.header {
  background: linear-gradient(135deg, #90b8c9, #b4d3dd);
  position: sticky;
  top: 0;
  z-index: 100
}

.header .header-container {
  box-sizing: border-box;
  max-width: 1400px;
  margin: 0 auto;
  padding: 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center
}

.header .header-container .logo {
  display: flex;
  align-items: center
}

.header .header-container .logo img {
  height: 40px;
  margin-right: .5rem
}

.header .header-container .logo .logo-text {
  font-size: 1.5rem;
  font-weight: 700;
  color: #f2f7fa;
  text-transform: uppercase
}

.header .header-container .logo .logo-text span {
  color: #d4e2e9
}

.header .header-container .nav-menu {
  display: flex;
  align-items: center
}

.header .header-container .nav-menu .nav-list {
  display: flex
}

.header .header-container .nav-menu .nav-list .nav-item {
  margin-right: 2rem
}

.header .header-container .nav-menu .nav-list .nav-item a {
  color: #4a6e7c;
  font-weight: 600;
  transition: color .2s;
  position: relative;
  padding-bottom: 5px;
  display: flex;
  gap: .4rem
}

.header .header-container .nav-menu .nav-list .nav-item a:hover,
.header .header-container .nav-menu .nav-list .nav-item a.active {
  color: #395766
}

.header .header-container .nav-menu .nav-list .nav-item a:hover:after,
.header .header-container .nav-menu .nav-list .nav-item a.active:after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: #7a9faa;
  border-radius: 1px
}

.header .header-container .nav-menu .nav-toggle {
  display: none;
  background: none;
  border: none;
  width: 30px;
  height: 30px;
  cursor: pointer;
  position: relative
}

.header .header-container .nav-menu .nav-toggle span {
  display: block;
  position: absolute;
  height: 3px;
  width: 100%;
  background: #4a6e7c;
  border-radius: 3px;
  transition: all .3s ease
}

.header .header-container .nav-menu .nav-toggle span:nth-child(1) {
  top: 6px
}

.header .header-container .nav-menu .nav-toggle span:nth-child(2) {
  top: 14px
}

.header .header-container .nav-menu .nav-toggle span:nth-child(3) {
  top: 22px
}

.header .header-container .nav-menu .nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg);
  top: 14px
}

.header .header-container .nav-menu .nav-toggle.active span:nth-child(2) {
  opacity: 0
}

.header .header-container .nav-menu .nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg);
  top: 14px
}

@media screen and (max-width: 768px) {
  .header .header-container .nav-menu .nav-list {
    position: fixed;
    top: 70px;
    left: 0;
    width: 100%;
    background: linear-gradient(135deg, #90b8c9, #b4d3dd);
    flex-direction: column;
    padding: 1rem 0;
    box-shadow: 0 5px 10px #0000001a;
    transform: translateY(-150%);
    transition: transform .3s ease
  }

  .header .header-container .nav-menu .nav-list.active {
    transform: translateY(0)
  }

  .header .header-container .nav-menu .nav-list .nav-item {
    margin: 0;
    width: 100%;
    text-align: center
  }

  .header .header-container .nav-menu .nav-list .nav-item a {
    display: block;
    padding: 1rem;
    color: #4a6e7c;
    display: flex;
    gap: .4rem
  }

  .header .header-container .nav-menu .nav-list .nav-item a:hover,
  .header .header-container .nav-menu .nav-list .nav-item a.active {
    color: #395766
  }

  .header .header-container .nav-menu .nav-list .nav-item a:hover:after,
  .header .header-container .nav-menu .nav-list .nav-item a.active:after {
    display: none
  }

  .header .header-container .nav-menu .nav-toggle {
    display: block
  }
}

.footer {
  background: linear-gradient(135deg, #90b8c9, #b4d3dd);
  color: #fff;
  padding: 3rem 0 2rem
}

.footer .footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem
}

.footer .footer-container .footer-top {
  display: flex;
  justify-content: center;
  margin-bottom: 1rem
}

.footer .footer-container .footer-top .footer-about {
  display: flex;
  flex-direction: column;
  justify-content: space-between
}

.footer .footer-container .footer-top .footer-about .logo {
  display: flex;
  align-items: center;
  justify-content: center
}

.footer .footer-container .footer-top .footer-about .logo img {
  height: 40px;
  margin-right: .5rem
}

.footer .footer-container .footer-top .footer-about .logo .logo-text {
  font-size: 1.5rem;
  font-weight: 700;
  color: #fff;
  text-transform: uppercase
}

.footer .footer-container .footer-top .footer-about .logo .logo-text span {
  color: #d4e2e9
}

.footer .footer-container .footer-top .footer-about p,
.footer .footer-container .footer-top .footer-about h2 {
  color: #4a6e7c;
  line-height: 1.6;
  font-size: 1.05rem;
  padding: 1rem 0;
  text-align: center
}

.footer .footer-container .footer-top .footer-about .social-links {
  display: flex;
  justify-content: center;
  gap: 1.2rem
}

.footer .footer-container .footer-top .footer-about .social-links a {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: #d4e2e9;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all .3s ease
}

.footer .footer-container .footer-top .footer-about .social-links a:hover {
  background: #395766;
  transform: translateY(-3px);
  box-shadow: 0 5px 15px #0003
}

.footer .footer-container .footer-top .footer-about .social-links a svg {
  width: 22px;
  height: 22px;
  fill: #fff
}

.footer .footer-container .footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, .1);
  padding-top: 1.8rem;
  display: flex;
  justify-content: space-between;
  align-items: center
}

.footer .footer-container .footer-bottom .copyright {
  color: #4a6e7c;
  font-size: .95rem
}

.footer .footer-container .footer-bottom .bottom-links {
  display: flex;
  gap: 2rem
}

.footer .footer-container .footer-bottom .bottom-links a {
  color: #4a6e7c;
  font-size: .95rem;
  transition: color .2s;
  position: relative
}

.footer .footer-container .footer-bottom .bottom-links a:after {
  content: "";
  position: absolute;
  bottom: -3px;
  left: 0;
  width: 0;
  height: 1px;
  background: #7a9faa;
  transition: width .3s ease
}

.footer .footer-container .footer-bottom .bottom-links a:hover {
  color: #395766
}

.footer .footer-container .footer-bottom .bottom-links a:hover:after {
  width: 100%
}

@media screen and (max-width: 768px) {
  .footer .footer-container .footer-top {
    grid-template-columns: 1fr;
    gap: 2.5rem
  }

  .footer .footer-container .footer-top .footer-about p,
  .footer .footer-container .footer-top .footer-about h2 {
    max-width: 100%
  }

  .footer .footer-container .footer-top .footer-about .social-links {
    justify-content: center;
    margin-top: 1.5rem
  }

  .footer .footer-container .footer-top .footer-nav {
    text-align: center
  }

  .footer .footer-container .footer-top .footer-nav h4:after {
    left: 50%;
    transform: translate(-50%)
  }

  .footer .footer-container .footer-top .footer-nav ul li a:hover {
    transform: none
  }

  .footer .footer-container .footer-bottom {
    flex-direction: column;
    gap: 1.2rem;
    text-align: center
  }

  .footer .footer-container .footer-bottom .copyright {
    margin-bottom: .5rem
  }

  .footer .footer-container .footer-bottom .bottom-links {
    justify-content: center
  }
}

@media screen and (max-width: 480px) {
  .footer {
    padding: 2.5rem 0 1.5rem
  }

  .footer .footer-container .footer-top {
    gap: 2rem
  }

  .footer .footer-container .bottom-links {
    gap: 1rem
  }
}

/*! normalize.css v8.0.1 | MIT License | github.com/necolas/normalize.css */
html {
  line-height: 1.15;
  -webkit-text-size-adjust: 100%
}

body {
  margin: 0
}

main {
  display: block
}

h1 {
  font-size: 2em;
  margin: .67em 0
}

hr {
  box-sizing: content-box;
  height: 0;
  overflow: visible
}

pre {
  font-family: monospace, monospace;
  font-size: 1em
}

a {
  background-color: transparent
}

abbr[title] {
  border-bottom: none;
  text-decoration: underline;
  text-decoration: underline dotted
}

b,
strong {
  font-weight: bolder
}

code,
kbd,
samp {
  font-family: monospace, monospace;
  font-size: 1em
}

small {
  font-size: 80%
}

sub,
sup {
  font-size: 75%;
  line-height: 0;
  position: relative;
  vertical-align: baseline
}

sub {
  bottom: -.25em
}

sup {
  top: -.5em
}

img {
  border-style: none
}

button,
input,
optgroup,
select,
textarea {
  font-family: inherit;
  font-size: 100%;
  line-height: 1.15;
  margin: 0
}

button,
input {
  overflow: visible
}

button,
select {
  text-transform: none
}

button,
[type=button],
[type=reset],
[type=submit] {
  -webkit-appearance: button
}

button::-moz-focus-inner,
[type=button]::-moz-focus-inner,
[type=reset]::-moz-focus-inner,
[type=submit]::-moz-focus-inner {
  border-style: none;
  padding: 0
}

button:-moz-focusring,
[type=button]:-moz-focusring,
[type=reset]:-moz-focusring,
[type=submit]:-moz-focusring {
  outline: 1px dotted ButtonText
}

fieldset {
  padding: .35em .75em .625em
}

legend {
  box-sizing: border-box;
  color: inherit;
  display: table;
  max-width: 100%;
  padding: 0;
  white-space: normal
}

progress {
  vertical-align: baseline
}

textarea {
  overflow: auto
}

[type=checkbox],
[type=radio] {
  box-sizing: border-box;
  padding: 0
}

[type=number]::-webkit-inner-spin-button,
[type=number]::-webkit-outer-spin-button {
  height: auto
}

[type=search] {
  -webkit-appearance: textfield;
  outline-offset: -2px
}

[type=search]::-webkit-search-decoration {
  -webkit-appearance: none
}

::-webkit-file-upload-button {
  -webkit-appearance: button;
  font: inherit
}

details {
  display: block
}

summary {
  display: list-item
}

template {
  display: none
}

[hidden] {
  display: none
}

body,
h1,
h2,
h3,
h4,
ul,
li,
p {
  padding: 0;
  margin: 0
}

.ad-container {
  margin: 10px 0;
  text-align: center
}

ul,
li {
  list-style: none
}

a {
  text-decoration: none
}

img {
  vertical-align: top
}

html {
  font-size: 16px
}

@media screen and (max-width: 768px) {
  html {
    font-size: 14px
  }
}

[v-cloak] {
  display: none !important
}

body {
  font-family: PingFang SC, Microsoft YaHei, sans-serif;
  box-sizing: border-box;
  width: 100%;
  height: 100%
}

body::-webkit-scrollbar {
  width: 4px;
  height: 6px
}

body::-webkit-scrollbar-track {
  background: #333;
  border-radius: 2px
}

body::-webkit-scrollbar-thumb {
  background: #666;
  border-radius: 10px
}

body::-webkit-scrollbar-thumb:hover {
  background: #999
}

body #app {
  display: flex;
  flex-direction: column;
  width: 100%;
  height: 100vh;
  box-sizing: border-box;
  background: #f2f7fa;
  overflow-y: auto
}

body #app::-webkit-scrollbar {
  display: none
}

.chat-assistant {
  position: fixed;
  right: 30px;
  bottom: 30px;
  z-index: 999;
  display: flex;
  flex-direction: column;
  align-items: flex-end
}

.chat-assistant .chat-button {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: linear-gradient(135deg, #d4e2e9, #90b8c9);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 24px;
  box-shadow: 0 4px 20px #2d426340;
  cursor: pointer;
  position: relative;
  transition: all .3s cubic-bezier(.175, .885, .32, 1.275);
  z-index: 2;
  border: 2px solid rgba(255, 255, 255, .2)
}

.chat-assistant .chat-button:hover {
  transform: scale(1.05) translateY(-5px);
  box-shadow: 0 6px 25px #2d42634d
}

.chat-assistant .chat-button .pulse-ring {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  animation: pulse 2s infinite;
  background: #d4e2e9;
  opacity: 0;
  z-index: -1
}

.chat-assistant .chat-message {
  background: #fff;
  padding: 15px 20px;
  border-radius: 12px;
  box-shadow: 0 5px 25px #0000001a;
  margin-bottom: 15px;
  max-width: 300px;
  position: relative;
  animation: fadeInUp .5s ease-out;
  border-left: 4px solid #d4e2e9
}

.chat-assistant .chat-message p {
  color: #5d656b;
  font-size: .95rem;
  line-height: 1.5;
  margin: 0 0 5px
}

.chat-assistant .chat-message .chat-message-close {
  position: absolute;
  top: 8px;
  right: 8px;
  background: none;
  border: none;
  color: #5d656b;
  font-size: .8rem;
  cursor: pointer;
  padding: 2px;
  opacity: .7
}

.chat-assistant .chat-message .chat-message-close:hover {
  opacity: 1
}

.chat-assistant .chat-message .chat-message-arrow {
  position: absolute;
  bottom: -8px;
  right: 20px;
  width: 16px;
  height: 16px;
  background: #fff;
  transform: rotate(45deg);
  box-shadow: 4px 4px 8px #0000000d
}

.chat-assistant .chat-message.hidden {
  display: none
}

@keyframes pulse {
  0% {
    transform: scale(.95);
    opacity: .7
  }

  50% {
    transform: scale(1.3);
    opacity: 0
  }

  to {
    transform: scale(.95);
    opacity: 0
  }
}

@keyframes fadeInUp {
  0% {
    opacity: 0;
    transform: translateY(20px)
  }

  to {
    opacity: 1;
    transform: translateY(0)
  }
}

@media screen and (max-width: 768px) {
  .chat-assistant {
    right: 20px;
    bottom: 20px
  }

  .chat-assistant .chat-button {
    width: 50px;
    height: 50px;
    font-size: 20px
  }

  .chat-assistant .chat-message {
    max-width: 250px;
    padding: 12px 15px
  }

  .chat-assistant .chat-message p {
    font-size: .85rem
  }
}

.video-list-content {
  flex: 1;
  padding: 2rem 0;
  background: #f2f7fa
}

.video-list-content .page-intro {
  max-width: 1400px;
  margin: 0 auto 3rem;
  padding: 0 1.5rem;
  text-align: center
}

.video-list-content .page-intro h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem
}

.video-list-content .page-intro p {
  font-size: 1.1rem;
  color: #5d656b;
  max-width: 800px;
  margin: 0 auto;
  line-height: 1.6
}

.video-list-content .page-intro .intro-stats {
  display: flex;
  justify-content: center;
  gap: 3rem;
  margin-top: 2rem
}

.video-list-content .page-intro .intro-stats .stat-item {
  text-align: center
}

.video-list-content .page-intro .intro-stats .stat-item .stat-number {
  font-size: 2rem;
  font-weight: 700;
  color: #90b8c9
}

.video-list-content .page-intro .intro-stats .stat-item .stat-label {
  font-size: .9rem;
  color: #5d656b
}

.video-list-content .filter-section {
  max-width: 1400px;
  margin: 0 auto 2rem;
  padding: 0 1.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
  box-sizing: border-box
}

.video-list-content .filter-section .search-box {
  flex: 1;
  min-width: 250px;
  position: relative
}

.video-list-content .filter-section .search-box input {
  box-sizing: border-box;
  width: 100%;
  padding: .8rem 1rem .8rem 2.5rem;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 1rem;
  background: #fff
}

.video-list-content .filter-section .search-box input:focus {
  outline: none;
  border-color: #d4e2e9
}

.video-list-content .filter-section .search-box svg {
  position: absolute;
  left: .8rem;
  top: 50%;
  transform: translateY(-50%);
  width: 1.2rem;
  height: 1.2rem;
  fill: #5d656b
}

.video-list-content .filter-section .tag-filter {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem
}

.video-list-content .filter-section .tag-filter .tag {
  padding: .5rem 1rem;
  background: #e9f0f4;
  border-radius: 20px;
  font-size: .9rem;
  color: #90b8c9;
  cursor: pointer;
  transition: all .3s ease;
  font-weight: 550
}

.video-list-content .filter-section .tag-filter .tag:hover,
.video-list-content .filter-section .tag-filter .tag.active {
  background: #aecbd4;
  color: #fff
}

.video-list-content .videos-section {
  max-width: 1400px;
  margin: 0 auto 4rem;
  padding: 0 1.5rem
}

.video-list-content .videos-section h2 {
  font-size: 1.8rem;
  margin-bottom: 2rem;
  position: relative
}

.video-list-content .videos-section h2:after {
  content: "";
  position: absolute;
  bottom: -10px;
  left: 0;
  width: 60px;
  height: 4px;
  background: #7a9faa;
  border-radius: 2px
}

.video-list-content .videos-section .videos-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 2rem
}

.video-list-content .videos-section .videos-grid .video-card {
  background: #fff;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 12px #0000000d;
  transition: transform .3s ease, box-shadow .3s ease
}

.video-list-content .videos-section .videos-grid .video-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 24px #0000001a
}

.video-list-content .videos-section .videos-grid .video-card .card-img {
  height: 200px;
  position: relative;
  overflow: hidden
}

.video-list-content .videos-section .videos-grid .video-card .card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover
}

.video-list-content .videos-section .videos-grid .video-card .card-img .duration {
  position: absolute;
  bottom: 10px;
  right: 10px;
  background: #000000b3;
  color: #fff;
  padding: .2rem .6rem;
  border-radius: 4px;
  font-size: .8rem
}

.video-list-content .videos-section .videos-grid .video-card .card-img .play-icon {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 50px;
  height: 50px;
  background: #a8a0a080;
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center
}

.video-list-content .videos-section .videos-grid .video-card .card-img .play-icon:before {
  content: "";
  border-style: solid;
  border-width: 10px 0 10px 16px;
  border-color: transparent transparent transparent white;
  margin-left: 4px
}

.video-list-content .videos-section .videos-grid .video-card .card-content {
  padding: 1.5rem
}

.video-list-content .videos-section .videos-grid .video-card .card-content .card-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
  font-size: .85rem;
  color: #5d656b
}

.video-list-content .videos-section .videos-grid .video-card .card-content .card-meta .author {
  display: flex;
  align-items: center;
  gap: .5rem
}

.video-list-content .videos-section .videos-grid .video-card .card-content .card-meta .author .author-avatar {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: #d4e2e9;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: .7rem;
  font-weight: 700
}

.video-list-content .videos-section .videos-grid .video-card .card-content h3 {
  font-size: 1.3rem;
  margin-bottom: .8rem;
  line-height: 1.4;
  color: #5d656b;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden
}

.video-list-content .videos-section .videos-grid .video-card .card-content p {
  color: #5d656b;
  font-size: .95rem;
  line-height: 1.6;
  margin-bottom: 1.5rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden
}

.video-list-content .videos-section .videos-grid .video-card .card-content .tags {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem
}

.video-list-content .videos-section .videos-grid .video-card .card-content .tags .tag {
  padding: .2rem .6rem;
  background: #e9f0f4;
  border-radius: 4px;
  font-size: .7rem;
  color: #90b8c9
}

.video-list-content .pagination {
  max-width: 1400px;
  margin: 3rem auto 0;
  padding: 0 1.5rem;
  display: flex;
  justify-content: center;
  gap: .5rem
}

.video-list-content .pagination .page-item {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  background: #fff;
  color: #90b8c9;
  cursor: pointer;
  transition: all .3s ease
}

.video-list-content .pagination .page-item:hover {
  background: #e9f0f4
}

.video-list-content .pagination .page-item.active {
  background: #90b8c9;
  color: #fff
}

.video-list-content .pagination .page-item.disabled {
  opacity: .5;
  cursor: not-allowed
}

@media screen and (max-width: 768px) {
  .video-list-content {
    padding: 1.5rem 0
  }

  .video-list-content .page-intro {
    margin-bottom: 2rem
  }

  .video-list-content .page-intro h1 {
    font-size: 2rem
  }

  .video-list-content .page-intro .intro-stats {
    gap: 1.5rem
  }

  .video-list-content .filter-section {
    flex-direction: column;
    align-items: stretch
  }

  .video-list-content .filter-section .search-box {
    width: 100%
  }

  .video-list-content .filter-section .tag-filter {
    width: 100%;
    flex-wrap: nowrap;
    overflow-x: auto;
    scrollbar-width: none;
    -ms-overflow-style: none
  }

  .video-list-content .filter-section .tag-filter::-webkit-scrollbar {
    display: none
  }

  .video-list-content .filter-section .tag-filter .tag {
    width: auto;
    white-space: nowrap
  }

  .video-list-content .videos-section .videos-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem
  }
}

.skeleton-card {
  background: #fff;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 12px #0000000d
}

.skeleton-card .skeleton {
  background: linear-gradient(90deg, #f0f6f9 25%, #e0edf2 37%, #f0f6f9 63%);
  background-size: 400% 100%;
  animation: skeleton-loading 1.4s ease infinite
}

.skeleton-card .skeleton-image {
  width: 100%;
  height: 200px
}

.skeleton-card .skeleton-content {
  padding: 1.5rem
}

.skeleton-card .skeleton-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem
}

.skeleton-card .skeleton-meta .skeleton-author {
  display: flex;
  align-items: center;
  gap: .5rem
}

.skeleton-card .skeleton-meta .skeleton-author .skeleton-avatar {
  width: 24px;
  height: 24px;
  border-radius: 50%
}

.skeleton-card .skeleton-meta .skeleton-author .skeleton-name {
  width: 100px;
  height: 16px;
  border-radius: 4px
}

.skeleton-card .skeleton-meta .skeleton-date {
  width: 80px;
  height: 16px;
  border-radius: 4px
}

.skeleton-card .skeleton-title {
  height: 24px;
  margin-bottom: 1rem;
  border-radius: 4px
}

.skeleton-card .skeleton-excerpt {
  height: 16px;
  margin-bottom: 1rem;
  border-radius: 4px
}

.skeleton-card .skeleton-tags {
  display: flex;
  gap: .5rem
}

.skeleton-card .skeleton-tags .skeleton-tag {
  width: 60px;
  height: 20px;
  border-radius: 4px
}

@keyframes skeleton-loading {
  0% {
    background-position: 100% 50%
  }

  to {
    background-position: 0 50%
  }
}