:root {
  --felt: #097a50;
  --felt-tint: #e1f1e8;
  --sun-tint: #fff2cc;
  --bg: #f2f5f3;
  --card: #ffffff;
  --line: #dfe6e2;
  --ink: #15201b;
  --ink2: #5c6a64;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --felt: #34b985;
    --felt-tint: #12301f;
    --sun-tint: #3a3213;
    --bg: #0a0f0d;
    --card: #151d1a;
    --line: #26312c;
    --ink: #e5ede9;
    --ink2: #9baaa3;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic", sans-serif;
  font-size: 16px;
  line-height: 1.8;
  -webkit-text-size-adjust: 100%;
}

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

.wrap { max-width: 720px; margin: 0 auto; padding: 0 16px; }

header { border-bottom: 1px solid var(--line); background: var(--card); }
header .wrap { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 60px; flex-wrap: wrap; }
.logo { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font-weight: 800; }
.logo img { width: 32px; height: 32px; border-radius: 8px; }
nav { display: flex; gap: 16px; font-size: 14px; font-weight: 700; }
nav a { text-decoration: none; }
nav a[aria-current="page"] { color: var(--ink); }

main { padding: 28px 0 48px; }

h1 { font-size: 28px; line-height: 1.35; margin: 0 0 8px; font-weight: 800; }
h2 { font-size: 20px; line-height: 1.4; margin: 36px 0 10px; font-weight: 800; }
h3 { font-size: 16px; margin: 20px 0 6px; font-weight: 800; }
p { margin: 0 0 12px; }
ul, ol { margin: 0 0 12px; padding-left: 1.4em; }
li { margin-bottom: 4px; }

.lead { font-size: 17px; color: var(--ink2); }
.meta { font-size: 14px; color: var(--ink2); }

.hero { display: flex; align-items: center; gap: 18px; margin-bottom: 20px; }
.hero img { width: 88px; height: 88px; border-radius: 20px; flex: none; }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 16px 18px;
  margin: 12px 0;
}
.card.tip { background: var(--sun-tint); border-color: var(--sun-tint); }
.card h3 { margin-top: 0; }

.features { list-style: none; padding: 0; display: grid; gap: 10px; }
.features li { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 12px 16px; margin: 0; }
.features strong { display: block; }

.button {
  display: inline-block;
  background: var(--felt);
  color: #fff;
  font-weight: 800;
  text-decoration: none;
  border-radius: 14px;
  padding: 12px 20px;
}
@media (prefers-color-scheme: dark) { .button { color: #04140d; } }

footer { border-top: 1px solid var(--line); padding: 20px 0 32px; font-size: 14px; color: var(--ink2); }