:root {
  --sea: #0e6b62;
  --sea-soft: #2a8a7e;
  --foam: #fffcf6;
  --mist: #e4eee8;
  --ink: #24332f;
  --ink-muted: #5e746e;
  --max-width: 720px;
}

* {
  box-sizing: border-box;
}

body {
  font-family: "Hiragino Sans", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
  line-height: 1.7;
  margin: 0;
  color: var(--ink);
  background: linear-gradient(180deg, #c5ddd8 0%, var(--mist) 40%, #eef4f1 100%);
  min-height: 100vh;
}

a {
  color: var(--sea);
}

a:hover {
  color: var(--sea-soft);
}

.site-header {
  background: var(--sea);
  color: #fff;
  padding: 14px 20px;
}

.site-header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.site-logo {
  font-weight: 800;
  font-size: 1.05rem;
  color: #fff;
  text-decoration: none;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  font-size: 0.9rem;
}

.site-nav a {
  color: rgba(255, 255, 255, 0.92);
  text-decoration: none;
}

.site-nav a:hover {
  color: #fff;
  text-decoration: underline;
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 28px 16px 56px;
}

.card {
  background: var(--foam);
  border-radius: 12px;
  padding: 24px 20px;
  box-shadow: 0 2px 12px rgba(14, 107, 98, 0.08);
  margin-bottom: 20px;
}

.hero {
  text-align: center;
  padding: 36px 20px;
}

.hero h1 {
  font-size: 1.75rem;
  margin: 0 0 8px;
  color: var(--sea);
}

.hero p {
  color: var(--ink-muted);
  margin: 0;
}

h1.page-title {
  font-size: 1.5rem;
  margin: 0 0 0.75em;
  color: var(--sea);
}

h2 {
  font-size: 1.15rem;
  margin: 1.75em 0 0.5em;
  color: var(--ink);
}

h3 {
  font-size: 1rem;
  margin: 1.25em 0 0.4em;
}

ul,
ol {
  padding-left: 1.4em;
}

.meta {
  color: var(--ink-muted);
  font-size: 0.95rem;
}

.link-grid {
  display: grid;
  gap: 12px;
  margin-top: 8px;
}

.link-card {
  display: block;
  padding: 16px 18px;
  background: #fff;
  border: 1px solid #d5e0da;
  border-radius: 10px;
  text-decoration: none;
  color: var(--ink);
}

.link-card:hover {
  border-color: var(--sea-soft);
  box-shadow: 0 4px 14px rgba(14, 107, 98, 0.12);
}

.link-card strong {
  display: block;
  color: var(--sea);
  margin-bottom: 4px;
}

.link-card span {
  font-size: 0.9rem;
  color: var(--ink-muted);
}

.btn {
  display: inline-block;
  padding: 12px 20px;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 700;
  text-decoration: none;
  background: var(--sea);
  color: #fff;
}

.btn:hover {
  background: var(--sea-soft);
  color: #fff;
}

.site-footer {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 24px 16px 40px;
  text-align: center;
  font-size: 0.85rem;
  color: var(--ink-muted);
}