header,
  .hero,
  .intro-grid,
  .relationship-layout {
    grid-template-columns: 1fr;
  }

  .site-header {
    position: static;
    flex-direction: column;
    align-items: stretch;
  }

  .site-nav {
    justify-content: flex-start;
  }

  .character-grid,
  .guide-cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .hero-art-shell {
    max-width: 560px;
    margin-inline: auto;
  }
}

@media (max-width: 720px) {
  .page-shell {
    width: min(calc(100vw - 24px), 100%);
    padding-top: 12px;
  }

  .section {
    padding: 24px 18px;
    border-radius: 24px;
  }

  h1 {
    font-size: clamp(2.7rem, 15vw, 4.3rem);
  }

  h2 {
    max-width: none;
    font-size: clamp(1.8rem, 8vw, 2.5rem);
  }

  .hero-stats,
  .character-grid,
  .guide-cards {
    grid-template-columns: 1fr;
  }

  .relationship-map {
    min-height: 430px;
  }

  .node {
    min-width: 74px;
    min-height: 74px;
    font-size: 0.92rem;
  }

  .node-core {
    min-width: 110px;
    min-height: 110px;
  }

  .node-kazuya {
    left: 8%;
    top: 44%;
  }

  .node-chizuru {
    right: 8%;
    top: 12%;
  }

  .node-mami {
    left: 10%;
    top: 12%;
  }

  .node-ruka {
    right: 8%;
    bottom: 10%;
  }

  .node-sumi {
    left: 22%;
    bottom: 10%;
  }

  .node-mini {
    right: 28%;
    top: 60%;
  }

  .link-main {
    left: 29%;
    top: 49%;
    width: 42%;
  }

  .link-mami {
    left: 20%;
    top: 28%;
    width: 18%;
  }

  .link-ruka {
    left: 55%;
    top: 58%;
    width: 20%;
  }

  .link-sumi {
    left: 33%;
    top: 63%;
  }

  .hero-caption {
    inset-inline: 18px;
    font-size: 0.72rem;
  }
}