/* ============================================================
   H₂ LIFE — Design System
   白・淡青・透明感・余白・清潔感・静かな知性
   ============================================================ */

/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Cormorant+Garamond:ital,wght@0,300;0,400;1,300&family=Noto+Sans+JP:wght@300;400;500&family=Noto+Serif+JP:wght@300;400&display=swap');

/* ── CSS Variables ── */
:root {
  --white:       #ffffff;
  --off-white:   #f8f9fb;
  --cream:       #f4f6f9;
  --blue-pale:   #eaf2f8;
  --blue-light:  #c8dff0;
  --blue:        #4a90b8;
  --blue-mid:    #2e6f96;
  --blue-deep:   #1a4a6e;
  --navy:        #0d2d45;
  --text:        #1c2b38;
  --text-mid:    #3d5263;
  --muted:       #7a8f9e;
  --border:      #dde6ed;
  --border-light:#eef3f7;

  --font-serif:  'Noto Serif JP', 'Cormorant Garamond', serif;
  --font-sans:   'Noto Sans JP', sans-serif;
  --font-display:'Cormorant Garamond', serif;

  --max:         1080px;
  --max-narrow:  720px;
  --pad-x:       clamp(1.2rem, 5vw, 4rem);
  --pad-y:       clamp(4rem, 8vw, 7rem);
  --radius:      2px;

  --shadow-sm:   0 1px 4px rgba(13,45,69,.06);
  --shadow-md:   0 4px 20px rgba(13,45,69,.08);
  --shadow-lg:   0 12px 40px rgba(13,45,69,.12);

  --transition:  .3s cubic-bezier(.4,0,.2,1);
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-sans);
  font-size: clamp(15px, 2vw, 17px);
  line-height: 1.9;
  color: var(--text);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { cursor: pointer; font-family: inherit; border: none; background: none; }

/* ── Typography ── */
h1, h2, h3, h4, h5 {
  font-family: var(--font-serif);
  font-weight: 300;
  line-height: 1.45;
  color: var(--navy);
}
h1 { font-size: clamp(1.8rem, 4vw, 2.8rem); }
h2 { font-size: clamp(1.4rem, 3vw, 2rem); }
h3 { font-size: clamp(1.1rem, 2vw, 1.4rem); }
h4 { font-size: clamp(1rem, 1.6vw, 1.15rem); }

.display {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 300;
}
.label {
  font-size: clamp(.65rem, .9vw, .72rem);
  letter-spacing: .28em;
  text-transform: uppercase;
  color: var(--blue);
  font-weight: 400;
}
.body-text {
  font-size: clamp(.95rem, 1.3vw, 1.02rem);
  line-height: 2;
  color: var(--text-mid);
  font-weight: 300;
}

/* ── Layout ── */
.container {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--pad-x);
}
.container--narrow {
  max-width: var(--max-narrow);
  margin: 0 auto;
  padding: 0 var(--pad-x);
}
.section {
  padding: var(--pad-y) var(--pad-x);
}

/* ── Header / Nav ── */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
  transition: box-shadow var(--transition);
}
.site-header.scrolled {
  box-shadow: var(--shadow-sm);
}
.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 clamp(.8rem, 2.5vw, 2rem);
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.site-logo {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 300;
  letter-spacing: .1em;
  color: var(--navy);
  display: flex;
  align-items: baseline;
  gap: .2rem;
  flex-shrink: 0;
}
.site-logo sub {
  font-size: .6em;
  color: var(--blue);
}

/* PC Nav */
.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(.4rem, 1.2vw, 1.2rem);
  flex-wrap: nowrap;
}
.nav-list a {
  font-size: clamp(.68rem, .85vw, .78rem);
  letter-spacing: .04em;
  white-space: nowrap;
  color: var(--text-mid);
  transition: color var(--transition);
  position: relative;
}
.nav-list a::after {
  content: '';
  position: absolute;
  bottom: -2px; left: 0;
  width: 0; height: 1px;
  background: var(--blue);
  transition: width var(--transition);
}
.nav-list a:hover { color: var(--blue); }
.nav-list a:hover::after { width: 100%; }
.nav-list a.active { color: var(--blue); }
.nav-list a.active::after { width: 100%; }

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  z-index: 101;
}
.hamburger span {
  display: block;
  width: 22px; height: 1.5px;
  background: var(--navy);
  transition: var(--transition);
}
.hamburger.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* Mobile Nav */
.mobile-nav {
  display: none;
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(255,255,255,.97);
  backdrop-filter: blur(20px);
  z-index: 99;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition);
}
.mobile-nav.open {
  opacity: 1;
  pointer-events: all;
}
.mobile-nav a {
  font-family: var(--font-serif);
  font-size: clamp(1.2rem, 4vw, 1.5rem);
  font-weight: 300;
  color: var(--navy);
  letter-spacing: .1em;
}

/* ── Hero ── */
.hero {
  padding-top: calc(64px + clamp(4rem, 10vw, 8rem));
  padding-bottom: clamp(4rem, 8vw, 7rem);
  padding-left: var(--pad-x);
  padding-right: var(--pad-x);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: -20%; right: -10%;
  width: clamp(300px, 50vw, 600px);
  height: clamp(300px, 50vw, 600px);
  border-radius: 50%;
  background: radial-gradient(circle, rgba(200,223,240,.35) 0%, transparent 70%);
  pointer-events: none;
}
.hero-inner {
  max-width: var(--max);
  margin: 0 auto;
}
.hero-label { margin-bottom: 1rem; }
.hero-title { margin-bottom: 1.4rem; }
.hero-sub {
  font-size: clamp(1rem, 1.5vw, 1.1rem);
  color: var(--text-mid);
  font-weight: 300;
  max-width: 520px;
  line-height: 2;
  margin-bottom: 2.5rem;
}
.hero-cta { display: flex; gap: 1rem; flex-wrap: wrap; }

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .85rem 2rem;
  font-size: clamp(.82rem, 1.1vw, .88rem);
  letter-spacing: .14em;
  font-family: var(--font-sans);
  font-weight: 400;
  transition: var(--transition);
  border-radius: var(--radius);
  white-space: nowrap;
}
.btn-primary {
  background: var(--navy);
  color: var(--white);
  border: 1px solid var(--navy);
}
.btn-primary:hover {
  background: var(--blue-mid);
  border-color: var(--blue-mid);
}
.btn-outline {
  background: transparent;
  color: var(--navy);
  border: 1px solid var(--border);
}
.btn-outline:hover {
  border-color: var(--blue);
  color: var(--blue);
}
.btn-blue {
  background: var(--blue);
  color: var(--white);
  border: 1px solid var(--blue);
}
.btn-blue:hover {
  background: var(--blue-mid);
  border-color: var(--blue-mid);
}

/* ── Section Headers ── */
.section-header {
  margin-bottom: clamp(2.5rem, 5vw, 4rem);
}
.section-header .label {
  display: block;
  margin-bottom: .8rem;
}
.section-header h2 {
  margin-bottom: 1rem;
}
.section-header p {
  max-width: 560px;
  color: var(--text-mid);
  font-weight: 300;
  line-height: 2;
}

/* ── Cards ── */
.card {
  background: var(--white);
  border: 1px solid var(--border);
  padding: clamp(1.5rem, 3vw, 2.2rem);
  transition: box-shadow var(--transition), transform var(--transition);
}
.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: clamp(1rem, 2.5vw, 1.8rem);
}

/* ── Page Hero (inner pages) ── */
.page-hero {
  padding-top: calc(64px + clamp(3rem, 6vw, 5rem));
  padding-bottom: clamp(3rem, 6vw, 5rem);
  padding-left: var(--pad-x);
  padding-right: var(--pad-x);
  background: var(--off-white);
  border-bottom: 1px solid var(--border-light);
  position: relative;
  overflow: hidden;
}
.page-hero::before {
  content: '';
  position: absolute;
  top: -50%; right: -5%;
  width: 400px; height: 400px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(200,223,240,.2) 0%, transparent 70%);
  pointer-events: none;
}
.page-hero-inner {
  max-width: var(--max);
  margin: 0 auto;
}
.breadcrumb {
  display: flex;
  align-items: center;
  gap: .5rem;
  font-size: .72rem;
  color: var(--muted);
  letter-spacing: .06em;
  margin-bottom: 1.5rem;
}
.breadcrumb a { color: var(--muted); transition: color var(--transition); }
.breadcrumb a:hover { color: var(--blue); }
.breadcrumb span { color: var(--border); }

/* ── Divider ── */
.divider {
  width: 40px;
  height: 1px;
  background: var(--blue-light);
  margin: 1.5rem 0;
}

/* ── FAQ ── */
.faq-item {
  border-bottom: 1px solid var(--border-light);
}
.faq-question {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
  padding: 1.5rem 0;
  cursor: pointer;
  font-weight: 400;
  color: var(--navy);
  font-size: clamp(.95rem, 1.3vw, 1.02rem);
  line-height: 1.6;
}
.faq-question::after {
  content: '+';
  font-size: 1.4rem;
  font-weight: 300;
  color: var(--blue);
  flex-shrink: 0;
  transition: transform var(--transition);
}
.faq-item.open .faq-question::after { transform: rotate(45deg); }
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height .4s ease;
}
.faq-answer-inner {
  padding-bottom: 1.5rem;
  color: var(--text-mid);
  font-weight: 300;
  line-height: 2;
  font-size: clamp(.92rem, 1.2vw, .98rem);
}

/* ── CTA Section ── */
.cta-section {
  background: var(--navy);
  padding: clamp(3.5rem, 7vw, 6rem) var(--pad-x);
  text-align: center;
  position: relative;
  overflow: hidden;
}
.cta-section::before {
  content: '';
  position: absolute;
  top: -30%; left: 50%;
  transform: translateX(-50%);
  width: 600px; height: 600px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(74,144,184,.15) 0%, transparent 65%);
  pointer-events: none;
}
.cta-section h2 { color: var(--white); font-size: clamp(1.3rem, 3vw, 2rem); }
.cta-section p { color: rgba(255,255,255,.65); margin: 1rem auto 2.5rem; max-width: 500px; font-weight: 300; line-height: 2; }
.cta-section .btn-primary { background: var(--white); color: var(--navy); border-color: var(--white); }
.cta-section .btn-primary:hover { background: var(--blue-pale); border-color: var(--blue-pale); }
.cta-section .btn-outline { border-color: rgba(255,255,255,.3); color: rgba(255,255,255,.8); }
.cta-section .btn-outline:hover { border-color: var(--white); color: var(--white); }
.cta-btns { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }

/* ── Footer ── */
.site-footer {
  background: var(--navy);
  color: rgba(255,255,255,.6);
  padding: clamp(3rem, 6vw, 5rem) var(--pad-x) 2rem;
  font-size: .8rem;
}
.footer-inner {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: clamp(2rem, 5vw, 5rem);
  padding-bottom: 2.5rem;
  border-bottom: 1px solid rgba(255,255,255,.08);
  margin-bottom: 2rem;
}
.footer-brand .site-logo { color: rgba(255,255,255,.9); margin-bottom: .8rem; }
.footer-brand p { font-size: .72rem; line-height: 1.8; color: rgba(255,255,255,.4); max-width: 220px; }
.footer-nav-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 1.5rem;
}
.footer-nav-group h4 {
  color: rgba(255,255,255,.5);
  font-size: .65rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  font-family: var(--font-sans);
  font-weight: 400;
  margin-bottom: .8rem;
}
.footer-nav-group a {
  display: block;
  color: rgba(255,255,255,.55);
  font-size: .78rem;
  padding: .25rem 0;
  transition: color var(--transition);
  line-height: 1.6;
}
.footer-nav-group a:hover { color: rgba(255,255,255,.9); }
.footer-bottom {
  max-width: var(--max);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: .5rem;
  font-size: .7rem;
  color: rgba(255,255,255,.3);
}

/* ── Reveal Animation ── */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity .7s ease, transform .7s ease;
}
.reveal.revealed {
  opacity: 1;
  transform: none;
}

/* ── Utility ── */
.text-center { text-align: center; }
.mt-1 { margin-top: .5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-1 { margin-bottom: .5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }
.bg-off-white { background: var(--off-white); }
.bg-pale { background: var(--blue-pale); }

/* ── Responsive ── */
@media (max-width: 768px) {
  .nav-list { display: none; }
  .hamburger { display: flex; }
  .mobile-nav { display: flex; }
  .footer-inner { grid-template-columns: 1fr; }
  .hero-cta { flex-direction: column; align-items: flex-start; }
}
@media (max-width: 480px) {
  .card-grid { grid-template-columns: 1fr; }
  .cta-btns { flex-direction: column; align-items: center; }
}

@media(max-width:640px){.why-2col{grid-template-columns:1fr!important}}

/* ── 外部引用ブロック ── */
.citation-block {
  border: 1px solid var(--border-light);
  border-left: 4px solid var(--blue-light);
  background: var(--off-white);
  padding: 1.4rem 1.6rem 1.2rem;
  margin: 2rem 0;
}
.citation-block-header {
  display: flex;
  align-items: center;
  gap: .6rem;
  margin-bottom: .9rem;
  flex-wrap: wrap;
}
.citation-badge {
  font-size: .62rem;
  letter-spacing: .14em;
  font-weight: 500;
  padding: .18rem .65rem;
  background: var(--blue-pale);
  color: var(--blue);
  border: 1px solid rgba(74,144,184,.2);
  border-radius: 2px;
  white-space: nowrap;
}
.citation-source {
  font-size: .72rem;
  color: var(--muted);
  font-weight: 300;
  line-height: 1.5;
}
.citation-source a {
  color: var(--blue);
  text-decoration: underline;
  text-decoration-color: rgba(74,144,184,.3);
}
.citation-source a:hover { text-decoration-color: var(--blue); }
.citation-body {
  font-size: clamp(.88rem, 1.3vw, .94rem);
  color: var(--text);
  font-weight: 300;
  line-height: 1.9;
  border-left: 2px solid var(--blue-light);
  padding-left: 1rem;
  margin: .6rem 0 .9rem;
  font-style: italic;
}
.citation-wezu-note {
  margin-top: .8rem;
  padding-top: .8rem;
  border-top: 1px solid var(--border-light);
  font-size: .8rem;
  color: var(--text-mid);
  font-weight: 300;
  line-height: 1.8;
}
.citation-wezu-note strong {
  font-weight: 500;
  color: var(--navy);
  font-style: normal;
}
.citation-limit {
  margin-top: .6rem;
  font-size: .74rem;
  color: var(--muted);
  font-weight: 300;
  line-height: 1.7;
  padding: .5rem .8rem;
  background: var(--white);
  border: 1px solid var(--border-light);
}

/* ── 情報ソースブロック（SSOT準拠） ── */
.info-source-block {
  margin-top: clamp(2rem, 4vw, 3rem);
  border: 1px solid var(--border-light);
  background: var(--off-white);
  overflow: hidden;
}
.info-source-header {
  background: var(--navy);
  padding: .55rem 1.2rem;
  display: flex;
  align-items: center;
  gap: .6rem;
}
.info-source-header-label {
  font-size: .65rem;
  letter-spacing: .16em;
  color: rgba(255,255,255,.6);
  font-weight: 500;
}
.info-source-header-icon {
  font-size: .9rem;
  line-height: 1;
}
.info-source-body {
  padding: 1rem 1.2rem;
  display: flex;
  flex-direction: column;
  gap: .7rem;
}
.info-source-item {
  display: grid;
  grid-template-columns: 8rem 1fr;
  gap: .2rem .8rem;
  font-size: .8rem;
  border-bottom: 1px solid var(--border-light);
  padding-bottom: .7rem;
  align-items: start;
}
.info-source-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}
.info-source-item-label {
  font-size: .68rem;
  letter-spacing: .08em;
  color: var(--muted);
  font-weight: 500;
  padding-top: .1rem;
  white-space: nowrap;
}
.info-source-item-val {
  color: var(--text);
  font-weight: 300;
  line-height: 1.7;
}
.info-source-item-val a {
  color: var(--blue);
  word-break: break-all;
  font-size: .76rem;
}
.info-source-item-val a:hover { text-decoration: underline; }
.info-source-disclaimer {
  padding: .6rem 1.2rem;
  background: var(--white);
  border-top: 1px solid var(--border-light);
  font-size: .72rem;
  color: var(--muted);
  font-weight: 300;
  line-height: 1.7;
}
@media (max-width: 480px) {
  .info-source-item { grid-template-columns: 1fr; gap: .1rem; }
  .info-source-item-label { color: var(--blue); }
}

/* ── 研究情報ブロック（SSOT記事用） ── */
.research-info-block {
  margin: 2rem 0;
  border: 1px solid var(--border-light);
  overflow: hidden;
}
.research-info-label {
  background: var(--navy);
  color: rgba(255,255,255,.7);
  font-size: .65rem;
  letter-spacing: .14em;
  font-weight: 500;
  padding: .45rem 1.2rem;
}
.research-info-table {
  width: 100%;
  border-collapse: collapse;
  font-size: clamp(.78rem, 1.1vw, .84rem);
}
.research-info-table th {
  width: 7.5rem;
  background: var(--off-white);
  padding: .55rem .9rem;
  font-weight: 500;
  color: var(--muted);
  font-size: .72rem;
  letter-spacing: .04em;
  border-bottom: 1px solid var(--border-light);
  border-right: 1px solid var(--border-light);
  vertical-align: top;
  white-space: nowrap;
}
.research-info-table td {
  padding: .55rem .9rem;
  color: var(--text);
  font-weight: 300;
  line-height: 1.7;
  border-bottom: 1px solid var(--border-light);
  vertical-align: top;
}
.research-info-table td a {
  color: var(--blue);
  word-break: break-all;
  font-size: .76rem;
}
.research-info-table tr:last-child th,
.research-info-table tr:last-child td { border-bottom: none; }
.research-info-note {
  padding: .6rem 1.2rem;
  background: rgba(74,144,184,.04);
  font-size: .74rem;
  color: var(--text-mid);
  font-weight: 300;
  line-height: 1.7;
  border-top: 1px solid var(--border-light);
}
@media (max-width: 480px) {
  .research-info-table th { width: 5.5rem; white-space: normal; }
}