@import url("./tokens.css");
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 108px; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 15px/1.75 var(--sans); -webkit-font-smoothing: antialiased; }
button, input { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
button { cursor: pointer; }
a { color: inherit; text-decoration: none; }
button:focus-visible, a:focus-visible, input:focus-visible, summary:focus-visible { outline: 3px solid #799568; outline-offset: 5px; }
button:disabled { cursor: default; }
h1, h2, h3, p { margin: 0; }
[hidden] { display: none !important; }
.container { width: min(var(--page-width), calc(100% - 64px)); margin-inline: auto; }
.skip-link { position: fixed; top: -100px; left: 24px; padding: 12px 20px; background: var(--ink); color: white; z-index: 100; }
.skip-link:focus { top: 12px; }
.site-header { height: 88px; background: rgba(247,248,244,.97); border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 20; }
.header-inner { height: 100%; display: flex; align-items: center; justify-content: space-between; gap: 30px; }
.brand { display: flex; align-items: center; gap: 13px; flex-shrink: 0; }
.brand-mark { width: 36px; height: 36px; display: grid; grid-template-columns: 1fr 1fr; gap: 3px; padding: 9px; border-radius: 9px; background: var(--green); }
.brand-mark i { background: #eaf0e4; border-radius: 1px; }
.brand-name { display: block; font-size: 19px; font-weight: 700; letter-spacing: -.7px; line-height: 1.3; }
.brand-subtitle { display: block; font-size: 10px; color: var(--muted); letter-spacing: 1.3px; margin-top: 2px; }
.header-nav { display: flex; gap: 32px; align-items: center; font-size: 13px; }
.header-nav a { padding-block: 30px; position: relative; }
.header-nav a:hover { color: var(--green); }
.header-nav a.active::after { content: ""; position: absolute; bottom: 20px; left: 0; right: 0; height: 2px; background: var(--green); }
.version { font-size: 11px; color: var(--muted); border: 1px solid var(--line); border-radius: 6px; padding: 5px 10px; white-space: nowrap; }
.version b { color: var(--green); font-family: var(--mono); font-weight: 500; }
.hero { padding: 64px 0 45px; display: grid; grid-template-columns: 1.12fr 1fr; gap: 52px; align-items: center; }
.eyebrow { display: flex; gap: 9px; align-items: center; font: 10px/1.5 var(--mono); letter-spacing: 1.4px; color: var(--green); }
.eyebrow::before { content: ""; width: 6px; height: 6px; background: #779368; border-radius: 50%; flex: 0 0 auto; }
.hero h1 { font-size: clamp(32px, 3.5vw, 46px); line-height: 1.44; letter-spacing: -.7px; margin-top: 19px; font-weight: 650; }
.hero h1 em { color: var(--green); font-style: normal; font-family: var(--serif); font-weight: 600; letter-spacing: 1px; }
.hero-description { max-width: 465px; margin-top: 19px; color: var(--muted); line-height: 1.95; font-size: 14px; }
.hero-actions { display: flex; align-items: center; gap: 26px; margin-top: 25px; }
.button { display: inline-flex; justify-content: center; gap: 26px; align-items: center; min-height: 44px; border: 1px solid transparent; border-radius: 7px; padding: 9px 20px; font-size: 13px; font-weight: 500; background: var(--green); color: #fff; transition: background .18s; }
.button:hover { background: var(--green-dark); }
.button.secondary { background: transparent; color: var(--green); border-color: var(--line-strong); }
.button.secondary:hover { background: var(--green-soft); }
.text-link { font-size: 12px; color: var(--muted); display: inline-flex; align-items: center; gap: 9px; }
.text-link:hover { color: var(--green); }
.architecture { margin: 0; padding: 22px 25px 16px; border: 1px solid var(--line); border-radius: var(--radius); background-color: #f0f3ed; background-image: radial-gradient(#c8d3c3 .7px, transparent .7px); background-size: 16px 16px; }
.diagram-top { display: flex; align-items: center; justify-content: space-between; font: 10px/1.5 var(--mono); color: var(--muted); letter-spacing: 1px; }
.diagram-top span:last-child { padding: 2px 6px; border: 1px solid var(--line-strong); border-radius: 3px; background: #f7f8f4; font-size: 9px; }
.architecture svg { display: block; width: 100%; height: auto; margin: 18px 0 14px; font-family: var(--sans); }
.architecture figcaption { font-size: 10px; color: var(--muted); text-align: center; letter-spacing: .6px; }
.overview { display: flex; gap: 40px; align-items: center; padding: 22px 0; border-block: 1px solid var(--line); }
.overview-stat { display: flex; align-items: baseline; gap: 10px; padding-right: 36px; border-right: 1px solid var(--line); }
.overview-stat strong { font: 25px/1.2 var(--mono); color: var(--green); letter-spacing: -1px; }
.overview-stat span { font-size: 11px; color: var(--muted); white-space: nowrap; }
.overview-note { margin-left: auto; font-size: 11px; color: var(--muted); display: flex; align-items: center; gap: 8px; }
.dot { display: inline-block; width: 6px; height: 6px; border-radius: 50%; background: #99ab89; }
.section { padding-top: 58px; }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 24px; margin-bottom: 26px; }
.section-kicker { display: block; font: 10px/1.4 var(--mono); letter-spacing: 1.8px; color: var(--muted); margin-bottom: 6px; }
.section-heading h2 { font-size: 24px; font-weight: 650; letter-spacing: -.5px; }
.section-heading p { font-size: 12px; color: var(--muted); margin-top: 6px; }
.section-side { color: var(--muted); font-size: 11px; text-align: right; }
.catalog-toolbar { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 18px; align-items: center; margin-bottom: 23px; }
.filters { display: flex; flex-wrap: wrap; gap: 6px; }
.filter { color: var(--muted); font-size: 12px; line-height: 1.5; border: 1px solid transparent; border-radius: 6px; padding: 9px 13px; background: transparent; }
.filter:hover { background: #eaf0e5; }
.filter[aria-pressed="true"] { background: var(--green); color: white; }
.filter .filter-count { margin-left: 7px; font-family: var(--mono); font-size: 10px; opacity: .75; }
.search { display: flex; align-items: center; gap: 9px; min-width: 218px; border: 1px solid var(--line); border-radius: 7px; padding: 7px 12px; background: white; }
.search:focus-within { border-color: var(--green); box-shadow: 0 0 0 2px #e2eadc; }
.search svg { flex-shrink: 0; color: var(--muted); }
.search input { min-width: 0; width: 180px; border: 0; outline: 0; font-size: 12px; background: transparent; color: var(--ink); }
.search input::placeholder { color: #7c877f; }
.search input:focus-visible { outline: none; }
.catalog-meta { display: flex; justify-content: space-between; color: var(--muted); font-size: 11px; margin-bottom: 13px; }
.catalog-meta strong { font-weight: 500; color: var(--green); }
.case-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 22px; }
.case-card { border: 1px solid var(--line); border-radius: var(--radius); background: white; overflow: hidden; transition: border-color .2s, transform .2s, box-shadow .2s; }
.case-card:hover { border-color: #a7bca2; transform: translateY(-3px); box-shadow: 0 8px 25px #24352f08; }
.case-link { display: flex; flex-direction: column; height: 100%; }
.case-link:focus-visible { outline-offset: -4px; border-radius: var(--radius); }
.card-visual { position: relative; height: 170px; background-color: #f0f4ed; background-image: linear-gradient(#d5decc50 1px, transparent 1px), linear-gradient(90deg,#d5decc50 1px,transparent 1px); background-size: 22px 22px; display: flex; align-items: center; justify-content: center; overflow: hidden; border-bottom: 1px solid var(--line); }
.card-visual svg { width: calc(100% - 48px); max-width: 270px; height: 94px; margin-top: 20px; }
.card-visual svg text { font-family: var(--mono); }
.card-visual.storage { background-color: #f0f3f4; background-image: linear-gradient(#ccd9dc50 1px, transparent 1px),linear-gradient(90deg,#ccd9dc50 1px,transparent 1px); }
.card-visual.arithmetic { background-color: #f5f2eb; background-image: linear-gradient(#ddd5c750 1px, transparent 1px),linear-gradient(90deg,#ddd5c750 1px,transparent 1px); }
.card-visual.io { background-color: #f1f0f6; background-image: linear-gradient(#d9d5e350 1px, transparent 1px),linear-gradient(90deg,#d9d5e350 1px,transparent 1px); }
.case-number { position: absolute; top: 15px; left: 18px; font: 10px var(--mono); color: var(--muted); letter-spacing: 1px; }
.status { display: inline-flex; align-items: center; gap: 5px; font-size: 10px; line-height: 1.5; border-radius: 4px; padding: 3px 7px; color: #606b63; background: #ffffffcc; border: 1px solid #d9e0d5; white-space: nowrap; }
.status::before { content: ""; width: 4px; height: 4px; border-radius: 50%; background: #99a391; }
.status.preparing { color: var(--amber); background: #fffaf0; border-color: #e5d9bd; }
.status.preparing::before { background: #b8873c; }
.card-visual .status { position: absolute; right: 16px; top: 13px; }
.card-content { display: flex; flex-direction: column; flex: 1; padding: 20px 21px 16px; }
.card-category { color: var(--muted); font-size: 10px; margin-bottom: 7px; letter-spacing: .6px; }
.card-content h3 { font-size: 18px; line-height: 1.5; font-weight: 600; letter-spacing: -.25px; }
.card-description { color: var(--muted); font-size: 12px; line-height: 1.85; margin-top: 8px; flex: 1; }
.card-bottom { margin-top: 22px; padding-top: 13px; border-top: 1px solid #edf0ea; display: flex; justify-content: space-between; align-items: center; font-size: 10px; color: var(--muted); gap: 8px; }
.card-cta { color: var(--green); display: inline-flex; gap: 7px; align-items: center; white-space: nowrap; }
.empty-state { text-align: center; padding: 56px 24px; border: 1px dashed var(--line-strong); border-radius: var(--radius); background: white; }
.empty-state h3 { font-size: 19px; margin-bottom: 8px; }
.empty-state p { color: var(--muted); font-size: 13px; margin-bottom: 20px; }
.module-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; }
.module-card { padding: 22px 20px 18px; border: 1px solid var(--line); border-radius: 10px; background: #fafbf8; display: block; transition: border-color .2s, background .2s; }
.module-card:hover { background: var(--green-soft); border-color: var(--line-strong); }
.module-top { display: flex; justify-content: space-between; align-items: center; margin-bottom: 22px; color: var(--muted); font: 10px var(--mono); }
.module-top span:first-child { border: 1px solid var(--line-strong); color: var(--green); width: 27px; height: 27px; display: inline-flex; align-items: center; justify-content: center; border-radius: 5px; }
.module-card h3 { font-size: 16px; font-weight: 600; }
.module-card p { font-size: 11px; color: var(--muted); margin-top: 7px; line-height: 1.9; }
.module-bottom { display: flex; justify-content: space-between; align-items: center; margin-top: 22px; font-size: 10px; color: var(--green); }
.about { margin-top: 60px; margin-bottom: 48px; border: 1px solid var(--line); border-radius: var(--radius); padding: 34px 36px; background: #edf1e9; display: grid; grid-template-columns: 1.04fr 1fr; gap: 60px; }
.about h2 { font-size: 23px; margin: 6px 0 14px; font-weight: 600; }
.about p { font-size: 12px; line-height: 1.95; color: #63705f; }
.principles { display: grid; gap: 15px; }
.principle { display: grid; grid-template-columns: 27px 1fr; gap: 9px; }
.principle-number { font: 11px/1.8 var(--mono); color: #829279; margin-top: 2px; }
.principle h3 { font-size: 13px; font-weight: 600; margin-bottom: 3px; }
.principle p { font-size: 11px; }
.site-footer { border-top: 1px solid var(--line); padding: 24px 0 30px; }
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 22px; }
.footer-brand { font-size: 12px; font-weight: 600; }
.footer-brand span { font-weight: 400; font-size: 10px; color: var(--muted); margin-left: 12px; }
.footer-meta { font: 10px var(--mono); color: var(--muted); letter-spacing: .5px; }
.visually-hidden { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.noscript { padding: 12px 18px; border: 1px solid var(--line); background: white; color: var(--muted); margin-block: 20px; font-size: 12px; }
@media (min-width: 1600px) { .container { width: min(1250px, calc(100% - 100px)); } .hero { padding-block: 80px 54px; } }
@media (max-width: 1050px) {
  .hero { gap: 30px; } .hero h1 { font-size: 35px; } .hero-description { font-size: 13px; }
  .catalog-toolbar { align-items: flex-start; } .search { flex: 1; max-width: 280px; } .search input { width: 100%; }
  .filter { padding-inline: 10px; } .overview { gap: 25px; } .overview-stat { padding-right: 25px; }
  .card-content { padding-inline: 17px; } .card-content h3 { font-size: 16px; } .case-grid { gap: 16px; }
}
@media (max-width: 800px) {
  .container { width: calc(100% - 40px); } .site-header { height: 76px; } .header-nav { gap: 20px; } .version { display: none; }
  .hero { gap: 25px; grid-template-columns: 1.05fr 1fr; padding-block: 42px 34px; }
  .hero h1 { font-size: 29px; } .hero-description { font-size: 12px; } .eyebrow { font-size: 8px; letter-spacing: .8px; }
  .architecture { padding-inline: 14px; } .diagram-top { font-size: 8px; } .diagram-top span:last-child { font-size: 7px; }
  .hero-actions { gap: 16px; } .button { padding-inline: 16px; font-size: 12px; } .text-link { font-size: 11px; }
  .overview { gap: 23px; flex-wrap: wrap; } .overview-stat { padding-right: 23px; } .overview-note { margin-left: 0; flex: 1 1 100%; }
  .case-grid { grid-template-columns: repeat(2, minmax(0,1fr)); } .module-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .about { gap: 32px; padding: 30px; } .section { padding-top: 44px; } .catalog-toolbar { gap: 15px; } .search { max-width: none; flex-basis: 100%; }
}
@media (max-width: 580px) {
  html { scroll-padding-top: 113px; } .container { width: calc(100% - 36px); }
  .site-header { height: auto; } .header-inner { flex-wrap: wrap; padding-top: 16px; gap: 8px; }
  .brand-mark { width: 31px; height: 31px; padding: 7px; } .brand-name { font-size: 17px; } .brand-subtitle { font-size: 8px; }
  .header-nav { width: 100%; gap: 27px; font-size: 12px; } .header-nav a { padding-block: 9px 12px; } .header-nav a.active::after { bottom: 0; }
  .hero { grid-template-columns: 1fr; gap: 30px; padding-top: 35px; } .hero h1 { font-size: clamp(27px, 7.7vw, 36px); margin-top: 13px; }
  .hero-description { font-size: 13px; max-width: none; margin-top: 15px; } .eyebrow { font-size: 8px; letter-spacing: 1px; }
  .hero-actions { margin-top: 20px; gap: 24px; } .architecture { padding: 18px 23px 14px; } .architecture svg { max-width: 370px; margin-inline: auto; }
  .diagram-top { font-size: 9px; } .diagram-top span:last-child { font-size: 8px; }
  .overview { gap: 14px; padding-block: 20px; } .overview-stat { flex-direction: column; gap: 3px; padding-right: 18px; flex: 1; } .overview-stat:nth-child(3) { border: 0; padding-right: 0; }
  .overview-stat strong { font-size: 23px; } .overview-stat span { font-size: 10px; } .overview-note { font-size: 10px; }
  .section-heading { gap: 14px; align-items: start; margin-bottom: 20px; } .section-heading h2 { font-size: 22px; } .section-heading p { font-size: 11px; } .section-side { display: none; }
  .filter { font-size: 11px; padding: 7px 10px; } .filters { gap: 4px; } .filter .filter-count { margin-left: 5px; }
  .case-grid { grid-template-columns: 1fr; gap: 20px; } .card-visual { height: 180px; } .card-content { padding: 21px; } .card-content h3 { font-size: 19px; }
  .card-description { font-size: 13px; } .card-category { font-size: 11px; } .card-bottom { margin-top: 20px; font-size: 11px; }
  .catalog-meta { font-size: 10px; } .module-grid { gap: 12px; } .module-card { padding: 17px 14px; } .module-card h3 { font-size: 14px; } .module-top { margin-bottom: 17px; }
  .about { grid-template-columns: 1fr; gap: 26px; padding: 26px 23px; margin-top: 44px; margin-bottom: 32px; } .about h2 { font-size: 22px; }
  .footer-inner { align-items: start; flex-direction: column; gap: 10px; } .footer-brand span { display: block; margin: 4px 0 0; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } *, *::before, *::after { transition: none !important; animation: none !important; } }

.status.live { color: #315c47; background: #edf5e9; border-color: #b9d0ac; }
.status.live::before { background: #61834a; }
/* 教材章节卡片：以小节和学习问题形成清楚的阅读顺序。 */
.chapter-card-art{padding:55px 24px 20px;display:flex;flex-direction:column;gap:12px;color:#315c47}.chapter-card-art>span{font:14px ui-monospace,monospace;opacity:.7}.chapter-card-art strong{font-size:20px;font-weight:500;line-height:1.6;max-width:280px}.chapter-card-art small{font-size:10px;opacity:.7}.card-visual.chapter1{background:#edf2e5}.card-visual.chapter2{background:#edf0f2}.chapter2 .chapter-card-art{color:#435665}.module-grid{grid-template-columns:repeat(2,minmax(0,1fr))}@media(max-width:640px){.module-grid{grid-template-columns:1fr}}