:root {
  --bg: #FFFFFF;
  --bg-page: #FAFBFC;
  --bg-card: #FFFFFF;
  --border: #E5E7EB;
  --border-light: #F3F4F6;
  --text: #1F2937;
  --text-secondary: #6B7280;
  --text-muted: #9CA3AF;
  --accent: #3B82F6;
  --accent-hover: #2563EB;
  --accent-light: #EFF6FF;
  --accent-gold: #D4AF37;
  --danger: #EF4444;
  --success: #10B981;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --font-serif: 'Noto Serif SC', 'Songti SC', Georgia, serif;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --transition: all 0.2s ease;
}

*, *::before, *::after { margin:0; padding:0; box-sizing:border-box; }
html { scroll-behavior: smooth; }
body { font-family: var(--font-sans); background: var(--bg-page); color: var(--text); min-height:100vh; line-height:1.6; font-size:15px; }

.navbar { position:fixed; top:0; left:0; right:0; z-index:100; background:var(--bg); border-bottom:1px solid var(--border-light); }
.nav-inner { max-width:1200px; margin:0 auto; padding:0 2rem; height:60px; display:flex; align-items:center; justify-content:space-between; }
.nav-logo { font-weight:700; font-size:1.15rem; color:var(--text); text-decoration:none; }
.nav-logo span { color:var(--accent); }
.nav-links { display:flex; align-items:center; gap:1.5rem; }
.nav-link { color:var(--text-secondary); text-decoration:none; font-size:0.9rem; font-weight:500; transition:var(--transition); }
.nav-link:hover { color:var(--text); }
.nav-link--user { color:var(--accent); }
.nav-cta { background:var(--accent); color:#fff; font-weight:600; font-size:0.85rem; padding:0.55rem 1.2rem; border-radius:var(--radius-md); text-decoration:none; transition:var(--transition); }
.nav-cta:hover { background:var(--accent-hover); }
.nav-user { display:flex; align-items:center; gap:0.3rem; margin-left:0.5rem; }

.main { max-width:1200px; margin:0 auto; padding:72px 2rem 4rem; }
.main--narrow { max-width:720px; }
.main--wide { max-width:900px; }

.page-hero { text-align:center; padding:3rem 0 2rem; }
.page-hero h1 { font-size:2rem; font-weight:700; color:var(--text); margin-bottom:0.75rem; }
.page-hero p { color:var(--text-secondary); font-size:1rem; max-width:500px; margin:0 auto; }

.card { background:var(--bg-card); border:1px solid var(--border-light); border-radius:var(--radius-lg); padding:1.5rem; transition:var(--transition); }
.card:hover { border-color:var(--border); box-shadow:0 1px 3px rgba(0,0,0,0.04); }
.card--clickable { cursor:pointer; }
.card__title { font-size:1.1rem; font-weight:600; color:var(--text); margin-bottom:0.5rem; }
.card__meta { color:var(--text-muted); font-size:0.8rem; margin-bottom:0.6rem; display:flex; gap:0.75rem; align-items:center; }
.card__meta .author { color:var(--accent); font-weight:500; }
.card__text { color:var(--text-secondary); font-size:0.9rem; line-height:1.6; }

.grid { display:grid; gap:1.25rem; }
.grid--2 { grid-template-columns:repeat(2,1fr); }
.grid--3 { grid-template-columns:repeat(3,1fr); }

.btn { display:inline-flex; align-items:center; justify-content:center; gap:0.4rem; padding:0.75rem 1.4rem; border-radius:var(--radius-md); font-weight:600; font-size:0.9rem; text-decoration:none; border:none; cursor:pointer; transition:var(--transition); font-family:inherit; }
.btn--primary { background:var(--accent); color:#fff; }
.btn--primary:hover { background:var(--accent-hover); }
.btn--secondary { background:transparent; color:var(--text); border:1px solid var(--border); }
.btn--secondary:hover { border-color:var(--accent); color:var(--accent); }
.btn--outline { background:transparent; color:var(--accent); border:1px solid var(--accent); }
.btn--outline:hover { background:var(--accent-light); }
.btn--small { padding:0.5rem 1rem; font-size:0.85rem; }
.btn--full { width:100%; }

.form-group { margin-bottom:1.25rem; }
.form-label { display:block; margin-bottom:0.4rem; font-size:0.85rem; font-weight:600; color:var(--text); }
.form-input, .form-textarea, .form-select { width:100%; padding:0.8rem 1rem; font-size:0.9rem; font-family:inherit; background:var(--bg); border:1px solid var(--border); border-radius:var(--radius-md); color:var(--text); transition:var(--transition); }
.form-input:focus, .form-textarea:focus, .form-select:focus { outline:none; border-color:var(--accent); box-shadow:0 0 0 3px var(--accent-light); }
.form-input::placeholder, .form-textarea::placeholder { color:var(--text-muted); }
.form-textarea { min-height:120px; resize:vertical; line-height:1.6; }
.form-hint { font-size:0.75rem; color:var(--text-muted); margin-top:0.35rem; }
.form-error { color:var(--danger); font-size:0.8rem; margin-top:0.35rem; }

.info-box { border-radius:var(--radius-md); padding:1rem; margin:1rem 0; font-size:0.85rem; line-height:1.6; }
.info-box--success { background:rgba(16,185,129,0.05); border:1px solid rgba(16,185,129,0.1); color:#059669; }
.info-box--warning { background:rgba(245,158,11,0.05); border:1px solid rgba(245,158,11,0.1); color:#d97706; }
.info-box--danger { background:rgba(239,68,68,0.05); border:1px solid rgba(239,68,68,0.1); color:#dc2626; }
.info-box--info { background:var(--accent-light); border:1px solid rgba(59,130,246,0.15); color:var(--accent); }

.flash { padding:0.9rem 1.1rem; border-radius:var(--radius-md); margin-bottom:1.25rem; font-size:0.85rem; font-weight:500; }
.flash--success { background:rgba(16,185,129,0.05); border:1px solid rgba(16,185,129,0.15); color:#059669; }
.flash--error { background:rgba(239,68,68,0.05); border:1px solid rgba(239,68,68,0.15); color:#dc2626; }

.badge { display:inline-flex; align-items:center; gap:0.25rem; font-size:0.7rem; font-weight:600; padding:0.2rem 0.6rem; border-radius:4px; }
.badge--primary { background:var(--accent-light); color:var(--accent); }
.badge--gold { background:rgba(212,175,55,0.1); color:#b8860b; }
.badge--green { background:rgba(16,185,129,0.08); color:#059669; }
.badge--red { background:rgba(239,68,68,0.08); color:#dc2626; }

.plaque { background:var(--bg-card); border:1px solid var(--border-light); border-radius:var(--radius-lg); padding:1.25rem; margin:1.5rem 0; }
.plaque__title { font-size:0.95rem; font-weight:600; color:var(--text); margin-bottom:0.75rem; }
.plaque__row { display:flex; justify-content:space-between; padding:0.4rem 0; border-bottom:1px solid var(--border-light); font-size:0.82rem; }
.plaque__row:last-child { border-bottom:none; }
.plaque__label { color:var(--text-muted); }
.plaque__value { color:var(--text); font-size:0.78rem; }

.footer { border-top:1px solid var(--border-light); margin-top:4rem; background:var(--bg); }
.footer-inner { max-width:1200px; margin:0 auto; padding:2.5rem 2rem; text-align:center; }
.footer-brand { color:var(--text-secondary); font-size:0.9rem; margin-bottom:0.75rem; }
.footer-links { display:flex; justify-content:center; gap:1.5rem; margin-bottom:0.75rem; }
.footer-links a { color:var(--text-muted); font-size:0.8rem; text-decoration:none; transition:var(--transition); }
.footer-links a:hover { color:var(--accent); }
.footer-contact { color:var(--text-muted); font-size:0.8rem; margin-bottom:0.75rem; }
.footer-contact a { color:var(--accent); text-decoration:none; }
.footer-copy { color:var(--text-muted); font-size:0.75rem; opacity:0.6; }

.empty-state { text-align:center; padding:4rem 2rem; }
.empty-state__icon { font-size:3rem; margin-bottom:1rem; opacity:0.3; }
.empty-state__title { font-size:1.25rem; font-weight:600; margin-bottom:0.4rem; }
.empty-state__text { color:var(--text-muted); font-size:0.9rem; }

.pagination { display:flex; justify-content:center; gap:0.3rem; padding:2rem 0; }
.pagination a, .pagination span { padding:0.45rem 0.85rem; border-radius:var(--radius-sm); font-size:0.85rem; font-weight:500; text-decoration:none; }
.pagination a { color:var(--text-secondary); }
.pagination a:hover { color:var(--accent); background:var(--accent-light); }
.pagination span { color:var(--text-muted); }
.pagination .current { background:var(--accent); color:#fff; }

.search-bar { display:flex; gap:0.5rem; max-width:500px; margin:0 auto 2rem; }
.search-bar input { flex:1; }

.tag { display:inline-block; padding:0.15rem 0.5rem; border-radius:4px; font-size:0.7rem; font-weight:500; background:var(--accent-light); color:var(--accent); margin-right:0.3rem; }

.divider { height:1px; background:var(--border-light); margin:1.5rem 0; }

@keyframes fadeIn { from { opacity:0; transform:translateY(8px); } to { opacity:1; transform:translateY(0); } }
.animate-fade-in { animation:fadeIn 0.3s ease-out; }

.table { width:100%; border-collapse:collapse; font-size:0.85rem; }
.table th { text-align:left; padding:0.75rem 0.9rem; color:var(--text-muted); font-weight:600; font-size:0.75rem; text-transform:uppercase; letter-spacing:0.05em; border-bottom:2px solid var(--border-light); }
.table td { padding:0.75rem 0.9rem; border-bottom:1px solid var(--border-light); color:var(--text-secondary); }
.table tr:hover td { background:var(--bg-page); }

.tool-grid { display:grid; grid-template-columns:repeat(auto-fill, minmax(240px,1fr)); gap:1.25rem; padding:1.5rem 0; }
.tool-card { background:var(--bg-card); border:1px solid var(--border-light); border-radius:var(--radius-lg); padding:1.5rem; text-align:center; text-decoration:none; color:inherit; display:block; transition:var(--transition); }
.tool-card:hover { border-color:var(--border); }
.tool-card__icon { font-size:2rem; margin-bottom:0.75rem; }
.tool-card__title { font-weight:600; font-size:0.95rem; margin-bottom:0.35rem; }
.tool-card__desc { color:var(--text-muted); font-size:0.8rem; line-height:1.5; }

.comment { padding:1rem 0; border-bottom:1px solid var(--border-light); }
.comment__header { display:flex; align-items:center; gap:0.6rem; margin-bottom:0.4rem; }
.comment__avatar { width:32px; height:32px; border-radius:50%; background:var(--accent); display:flex; align-items:center; justify-content:center; font-weight:600; font-size:0.75rem; color:#fff; }
.comment__meta { font-size:0.78rem; color:var(--text-muted); }
.comment__author { font-weight:600; color:var(--text); }
.comment__text { color:var(--text-secondary); font-size:0.9rem; line-height:1.6; padding-left:2.5rem; }

.stats-bar { display:grid; grid-template-columns:repeat(4,1fr); gap:1rem; margin-bottom:2rem; }
.stat-item { text-align:center; padding:1rem; background:var(--bg-card); border:1px solid var(--border-light); border-radius:var(--radius-lg); }
.stat-item__value { font-size:1.4rem; font-weight:700; color:var(--accent); }
.stat-item__label { font-size:0.75rem; color:var(--text-muted); margin-top:0.2rem; text-transform:uppercase; letter-spacing:0.05em; }

.admin-layout { display:grid; grid-template-columns:220px 1fr; min-height:100vh; }
.admin-sidebar { background:var(--bg); border-right:1px solid var(--border-light); padding:1.5rem 1rem; }
.admin-sidebar__logo { font-weight:700; font-size:1rem; color:var(--accent); margin-bottom:1.5rem; }
.admin-sidebar__nav { list-style:none; }
.admin-sidebar__nav li { margin-bottom:0.2rem; }
.admin-sidebar__nav a { display:block; padding:0.5rem 0.75rem; color:var(--text-secondary); text-decoration:none; border-radius:var(--radius-sm); font-size:0.85rem; transition:var(--transition); }
.admin-sidebar__nav a:hover, .admin-sidebar__nav a.active { background:var(--accent-light); color:var(--accent); }
.admin-main { padding:1.5rem; background:var(--bg-page); }
.admin-header { display:flex; justify-content:space-between; align-items:center; margin-bottom:1.5rem; }
.admin-header h1 { font-size:1.3rem; font-weight:600; }

.hero-home { text-align:center; padding:4rem 2rem 2.5rem; }
.hero-home__title { font-size:2.5rem; font-weight:700; color:var(--text); margin-bottom:0.8rem; line-height:1.3; }
.hero-home__title span { color:var(--accent); }
.hero-home__subtitle { color:var(--text-secondary); font-size:1rem; max-width:480px; margin:0 auto 2rem; line-height:1.6; }
.hero-home__actions { display:flex; gap:0.75rem; justify-content:center; }

.profile-header { display:flex; align-items:center; gap:1.25rem; margin-bottom:1.5rem; padding:1.5rem; background:var(--bg-card); border:1px solid var(--border-light); border-radius:var(--radius-lg); }
.profile-avatar { width:72px; height:72px; border-radius:50%; background:var(--accent); display:flex; align-items:center; justify-content:center; font-size:1.5rem; font-weight:700; color:#fff; }
.profile-info h2 { font-size:1.3rem; font-weight:600; margin-bottom:0.2rem; }
.profile-info p { color:var(--text-muted); font-size:0.85rem; }
.profile-tabs { display:flex; gap:0.3rem; border-bottom:1px solid var(--border-light); margin-bottom:1.25rem; }
.profile-tab { padding:0.6rem 1rem; color:var(--text-muted); text-decoration:none; font-size:0.85rem; font-weight:500; border-bottom:2px solid transparent; transition:var(--transition); }
.profile-tab:hover { color:var(--text); }
.profile-tab.active { color:var(--accent); border-bottom-color:var(--accent); }

.exhibition-hero { text-align:center; padding:3rem 2rem 1.5rem; }
.exhibition-hero h1 { font-size:1.8rem; font-weight:700; margin-bottom:0.6rem; }
.exhibition-hero p { color:var(--text-secondary); max-width:500px; margin:0 auto; font-size:0.95rem; }

.timestamp-cert { background:var(--bg-card); border:1px solid var(--border-light); border-radius:var(--radius-lg); padding:2rem; text-align:center; margin:1.5rem 0; }
.timestamp-cert__hash { font-size:0.7rem; color:var(--text-muted); word-break:break-all; margin:0.75rem 0; padding:0.75rem; background:var(--bg-page); border-radius:var(--radius-md); }

.license-page { max-width:800px; }
.license-page h2 { color:var(--accent); font-size:1.15rem; font-weight:600; margin:1.5rem 0 0.75rem; padding-bottom:0.4rem; border-bottom:1px solid var(--border-light); }
.license-page p { color:var(--text-secondary); margin-bottom:0.75rem; line-height:1.7; font-size:0.9rem; }
.license-page ol { margin-left:1.25rem; color:var(--text-secondary); }
.license-page ol li { margin-bottom:0.5rem; line-height:1.6; font-size:0.9rem; }

@media (max-width: 900px) {
  .grid--2, .grid--3 { grid-template-columns:1fr; }
  .nav-inner { padding:0 1rem; }
  .nav-links .nav-link:not(.nav-cta):not(.nav-link--user) { display:none; }
  .main { padding:68px 1rem 3rem; }
  .page-hero h1 { font-size:1.5rem; }
  .search-bar { flex-direction:column; }
}
@media (max-width: 768px) {
  .hero-home__title { font-size:1.8rem; }
  .stats-bar { grid-template-columns:repeat(2,1fr); }
  .admin-layout { grid-template-columns:1fr; }
  .admin-sidebar { display:none; }
  .profile-header { flex-direction:column; text-align:center; }
}

::-webkit-scrollbar { width:6px; }
::-webkit-scrollbar-track { background:transparent; }
::-webkit-scrollbar-thumb { background:#D1D5DB; border-radius:3px; }
::-webkit-scrollbar-thumb:hover { background:#9CA3AF; }