*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  margin: 0;
  --primary-bg-color: #f4f4f4;
  --secondary-bg-color: #ffffff;
  --text-color: #333333;
  --subtle-text-color: #666;
  --accent-color: #007bff;
  --accent-color-rgb: 0, 123, 255;
  --border-color: #e0e0e0;
  background-color: var(--primary-bg-color);
  color: var(--text-color);
  transition: background-color 0.3s, color 0.3s;
}
body.dark-theme {
  --primary-bg-color: #1a1a1a;
  --secondary-bg-color: #2c2c2c;
  --text-color: #f4f4f4;
  --subtle-text-color: #aaa;
  --accent-color: #00aaff;
  --accent-color-rgb: 0, 170, 255;
  --border-color: #444444;
}
body.body-no-scroll {
  overflow: hidden;
}

.feedContainer {
  display: flex;
  height: 100vh;
  width: 100%;
  overflow: hidden;
}

.sidebar {
  width: 280px;
  background-color: var(--primary-bg-color);
  border-right: 1px solid var(--border-color);
  padding: 25px 15px;
  display: flex;
  flex-direction: column;
  transition: transform 0.3s ease-in-out;
  flex-shrink: 0;
}
.sidebar .sidebar-header {
  margin-bottom: 30px;
  padding-left: 15px;
}
.sidebar .sidebar-header h2 {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text-color);
  display: flex;
  align-items: center;
}
.sidebar .feed-list-wrapper {
  overflow-y: auto;
  flex-grow: 1;
}
.sidebar .feed-list-wrapper .category-group {
  margin-bottom: 10px;
}
.sidebar .feed-list-wrapper .category-group .category-toggle {
  display: none;
}
.sidebar .feed-list-wrapper .category-group .category-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 15px;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--subtle-text-color);
  border-radius: 8px;
}
.sidebar .feed-list-wrapper .category-group .category-header:hover {
  background-color: var(--secondary-bg-color);
}
.sidebar .feed-list-wrapper .category-group .category-header .category-chevron {
  transition: transform 0.3s ease;
}
.sidebar .feed-list-wrapper .category-group .category-header .category-chevron.expanded {
  transform: rotate(180deg);
}
.sidebar .feed-list-wrapper .category-group .feed-list {
  list-style: none;
  padding: 0 0 0 15px;
  margin: 0;
  position: relative;
  overflow: hidden;
  max-height: 0;
  transition: margin-top 0.35s ease-in-out;
}
.sidebar .feed-list-wrapper .category-group .feed-list > ul {
  overflow: hidden;
}
.sidebar .feed-list-wrapper .category-group .feed-list.expanded {
  max-height: 500px;
  margin-top: 5px;
}
.sidebar .feed-list-wrapper .category-group .feed-list::before {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 48px;
  border-radius: 12px;
  z-index: 1;
  top: var(--active-top, 0);
}
.sidebar .feed-list-wrapper .category-group .feed-list li {
  padding: 12px 20px;
  cursor: pointer;
  border-radius: 12px;
  margin-bottom: 10px;
  font-weight: 500;
  color: var(--subtle-text-color);
  transition: color 0.3s ease;
  position: relative;
  z-index: 2;
}
.sidebar .feed-list-wrapper .category-group .feed-list li:hover:not(.active) {
  color: var(--text-color);
}
.sidebar .feed-list-wrapper .category-group .feed-list li.active {
  background-color: var(--secondary-bg-color);
  color: var(--text-color);
  font-weight: 600;
}
.sidebar .feed-list-wrapper .category-group .category-toggle:checked + .category-header .category-chevron {
  transform: rotate(180deg);
}
.sidebar .feed-list-wrapper .category-group .category-toggle:checked + .category-header + .feed-list {
  max-height: 500px;
  margin-top: 5px;
}
.sidebar .sidebar-footer {
  margin-top: auto;
  padding-top: 15px;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.sidebar .sidebar-footer .dropdown .btn {
  width: 50px;
  background-color: var(--secondary-bg-color);
  border-color: var(--border-color);
  color: var(--text-color);
}
.sidebar .sidebar-footer .dropdown .btn:hover {
  background-color: var(--primary-bg-color);
  border-color: var(--accent-color);
}
.sidebar .sidebar-footer .dropdown .dropdown-menu {
  min-width: auto;
  width: 50px;
}
.sidebar .sidebar-footer .github-link {
  font-size: 1.5rem;
  color: var(--subtle-text-color);
  padding: 8px;
  border-radius: 8px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: color 0.2s ease, background-color 0.2s ease;
}
.sidebar .sidebar-footer .github-link:hover {
  color: var(--text-color);
  background-color: var(--primary-bg-color);
}

.main-content {
  flex: 1;
  padding: 20px 30px;
  overflow-y: auto;
  transition: width 0.3s ease-in-out;
}
.main-content .main-header {
  margin-bottom: 20px;
}
.main-content .main-header h3 {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0;
}
.main-content .main-header h3 i {
  font-weight: 700;
}
.main-content .main-header h3 span {
  color: var(--subtle-text-color);
}
.main-content .main-header h6 {
  font-size: 12px;
  color: var(--subtle-text-color);
}

.article-view {
  flex-shrink: 0;
  width: 0;
  background-color: var(--secondary-bg-color);
  border-left: 1px solid var(--border-color);
  overflow-y: auto;
  overflow-x: hidden;
  padding: 0 0;
  transition: width 0.35s ease-in-out;
}
.article-view.open {
  width: 40%;
  padding: 30px;
}

.mobile-tab-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 60px;
  background-color: var(--secondary-bg-color);
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-around;
  align-items: center;
  z-index: 1050;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}
.mobile-tab-bar .dropdown {
  flex: 1;
  text-align: center;
}
.mobile-tab-bar .tab-item {
  flex: 1;
  width: 100%;
  text-align: center;
  color: var(--subtle-text-color);
  background: transparent;
  border: none;
  font-size: 0.75rem;
  font-weight: 500;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 5px 0;
  transition: color 0.3s ease;
}
.mobile-tab-bar .tab-item i {
  font-size: 1.1rem;
  margin-bottom: 2px;
}
.mobile-tab-bar .tab-item:hover {
  color: var(--text-color);
}
.mobile-tab-bar .tab-item.active {
  color: var(--accent-color);
  font-weight: 600;
}

.offcanvas {
  background-color: var(--secondary-bg-color);
  color: var(--text-color);
  transition: background-color 0.3s ease, color 0.3s ease;
  transition: transform 0.3s ease-in-out;
  min-height: 40%;
}
.offcanvas .offcanvas-header {
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 1.25rem;
}
.offcanvas .offcanvas-header .offcanvas-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-color);
}
.offcanvas .offcanvas-header .btn-close {
  filter: invert(0.6);
  transition: filter 0.3s ease;
}
.offcanvas .offcanvas-header .btn-close:hover {
  filter: invert(1);
}
.offcanvas .offcanvas-body {
  padding: 1rem;
}
.offcanvas .offcanvas-body .category-group {
  margin-bottom: 1.5rem;
}
.offcanvas .offcanvas-body .category-group h6 {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 0.75rem;
  color: var(--subtle-text-color);
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border-color);
}
.offcanvas .offcanvas-body .category-group ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
}
.offcanvas .offcanvas-body .category-group ul li {
  padding: 12px 14px;
  border-radius: 10px;
  background-color: var(--primary-bg-color);
  color: var(--subtle-text-color);
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.3s ease, color 0.3s ease, transform 0.2s ease;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.offcanvas .offcanvas-body .category-group ul li:hover {
  background-color: var(--secondary-bg-color);
  color: var(--text-color);
  transform: translateY(-2px);
}
.offcanvas .offcanvas-body .category-group ul li.active {
  background-color: var(--secondary-bg-color);
  color: var(--accent-color);
  font-weight: 600;
  position: relative;
}
.offcanvas .offcanvas-body .category-group ul li.active::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background-color: var(--accent-color);
  border-radius: 3px 0 0 3px;
}
.offcanvas .offcanvas-body .category-group ul li i {
  font-size: 1rem;
  opacity: 0.7;
  transition: opacity 0.3s ease;
}
.active .offcanvas .offcanvas-body .category-group ul li i {
  opacity: 1;
  color: var(--accent-color);
}

.article-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  padding-bottom: 75px;
}

.article-item {
  background-color: var(--secondary-bg-color);
  padding: 1.25rem;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  position: relative;
}
.article-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.07);
}
.article-item h3 {
  margin: 0 0 0.5rem 0;
  font-size: 1.2rem;
  line-height: 1.4;
}
.article-item .summary {
  margin: 0;
  font-size: 0.95rem;
  color: var(--subtle-text-color);
  line-height: 1.6;
}
.article-item .article-meta {
  margin-top: 1rem;
  font-size: 0.8rem;
  color: var(--subtle-text-color);
}
.article-item .direct-link {
  position: absolute;
  top: 1.25rem;
  right: 1.25rem;
  color: var(--subtle-text-color);
  opacity: 0.5;
  transition: opacity 0.2s;
}

#close-article-btn {
  margin-bottom: 10px;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text-color);
  cursor: pointer;
  margin-right: 1rem;
}

.overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 998;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease-in-out, visibility 0.3s ease-in-out;
}
.overlay.active {
  opacity: 1;
  visibility: visible;
}

.filter-controls {
  display: flex;
  align-items: center;
  gap: 16px;
}
.filter-controls .date-filter-controls {
  display: flex;
  justify-content: center;
  align-items: center;
}
.filter-controls .date-filter-controls .input-group {
  box-shadow: none;
  max-width: 400px;
}
.filter-controls .date-filter-controls .input-group .btn, .filter-controls .date-filter-controls .input-group .input-group-text {
  background-color: var(--secondary-bg-color);
  color: var(--text-color);
  border: 1px solid var(--border-color);
  box-shadow: none;
  transition: all 0.2s ease-in-out;
}
.filter-controls .date-filter-controls .input-group .btn:hover {
  transform: translateY(-1px);
  background-color: var(--primary-bg-color);
  color: var(--accent-color);
  border-color: var(--accent-color);
  z-index: 2;
}
.filter-controls .date-filter-controls .input-group .input-group-text {
  font-weight: 500;
}
.filter-controls .date-filter-controls .input-group .input-group-text:hover {
  color: var(--accent-color);
  background-color: var(--primary-bg-color);
}
.filter-controls .date-filter-controls .input-group > :not(:last-child) {
  border-top-right-radius: 0;
  border-bottom-right-radius: 0;
}
.filter-controls .date-filter-controls .input-group > :not(:first-child) {
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
}
.filter-controls .pagination {
  margin: 0;
}
.filter-controls .pagination .page-item {
  transition: transform 0.2s ease-in-out;
}
.filter-controls .pagination .page-item:not(.disabled):hover {
  transform: translateY(-1px);
}
.filter-controls .pagination .page-item:first-child .page-link {
  border-top-left-radius: 8px;
  border-bottom-left-radius: 8px;
}
.filter-controls .pagination .page-item:last-child .page-link {
  border-top-right-radius: 8px;
  border-bottom-right-radius: 8px;
}
.filter-controls .pagination .page-item.active .page-link {
  background-color: var(--accent-color);
  border-color: var(--accent-color);
  color: #fff;
  z-index: 3;
}
.filter-controls .pagination .page-item.disabled .page-link {
  background-color: var(--primary-bg-color);
  opacity: 0.6;
  cursor: not-allowed;
}
.filter-controls .pagination .page-link {
  background-color: var(--secondary-bg-color);
  color: var(--text-color);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  margin: 0 4px;
  box-shadow: none;
  transition: all 0.2s ease-in-out;
}
.filter-controls .pagination .page-link:hover {
  background-color: var(--primary-bg-color);
  color: var(--accent-color);
  border-color: var(--accent-color);
  z-index: 2;
}
.filter-controls .pagination .page-link:focus {
  box-shadow: 0 0 0 2px rgba(var(--accent-color-rgb, 0, 123, 255), 0.4);
  border-color: var(--accent-color);
}
.filter-controls .btn-refresh {
  background-color: var(--secondary-bg-color);
  color: var(--text-color);
  border: 1px solid var(--border-color);
  transition: all 0.2s ease-in-out;
  display: flex;
  align-items: center;
  justify-content: center;
}
.filter-controls .btn-refresh:hover:not(:disabled) {
  background-color: var(--primary-bg-color);
  color: var(--accent-color);
  border-color: var(--accent-color);
}
.filter-controls .btn-refresh:disabled {
  opacity: 0.7;
  cursor: not-allowed;
}
.filter-controls .btn-refresh .bi-arrow-clockwise {
  transition: transform 0.5s ease;
}
.filter-controls .btn-refresh .fa-spin {
  animation: fa-spin 1s infinite linear;
}
@keyframes fa-spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

.empty-state-banner {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 60px 20px;
  background-color: var(--secondary-bg-color);
  border: 1px dashed var(--border-color);
  border-radius: 16px;
  opacity: 0.7;
}
.empty-state-banner .empty-state-icon {
  font-size: 3.5rem;
  line-height: 1;
  color: var(--accent-color);
  margin-bottom: 20px;
}
.empty-state-banner .empty-state-title {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-color);
  margin-bottom: 8px;
}
.empty-state-banner .empty-state-text {
  font-size: 1rem;
  color: var(--subtle-text-color);
  max-width: 640px;
  line-height: 1.6;
}

@keyframes skeleton-glow {
  0% {
    background-position: -200px 0;
  }
  100% {
    background-position: calc(200px + 100%) 0;
  }
}
.skeleton-loader-wrapper {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.skeleton-article-item {
  background-color: var(--secondary-bg-color);
  padding: 1.25rem;
  border-radius: 12px;
  border: 1px solid var(--border-color);
}
.skeleton-article-item .skeleton-line {
  height: 16px;
  border-radius: 8px;
  margin-bottom: 12px;
  background-color: var(--primary-bg-color);
  background-image: linear-gradient(90deg, var(--primary-bg-color), var(--secondary-bg-color), var(--primary-bg-color));
  background-size: 200px 100%;
  background-repeat: no-repeat;
  animation: skeleton-glow 1.5s infinite linear;
}
.skeleton-article-item .skeleton-line.title {
  height: 24px;
  width: 70%;
  margin-bottom: 16px;
}
.skeleton-article-item .skeleton-line.text {
  width: 100%;
}
.skeleton-article-item .skeleton-line.short {
  width: 80%;
}
.skeleton-article-item .skeleton-line.meta {
  height: 12px;
  width: 30%;
  margin-top: 16px;
  margin-bottom: 0;
}

img {
  width: 100%;
  margin: 16px 0;
}

@media (max-width: 800px) {
  .container {
    display: block;
  }
  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    height: 100%;
    z-index: 1000;
    transform: translateX(-100%);
  }
  .sidebar .sidebar-header {
    display: flex;
    flex-direction: column;
  }
  .sidebar.open {
    transform: translateX(0);
  }
  .menu-toggle {
    display: block;
  }
  .main-header {
    display: flex;
    align-items: center;
  }
  .main-header .title {
    flex-direction: column;
  }
  .main-header .title h3 {
    margin: 0;
  }
  .filter-controls {
    flex-direction: column;
  }
  .main-content {
    padding: 15px;
  }
  .article-view {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border-left: none;
    z-index: 1001;
    transform: translateX(100%);
    padding: 0;
    transition: transform 0.3s ease-in-out;
  }
  .article-view.open {
    transform: translateX(0);
    padding: 20px;
    width: 100%;
  }
}