:root {
  --bg: #f4f6f9;
  --bg-elevated: #ffffff;
  --border: rgba(15, 23, 42, 0.1);
  --text: #0f172a;
  --muted: #64748b;
  --accent: #2563eb;
  --accent-soft: rgba(37, 99, 235, 0.15);
  --radius: 14px;
  --shadow: 0 10px 40px rgba(15, 23, 42, 0.08);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  font-family: "Noto Sans JP", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(ellipse 80% 50% at 50% -15%, rgba(37, 99, 235, 0.12), transparent 55%),
    radial-gradient(ellipse 55% 35% at 100% 0%, rgba(139, 92, 246, 0.06), transparent 50%);
  z-index: 0;
}

.wrap {
  position: relative;
  z-index: 1;
  max-width: 720px;
  margin: 0 auto;
  padding: clamp(2rem, 5vw, 3.5rem) clamp(1.25rem, 4vw, 2rem) 4rem;
}

header {
  margin-bottom: 2.5rem;
}

.brand {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 700;
  letter-spacing: 0.04em;
  margin: 0 0 0.35rem;
}

.tagline {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
  font-weight: 400;
}

section {
  margin-bottom: 2.25rem;
}

h2 {
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--muted);
  margin: 0 0 0.85rem;
}

ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

a.card {
  display: block;
  text-decoration: none;
  color: inherit;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.15rem;
  transition: border-color 0.2s, background 0.2s, transform 0.2s, box-shadow 0.2s;
  box-shadow: var(--shadow);
}

a.card:hover,
a.card:focus-visible {
  border-color: rgba(37, 99, 235, 0.28);
  background: #fafbff;
  transform: translateY(-1px);
  outline: none;
}

a.card:focus-visible {
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.card-title {
  font-weight: 600;
  font-size: 1.02rem;
  margin: 0 0 0.2rem;
}

.card-meta {
  font-size: 0.82rem;
  color: var(--muted);
  margin: 0;
}

.external .card-meta {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.external .card-meta::after {
  content: "↗";
  font-size: 0.75rem;
  opacity: 0.65;
}