:root {
  --bg: #f9fbfc;
  --card: #ffffff;
  --text: #1f2933;
  --muted: #5d6b78;
  --accent: #174a5b;
  --line: #d9e1e7;
  --shadow: 0 8px 20px rgba(16, 35, 52, 0.06);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Hiragino Kaku Gothic ProN", "Yu Gothic", "Meiryo", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.8;
}

.container {
  width: min(1000px, 92%);
  margin: 0 auto;
}

.site-header,
.site-footer {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: #fff;
}

.site-title {
  margin: 0;
  padding: 1rem 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.hero {
  padding: 3.5rem 0 2rem;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 2rem;
  align-items: center;
}

.eyebrow {
  color: var(--accent);
  font-weight: 700;
  margin-bottom: 0.5rem;
}

h1, h2 { line-height: 1.4; }
h1 { margin: 0 0 1rem; font-size: clamp(1.6rem, 3vw, 2.2rem); }
h2 { margin-top: 0; font-size: 1.4rem; color: #183342; }

.lead { color: #324a5a; }

.cover-card,
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: var(--shadow);
}

.cover-card { padding: 1rem; }
.cover-card img { width: 100%; display: block; border-radius: 8px; }

.section { padding: 1rem 0; }
.card { padding: 1.5rem; }

ul { margin: 0; padding-left: 1.2rem; }

.btn {
  display: inline-block;
  border: 1px solid var(--accent);
  color: var(--accent);
  background: #fff;
  border-radius: 999px;
  padding: 0.5rem 1rem;
  text-decoration: none;
  font-size: 0.95rem;
  cursor: pointer;
  transition: 0.2s ease;
}

.btn:hover { transform: translateY(-1px); opacity: 0.9; }

.btn.primary {
  background: var(--accent);
  color: #fff;
}

.button-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1.2rem;
}

textarea {
  width: 100%;
  min-height: 180px;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1rem;
  font-size: 0.95rem;
  line-height: 1.7;
  background: #fcfefe;
}

#copyStatus { color: var(--muted); margin-top: 0.6rem; min-height: 1.5em; }

.site-footer { margin-top: 2rem; }
.site-footer small { display: inline-block; padding: 1rem 0; color: var(--muted); }

@media (max-width: 820px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero { padding-top: 2rem; }
}