:root {
  --primary: #4f6ef7;
  --primary-dark: #3b54d6;
  --primary-light: #eef1fe;
  --text: #1f2430;
  --text-secondary: #6b7280;
  --bg: #f7f8fc;
  --card-bg: #ffffff;
  --border: #e5e7eb;
  --radius: 14px;
  --shadow: 0 2px 10px rgba(31, 36, 48, 0.06);
  --shadow-hover: 0 8px 24px rgba(31, 36, 48, 0.12);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.site-header {
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
  background: rgba(255, 255, 255, 0.92);
}

.site-header .container {
  display: flex;
  align-items: center;
  gap: 12px;
  height: 60px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text);
}

.brand-mark {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--primary), #7c5cf7);
  color: #fff;
  font-weight: 700;
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.brand-name {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.brand-sub {
  font-size: 12px;
  color: var(--text-secondary);
  background: var(--primary-light);
  color: var(--primary-dark);
  padding: 3px 10px;
  border-radius: 999px;
  font-weight: 500;
}

/* Hero */
.hero {
  padding: 48px 0 28px;
}

.hero-title {
  font-size: 32px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 8px;
}

.hero-desc {
  text-align: center;
  color: var(--text-secondary);
  margin-bottom: 28px;
}

.search-box {
  display: flex;
  gap: 10px;
  max-width: 640px;
  margin: 0 auto;
}

.search-box input {
  flex: 1;
  height: 50px;
  padding: 0 20px;
  font-size: 15px;
  border: 2px solid var(--border);
  border-radius: var(--radius);
  background: var(--card-bg);
  color: var(--text);
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.search-box input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(79, 110, 247, 0.12);
}

.search-box button {
  width: 100px;
  height: 50px;
  border: none;
  border-radius: var(--radius);
  background: var(--primary);
  color: #fff;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

.search-box button:hover {
  background: var(--primary-dark);
}

.search-box button:active {
  transform: scale(0.97);
}

.search-box button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.hot-tags {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}

.hot-label {
  font-size: 13px;
  color: var(--text-secondary);
}

.tag {
  border: 1px solid var(--border);
  background: var(--card-bg);
  color: var(--text-secondary);
  font-size: 13px;
  padding: 5px 14px;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.2s;
}

.tag:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-light);
}

/* Gallery */
.gallery-section {
  flex: 1;
  padding-bottom: 48px;
}

.gallery-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 20px;
}

.result-info {
  font-size: 14px;
  color: var(--text-secondary);
}

.result-info strong {
  color: var(--text);
}

.gallery-controls {
  display: flex;
  align-items: center;
  gap: 12px;
}

.num-label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--text-secondary);
}

.num-label select {
  height: 34px;
  padding: 0 8px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--card-bg);
  color: var(--text);
  font-size: 13px;
  outline: none;
  cursor: pointer;
}

.btn-random {
  height: 34px;
  padding: 0 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--card-bg);
  color: var(--text);
  font-size: 13px;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-random:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-light);
}

.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
}

.card {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--card-bg);
  box-shadow: var(--shadow);
  cursor: pointer;
  transition: transform 0.25s, box-shadow 0.25s;
  border: 1px solid var(--border);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}

.card img {
  display: block;
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
  transition: transform 0.35s;
}

.card:hover img {
  transform: scale(1.05);
}

.card-mask {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 40%, rgba(15, 18, 30, 0.72));
  opacity: 0;
  transition: opacity 0.25s;
  display: flex;
  align-items: flex-end;
  padding: 12px;
}

.card:hover .card-mask {
  opacity: 1;
}

.card-info {
  width: 100%;
  color: #fff;
}

.card-title {
  font-size: 13px;
  font-weight: 600;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.card-sub {
  font-size: 11px;
  opacity: 0.85;
  margin-top: 2px;
}

/* State boxes */
.state-box {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 48px 0;
  color: var(--text-secondary);
  font-size: 14px;
}

.state-error {
  color: #d33;
}

.hidden {
  display: none !important;
}

.spinner {
  width: 20px;
  height: 20px;
  border: 2px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* Pagination */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-top: 28px;
}

.page-btn {
  height: 38px;
  padding: 0 20px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--card-bg);
  color: var(--text);
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s;
}

.page-btn:hover:not(:disabled) {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-light);
}

.page-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.page-info {
  font-size: 14px;
  color: var(--text-secondary);
  min-width: 120px;
  text-align: center;
}

/* Lightbox */
.lightbox {
  position: fixed;
  inset: 0;
  background: rgba(10, 12, 20, 0.85);
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  backdrop-filter: blur(4px);
}

.lightbox-body {
  max-width: 90vw;
  max-height: 88vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.lightbox-body img {
  max-width: 90vw;
  max-height: 78vh;
  border-radius: 12px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.5);
  object-fit: contain;
}

.lightbox-info {
  color: #e5e7eb;
  font-size: 13px;
  text-align: center;
}

.lightbox-close {
  position: absolute;
  top: 16px;
  right: 20px;
  width: 40px;
  height: 40px;
  border: none;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
  font-size: 24px;
  line-height: 1;
  cursor: pointer;
  transition: background 0.2s;
}

.lightbox-close:hover {
  background: rgba(255, 255, 255, 0.3);
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--card-bg);
  padding: 20px 0;
}

.site-footer .container {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 12px;
  color: var(--text-secondary);
}

/* Responsive */
@media (max-width: 640px) {
  .hero-title {
    font-size: 24px;
  }

  .hero {
    padding: 32px 0 20px;
  }

  .gallery {
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
  }

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

  .search-box button {
    width: 76px;
  }
}