:root {
  --bg: #ffffff;
  --bg-soft: #f6f7fb;
  --bg-tint: #f0f2ff;
  --text: #171a2b;
  --muted: #697087;
  --line: #e7e9f1;
  --primary: #5865e8;
  --primary-dark: #3f4bc6;
  --primary-soft: #eef0ff;
  --csharp: #7654cc;
  --csharp-soft: #f1edfc;
  --vue: #168b67;
  --vue-soft: #e9f8f2;
  --video: #df4661;
  --shadow: 0 18px 50px rgba(35, 41, 80, 0.08);
  --radius-lg: 28px;
  --radius-md: 18px;
  --container: 1160px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
button, input { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
a { color: inherit; }
.container { width: min(calc(100% - 40px), var(--container)); margin-inline: auto; }
.section { padding: 100px 0; scroll-margin-top: 82px; }
.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;
}
.skip-link {
  position: fixed; z-index: 1000; left: 20px; top: 10px; transform: translateY(-150%);
  padding: 10px 16px; border-radius: 10px; color: #fff; background: var(--primary); text-decoration: none;
}
.skip-link:focus { transform: translateY(0); }
:focus-visible { outline: 3px solid rgba(88, 101, 232, 0.4); outline-offset: 3px; }

.site-header {
  position: sticky; z-index: 100; top: 0; height: 76px; border-bottom: 1px solid rgba(231, 233, 241, 0.8);
  background: rgba(255, 255, 255, 0.88); backdrop-filter: blur(18px);
}
.header-inner { height: 100%; display: flex; align-items: center; justify-content: space-between; }
.brand { display: inline-flex; height: 64px; align-items: center; text-decoration: none; }
.brand-logo { display: block; width: 180px; height: 60px; object-fit: contain; }
.site-nav { display: flex; align-items: center; gap: 8px; }
.site-nav a {
  padding: 9px 14px; border-radius: 10px; color: #555d75; text-decoration: none; font-size: 14px; font-weight: 650;
}
.site-nav a:hover { color: var(--primary); background: var(--primary-soft); }
.menu-toggle { display: none; width: 42px; height: 42px; padding: 10px; border: 0; border-radius: 11px; background: var(--bg-soft); cursor: pointer; }
.menu-toggle span { display: block; width: 21px; height: 2px; margin: 4px 0; border-radius: 2px; background: var(--text); transition: 0.2s ease; }

.hero { position: relative; overflow: clip; min-height: 610px; padding: 112px 0 95px; background: linear-gradient(180deg, #fff 0%, #fafaff 100%); }
.hero::before {
  content: ""; position: absolute; inset: 0; opacity: 0.35; pointer-events: none;
  background-image: linear-gradient(rgba(88, 101, 232, 0.07) 1px, transparent 1px), linear-gradient(90deg, rgba(88, 101, 232, 0.07) 1px, transparent 1px);
  background-size: 48px 48px; mask-image: linear-gradient(to bottom, #000, transparent 82%);
}
.hero-glow { position: absolute; border-radius: 999px; filter: blur(1px); opacity: 0.65; pointer-events: none; }
.hero-glow-one { width: 360px; height: 360px; top: -190px; left: 8%; background: radial-gradient(circle, #e4e7ff, rgba(228,231,255,0)); }
.hero-glow-two { width: 520px; height: 520px; right: -220px; bottom: -270px; background: radial-gradient(circle, #e7faf4, rgba(231,250,244,0)); }
.hero-inner { position: relative; z-index: 1; text-align: center; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 9px; padding: 7px 13px; border: 1px solid #dfe2fb;
  border-radius: 999px; color: var(--primary-dark); background: rgba(244, 245, 255, 0.85); font-size: 12px; font-weight: 750; letter-spacing: 0.06em;
}
.eyebrow span { width: 7px; height: 7px; border-radius: 50%; background: var(--primary); box-shadow: 0 0 0 4px rgba(88,101,232,0.12); }
.hero h1 { max-width: 880px; margin: 26px auto 22px; font-size: clamp(42px, 6vw, 74px); line-height: 1.13; letter-spacing: -0.045em; }
.hero h1 em { color: var(--primary); font-style: normal; }
.hero-lead { max-width: 690px; margin: 0 auto; color: var(--muted); font-size: 18px; }
.search-panel {
  display: flex; gap: 10px; max-width: 720px; margin: 38px auto 0; padding: 8px; border: 1px solid var(--line);
  border-radius: 19px; background: #fff; box-shadow: 0 18px 60px rgba(37, 44, 91, 0.12);
}
.search-box { display: flex; flex: 1; align-items: center; gap: 12px; padding: 0 9px; }
.search-icon { position: relative; width: 18px; height: 18px; flex: 0 0 auto; border: 2px solid #8a91a7; border-radius: 50%; }
.search-icon::after { content: ""; position: absolute; width: 7px; height: 2px; right: -5px; bottom: -2px; rotate: 45deg; border-radius: 2px; background: #8a91a7; }
.search-box input { min-width: 0; flex: 1; height: 48px; border: 0; outline: 0; color: var(--text); background: transparent; }
.search-box input::placeholder { color: #9ba1b4; }
.search-box kbd { padding: 2px 8px; border: 1px solid #dcdfea; border-radius: 7px; color: #9096a9; background: #f7f8fb; box-shadow: 0 1px 0 #dcdfea; font-size: 12px; }
.search-button { padding: 0 24px; border: 0; border-radius: 13px; color: #fff; background: var(--primary); font-weight: 750; cursor: pointer; }
.search-button:hover { background: var(--primary-dark); }
.hero-meta { display: flex; align-items: center; justify-content: center; gap: 0; margin-top: 28px; color: #777e92; font-size: 13px; }
.hero-meta span { padding: 0 22px; }
.hero-meta span + span { border-left: 1px solid var(--line); }
.hero-meta strong { margin-right: 4px; color: var(--text); }

.articles-section { background: var(--bg); }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 30px; margin-bottom: 20px; }
.section-kicker { margin: 0 0 8px; color: var(--primary); font-size: 11px; font-weight: 850; letter-spacing: 0.16em; }
.section-heading h2, .about-copy h2 { margin: 0; font-size: clamp(31px, 4vw, 46px); line-height: 1.2; letter-spacing: -0.035em; }
.section-heading > div > p:last-child { margin: 12px 0 0; color: var(--muted); }
.filter-group { display: flex; flex: 0 0 auto; gap: 5px; padding: 5px; border-radius: 14px; background: var(--bg-soft); }
.filter-button { padding: 9px 16px; border: 0; border-radius: 10px; color: var(--muted); background: transparent; font-size: 13px; font-weight: 700; cursor: pointer; }
.filter-button:hover { color: var(--text); }
.filter-button.is-active { color: var(--primary-dark); background: #fff; box-shadow: 0 4px 14px rgba(43, 48, 85, 0.08); }
.results-status { min-height: 24px; margin: 0 0 18px; color: #8b91a3; font-size: 12px; }
.article-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.article-card {
  position: relative; display: flex; min-height: 395px; flex-direction: column; overflow: hidden;
  padding: 26px; border: 1px solid var(--line); border-radius: var(--radius-md); background: #fff;
  transition: transform 0.22s ease, border-color 0.22s ease, box-shadow 0.22s ease;
}
.article-card:hover { transform: translateY(-5px); border-color: #d8dbeb; box-shadow: var(--shadow); }
.article-card[hidden] { display: none; }
.article-card.featured { grid-column: span 2; background: linear-gradient(135deg, #fafaff 0%, #f3f5ff 100%); }
.article-card.featured::after { content: "#"; position: absolute; right: 30px; bottom: -55px; color: rgba(88,101,232,0.07); font-size: 230px; font-weight: 900; line-height: 1; }
.card-topline { position: relative; z-index: 1; display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.topic-badge { padding: 5px 10px; border-radius: 8px; font-size: 11px; font-weight: 800; }
.topic-csharp { color: var(--csharp); background: var(--csharp-soft); }
.topic-vue { color: var(--vue); background: var(--vue-soft); }
.source-label { color: #9298aa; font-size: 11px; font-weight: 650; }
.card-symbol {
  position: relative; z-index: 1; display: grid; place-items: center; width: 54px; height: 54px; margin-top: 32px;
  border-radius: 16px; color: #fff; font-size: 16px; font-weight: 850; box-shadow: 0 10px 26px rgba(37, 42, 74, 0.14);
}
.symbol-csharp { background: linear-gradient(145deg, #8b6add, #6242b7); }
.symbol-vue { background: linear-gradient(145deg, #35b88c, #13805e); }
.symbol-video { background: linear-gradient(145deg, #f06e83, #cc3651); font-size: 14px; }
.symbol-ts { background: linear-gradient(145deg, #5b9fe7, #377ec5); }
.article-card h3 { position: relative; z-index: 1; margin: 22px 0 10px; font-size: 20px; line-height: 1.42; letter-spacing: -0.015em; }
.article-card h3 a { text-decoration: none; }
.article-card h3 a::after { content: ""; position: absolute; inset: 0; }
.article-card > p { position: relative; z-index: 1; margin: 0; color: var(--muted); font-size: 14px; }
.card-tags { position: relative; z-index: 1; display: flex; flex-wrap: wrap; gap: 7px; margin: 18px 0; }
.card-tags span { padding: 4px 9px; border: 1px solid var(--line); border-radius: 999px; color: #777e91; background: rgba(255,255,255,0.75); font-size: 10px; }
.card-link { position: relative; z-index: 2; align-self: flex-start; margin-top: auto; color: var(--primary-dark); font-size: 13px; font-weight: 800; text-decoration: none; }
.card-link span { display: inline-block; margin-left: 4px; transition: transform 0.2s ease; }
.card-link:hover span { transform: translate(2px, -2px); }
.empty-state { padding: 60px 20px; border: 1px dashed #d9dceb; border-radius: var(--radius-md); text-align: center; background: var(--bg-soft); }
.empty-state > span { color: #a5aabd; font-size: 34px; font-weight: 800; }
.empty-state h3 { margin: 10px 0 4px; }
.empty-state p { margin: 0 0 18px; color: var(--muted); }
.empty-state button { padding: 9px 16px; border: 1px solid var(--line); border-radius: 10px; color: var(--primary-dark); background: #fff; font-weight: 700; cursor: pointer; }

.roadmap-section { background: var(--bg-soft); }
.roadmap-heading { margin-bottom: 42px; }
.roadmap-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.roadmap-card { padding: 36px; border: 1px solid var(--line); border-radius: var(--radius-lg); background: #fff; box-shadow: 0 12px 40px rgba(35, 41, 80, 0.04); }
.roadmap-title-row { display: flex; align-items: center; gap: 18px; }
.route-number { display: grid; place-items: center; width: 52px; height: 52px; border-radius: 15px; font-size: 13px; font-weight: 850; }
.roadmap-csharp .route-number { color: var(--csharp); background: var(--csharp-soft); }
.roadmap-vue .route-number { color: var(--vue); background: var(--vue-soft); }
.roadmap-title-row p { margin: 0; color: var(--muted); font-size: 11px; }
.roadmap-title-row h3 { margin: 2px 0 0; font-size: 24px; }
.roadmap-card ol { margin: 32px 0; padding: 0; list-style: none; counter-reset: route; }
.roadmap-card li { position: relative; display: grid; grid-template-columns: 145px 1fr; gap: 20px; padding: 14px 0 14px 30px; border-bottom: 1px solid var(--line); counter-increment: route; }
.roadmap-card li::before { content: counter(route); position: absolute; left: 0; top: 16px; color: #a0a6b7; font-size: 10px; font-weight: 800; }
.roadmap-card li span { font-weight: 750; }
.roadmap-card li small { align-self: center; color: var(--muted); font-size: 12px; }
.route-filter { padding: 10px 0; border: 0; color: var(--primary-dark); background: transparent; font-size: 13px; font-weight: 800; cursor: pointer; }
.route-filter span { margin-left: 5px; }

.about-section { overflow: clip; }
.about-inner { display: grid; grid-template-columns: 1fr 0.9fr; align-items: center; gap: 70px; }
.about-copy > p:last-child { max-width: 580px; margin: 20px 0 0; color: var(--muted); font-size: 16px; }
blockquote { position: relative; margin: 0; padding: 36px; border-radius: var(--radius-lg); background: linear-gradient(145deg, #202642, #313861); color: #fff; box-shadow: 0 20px 50px rgba(31, 37, 68, 0.2); }
blockquote > span { position: absolute; top: 10px; right: 28px; color: rgba(255,255,255,0.1); font-family: Georgia, serif; font-size: 110px; line-height: 1; }
blockquote p { position: relative; margin: 0 0 22px; font-size: 21px; font-weight: 650; line-height: 1.65; }
blockquote cite { color: #bfc5e1; font-size: 11px; font-style: normal; letter-spacing: 0.05em; }

.site-footer { padding: 45px 0; border-top: 1px solid var(--line); background: #fff; }
.footer-inner { display: flex; align-items: end; justify-content: space-between; gap: 40px; }
.footer-brand { display: inline-flex; align-items: center; text-decoration: none; }
.footer-logo { display: block; width: 150px; height: 50px; object-fit: contain; }
.footer-inner > div p { margin: 4px 0 0; color: var(--muted); font-size: 12px; }
.footer-legal { display: grid; justify-items: end; gap: 7px; }
.copyright { max-width: 680px; margin: 0; color: #8b91a3; font-size: 11px; text-align: right; }
.beian-link { color: #777e92; font-size: 12px; text-decoration: none; transition: color 0.2s ease; }
.beian-link:hover { color: var(--primary); text-decoration: underline; text-underline-offset: 3px; }

@media (max-width: 900px) {
  .hero { min-height: auto; padding: 90px 0 80px; }
  .article-grid { grid-template-columns: repeat(2, 1fr); }
  .article-card.featured { grid-column: span 2; }
  .roadmap-card li { grid-template-columns: 120px 1fr; }
  .about-inner { gap: 35px; }
}

@media (max-width: 700px) {
  .container { width: min(calc(100% - 28px), var(--container)); }
  .section { padding: 72px 0; }
  .menu-toggle { display: block; }
  .brand-logo { width: 158px; height: 53px; }
  .menu-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
  .menu-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
  .menu-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }
  .site-nav {
    position: absolute; top: 68px; left: 14px; right: 14px; display: grid; padding: 9px;
    border: 1px solid var(--line); border-radius: 15px; background: #fff; box-shadow: var(--shadow);
    opacity: 0; visibility: hidden; transform: translateY(-8px); transition: 0.2s ease;
  }
  .site-nav.is-open { opacity: 1; visibility: visible; transform: translateY(0); }
  .site-nav a { padding: 12px; }
  .hero { padding: 74px 0 62px; }
  .hero h1 { margin-top: 22px; font-size: clamp(38px, 12vw, 54px); }
  .hero-lead { font-size: 16px; }
  .search-panel { display: grid; padding: 7px; }
  .search-box { padding: 0 10px; }
  .search-button { height: 47px; }
  .hero-meta { flex-wrap: wrap; row-gap: 8px; }
  .hero-meta span { padding: 0 12px; }
  .section-heading { display: grid; align-items: start; }
  .filter-group { justify-self: stretch; }
  .filter-button { flex: 1; padding-inline: 10px; }
  .article-grid { grid-template-columns: 1fr; }
  .article-card, .article-card.featured { grid-column: auto; min-height: 380px; }
  .roadmap-grid { grid-template-columns: 1fr; }
  .roadmap-card { padding: 28px 22px; }
  .roadmap-card li { grid-template-columns: 1fr; gap: 2px; }
  .about-inner { grid-template-columns: 1fr; }
  blockquote { padding: 30px 26px; }
  .footer-inner { display: grid; }
  .footer-legal { justify-items: start; }
  .copyright { text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; }
}