:root {
  --ai-brand-700: #0b4b60;
  --ai-brand-600: #0f5f78;
  --ai-brand-500: #176f8b;
  --ai-link: #075e8c;
  --ai-teal: #147d6f;
  --ai-amber: #b45309;
  --ai-text: #17212b;
  --ai-muted: #52606d;
  --ai-border: #d9e2e8;
  --ai-surface: #ffffff;
  --ai-surface-soft: #f6f8fa;
  --ai-brand-soft: #eaf4f7;
  --ai-teal-soft: #eaf7f3;
  --ai-amber-soft: #fff5e8;
  --ai-radius: 12px;
  --ai-shadow: 0 10px 28px rgba(15, 75, 96, 0.08);
}

body {
  background: var(--ai-surface-soft);
  color: var(--ai-text);
  font-family: "Microsoft YaHei", "PingFang SC", system-ui, -apple-system, sans-serif;
}

a {
  color: var(--ai-link);
}

a:focus-visible,
button:focus-visible,
input:focus-visible {
  outline: 3px solid rgba(23, 111, 139, 0.32);
  outline-offset: 3px;
}

.container {
  max-width: 1380px;
  width: 100%;
}

/* Header */
#header {
  background: var(--ai-surface);
  border-bottom: 1px solid var(--ai-border);
  box-shadow: 0 2px 12px rgba(23, 33, 43, 0.04);
}

#header .header-pc,
#header .header-logo {
  background: var(--ai-surface) !important;
}

#header .header-logo {
  height: 76px;
}

#header .header-logo > .container {
  align-items: center;
  display: flex;
  gap: 22px;
  height: 76px;
  padding: 0 18px;
}

#header .logo {
  flex: 0 0 auto;
  height: auto;
  margin: 0;
  max-width: none;
  padding: 0;
}

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

.ai-brand-lockup img {
  border-radius: 9px;
  display: block;
  height: 44px;
  object-fit: cover;
  width: 44px;
}

.ai-brand-copy {
  display: flex;
  flex-direction: column;
  min-width: 218px;
}

.ai-brand-copy strong {
  color: var(--ai-text);
  font-size: 23px;
  font-weight: 750;
  line-height: 1.2;
}

.ai-brand-copy small {
  color: var(--ai-muted);
  font-size: 12px;
  line-height: 1.5;
  margin-top: 2px;
}

#header .menunav {
  flex: 1 1 auto;
  height: 76px;
  overflow: hidden;
  position: static;
  visibility: visible !important;
}

#header .menunav nav.container {
  height: 76px;
  max-width: none;
  padding: 0;
  width: auto;
}

#header .navul {
  align-items: stretch;
  display: flex;
  gap: 2px;
  height: 76px;
  margin: 0;
}

#header .navul > li {
  display: flex;
  height: 76px;
}

#header .navul > li > a {
  align-items: center;
  border-bottom: 3px solid transparent;
  color: var(--ai-text) !important;
  display: flex;
  font-size: 14px;
  height: 76px;
  padding: 0 10px;
  white-space: nowrap;
}

#header .navul > li.current-menu-item > a,
#header .navul > li > a:hover {
  border-bottom-color: var(--ai-brand-600);
  color: var(--ai-brand-600) !important;
  text-shadow: none;
}

#header form.search {
  align-items: center;
  background: var(--ai-surface);
  border: 1px solid var(--ai-border);
  border-radius: 9px;
  display: flex;
  flex: 0 0 270px;
  height: 42px;
  margin: 0;
  overflow: hidden;
  position: static;
}

#header form.search input {
  background: transparent;
  border: 0;
  color: var(--ai-text);
  flex: 1 1 auto;
  font-size: 14px;
  height: 40px;
  min-width: 0;
  padding: 0 12px;
}

#header form.search button {
  align-items: center;
  background: transparent;
  border: 0;
  color: var(--ai-brand-600);
  display: flex;
  height: 40px;
  justify-content: center;
  width: 42px;
}

/* Homepage */
.ai-editorial-home {
  padding: 26px 0 42px;
}

.ai-editorial-home *,
.ai-editorial-home *::before,
.ai-editorial-home *::after {
  box-sizing: border-box;
}

.ai-editorial-home a {
  text-decoration: none;
}

.ai-home-hero {
  display: grid;
  gap: 22px;
  grid-template-areas:
    "intro intro"
    "feature support";
  grid-template-columns: minmax(0, 2.05fr) minmax(380px, 0.95fr);
  padding: 0;
  width: 100%;
}

.ai-home-intro {
  align-items: stretch;
  border-bottom: 1px solid var(--ai-border);
  display: grid;
  gap: 48px;
  grid-area: intro;
  grid-template-columns: minmax(0, 2.05fr) minmax(380px, 0.95fr);
  padding: 26px 6px 28px;
}

.ai-home-intro-copy,
.ai-home-intro-tools {
  min-width: 0;
}

.ai-home-intro-copy {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 150px;
  padding: 0;
}

.ai-home-intro-tools {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 0;
}

.ai-eyebrow {
  color: var(--ai-teal);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.12em;
  margin-bottom: 10px;
}

.ai-home-intro h1 {
  color: var(--ai-text);
  font-size: clamp(34px, 3vw, 46px);
  font-weight: 780;
  letter-spacing: -0.04em;
  line-height: 1.18;
  margin: 0;
}

.ai-home-lead {
  color: #334250;
  font-size: 16px;
  line-height: 1.9;
  margin: 16px 0 0;
  max-width: 720px;
}

.ai-source-promise {
  align-items: flex-start;
  display: flex;
  gap: 13px;
  margin: 0 0 17px;
  padding: 0;
}

.ai-source-promise > i {
  color: var(--ai-teal);
  font-size: 20px;
  line-height: 1.45;
}

.ai-source-promise p {
  margin: 0;
}

.ai-source-promise strong,
.ai-source-promise span {
  display: block;
}

.ai-source-promise strong {
  color: var(--ai-text);
  font-size: 15px;
  margin-bottom: 5px;
}

.ai-source-promise span {
  color: var(--ai-muted);
  font-size: 13px;
  line-height: 1.7;
}

.ai-home-actions {
  align-items: center;
  display: flex;
  gap: 16px;
  margin-top: 0;
}

.ai-button {
  align-items: center;
  border-radius: 8px;
  display: inline-flex;
  font-size: 15px;
  font-weight: 700;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
}

.ai-button-primary {
  background: var(--ai-brand-600);
  color: #fff !important;
}

.ai-button-primary:hover {
  background: var(--ai-brand-700);
}

.ai-button-link {
  color: var(--ai-link) !important;
  padding-left: 4px;
  padding-right: 4px;
}

.ai-home-meta {
  border-top: 1px solid var(--ai-border);
  color: var(--ai-muted);
  display: flex;
  flex-wrap: wrap;
  font-size: 12px;
  gap: 16px;
  margin-top: 16px;
  padding-top: 12px;
}

.ai-home-meta span {
  align-items: center;
  display: inline-flex;
  gap: 6px;
}

.ai-feature-main,
.ai-feature-small,
.ai-task-finder,
.ai-home-recent,
.ai-home-topics,
.ai-editorial-standard {
  background: var(--ai-surface);
  border: 1px solid var(--ai-border);
  border-radius: var(--ai-radius);
}

.ai-feature-main {
  align-self: start;
  display: flex;
  flex-direction: column;
  grid-area: feature;
  min-width: 0;
  overflow: hidden;
}

.ai-feature-image {
  background: var(--ai-brand-700);
  display: block;
  overflow: hidden;
}

.ai-feature-image img {
  aspect-ratio: 1200 / 675;
  display: block;
  height: auto;
  object-fit: cover;
  transition: transform 180ms ease;
  width: 100%;
}

.ai-feature-main:hover .ai-feature-image img {
  transform: scale(1.015);
}

.ai-feature-body {
  display: flex;
  flex: 0 0 auto;
  flex-direction: column;
  padding: 18px 20px 16px;
}

.ai-badge {
  align-self: flex-start;
  background: var(--ai-teal);
  border-radius: 999px;
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  line-height: 1;
  padding: 6px 9px;
}

.ai-badge-amber {
  background: var(--ai-amber);
}

.ai-feature-body h2,
.ai-feature-small h2 {
  margin: 12px 0 0;
}

.ai-feature-body h2 {
  font-size: 22px;
  line-height: 1.42;
}

.ai-feature-body h2 a,
.ai-feature-small h2 a {
  color: var(--ai-text);
}

.ai-feature-body h2 a:hover,
.ai-feature-small h2 a:hover {
  color: var(--ai-link);
}

.ai-feature-body > p {
  color: var(--ai-muted);
  font-size: 13px;
  line-height: 1.75;
  margin: 10px 0 16px;
}

.ai-card-meta {
  color: var(--ai-muted);
  display: flex;
  font-size: 11px;
  gap: 12px;
  justify-content: space-between;
  margin-top: 2px;
}

.ai-feature-support {
  align-self: stretch;
  display: flex;
  flex-direction: column;
  gap: 12px;
  grid-area: support;
  min-width: 0;
}

.ai-feature-small {
  align-items: center;
  display: grid;
  gap: 14px;
  grid-template-columns: minmax(0, 1fr) 132px;
  min-height: 158px;
  overflow: hidden;
  padding: 14px 16px;
}

.ai-feature-small-copy {
  min-width: 0;
}

.ai-feature-small h2 {
  font-size: 16px;
  line-height: 1.45;
}

.ai-feature-small p {
  color: var(--ai-muted);
  display: -webkit-box;
  font-size: 12px;
  line-height: 1.6;
  margin: 7px 0;
  overflow: hidden;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.ai-card-date {
  color: var(--ai-muted);
  font-size: 11px;
}

.ai-feature-small-image {
  aspect-ratio: 1200 / 675;
  align-self: center;
  background: var(--ai-brand-soft);
  border-radius: 10px;
  display: block;
  overflow: hidden;
  width: 132px;
}

.ai-feature-small-image img {
  aspect-ratio: auto;
  display: block;
  height: 100%;
  object-fit: cover;
  width: 100%;
}

.ai-task-finder {
  background: #f4f9fb;
  display: flex;
  flex: 1 1 auto;
  flex-direction: column;
  padding: 14px 16px 12px;
}

.ai-task-finder h2 {
  align-items: center;
  display: flex;
  font-size: 15px;
  gap: 7px;
  margin: 0 0 9px;
}

.ai-task-finder h2 i {
  color: var(--ai-teal);
}

.ai-task-finder nav {
  display: grid;
  flex: 1 1 auto;
  gap: 5px;
  grid-template-rows: repeat(5, minmax(36px, 1fr));
}

.ai-task-finder nav a {
  align-items: center;
  background: #fff;
  border: 1px solid var(--ai-border);
  border-radius: 6px;
  color: #334250;
  display: flex;
  font-size: 12px;
  justify-content: space-between;
  min-height: 36px;
  padding: 0 9px;
}

.ai-task-finder nav a:hover {
  border-color: #91b8c8;
  color: var(--ai-link);
}

.ai-task-all {
  border-top: 1px solid var(--ai-border);
  display: block;
  font-size: 11px;
  font-weight: 700;
  margin-top: 10px;
  padding-top: 10px;
  text-align: center;
}

.ai-home-section {
  margin-top: 22px;
  padding: 18px;
  width: 100%;
}

.ai-section-heading {
  align-items: center;
  display: flex;
  justify-content: space-between;
  margin-bottom: 16px;
}

.ai-section-heading h2 {
  align-items: center;
  color: var(--ai-text);
  display: flex;
  font-size: 20px;
  gap: 8px;
  margin: 0;
}

.ai-section-heading h2 i {
  color: var(--ai-teal);
}

.ai-section-heading > a {
  font-size: 12px;
  font-weight: 700;
}

.ai-recent-grid {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(6, minmax(0, 1fr));
}

.ai-recent-card {
  border-right: 1px solid var(--ai-border);
  display: flex;
  flex-direction: column;
  min-width: 0;
  padding: 0 13px 0 0;
}

.ai-recent-card:last-child {
  border-right: 0;
  padding-right: 0;
}

.ai-recent-thumb {
  aspect-ratio: 1200 / 675;
  background: var(--ai-brand-soft);
  border-radius: 10px;
  display: block;
  margin-bottom: 10px;
  overflow: hidden;
}

.ai-recent-thumb img {
  aspect-ratio: auto;
  display: block;
  height: 100%;
  object-fit: cover;
  width: 100%;
}

.ai-recent-card h3 {
  font-size: 13px;
  line-height: 1.55;
  margin: 0 0 9px;
}

.ai-recent-card h3 a {
  color: var(--ai-text);
}

.ai-recent-card > span {
  color: var(--ai-muted);
  font-size: 11px;
  line-height: 1.5;
  margin-top: auto;
}

.ai-topic-grid {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.ai-topic-card {
  border: 1px solid var(--ai-border);
  border-radius: 10px;
  display: flex;
  flex-direction: column;
  min-height: 268px;
  padding: 16px;
}

.ai-topic-icon {
  align-items: center;
  background: var(--ai-brand-soft);
  border-radius: 9px;
  color: var(--ai-brand-600);
  display: flex;
  font-size: 23px;
  height: 42px;
  justify-content: center;
  width: 42px;
}

.ai-topic-card:nth-child(2) .ai-topic-icon,
.ai-topic-card:nth-child(5) .ai-topic-icon {
  background: var(--ai-teal-soft);
  color: var(--ai-teal);
}

.ai-topic-card:nth-child(4) .ai-topic-icon {
  background: var(--ai-amber-soft);
  color: var(--ai-amber);
}

.ai-topic-card h3 {
  font-size: 17px;
  margin: 12px 0 6px;
}

.ai-topic-card > p {
  color: var(--ai-muted);
  font-size: 11px;
  line-height: 1.65;
  margin: 0;
}

.ai-topic-card ul {
  border-top: 1px solid var(--ai-border);
  list-style: none;
  margin: 12px 0 10px;
  padding: 10px 0 0;
}

.ai-topic-card li + li {
  margin-top: 7px;
}

.ai-topic-card li a {
  align-items: center;
  color: #334250;
  display: flex;
  font-size: 11px;
  line-height: 1.5;
  min-height: 24px;
  overflow: hidden;
}

.ai-topic-link {
  font-size: 12px;
  font-weight: 700;
  margin-top: auto;
}

.ai-editorial-standard {
  align-items: center;
  display: grid;
  gap: 22px;
  grid-template-columns: 1.2fr 2.4fr 1.25fr;
  margin-top: 16px;
  padding: 16px 18px;
  width: 100%;
}

.ai-standard-copy h2 {
  font-size: 16px;
  margin: 0 0 6px;
}

.ai-standard-copy p,
.ai-standard-correction p {
  color: var(--ai-muted);
  font-size: 13px;
  line-height: 1.7;
  margin: 0;
}

.ai-standard-points {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(3, 1fr);
}

.ai-standard-points > span {
  align-items: center;
  display: grid;
  gap: 2px 8px;
  grid-template-columns: 32px 1fr;
}

.ai-standard-points i {
  color: var(--ai-brand-600);
  font-size: 22px;
  grid-row: span 2;
}

.ai-standard-points strong,
.ai-standard-correction strong {
  font-size: 13px;
}

.ai-standard-points small {
  color: var(--ai-muted);
  font-size: 11px;
  line-height: 1.5;
}

.ai-standard-correction {
  border-left: 1px solid var(--ai-border);
  padding-left: 20px;
}

.ai-standard-correction a {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  margin-top: 5px;
}

footer {
  background: #0d3041;
  color: rgba(255, 255, 255, 0.78);
}

footer .footer {
  padding-bottom: 30px;
  padding-top: 30px;
}

footer a,
footer .copyright {
  color: rgba(255, 255, 255, 0.78) !important;
}

@media (max-width: 1199px) {
  .ai-brand-copy small {
    display: none;
  }

  .ai-brand-copy {
    min-width: 112px;
  }

  #header .navul > li > a {
    padding: 0 7px;
  }

  #header form.search {
    flex-basis: 220px;
  }

  .ai-home-hero {
    grid-template-columns: minmax(0, 1.55fr) minmax(340px, 0.85fr);
  }

  .ai-home-intro {
    grid-template-columns: minmax(0, 1.55fr) minmax(340px, 0.85fr);
  }

  .ai-home-intro h1 {
    font-size: 34px;
  }

  .ai-recent-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    row-gap: 20px;
  }

  .ai-recent-card:nth-child(3) {
    border-right: 0;
  }

  .ai-topic-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 991px) {
  .ai-home-hero {
    grid-template-areas:
      "intro"
      "feature"
      "support";
    grid-template-columns: 1fr;
  }

  .ai-home-intro {
    align-items: start;
    gap: 30px;
    grid-template-columns: 1fr;
  }

  .ai-home-intro-copy {
    min-height: 0;
  }

  .ai-feature-support {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .ai-task-finder {
    grid-column: 1 / -1;
  }

  .ai-task-finder nav {
    grid-template-columns: repeat(2, 1fr);
  }

  .ai-editorial-standard {
    grid-template-columns: 1fr;
  }

  .ai-standard-correction {
    border-left: 0;
    border-top: 1px solid var(--ai-border);
    padding-left: 0;
    padding-top: 12px;
  }
}

@media (max-width: 767px) {
  #header .header-m {
    align-items: center;
    background: var(--ai-surface) !important;
    border-bottom: 1px solid var(--ai-border);
    display: flex !important;
    height: 60px;
    justify-content: space-between;
  }

  #header .header-m .logo {
    height: 42px;
    left: 50%;
    position: absolute;
    top: 9px;
    transform: translateX(-50%);
  }

  #header .header-m .ai-brand-lockup {
    gap: 6px;
  }

  #header .header-m .ai-brand-lockup img {
    border-radius: 7px;
    height: 36px;
    width: 36px;
  }

  #header .header-m .ai-brand-lockup span {
    color: var(--ai-text);
    font-size: 16px;
    font-weight: 750;
    white-space: nowrap;
  }

  #header .mb-navbtn,
  #header .schcart-btn .mb-navbtn {
    color: var(--ai-brand-600) !important;
  }

  .ai-editorial-home {
    padding: 16px 0 28px;
  }

  .ai-home-hero {
    display: flex;
    flex-direction: column;
    gap: 14px;
    overflow: hidden;
    padding: 0 12px;
  }

  .ai-home-hero > * {
    min-width: 0;
    width: 100%;
  }

  .ai-home-intro {
    display: block;
    border-bottom: 0;
    padding: 4px 0 6px;
  }

  .ai-home-intro-copy {
    border-bottom: 1px solid var(--ai-border);
    padding: 18px 4px 22px;
  }

  .ai-home-intro-tools {
    margin-top: 0;
    padding: 22px 4px 8px;
  }

  .ai-eyebrow {
    margin-bottom: 8px;
  }

  .ai-home-intro h1 {
    font-size: 28px;
    letter-spacing: -0.03em;
    overflow-wrap: anywhere;
  }

  .ai-home-lead {
    font-size: 15px;
    line-height: 1.75;
    margin: 14px 0 0;
  }

  .ai-source-promise {
    margin-bottom: 16px;
  }

  .ai-home-actions {
    margin-top: 0;
  }

  .ai-home-meta {
    margin-top: 16px;
  }

  .ai-feature-main {
    order: 2;
  }

  .ai-feature-support {
    display: flex;
    order: 3;
  }

  .ai-feature-small {
    grid-template-columns: minmax(0, 1fr) 96px;
    min-height: 0;
  }

  .ai-feature-small-image {
    width: 96px;
  }

  .ai-task-finder nav {
    grid-template-columns: 1fr;
  }

  .ai-home-section {
    border-left: 0;
    border-radius: 0;
    border-right: 0;
    margin-top: 14px;
    padding: 16px 12px;
  }

  .ai-section-heading {
    align-items: flex-start;
    gap: 12px;
  }

  .ai-section-heading h2 {
    font-size: 18px;
  }

  .ai-recent-grid {
    display: grid;
    gap: 0;
    grid-template-columns: 1fr;
  }

  .ai-recent-card,
  .ai-recent-card:nth-child(3),
  .ai-recent-card:last-child {
    align-items: center;
    border-bottom: 1px solid var(--ai-border);
    border-right: 0;
    display: grid;
    gap: 2px 12px;
    grid-template-columns: 96px 1fr;
    padding: 11px 0;
  }

  .ai-recent-card > span {
    margin-top: 0;
  }

  .ai-recent-card:last-child {
    border-bottom: 0;
  }

  .ai-recent-thumb {
    grid-row: span 2;
    margin: 0;
  }

  .ai-recent-thumb img {
    aspect-ratio: auto;
  }

  .ai-recent-card h3 {
    margin: 0;
  }

  .ai-topic-grid {
    grid-template-columns: 1fr;
  }

  .ai-topic-card {
    min-height: 0;
  }

  .ai-editorial-standard {
    border-left: 0;
    border-radius: 0;
    border-right: 0;
    margin-top: 14px;
    padding: 16px 12px;
  }

  .ai-standard-points {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  .ai-feature-image img {
    transition: none;
  }
}