/* ============================================================
   meguro-sample.com — Archive Index Styles
   ============================================================ */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --c-bg:         #FFFFFF;
  --c-bg-soft:    #F7F6F4;
  --c-bg-muted:   #EFEDEA;
  --c-border:     #E4E2DE;
  --c-text:       #1A1714;
  --c-text-sub:   #6B6560;
  --c-text-inv:   #FFFFFF;
  --c-accent:     #C8953A;
  --c-accent-lt:  rgba(200, 149, 58, 0.10);

  --f-sans: 'DM Sans', 'Noto Sans JP', sans-serif;

  --max-w:   1200px;
  --pad-x:   1.25rem;
  --hdr-h:   60px;

  --ease:    cubic-bezier(0.16, 1, 0.3, 1);
  --t-fast:  180ms;
  --t-base:  280ms;
  --t-slow:  480ms;
}

@media (min-width: 768px) {
  :root { --pad-x: 2.5rem; --hdr-h: 68px; }
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--f-sans);
  background: var(--c-bg);
  color: var(--c-text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ── Layout helper ─────────────────────────────── */
.arc-container {
  max-width: var(--max-w);
  margin-inline: auto;
  padding-inline: var(--pad-x);
}

/* ══════════════════════════════════════════════
   HEADER
══════════════════════════════════════════════ */
.arc-header {
  position: sticky;
  top: 0;
  z-index: 200;
  height: var(--hdr-h);
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--c-border);
  transition: box-shadow var(--t-base) var(--ease);
}

.arc-header.is-scrolled {
  box-shadow: 0 2px 16px rgba(0,0,0,0.06);
}

.arc-header__inner {
  max-width: var(--max-w);
  margin-inline: auto;
  padding-inline: var(--pad-x);
  height: 100%;
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

/* Logo */
.arc-logo {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  flex-shrink: 0;
}

.arc-logo__img {
  height: 36px;
  width: auto;
  display: block;
}

.arc-logo--sm .arc-logo__img { height: 28px; }

/* 旧テキストロゴ要素（後方互換） */
.arc-logo__mark {
  font-size: 0.5rem;
  color: var(--c-accent);
  line-height: 1;
}

.arc-logo__text {
  font-family: var(--f-sans);
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--c-text);
}

.arc-logo--sm .arc-logo__text { font-size: 0.8125rem; }

.arc-logo__accent { color: var(--c-accent); }

.arc-logo__label {
  font-size: 0.6875rem;
  color: var(--c-text-sub);
  letter-spacing: 0.06em;
  padding-left: 0.75rem;
  margin-left: 0.75rem;
  border-left: 1px solid var(--c-border);
  white-space: nowrap;
}

/* ══════════════════════════════════════════════
   HERO
══════════════════════════════════════════════ */
.arc-hero {
  position: relative;
  overflow: hidden;
  padding-block: 5rem 4.5rem;
  background: var(--c-bg-soft);
  border-bottom: 1px solid var(--c-border);
}

.arc-hero__inner {
  max-width: var(--max-w);
  margin-inline: auto;
  padding-inline: var(--pad-x);
  position: relative;
  z-index: 1;
}

.arc-hero__eyebrow {
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.3em;
  color: var(--c-accent);
  text-transform: uppercase;
  margin-bottom: 1.25rem;
}

.arc-hero__title {
  font-size: clamp(1.875rem, 5vw, 2.75rem);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--c-text);
  margin-bottom: 1.5rem;
}

.arc-hero__lead {
  font-size: clamp(0.9375rem, 1.5vw, 1.0625rem);
  color: var(--c-text-sub);
  line-height: 1.8;
  max-width: 48ch;
  margin-bottom: 2rem;
}

.arc-hero__count {
  font-size: 0.8125rem;
  color: var(--c-text-sub);
  letter-spacing: 0.06em;
}

/* Decorative background pattern */
.arc-hero__deco {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(200,149,58,0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(200,149,58,0.06) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}

/* ══════════════════════════════════════════════
   FILTER BAR
══════════════════════════════════════════════ */
.arc-filter-bar {
  padding-block: 1.75rem 0;
}

.arc-filter {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  align-items: center;
}

.arc-filter__btn {
  font-family: var(--f-sans);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  padding: 0.375rem 1rem;
  border: 1px solid var(--c-border);
  border-radius: 100px;
  background: transparent;
  color: var(--c-text-sub);
  cursor: pointer;
  transition:
    background var(--t-fast) var(--ease),
    color var(--t-fast) var(--ease),
    border-color var(--t-fast) var(--ease);
}

.arc-filter__btn:hover {
  background: var(--c-bg-muted);
  color: var(--c-text);
}

.arc-filter__btn.is-active {
  background: var(--c-text);
  color: var(--c-text-inv);
  border-color: var(--c-text);
}

/* ══════════════════════════════════════════════
   MAIN / GRID
══════════════════════════════════════════════ */
.arc-main {
  padding-block: 2.5rem 6rem;
}

.arc-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  margin-top: 2rem;
}

@media (min-width: 640px) {
  .arc-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
  .arc-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 2.5rem;
  }
}

/* ══════════════════════════════════════════════
   CARD
══════════════════════════════════════════════ */
.arc-card {
  background: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: 14px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition:
    box-shadow var(--t-base) var(--ease),
    transform var(--t-base) var(--ease);
}

.arc-card:hover {
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.09);
  transform: translateY(-5px);
}

/* ── Preview ── */
.arc-card__preview {
  display: block;
  overflow: hidden;
  background: var(--c-bg-soft);
  position: relative;
  text-decoration: none;
  aspect-ratio: 3 / 4;
}

.arc-card__preview img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
  display: block;
  transition: transform var(--t-slow) var(--ease);
}

.arc-card:hover .arc-card__preview img {
  transform: scale(1.02);
}

.arc-card__preview--empty {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--c-bg-muted);
}

.arc-card__preview--empty::after {
  content: 'NO PREVIEW';
  font-size: 0.625rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  color: var(--c-border);
}

/* FV 自動取得ローディング中 */
.arc-card__preview--loading {
  min-height: 200px;
  background: var(--c-bg-muted);
  animation: thumbPulse 1.6s ease-in-out infinite;
}

@keyframes thumbPulse {
  0%, 100% { background: var(--c-bg-muted); }
  50%       { background: var(--c-bg-soft); }
}

/* Type badge */
.arc-card__badge {
  position: absolute;
  top: 0.875rem;
  left: 0.875rem;
  background: rgba(26, 23, 20, 0.68);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  color: #fff;
  font-size: 0.625rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  padding: 0.3125rem 0.6875rem;
  border-radius: 6px;
}

/* ── Body ── */
.arc-card__body {
  padding: 1.625rem 1.5rem 1.5rem;
  display: flex;
  flex-direction: column;
  flex: 1;
  gap: 0.625rem;
}

/* Meta: date + tags */
.arc-card__meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.arc-card__date {
  font-size: 0.6875rem;
  color: var(--c-text-sub);
  letter-spacing: 0.06em;
}

.arc-card__tags {
  display: flex;
  gap: 0.375rem;
  flex-wrap: wrap;
}

.arc-card__tag {
  font-size: 0.6875rem;
  font-weight: 500;
  color: var(--c-accent);
  background: var(--c-accent-lt);
  border-radius: 4px;
  padding: 0.2rem 0.5rem;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: background var(--t-fast) var(--ease);
}

.arc-card__tag:hover {
  background: rgba(200, 149, 58, 0.22);
}

/* Title + subtitle */
.arc-card__title {
  font-size: 1.0625rem;
  font-weight: 600;
  line-height: 1.3;
  color: var(--c-text);
  letter-spacing: 0.01em;
}

.arc-card__subtitle {
  font-size: 0.8125rem;
  color: var(--c-text-sub);
  margin-top: -0.25rem;
}

/* Concept / intent */
.arc-card__concept {
  font-size: 0.875rem;
  color: var(--c-text-sub);
  line-height: 1.8;
  flex: 1;
  display: -webkit-box;
  -webkit-line-clamp: 4;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* CTA */
.arc-card__cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--c-accent);
  text-decoration: none;
  letter-spacing: 0.06em;
  margin-top: 0.5rem;
  transition:
    gap var(--t-base) var(--ease),
    color var(--t-base) var(--ease);
}

.arc-card__cta:hover {
  gap: 0.875rem;
}

.arc-card__cta-icon {
  display: inline-block;
  transition: transform var(--t-base) var(--ease);
}

.arc-card__cta:hover .arc-card__cta-icon {
  transform: translateX(2px);
}

/* ── Fade-in reveal ── */
.arc-card {
  opacity: 0;
  transform: translateY(20px);
}

.arc-card.is-visible {
  animation: cardReveal var(--t-slow) var(--ease) both;
}

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

/* ══════════════════════════════════════════════
   PAGINATION
══════════════════════════════════════════════ */
.arc-pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding-top: 3rem;
}

.arc-page-nums {
  display: flex;
  gap: 0.375rem;
}

.arc-page-btn,
.arc-page-num {
  font-family: var(--f-sans);
  font-size: 0.8125rem;
  font-weight: 500;
  width: 2.5rem;
  height: 2.5rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--c-border);
  border-radius: 8px;
  background: transparent;
  color: var(--c-text-sub);
  cursor: pointer;
  transition:
    background var(--t-fast) var(--ease),
    color var(--t-fast) var(--ease),
    border-color var(--t-fast) var(--ease);
}

.arc-page-btn:hover:not(:disabled),
.arc-page-num:hover {
  background: var(--c-bg-muted);
  color: var(--c-text);
}

.arc-page-btn:disabled {
  opacity: 0.3;
  cursor: default;
}

.arc-page-num.is-active {
  background: var(--c-text);
  color: var(--c-text-inv);
  border-color: var(--c-text);
}

/* ══════════════════════════════════════════════
   LOADING / EMPTY / ERROR
══════════════════════════════════════════════ */
.arc-loading {
  grid-column: 1 / -1;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.5rem;
  padding: 6rem 1rem;
}

.arc-loading__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--c-border);
  animation: dotPulse 1.2s ease-in-out infinite both;
}

.arc-loading__dot:nth-child(2) { animation-delay: 0.2s; }
.arc-loading__dot:nth-child(3) { animation-delay: 0.4s; }

@keyframes dotPulse {
  0%, 80%, 100% { transform: scale(0.6); opacity: 0.4; }
  40%           { transform: scale(1);   opacity: 1;   }
}

.arc-empty {
  grid-column: 1 / -1;
  text-align: center;
  padding: 6rem 1rem;
  color: var(--c-text-sub);
  font-size: 0.9375rem;
}

.arc-error {
  grid-column: 1 / -1;
  text-align: center;
  padding: 6rem 1rem;
  color: #C0392B;
  font-size: 0.875rem;
}

/* ══════════════════════════════════════════════
   FOOTER
══════════════════════════════════════════════ */
.arc-footer {
  padding-block: 2.5rem;
  border-top: 1px solid var(--c-border);
  background: var(--c-bg-soft);
}

.arc-footer__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  text-align: center;
}

@media (min-width: 640px) {
  .arc-footer__inner {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}

.arc-footer__copy {
  font-size: 0.75rem;
  color: var(--c-text-sub);
  letter-spacing: 0.04em;
}

/* ══════════════════════════════════════════════
   REDUCED MOTION
══════════════════════════════════════════════ */
@media (prefers-reduced-motion: reduce) {
  .arc-card,
  .arc-card.is-visible {
    animation: none;
    opacity: 1;
    transform: none;
  }

  .arc-loading__dot {
    animation: none;
    opacity: 0.6;
    transform: scale(0.8);
  }
}