:root {
  color-scheme: light dark;
  --bg: #f6f8f7;
  --surface: rgba(255, 255, 255, 0.9);
  --surface-strong: #ffffff;
  --text: #18211d;
  --muted: #68736d;
  --line: #dfe7e2;
  --accent: #18a66a;
  --accent-dark: #08794a;
  --accent-soft: #e6f8ef;
  --warning: #fff7dd;
  --shadow: 0 18px 45px rgba(23, 73, 49, 0.1);
  --radius: 24px;
  --max-width: 980px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", "Meiryo", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 12% 0%, rgba(97, 229, 164, 0.2), transparent 34rem),
    linear-gradient(180deg, #f7fbf9 0%, var(--bg) 100%);
  line-height: 1.8;
}

a {
  color: var(--accent-dark);
  text-underline-offset: 0.2em;
}

a:hover { opacity: 0.78; }

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid rgba(223, 231, 226, 0.75);
  background: rgba(247, 251, 249, 0.82);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.nav {
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 800;
  text-decoration: none;
}

.brand-icon {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: linear-gradient(145deg, #4add96, #0c9e5f);
  box-shadow: 0 8px 20px rgba(16, 157, 94, 0.25);
  font-size: 20px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 18px;
  font-size: 0.94rem;
}

.nav-links a {
  color: var(--muted);
  text-decoration: none;
  font-weight: 700;
}

.hero {
  padding: 88px 0 58px;
  text-align: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  padding: 7px 13px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-dark);
  font-size: 0.85rem;
  font-weight: 800;
  letter-spacing: 0.04em;
}

h1, h2, h3 { line-height: 1.35; }

h1 {
  margin: 20px 0 14px;
  font-size: clamp(2.3rem, 8vw, 4.6rem);
  letter-spacing: -0.04em;
}

.hero p {
  max-width: 700px;
  margin: 0 auto;
  color: var(--muted);
  font-size: clamp(1rem, 2.6vw, 1.2rem);
}

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

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 20px;
  border-radius: 14px;
  background: var(--accent);
  color: #fff;
  font-weight: 800;
  text-decoration: none;
  box-shadow: 0 10px 26px rgba(24, 166, 106, 0.22);
}

.button.secondary {
  background: var(--surface-strong);
  color: var(--accent-dark);
  border: 1px solid var(--line);
  box-shadow: none;
}

main { padding-bottom: 72px; }

.section {
  margin: 24px 0;
  padding: clamp(24px, 5vw, 42px);
  border: 1px solid rgba(223, 231, 226, 0.9);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.section h2 {
  margin-top: 0;
  font-size: clamp(1.5rem, 4vw, 2rem);
}

.section h3 {
  margin-top: 28px;
  margin-bottom: 8px;
}

.section p:last-child,
.section ul:last-child,
.section ol:last-child { margin-bottom: 0; }

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

.card {
  padding: 22px;
  border-radius: 18px;
  background: var(--surface-strong);
  border: 1px solid var(--line);
}

.card h3 { margin: 0 0 8px; }
.card p { margin: 0; color: var(--muted); }

.note {
  margin: 20px 0;
  padding: 16px 18px;
  border-left: 5px solid #e5b326;
  border-radius: 12px;
  background: var(--warning);
  color: #5f4a09;
}

.check-list { padding-left: 1.3em; }
.check-list li + li { margin-top: 8px; }

.meta {
  color: var(--muted);
  font-size: 0.92rem;
}

.contact-box {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.site-footer {
  padding: 34px 0 50px;
  color: var(--muted);
  text-align: center;
  font-size: 0.9rem;
}

.fade-in {
  opacity: 0;
  transform: translateY(16px);
  animation: fadeIn 0.7s ease forwards;
}

.fade-in:nth-of-type(2) { animation-delay: 0.08s; }
.fade-in:nth-of-type(3) { animation-delay: 0.16s; }
.fade-in:nth-of-type(4) { animation-delay: 0.24s; }

@keyframes fadeIn {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 720px) {
  .nav {
    align-items: flex-start;
    padding: 14px 0;
  }

  .nav-links {
    gap: 12px;
    font-size: 0.82rem;
  }

  .hero { padding-top: 64px; }
  .grid { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .fade-in {
    opacity: 1;
    transform: none;
    animation: none;
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1511;
    --surface: rgba(22, 34, 28, 0.92);
    --surface-strong: #17231d;
    --text: #f2f7f4;
    --muted: #a8b6ae;
    --line: #2d4036;
    --accent: #34c781;
    --accent-dark: #71e7aa;
    --accent-soft: #173a29;
    --warning: #3d3215;
    --shadow: 0 18px 45px rgba(0, 0, 0, 0.26);
  }

  body {
    background:
      radial-gradient(circle at 12% 0%, rgba(31, 146, 91, 0.22), transparent 34rem),
      linear-gradient(180deg, #101a15 0%, var(--bg) 100%);
  }

  .site-header { background: rgba(13, 21, 17, 0.82); }
  .note { color: #f3df9a; }
}


.code-block {
  overflow-x: auto;
  margin: 18px 0;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--surface-strong);
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 0.92rem;
  line-height: 1.7;
  white-space: pre;
}


.prompt-box {
  position: relative;
  margin: 18px 0 28px;
}

.prompt-box .code-block {
  padding-top: 58px;
  max-height: 520px;
}

.copy-button {
  position: absolute;
  top: 12px;
  right: 12px;
  z-index: 1;
  min-height: 36px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--accent);
  color: #fff;
  font: inherit;
  font-size: 0.84rem;
  font-weight: 800;
  cursor: pointer;
}

.copy-button:hover {
  opacity: 0.84;
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

@media (max-width: 720px) {
  .prompt-box .code-block {
    padding-top: 56px;
    font-size: 0.82rem;
  }

  .copy-button {
    top: 10px;
    right: 10px;
  }
}