/* ── Reset & Base ─────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:        #0e1117;
  --bg-card:   #161b25;
  --border:    #2a3040;
  --text:      #c8d0dc;
  --text-dim:  #6b7a90;
  --accent:    #4af0b0;   /* ターミナルグリーン — BBSへのオマージュ */
  --accent2:   #1a8a6a;
  --nav-h:     56px;
  --font-mono: 'Courier New', Courier, monospace;
  --font-sans: 'Helvetica Neue', Arial, sans-serif;
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  min-height: 100vh;
}

/* ── Nav ───────────────────────────────────────── */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-h);
  background: rgba(14,17,23,0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 24px;
  gap: 32px;
}

.nav-logo {
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--accent);
  text-decoration: none;
  letter-spacing: 0.05em;
  white-space: nowrap;
}

.nav-links {
  display: flex;
  gap: 24px;
  list-style: none;
  margin-left: auto;
}

.nav-links a {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-dim);
  text-decoration: none;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  transition: color 0.2s;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] { color: var(--accent); }

/* ハンバーガー（モバイル用） */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  margin-left: auto;
  background: none;
  border: none;
  padding: 4px;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-dim);
  transition: background 0.2s;
}
.nav-toggle:hover span { background: var(--accent); }

/* ── Hero ──────────────────────────────────────── */
.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: 48px;
  max-width: 1000px;
  margin: 0 auto;
  padding: 80px 24px 64px;
}

.hero-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.hero-title {
  font-family: var(--font-mono);
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 700;
  color: #fff;
  line-height: 1.1;
  margin-bottom: 20px;
}

.hero-title .cursor {
  display: inline-block;
  width: 3px;
  height: 1em;
  background: var(--accent);
  vertical-align: middle;
  margin-left: 4px;
  animation: blink 1s step-end infinite;
}

@keyframes blink { 50% { opacity: 0; } }

.hero-desc {
  color: var(--text-dim);
  font-size: 0.95rem;
  max-width: 420px;
}

/* 挿絵エリア */
.hero-image {
  aspect-ratio: 1 / 1;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg-card);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  color: var(--text-dim);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  overflow: hidden;
  position: relative;
}

.hero-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  position: absolute;
  inset: 0;
}

.hero-image-placeholder {
  text-align: center;
  line-height: 2;
  z-index: 1;
}

.placeholder-icon {
  font-size: 2.5rem;
  display: block;
  margin-bottom: 8px;
  opacity: 0.4;
}

/* ── モバイル：ヒーロー背景画像 ────────────────── */
@media (max-width: 680px) {
  .hero {
    position: relative;
    isolation: isolate;
  }
  .hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image: var(--hero-bg, none);
    background-size: cover;
    background-position: center top;
    opacity: 0.18;
    z-index: -1;
    border-radius: 0;
    pointer-events: none;
  }
}

/* ── Sections grid ─────────────────────────────── */
.sections {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 24px 80px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 24px;
  text-decoration: none;
  color: inherit;
  display: block;
  transition: border-color 0.2s, transform 0.2s;
}

.card:hover {
  border-color: var(--accent2);
  transform: translateY(-2px);
}

.card-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: 8px;
}

.card-title {
  font-size: 1rem;
  font-weight: 600;
  color: #fff;
  margin-bottom: 6px;
}

.card-desc {
  font-size: 0.85rem;
  color: var(--text-dim);
  line-height: 1.6;
}

.card-status {
  display: inline-block;
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-dim);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 2px 8px;
}

/* ── Footer ────────────────────────────────────── */
footer {
  border-top: 1px solid var(--border);
  padding: 24px;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-dim);
}

/* ── Responsive ────────────────────────────────── */
@media (max-width: 680px) {
  .hero {
    grid-template-columns: 1fr;
    padding: 48px 20px 40px;
    gap: 32px;
  }

  .hero-image { order: -1; max-width: 280px; margin: 0 auto; }

  .nav-links { display: none; }
  .nav-toggle { display: flex; }

  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: fixed;
    top: var(--nav-h);
    left: 0; right: 0;
    background: rgba(14,17,23,0.97);
    border-bottom: 1px solid var(--border);
    padding: 20px 24px;
    gap: 16px;
  }
}