:root {
  --bg: #eef2f7;
  --paper: #ffffff;
  --ink: #1b2430;
  --ink-soft: #5a6675;
  --accent: #1565c0;
  --accent-2: #007aff;
  --accent-soft: #e4eefb;
  --rule: #dbe3ec;
  --warn-bg: #fff4e0;
  --warn-ink: #7a4b00;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e1620;
    --paper: #1a2431;
    --ink: #e8eef6;
    --ink-soft: #a5b3c4;
    --accent: #8ab8ee;
    --accent-2: #6db2ff;
    --accent-soft: #22344a;
    --rule: #2c3d52;
    --warn-bg: #3d2f14;
    --warn-ink: #ffd89a;
  }
}

* { box-sizing: border-box; }
html, body {
  margin: 0; padding: 0;
  background: var(--bg); color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", "Meiryo", sans-serif;
  line-height: 1.85; font-size: 16px;
  -webkit-text-size-adjust: 100%;
}
a { color: var(--accent); }

.wrap { max-width: 760px; margin: 0 auto; padding: 40px 20px 80px; }
.paper {
  background: var(--paper); border-radius: 18px; padding: 44px 40px;
  box-shadow: 0 8px 24px rgba(15, 30, 50, .10), 0 2px 6px rgba(15, 30, 50, .06);
}

.hero { display: flex; align-items: center; gap: 14px; margin-bottom: 4px; }
.hero-mark {
  width: 46px; height: 46px; border-radius: 12px; flex: none;
  display: grid; place-items: center; font-size: 22px; font-weight: 700; color: #fff;
  background: linear-gradient(135deg, #1565c0, #0a3e82);
  box-shadow: 0 4px 12px rgba(21, 101, 192, .38);
}
.app-name { font-size: 13px; color: var(--ink-soft); letter-spacing: .06em; }

h1 { font-size: 26px; margin: 2px 0 0; line-height: 1.4; }
h2 { font-size: 19px; margin: 36px 0 10px; padding-bottom: 6px; border-bottom: 2px solid var(--accent-soft); }
h3 { font-size: 16px; margin: 22px 0 6px; color: var(--accent); }

.updated { color: var(--ink-soft); font-size: 13px; margin: 14px 0 0; }
.lead { color: var(--ink-soft); margin-top: 18px; }
.back { display: inline-block; font-size: 14px; margin-bottom: 18px; text-decoration: none; }
.back:hover { text-decoration: underline; }

table { width: 100%; border-collapse: collapse; margin: 14px 0; font-size: 15px; }
th, td { border: 1px solid var(--rule); padding: 10px 12px; text-align: left; vertical-align: top; }
th { background: var(--accent-soft); font-weight: 700; white-space: nowrap; }

ul, ol { padding-left: 1.3em; }
li { margin: 4px 0; }

.note {
  background: var(--warn-bg); color: var(--warn-ink);
  border-radius: 12px; padding: 14px 18px; margin: 18px 0; font-size: 15px;
}
.note strong { color: inherit; }

.mail { font-size: 19px; font-weight: 700; margin: 8px 0; word-break: break-all; }

.cards { display: grid; gap: 12px; margin: 26px 0 6px; }
.card {
  position: relative; display: block; text-decoration: none; color: inherit;
  border: 1px solid var(--rule); border-radius: 14px; padding: 18px 46px 18px 20px;
  background: var(--paper); transition: border-color .15s, transform .15s;
}
.card:hover { border-color: var(--accent); transform: translateY(-1px); }
.card .t { font-weight: 700; font-size: 17px; }
.card .d { color: var(--ink-soft); font-size: 14px; line-height: 1.6; }
.card .arrow { position: absolute; right: 20px; top: 50%; transform: translateY(-50%); color: var(--accent); font-size: 18px; }

footer { text-align: center; color: var(--ink-soft); font-size: 13px; margin-top: 26px; }

.en { margin-top: 44px; padding-top: 26px; border-top: 1px dashed var(--rule); }
.en h2 { font-size: 17px; }

@media (max-width: 560px) {
  .paper { padding: 28px 20px; border-radius: 14px; }
  h1 { font-size: 22px; }
}