/* ═══════════════════════════════════════════════════════════
   艺术部落 — 前台主题
   主色：#9E6B4B (赭石/ochre) · 深色导航 #1C1A17
   ═══════════════════════════════════════════════════════════ */

:root {
  --na-primary: #9E6B4B;
  --na-primary-dark: #7E5538;
  --na-primary-light: #B8845F;
  --na-primary-soft: rgba(158, 107, 75, 0.1);
  --na-dark: #1C1A17;
  --na-dark-2: #2A2723;
  --na-cream: #F8F5F0;
  --na-cream-2: #F0EBE3;
  --na-text: #2D2A26;
  --na-text-muted: #8B8580;
  --na-border: #E5DFD6;
  --na-shadow: 0 4px 24px rgba(0,0,0,0.08);
  --na-shadow-hover: 0 8px 40px rgba(0,0,0,0.14);
  --navbar-h: 64px;
  --font-serif: "Noto Serif SC", "Songti SC", serif;
  --font-sans: "Noto Sans SC", -apple-system, "Segoe UI", sans-serif;
}

/* ── 基础 ── */
body {
  font-family: var(--font-sans);
  color: var(--na-text);
  background-color: var(--na-cream);
}
h1,h2,h3,h4,h5,h6 { font-family: var(--font-serif); }

::selection { background: var(--na-primary); color: #fff; }

a { color: var(--na-primary); text-decoration: none; transition: color .15s; }
a:hover { color: var(--na-primary-dark); }

/* ── 滚动条美化 ── */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--na-cream-2); }
::-webkit-scrollbar-thumb { background: var(--na-border); border-radius: 5px; }
::-webkit-scrollbar-thumb:hover { background: var(--na-primary-light); }

/* ═══════════════ 导航栏 ═══════════════ */
.site-navbar {
  background: var(--na-dark);
  height: var(--navbar-h);
  box-shadow: 0 2px 12px rgba(0,0,0,0.15);
  transition: background .2s;
}

.navbar-brand {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.35rem;
  color: #fff !important;
}
.brand-logo { font-size: 1.4rem; }
.brand-sub {
  font-family: var(--font-sans);
  font-size: 0.7rem;
  font-weight: 400;
  color: var(--na-primary-light);
  margin-left: 3px;
  vertical-align: middle;
}

.site-navbar .nav-link {
  color: rgba(255,255,255,0.75) !important;
  font-size: 0.92rem;
  font-weight: 500;
  padding: 0.5rem 1rem !important;
  border-radius: 0.375rem;
  transition: all .15s;
}
.site-navbar .nav-link:hover,
.site-navbar .nav-link.active {
  color: #fff !important;
  background: rgba(255,255,255,0.08);
}
.site-navbar .nav-link.active {
  color: var(--na-primary-light) !important;
}

#navSearchToggle {
  background: transparent;
  border: none;
}
#navSearchToggle:hover { color: #fff; }

/* ── 展开式搜索 ── */
.nav-search-bar {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--na-dark-2);
  padding: 1rem 0;
  max-height: 0;
  overflow: hidden;
  transition: max-height .25s ease;
  border-top: 1px solid rgba(255,255,255,0.06);
}
.nav-search-bar.open { max-height: 100px; padding: 1rem 0; }
.nav-search-bar .form-control {
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.12);
  color: #fff;
}
.nav-search-bar .form-control::placeholder { color: rgba(255,255,255,0.4); }
.nav-search-bar .form-control:focus {
  background: rgba(255,255,255,0.1);
  border-color: var(--na-primary);
  box-shadow: 0 0 0 .2rem rgba(158,107,75,0.25);
}

/* ── 用户区域 ── */
.nav-avatar {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--na-primary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 0.85rem;
  font-weight: 700;
  cursor: pointer;
}

/* ── Offcanvas 移动菜单 ── */
.offcanvas-dark {
  background: var(--na-dark);
  color: #fff;
}
.offcanvas-dark .offcanvas-title { color: #fff; font-family: var(--font-serif); }

/* ═══════════════ Bootstrap 主色覆盖 ═══════════════ */
.btn-primary {
  --bs-btn-bg: var(--na-primary);
  --bs-btn-border-color: var(--na-primary);
  --bs-btn-hover-bg: var(--na-primary-dark);
  --bs-btn-hover-border-color: var(--na-primary-dark);
  --bs-btn-active-bg: var(--na-primary-dark);
  --bs-btn-active-border-color: var(--na-primary-dark);
}
.btn-outline-primary {
  --bs-btn-color: var(--na-primary);
  --bs-btn-border-color: var(--na-primary);
  --bs-btn-hover-bg: var(--na-primary);
  --bs-btn-hover-border-color: var(--na-primary);
  --bs-btn-active-bg: var(--na-primary);
}
.btn-outline-light {
  --bs-btn-color: rgba(255,255,255,0.7);
  --bs-btn-border-color: rgba(255,255,255,0.2);
  --bs-btn-hover-bg: rgba(255,255,255,0.1);
  --bs-btn-hover-border-color: rgba(255,255,255,0.3);
  --bs-btn-hover-color: #fff;
}
.btn-outline-dark {
  --bs-btn-color: var(--na-dark);
  --bs-btn-border-color: var(--na-border);
  --bs-btn-hover-bg: var(--na-dark);
  --bs-btn-hover-border-color: var(--na-dark);
  --bs-btn-hover-color: #fff;
}
.text-primary { color: var(--na-primary) !important; }
.bg-primary { background-color: var(--na-primary) !important; }
.form-control:focus,
.form-select:focus {
  border-color: var(--na-primary-light);
  box-shadow: 0 0 0 .2rem rgba(158,107,75,0.15);
}
.form-check-input:checked {
  background-color: var(--na-primary);
  border-color: var(--na-primary);
}
.badge.bg-primary-soft {
  background: var(--na-primary-soft);
  color: var(--na-primary);
}
.badge.bg-success-soft {
  background: rgba(45, 125, 70, 0.12);
  color: #2D7D46;
}
a.card-link { color: inherit; }
a.card-link:hover { color: inherit; }

/* ═══════════════ 通用工具类 ═══════════════ */
.text-muted { color: var(--na-text-muted) !important; }
.section-title {
  font-family: var(--font-serif);
  font-weight: 700;
  position: relative;
}
.section-title::after {
  content: "";
  display: block;
  width: 48px;
  height: 3px;
  background: var(--na-primary);
  margin-top: 0.5rem;
  border-radius: 2px;
}
.section-title.center::after { margin: 0.5rem auto 0; }

/* ═══════════════ 首页 Hero ═══════════════ */
.hero-section {
  position: relative;
  min-height: 78vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: var(--na-dark);
}
.hero-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0.45;
  filter: grayscale(20%) contrast(1.05);
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(28,26,23,0.85) 0%, rgba(28,26,23,0.3) 100%);
}
.hero-content {
  position: relative;
  z-index: 2;
  color: #fff;
}
.hero-content h1 {
  font-size: clamp(2.2rem, 5vw, 4rem);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: 0.02em;
}
.hero-content p.lead {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: rgba(255,255,255,0.85);
  max-width: 600px;
}
.hero-stats {
  display: flex;
  gap: 2.5rem;
  flex-wrap: wrap;
  margin-top: 2rem;
}
.hero-stat .num {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 700;
  color: var(--na-primary-light);
}
.hero-stat .label {
  font-size: 0.85rem;
  color: rgba(255,255,255,0.6);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* ═══════════════ 筛选标签栏 ═══════════════ */
.filter-bar {
  background: #fff;
  padding: 1rem;
  border-radius: 0.5rem;
  box-shadow: var(--na-shadow);
  margin-bottom: 2rem;
}
.tag-pills {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}
.tag-pill {
  padding: 0.375rem 0.9rem;
  border-radius: 2rem;
  background: var(--na-cream-2);
  color: var(--na-text-muted);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all .15s;
  white-space: nowrap;
}
.tag-pill:hover {
  background: var(--na-primary-soft);
  color: var(--na-primary);
}
.tag-pill.active {
  background: var(--na-primary);
  color: #fff;
}

/* ═══════════════ 瀑布流画廊 ═══════════════ */
.masonry {
  column-count: 1;
  column-gap: 1.25rem;
}
@media (min-width: 576px) { .masonry { column-count: 2; } }
@media (min-width: 768px) { .masonry { column-count: 3; } }
@media (min-width: 1200px) { .masonry { column-count: 4; } }

.masonry-item {
  break-inside: avoid;
  margin-bottom: 1.25rem;
}

.art-card {
  position: relative;
  overflow: hidden;
  border-radius: 0.5rem;
  background: #fff;
  box-shadow: var(--na-shadow);
  transition: box-shadow .25s, transform .25s;
  cursor: pointer;
  display: block;
  text-decoration: none;
}
.art-card:hover {
  box-shadow: var(--na-shadow-hover);
  transform: translateY(-4px);
}
.art-card img {
  width: 100%;
  height: auto;
  display: block;
  transition: transform .5s ease;
}
.art-card:hover img { transform: scale(1.04); }
.art-card .art-overlay {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  padding: 1.25rem 1rem 0.9rem;
  background: linear-gradient(transparent, rgba(0,0,0,0.82));
  color: #fff;
  opacity: 0;
  transform: translateY(10px);
  transition: opacity .25s, transform .25s;
}
.art-card:hover .art-overlay {
  opacity: 1;
  transform: translateY(0);
}
.art-card .art-title {
  font-family: var(--font-serif);
  font-size: 0.95rem;
  font-weight: 600;
  margin: 0 0 2px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.art-card .art-artist {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.7);
}
.art-card .fav-btn {
  position: absolute;
  top: 0.7rem;
  right: 0.7rem;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(4px);
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--na-text-muted);
  font-size: 0.95rem;
  opacity: 0;
  transition: all .2s;
  z-index: 3;
}
.art-card:hover .fav-btn { opacity: 1; }
.art-card .fav-btn:hover { background: #fff; color: var(--na-primary); }
.art-card .fav-btn.favorited { opacity: 1; color: #e74c3c; background: #fff; }

/* ── 骨架屏 ── */
.skeleton-card {
  border-radius: 0.5rem;
  overflow: hidden;
  background: #fff;
  box-shadow: var(--na-shadow);
}
.skeleton-img {
  width: 100%;
  aspect-ratio: 3/4;
  background: linear-gradient(90deg, #efe9df 25%, #f6f2ea 50%, #efe9df 75%);
  background-size: 200% 100%;
  animation: shimmer 1.4s infinite;
}
@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* ═══════════════ 加载更多 / 空状态 ═══════════════ */
.load-more-wrap { text-align: center; padding: 2rem 0 1rem; }
.empty-state {
  text-align: center;
  padding: 4rem 1rem;
  color: var(--na-text-muted);
}
.empty-state i { font-size: 3.5rem; opacity: 0.25; margin-bottom: 1rem; }

/* ═══════════════ 作品详情页 ═══════════════ */
.detail-hero {
  background: var(--na-dark);
  padding: 2.5rem 0;
}
.detail-img-wrap {
  background: #fff;
  border-radius: 0.5rem;
  overflow: hidden;
  box-shadow: var(--na-shadow-hover);
}
.detail-img-wrap img { width: 100%; height: auto; display: block; }
.detail-info h1 {
  font-family: var(--font-serif);
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 700;
  color: #fff;
}
.detail-info .artist-name {
  font-size: 1.1rem;
  color: var(--na-primary-light);
  margin-bottom: 1.5rem;
}
.detail-meta {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.6rem 1rem;
  font-size: 0.9rem;
}
.detail-meta dt {
  color: rgba(255,255,255,0.45);
  font-weight: 500;
  white-space: nowrap;
}
.detail-meta dd {
  color: rgba(255,255,255,0.9);
  margin: 0;
}
.detail-tags {
  display: flex;
  gap: 0.4rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}
.detail-tags .tag-pill {
  background: rgba(255,255,255,0.08);
  color: rgba(255,255,255,0.8);
}

.detail-description {
  background: #fff;
  border-radius: 0.5rem;
  padding: 2rem;
  box-shadow: var(--na-shadow);
  margin: 2rem 0;
}
.detail-description h3 {
  font-size: 1.3rem;
  margin-bottom: 1rem;
}

/* ═══════════════ 登录页 ═══════════════ */
.login-section {
  min-height: calc(100vh - var(--navbar-h));
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, var(--na-dark) 0%, var(--na-dark-2) 100%);
  position: relative;
  overflow: hidden;
}
.login-section::before {
  content: "";
  position: absolute;
  inset: 0;
  background: url("https://images.metmuseum.org/CRDImages/Original/original_621.jpg") center/cover;
  opacity: 0.12;
  filter: grayscale(40%);
}
.login-card {
  position: relative;
  z-index: 2;
  background: #fff;
  border-radius: 1rem;
  box-shadow: 0 1rem 3rem rgba(0,0,0,0.3);
  overflow: hidden;
}
.login-card-side {
  background: var(--na-primary);
  color: #fff;
  padding: 2.5rem;
}
.login-card-form { padding: 2.5rem; }

/* ═══════════════ 收藏页 ═══════════════ */
.fav-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1.25rem;
}

/* ═══════════════ 关于页 ═══════════════ */
.about-section { padding: 3rem 0; }
.about-hero {
  background: var(--na-dark);
  color: #fff;
  padding: 4rem 0;
  text-align: center;
}
.about-hero h1 { font-size: clamp(2rem, 4vw, 3rem); }
.feature-card {
  background: #fff;
  border-radius: 0.5rem;
  box-shadow: var(--na-shadow);
  padding: 2rem;
  text-align: center;
  height: 100%;
  transition: transform .2s;
}
.feature-card:hover { transform: translateY(-4px); }
.feature-card i {
  font-size: 2.5rem;
  color: var(--na-primary);
  margin-bottom: 1rem;
}

/* ═══════════════ 页脚 ═══════════════ */
.site-footer {
  background: var(--na-dark);
  margin-top: auto;
}
.site-footer a { color: rgba(255,255,255,0.65); }
.site-footer a:hover { color: #fff; }
.footer-brand { font-family: var(--font-serif); color: #fff; }
.footer-links li { margin-bottom: 0.5rem; }

/* ═══════════════ Toast 提示 ═══════════════ */
.na-toast-container {
  position: fixed;
  top: 80px;
  right: 1rem;
  z-index: 9999;
  min-width: 280px;
  max-width: 380px;
}
.na-toast {
  background: #fff;
  border-radius: 0.5rem;
  box-shadow: 0 4px 24px rgba(0,0,0,0.15);
  padding: 0.85rem 1rem;
  margin-bottom: 0.5rem;
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  animation: toastSlide .3s ease;
  border-left: 4px solid var(--na-primary);
}
.na-toast.success { border-left-color: #2D7D46; }
.na-toast.error { border-left-color: #D94E4E; }
.na-toast.warning { border-left-color: #E8A838; }
.na-toast .icon { flex-shrink: 0; font-size: 1.1rem; }
.na-toast.success .icon { color: #2D7D46; }
.na-toast.error .icon { color: #D94E4E; }
.na-toast.warning .icon { color: #E8A838; }
.na-toast .msg { font-size: 0.9rem; color: var(--na-text); }
@keyframes toastSlide {
  from { transform: translateX(120%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}
.na-toast.hiding { animation: toastOut .3s ease forwards; }
@keyframes toastOut {
  to { transform: translateX(120%); opacity: 0; }
}

/* ═══════════════ 响应式微调 ═══════════════ */
@media (max-width: 575.98px) {
  .hero-section { min-height: 60vh; }
  .hero-stats { gap: 1.5rem; }
  .detail-description { padding: 1.25rem; }
  .login-card-side, .login-card-form { padding: 1.5rem; }
}
@media (max-width: 991.98px) {
  .detail-info { margin-top: 1.5rem; }
}

/* ── 图片加载淡入 ── */
.fade-in-img {
  opacity: 0;
  transition: opacity .4s ease;
}
.fade-in-img.loaded { opacity: 1; }

/* ── 旋转加载图标 ── */
.spinner-border-sm { width: 1rem; height: 1rem; border-width: 0.15em; }