:root {
  --color-bg: #fff9ec;
  --color-text: #333638;
  --color-muted: #62686b;
  --color-accent: #8bd4dd;
  --color-accent-strong: #257b87;
  --color-line: #d9ecee;
  --color-panel: #fffff8;
}

* {
  box-sizing: border-box;
}

html {
  font-size: 16px;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: Helvetica, Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Yu Gothic", "Meiryo", sans-serif;
  line-height: 1.75;
}

a {
  color: var(--color-accent-strong);
  font-weight: 700;
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.22em;
}

a:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 4px;
  border-radius: 4px;
}

.page-shell {
  width: min(100% - 32px, 800px);
  margin: 0 auto;
  padding: 34px 0 44px;
}

.hero {
  padding: 26px 0 30px;
  text-align: center;
}

.hero-compact {
  padding-bottom: 18px;
}

.app-icon {
  display: block;
  width: clamp(80px, 24vw, 96px);
  height: auto;
  aspect-ratio: 1 / 1;
  margin: 0 auto 18px;
  overflow: hidden;
  border: 1px solid var(--color-line);
  border-radius: 20px;
  background:
    linear-gradient(135deg, rgba(139, 212, 221, 0.36), rgba(255, 255, 248, 0.92)),
    var(--color-panel);
  object-fit: cover;
}

.app-label {
  margin: 0 0 6px;
  color: var(--color-accent-strong);
  font-size: 0.95rem;
  font-weight: 700;
}

h1,
h2,
h3,
p,
ol,
ul,
dl {
  margin-top: 0;
}

h1 {
  margin-bottom: 10px;
  font-size: clamp(2.1rem, 11vw, 3.7rem);
  line-height: 1.1;
  letter-spacing: 0;
}

.hero-compact h1 {
  font-size: clamp(2rem, 9vw, 3.1rem);
}

.tagline {
  margin-bottom: 0;
  color: var(--color-muted);
  font-size: 1.1rem;
  line-height: 1.5;
}

.section {
  padding: 28px 0;
  border-top: 1px solid var(--color-line);
}

.section h2 {
  margin-bottom: 18px;
  color: var(--color-accent-strong);
  font-size: clamp(1.45rem, 5vw, 2rem);
  line-height: 1.25;
}

.language-block {
  padding: 18px 0 4px;
}

.language-block + .language-block {
  margin-top: 14px;
  border-top: 1px dashed var(--color-line);
}

.language-block h3 {
  display: inline-block;
  margin-bottom: 12px;
  padding: 4px 10px;
  border: 1px solid var(--color-line);
  border-radius: 8px;
  background: var(--color-panel);
  color: var(--color-muted);
  font-size: 0.98rem;
  line-height: 1.35;
}

p {
  margin-bottom: 1rem;
  font-size: 1.03rem;
}

ol,
ul {
  padding-left: 1.45rem;
}

li {
  margin-bottom: 0.58rem;
  padding-left: 0.1rem;
}

.feature-list {
  display: grid;
  gap: 10px;
  padding-left: 0;
  list-style: none;
}

.feature-list li {
  position: relative;
  margin: 0;
  padding: 12px 14px 12px 36px;
  border: 1px solid var(--color-line);
  border-radius: 8px;
  background: rgba(255, 255, 248, 0.62);
}

.feature-list li::before {
  content: "";
  position: absolute;
  top: 1.25rem;
  left: 15px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--color-accent);
}

.faq-list {
  margin-bottom: 0;
}

.faq-list dt {
  margin-top: 18px;
  color: var(--color-text);
  font-weight: 700;
}

.faq-list dt:first-child {
  margin-top: 0;
}

.faq-list dd {
  margin: 6px 0 0;
  color: var(--color-muted);
}

.contact-section {
  font-size: 1.03rem;
}

.footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  padding: 28px 0 6px;
  border-top: 1px solid var(--color-line);
  text-align: center;
}

.footer a {
  display: inline-block;
  padding: 10px 14px;
  border: 1px solid var(--color-line);
  border-radius: 8px;
  background: var(--color-panel);
}

@media (min-width: 720px) {
  .page-shell {
    padding-top: 48px;
    padding-bottom: 64px;
  }

  .hero {
    padding-top: 34px;
    padding-bottom: 42px;
  }

  .app-icon {
    width: 112px;
  }

  .section {
    padding: 34px 0;
  }

  .language-block {
    padding-right: 24px;
    padding-left: 24px;
  }
}