/* ============================================================
   Yanchainuu - style.css
   ============================================================ */

/* ---------- CSS Variables ---------- */
:root {
  --color-navy:  #1a2e4a;
  --color-red:   #640818;
  --color-beige: #EBD0C0;
  --color-cream: #FAF6F2;
  --color-white: #FFFFFF;
  --color-text:  #333333;
  --color-gray:  #888888;
  --color-border: #e8ddd6;

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

  --header-height: 72px;
  --radius: 12px;
  --shadow: 0 4px 24px rgba(26, 46, 74, 0.08);
  --shadow-hover: 0 8px 32px rgba(26, 46, 74, 0.15);
  --transition: 0.25s ease;

  --container-width: 1160px;
  --container-padding: 24px;
}

/* ---------- 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: 1rem;
  line-height: 1.8;
  color: var(--color-text);
  background: var(--color-white);
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
button { background: none; border: none; cursor: pointer; }

/* ---------- Utilities ---------- */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}
.section-padding { padding: 96px 0; }
.text-center { text-align: center; }

.section-label {
  display: block;
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.22em;
  color: var(--color-gray);
  margin-bottom: 12px;
}
.section-heading {
  font-family: var(--font-serif);
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 700;
  color: var(--color-navy);
  line-height: 1.5;
  letter-spacing: 0.06em;
  margin-bottom: 48px;
}
.text-center .section-label,
.text-center .section-heading { text-align: center; }

/* ---------- Buttons ---------- */
.btn-primary {
  display: inline-block;
  background: var(--color-navy);
  color: var(--color-white);
  font-family: var(--font-serif);
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  padding: 15px 40px;
  transition: background var(--transition), transform var(--transition);
}
.btn-primary:hover {
  background: var(--color-red);
  transform: translateY(-1px);
}
.btn-primary.btn-large {
  padding: 18px 56px;
  font-size: 1rem;
}
.btn-outline {
  display: inline-block;
  border: 1.5px solid var(--color-navy);
  color: var(--color-navy);
  font-family: var(--font-serif);
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  padding: 12px 32px;
  transition: background var(--transition), color var(--transition);
}
.btn-outline:hover {
  background: var(--color-navy);
  color: var(--color-white);
}
.btn-secondary {
  display: inline-block;
  color: var(--color-navy);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  border-bottom: 1px solid var(--color-navy);
  padding-bottom: 2px;
  transition: opacity var(--transition);
}
.btn-secondary:hover { opacity: 0.65; }

/* ---------- Image Placeholder ---------- */
.img-placeholder {
  width: 100%;
  height: 100%;
  min-height: 320px;
  background: linear-gradient(135deg, var(--color-beige) 0%, var(--color-cream) 60%, #d4b9a5 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-gray);
  font-size: 0.82rem;
  font-family: var(--font-sans);
  letter-spacing: 0.05em;
}

/* ---------- Fade-in animation ---------- */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   HEADER
   ============================================================ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  z-index: 1000;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.site-header.scrolled {
  border-color: var(--color-border);
  box-shadow: 0 2px 16px rgba(26, 46, 74, 0.06);
}
.header-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
  height: 100%;
  display: flex;
  align-items: center;
  gap: 40px;
}
.logo {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-navy);
  letter-spacing: 0.08em;
  white-space: nowrap;
  flex-shrink: 0;
}
.main-nav { flex: 1; }
.main-nav ul {
  display: flex;
  gap: 32px;
}
.main-nav a {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text);
  letter-spacing: 0.06em;
  position: relative;
  padding-bottom: 2px;
}
.main-nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--color-navy);
  transition: width var(--transition);
}
.main-nav a:hover::after { width: 100%; }

.btn-header-shop {
  flex-shrink: 0;
  background: var(--color-navy);
  color: var(--color-white);
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  padding: 9px 22px;
  transition: background var(--transition);
}
.btn-header-shop:hover { background: var(--color-red); }

.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  padding: 4px;
  margin-left: auto;
  flex-shrink: 0;
}
.hamburger span {
  display: block;
  width: 100%;
  height: 1.5px;
  background: var(--color-navy);
  transition: transform var(--transition), opacity var(--transition);
  transform-origin: center;
}
.hamburger.active span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.hamburger.active span:nth-child(2) { opacity: 0; }
.hamburger.active span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* ---------- Mobile Nav ---------- */
.mobile-nav-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(26, 46, 74, 0.4);
  z-index: 998;
  opacity: 0;
  transition: opacity var(--transition);
}
.mobile-nav-overlay.active { opacity: 1; }

.mobile-nav {
  position: fixed;
  top: var(--header-height);
  right: 0;
  bottom: 0;
  width: min(320px, 85vw);
  background: var(--color-white);
  z-index: 999;
  transform: translateX(100%);
  transition: transform 0.3s ease;
  padding: 32px 28px;
  overflow-y: auto;
}
.mobile-nav.active { transform: translateX(0); }
.mobile-nav ul { display: flex; flex-direction: column; gap: 0; }
.mobile-nav li { border-bottom: 1px solid var(--color-border); }
.mobile-nav-link {
  display: block;
  padding: 18px 0;
  font-family: var(--font-serif);
  font-size: 1rem;
  color: var(--color-navy);
  letter-spacing: 0.08em;
  transition: opacity var(--transition);
}
.mobile-nav-link:hover { opacity: 0.6; }
.mobile-nav-shop {
  margin-top: 8px;
  font-weight: 700;
  color: var(--color-red);
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: center;
  padding-top: var(--header-height);
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.hero-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center right;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to right,
    rgba(235, 208, 192, 0.96) 0%,
    rgba(235, 208, 192, 0.80) 45%,
    rgba(235, 208, 192, 0.10) 75%,
    transparent 100%
  );
}
.hero-content {
  position: relative;
  z-index: 1;
  max-width: 580px;
  padding-top: 40px;
  padding-bottom: 80px;
}
.hero-eyebrow {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  color: var(--color-navy);
  margin-bottom: 20px;
  opacity: 0.75;
}
.hero-heading {
  font-family: var(--font-serif);
  font-size: clamp(2.8rem, 6vw, 5rem);
  font-weight: 700;
  color: var(--color-navy);
  line-height: 1.35;
  letter-spacing: 0.1em;
  margin-bottom: 24px;
}
.hero-sub {
  font-family: var(--font-sans);
  font-size: clamp(0.85rem, 1.5vw, 1rem);
  color: var(--color-navy);
  line-height: 2;
  letter-spacing: 0.06em;
  margin-bottom: 44px;
  opacity: 0.85;
}
.btn-arrow { display: inline-block; margin-left: 4px; transition: transform var(--transition); }
.btn-primary:hover .btn-arrow { transform: translateX(4px); }

/* ============================================================
   TRUST BADGES
   ============================================================ */
.trust-badges {
  background: var(--color-navy);
  padding: 0;
}
.badges-inner {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
}
.badge-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 28px 36px;
  color: var(--color-white);
  text-align: center;
  position: relative;
  flex: 0 0 auto;
}
.badge-item + .badge-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 25%;
  height: 50%;
  width: 1px;
  background: rgba(255, 255, 255, 0.2);
}
.badge-icon {
  font-size: 1.8rem;
  line-height: 1;
  margin-bottom: 10px;
  display: block;
}
.badge-label {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  line-height: 1.6;
}
.badge-label small {
  font-size: 0.72rem;
  opacity: 0.8;
}

/* ============================================================
   CONCEPT
   ============================================================ */
.concept { background: var(--color-cream); }
.concept-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}
.concept-text .section-heading { margin-bottom: 28px; }
.concept-text p {
  font-size: 0.95rem;
  line-height: 2;
  color: var(--color-text);
  margin-bottom: 20px;
}
.concept-text p:last-of-type { margin-bottom: 40px; }
.concept-image {
  border-radius: var(--radius);
  overflow: hidden;
  aspect-ratio: 4 / 5;
  box-shadow: var(--shadow);
}
.concept-image .img-placeholder { min-height: 100%; }

/* ============================================================
   FEATURES
   ============================================================ */
.features { background: var(--color-white); }
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}
.feature-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 40px 32px;
  text-align: center;
  transition: box-shadow var(--transition), transform var(--transition);
}
.feature-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-4px);
}
.feature-icon {
  font-size: 2.4rem;
  display: block;
  margin-bottom: 20px;
  line-height: 1;
}
.feature-card h3 {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-navy);
  letter-spacing: 0.06em;
  margin-bottom: 14px;
}
.feature-card p {
  font-size: 0.875rem;
  line-height: 1.9;
  color: var(--color-gray);
}

/* ============================================================
   COLLECTION
   ============================================================ */
.collection { background: var(--color-cream); }
.collection-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-bottom: 56px;
}
.collection-card {
  background: var(--color-white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition), transform var(--transition);
}
.collection-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-4px);
}
.collection-img {
  position: relative;
  aspect-ratio: 1 / 1;
  overflow: hidden;
}
.collection-img .img-placeholder {
  min-height: 100%;
  height: 100%;
}
.collection-img-overlay {
  position: absolute;
  top: 14px;
  left: 14px;
  background: var(--color-red);
  color: var(--color-white);
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  padding: 4px 10px;
}
.collection-card-body {
  padding: 24px;
}
.collection-card-body h3 {
  font-family: var(--font-serif);
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-navy);
  letter-spacing: 0.06em;
  margin-bottom: 8px;
}
.collection-card-body p {
  font-size: 0.82rem;
  color: var(--color-gray);
  margin-bottom: 20px;
  line-height: 1.7;
}
.collection-cta { text-align: center; }

/* ============================================================
   SNS
   ============================================================ */
.sns-section { background: var(--color-cream); border-top: 1px solid var(--color-border); }
.sns-section .section-heading { margin-bottom: 12px; }
.sns-sub {
  font-size: 0.95rem;
  color: var(--color-gray);
  margin-bottom: 44px;
  letter-spacing: 0.04em;
}
.sns-buttons {
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
}
.sns-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 36px;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  transition: transform var(--transition), opacity var(--transition);
}
.sns-btn:hover { transform: translateY(-2px); opacity: 0.85; }
.sns-btn i { font-size: 1.2rem; }

.sns-instagram {
  background: linear-gradient(135deg, #f09433 0%, #e6683c 25%, #dc2743 50%, #cc2366 75%, #bc1888 100%);
  color: var(--color-white);
}
.sns-tiktok {
  background: #010101;
  color: var(--color-white);
}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  background: var(--color-navy);
  color: var(--color-white);
  padding: 56px 0 40px;
}
.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 28px;
  text-align: center;
}
.footer-logo {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 0.1em;
}
.footer-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 32px;
}
.footer-nav a {
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  opacity: 0.75;
  transition: opacity var(--transition);
}
.footer-nav a:hover { opacity: 1; }
.footer-copy {
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  opacity: 0.5;
}

/* ============================================================
   RESPONSIVE — Tablet ( ≤ 900px )
   ============================================================ */
@media (max-width: 900px) {
  :root { --container-padding: 20px; }
  .section-padding { padding: 72px 0; }

  .main-nav, .btn-header-shop { display: none; }
  .hamburger { display: flex; }

  .mobile-nav-overlay { display: block; }

  .concept-inner {
    grid-template-columns: 1fr;
    gap: 48px;
  }
  .concept-image { max-width: 480px; margin: 0 auto; width: 100%; }

  .features-grid { grid-template-columns: 1fr 1fr; gap: 20px; }
  .collection-grid { grid-template-columns: 1fr 1fr; gap: 20px; }
}

/* ============================================================
   RESPONSIVE — Mobile ( ≤ 600px )
   ============================================================ */
@media (max-width: 600px) {
  :root {
    --header-height: 60px;
    --container-padding: 20px;
  }
  .section-padding { padding: 56px 0; }
  .section-heading { margin-bottom: 32px; }

  /* Hero */
  .hero { min-height: 100svh; align-items: flex-end; }
  .hero-img { object-position: center top; }
  .hero-overlay {
    background: linear-gradient(
      to top,
      rgba(235, 208, 192, 0.98) 0%,
      rgba(235, 208, 192, 0.85) 40%,
      rgba(235, 208, 192, 0.20) 70%,
      transparent 100%
    );
  }
  .hero-content {
    padding-top: 0;
    padding-bottom: 56px;
  }
  .btn-primary { display: block; text-align: center; }

  /* Badges */
  .badge-item {
    flex: 0 0 33.333%;
    padding: 20px 8px;
  }
  .badge-item + .badge-item::before { display: none; }
  .badge-label { font-size: 0.70rem; }

  /* Features */
  .features-grid { grid-template-columns: 1fr; }
  .feature-card { padding: 32px 24px; }

  /* Collection */
  .collection-grid { grid-template-columns: 1fr; }

  /* SNS */
  .sns-buttons { flex-direction: column; align-items: center; }
  .sns-btn { width: 240px; justify-content: center; }

  /* Footer */
  .footer-nav { gap: 8px 20px; }
}