:root {
  --bg: #F2F7EE;
  --card: #ffffff;
  --fg: #2E3B2A;
  --muted: #5B6B52;
  --line: #DCE7DA;
  --accent: #6BBF59;
  --sky: #8FD3EE;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP",
    "Yu Gothic", Meiryo, sans-serif;
  line-height: 1.8;
  font-size: 16px;
}

header {
  background: linear-gradient(180deg, var(--sky) 0%, var(--bg) 100%);
  padding: 40px 20px 28px;
  text-align: center;
}

header .frog { font-size: 44px; line-height: 1; }

header h1 {
  margin: 10px 0 4px;
  font-size: 24px;
  letter-spacing: .02em;
}

header p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

nav {
  display: flex;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
  padding: 16px 20px 0;
}

nav a {
  display: inline-block;
  padding: 7px 16px;
  border-radius: 999px;
  background: var(--card);
  border: 1px solid var(--line);
  color: var(--fg);
  text-decoration: none;
  font-size: 13.5px;
}

nav a:hover { border-color: var(--accent); }

main {
  max-width: 760px;
  margin: 0 auto;
  padding: 24px 20px 64px;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 24px 24px 28px;
  margin-bottom: 20px;
}

h2 {
  font-size: 19px;
  margin: 0 0 14px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--accent);
  display: inline-block;
}

h3 {
  font-size: 15.5px;
  margin: 22px 0 8px;
  color: var(--fg);
}

p, li { color: var(--fg); }

ul { padding-left: 1.3em; }

li { margin-bottom: 6px; }

.muted { color: var(--muted); font-size: 13.5px; }

.notice {
  background: #FBF3DC;
  border: 1px solid #EBD9A6;
  border-radius: 12px;
  padding: 14px 16px;
  font-size: 14px;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14.5px;
  margin: 10px 0;
}

th, td {
  border: 1px solid var(--line);
  padding: 9px 11px;
  text-align: left;
  vertical-align: top;
}

th { background: #EAF6E4; width: 32%; }

a { color: #2f7fb5; }

footer {
  text-align: center;
  padding: 28px 20px 44px;
  color: var(--muted);
  font-size: 13px;
}

.updated { color: var(--muted); font-size: 13px; margin-top: 0; }

@media (max-width: 480px) {
  .card { padding: 20px 16px 22px; }
  th, td { display: block; width: 100%; border-top: none; }
  th { border-top: 1px solid var(--line); }
}