/* ============================================================
   Scinex — Science Media Stylesheet
   Aesthetic: Deep space editorial meets clean readability.
   Dark header/hero with a warm light body for reading comfort.
   ============================================================ */

/* --- Variables --- */
:root {
  --c-void: #0a0e1a;
  --c-deep: #111827;
  --c-slate: #1e293b;
  --c-muted: #64748b;
  --c-body: #334155;
  --c-text: #1e293b;
  --c-light: #f1f5f9;
  --c-surface: #ffffff;
  --c-accent: #06b6d4;       /* cyan — scientific, energetic */
  --c-accent-glow: #22d3ee;
  --c-accent-dim: #0e7490;
  --c-warm: #f59e0b;          /* amber accent for CTAs */
  --c-border: #e2e8f0;

  --font-display: 'Outfit', sans-serif;
  --font-body: 'Noto Sans JP', sans-serif;

  --w-content: 720px;
  --w-wide: 1120px;
  --radius: 12px;
  --radius-sm: 6px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font-body);
  color: var(--c-text);
  background: var(--c-light);
  line-height: 1.8;
}

a { color: var(--c-accent-dim); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--c-accent); }

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

/* --- Header --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--c-void);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  backdrop-filter: blur(12px);
}

.header-inner {
  max-width: var(--w-wide);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
}

.logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--c-accent), var(--c-accent-glow));
  color: var(--c-void);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 0.85rem;
  border-radius: 8px;
  letter-spacing: -0.02em;
}

.logo-text {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.25rem;
  color: #fff;
  letter-spacing: -0.02em;
}

.main-nav {
  display: flex;
  gap: 2rem;
}

.nav-link {
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 500;
  color: rgba(255,255,255,0.6);
  text-decoration: none;
  transition: color 0.2s;
  position: relative;
}

.nav-link:hover,
.nav-link.is-active {
  color: #fff;
}

.nav-link.is-active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--c-accent);
  border-radius: 1px;
}

/* Language switcher */
.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  margin-left: 1rem;
  padding-left: 1rem;
  border-left: 1px solid rgba(255,255,255,0.15);
  font-family: var(--font-display);
  font-size: 0.8rem;
  font-weight: 600;
}

.lang-current {
  color: #fff;
}

.lang-link {
  color: rgba(255,255,255,0.35);
  text-decoration: none;
  transition: color 0.2s;
}

.lang-link:hover {
  color: var(--c-accent-glow);
}

/* Mobile nav toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: #fff;
  border-radius: 1px;
  transition: transform 0.3s, opacity 0.3s;
}

@media (max-width: 768px) {
  .nav-toggle { display: flex; }
  .main-nav {
    display: none;
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background: var(--c-void);
    flex-direction: column;
    padding: 1rem 1.5rem 1.5rem;
    gap: 1rem;
    border-bottom: 1px solid rgba(255,255,255,0.06);
  }
  .main-nav.is-open { display: flex; }
}

/* --- Hero --- */
.hero {
  position: relative;
  background: var(--c-void);
  overflow: hidden;
  padding: 5rem 1.5rem 6rem;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 480px;
}

.hero-inner {
  position: relative;
  z-index: 2;
  max-width: var(--w-wide);
  text-align: center;
}

.hero-badge {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--c-accent-glow);
  border: 1px solid rgba(6,182,212,0.3);
  padding: 0.35rem 1rem;
  border-radius: 999px;
  margin-bottom: 1.5rem;
  animation: fadeInUp 0.6s ease both;
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 800;
  color: #fff;
  line-height: 1.3;
  letter-spacing: -0.03em;
  margin-bottom: 1.25rem;
  animation: fadeInUp 0.6s 0.1s ease both;
}

.hero-accent {
  background: linear-gradient(135deg, var(--c-accent-glow), var(--c-warm));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 1.1rem;
  color: rgba(255,255,255,0.6);
  max-width: 540px;
  margin: 0 auto 2rem;
  line-height: 1.7;
  animation: fadeInUp 0.6s 0.2s ease both;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInUp 0.6s 0.3s ease both;
}

/* Hero decoration — atom orbits */
.hero-decoration {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 500px;
  height: 500px;
  opacity: 0.12;
}

.nucleus {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 8px;
  height: 8px;
  background: var(--c-accent-glow);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  box-shadow: 0 0 30px var(--c-accent);
}

.orbit {
  position: absolute;
  top: 50%;
  left: 50%;
  border: 1px solid var(--c-accent);
  border-radius: 50%;
  transform: translate(-50%, -50%);
}

.orbit-1 { width: 200px; height: 200px; animation: spin 20s linear infinite; }
.orbit-2 { width: 320px; height: 320px; animation: spin 30s linear infinite reverse; transform: translate(-50%, -50%) rotate(60deg); }
.orbit-3 { width: 440px; height: 440px; animation: spin 40s linear infinite; transform: translate(-50%, -50%) rotate(-30deg); }

.orbit::after {
  content: '';
  position: absolute;
  top: -4px;
  left: 50%;
  width: 8px;
  height: 8px;
  background: var(--c-accent-glow);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--c-accent);
}

@keyframes spin {
  to { transform: translate(-50%, -50%) rotate(360deg); }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* --- Buttons --- */
.btn-primary {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--c-void);
  background: linear-gradient(135deg, var(--c-accent), var(--c-accent-glow));
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius);
  text-decoration: none;
  transition: transform 0.2s, box-shadow 0.2s;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(6,182,212,0.3);
  color: var(--c-void);
}

.btn-secondary {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 600;
  color: #fff;
  border: 1px solid rgba(255,255,255,0.2);
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius);
  text-decoration: none;
  transition: border-color 0.2s, background 0.2s;
}

.btn-secondary:hover {
  border-color: rgba(255,255,255,0.4);
  background: rgba(255,255,255,0.05);
  color: #fff;
}

.btn-substack {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--c-void);
  background: var(--c-warm);
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius);
  text-decoration: none;
  transition: transform 0.2s, box-shadow 0.2s;
}

.btn-substack:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(245,158,11,0.3);
  color: var(--c-void);
}

/* --- Sections --- */
.section-inner {
  max-width: var(--w-wide);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section-title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 2rem;
  position: relative;
  padding-left: 1rem;
}

.section-title::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.15em;
  bottom: 0.15em;
  width: 3px;
  background: linear-gradient(180deg, var(--c-accent), var(--c-accent-glow));
  border-radius: 2px;
}

.section-more {
  text-align: center;
  margin-top: 2.5rem;
}

/* --- Posts Grid --- */
.latest-posts, .related-posts {
  padding: 4rem 0;
}

.posts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}

.post-card {
  background: var(--c-surface);
  border-radius: var(--radius);
  border: 1px solid var(--c-border);
  overflow: hidden;
  transition: transform 0.2s, box-shadow 0.2s;
}

.post-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(0,0,0,0.08);
}

.post-card-link {
  display: block;
  padding: 1.5rem;
  text-decoration: none;
  color: inherit;
}

.post-card-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.post-card-meta time {
  font-size: 0.8rem;
  color: var(--c-muted);
  font-family: var(--font-display);
}

.post-card-cat {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--c-accent-dim);
  background: rgba(6,182,212,0.08);
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  font-family: var(--font-display);
}

.post-card-title {
  font-family: var(--font-body);
  font-size: 1.1rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--c-text);
  margin-bottom: 0.5rem;
}

.post-card-excerpt {
  font-size: 0.9rem;
  color: var(--c-muted);
  line-height: 1.7;
  margin-bottom: 0.75rem;
}

.post-card-readmore {
  font-family: var(--font-display);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--c-accent);
}

/* --- Article Page --- */
.article-header {
  background: var(--c-void);
  padding: 4rem 1.5rem 3rem;
}

.article-header-inner {
  max-width: var(--w-content);
  margin: 0 auto;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
  flex-wrap: wrap;
}

.article-meta time {
  font-size: 0.85rem;
  color: rgba(255,255,255,0.5);
  font-family: var(--font-display);
}

.article-cat {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--c-accent-glow);
  background: rgba(6,182,212,0.12);
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  text-decoration: none;
}

.article-title {
  font-family: var(--font-body);
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  font-weight: 700;
  color: #fff;
  line-height: 1.4;
  letter-spacing: -0.01em;
  margin-bottom: 1rem;
}

.article-lead {
  font-size: 1.05rem;
  color: rgba(255,255,255,0.65);
  line-height: 1.7;
  margin-bottom: 1rem;
}

.article-source {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.4);
}

.article-source a {
  color: rgba(255,255,255,0.6);
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* Article Body */
.article-body {
  max-width: var(--w-content);
  margin: 0 auto;
  padding: 3rem 1.5rem 4rem;
}

.article-content h2 {
  font-family: var(--font-body);
  font-size: 1.4rem;
  font-weight: 700;
  margin: 2.5rem 0 1rem;
  padding-left: 0.75rem;
  border-left: 3px solid var(--c-accent);
  line-height: 1.4;
}

.article-content h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin: 2rem 0 0.75rem;
}

.article-content p {
  margin-bottom: 1.5rem;
  font-size: 1rem;
  line-height: 2;
  color: var(--c-body);
}

.article-content blockquote {
  margin: 2rem 0;
  padding: 1.25rem 1.5rem;
  background: rgba(6,182,212,0.04);
  border-left: 3px solid var(--c-accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--c-body);
  font-style: italic;
}

.article-content ul, .article-content ol {
  margin: 1rem 0 1.5rem 1.5rem;
}

.article-content li {
  margin-bottom: 0.5rem;
  line-height: 1.8;
}

.article-content code {
  font-size: 0.9em;
  background: rgba(0,0,0,0.05);
  padding: 0.15em 0.4em;
  border-radius: 4px;
}

.article-content figure {
  margin: 2rem 0;
}

.article-content figcaption {
  font-size: 0.85rem;
  color: var(--c-muted);
  text-align: center;
  margin-top: 0.5rem;
}

/* Tags */
.article-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 2rem 0;
  padding-top: 2rem;
  border-top: 1px solid var(--c-border);
}

.tag {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--c-muted);
  background: rgba(0,0,0,0.04);
  padding: 0.3rem 0.75rem;
  border-radius: 999px;
  text-decoration: none;
  transition: color 0.2s, background 0.2s;
}

.tag:hover {
  color: var(--c-accent);
  background: rgba(6,182,212,0.08);
}

/* Share */
.article-share {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin: 1.5rem 0;
}

.share-label {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--c-muted);
}

.share-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  font-size: 0.8rem;
  font-weight: 700;
  text-decoration: none;
  transition: transform 0.2s;
}

.share-btn:hover { transform: scale(1.1); }

.share-twitter { background: #1d9bf0; color: #fff; }
.share-facebook { background: #1877f2; color: #fff; }
.share-hatena { background: #00a4de; color: #fff; }

/* Article CTA */
.article-cta {
  max-width: var(--w-content);
  margin: 0 auto;
  padding: 0 1.5rem 4rem;
}

.article-cta-inner {
  text-align: center;
  background: var(--c-deep);
  border-radius: var(--radius);
  padding: 2.5rem 2rem;
}

.article-cta-text {
  font-size: 1.1rem;
  color: rgba(255,255,255,0.8);
  margin-bottom: 1.25rem;
}

/* Ad Slot */
.ad-slot {
  margin: 2rem 0;
  min-height: 100px;
}

/* --- About CTA on Home --- */
.about-cta {
  padding: 0 0 5rem;
}

.about-cta-card {
  background: var(--c-deep);
  border-radius: var(--radius);
  padding: 3rem 2.5rem;
  text-align: center;
  color: #fff;
}

.about-cta-card h2 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.about-cta-card p {
  color: rgba(255,255,255,0.65);
  line-height: 1.8;
  max-width: 600px;
  margin: 0 auto 1.5rem;
}

/* --- List Page --- */
.list-page {
  padding: 3rem 0 5rem;
}

.page-title {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 0.5rem;
}

.page-desc {
  color: var(--c-muted);
  margin-bottom: 2.5rem;
}

/* Category Filter */
.category-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 2rem;
}

.filter-btn {
  font-family: var(--font-display);
  font-size: 0.82rem;
  font-weight: 600;
  padding: 0.4rem 1rem;
  border-radius: 999px;
  border: 1px solid var(--c-border);
  background: var(--c-surface);
  color: var(--c-muted);
  cursor: pointer;
  transition: all 0.2s ease;
}

.filter-btn:hover {
  border-color: var(--c-accent);
  color: var(--c-accent);
}

.filter-btn.active {
  background: var(--c-accent);
  border-color: var(--c-accent);
  color: #fff;
}

.filter-btn.active:hover {
  background: var(--c-accent-dim);
  border-color: var(--c-accent-dim);
  color: #fff;
}

/* Pagination */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--c-border);
}

.pagination-link {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--c-accent);
}

.pagination-info {
  font-family: var(--font-display);
  font-size: 0.85rem;
  color: var(--c-muted);
}

/* --- Footer --- */
.site-footer {
  background: var(--c-void);
  padding: 4rem 1.5rem;
}

.footer-inner {
  max-width: var(--w-wide);
  margin: 0 auto;
}

.footer-cta {
  text-align: center;
  padding-bottom: 3rem;
  margin-bottom: 3rem;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

.footer-cta-text {
  font-size: 1.1rem;
  color: rgba(255,255,255,0.7);
  margin-bottom: 1.25rem;
}

.footer-meta {
  text-align: center;
}

.footer-meta .logo-mark {
  margin-bottom: 0.5rem;
}

.footer-tagline {
  font-size: 0.9rem;
  color: rgba(255,255,255,0.4);
  margin-top: 0.75rem;
}

.footer-links {
  display: flex;
  gap: 1.2rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 1rem;
}

.footer-links a {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.5);
  text-decoration: none;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: rgba(255,255,255,0.85);
}

.footer-copy {
  font-size: 0.75rem;
  color: rgba(255,255,255,0.25);
  margin-top: 1rem;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .hero { padding: 3rem 1.5rem 4rem; min-height: auto; }
  .hero-decoration { width: 300px; height: 300px; }
  .posts-grid { grid-template-columns: 1fr; }
  .about-cta-card { padding: 2rem 1.5rem; }
  .article-header { padding: 3rem 1.5rem 2rem; }
}

@media (max-width: 480px) {
  .hero-title { font-size: 1.75rem; }
  .hero-desc { font-size: 0.95rem; }
  .post-card-link { padding: 1.25rem; }
}