/* === yushutan.top — SR400 × Coffee === */

:root {
  --bg: #f7f4ee;
  --bg-card: #ffffff;
  --bg-elevated: #f5f0e6;
  --text: #2c2c2c;
  --text-dim: #888;
  --accent: #8b6914;
  --accent-navy: #122b6e;
  --accent-dim: rgba(139,105,20,0.08);
  --border: #e8e3d8;
  --border-dark: #d5cebc;
  --ink: #1a1a1a;
  --font-en: "Georgia", "Times New Roman", serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "Segoe UI", sans-serif;
  --font-jp: "Hiragino Mincho ProN", "Yu Mincho", "MS Mincho", serif;
  --max-width: 1100px;
  --nav-height: 60px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

/* === Typography === */
h1, h2, h3, h4 {
  font-family: var(--font-en);
  font-weight: 400;
  color: var(--ink);
  letter-spacing: 1px;
}
.serif { font-family: var(--font-en); }
a { color: var(--accent); text-decoration: none; transition: opacity 0.3s; }
a:hover { opacity: 0.7; }

/* === Navigation === */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  height: var(--nav-height);
  background: rgba(247,244,238,0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--max-width); margin: 0 auto; padding: 0 2rem;
  height: 100%;
  display: flex; justify-content: space-between; align-items: center;
}
.nav-brand {
  font-family: var(--font-en);
  font-size: 1.2rem; color: var(--ink); letter-spacing: 2px;
}
.nav-links {
  display: flex; gap: 2.5rem; align-items: center; list-style: none;
}
.nav-links a {
  font-size: 0.8rem; color: var(--text-dim);
  text-transform: uppercase; letter-spacing: 1.5px;
  transition: color 0.3s; font-family: var(--font-sans);
}
.nav-links a:hover, .nav-links a.active { color: var(--ink); }
.lang-toggle {
  background: none; border: 1px solid var(--border-dark);
  color: var(--text-dim); padding: 3px 10px; font-size: 0.7rem;
  cursor: pointer; letter-spacing: 1px; transition: all 0.3s;
  font-family: var(--font-sans);
}
.lang-toggle:hover { border-color: var(--ink); color: var(--ink); }

/* === Hero with Photo === */
.hero {
  min-height: 100vh;
  display: flex; flex-direction: column;
  justify-content: center; align-items: center;
  position: relative; overflow: hidden;
}

.hero-photo {
  position: absolute; inset: 0;
  background: url('/assets/images/hero/sr400_hero.jpg?v=4') center/cover no-repeat;
  opacity: 1;
}

.hero-overlay {
  position: absolute; inset: 0;
  background: linear-gradient(
    rgba(247,244,238,0.15) 0%,
    rgba(247,244,238,0.1) 50%,
    rgba(247,244,238,0.5) 85%,
    rgba(247,244,238,0.85) 100%
  );
}

.hero-content {
  position: relative; z-index: 1;
  text-align: center;
  text-shadow: 0 1px 4px rgba(0,0,0,0.15);
}

.hero-line {
  width: 1px; height: 60px;
  background: var(--accent);
  margin: 0 auto 2.5rem;
  opacity: 0.8;
}

.hero-title {
  font-size: clamp(2.5rem, 7vw, 5rem);
  font-weight: 400;
  color: var(--ink);
  line-height: 1.15;
  margin-bottom: 1.2rem;
  letter-spacing: 2px;
}
.hero-title em { font-style: italic; color: var(--accent); }

.hero-divider {
  width: 30px; height: 1px;
  background: var(--accent);
  margin: 1.5rem auto;
  opacity: 0.6;
}

.hero-sub {
  font-family: var(--font-sans);
  font-size: 0.85rem; color: var(--text-dim);
  letter-spacing: 2px; text-transform: uppercase;
}

/* === Split Section === */
.split-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: 80vh;
}

.split-card {
  position: relative;
  display: flex; flex-direction: column;
  justify-content: center; align-items: center;
  text-align: center; padding: 4rem;
  cursor: pointer; overflow: hidden;
  transition: all 0.4s ease;
}
.split-card::before {
  content: ''; position: absolute; inset: 0;
  opacity: 0; transition: opacity 0.4s; z-index: 0;
}
.split-card:hover::before { opacity: 1; }

.split-card.sr400 {
  background: #111b2e; color: #bcc5d4;
}
.split-card.sr400::before {
  background: radial-gradient(circle at center, rgba(139,105,20,0.1) 0%, transparent 70%);
}
.split-card.sr400 h2, .split-card.sr400 .split-num { color: #fff; }
.split-card.sr400 .split-divider { background: var(--accent); }
.split-card.sr400 .split-arrow { color: var(--accent); }

.split-card.coffee {
  background: #f5f0e6; color: var(--text-dim);
}
.split-card.coffee::before {
  background: radial-gradient(circle at center, rgba(139,105,20,0.05) 0%, transparent 70%);
}
.split-card.coffee h2, .split-card.coffee .split-num { color: var(--ink); }
.split-card.coffee .split-divider { background: var(--accent); }
.split-card.coffee .split-arrow { color: var(--accent); }

.split-num {
  font-size: 0.6rem; letter-spacing: 4px;
  text-transform: uppercase; margin-bottom: 1.5rem;
  position: relative; z-index: 1;
}
.split-title {
  font-size: clamp(1.8rem, 3vw, 2.5rem);
  margin-bottom: 1rem; position: relative; z-index: 1;
  line-height: 1.2;
}
.split-divider {
  width: 30px; height: 1px;
  margin-bottom: 2rem; position: relative; z-index: 1;
}
.split-arrow {
  font-size: 0.7rem; letter-spacing: 2px;
  text-transform: uppercase; position: relative; z-index: 1;
}

/* === Section Common === */
.section {
  padding: 6rem 2rem;
  max-width: var(--max-width);
  margin: 0 auto;
}
.section-label {
  font-size: 0.6rem; letter-spacing: 4px;
  text-transform: uppercase; color: var(--text-dim);
  margin-bottom: 0.5rem;
}
.section-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  color: var(--ink); margin-bottom: 1rem;
  letter-spacing: 2px;
}
.section-divider {
  width: 30px; height: 1px;
  background: var(--accent);
  margin-bottom: 3rem; opacity: 0.5;
}

/* === Page Header === */
.page-header {
  padding: 8rem 2rem 3rem;
  text-align: center;
}
.page-header h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  letter-spacing: 2px;
}
.page-header .section-label { margin-bottom: 1rem; }

/* === Gallery Grid === */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 2px; background: var(--border);
}
.gallery-item {
  position: relative; overflow: hidden; cursor: pointer;
  aspect-ratio: 3/4; background: var(--bg-card);
}
.gallery-item img {
  width: 100%; height: 100%;
  object-fit: cover; transition: transform 0.5s;
}
.gallery-item:hover img { transform: scale(1.04); }
.gallery-caption {
  position: absolute; bottom: 0; left: 0; right: 0;
  padding: 2rem 1.2rem 1.2rem;
  background: linear-gradient(transparent, rgba(0,0,0,0.6));
  color: #fff; opacity: 0; transition: opacity 0.3s;
}
.gallery-item:hover .gallery-caption { opacity: 1; }
.gallery-caption h4 { font-size: 0.9rem; color: #fff; margin-bottom: 0.2rem; }
.gallery-caption p { font-size: 0.75rem; color: rgba(255,255,255,0.7); }

/* === Lightbox === */
.lightbox {
  display: none; position: fixed; inset: 0;
  background: rgba(255,255,255,0.97); z-index: 2000;
  align-items: center; justify-content: center;
}
.lightbox.active { display: flex; }
.lightbox img {
  max-width: 90vw; max-height: 90vh;
  object-fit: contain; box-shadow: 0 2px 20px rgba(0,0,0,0.08);
}
.lightbox-close {
  position: absolute; top: 2rem; right: 2rem;
  width: 40px; height: 40px; border: 1px solid #ccc;
  background: none; color: #555; font-size: 1.1rem;
  cursor: pointer; display: flex; align-items: center; justify-content: center;
  transition: all 0.3s;
}
.lightbox-close:hover { border-color: var(--ink); color: var(--ink); }
.lightbox-caption {
  position: absolute; bottom: 2rem;
  color: var(--text-dim); font-size: 0.8rem;
}

/* === Feature Grid === */
.feature-grid {
  display: grid; grid-template-columns: repeat(2, 1fr);
  gap: 1px; background: var(--border);
}
.feature-card { background: var(--bg-card); overflow: hidden; }
.feature-card img {
  width: 100%; aspect-ratio: 16/10; object-fit: cover;
}
.feature-card-body { padding: 2rem; }
.feature-card-body h3 { font-size: 1.1rem; margin-bottom: 0.8rem; }
.feature-card-body p { color: #666; font-size: 0.9rem; line-height: 1.8; }

/* === Volume List === */
.volume-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1px; background: var(--border);
}
.volume-card {
  background: #fff; padding: 2.5rem 2rem;
  text-align: center; transition: background 0.3s;
  display: block; text-decoration: none; color: inherit;
}
.volume-card:hover { background: var(--bg-elevated); }
.volume-card h3 { font-size: 1.5rem; margin-bottom: 0.3rem; color: var(--ink); }
.volume-card .vol-num { font-size: 0.65rem; color: var(--accent); letter-spacing: 3px; margin-bottom: 0.8rem; }
.volume-card p { font-size: 0.85rem; color: #888; line-height: 1.6; }
.volume-card .arrow { color: var(--accent); font-size: 0.7rem; letter-spacing: 2px; margin-top: 1rem; display: block; }

/* === Volume Hero === */
.volume-hero { padding: 7rem 2rem 2rem; text-align: center; max-width: 600px; margin: 0 auto; }
.volume-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 2px; background: #ddd;
}
.volume-grid .page-item {
  aspect-ratio: 3/4; overflow: hidden;
  background: var(--bg); cursor: pointer; position: relative;
}
.volume-grid .page-item img {
  width: 100%; height: 100%;
  object-fit: cover; transition: transform 0.3s;
}
.volume-grid .page-item:hover img { transform: scale(1.03); }
.page-num {
  position: absolute; top: 4px; right: 6px;
  font-size: 0.6rem; color: rgba(0,0,0,0.3);
  background: rgba(255,255,255,0.7); padding: 1px 4px;
}
.back-link {
  display: inline-block; margin: 1rem 0 2rem;
  font-size: 0.75rem; color: var(--text-dim); letter-spacing: 1px;
}

/* === Footer === */
footer {
  border-top: 1px solid var(--border);
  padding: 3rem 2rem; text-align: center;
}
footer .brand {
  font-family: var(--font-en);
  font-size: 1.1rem; color: var(--ink);
  letter-spacing: 2px; margin-bottom: 0.5rem;
}

/* === Responsive === */
@media (max-width: 768px) {
  .split-section { grid-template-columns: 1fr; }
  .split-card { min-height: 50vh; }
  .feature-grid { grid-template-columns: 1fr; }
  .gallery-grid { grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); }
  .volume-grid { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); }
  .volume-list { grid-template-columns: 1fr; }
  .section { padding: 4rem 1.5rem; }
  .hero { padding: 4rem 1.5rem; }
  .page-header { padding: 6rem 1.5rem 2rem; }
}
@media (max-width: 480px) {
  .nav-links { gap: 1rem; }
  .nav-links a { font-size: 0.7rem; letter-spacing: 1px; }
  .split-card { padding: 3rem 1.5rem; }
}