/* ========================================
   狐の窓 — 解説サイト
   ======================================== */

:root {
  --color-bg: #f7f5f0;
  --color-surface: #ffffff;
  --color-text: #2d2a26;
  --color-text-muted: #6b665e;
  --color-accent: #8b5c3e;
  --color-accent-light: #c49a6c;
  --color-accent-pale: #f0e6d8;
  --color-border: #e0dbd3;
  --color-code-bg: #f0ece4;
  --color-link: #6b4c30;
  --color-link-hover: #a06830;
  --header-height: 56px;
  --max-width: 760px;
  --font-body: "Hiragino Mincho ProN", "Noto Serif JP", "Yu Mincho", serif;
  --font-code: "IBM Plex Mono", "Source Code Pro", monospace;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 16px);
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.9;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-link);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s, color 0.2s;
}
a:hover {
  color: var(--color-link-hover);
  border-bottom-color: var(--color-accent-light);
}

img { max-width: 100%; height: auto; display: block; }

/* ---- Header ---- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(247, 245, 240, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
}

.site-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-accent);
  letter-spacing: 0.05em;
}
.site-title a {
  color: inherit;
  border: none;
}

/* ---- Nav ---- */
.site-nav ul {
  list-style: none;
  display: flex;
  gap: 4px;
}
.site-nav a {
  display: block;
  padding: 6px 12px;
  font-size: 0.85rem;
  color: var(--color-text-muted);
  border: none;
  border-radius: 4px;
  transition: background 0.2s, color 0.2s;
}
.site-nav a:hover,
.site-nav a.current {
  background: var(--color-accent-pale);
  color: var(--color-accent);
}

/* Hamburger */
.nav-toggle { display: none; }
.hamburger {
  display: none;
  cursor: pointer;
  width: 28px;
  height: 20px;
  position: relative;
  flex-shrink: 0;
}
.hamburger span,
.hamburger::before,
.hamburger::after {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--color-accent);
  transition: transform 0.3s, opacity 0.3s;
}
.hamburger::before { top: 0; }
.hamburger span { top: 9px; }
.hamburger::after { top: 18px; }

.nav-toggle:checked ~ .hamburger::before { transform: translateY(9px) rotate(45deg); }
.nav-toggle:checked ~ .hamburger span { opacity: 0; }
.nav-toggle:checked ~ .hamburger::after { transform: translateY(-9px) rotate(-45deg); }

/* ---- Main ---- */
.site-main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: calc(var(--header-height) + 40px) 24px 80px;
}

/* ---- Hero (top page) ---- */
.hero {
  text-align: center;
  padding: 48px 0 40px;
}
.hero h1 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-accent);
  margin-bottom: 12px;
  letter-spacing: 0.08em;
}
.hero .lead {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  max-width: 520px;
  margin: 0 auto;
}

/* ---- Page title ---- */
.page-title {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--color-accent);
  margin-bottom: 8px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-accent-pale);
}

/* ---- Sections ---- */
h2 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text);
  margin: 48px 0 16px;
  padding-left: 14px;
  border-left: 3px solid var(--color-accent-light);
}

h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin: 32px 0 12px;
  color: var(--color-text);
}

p { margin-bottom: 16px; }

ul, ol {
  margin: 0 0 16px 1.5em;
}
li { margin-bottom: 4px; }

/* ---- Cards (top page navigation) ---- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
  margin: 32px 0;
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 20px 24px;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.card:hover {
  border-color: var(--color-accent-light);
  box-shadow: 0 2px 12px rgba(139, 92, 62, 0.08);
}
.card a {
  border: none;
}
.card .card-num {
  display: inline-block;
  font-size: 0.8rem;
  color: var(--color-accent-light);
  margin-bottom: 4px;
}
.card h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
  color: var(--color-accent);
}
.card p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin: 0;
}

/* ---- Code blocks ---- */
code {
  font-family: var(--font-code);
  font-size: 0.88em;
  background: var(--color-code-bg);
  padding: 2px 6px;
  border-radius: 3px;
}

pre {
  background: var(--color-code-bg);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  padding: 16px 20px;
  overflow-x: auto;
  margin: 0 0 20px;
  line-height: 1.6;
}
pre code {
  background: none;
  padding: 0;
  font-size: 0.85rem;
}

/* ---- Callout / Note ---- */
.note {
  background: var(--color-accent-pale);
  border-left: 3px solid var(--color-accent-light);
  border-radius: 0 6px 6px 0;
  padding: 14px 18px;
  margin: 20px 0;
  font-size: 0.92rem;
}
.note strong {
  color: var(--color-accent);
}

/* ---- Screenshot placeholder ---- */
.screenshot {
  background: var(--color-code-bg);
  border: 2px dashed var(--color-border);
  border-radius: 8px;
  padding: 40px 20px;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.9rem;
  margin: 20px 0;
}

/* ---- Table ---- */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0 24px;
  font-size: 0.92rem;
}
th, td {
  border: 1px solid var(--color-border);
  padding: 8px 12px;
  text-align: left;
}
th {
  background: var(--color-accent-pale);
  font-weight: 600;
  color: var(--color-accent);
}

/* ---- Page nav (prev/next) ---- */
.page-nav {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-top: 64px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
}
.page-nav a {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  border: none;
  transition: color 0.2s;
}
.page-nav a:hover { color: var(--color-accent); }
.page-nav .next { margin-left: auto; }

/* ---- Footer ---- */
.site-footer {
  text-align: center;
  padding: 32px 20px;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  border-top: 1px solid var(--color-border);
}

/* ---- Step list (tutorial) ---- */
.steps {
  counter-reset: step;
  list-style: none;
  margin-left: 0;
  padding: 0;
}
.steps > li {
  counter-increment: step;
  position: relative;
  padding-left: 40px;
  margin-bottom: 24px;
}
.steps > li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 2px;
  width: 28px;
  height: 28px;
  background: var(--color-accent);
  color: #fff;
  font-size: 0.85rem;
  font-weight: 600;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ---- Responsive ---- */
@media (max-width: 640px) {
  .hamburger { display: block; }

  .site-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: rgba(247, 245, 240, 0.97);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--color-border);
    padding: 12px 20px;
    display: none;
  }
  .nav-toggle:checked ~ .site-nav { display: block; }
  .site-nav ul { flex-direction: column; gap: 0; }
  .site-nav a { padding: 10px 12px; font-size: 0.95rem; }

  .hero h1 { font-size: 1.6rem; }
  .page-title { font-size: 1.3rem; }
  h2 { font-size: 1.1rem; }

  .card-grid { grid-template-columns: 1fr; }
}