/* ===================================================
   時代で巡るメトロポリタン美術館 — Main Stylesheet
   =================================================== */

/* ---------- CSS Custom Properties ---------- */
:root {
  /* Era Colors */
  --c-egypt:        #c4922a;
  --c-greece:       #4a90c4;
  --c-medieval:     #7c5cbf;
  --c-renaissance:  #b8860b;
  --c-baroque:      #c0392b;
  --c-impressionism:#2e8b57;

  /* Base Colors */
  --c-bg:           #0e0e0e;
  --c-surface:      #161616;
  --c-surface-2:    #1e1e1e;
  --c-surface-3:    #272727;
  --c-border:       rgba(255,255,255,0.08);
  --c-text:         #e8e4dd;
  --c-text-muted:   #9a9188;
  --c-text-light:   #bfb9af;
  --c-white:        #ffffff;
  --c-gold:         #d4af37;
  --c-gold-light:   #f0d060;

  /* Typography */
  --ff-serif:     'Noto Serif JP', 'Cormorant Garamond', Georgia, serif;
  --ff-sans:      'Noto Sans JP', system-ui, sans-serif;
  --ff-display:   'Cormorant Garamond', 'Noto Serif JP', serif;

  /* Spacing */
  --space-xs:  0.25rem;
  --space-sm:  0.5rem;
  --space-md:  1rem;
  --space-lg:  1.5rem;
  --space-xl:  2rem;
  --space-2xl: 3rem;
  --space-3xl: 4.5rem;
  --space-4xl: 6rem;

  /* Layout */
  --max-w: 1280px;
  --radius: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;

  /* Transitions */
  --t-fast: 0.15s ease;
  --t-base: 0.3s ease;
  --t-slow: 0.5s ease;
}

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

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

body {
  font-family: var(--ff-sans);
  background: var(--c-bg);
  color: var(--c-text);
  line-height: 1.75;
  overflow-x: hidden;
}

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

a { text-decoration: none; color: inherit; }

button {
  cursor: pointer;
  border: none;
  background: none;
  font-family: inherit;
  color: inherit;
}

ul { list-style: none; }

/* ---------- Utilities ---------- */
.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

/* ===================================================
   HERO SECTION
   =================================================== */
.hero {
  position: relative;
  height: 100vh;
  min-height: 600px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: #000;
}

/* hero background: geometric pattern instead of remote image */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 20% 30%, rgba(212,175,55,0.12) 0%, transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(212,175,55,0.08) 0%, transparent 50%),
    repeating-linear-gradient(
      45deg,
      transparent,
      transparent 60px,
      rgba(212,175,55,0.03) 60px,
      rgba(212,175,55,0.03) 61px
    );
  opacity: 1;
}

.hero__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to bottom,
    rgba(0,0,0,0.3) 0%,
    rgba(0,0,0,0.65) 50%,
    rgba(0,0,0,0.9) 100%
  );
}

.hero__content {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: var(--space-xl);
  max-width: 820px;
}

.hero__eyebrow {
  font-family: var(--ff-sans);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--c-gold);
  margin-bottom: var(--space-lg);
  opacity: 0;
  animation: fadeInUp 0.8s 0.2s forwards;
}

.hero__title {
  font-family: var(--ff-display);
  font-size: clamp(2.8rem, 7vw, 5.5rem);
  font-weight: 400;
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--c-white);
  margin-bottom: var(--space-lg);
  opacity: 0;
  animation: fadeInUp 0.8s 0.4s forwards;
}

.hero__title span {
  color: var(--c-gold);
  font-style: italic;
}

.hero__subtitle {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: var(--c-text-light);
  margin-bottom: var(--space-2xl);
  line-height: 1.8;
  opacity: 0;
  animation: fadeInUp 0.8s 0.6s forwards;
}

.hero__cta {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-2xl);
  border: 1px solid var(--c-gold);
  color: var(--c-gold);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  transition: all var(--t-base);
  opacity: 0;
  animation: fadeInUp 0.8s 0.8s forwards;
}

.hero__cta:hover {
  background: var(--c-gold);
  color: #000;
}

.hero__cta i {
  animation: bounce 2s infinite;
}

.hero__scroll-indicator {
  position: absolute;
  bottom: var(--space-2xl);
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
}

.scroll-line {
  width: 1px;
  height: 60px;
  background: linear-gradient(to bottom, transparent, var(--c-gold));
  margin: 0 auto;
  animation: scrollPulse 2s infinite;
}

/* ===================================================
   INTRO SECTION
   =================================================== */
.intro {
  padding: var(--space-4xl) 0;
  border-bottom: 1px solid var(--c-border);
}

.intro__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4xl);
  align-items: center;
}

.section-title {
  font-family: var(--ff-serif);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 400;
  color: var(--c-white);
  margin-bottom: var(--space-lg);
  line-height: 1.3;
}

.intro__text p {
  color: var(--c-text-light);
  margin-bottom: var(--space-md);
  font-size: 1rem;
}

.intro__stats {
  display: flex;
  gap: var(--space-2xl);
  margin-top: var(--space-2xl);
  padding-top: var(--space-2xl);
  border-top: 1px solid var(--c-border);
}

.stat__number {
  display: block;
  font-family: var(--ff-display);
  font-size: 2.8rem;
  font-weight: 600;
  color: var(--c-gold);
  line-height: 1;
}

.stat__label {
  font-size: 0.8rem;
  color: var(--c-text-muted);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* Era Timeline */
.era-timeline {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  padding: var(--space-2xl);
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
}

.timeline-item {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-sm) 0;
  cursor: pointer;
  transition: color var(--t-fast);
  font-size: 0.95rem;
  color: var(--c-text-muted);
  border-bottom: 1px solid var(--c-border);
}

.timeline-item:last-child { border-bottom: none; }
.timeline-item:hover { color: var(--c-text); }

.timeline-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

/* ===================================================
   ERA NAVIGATION
   =================================================== */
.era-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(14,14,14,0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--c-border);
  padding: 0;
}

.era-nav__list {
  display: flex;
  overflow-x: auto;
  scrollbar-width: none;
}

.era-nav__list::-webkit-scrollbar { display: none; }

.era-nav__btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding: var(--space-md) var(--space-xl);
  position: relative;
  transition: all var(--t-base);
  white-space: nowrap;
  min-width: 120px;
  color: var(--c-text-muted);
  font-size: 0.85rem;
}

.era-nav__btn i {
  font-size: 1.1rem;
  margin-bottom: 4px;
  transition: color var(--t-base);
}

.era-nav__era-name {
  font-weight: 600;
  font-size: 0.78rem;
}

.era-nav__period {
  font-size: 0.65rem;
  color: var(--c-text-muted);
  opacity: 0;
  transition: opacity var(--t-base);
}

.era-nav__btn::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--era-color, var(--c-gold));
  transform: scaleX(0);
  transform-origin: center;
  transition: transform var(--t-base);
}

.era-nav__btn:hover,
.era-nav__btn.active {
  color: var(--c-white);
}

.era-nav__btn:hover i,
.era-nav__btn.active i {
  color: var(--era-color, var(--c-gold));
}

.era-nav__btn:hover .era-nav__period,
.era-nav__btn.active .era-nav__period {
  opacity: 1;
}

.era-nav__btn.active::after {
  transform: scaleX(1);
}

/* ===================================================
   ERA SECTIONS
   =================================================== */
.era-section {
  display: none;
  opacity: 0;
  transition: opacity var(--t-slow);
}

.era-section.active {
  display: block;
  animation: fadeIn 0.5s forwards;
}

/* Era Hero Banner */
.era-hero {
  position: relative;
  padding: var(--space-4xl) 0;
  overflow: hidden;
}

.era-hero__pattern {
  position: absolute;
  inset: 0;
  opacity: 0.06;
}

/* Egypt pattern */
.era-hero__pattern--egypt {
  background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23c4922a' fill-opacity='1'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

/* Greece pattern */
.era-hero__pattern--greece {
  background-image: url("data:image/svg+xml,%3Csvg width='44' height='12' viewBox='0 0 44 12' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M20 12v-2L0 0v10l2 2h18zM24 0l20 10v2H24V0z' fill='%234a90c4' fill-opacity='1' fill-rule='evenodd'/%3E%3C/svg%3E");
}

/* Medieval pattern */
.era-hero__pattern--medieval {
  background-image: url("data:image/svg+xml,%3Csvg width='40' height='40' viewBox='0 0 40 40' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='%237c5cbf' fill-opacity='1' fill-rule='evenodd'%3E%3Cpath d='M0 40L40 0H20L0 20M40 40V20L20 40'/%3E%3C/g%3E%3C/svg%3E");
}

/* Renaissance pattern */
.era-hero__pattern--renaissance {
  background-image: url("data:image/svg+xml,%3Csvg width='52' height='26' viewBox='0 0 52 26' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23b8860b' fill-opacity='1'%3E%3Cpath d='M10 10c0-2.21-1.79-4-4-4-3.314 0-6-2.686-6-6h2c0 2.21 1.79 4 4 4 3.314 0 6 2.686 6 6 0 2.21 1.79 4 4 4 3.314 0 6 2.686 6 6 0 2.21 1.79 4 4 4v2c-3.314 0-6-2.686-6-6 0-2.21-1.79-4-4-4-3.314 0-6-2.686-6-6zm25.464-1.95l8.486 8.486-1.414 1.414-8.486-8.486 1.414-1.414z' /%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

/* Baroque pattern */
.era-hero__pattern--baroque {
  background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23c0392b' fill-opacity='1'%3E%3Cpath d='M0 0l30 60L60 0H0zm30 4L56 56H4L30 4z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

/* Impressionism pattern */
.era-hero__pattern--impressionism {
  background-image: url("data:image/svg+xml,%3Csvg width='20' height='20' viewBox='0 0 20 20' xmlns='http://www.w3.org/2000/svg'%3E%3Ccircle cx='3' cy='3' r='3' fill='%232e8b57' fill-opacity='1'/%3E%3Ccircle cx='13' cy='13' r='3' fill='%232e8b57' fill-opacity='1'/%3E%3C/svg%3E");
}

.era-hero__content {
  position: relative;
  z-index: 2;
  text-align: center;
}

.era-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 64px;
  height: 64px;
  border-radius: 50%;
  font-size: 1.5rem;
  color: #fff;
  margin: 0 auto var(--space-lg);
  box-shadow: 0 0 30px currentColor;
}

.era-hero__period {
  font-size: 0.75rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.6);
  margin-bottom: var(--space-sm);
}

.era-hero__title {
  font-family: var(--ff-display);
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 400;
  color: var(--c-white);
  margin-bottom: var(--space-md);
  line-height: 1.15;
}

.era-hero__subtitle {
  font-size: 1.1rem;
  color: rgba(255,255,255,0.65);
  font-style: italic;
}

/* ===================================================
   ERA OVERVIEW
   =================================================== */
.era-overview {
  display: grid;
  grid-template-columns: 3fr 2fr;
  gap: var(--space-3xl);
  padding: var(--space-3xl) 0;
  border-bottom: 1px solid var(--c-border);
}

.era-overview__main h3 {
  font-family: var(--ff-serif);
  font-size: 1.4rem;
  font-weight: 500;
  color: var(--c-white);
  margin-bottom: var(--space-lg);
}

.era-overview__main p {
  color: var(--c-text-light);
  margin-bottom: var(--space-md);
  line-height: 1.85;
  font-size: 0.96rem;
}

.era-overview__features h4 {
  font-family: var(--ff-serif);
  font-size: 1rem;
  font-weight: 600;
  color: var(--c-white);
  margin-bottom: var(--space-md);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-size: 0.85rem;
}

.feature-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  margin-bottom: var(--space-2xl);
}

.feature-list li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  font-size: 0.9rem;
  color: var(--c-text-light);
  line-height: 1.5;
}

.feature-list i {
  color: var(--c-gold);
  margin-top: 3px;
  flex-shrink: 0;
  font-size: 0.8rem;
}

.era-importance {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-left: 3px solid var(--c-gold);
  padding: var(--space-lg);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.era-importance h4 {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
}

.era-importance h4 i {
  color: var(--c-gold);
}

.era-importance p {
  font-size: 0.88rem;
  color: var(--c-text-light);
  line-height: 1.7;
  margin: 0;
}

/* ===================================================
   ARTWORKS SECTION
   =================================================== */
.artworks-section {
  padding: var(--space-3xl) 0 var(--space-4xl);
}

.artworks-section__title {
  font-family: var(--ff-serif);
  font-size: 1.6rem;
  font-weight: 400;
  color: var(--c-white);
  margin-bottom: var(--space-2xl);
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.artworks-section__num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.2rem;
  height: 2.2rem;
  border: 1px solid var(--c-gold);
  color: var(--c-gold);
  font-family: var(--ff-display);
  font-size: 1.2rem;
  border-radius: 50%;
  flex-shrink: 0;
}

.artworks-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
}

/* ===================================================
   ARTWORK CARD
   =================================================== */
.artwork-card {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform var(--t-base), border-color var(--t-base), box-shadow var(--t-base);
}

.artwork-card:hover {
  transform: translateY(-4px);
  border-color: rgba(212, 175, 55, 0.3);
  box-shadow: 0 16px 40px rgba(0,0,0,0.5);
}

/* Card Header (replaces image area) */
.artwork-card__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-lg);
  background: linear-gradient(
    135deg,
    color-mix(in srgb, var(--era-color, var(--c-gold)) 15%, var(--c-surface-3)),
    var(--c-surface-3)
  );
  border-bottom: 2px solid var(--era-color, var(--c-gold));
  position: relative;
  overflow: hidden;
}

.artwork-card__header::before {
  content: '';
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    -45deg,
    transparent,
    transparent 8px,
    rgba(255,255,255,0.015) 8px,
    rgba(255,255,255,0.015) 9px
  );
}

.artwork-card__num-badge {
  font-family: var(--ff-display);
  font-size: 2rem;
  font-weight: 600;
  color: var(--era-color, var(--c-gold));
  line-height: 1;
  opacity: 0.9;
  position: relative;
  z-index: 1;
}

/* Card Body */
.artwork-card__body {
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  flex: 1;
}

.artwork-card__meta {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.artwork-card__period {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-text-muted);
  background: var(--c-surface-3);
  padding: 2px 8px;
  border-radius: 2px;
}

.artwork-card__date {
  font-size: 0.78rem;
  color: var(--c-text-muted);
}

.artwork-card__title {
  font-family: var(--ff-serif);
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--c-white);
  line-height: 1.4;
}

.artwork-card__medium {
  font-size: 0.8rem;
  color: var(--c-text-muted);
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.artwork-card__medium i {
  font-size: 0.7rem;
  color: var(--c-gold);
}

.artwork-card__desc {
  flex: 1;
}

.artwork-card__desc p {
  font-size: 0.875rem;
  color: var(--c-text-light);
  line-height: 1.8;
  margin-bottom: var(--space-sm);
}

.artwork-card__desc p:last-child { margin-bottom: 0; }

.artwork-card__desc strong {
  color: var(--c-white);
  font-weight: 600;
}

.artwork-card__keywords {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
  margin-top: var(--space-sm);
}

.artwork-card__keywords span {
  font-size: 0.7rem;
  padding: 2px 8px;
  border: 1px solid var(--c-border);
  border-radius: 100px;
  color: var(--c-text-muted);
}

.artwork-card__btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  margin-top: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--era-color, var(--c-gold));
  color: var(--era-color, var(--c-gold));
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  border-radius: var(--radius);
  transition: all var(--t-fast);
  align-self: flex-start;
}

.artwork-card__btn:hover {
  background: var(--era-color, var(--c-gold));
  color: #000;
}

/* ===================================================
   FOOTER
   =================================================== */
.site-footer {
  background: var(--c-surface);
  border-top: 1px solid var(--c-border);
  padding: var(--space-4xl) 0 var(--space-2xl);
  margin-top: var(--space-2xl);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-3xl);
  margin-bottom: var(--space-3xl);
}

.site-footer__brand h3 {
  font-family: var(--ff-serif);
  font-size: 1.2rem;
  color: var(--c-white);
  margin-bottom: var(--space-md);
}

.site-footer__brand p {
  font-size: 0.875rem;
  color: var(--c-text-muted);
  line-height: 1.75;
  margin-bottom: var(--space-md);
}

.footer-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 0.85rem;
  color: var(--c-gold);
  transition: opacity var(--t-fast);
}

.footer-link:hover { opacity: 0.7; }

.site-footer__eras h4,
.site-footer__info h4 {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--c-text-muted);
  margin-bottom: var(--space-md);
}

.site-footer__eras ul,
.site-footer__info ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.footer-era-btn {
  font-size: 0.875rem;
  color: var(--c-text-light);
  text-align: left;
  transition: color var(--t-fast);
  padding: 0;
}

.footer-era-btn:hover { color: var(--c-gold); }

.site-footer__info a {
  font-size: 0.875rem;
  color: var(--c-text-light);
  transition: color var(--t-fast);
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.site-footer__info a:hover { color: var(--c-gold); }
.site-footer__info a::before {
  content: '↗';
  font-size: 0.7rem;
  color: var(--c-text-muted);
}

.site-footer__bottom {
  border-top: 1px solid var(--c-border);
  padding-top: var(--space-xl);
  text-align: center;
}

.site-footer__bottom p {
  font-size: 0.78rem;
  color: var(--c-text-muted);
}

/* ===================================================
   BACK TO TOP
   =================================================== */
.back-to-top {
  position: fixed;
  bottom: var(--space-xl);
  right: var(--space-xl);
  width: 44px;
  height: 44px;
  background: var(--c-surface-2);
  border: 1px solid var(--c-border);
  color: var(--c-text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  font-size: 0.85rem;
  transition: all var(--t-base);
  opacity: 0;
  pointer-events: none;
  z-index: 200;
}

.back-to-top.visible {
  opacity: 1;
  pointer-events: auto;
}

.back-to-top:hover {
  background: var(--c-gold);
  border-color: var(--c-gold);
  color: #000;
  transform: translateY(-2px);
}

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

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50%       { transform: translateY(5px); }
}

@keyframes scrollPulse {
  0%   { transform: scaleY(0); transform-origin: top; opacity: 0; }
  50%  { transform: scaleY(1); transform-origin: top; opacity: 1; }
  100% { transform: scaleY(1); transform-origin: bottom; opacity: 0; }
}

/* (image placeholder styles removed) */

/* ===================================================
   RESPONSIVE — Tablet
   =================================================== */
@media (max-width: 1024px) {
  .container { padding: 0 var(--space-lg); }

  .intro__grid {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
  }

  .era-overview {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
  }

  .artworks-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .site-footer__grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-2xl);
  }

  .site-footer__brand {
    grid-column: 1 / -1;
  }
}

/* ===================================================
   RESPONSIVE — Mobile
   =================================================== */
@media (max-width: 640px) {
  .container { padding: 0 var(--space-md); }

  .hero__content { padding: var(--space-md); }

  .intro { padding: var(--space-2xl) 0; }

  .era-nav__btn {
    min-width: 90px;
    padding: var(--space-md) var(--space-md);
  }

  .era-nav__era-name { font-size: 0.7rem; }
  .era-nav__period { display: none; }

  .era-hero { padding: var(--space-2xl) 0; }

  .artworks-grid {
    grid-template-columns: 1fr;
    gap: var(--space-lg);
  }

  .artworks-section {
    padding: var(--space-2xl) 0 var(--space-3xl);
  }

  .intro__stats {
    gap: var(--space-xl);
  }

  .site-footer__grid {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
  }

  .back-to-top {
    bottom: var(--space-md);
    right: var(--space-md);
  }
}

/* ===================================================
   SELECTION COLOR
   =================================================== */
::selection {
  background: rgba(212,175,55,0.25);
  color: var(--c-white);
}

/* ===================================================
   SCROLLBAR
   =================================================== */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--c-bg); }
::-webkit-scrollbar-thumb {
  background: var(--c-border);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover { background: var(--c-text-muted); }