/* データマネジメントアカデミー サイト共通 */

:root {
  --color-bg: #0f1419;
  --color-surface: #1a222d;
  --color-surface-2: #232d3b;
  --color-text: #e8edf2;
  --color-muted: #9aa5b1;
  --color-accent: #3db8a8;
  --color-accent-dim: #2a8f82;
  --color-border: #2f3d4d;
  --font-sans: "Segoe UI", "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", Meiryo, sans-serif;
  --radius: 10px;
  --shadow: 0 12px 40px rgba(0, 0, 0, 0.35);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--color-text);
  background: var(--color-bg);
  background-image:
    radial-gradient(ellipse 120% 80% at 50% -20%, rgba(61, 184, 168, 0.12), transparent),
    radial-gradient(ellipse 80% 50% at 100% 50%, rgba(61, 184, 168, 0.06), transparent);
  min-height: 100vh;
}

a {
  color: var(--color-accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.2em;
}

a:hover {
  color: #5fd4c4;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(15, 20, 25, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
}

.site-header__inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 0.85rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.site-logo {
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: 0.02em;
  color: var(--color-text);
  text-decoration: none;
}

.site-logo:hover {
  color: var(--color-accent);
}

.site-nav {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.site-nav a {
  font-size: 0.9rem;
  color: var(--color-muted);
  text-decoration: none;
}

.site-nav a:hover {
  color: var(--color-accent);
}

main {
  max-width: 960px;
  margin: 0 auto;
  padding: 2rem 1.25rem 4rem;
}

.hero {
  text-align: center;
  padding: 2.5rem 0 3rem;
}

.hero__label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 0.75rem;
}

.hero h1 {
  margin: 0 0 1rem;
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: 0.02em;
}

.hero__lead {
  margin: 0 auto;
  max-width: 36em;
  color: var(--color-muted);
  font-size: 1.05rem;
}

.cards {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  margin-top: 1rem;
}

.card {
  display: flex;
  flex-direction: column;
  padding: 1.5rem 1.35rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: border-color 0.2s, transform 0.2s;
}

.card:hover {
  border-color: var(--color-accent-dim);
  transform: translateY(-2px);
}

.card h2 {
  margin: 0 0 0.5rem;
  font-size: 1.15rem;
  font-weight: 700;
}

.card p {
  margin: 0 0 1.25rem;
  flex: 1;
  color: var(--color-muted);
  font-size: 0.95rem;
}

.card__link {
  align-self: flex-start;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
}

.card__link::after {
  content: " →";
}

.doc-page h1 {
  margin: 0 0 0.35rem;
  font-size: 1.65rem;
  font-weight: 700;
}

.doc-page .doc-subtitle {
  margin: 0 0 2rem;
  font-size: 1.1rem;
  font-weight: 400;
  color: var(--color-muted);
}

.doc-section {
  margin-bottom: 2rem;
  padding: 1.35rem 1.25rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.doc-section h2 {
  margin: 0 0 1rem;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-accent);
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 0.5rem;
}

.doc-section h3 {
  margin: 1.25rem 0 0.5rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text);
}

.doc-section p {
  margin: 0 0 1rem;
  color: var(--color-text);
}

.doc-section p:last-child {
  margin-bottom: 0;
}

.doc-section ul {
  margin: 0 0 1rem;
  padding-left: 1.25rem;
  color: var(--color-text);
}

.doc-section li {
  margin-bottom: 0.35rem;
}

.doc-section li:last-child {
  margin-bottom: 0;
}

.doc-note {
  margin-top: 1rem;
  padding: 0.85rem 1rem;
  background: var(--color-surface-2);
  border-radius: 6px;
  font-size: 0.9rem;
  color: var(--color-muted);
  border-left: 3px solid var(--color-accent-dim);
}

.doc-back {
  display: inline-block;
  margin-bottom: 1.5rem;
  font-size: 0.9rem;
  color: var(--color-muted);
  text-decoration: none;
}

.doc-back:hover {
  color: var(--color-accent);
}

.site-footer {
  max-width: 960px;
  margin: 0 auto;
  padding: 2rem 1.25rem;
  border-top: 1px solid var(--color-border);
  font-size: 0.85rem;
  color: var(--color-muted);
  text-align: center;
}