:root {
  --bg: #12141a;
  --bg-elevated: #1c1f28;
  --bg-card: #20232e;
  --border: #33384a;
  --text: #ecedf2;
  --text-dim: #9ba0b3;
  --accent: #c9a24a;
  --accent-soft: #3a3220;
  --danger: #d96c6c;
  --success: #6fbf73;
  --radius: 12px;
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", sans-serif;
  -webkit-tap-highlight-color: transparent;
  overscroll-behavior-y: none;
}

body {
  padding-top: var(--safe-top);
  padding-bottom: var(--safe-bottom);
}

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

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

.app-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(18, 20, 26, 0.92);
  backdrop-filter: blur(10px);
  padding: calc(10px + var(--safe-top)) 16px 0 16px;
  margin-top: calc(-1 * var(--safe-top));
  border-bottom: 1px solid var(--border);
}

.app-title {
  margin: 0 0 8px 0;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--accent);
}

.tab-nav {
  display: flex;
  gap: 4px;
}

.tab-btn {
  flex: 1;
  padding: 10px 8px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-dim);
  border-bottom: 2px solid transparent;
}

.tab-btn.is-active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

#main {
  max-width: 900px;
  margin: 0 auto;
  padding: 16px;
  padding-bottom: calc(32px + var(--safe-bottom));
}

.view { display: none; }
.view.is-active { display: block; }

/* ===== ギャラリー ===== */

.gallery-controls {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 12px;
}

.search-input,
.filter-select {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 10px 12px;
  border-radius: var(--radius);
  font-size: 15px;
  min-width: 0;
}

.filter-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.filter-select { flex: 1 1 30%; min-width: 100px; }

.result-count {
  color: var(--text-dim);
  font-size: 13px;
  margin: 0 0 10px 2px;
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 12px;
}

.painting-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  text-align: left;
  display: flex;
  flex-direction: column;
}

.painting-card-image-wrap {
  aspect-ratio: 4 / 5;
  background: #0c0d11;
  overflow: hidden;
}

.painting-card-image-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.painting-card-body {
  padding: 8px 10px 10px;
}

.painting-card-title {
  font-size: 13px;
  font-weight: 600;
  line-height: 1.3;
  margin: 0 0 2px;
}

.painting-card-artist {
  font-size: 11px;
  color: var(--text-dim);
  margin: 0;
}

.painting-card-badge {
  display: inline-block;
  margin-top: 6px;
  font-size: 10px;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 2px 6px;
  border-radius: 6px;
}

.empty-state {
  text-align: center;
  color: var(--text-dim);
  padding: 40px 0;
  grid-column: 1 / -1;
}

/* ===== 詳細画面 ===== */

.detail-topbar {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}

.icon-btn {
  font-size: 20px;
  padding: 8px 12px;
  color: var(--text);
  background: var(--bg-elevated);
  border-radius: 8px;
}

#detail-next { margin-left: auto; }

.detail-image-wrap {
  width: 100%;
  aspect-ratio: 1 / 1;
  background: #0c0d11;
  border-radius: var(--radius);
  overflow: hidden;
  touch-action: none;
  position: relative;
}

.detail-image {
  width: 100%;
  height: 100%;
  object-fit: contain;
  transform-origin: 0 0;
  will-change: transform;
}

.detail-body { padding-top: 16px; }

.detail-title {
  margin: 0 0 2px;
  font-size: 20px;
}

.detail-title-original {
  margin: 0 0 8px;
  font-style: italic;
  color: var(--text-dim);
  font-size: 13px;
}

.detail-meta {
  color: var(--text-dim);
  font-size: 13px;
  line-height: 1.6;
  margin: 0 0 16px;
}

.detail-affiliate {
  font-size: 13px;
  margin: -8px 0 16px;
}

.detail-affiliate a {
  color: var(--accent);
  text-decoration: none;
}

.app-footer {
  text-align: center;
  font-size: 12px;
  color: var(--text-dim);
  padding: 16px calc(16px + var(--safe-bottom, 0px)) calc(24px + var(--safe-bottom, 0px));
  border-top: 1px solid var(--border);
}

.footer-links {
  margin: 0 0 6px;
}

.footer-links a {
  color: var(--text-dim);
}

.footer-donate {
  margin: 6px 0 0;
}

.footer-donate a {
  color: var(--accent);
  text-decoration: none;
}

.pr-label {
  display: inline-block;
  font-size: 10px;
  font-weight: 700;
  color: var(--accent);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  padding: 1px 5px;
  border-radius: 4px;
  margin-left: 5px;
  vertical-align: middle;
}

/* 単独ページ(about / privacy) */
.page-body {
  margin: 0;
}

.page-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  background: rgba(18, 20, 26, 0.92);
  backdrop-filter: blur(10px);
  padding: calc(10px + var(--safe-top)) 16px calc(10px + var(--safe-top)) 16px;
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.page-header .brand {
  color: var(--accent);
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.02em;
}

.page-header .main-nav a {
  color: var(--text-dim);
  font-size: 13px;
}

.page-main {
  max-width: 720px;
  margin: 0 auto;
  padding: 24px 16px calc(48px + var(--safe-bottom));
}

.page-title {
  font-size: 20px;
  margin: 0 0 6px;
}

.page-lead {
  color: var(--text-dim);
  margin: 0 0 20px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  margin-bottom: 8px;
}

.card p {
  margin: 6px 0;
}

.page-footer {
  text-align: center;
  font-size: 12px;
  color: var(--text-dim);
  padding: 16px calc(16px + var(--safe-bottom, 0px)) calc(24px + var(--safe-bottom, 0px));
  border-top: 1px solid var(--border);
}

.tab-strip {
  display: flex;
  overflow-x: auto;
  gap: 4px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 12px;
  scrollbar-width: none;
}
.tab-strip::-webkit-scrollbar { display: none; }

.detail-tab-btn {
  flex: 0 0 auto;
  padding: 8px 12px;
  font-size: 13px;
  color: var(--text-dim);
  white-space: nowrap;
  border-bottom: 2px solid transparent;
}

.detail-tab-btn.is-active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.detail-tab-content {
  font-size: 15px;
  line-height: 1.8;
  color: var(--text);
}

.detail-tab-content ul {
  margin: 0;
  padding-left: 20px;
}

.detail-tab-content li { margin-bottom: 6px; }

/* ===== 学習モード ===== */

.timeline-intro, .quiz-intro {
  text-align: center;
  padding: 40px 16px;
}

.primary-btn {
  background: var(--accent);
  color: #1a1608;
  font-weight: 700;
  padding: 12px 24px;
  border-radius: 999px;
  font-size: 15px;
  margin-top: 12px;
}

.secondary-btn {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 12px 24px;
  border-radius: 999px;
  font-size: 15px;
  margin-top: 8px;
}

.timeline-progress {
  height: 4px;
  background: var(--bg-elevated);
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: 16px;
}

.timeline-progress-bar {
  height: 100%;
  background: var(--accent);
  width: 0%;
  transition: width 0.2s;
}

.timeline-card {
  min-height: 300px;
}

.movement-card {
  background: var(--bg-card);
  border: 1px solid var(--accent);
  border-radius: var(--radius);
  padding: 24px 16px;
  text-align: center;
}

.movement-card h3 {
  color: var(--accent);
  margin: 0 0 8px;
  font-size: 20px;
}

.movement-card p {
  line-height: 1.8;
  color: var(--text);
}

.timeline-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 16px;
}

.timeline-position {
  color: var(--text-dim);
  font-size: 13px;
}

/* ===== クイズ ===== */

.quiz-stats {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin: 16px 0;
  color: var(--text-dim);
  font-size: 13px;
}

.quiz-stats strong {
  display: block;
  color: var(--text);
  font-size: 20px;
}

.quiz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.quiz-progress-label {
  color: var(--text-dim);
  font-size: 13px;
}

.quiz-question {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 16px;
}

.quiz-question img {
  width: 100%;
  max-height: 320px;
  object-fit: contain;
  border-radius: 8px;
  margin-bottom: 12px;
  background: #0c0d11;
}

.quiz-question-text {
  font-size: 16px;
  line-height: 1.6;
}

.quiz-choices {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.quiz-choice-btn {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px;
  text-align: left;
  font-size: 15px;
}

.quiz-choice-btn.is-correct {
  border-color: var(--success);
  background: rgba(111, 191, 115, 0.15);
}

.quiz-choice-btn.is-wrong {
  border-color: var(--danger);
  background: rgba(217, 108, 108, 0.15);
}

.quiz-choice-btn:disabled { opacity: 0.7; }

.quiz-feedback {
  margin-top: 12px;
  padding: 12px;
  border-radius: var(--radius);
  background: var(--bg-elevated);
  font-size: 14px;
  line-height: 1.6;
}

#quiz-next { width: 100%; margin-top: 16px; }

.quiz-result {
  text-align: center;
  padding: 40px 16px;
}

.quiz-result .result-score {
  font-size: 40px;
  color: var(--accent);
  font-weight: 700;
  margin: 16px 0;
}

/* ===== レスポンシブ (iPhone最小幅対応) ===== */

@media (max-width: 400px) {
  .gallery-grid {
    grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  }
  .app-title { font-size: 16px; }
  .filter-select { flex: 1 1 100%; }
}

/* ライトモード対応(将来の切り替え用。デフォルトはダーク) */
@media (prefers-color-scheme: light) {
  :root {
    --bg: #12141a;
    --bg-elevated: #1c1f28;
    --bg-card: #20232e;
    --text: #ecedf2;
  }
}