:root {
  color-scheme: light;
  --ink: #17202a;
  --muted: #5c6873;
  --line: #dfe5ea;
  --paper: #ffffff;
  --wash: #f4f7f9;
  --accent: #176b87;
  --accent-soft: #e5f4f7;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 10% 0%, #e8f6f8 0, transparent 34rem),
    var(--wash);
  font: 16px/1.75 -apple-system, BlinkMacSystemFont, "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

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

.shell {
  width: min(860px, calc(100% - 32px));
  margin: 0 auto;
}

header { padding: 56px 0 28px; }

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  text-decoration: none;
  font-weight: 750;
}

.mark {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: 13px;
  color: white;
  background: linear-gradient(145deg, #1e879f, #124f70);
  box-shadow: 0 10px 24px #176b8730;
}

nav { float: right; padding-top: 8px; }
nav a { margin-left: 20px; color: var(--muted); text-decoration: none; }

main {
  overflow: hidden;
  margin-bottom: 36px;
  padding: clamp(28px, 6vw, 58px);
  border: 1px solid var(--line);
  border-radius: 28px;
  background: color-mix(in srgb, var(--paper) 94%, transparent);
  box-shadow: 0 24px 70px #17384a12;
}

h1, h2 { line-height: 1.28; letter-spacing: -0.02em; }
h1 { margin: 0 0 16px; font-size: clamp(34px, 6vw, 56px); }
h2 { margin: 2em 0 0.55em; font-size: 23px; }
p, li { color: #303c46; }
.lead { max-width: 42rem; color: var(--muted); font-size: 18px; }
.meta { color: var(--muted); font-size: 14px; }

.cards {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 34px;
}

.card {
  display: block;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 18px;
  color: var(--ink);
  background: var(--paper);
  text-decoration: none;
}
.card:hover { border-color: #8fc6d2; transform: translateY(-1px); }
.card strong { display: block; margin-bottom: 5px; }
.card span { color: var(--muted); }

.notice {
  margin: 24px 0;
  padding: 18px 20px;
  border-left: 4px solid var(--accent);
  border-radius: 10px;
  background: var(--accent-soft);
}

footer {
  padding: 0 0 42px;
  color: var(--muted);
  text-align: center;
  font-size: 14px;
}

@media (max-width: 620px) {
  header { padding-top: 28px; }
  nav { float: none; margin-top: 18px; }
  nav a { margin: 0 18px 0 0; }
  .cards { grid-template-columns: 1fr; }
}