:root {
  color-scheme: light;
  --bg: #f6f7fb;
  --surface: #ffffff;
  --surface-soft: #eef4f8;
  --ink: #172033;
  --muted: #667085;
  --line: #d9e2ea;
  --blue: #2563eb;
  --teal: #0f766e;
  --rose: #b4235b;
  --amber: #b7791f;
  --shadow: 0 18px 48px rgba(23, 32, 51, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  background:
    linear-gradient(135deg, rgba(37, 99, 235, 0.08), transparent 34%),
    linear-gradient(45deg, rgba(15, 118, 110, 0.08), transparent 42%),
    var(--bg);
  color: var(--ink);
  font-family:
    Inter, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, sans-serif;
  line-height: 1.6;
}

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

button,
input {
  font: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid rgba(217, 226, 234, 0.86);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(16px);
}

.header-inner {
  max-width: 1440px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.brand-logo {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  box-shadow: 0 8px 18px rgba(37, 99, 235, 0.16);
}

.brand-copy {
  display: grid;
  gap: 0;
}

.brand-copy strong {
  font-size: 20px;
  letter-spacing: 0;
}

.brand-copy small {
  color: var(--muted);
  font-size: 12px;
}

.top-nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.top-nav a {
  min-height: 40px;
  padding: 8px 14px;
  border: 1px solid transparent;
  border-radius: 8px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
}

.top-nav a:hover {
  border-color: var(--line);
  color: var(--ink);
  background: var(--surface-soft);
}

main {
  max-width: 1440px;
  margin: 0 auto;
  padding: 34px 24px 42px;
}

.intro {
  min-height: 260px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 360px);
  align-items: end;
  gap: 28px;
  padding: 42px;
  border: 1px solid rgba(217, 226, 234, 0.88);
  border-radius: 8px;
  background:
    linear-gradient(120deg, rgba(255, 255, 255, 0.92), rgba(255, 255, 255, 0.64)),
    url("./assets/classics/qianli-jiangshan-tu.jpg") center 42% / cover;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.intro-copy {
  max-width: 760px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--teal);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.intro h1 {
  margin: 0;
  max-width: 760px;
  font-size: clamp(34px, 5vw, 64px);
  line-height: 1.06;
  letter-spacing: 0;
}

.intro-copy > p:last-child {
  max-width: 720px;
  margin: 18px 0 0;
  color: #354156;
  font-size: 17px;
}

.intro-panel {
  display: grid;
  gap: 10px;
  align-self: stretch;
  justify-content: stretch;
}

.intro-panel span {
  display: flex;
  align-items: center;
  min-height: 52px;
  padding: 12px 16px;
  border: 1px solid rgba(217, 226, 234, 0.9);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.86);
  color: #2b3748;
  font-weight: 800;
}

.gallery-shell {
  display: grid;
  grid-template-columns: minmax(220px, 280px) minmax(0, 1fr) minmax(220px, 280px);
  gap: 24px;
  margin-top: 28px;
  align-items: start;
}

.filters,
.featured-list {
  position: sticky;
  top: 90px;
  display: grid;
  gap: 22px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 8px 26px rgba(23, 32, 51, 0.07);
}

.search-block label,
.filter-group p,
.featured-list h2 {
  margin: 0 0 10px;
  color: #283449;
  font-size: 14px;
  font-weight: 900;
}

.search-block input {
  width: 100%;
  min-height: 44px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  color: var(--ink);
  outline: none;
}

.search-block input:focus {
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.14);
}

.filter-group {
  display: grid;
  gap: 8px;
}

.filter-button,
.sort-button {
  min-height: 40px;
  padding: 9px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f8fafc;
  color: #344054;
  cursor: pointer;
  font-weight: 800;
  transition: background 160ms ease, color 160ms ease, border-color 160ms ease;
}

.filter-button {
  width: 100%;
  text-align: left;
}

.filter-button:hover,
.sort-button:hover {
  border-color: rgba(37, 99, 235, 0.42);
  background: #eef4ff;
}

.filter-button.active,
.sort-button.active {
  border-color: var(--blue);
  background: var(--blue);
  color: white;
}

.gallery-main {
  min-width: 0;
}

.gallery-toolbar {
  min-height: 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 16px;
}

.gallery-toolbar p {
  margin: 0;
  color: var(--muted);
  font-weight: 800;
}

.gallery-toolbar strong,
#result-count span {
  color: var(--teal);
}

.sort-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: flex-end;
}

.art-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.art-card {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: 0 10px 26px rgba(23, 32, 51, 0.08);
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.art-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 18px 42px rgba(23, 32, 51, 0.14);
}

.art-image {
  position: relative;
  aspect-ratio: 1 / 1;
  overflow: hidden;
  background: #eef1f5;
}

.art-image img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
  transition: transform 420ms ease;
}

.art-card:hover .art-image img {
  transform: scale(1.045);
}

.art-meta {
  padding: 16px;
}

.art-meta h3 {
  margin: 0 0 6px;
  font-size: 18px;
  line-height: 1.32;
}

.art-meta p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.art-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 12px;
}

.art-tags span {
  padding: 4px 8px;
  border-radius: 999px;
  background: #eef4f8;
  color: #395066;
  font-size: 12px;
  font-weight: 800;
}

.featured-list h2 {
  font-size: 18px;
}

.featured-item {
  display: grid;
  grid-template-columns: 68px minmax(0, 1fr);
  gap: 12px;
  align-items: center;
  padding: 8px;
  border-radius: 8px;
}

.featured-item:hover {
  background: var(--surface-soft);
}

.featured-item img {
  width: 68px;
  height: 68px;
  object-fit: cover;
  border-radius: 8px;
}

.featured-item strong {
  display: block;
  overflow: hidden;
  color: var(--ink);
  font-size: 14px;
  line-height: 1.35;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.featured-item span {
  display: block;
  overflow: hidden;
  color: var(--muted);
  font-size: 12px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.empty-state {
  min-height: 260px;
  display: grid;
  place-items: center;
  gap: 6px;
  border: 1px dashed var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.78);
  color: var(--muted);
  text-align: center;
}

.empty-state strong {
  color: var(--ink);
  font-size: 18px;
}

.site-footer {
  max-width: 1440px;
  margin: 0 auto;
  padding: 22px 24px 34px;
  color: var(--muted);
  font-size: 13px;
  text-align: center;
}

.site-footer p {
  margin: 4px 0;
}

@media (max-width: 1120px) {
  .gallery-shell {
    grid-template-columns: minmax(220px, 280px) minmax(0, 1fr);
  }

  .featured-list {
    position: static;
    grid-column: 1 / -1;
  }

  #featured-list {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 8px;
  }
}

@media (max-width: 860px) {
  .header-inner {
    padding: 12px 16px;
  }

  .top-nav {
    display: none;
  }

  main {
    padding: 20px 16px 30px;
  }

  .intro {
    grid-template-columns: 1fr;
    padding: 28px 22px;
  }

  .intro-panel {
    grid-template-columns: 1fr;
  }

  .gallery-shell {
    grid-template-columns: 1fr;
  }

  .filters,
  .featured-list {
    position: static;
  }

  .filter-group {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .filter-group p {
    grid-column: 1 / -1;
  }

  .filter-button {
    text-align: center;
  }

  .gallery-toolbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .sort-buttons {
    justify-content: flex-start;
  }

  .art-grid,
  #featured-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 520px) {
  .brand-copy strong {
    font-size: 18px;
  }

  .intro h1 {
    font-size: 32px;
  }

  .intro-copy > p:last-child {
    font-size: 15px;
  }

  .filter-group {
    grid-template-columns: 1fr;
  }

  .sort-button {
    flex: 1 1 100px;
  }
}