:root {
  color-scheme: light;
  --bg: #f6f7fb;
  --surface: #ffffff;
  --text: #172033;
  --muted: #667085;
  --border: #e5e7eb;
  --primary: #4252d9;
  --primary-soft: #eef1ff;
  --warning: #fff7ed;
  --warning-border: #fed7aa;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
}

.wrap {
  width: min(920px, calc(100% - 32px));
  margin: 0 auto;
}

header {
  background: linear-gradient(135deg, #ffffff 0%, #eef1ff 100%);
  border-bottom: 1px solid var(--border);
}

header .wrap { padding: 40px 0 28px; }

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--primary);
  font-weight: 900;
  letter-spacing: -0.02em;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 12px;
  background: var(--primary);
  color: #fff;
}

h1 { margin: 16px 0 4px; font-size: clamp(2rem, 7vw, 3.2rem); line-height: 1.1; letter-spacing: -0.04em; }
h2 { margin: 0 0 10px; line-height: 1.25; }
h3 { margin: 26px 0 6px; line-height: 1.3; }
p { margin: 8px 0 14px; }
ul, ol { padding-left: 24px; }
li + li { margin-top: 7px; }

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  margin-top: 20px;
}

nav a, a { color: var(--primary); }
nav a { font-weight: 700; text-decoration: none; }

main { padding: 12px 0 24px; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: clamp(20px, 5vw, 30px);
  margin: 20px 0;
  box-shadow: 0 8px 30px rgba(23, 32, 51, 0.04);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 14px;
}

.grid .card { margin: 0; }
.meta { color: var(--muted); font-size: 0.94rem; }
.small { color: var(--muted); font-size: 0.9rem; }

.button {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  text-decoration: none;
  font-weight: 800;
  padding: 11px 16px;
  border-radius: 12px;
}

.notice {
  background: var(--warning);
  border: 1px solid var(--warning-border);
  border-radius: 12px;
  padding: 14px 16px;
}

.info {
  background: var(--primary-soft);
  border: 1px solid #dce1ff;
  border-radius: 12px;
  padding: 14px 16px;
}

footer { color: var(--muted); padding: 8px 0 40px; font-size: 0.92rem; }
code { background: #f0f2f6; border-radius: 6px; padding: 2px 6px; }

@media (max-width: 520px) {
  header .wrap { padding-top: 28px; }
  .card { border-radius: 14px; }
}