:root {
  color-scheme: light;
  --ink: #17202a;
  --muted: #596575;
  --line: #d9e0ea;
  --page: #f6f7f5;
  --surface: #ffffff;
  --blue: #246bfe;
  --green: #0f766e;
  --gold: #a15c00;
  --rose: #b42357;
  --shadow: 0 18px 44px rgba(23, 32, 42, 0.1);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--page);
  color: var(--ink);
  line-height: 1.6;
}

a {
  color: var(--blue);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.18em;
}

img {
  max-width: 100%;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid rgba(217, 224, 234, 0.8);
  background: rgba(246, 247, 245, 0.92);
  backdrop-filter: blur(14px);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  min-height: 68px;
  gap: 18px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-weight: 750;
  text-decoration: none;
}

.brand img {
  width: 34px;
  height: 34px;
  border-radius: 8px;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-end;
  gap: 6px 18px;
  font-size: 0.95rem;
}

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

.nav-links a[aria-current="page"],
.nav-links a:hover {
  color: var(--ink);
}

.container {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
}

.hero {
  position: relative;
  display: block;
  padding: 56px 0 64px;
  overflow: hidden;
}

.hero > div:first-child {
  position: relative;
  z-index: 2;
  max-width: 620px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--green);
  font-size: 0.78rem;
  font-weight: 760;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.12;
  letter-spacing: 0;
}

h1 {
  max-width: 12ch;
  font-size: 5.9rem;
}

h2 {
  font-size: 3rem;
}

h3 {
  font-size: 1.15rem;
}

.lead {
  max-width: 680px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 1.25rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
  background: var(--surface);
  font-weight: 700;
  text-decoration: none;
}

.button.primary {
  border-color: var(--blue);
  background: var(--blue);
  color: #fff;
}

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

.reader {
  position: absolute;
  z-index: 1;
  top: 56px;
  right: 0;
  width: min(620px, 58%);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.reader-bar {
  display: flex;
  align-items: center;
  gap: 7px;
  height: 38px;
  padding: 0 14px;
  border-bottom: 1px solid var(--line);
  background: #eef3f1;
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 999px;
  background: #d45050;
}

.dot:nth-child(2) {
  background: #e9aa30;
}

.dot:nth-child(3) {
  background: #28a55f;
}

.reader-body {
  padding: clamp(22px, 4vw, 38px);
}

.article-label {
  margin: 0 0 12px;
  color: var(--gold);
  font-size: 0.82rem;
  font-weight: 760;
}

.jp-sample {
  margin: 0;
  color: #1b2733;
  font-family: "Hiragino Sans", "Yu Gothic", "Noto Sans JP", system-ui, sans-serif;
  font-size: 2.85rem;
  line-height: 1.78;
}

ruby {
  ruby-position: over;
}

rt {
  color: var(--blue);
  font-size: 0.48em;
  font-weight: 700;
}

.word-popover {
  width: min(100%, 420px);
  margin-top: 26px;
  border: 1px solid #bfd0e7;
  border-radius: 8px;
  background: #f8fbff;
  overflow: hidden;
}

.word-popover header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 16px;
  border-bottom: 1px solid #d7e4f6;
}

.word-popover strong {
  font-size: 1.2rem;
}

.status {
  color: var(--green);
  font-size: 0.8rem;
  font-weight: 760;
}

.word-popover p {
  margin: 0;
  padding: 14px 16px 16px;
  color: var(--muted);
}

.section {
  padding: 78px 0;
  border-top: 1px solid var(--line);
}

.section-intro {
  max-width: 720px;
}

.section-intro p {
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 1.06rem;
}

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

.card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  padding: 22px;
}

.card p,
.policy-main p,
.policy-main li {
  color: var(--muted);
}

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

.number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  margin-bottom: 14px;
  border-radius: 8px;
  background: #eaf1ff;
  color: var(--blue);
  font-weight: 800;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  gap: 34px;
  align-items: start;
}

.feature-list {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.feature-list li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 12px;
  align-items: start;
  color: var(--muted);
}

.check {
  width: 22px;
  height: 22px;
  border-radius: 999px;
  background: #e8f5f1;
  color: var(--green);
  text-align: center;
  line-height: 22px;
  font-weight: 900;
}

.page-hero {
  padding: 68px 0 44px;
}

.page-hero h1 {
  max-width: 13ch;
  font-size: 4.7rem;
}

.meta {
  margin-top: 16px;
  color: var(--muted);
}

.policy-main {
  display: grid;
  grid-template-columns: minmax(0, 250px) minmax(0, 1fr);
  gap: 42px;
  padding: 0 0 80px;
}

.toc {
  position: sticky;
  top: 92px;
  align-self: start;
  border-left: 3px solid var(--line);
  padding-left: 16px;
}

.toc a {
  display: block;
  margin: 0 0 10px;
  color: var(--muted);
  text-decoration: none;
}

.toc a:hover {
  color: var(--ink);
}

.prose {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  padding: clamp(22px, 4vw, 42px);
}

.prose section + section {
  margin-top: 36px;
  padding-top: 32px;
  border-top: 1px solid var(--line);
}

.prose h2 {
  font-size: 1.55rem;
}

.prose h3 {
  margin-top: 24px;
}

.prose ul,
.prose ol {
  padding-left: 1.3rem;
}

.callout {
  margin-top: 24px;
  border-left: 4px solid var(--green);
  background: #eef8f5;
  padding: 16px 18px;
  border-radius: 0 8px 8px 0;
}

.support-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.site-footer {
  border-top: 1px solid var(--line);
  background: #eef0ec;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 28px 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

@media (max-width: 840px) {
  .split,
  .policy-main {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: 38px;
  }

  .reader {
    top: 160px;
    right: -120px;
    width: 620px;
    opacity: 0.24;
  }

  .grid,
  .support-grid {
    grid-template-columns: 1fr;
  }

  .toc {
    position: static;
  }

  h1 {
    font-size: 4.2rem;
  }

  h2 {
    font-size: 2.35rem;
  }

  .lead {
    font-size: 1.15rem;
  }

  .jp-sample {
    font-size: 2.3rem;
  }

  .page-hero h1 {
    font-size: 3.5rem;
  }
}

@media (max-width: 600px) {
  .nav {
    align-items: flex-start;
    flex-direction: column;
    padding: 14px 0;
  }

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

  .page-hero,
  .section {
    padding-top: 48px;
    padding-bottom: 48px;
  }

  .hero-actions,
  .button {
    width: 100%;
  }

  .hero {
    padding-bottom: 52px;
  }

  .reader {
    top: 310px;
    right: -180px;
    width: 600px;
    opacity: 0.1;
  }

  h1,
  .page-hero h1 {
    font-size: 3rem;
  }

  h2 {
    font-size: 2rem;
  }

  .jp-sample {
    font-size: 1.7rem;
  }
}