/* ============================================
   HARUO — Concept Sites
   styles.css
   ============================================ */

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

/* --- Base --- */
body {
  margin: 0;
  font-family: system-ui, -apple-system, 'Helvetica Neue', Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: #1c2333;
  background: #f7f7f6;
  -webkit-font-smoothing: antialiased;
}

main {
  display: block;
}

/* -------------------------------------------
   Page Shell
   header / main / footer を同じ幅で揃える核
------------------------------------------- */
.page-shell {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 20px;
}

/* --- Header --- */
.site-header {
  padding: 24px 0 20px;
  border-bottom: 1px solid #d6d8dc;
}

.site-title {
  text-decoration: none;
  font-weight: 600;
  font-size: 18px;
  color: #1c2333;
  letter-spacing: 0.04em;
}

.site-title:hover {
  opacity: 0.6;
}

/* --- Main --- */
.site-main {
  padding: 0 0 56px;
}

/* --- Typography --- */
h1 {
  font-size: 2.4rem;
  font-weight: 400;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: #2b3a5c;
  margin-bottom: 0.75rem;
}

h2 {
  font-size: 1rem;
  font-weight: 600;
  color: #2b3a5c;
  margin-bottom: 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid #d6d8dc;
}

p {
  margin-bottom: 1rem;
  color: #1c2333;
}

p:last-child {
  margin-bottom: 0;
}

a {
  color: #2b3a5c;
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: opacity 0.15s ease;
}

a:hover {
  opacity: 0.6;
}

ul {
  padding-left: 1.25rem;
  margin-bottom: 1rem;
}

li {
  margin-bottom: 0.35rem;
  color: #1c2333;
}

/* --- Sections --- */
section {
  padding: 3rem 0;
  border-top: 1px solid #d6d8dc;
}

/* Hero はborder-topなし */
.hero {
  padding-top: 3.5rem;
  border-top: none;
}

/* --- Hero parts --- */
.label {
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #5a6272;
  margin-bottom: 1.25rem;
}

.sub {
  font-size: 1.05rem;
  font-style: italic;
  color: #5a6272;
  margin-bottom: 0.75rem;
}

.credit {
  font-size: 0.82rem;
  color: #999;
  margin-bottom: 1.5rem;
}

.intro {
  font-size: 1rem;
  max-width: 600px;
}

/* --- Closing (concept restatement) --- */
.closing {
  padding: 3rem 0 2rem;
  border-top: 1px solid #d6d8dc;
  text-align: center;
}

.closing-title {
  font-size: 1rem;
  font-weight: 600;
  color: #2b3a5c;
  margin-bottom: 0.5rem;
}

.closing-sub {
  font-style: italic;
  color: #5a6272;
  font-size: 0.92rem;
  margin-bottom: 0.625rem;
}

.closing-credit {
  font-size: 0.75rem;
  color: #aaa;
}

/* -------------------------------------------
   Footer
   page-shell 内なので左右は自動で揃う。
   縦余白のみここで管理。
------------------------------------------- */
.site-footer {
  padding: 40px 0 32px;
  border-top: 1px solid #d6d8dc;
}

.footer-inner {
  display: flex;
  align-items: flex-start;
  justify-content: flex-start;
  gap: 64px;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.footer-cta a {
  font-size: 0.875rem;
  color: #5a6272;
  text-decoration: none;
  transition: color 0.18s;
}

.footer-cta a:hover {
  color: #2b3a5c;
  opacity: 1;
}

.footer-concepts__heading {
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: #999;
  margin-bottom: 0.625rem;
}

.footer-concepts ul {
  list-style: none;
  padding-left: 0;
  margin-bottom: 0;
}

.footer-concepts li {
  margin-bottom: 0.5rem;
  line-height: 1.5;
}

.footer-concepts li:last-child {
  margin-bottom: 0;
}

.footer-concepts a {
  font-size: 0.8125rem;
  color: #999;
  text-decoration: none;
  transition: color 0.18s;
}

.footer-concepts a:hover {
  color: #2b3a5c;
  opacity: 1;
}

.footer-concepts .current {
  font-size: 0.8125rem;
  color: #ccc;
  cursor: default;
}

/* --- Concept Nav --- */
.concept-nav {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 0 0;
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  flex-wrap: wrap;
  color: #999;
}
.concept-nav__sep { color: #d6d8dc; }
.concept-nav__links { display: flex; gap: 12px; flex-wrap: wrap; }
.concept-nav__link {
  color: #999;
  text-decoration: none;
  transition: color 0.18s;
}
.concept-nav__link:hover { color: #2b3a5c; opacity: 1; }
.concept-nav__link.current { color: #5a6272; }

/* footer description sub-text */
.footer-field-desc { color: #bbb; font-size: 0.75rem; }

/* External link indicator */
a.external::after {
  content: "↗";
  font-size: 0.7em;
  margin-left: 3px;
  color: #999;
  opacity: 0.7;
  transition: opacity 0.18s, color 0.18s;
}

a.external:hover::after {
  opacity: 1;
  color: #2b3a5c;
}

.footer-shortdef {
  font-size: 0.78rem;
  color: #bbb;
  font-style: italic;
  line-height: 1.8;
  margin-bottom: 1rem;
}

.footer-copy {
  font-size: 0.72rem;
  color: #aaa;
  letter-spacing: 0.02em;
}

/* --- Field Nav (position indicator) --- */
.field-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2.5rem 0 1.25rem;
}

.field-nav__node {
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: #1c2333;
  text-decoration: none;
  opacity: 0.28;
  padding: 0.25rem 1.5rem;
  position: relative;
  transition: opacity 0.2s;
}

.field-nav__node + .field-nav__node::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  width: 1px;
  height: 12px;
  background: #d6d8dc;
  transform: translateY(-50%);
}

.field-nav__node:hover {
  opacity: 0.75;
}

.field-nav__node.current {
  opacity: 1;
  color: #2b3a5c;
  cursor: default;
}

/* --- Field Pair (experiential placement) --- */
.field-pair {
  padding: 2rem 0 0.5rem;
  display: flex;
  align-items: baseline;
  gap: 5rem;
}

.field-pair span {
  font-size: 0.875rem;
  letter-spacing: 0.06em;
  color: #aaa;
  font-style: italic;
}

/* --- Responsive --- */
@media (max-width: 600px) {
  h1 {
    font-size: 1.9rem;
  }

  .hero {
    padding-top: 2.5rem;
  }

  section {
    padding: 2.25rem 0;
  }

  .footer-inner {
    flex-direction: column;
    gap: 24px;
  }

  .site-footer {
    padding: 32px 0 24px;
  }
}