:root {
  color-scheme: light;
  --bg: #f5f6f8;
  --surface: #ffffff;
  --surface-muted: #f9fafb;
  --text: #1b1f24;
  --text-muted: #5f6b76;
  --border: #e2e8f0;
  --accent: #1f6feb;
  --shadow: 0 16px 40px rgba(15, 23, 42, 0.06);
  --radius: 18px;
  --max-width: 920px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: linear-gradient(180deg, #ffffff 0%, var(--bg) 100%);
  color: var(--text);
  line-height: 1.7;
}

body[data-current-lang="ja"] {
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", "Segoe UI", sans-serif;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

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

.language-switcher {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  padding-top: 20px;
}

.language-button {
  min-height: 38px;
  padding: 0 14px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text-muted);
  font: inherit;
  cursor: pointer;
}

.language-button.is-active {
  border-color: var(--accent);
  color: var(--accent);
  background: #eff6ff;
}

.hero {
  padding: 72px 0 40px;
}

.hero-simple {
  padding-top: 32px;
}

.eyebrow,
.section-label,
.app-label {
  margin: 0 0 8px;
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}

h1,
h2,
h3,
.hero-subtitle,
.app-name-ja {
  margin: 0;
}

h1 {
  font-size: clamp(2.4rem, 6vw, 4rem);
  line-height: 1.05;
}

.hero-subtitle {
  margin-top: 10px;
  font-size: 1.05rem;
  color: var(--text-muted);
}

.hero-meta {
  margin: 12px 0 0;
}

.subtle-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.subtle-link:hover {
  color: var(--text);
  text-decoration: none;
}

.subtle-link-icon {
  width: 18px;
  height: 18px;
  fill: currentColor;
  flex: 0 0 auto;
}

.hero-text {
  max-width: 620px;
  margin: 22px 0 0;
  font-size: 1rem;
  color: var(--text-muted);
}

.section {
  padding: 20px 0 28px;
}

.section-heading {
  margin-bottom: 16px;
}

h2 {
  font-size: 1.6rem;
}

.panel,
.app-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.panel {
  padding: 24px;
}

.panel p,
.app-card p {
  margin: 0;
}

.panel p + p,
.app-card-body p + p {
  margin-top: 12px;
}

.apps-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.app-card {
  padding: 24px;
}

.app-card-header {
  margin-bottom: 18px;
}

h3 {
  font-size: 1.35rem;
}

.app-name-ja {
  margin-top: 6px;
  color: var(--text-muted);
}

[data-lang-content][hidden] {
  display: none !important;
}

.app-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

.app-links a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 14px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface-muted);
  color: var(--text);
}

.app-links a:hover {
  text-decoration: none;
  border-color: var(--accent);
}

.back-link {
  margin: 0;
}

.feature-list {
  margin: 0;
  padding-left: 1.2rem;
}

.feature-list li + li {
  margin-top: 10px;
}

@media (max-width: 640px) {
  .language-switcher {
    justify-content: flex-start;
    padding-top: 16px;
  }

  .hero {
    padding: 56px 0 28px;
  }

  .panel,
  .app-card {
    padding: 20px;
  }
}