/**
 * Post AJAX Filter — Stylesheet
 *
 * Phần:
 *  1. Custom properties (design tokens)
 *  2. Widget bộ lọc  (.paf-filter)
 *     a. Header + tiêu đề
 *     b. Danh sách Checkbox / Radio
 *     c. Dropdown
 *     d. Tab UI
 *     e. Tìm kiếm
 *  3. Danh sách bài viết  (.paf-post-list)
 *     a. Toolbar
 *     b. Loading overlay + spinner
 *     c. Bố cục lưới
 *     d. Card bài viết
 *     e. Phân trang
 *  4. Tiện ích / accessibility
 *
 * @package Post_Ajax_Filter
 */

/* =============================================================================
   1. Custom Properties
   ============================================================================= */

:root {
  --paf-primary: #2563eb;
  --paf-primary-dark: #1d4ed8;
  --paf-text: #1e293b;
  --paf-muted: #64748b;
  --paf-border: #e2e8f0;
  --paf-bg: #f8fafc;
  --paf-white: #ffffff;
  --paf-error: #dc2626;

  --paf-radius: 0.375rem;
  --paf-radius-lg: 0.625rem;
  --paf-radius-pill: 999px;

  --paf-shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --paf-shadow-md: 0 4px 16px rgba(0, 0, 0, 0.1);

  --paf-transition: 0.18s ease;
  --paf-gap: 1rem;
}

/* =============================================================================
   2. Widget Bộ Lọc
   ============================================================================= */

/* ---- Container ---- */

.paf-filter {
  background: var(--paf-white);
  border: 1px solid var(--paf-border);
  border-radius: var(--paf-radius-lg);
  margin-bottom: var(--paf-gap);
}

/* ---- 2a. Header ---- */

.paf-filter__header {
  padding: 0.875rem 1.25rem 0;
}

.paf-filter__title {
  margin: 0;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--paf-text);
  line-height: 1.3;
}

/* ---- Body ---- */

.paf-filter__body {
  padding: 0.75rem 1.25rem 1rem;
}

.paf-notice {
  margin: 0;
  color: var(--paf-muted);
  font-size: 0.875rem;
}

/* ---- 2b. Checkbox / Radio list ---- */

.paf-filter__list {
  list-style: none;
  margin: 0;
  padding: 0;
  max-height: 260px;
  overflow-y: auto;
  scrollbar-width: thin;
}

.paf-filter__item {
  margin-bottom: 0.5rem;
}

.paf-filter__item:last-child {
  margin-bottom: 0;
}

.paf-filter__label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  font-size: 0.9rem;
  color: var(--paf-text);
  transition: color var(--paf-transition);
}

.paf-filter__label:hover {
  color: var(--paf-primary);
}

.paf-filter__input[type="checkbox"],
.paf-filter__input[type="radio"] {
  accent-color: var(--paf-primary);
  width: 1rem;
  height: 1rem;
  flex-shrink: 0;
  cursor: pointer;
}

.paf-filter__label-text {
  flex: 1;
}

.paf-filter__count {
  color: var(--paf-muted);
  font-size: 0.8125rem;
}

/* ---- 2c. Dropdown ---- */

.paf-filter__dropdown-wrap {
  position: relative;
}

.paf-filter__select {
  width: 100%;
  border: 1px solid var(--paf-border);
  border-radius: var(--paf-radius);
  background: var(--paf-white);
  color: var(--paf-text);
  font-size: 0.9rem;
  cursor: pointer;
  transition:
    border-color var(--paf-transition),
    box-shadow var(--paf-transition);
}

.paf-filter__select:focus {
  outline: none;
  border-color: var(--paf-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.paf-filter__select:not([multiple]) {
  padding: 0.5rem 2.5rem 0.5rem 0.75rem;
  -webkit-appearance: none;
  appearance: none;
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%2364748b' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");
  background-position: right 0.5rem center;
  background-repeat: no-repeat;
  background-size: 1.5em 1.5em;
}

.paf-filter__select[multiple] {
  padding: 0.25rem 0;
  max-height: 200px;
  overflow-y: auto;
  scrollbar-width: thin;
  background-image: none;
}

.paf-filter__select[multiple] option {
  padding: 0.375rem 0.875rem;
  cursor: pointer;
}

.paf-filter__select[multiple] option:checked {
  background: linear-gradient(
    0deg,
    var(--paf-primary) 0%,
    var(--paf-primary) 100%
  );
  color: var(--paf-white);
}

/* ---- 2d. Tab UI ---- */

.paf-filter__tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem;
}

.paf-filter__tab {
  padding: 0.375rem 0.875rem;
  border: 1px solid var(--paf-border);
  border-radius: var(--paf-radius-pill);
  background: var(--paf-white);
  color: var(--paf-text);
  font-size: 0.875rem;
  cursor: pointer;
  transition: all var(--paf-transition);
  line-height: 1.4;
}

.paf-filter__tab:hover {
  border-color: var(--paf-primary);
  color: var(--paf-primary);
}

.paf-filter__tab.is-active {
  background: var(--paf-primary);
  border-color: var(--paf-primary);
  color: var(--paf-white);
}

/* ---- 2e. Tìm kiếm ---- */

.paf-filter__search-wrap {
  position: relative;
}

.paf-filter__search {
  width: 100%;
  padding: 0.5rem 0.875rem;
  border: 1px solid var(--paf-border);
  border-radius: var(--paf-radius);
  font-size: 0.9rem;
  color: var(--paf-text);
  background: var(--paf-white);
  transition:
    border-color var(--paf-transition),
    box-shadow var(--paf-transition);
  box-sizing: border-box;
}

.paf-filter__search:focus {
  outline: none;
  border-color: var(--paf-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.paf-filter__search::placeholder {
  color: var(--paf-muted);
}

/* =============================================================================
   3. Danh Sách Bài Viết
   ============================================================================= */

.paf-post-list {
  position: relative;
}

/* ---- 3a. Toolbar ---- */

.paf-post-list__toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--paf-border);
}

.paf-post-list__results-count {
  margin: 0;
  font-size: 0.875rem;
  color: var(--paf-muted);
}

.paf-post-list__toolbar-controls {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.625rem;
}

.paf-post-list__orderby {
  padding: 0.4rem 2.25rem 0.4rem 0.75rem;
  border: 1px solid var(--paf-border);
  border-radius: var(--paf-radius);
  background: var(--paf-white);
  color: var(--paf-text);
  font-size: 0.875rem;
  cursor: pointer;
  -webkit-appearance: none;
  appearance: none;
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%2364748b' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");
  background-position: right 0.4rem center;
  background-repeat: no-repeat;
  background-size: 1.25em 1.25em;
  transition: border-color var(--paf-transition);
}

.paf-post-list__orderby:focus {
  outline: none;
  border-color: var(--paf-primary);
}

/* ---- 3b. Loading overlay + spinner ---- */

.paf-post-list__loading {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.75);
  backdrop-filter: blur(2px);
  border-radius: var(--paf-radius-lg);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--paf-transition);
  z-index: 10;
}

.paf-post-list.is-loading .paf-post-list__loading {
  opacity: 1;
  pointer-events: all;
}

.paf-spinner {
  width: 44px;
  height: 44px;
  border: 3px solid var(--paf-border);
  border-top-color: var(--paf-primary);
  border-radius: 50%;
  animation: paf-spin 0.7s linear infinite;
}

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

/* ---- 3c. Bố cục lưới ---- */

.paf-post-list__grid {
  display: grid;
  grid-template-columns: repeat(var(--paf-cols, 3), 1fr);
  gap: 1.5rem;
}

@media (max-width: 1024px) {
  .paf-post-list__grid {
    grid-template-columns: repeat(var(--paf-cols-tablet, 2), 1fr);
  }
}

@media (max-width: 600px) {
  .paf-post-list__grid {
    grid-template-columns: repeat(var(--paf-cols-mobile, 1), 1fr);
    gap: 1rem;
  }
}

.paf-no-posts {
  grid-column: 1 / -1;
  text-align: center;
  padding: 3.5rem 1rem;
  color: var(--paf-muted);
  font-size: 0.9375rem;
}

/* ---- 3d. Card bài viết ---- */

.paf-post-card {
  background: var(--paf-white);
  border: 1px solid var(--paf-border);
  border-radius: var(--paf-radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition:
    box-shadow var(--paf-transition),
    transform var(--paf-transition);
}

.paf-post-card:hover {
  box-shadow: var(--paf-shadow-md);
  transform: translateY(-2px);
}

.paf-post-card__thumbnail {
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: var(--paf-bg);
}

.paf-post-card__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
  display: block;
}

.paf-post-card:hover .paf-post-card__img {
  transform: scale(1.04);
}

.paf-post-card__body {
  padding: 1.125rem 1.25rem 1.25rem;
  display: flex;
  flex-direction: column;
  flex: 1;
  gap: 0.625rem;
}

.paf-post-card__cats {
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem;
}

.paf-post-card__cat {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--paf-primary);
  text-decoration: none;
  transition: color var(--paf-transition);
}

.paf-post-card__cat:hover {
  color: var(--paf-primary-dark);
}

.paf-post-card__title {
  margin: 0;
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--paf-text);
}

.paf-post-card__title a {
  color: inherit;
  text-decoration: none;
  transition: color var(--paf-transition);
}

.paf-post-card__title a:hover {
  color: var(--paf-primary);
}

.paf-post-card__excerpt {
  margin: 0;
  font-size: 0.875rem;
  color: var(--paf-muted);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  flex: 1;
}

.paf-post-card__meta {
  display: flex;
  align-items: center;
  gap: 0.375rem;
  font-size: 0.8125rem;
  color: var(--paf-muted);
  margin-top: auto;
  padding-top: 0.625rem;
  border-top: 1px solid var(--paf-border);
}

.paf-post-card__author a {
  color: var(--paf-text);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--paf-transition);
}

.paf-post-card__author a:hover {
  color: var(--paf-primary);
}

.paf-post-card__sep {
  color: var(--paf-border);
}

.paf-post-card__date {
  color: var(--paf-muted);
}

/* ---- 3e. Phân trang ---- */

.paf-post-list__pagination {
  margin-top: 2rem;
}

.paf-pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.375rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--paf-border);
}

.paf-pagination__btn {
  min-width: 2.25rem;
  height: 2.25rem;
  padding: 0 0.625rem;
  background: var(--paf-white);
  border: 1px solid var(--paf-border);
  border-radius: var(--paf-radius);
  font-size: 0.875rem;
  cursor: pointer;
  color: var(--paf-text);
  transition: all var(--paf-transition);
  line-height: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.paf-pagination__btn:hover {
  background: var(--paf-primary);
  border-color: var(--paf-primary);
  color: var(--paf-white);
}

.paf-pagination__btn--current {
  background: var(--paf-primary);
  border-color: var(--paf-primary);
  color: var(--paf-white);
  font-weight: 600;
  pointer-events: none;
}

.paf-pagination__btn--prev,
.paf-pagination__btn--next {
  padding: 0 0.875rem;
}

.paf-pagination__ellipsis {
  padding: 0 0.25rem;
  color: var(--paf-muted);
  line-height: 2.25rem;
  display: inline-flex;
  align-items: center;
}

/* =============================================================================
   4. Lỗi
   ============================================================================= */

.paf-error {
  text-align: center;
  padding: 2.5rem 1rem;
  color: var(--paf-error);
  font-size: 0.9375rem;
}

/* =============================================================================
   5. Accessibility — Screen-reader only
   ============================================================================= */

.screen-reader-text {
  border: 0;
  clip: rect(1px, 1px, 1px, 1px);
  clip-path: inset(50%);
  height: 1px;
  margin: -1px;
  overflow: hidden;
  padding: 0;
  position: absolute;
  width: 1px;
  word-wrap: normal !important;
}

.screen-reader-text:focus {
  background: var(--paf-bg);
  clip: auto !important;
  clip-path: none;
  color: var(--paf-text);
  display: block;
  font-size: 0.875rem;
  font-weight: 700;
  height: auto;
  left: 0.5rem;
  line-height: normal;
  padding: 0.875rem 1.25rem;
  top: 0.5rem;
  width: auto;
  z-index: 100000;
}