:root { font-family: "Segoe UI", "Microsoft YaHei", sans-serif; color: #234571; background: #fcfdff; font-synthesis: none; }
* { box-sizing: border-box; letter-spacing: 0; }
body { margin: 0; min-width: 0; }
a { color: inherit; text-underline-offset: 4px; }
button { font: inherit; cursor: pointer; }
:focus-visible { outline: 3px solid #d5a520; outline-offset: 4px; }
html[data-language="zh"] [data-copy="en"], html[data-language="en"] [data-copy="zh"] { display: none; }
.info-header { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 14px max(20px, calc((100% - 1040px) / 2)); background: #2c4f7b; color: white; }
.info-brand { display: flex; align-items: center; gap: 10px; font-size: 20px; font-weight: 700; text-decoration: none; }
.info-brand img { width: 44px; height: 44px; }
.info-language { display: flex; padding: 3px; border: 1px solid #82a7d0; border-radius: 30px; flex-shrink: 0; }
.info-language button { border: 0; border-radius: 30px; color: white; background: none; min-height: 36px; min-width: 40px; }
.info-language [aria-pressed="true"] { background: #3971af; }
.info-nav { display: flex; justify-content: center; gap: 24px; padding: 0 16px; flex-wrap: wrap; border-bottom: 1px solid #d8e4f1; }
.info-nav a { min-height: 48px; padding: 14px 0; text-decoration: none; border-bottom: 3px solid transparent; }
.info-nav [aria-current] { border-color: #d5a520; font-weight: 700; }
.info-nav a:hover, .info-footer a:hover { color: #285b91; text-decoration: underline; }
.info-main { max-width: 1040px; margin: 0 auto; padding: 32px 24px 48px; }
.info-heading { margin-bottom: 32px; border-bottom: 1px solid #d8e4f1; padding-bottom: 24px; }
h1 { font-size: 32px; margin: 18px 0 12px; }
h2 { font-size: 21px; margin: 0 0 14px; }
p { line-height: 1.85; margin: 10px 0; }
.updated, .translation { color: #5b6d82; font-size: 14px; }
.info-section { max-width: 780px; margin-top: 32px; }
.contact-links { display: flex; gap: 24px; flex-wrap: wrap; margin-top: 20px; }
.contact-links a { padding-block: 8px; }
.info-footer { padding: 24px; border-top: 1px solid #d8e4f1; text-align: center; color: #5b6d82; font-size: 14px; }
.info-footer nav { display: flex; justify-content: center; gap: 20px; flex-wrap: wrap; }
.info-footer a { padding-block: 10px; }
.lead { margin-bottom: 32px; color: #5b6d82; }
.notebook-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 28px; }
.notebook-entry { display: flex; gap: 18px; align-items: center; border-bottom: 1px solid #d8e4f1; padding-bottom: 24px; min-width: 0; }
.notebook-entry img { width: 120px; height: 120px; object-fit: contain; flex-shrink: 0; }
.notebook-entry h3 { margin: 4px 0; font-size: 19px; overflow-wrap: anywhere; }
.notebook-entry p { font-size: 14px; margin: 5px 0; }
.category { color: #358555; }
.notebook-intro, .article-contents { max-width: 780px; border-left: 3px solid #d5a520; padding-left: 20px; margin-bottom: 28px; }
.guide-list { max-width: 780px; }
.guide-list article { border-bottom: 1px solid #d8e4f1; padding: 24px 0; }
.guide-list h2 { margin-bottom: 8px; }
.guide-list a, .contact-links a { overflow-wrap: anywhere; }
.guide-specimens { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); max-width: 780px; gap: 16px; margin-top: 28px; }
.guide-specimens figure { margin: 0; text-align: center; min-width: 0; }
.guide-specimens img { display: block; width: 100%; max-width: 144px; height: 144px; object-fit: contain; margin: auto; }
.guide-specimens figcaption { font-size: 14px; overflow-wrap: anywhere; }
.learning-article { max-width: 780px; }
.article-contents { display: flex; flex-direction: column; gap: 12px; margin-top: 28px; }
.article-contents a { padding: 5px 0; }
.editor-note { color: #5b6d82; font-size: 14px; }
.info-section li { line-height: 1.85; padding-block: 6px; }
.practice-question { padding: 20px; background: #f0f5fb; border-left: 3px solid #3971af; }
summary { cursor: pointer; padding: 12px 0; font-weight: 600; }
.category-links { display: flex; flex-wrap: wrap; gap: 12px 24px; margin: 28px 0; }
.category-links a { padding: 8px 0; }
.notebook-category { margin-top: 36px; scroll-margin-top: 20px; }
.notebook-entry { scroll-margin-top: 20px; }
.sources a { overflow-wrap: anywhere; }
@media (max-width: 700px) {
  .info-header { padding: 12px 16px; }
  .info-brand { font-size: 17px; }
  .info-brand img { width: 36px; height: 36px; }
  .info-nav { gap: 18px; font-size: 14px; }
  .info-main { padding: 24px 16px 40px; }
  h1 { font-size: 28px; }
  h2 { font-size: 20px; }
  .notebook-grid { grid-template-columns: 1fr; }
  .notebook-entry { gap: 14px; }
  .notebook-entry img { width: 88px; height: 88px; }
}