/* ============================================
   World Data Foundation — Datasets Page Styles
   ============================================ */

/* --- Datasets Hero --- */
.datasets-hero {
  background-color: var(--color-navy);
  padding: 140px 24px 60px;
  text-align: center;
}

.datasets-hero h1 {
  font-family: var(--font-heading);
  font-size: 2.25rem;
  color: var(--color-white);
  letter-spacing: 3px;
  margin-bottom: 12px;
}

.datasets-hero p {
  color: var(--color-silver);
  font-size: 1.125rem;
  max-width: 600px;
  margin: 0 auto 32px;
}

/* --- Search Bar --- */
.datasets-search {
  max-width: 560px;
  margin: 0 auto;
  position: relative;
}

.datasets-search input {
  width: 100%;
  padding: 14px 20px 14px 48px;
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--color-text);
  background-color: var(--color-white);
  border: none;
  border-radius: 6px;
  outline: none;
  transition: box-shadow var(--transition);
}

.datasets-search input::placeholder {
  color: var(--color-text-light);
}

.datasets-search input:focus {
  box-shadow: 0 0 0 3px rgba(74, 144, 217, 0.3);
}

.datasets-search-icon {
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  width: 20px;
  height: 20px;
  color: var(--color-text-light);
  pointer-events: none;
}

/* --- Filters --- */
.datasets-filters {
  background-color: var(--color-white);
  border-bottom: 1px solid var(--color-border);
  padding: 20px 0;
  position: sticky;
  top: var(--nav-height);
  z-index: 100;
}

.filters-container {
  display: flex;
  align-items: center;
  gap: 10px;
  overflow-x: auto;
  padding-bottom: 4px;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

.filters-container::-webkit-scrollbar {
  display: none;
}

.filter-pill {
  display: inline-flex;
  align-items: center;
  padding: 8px 18px;
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-text-light);
  background-color: var(--color-grey-bg);
  border: 1px solid var(--color-border);
  border-radius: 100px;
  cursor: pointer;
  white-space: nowrap;
  transition: all var(--transition);
  letter-spacing: 0.3px;
}

.filter-pill:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
  background-color: rgba(74, 144, 217, 0.06);
}

.filter-pill.active {
  color: var(--color-white);
  background-color: var(--color-accent);
  border-color: var(--color-accent);
}

/* --- Dataset Grid --- */
.datasets-section {
  background-color: var(--color-grey-bg);
  padding: 48px 0 80px;
  min-height: 400px;
}

.datasets-count {
  color: var(--color-text-light);
  font-size: 0.875rem;
  margin-bottom: 24px;
}

.datasets-count strong {
  color: var(--color-text);
}

.datasets-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

/* --- Dataset Card --- */
.dataset-card {
  background-color: var(--color-white);
  border-radius: 8px;
  border: 1px solid var(--color-border);
  padding: 28px;
  transition: transform var(--transition), box-shadow var(--transition);
  display: flex;
  flex-direction: column;
}

.dataset-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(10, 26, 58, 0.08);
}

.dataset-card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.dataset-card-header h3 {
  font-size: 1.125rem;
  font-family: var(--font-heading);
  color: var(--color-navy);
  line-height: 1.3;
}

.badge-certified {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  font-family: var(--font-body);
  font-size: 0.6875rem;
  font-weight: 600;
  color: var(--color-accent);
  background-color: rgba(74, 144, 217, 0.1);
  border-radius: 100px;
  white-space: nowrap;
  letter-spacing: 0.3px;
  text-transform: uppercase;
}

.badge-certified svg {
  width: 12px;
  height: 12px;
}

.dataset-card-description {
  color: var(--color-text-light);
  font-size: 0.9375rem;
  line-height: 1.6;
  margin-bottom: 16px;
  flex: 1;
}

.dataset-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 16px;
}

.dataset-tag {
  padding: 3px 10px;
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--color-text-light);
  background-color: var(--color-grey-bg);
  border-radius: 4px;
  text-transform: capitalize;
}

.dataset-card-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--color-border);
  margin-bottom: 16px;
}

.dataset-meta-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8125rem;
  color: var(--color-text-light);
}

.dataset-meta-item svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
  opacity: 0.6;
}

.dataset-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.dataset-source {
  font-size: 0.8125rem;
  color: var(--color-text-light);
}

.dataset-source a {
  color: var(--color-accent);
  font-weight: 500;
}

.dataset-source a:hover {
  text-decoration: underline;
}

.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-white);
  background-color: var(--color-accent);
  border: none;
  border-radius: 4px;
  cursor: pointer;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  transition: background-color var(--transition), transform var(--transition);
  white-space: nowrap;
}

.btn-download:hover {
  background-color: var(--color-accent-hover);
  transform: translateY(-1px);
}

.btn-download svg {
  width: 14px;
  height: 14px;
}

/* --- Loading State --- */
.datasets-loading {
  text-align: center;
  padding: 80px 24px;
  color: var(--color-text-light);
}

.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-accent);
  border-radius: 50%;
  margin: 0 auto 16px;
  animation: spin 0.8s linear infinite;
}

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

/* --- Empty State --- */
.datasets-empty {
  text-align: center;
  padding: 80px 24px;
  color: var(--color-text-light);
}

.datasets-empty svg {
  width: 64px;
  height: 64px;
  margin: 0 auto 16px;
  color: var(--color-border);
}

.datasets-empty h3 {
  color: var(--color-text);
  margin-bottom: 8px;
  font-size: 1.25rem;
}

.datasets-empty p {
  font-size: 0.9375rem;
}

/* --- Error State --- */
.datasets-error {
  text-align: center;
  padding: 80px 24px;
  color: var(--color-text-light);
}

.datasets-error h3 {
  color: var(--color-text);
  margin-bottom: 8px;
  font-size: 1.25rem;
}

.datasets-error p {
  font-size: 0.9375rem;
  margin-bottom: 20px;
}

.btn-retry {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 24px;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-accent);
  background: none;
  border: 1px solid var(--color-accent);
  border-radius: 4px;
  cursor: pointer;
  transition: all var(--transition);
}

.btn-retry:hover {
  background-color: var(--color-accent);
  color: var(--color-white);
}

/* --- Responsive --- */
@media (min-width: 640px) {
  .datasets-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 768px) {
  .datasets-hero {
    padding: 160px 24px 72px;
  }

  .datasets-hero h1 {
    font-size: 2.75rem;
    letter-spacing: 5px;
  }
}

@media (min-width: 1024px) {
  .datasets-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .datasets-hero h1 {
    font-size: 3rem;
  }
}