:root{--white:#fff;--ink:#111;--charcoal:#262626;--gray:#6b6b6b;--light:#f5f5f2;--border:#e4e4df;--green:#355e4a;--dark-green:#244437;--light-green:#e8f0eb;--sun:#d9aa4e;--radius:24px}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;color:var(--ink);background:var(--white);font-family:"Noto Sans SC","Source Han Sans SC","Microsoft YaHei",sans-serif;line-height:1.7}a{color:inherit}.container{width:min(1200px,calc(100% - 48px));margin:auto}.learn-header{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.94);border-bottom:1px solid var(--border);backdrop-filter:blur(18px)}.learn-nav{min-height:82px;display:flex;align-items:center;gap:28px}.learn-brand{display:flex;align-items:center;gap:12px;text-decoration:none;margin-right:auto}.learn-brand img{width:48px;height:48px;border-radius:50%;object-fit:cover}.learn-brand strong{display:block;font:800 20px/1.2 Inter,Arial,sans-serif}.learn-brand small{display:block;color:var(--gray);font-size:12px}.learn-links{display:flex;align-items:center;gap:26px}.learn-links a{text-decoration:none;font-weight:600}.learn-links a:hover{color:var(--green)}.language-select{height:44px;border:1px solid var(--border);background:#fff;border-radius:12px;padding:0 34px 0 14px;font:inherit}.menu-toggle{display:none;width:44px;height:44px;border:1px solid var(--border);border-radius:12px;background:#fff;font-size:20px}.learn-hero{padding:110px 0 76px;background:linear-gradient(180deg,#f8faf8 0,#fff 100%)}.kicker{color:var(--green);font:800 13px/1.3 Inter,Arial,sans-serif;letter-spacing:.16em;text-transform:uppercase}.learn-hero h1{max-width:800px;margin:18px 0 24px;font-size:clamp(46px,7vw,76px);line-height:1.06;letter-spacing:-.045em}.learn-hero p{max-width:720px;margin:0;color:var(--gray);font-size:20px}.category-section,.articles-section{padding:70px 0}.section-head{max-width:760px;margin-bottom:36px}.section-head h2{font-size:clamp(32px,5vw,48px);line-height:1.15;letter-spacing:-.035em;margin:0 0 14px}.section-head p{color:var(--gray);font-size:18px;margin:0}.category-list{display:flex;flex-wrap:wrap;gap:12px}.category-button{min-height:48px;padding:10px 18px;border:1px solid var(--border);border-radius:999px;background:#fff;color:var(--charcoal);font:700 15px/1.2 inherit;cursor:pointer}.category-button:hover,.category-button[aria-pressed="true"]{background:var(--dark-green);border-color:var(--dark-green);color:#fff}.articles-section{background:var(--light)}.article-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}.article-card{display:flex;flex-direction:column;overflow:hidden;background:#fff;border:1px solid var(--border);border-radius:var(--radius);min-width:0}.article-card[hidden]{display:none}.article-cover{aspect-ratio:16/10;display:grid;place-items:center;position:relative;overflow:hidden;background:linear-gradient(145deg,var(--light-green),#d5e2da);font-size:64px}.article-cover::after{content:"";position:absolute;width:160px;height:160px;border:1px solid rgba(53,94,74,.18);border-radius:50%;right:-42px;bottom:-70px}.article-card:nth-child(2n) .article-cover{background:linear-gradient(145deg,#f6f0e2,#e9dec4)}.article-card-body{display:flex;flex:1;flex-direction:column;padding:28px}.article-category{color:var(--green);font-size:13px;font-weight:800}.article-card h2{font-size:24px;line-height:1.35;margin:10px 0 14px}.article-card p{color:var(--gray);margin:0 0 22px}.read-more{margin-top:auto;color:var(--green);font-weight:800;text-decoration:none}.read-more:hover{text-decoration:underline}.empty-state{display:none;padding:30px;border:1px dashed var(--border);border-radius:18px;color:var(--gray)}.learn-footer{padding:46px 0;background:#122019;color:#dce6e0}.learn-footer-inner{display:flex;align-items:center;justify-content:space-between;gap:24px}.learn-footer p{margin:0;color:#aebfb5}.article-hero{padding:80px 0 54px;background:var(--light)}.breadcrumbs{font-size:14px;color:var(--gray);margin-bottom:28px}.breadcrumbs a{color:var(--green)}.article-hero h1{max-width:900px;font-size:clamp(38px,6vw,64px);line-height:1.08;letter-spacing:-.04em;margin:0 0 22px}.article-deck{max-width:760px;color:var(--gray);font-size:20px}.article-layout{display:grid;grid-template-columns:minmax(0,760px) 260px;gap:80px;padding:70px 0 100px}.article-content h2{margin:48px 0 14px;font-size:32px;line-height:1.25}.article-content p,.article-content li{font-size:18px;color:#383838}.article-note{padding:22px 24px;border-left:4px solid var(--sun);background:#faf7ef;border-radius:0 16px 16px 0}.article-toc{position:sticky;top:110px;align-self:start;padding:24px;border:1px solid var(--border);border-radius:18px}.article-toc strong{display:block;margin-bottom:10px}.article-toc a{display:block;color:var(--gray);font-size:14px;margin:8px 0}.placeholder-banner{padding:18px 22px;background:var(--light-green);color:var(--dark-green);border-radius:16px;font-weight:700}@media(max-width:900px){.article-grid{grid-template-columns:repeat(2,1fr)}.article-layout{grid-template-columns:1fr}.article-toc{display:none}}@media(max-width:767px){.container{width:min(100% - 32px,1200px)}.learn-nav{min-height:70px}.learn-brand small{display:none}.menu-toggle{display:grid;place-items:center}.learn-links{display:none;position:absolute;left:16px;right:16px;top:68px;padding:14px;background:#fff;border:1px solid var(--border);border-radius:16px;box-shadow:0 16px 40px rgba(0,0,0,.1)}.learn-links.is-open{display:grid}.learn-links a{min-height:44px;display:flex;align-items:center}.learn-hero{padding:72px 0 48px}.learn-hero h1{font-size:44px}.learn-hero p{font-size:17px}.category-section,.articles-section{padding:48px 0}.category-list{display:grid;grid-template-columns:1fr 1fr}.category-button{border-radius:14px}.article-grid{grid-template-columns:1fr}.article-card-body{padding:24px}.learn-footer-inner{display:grid}.article-hero{padding:54px 0 38px}.article-layout{padding:42px 0 70px}.article-content p,.article-content li{font-size:17px}}
.page-language-links{display:flex;align-items:center;gap:8px;font-size:14px;white-space:nowrap}.page-language-links a,.page-language-links span[aria-current]{min-height:44px;display:inline-flex;align-items:center;text-decoration:none}.page-language-links a:hover{color:var(--green)}.page-language-links span[aria-current]{font-weight:800;color:var(--green);box-shadow:inset 0 -2px var(--sun)}
@media(max-width:767px){.learn-brand{order:1}.page-language-links{order:2;margin-left:auto;font-size:13px}.menu-toggle{order:3}.learn-nav{gap:10px}}
@media(max-width:430px){.page-language-links{gap:5px;font-size:12px}.learn-brand img{width:42px;height:42px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}
/* 语言选择：与首页一致的地球图标下拉菜单 */
.language-dropdown {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  color: var(--color-charcoal, #262626);
}

.language-dropdown__icon {
  display: inline-flex;
  width: 20px;
  height: 20px;
  flex: 0 0 20px;
  color: var(--color-green, #355e4a);
}

.language-dropdown__icon svg {
  width: 100%;
  height: 100%;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.65;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.language-dropdown__select {
  min-width: 104px;
  min-height: 44px;
  padding: 0 34px 0 12px;
  border: 1px solid var(--color-border, #e4e4df);
  border-radius: 10px;
  background-color: #fff;
  color: var(--color-charcoal, #262626);
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}

.language-dropdown__select:hover {
  border-color: var(--color-green, #355e4a);
}

.language-dropdown__select:focus-visible {
  outline: 3px solid rgba(217, 170, 78, 0.35);
  outline-offset: 2px;
}

@media (max-width: 767px) {
  .language-dropdown {
    gap: 6px;
  }

  .language-dropdown__select {
    min-width: 96px;
    padding-left: 10px;
  }
}

/* 首页与知识库共用的手机端紧凑菜单视觉 */
@media (max-width: 767px) {
  .learn-header {
    position: relative;
    top: auto;
  }

  .learn-nav {
    gap: 8px;
  }

  .learn-brand {
    min-width: 0;
  }

  .menu-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    width: auto;
    min-width: 74px;
    height: 42px;
    padding: 0 10px;
    border: 1px solid var(--border);
    border-radius: 10px;
    background: #fff;
    color: var(--dark-green);
    font-size: 13px;
    font-weight: 750;
    line-height: 1;
    white-space: nowrap;
  }

  .menu-toggle:hover,
  .menu-toggle[aria-expanded="true"] {
    border-color: #adc1b5;
    background: var(--light-green);
  }

  .menu-toggle .menu-icon {
    font-size: 17px;
    font-weight: 500;
  }

  .learn-links {
    top: calc(100% + 6px);
    left: 16px;
    right: 16px;
    padding: 0 14px;
    overflow: hidden;
    border-radius: 12px;
    background: #fff;
    box-shadow: 0 12px 28px rgba(24, 45, 35, .1);
  }

  .learn-links.is-open {
    display: block;
  }

  .learn-links a {
    min-height: 46px;
    margin: 0;
    padding: 0 2px;
    border-bottom: 1px solid #ecece8;
    font-size: 14px;
  }

  .learn-links a:last-child {
    border-bottom: 0;
  }

  .learn-links a.is-current {
    color: var(--dark-green);
    font-weight: 800;
    box-shadow: inset 3px 0 var(--sun);
    padding-left: 12px;
  }

  .learn-links .mobile-menu-excluded {
    display: none !important;
  }
}

@media (max-width: 360px) {
  .learn-nav {
    gap: 6px;
  }

  .learn-brand {
    gap: 7px;
  }

  .learn-brand img {
    width: 38px;
    height: 38px;
  }

  .learn-brand strong {
    font-size: 16px;
  }

  .language-dropdown {
    gap: 4px;
  }

  .language-dropdown__icon {
    width: 16px;
    height: 16px;
    flex-basis: 16px;
  }

  .language-dropdown__select {
    min-width: 68px;
    min-height: 40px;
    padding: 0 20px 0 6px;
    font-size: 12px;
  }

  .menu-toggle {
    min-width: 70px;
    height: 40px;
    padding-inline: 8px;
    font-size: 12px;
  }
}