:root {
  --primary: #4549e8;
  --primary-dark: #3336b7;
  --primary-soft: #eeedff;
  --orange: #f28b50;
  --ink: #202334;
  --text: #454859;
  --muted: #686a7a;
  --border: #e5e5ed;
  --background: #f8f7f3;
  --surface: #fff;
  --container: 1240px;
  --radius: 18px;
  --shadow: 0 12px 32px rgb(32 35 52 / 5%);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 110px; }
body { margin: 0; background: var(--background); color: var(--text); font: 14px/1.7 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif; }
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }
button, input, textarea, select { font: inherit; }
button { cursor: pointer; }
button:disabled { cursor: not-allowed; opacity: .5; }
button, a, input, textarea, select { outline-offset: 4px; }
:focus-visible { outline: 3px solid #8b8fff; }
button, a { -webkit-tap-highlight-color: transparent; }
input, textarea { color: var(--ink); }
.sr-only { position: absolute; width: 1px; height: 1px; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); }
.skip-link { position: fixed; left: 20px; top: -60px; z-index: 100; background: white; padding: 12px; border-radius: 8px; }
.skip-link:focus { top: 12px; }
.header { background: rgb(248 247 243 / 96%); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 40; backdrop-filter: blur(12px); }
.header-inner { max-width: 1320px; min-height: 88px; margin: auto; padding: 0 32px; display: flex; align-items: center; gap: 28px; }
.brand { flex-shrink: 0; display: flex; align-items: center; gap: 10px; color: var(--ink); }
.brand:hover { color: var(--ink); }
.brand-mark { width: 38px; height: 38px; display: grid; place-items: center; border-radius: 12px; background: var(--primary); transform: rotate(-6deg); }
.brand-mark svg { width: 27px; height: 27px; fill: none; stroke: #fff; stroke-width: 2.5; stroke-linecap: round; stroke-linejoin: round; }
.brand-name { display: flex; align-items: baseline; gap: 5px; font-size: 24px; font-weight: 800; letter-spacing: -.8px; }
.brand-cn { font-size: 15px; font-weight: 600; letter-spacing: -.3px; }
.brand-dot { color: var(--primary); margin-left: -4px; }
.top-nav { margin-left: auto; min-width: 0; }
.nav-inner { display: flex; align-items: center; gap: 4px; }
.nav-inner > a, .nav-inner > details > summary { display: block; color: #656878; font-size: 13px; font-weight: 500; white-space: nowrap; padding: 9px 10px; border-radius: 8px; }
.nav-inner > a:hover, .nav-inner > details > summary:hover { color: var(--primary); background: #efedf8; }
.nav-inner > a.active { color: var(--primary); font-weight: 700; }
.nav-inner > details { position: relative; }
.nav-inner summary { cursor: pointer; list-style: none; }
.nav-inner summary::-webkit-details-marker { display: none; }
.nav-inner summary::after { content: '⌄'; font-size: 12px; margin-left: 4px; }
.dropdown { position: absolute; top: calc(100% + 10px); left: 0; width: 185px; background: #fff; border: 1px solid var(--border); border-radius: 14px; box-shadow: var(--shadow); padding: 8px; z-index: 50; }
.dropdown a { display: block; padding: 8px 12px; border-radius: 8px; color: var(--text); font-size: 13px; }
.dropdown a:hover { color: var(--primary); background: var(--primary-soft); }
.search-form { display: flex; align-items: center; border: 1px solid #e2e1e9; width: 214px; flex-shrink: 0; background: #fff; height: 40px; border-radius: 12px; }
.search-form:focus-within { border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-soft); }
.search-form input { min-width: 0; flex: 1; border: 0; outline: 0; padding: 9px 0 9px 13px; background: transparent; font-size: 12px; }
.search-form button { width: 38px; padding: 6px; border: 0; background: transparent; color: #808294; }
.search-form svg { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-width: 1.7; vertical-align: middle; }
.home-main { max-width: var(--container); width: calc(100% - 64px); margin: auto; outline: none; }
.learning-hero { display: grid; grid-template-columns: 1.15fr 1fr; align-items: center; gap: 54px; padding: 74px 0 66px; }
.eyebrow { display: block; color: var(--primary); font-size: 10px; font-weight: 750; letter-spacing: 2px; line-height: 1.6; }
.hero-copy > .eyebrow { display: flex; align-items: center; gap: 9px; }
.eyebrow-dot { height: 6px; width: 6px; border-radius: 50%; background: var(--orange); }
.hero-copy h1 { color: var(--ink); font-size: clamp(40px, 4.2vw, 60px); font-weight: 800; letter-spacing: -2.5px; line-height: 1.25; margin: 22px 0 20px; }
.hero-copy h1 > span { display: block; color: var(--primary); }
.hero-period { color: var(--orange); }
.hero-copy > p { margin: 0; color: var(--muted); font-size: 15px; line-height: 1.9; }
.hero-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 22px; margin: 29px 0 25px; }
.primary-button, .green-button { display: inline-flex; justify-content: center; align-items: center; gap: 15px; background: var(--primary); color: #fff; border: 1px solid var(--primary); border-radius: 11px; padding: 11px 18px; line-height: 1.6; font-weight: 600; font-size: 13px; transition: background .2s, transform .2s; }
.primary-button:hover, .green-button:hover { background: var(--primary-dark); color: #fff; transform: translateY(-2px); }
.hero-secondary { color: var(--text); font-size: 12px; font-weight: 600; }
.hero-secondary span { margin-left: 6px; }
.hero-facts { display: flex; align-items: center; flex-wrap: wrap; gap: 22px; color: var(--muted); font-size: 11px; }
.hero-facts strong { color: var(--ink); font-size: 15px; margin-right: 3px; }
.hero-promise { border-left: 1px solid #d9d8e3; padding-left: 20px; }
.hero-visual { position: relative; padding: 32px 19px 26px 20px; min-width: 0; }
.hero-orbit { position: absolute; border: 1px solid #dddce8; border-radius: 50%; width: 90%; height: 90%; left: 3%; top: 0; pointer-events: none; }
.orbit-one { transform: rotate(-14deg); }
.orbit-two { transform: rotate(13deg); width: 97%; height: 80%; left: 0; top: 7%; }
.hero-sticker { position: absolute; font: 110px/1 sans-serif; color: var(--orange); right: 0; top: -24px; z-index: 2; transform: rotate(-15deg); }
.practice-window { position: relative; z-index: 1; border-radius: 18px; background: #232637; box-shadow: 0 22px 52px rgb(41 40 75 / 16%); color: #e0e2f0; transform: rotate(-3deg); overflow: hidden; }
.window-top { display: flex; align-items: center; justify-content: space-between; padding: 16px 19px; color: #85899f; font-size: 10px; border-bottom: 1px solid #36394b; letter-spacing: .2px; }
.window-dots { display: flex; gap: 5px; }
.window-dots i { width: 6px; height: 6px; border-radius: 50%; background: #767b90; }
.window-dots i:first-child { background: #f39178; }
.window-dots i:nth-child(2) { background: #edc785; }
.window-dots i:last-child { background: #9abd9a; }
.window-body { padding: 29px 20px 26px; font: 12px/2.1 "SFMono-Regular", Consolas, monospace; }
.code-line { display: flex; gap: 18px; }
.line-number { color: #656b80; flex: 0 0 18px; text-align: right; font-size: 10px; }
.syntax-comment { color: #80889f; }
.code-line b { font-weight: 400; color: #b7a2ff; }
.code-line em { color: #f6b985; font-style: normal; }
.code-line i { color: #bae0b9; font-style: normal; }
.code-indent { padding-left: 15px; }
.window-output { margin: 0 20px 17px; border: 1px solid #404456; background: #2d3042; border-radius: 11px; padding: 13px 17px; }
.output-label { display: block; font-size: 8px; letter-spacing: 1.8px; color: #8f95ac; margin-bottom: 4px; }
.window-output strong { font-size: 22px; font-weight: 700; color: #f7f6ff; }
.window-output strong span { color: #f9bf87; }
.practice-link { display: flex; align-items: center; gap: 10px; font-size: 10px; padding: 12px 20px 17px; color: #c0c2df; }
.practice-link:hover { color: white; }
.practice-link > span:last-child { margin-left: auto; }
.play-mark { color: #aeafff; font-size: 8px; }
.growth-stamp { position: absolute; bottom: 0; right: 0; z-index: 3; display: flex; align-items: center; gap: 11px; border: 1px solid #e6e4ef; border-radius: 13px; padding: 12px 17px; background: #fff; box-shadow: 0 8px 22px rgb(40 40 70 / 7%); transform: rotate(3deg); }
.stamp-check { width: 28px; height: 28px; background: #eaf3e9; color: #527553; border-radius: 50%; display: grid; place-items: center; font-size: 14px; }
.growth-stamp strong { display: block; color: var(--ink); font-size: 11px; }
.growth-stamp div > span { color: #9b9ba8; font-size: 8px; letter-spacing: 1px; }
.starter-section { padding: 20px 0 60px; border-top: 1px solid var(--border); }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 20px; margin: 27px 0 22px; }
.section-heading h2 { font-size: 25px; font-weight: 700; letter-spacing: -.5px; margin: 6px 0 0; color: var(--ink); }
.section-heading > a { flex-shrink: 0; color: var(--muted); font-size: 12px; padding-bottom: 5px; }
.starter-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 14px; }
.path-card { padding: 23px 22px 18px; border: 1px solid #deddef; background: #ecebff; border-radius: var(--radius); color: var(--ink); transition: transform .2s, box-shadow .2s; }
.path-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); color: var(--ink); }
.path-card[data-path="python3"] { background: #f3eadf; border-color: #e6dacc; }
.path-card[data-path="js"] { background: #e8eee6; border-color: #d7e2d2; }
.path-card[data-path="git"] { background: #f5e6e0; border-color: #e7d6cf; }
.path-top { display: flex; align-items: center; gap: 8px; font-size: 10px; }
.path-number { font-size: 11px; color: #898597; }
.path-label { margin-left: auto; border: 1px solid rgb(34 34 65 / 13%); border-radius: 20px; padding: 2px 10px; }
.path-top > span:last-child { font-size: 16px; margin-left: 2px; }
.path-card h3 { font-size: 18px; line-height: 1.5; margin: 23px 0 7px; }
.path-card p { font-size: 11px; color: var(--muted); margin: 0; }
.path-bottom { border-top: 1px solid rgb(34 34 65 / 10%); display: flex; justify-content: space-between; align-items: center; padding-top: 13px; margin-top: 22px; font-size: 10px; color: #6f6b7c; }
.catalog-area { padding: 38px 0 0; border-top: 1px solid var(--border); scroll-margin-top: 110px; }
.catalog-heading { position: relative; padding-right: 150px; margin-bottom: 26px; }
.catalog-heading h1, .catalog-heading h2 { color: var(--ink); font-weight: 750; font-size: 31px; line-height: 1.4; margin: 8px 0; letter-spacing: -.5px; }
.catalog-heading > p { font-size: 13px; color: var(--muted); margin: 0; }
.catalog-count { position: absolute; right: 0; bottom: 8px; padding: 5px 11px; border: 1px solid var(--border); border-radius: 20px; font-size: 10px; color: var(--muted); }
.catalog-filters { margin-bottom: 36px; }
.catalog-filters .sidebar { border: 0; background: transparent; padding: 0; position: static; box-shadow: none; }
.catalog-filters .sidebar-title { display: none; }
.catalog-filters .category-links { display: flex; flex-wrap: wrap; gap: 8px; }
.catalog-filters .category-link { padding: 7px 12px; border: 1px solid #e4e2eb; border-radius: 9px; background: transparent; margin: 0; color: var(--muted); font-size: 11px; }
.catalog-filters .category-link.active { background: var(--ink); border-color: var(--ink); color: #fff; }
.catalog-filters .category-link.active .category-symbol { color: #fff; }
.catalog-section { margin: 0 0 38px; }
.catalog-section-heading { display: flex; align-items: center; justify-content: space-between; margin-bottom: 17px; }
.catalog-section-heading > span { color: var(--muted); font-size: 10px; }
.section-title { display: flex; align-items: center; gap: 10px; font-size: 19px; color: var(--ink); font-weight: 700; margin: 0 0 15px; }
.catalog-section-heading .section-title { margin: 0; }
.section-index { color: var(--muted); font: 10px/1.5 Consolas, monospace; padding: 4px 6px; border: 1px solid #e4e2e9; border-radius: 5px; }
.course-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 15px; }
.course-card { display: flex; flex-direction: column; gap: 18px; min-width: 0; min-height: 200px; padding: 21px 22px 16px; border: 1px solid #e4e3eb; border-radius: 16px; background: #fff; color: var(--ink); transition: border-color .2s, transform .2s, box-shadow .2s; }
.course-card:hover { transform: translateY(-3px); border-color: #bcbdf7; color: var(--ink); box-shadow: var(--shadow); }
.course-card-top { display: flex; justify-content: space-between; align-items: center; gap: 8px; }
.course-icon { width: 38px; height: 38px; flex: 0 0 38px; background: #eeedff; color: #5b53b1; display: flex; align-items: center; justify-content: center; border-radius: 11px; font: 700 15px/1 -apple-system, BlinkMacSystemFont, sans-serif; letter-spacing: -.4px; }
.course-icon[data-theme="python"], .course-icon[data-theme="database"] { background: #eaf1f5; color: #406580; }
.course-icon[data-theme="ai"], .course-icon[data-theme="basics"] { background: #f1eafb; color: #7c5899; }
.course-icon[data-theme="backend"], .course-icon[data-theme="devops"] { background: #f9ece4; color: #a16444; }
.course-icon[data-theme="mobile"], .course-icon[data-theme="language"] { background: #eaf1e8; color: #577356; }
.course-icon[data-theme="xml"], .course-icon[data-theme="web"] { background: #f5eaec; color: #965d70; }
.course-icon.has-logo { background: #fff; border: 1px solid #ecebf2; }
.course-logo { display: block; width: 28px; height: 28px; object-fit: contain; }
.has-logo .logo-fallback { display: none; }
.course-level { font-size: 9px; color: var(--muted); }
.course-copy { min-width: 0; }
.course-copy h3 { font-size: 16px; line-height: 1.4; margin: 0 0 8px; font-weight: 700; color: var(--ink); overflow-wrap: anywhere; }
.course-copy p { margin: 0; font-size: 12px; color: var(--muted); line-height: 1.75; }
.course-card-bottom { margin-top: auto; display: flex; align-items: center; justify-content: space-between; padding-top: 13px; border-top: 1px solid #f0eef4; font-size: 10px; color: var(--muted); }
.card-arrow { width: 21px; height: 21px; display: grid; place-items: center; color: #898ca9; font-size: 15px; }
.learning-banner { display: flex; align-items: center; justify-content: space-between; gap: 30px; padding: 37px 42px; border-radius: 22px; background: #eeedfc; margin: 44px 0 64px; border: 1px solid #e1def8; }
.learning-banner h2 { margin: 7px 0 8px; color: var(--ink); font-size: 28px; }
.learning-banner p { margin: 0; color: var(--muted); font-size: 12px; }
.learning-banner > a { flex-shrink: 0; }
.layout { max-width: var(--container); width: calc(100% - 64px); margin: 34px auto 60px; display: grid; grid-template-columns: 205px minmax(0, 1fr); gap: 28px; align-items: start; }
.sidebar { background: #fff; border: 1px solid var(--border); border-radius: 16px; padding: 16px 10px; min-width: 0; position: sticky; top: 116px; }
.sidebar-title { display: flex; align-items: center; gap: 8px; margin: 0 0 13px; padding: 3px 10px 14px; border-bottom: 1px solid #efedf5; color: var(--ink); font-size: 13px; font-weight: 700; }
.category-link { display: flex; align-items: center; gap: 9px; color: var(--muted); padding: 9px 10px; border-radius: 8px; font-size: 11px; margin: 2px 0; }
.category-link:hover, .category-link.active { background: var(--primary-soft); color: var(--primary); }
.category-symbol { width: 15px; text-align: center; color: #9697ac; font-size: 13px; }
.main-panel { background: #fff; border: 1px solid var(--border); border-radius: 20px; padding: 30px; min-width: 0; outline: none; }
.layout .course-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.mobile-category-toggle { display: none; }
.search-heading { display: flex; align-items: center; justify-content: space-between; gap: 20px; margin-bottom: 28px; }
.search-heading h1 { color: var(--ink); font-size: 27px; margin: 0; font-weight: 700; }
.muted { color: var(--muted); font-size: 12px; }
.empty { padding: 70px 20px; text-align: center; color: #858694; }
.empty h1, .empty h2 { color: var(--ink); font-size: 23px; font-weight: 650; margin: 0 0 10px; }
.empty p { margin: 0 0 24px; }
#footer { border-top: 1px solid var(--border); background: #f2f1ed; }
.footer-inner { max-width: var(--container); width: calc(100% - 64px); margin: auto; padding: 54px 0 40px; display: grid; grid-template-columns: 1.6fr repeat(3, 1fr); gap: 42px; }
.footer-wordmark { display: inline-block; color: var(--ink); font-size: 34px; font-weight: 800; letter-spacing: -1.5px; }
.footer-wordmark span { color: var(--primary); }
.footer-brand p { font-size: 12px; color: var(--muted); margin: 8px 0 14px; }
.footer-note { font-size: 10px; color: var(--muted); }
.footer-inner h3 { color: var(--ink); font-size: 12px; font-weight: 700; margin: 7px 0 17px; }
.footer-inner > div:not(.footer-brand) a { display: block; font-size: 11px; color: var(--muted); margin: 10px 0; }
.footer-inner a:hover { color: var(--primary); }
.copyright { max-width: var(--container); width: calc(100% - 64px); margin: auto; padding: 20px 0 24px; border-top: 1px solid #dedde4; display: flex; align-items: center; justify-content: space-between; color: var(--muted); font-size: 10px; }
.footer-spark { display: inline-block; color: var(--orange); font-size: 17px; margin-left: 12px; vertical-align: middle; }
.back-top { position: fixed; right: 22px; bottom: 22px; height: 40px; width: 40px; background: white; color: var(--primary); border: 1px solid #dfdef0; border-radius: 13px; font-size: 20px; box-shadow: var(--shadow); z-index: 12; }
.toast { position: fixed; bottom: 30px; left: 50%; transform: translateX(-50%); max-width: calc(100% - 30px); width: max-content; border-radius: 12px; background: var(--ink); color: #fff; padding: 12px 22px; z-index: 100; opacity: 0; pointer-events: none; transition: opacity .2s; box-shadow: var(--shadow); }
.toast.visible { opacity: 1; }
.article-layout { grid-template-columns: 205px minmax(0, 1fr) 145px; gap: 24px; }
.chapter-link { display: block; padding: 9px 10px; color: var(--muted); font-size: 11px; line-height: 1.5; border-radius: 8px; margin: 2px 0; }
.chapter-link:hover { background: #f5f4fb; color: var(--primary); }
.chapter-link.active { background: var(--primary-soft); color: var(--primary); font-weight: 650; }
.chapter-group { font-size: 10px; color: var(--muted); font-weight: 600; letter-spacing: 1px; padding: 18px 10px 8px; margin-top: 6px; border-top: 1px solid #efedf5; }
.article-panel { padding: 30px 34px; }
.breadcrumb { font-size: 10px; color: var(--muted); padding-bottom: 18px; margin-bottom: 23px; border-bottom: 1px solid #efedf5; }
.breadcrumb a { color: #8a879d; }
.article-panel h1 { color: var(--ink); font-size: 34px; font-weight: 750; line-height: 1.4; margin: 12px 0 18px; letter-spacing: -.5px; }
.article-panel h1 span { color: var(--primary); }
.article-panel h2 { color: var(--ink); font-size: 23px; margin: 34px 0 14px; font-weight: 700; }
.article-panel h3 { font-size: 18px; font-weight: 600; margin: 20px 0 10px; color: var(--ink); }
.article-panel p { line-height: 2; margin: 15px 0; }
.article-panel ul, .article-panel ol { padding-left: 24px; line-height: 2.1; }
.article-panel hr { border: 0; border-top: 1px solid var(--border); margin: 25px 0; }
.article-meta { display: flex; align-items: center; gap: 12px; font-size: 10px; color: var(--muted); margin-bottom: 18px; flex-wrap: wrap; }
.article-meta > span:first-child { background: #f3f2fb; color: #8983ae; padding: 3px 8px; border-radius: 5px; }
.save-button { margin-left: auto; border: 1px solid #e3e0ee; border-radius: 9px; background: #fff; color: var(--muted); font-size: 10px; padding: 6px 10px; }
.save-button.saved { color: var(--primary); background: var(--primary-soft); border-color: #d0cdf4; }
.page-navigation { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin: 22px 0 30px; }
.page-navigation a { padding: 8px 12px; background: #faf9fd; border: 1px solid #e9e6f2; border-radius: 9px; color: var(--muted); font-size: 11px; }
.page-navigation a:hover { color: var(--primary); background: var(--primary-soft); }
.page-navigation .next { margin-left: auto; }
.notice { border: 1px solid #e3e0f6; border-radius: 11px; background: #f6f4ff; color: var(--muted); padding: 15px 18px; font-size: 12px; line-height: 1.9; margin: 24px 0; }
.example-box { background: #f6f5fa; border: 1px solid #e7e4f0; border-radius: 14px; padding: 18px; margin: 22px 0; }
.example-heading { display: flex; justify-content: space-between; align-items: center; margin-bottom: 13px; }
.example-heading h3 { margin: 0; font-size: 14px; font-weight: 700; }
.copy-button { border: 1px solid #dedbe9; border-radius: 7px; background: transparent; font-size: 10px; padding: 5px 9px; color: #8d869f; }
.code { background: #25283b; border: 0; border-radius: 10px; color: #d9dced; padding: 20px; font: 12px/1.9 "SFMono-Regular", Consolas, monospace; white-space: pre-wrap; overflow-wrap: anywhere; margin: 0 0 16px; }
.secondary { display: inline-block; padding: 10px 16px; background: #fff; border: 1px solid #dedbe9; border-radius: 10px; color: #817b94; font-size: 12px; }
.secondary:hover { background: #f3f1fb; color: var(--primary); }
.reference-table { border-collapse: collapse; width: 100%; margin: 22px 0; font-size: 12px; table-layout: fixed; }
.reference-table th, .reference-table td { border-bottom: 1px solid #e7e4ef; text-align: left; padding: 15px 12px; overflow-wrap: anywhere; }
.reference-table th { background: #f5f3fb; font-size: 11px; color: #8b83a0; }
.reference-table tr:nth-child(even) { background: #faf9fd; }
.reference-table code, .article-panel p code { background: #efecfa; border-radius: 5px; padding: 2px 5px; color: #71609b; font-size: 11px; }
.article-toc { position: sticky; top: 120px; padding: 10px 0 0 15px; border-left: 1px solid #e2deeb; }
.article-toc h3 { margin: 0 0 17px; color: var(--ink); font-size: 11px; font-weight: 700; }
.article-toc a { display: block; color: var(--muted); font-size: 10px; padding: 7px 0; }
.article-toc a:hover { color: var(--primary); }
.article-toc hr { border: 0; border-top: 1px solid #e5e0ef; margin: 15px 0; }
.reading-progress { height: 3px; background: #e9e5f1; margin-top: 15px; border-radius: 3px; }
.reading-progress > span { display: block; width: 0; height: 100%; background: var(--primary); border-radius: 3px; }
.notes-area { border-top: 1px solid #e7e3f0; padding-top: 30px; margin-top: 34px; }
.notes-area h2 { font-size: 20px; margin: 0; }
.notes-header { display: flex; align-items: center; justify-content: space-between; gap: 15px; }
.note-card { background: #faf9fd; border: 1px solid #e8e3f2; border-radius: 14px; padding: 22px; margin: 20px 0; }
.note-card h3 { font-size: 16px; margin: 0; }
.note-card p { white-space: pre-wrap; overflow-wrap: anywhere; font-size: 13px; margin: 12px 0; }
.note-card time { font-size: 10px; color: var(--muted); }
.note-actions { display: flex; gap: 15px; margin-top: 15px; }
.text-button { color: #8f80ad; border: 0; background: transparent; padding: 0; font-size: 11px; }
.page-title { color: var(--ink); font-size: 29px; font-weight: 750; line-height: 1.4; margin: 0 0 12px; }
.toolbar { display: flex; justify-content: space-between; align-items: center; gap: 18px; flex-wrap: wrap; border-bottom: 1px solid #ede8f5; padding-bottom: 23px; margin-bottom: 25px; }
.bookmark-row { display: flex; align-items: center; gap: 15px; padding: 18px 2px; border-bottom: 1px solid #eeebf5; min-width: 0; }
.bookmark-copy { flex: 1; min-width: 0; }
.bookmark-row h3 { font-size: 15px; margin: 0 0 3px; overflow-wrap: anywhere; }
.bookmark-row time { color: var(--muted); font-size: 10px; }
.remove-bookmark { background: transparent; border: 0; padding: 8px; color: #9c91ad; font-size: 20px; }
.stat-tag { padding: 4px 11px; background: var(--primary-soft); color: var(--primary); border-radius: 20px; font-size: 11px; }
.tool-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; margin: 28px 0; }
.tool-card { border: 1px solid #e5dff0; border-radius: 16px; background: #fbf9fd; padding: 25px; transition: border-color .2s; }
.tool-card:hover { border-color: #c4b8e8; }
.tool-card h2 { color: var(--primary); font-size: 17px; margin: 0 0 12px; }
.tool-card p { color: var(--muted); font-size: 11px; margin: 0; }
.tool-input { display: block; width: 100%; padding: 17px; border: 1px solid #e0d9ec; border-radius: 12px; font: 13px/1.8 "SFMono-Regular", Consolas, monospace; resize: vertical; min-height: 210px; background: #fcfbfd; margin-top: 10px; }
.tool-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin: 20px 0; }
.tool-output { white-space: pre-wrap; overflow-wrap: anywhere; border: 1px solid #e3dcec; border-radius: 12px; padding: 20px; background: #f7f4fc; min-height: 90px; font: 12px/1.9 "SFMono-Regular", Consolas, monospace; }
.tool-error { color: #b55155; font-size: 12px; }
.quiz-choice { display: block; padding: 15px 18px; border: 1px solid #e4ddee; border-radius: 12px; cursor: pointer; background: #fbf9fd; margin: 13px 0; }
.quiz-choice:has(input:checked) { border-color: var(--primary); background: var(--primary-soft); }
.quiz-choice input { accent-color: var(--primary); margin-right: 13px; }
.quiz-progress { height: 5px; background: #eee9f5; border-radius: 4px; margin: 24px 0; }
.quiz-progress span { display: block; height: 100%; border-radius: 4px; background: var(--primary); }
.quiz-result { padding: 40px 10px; text-align: center; }
.quiz-result strong { display: block; font-size: 64px; font-weight: 750; color: var(--primary); }
.question-feedback { border: 1px solid #dbe9d9; border-radius: 12px; padding: 18px; color: #62795f; background: #f0f7ef; margin: 20px 0; }
.question-feedback.wrong { border-color: #f1d8c8; color: #a8785c; background: #fff5ef; }
.quiz-review { padding: 23px 0; border-bottom: 1px solid #e6deef; }
.quiz-review h3 { color: var(--ink); font-size: 15px; margin: 0; }
.quiz-review p { font-size: 12px; color: var(--muted); }
.reference-tabs { display: flex; flex-wrap: wrap; gap: 8px; margin: 25px 0; }
.reference-tabs button { border: 1px solid #e1d7eb; background: #fff; color: #8a789d; border-radius: 8px; padding: 8px 14px; font-size: 12px; }
.reference-tabs button.active { background: var(--primary); color: #fff; border-color: var(--primary); }
.filter-input { max-width: 100%; width: 250px; padding: 10px 13px; border: 1px solid #e1d9eb; border-radius: 9px; background: #fcfbfd; margin: 5px 0 10px; }
#color-preview { border-radius: 14px; }
dialog { border: 1px solid #ded5eb; padding: 30px; color: var(--text); border-radius: 20px; width: 580px; max-width: calc(100% - 30px); box-shadow: 0 24px 90px #24233b33; }
dialog::backdrop { background: #23213970; backdrop-filter: blur(4px); }
.dialog-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 25px; }
.dialog-head h2 { color: var(--ink); margin: 0; font-size: 24px; font-weight: 700; }
.dialog-head button { border: 0; background: transparent; color: #aa9eba; font-size: 28px; }
dialog label { display: block; margin: 15px 0 7px; font-size: 12px; color: var(--muted); }
dialog input, dialog textarea { width: 100%; padding: 12px; border: 1px solid #e1d8ec; border-radius: 10px; resize: vertical; background: #fcfbfd; }
.dialog-actions { display: flex; gap: 10px; justify-content: flex-end; margin-top: 22px; }
.editor-layout { max-width: 1340px; width: calc(100% - 64px); margin: 35px auto 60px; }
.editor-bar { display: flex; align-items: center; flex-wrap: wrap; gap: 10px; margin-bottom: 25px; }
.editor-bar h1 { margin: 0 auto 0 0; font-size: 27px; font-weight: 750; color: var(--ink); }
.editor-columns { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 22px; }
.editor-pane { min-width: 0; border: 1px solid #e0d9ec; border-radius: 17px; overflow: hidden; background: #fff; }
.pane-header { display: flex; align-items: center; justify-content: space-between; padding: 14px 20px; border-bottom: 1px solid #e7e0ef; background: #f3f0f9; color: #8b779e; font-size: 11px; }
.code-editor { width: 100%; height: 540px; border: 0; padding: 22px; display: block; resize: vertical; font: 13px/1.9 "SFMono-Regular", Consolas, monospace; tab-size: 2; color: #d7d6eb; background: #25283b; }
.code-editor:focus-visible { outline: 3px solid #9e96f0; outline-offset: -4px; }
.preview-frame { width: 100%; height: 540px; border: 0; display: block; background: #fff; }
.editor-help { color: var(--muted); font-size: 11px; margin-top: 18px; }
.editor-output { padding: 22px; white-space: pre-wrap; overflow-wrap: anywhere; font: 13px/1.8 "SFMono-Regular", Consolas, monospace; }
.web-status-row, .web-console-header { display:flex; align-items:center; justify-content:space-between; gap:12px; padding:10px 20px; font-size:10px; color:var(--muted); background:#faf9fd; border-bottom:1px solid var(--border); }
.web-status-row span:last-child { font-size:9px; }
#web-status[data-error="true"], .console-error { color:#b43f55; }
.console-warn { color:#986129; }
.web-status-row + .preview-frame { display:block; height:350px; }
.web-console-header { border-top:1px solid var(--border); }
.web-console { height:130px; overflow:auto; white-space:pre-wrap; overflow-wrap:anywhere; padding:14px 20px; margin:0; background:#fff; font:12px/1.8 "SFMono-Regular",Consolas,monospace; }
.web-console[data-placeholder="true"] { color:#a39caf; }
.web-console > span { display:block; }
.chapter-count { margin:0 15px 15px; font-size:11px; color:var(--muted); }
.rich-article .lesson-title { display:block; color:var(--ink); margin-top:6px; font-size:.78em; }
.lesson-intro { color:#4f5065; font-size:15px; }
.lesson-section { scroll-margin-top:110px; margin:34px 0; }
.lesson-section h2 { margin-top:0; }
.lesson-section li { margin:9px 0; line-height:1.9; }
.lesson-table-wrap { overflow-x:auto; border:1px solid #e4e1ef; border-radius:12px; margin:22px 0; }
.lesson-table { border-collapse:collapse; width:100%; min-width:420px; font-size:12px; line-height:1.9; }
.lesson-table th { background:#f4f2fc; text-align:left; color:#454269; padding:13px 17px; font-weight:650; }
.lesson-table td { padding:14px 17px; border-top:1px solid #e9e6f1; vertical-align:top; }
.lesson-table tr:nth-child(even) td { background:#fcfbfe; }
.lesson-figure { margin:22px 0; }
.lesson-figure img { width:100%; height:auto; display:block; border-radius:14px; }
.lesson-figure figcaption { color:var(--muted); font-size:11px; line-height:1.8; margin-top:10px; }
.version-note { margin:24px 0; padding:17px 20px; background:#fff6ea; border:1px solid #f2ddbc; border-radius:12px; font-size:12px; }
.version-note p { margin:7px 0 0; }
.expected-output { background:#f6f8fa; border:1px solid #e4e5eb; border-radius:9px; padding:15px 17px; margin:18px 0; }
.expected-output strong { font-size:11px; color:#667069; }
.expected-output pre { white-space:pre-wrap; overflow-wrap:anywhere; margin:8px 0 0; font:12px/1.9 "SFMono-Regular",Consolas,monospace; }
.exercise-task { border-left:3px solid var(--primary); padding:1px 18px; background:#f8f7fd; }
.exercise-solution { border:1px solid #e4e0ef; border-radius:10px; margin-top:18px; }
.exercise-solution summary { padding:13px 17px; font-size:12px; color:var(--primary); font-weight:600; cursor:pointer; }
.exercise-solution > div { padding:0 18px 12px; border-top:1px solid #e9e6f0; }
.exercise-solution p { white-space:pre-wrap; font-size:12px; }
.lesson-sources p { font-size:11px; color:var(--muted); }
.course-roadmap { display:grid; grid-template-columns:repeat(2,minmax(0,1fr)); gap:9px; }
.course-roadmap a { display:flex; align-items:center; gap:10px; padding:12px 14px; border:1px solid #e6e2f0; border-radius:9px; font-size:11px; color:var(--text); }
.course-roadmap a span:first-child { font:10px monospace; color:#9890ac; }
.course-roadmap a span:last-child { margin-left:auto; color:var(--primary); }
.course-roadmap a:hover { background:#f5f3fd; border-color:#cbc5ef; }
@media(max-width:760px){.course-roadmap{grid-template-columns:1fr}.lesson-table th,.lesson-table td{padding:11px}.rich-article .lesson-title{font-size:.85em}}
.python-editor button[hidden], .python-message[hidden] { display: none; }
.editor-bar button:disabled, .result-actions button:disabled { cursor: wait; opacity: .65; transform: none; }
.editor-bar .stop-button { color: #ab3b50; border-color: #eed5dc; }
.result-actions { display: flex; align-items: center; gap: 18px; }
.result-actions .text-button { padding: 3px 0 3px 8px; }
.python-editor .code-editor { tab-size: 4; resize: none; }
.python-input { border-top: 1px solid #e0d9ec; background: #faf9fd; }
.python-input summary { padding: 14px 20px; font-size: 12px; font-weight: 600; cursor: pointer; }
.python-input summary span { color: var(--muted); font-weight: 400; font-size: 11px; margin-left: 10px; }
.python-input textarea { display: block; width: calc(100% - 40px); margin: 0 20px 18px; padding: 12px; border: 1px solid #e0d9ec; border-radius: 8px; background: #fff; font: 13px/1.7 "SFMono-Regular", Consolas, monospace; resize: vertical; }
.python-status-row { display: flex; justify-content: space-between; align-items: center; gap: 15px; padding: 16px 22px 0; color: var(--muted); font-size: 11px; }
.python-status { display: inline-flex; align-items: center; gap: 7px; }
.python-status::before { content: ''; width: 6px; height: 6px; border-radius: 50%; background: #aaa4bc; }
.python-status[data-phase="loading"]::before, .python-status[data-phase="running"]::before { background: var(--primary); animation: python-pulse 1s ease-in-out infinite alternate; }
.python-status[data-phase="done"] { color: #287458; }
.python-status[data-phase="done"]::before { background: #287458; }
.python-status[data-phase="error"], .python-status[data-phase="timeout"], .python-status[data-phase="limit"] { color: #b43f55; }
.python-status[data-phase="error"]::before, .python-status[data-phase="timeout"]::before, .python-status[data-phase="limit"]::before { background: #b43f55; }
.python-output { height: 483px; overflow: auto; margin: 0; color: var(--ink); }
.python-output[data-placeholder="true"] { color: #aaa4bc; }
.python-stderr { color: #b43f55; }
.python-message { margin: 0; padding: 12px 22px 18px; font-size: 11px; color: var(--muted); overflow-wrap: anywhere; }
.python-message.is-error { color: #b43f55; }
@keyframes python-pulse { from { opacity: .35; } to { opacity: 1; } }
@media (prefers-reduced-motion: reduce) { .python-status::before { animation: none !important; } }
@media (max-width: 760px) { .python-output { height: 320px; } .python-input summary span { display: block; margin: 5px 0 0; } }
.info-prose { max-width: 720px; }
.info-prose h2 { font-size: 22px; color: var(--ink); margin: 35px 0 12px; }
.info-prose p { font-size: 14px; line-height: 2; color: var(--muted); }
.about-lead { font-size: 17px !important; color: #72627f !important; }
@media (max-width: 1220px) {
  .header-inner { flex-wrap: wrap; gap: 12px 25px; padding-top: 16px; padding-bottom: 12px; }
  .top-nav { order: 3; width: 100%; margin-left: 0; }
  .nav-inner { gap: 14px; }
  .search-form { margin-left: auto; width: 260px; }
  .header { position: relative; }
  .article-layout { grid-template-columns: 190px minmax(0, 1fr); gap: 22px; }
  .article-toc { display: none; }
  .sidebar { top: 25px; }
  .learning-hero { gap: 28px; padding-top: 55px; }
  .hero-copy h1 { font-size: 48px; }
  .hero-actions { gap: 17px; }
  .hero-secondary { font-size: 11px; }
  .hero-facts { gap: 14px; }
  .hero-promise { padding-left: 12px; }
  .hero-visual { padding-left: 10px; padding-right: 10px; }
  .window-body { font-size: 11px; }
  .course-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .layout .course-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .path-card { padding: 20px 17px 16px; }
  .path-card h3 { font-size: 16px; }
}
@media (max-width: 960px) {
  .learning-hero { grid-template-columns: 1.1fr 1fr; gap: 18px; padding-top: 45px; padding-bottom: 50px; }
  .hero-copy h1 { font-size: 39px; letter-spacing: -1.5px; }
  .hero-copy > p { font-size: 12px; }
  .hero-actions { display: block; margin-top: 22px; }
  .hero-secondary { display: block; margin-top: 17px; }
  .hero-facts { gap: 13px; }
  .hero-promise { width: 100%; padding: 0; border: 0; }
  .hero-sticker { font-size: 78px; top: -2px; }
  .window-body { font-size: 9px; padding: 23px 12px; }
  .code-line { gap: 10px; }
  .growth-stamp { padding: 10px 12px; }
  .growth-stamp strong { font-size: 9px; }
  .starter-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .path-card h3 { font-size: 19px; margin-top: 20px; }
  .path-card p { font-size: 12px; }
  .layout { grid-template-columns: 170px minmax(0, 1fr); gap: 20px; }
  .main-panel { padding: 24px; }
  .article-panel { padding: 25px; }
  .article-panel h1 { font-size: 28px; }
  .tool-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-inner { gap: 25px; }
  .learning-banner { padding: 28px; }
  .learning-banner h2 { font-size: 24px; }
}
@media (max-width: 760px) {
  html { scroll-padding-top: 25px; }
  .header-inner { padding: 17px 20px 12px; gap: 14px; }
  .brand-name { font-size: 22px; }
  .brand-cn { font-size: 13px; }
  .brand-mark { width: 33px; height: 33px; border-radius: 10px; }
  .search-form { width: 190px; }
  .nav-inner { gap: 6px; flex-wrap: wrap; justify-content: space-between; }
  .nav-inner > a, .nav-inner > details > summary { padding: 7px 4px; font-size: 12px; }
  .home-main, .layout, .editor-layout, .footer-inner, .copyright { width: calc(100% - 40px); }
  .learning-hero { display: block; padding: 39px 0 45px; }
  .hero-copy h1 { font-size: 46px; letter-spacing: -1.8px; }
  .hero-copy > p { font-size: 13px; }
  .hero-actions { display: flex; gap: 19px; margin: 25px 0; }
  .hero-secondary { margin: 0; }
  .hero-facts { gap: 15px; }
  .hero-promise { width: auto; padding-left: 15px; border-left: 1px solid #ded9e8; }
  .hero-visual { max-width: 430px; margin: 43px auto 0; padding: 24px 18px 23px; }
  .window-body { font-size: 12px; padding: 25px 20px; }
  .hero-sticker { font-size: 85px; top: -20px; }
  .growth-stamp { padding: 10px 14px; }
  .growth-stamp strong { font-size: 11px; }
  .section-heading { align-items: start; }
  .section-heading h2 { font-size: 23px; max-width: 350px; }
  .section-heading > a { font-size: 10px; margin-top: 20px; }
  .starter-section { padding-bottom: 35px; }
  .catalog-heading { padding-right: 0; }
  .catalog-heading h1, .catalog-heading h2 { font-size: 25px; }
  .catalog-count { display: inline-block; position: static; margin-top: 13px; }
  .catalog-area { padding-top: 30px; scroll-margin-top: 25px; }
  .course-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 13px; }
  .course-card { padding: 18px 17px 13px; min-height: 188px; gap: 17px; }
  .course-copy h3 { font-size: 15px; }
  .catalog-filters .sidebar { display: none; }
  .catalog-filters .sidebar.mobile-open { display: block; margin-top: 15px; }
  .mobile-category-toggle { width: 100%; display: flex; align-items: center; justify-content: space-between; padding: 12px 14px; border: 1px solid #e2dbea; border-radius: 11px; background: #fff; color: #877897; font-size: 12px; }
  .layout { display: block; margin-top: 23px; }
  .layout > .mobile-category-toggle { margin-bottom: 14px; }
  .layout > .sidebar { display: none; position: static; margin-bottom: 18px; }
  .layout > .sidebar.mobile-open { display: block; }
  .category-links { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 4px; }
  .chapter-sidebar { max-height: 400px; overflow-y: auto; }
  .main-panel { border-radius: 16px; padding: 23px; }
  .layout .course-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .article-panel h1 { font-size: 29px; }
  .article-panel h2 { font-size: 21px; }
  .article-panel p { font-size: 13px; }
  .article-meta { gap: 10px; }
  .code { font-size: 11px; padding: 16px; }
  .example-box { padding: 14px; }
  .learning-banner { display: block; padding: 29px 25px; margin: 32px 0 45px; }
  .learning-banner > a { margin-top: 23px; }
  .footer-inner { grid-template-columns: repeat(3, minmax(0, 1fr)); padding-top: 35px; gap: 20px; }
  .footer-brand { grid-column: 1 / -1; margin-bottom: 10px; }
  .footer-wordmark { font-size: 30px; }
  .copyright { align-items: start; gap: 15px; padding-bottom: 45px; }
  .editor-columns { grid-template-columns: 1fr; gap: 20px; }
  .code-editor { height: 360px; font-size: 12px; }
  .preview-frame { height: 360px; }
  .editor-bar h1 { width: 100%; margin-bottom: 10px; font-size: 24px; }
  .search-heading { display: block; }
  .search-heading h1 { font-size: 25px; margin-bottom: 10px; }
  .page-title { font-size: 26px; }
  .tool-actions { align-items: start; }
  .tool-actions label { max-width: 100%; }
  .reference-table th, .reference-table td { padding: 11px 7px; font-size: 11px; }
  .toast { bottom: 70px; }
  .back-top { right: 12px; bottom: 14px; }
}
@media (max-width: 480px) {
  .header-inner { gap: 14px 12px; }
  .brand { gap: 8px; }
  .brand-name { font-size: 23px; }
  .search-form { order: 2; width: 100%; height: 38px; }
  .top-nav { order: 3; }
  .nav-inner { gap: 0; justify-content: space-between; }
  .nav-inner > a, .nav-inner > details > summary { font-size: 11px; padding: 6px 2px; }
  .dropdown { width: 155px; }
  .nav-inner > details:nth-of-type(2) .dropdown { left: auto; right: 0; }
  .hero-copy h1 { font-size: clamp(34px, 10.5vw, 42px); margin-top: 19px; }
  .hero-actions { gap: 17px; }
  .primary-button, .green-button { padding: 10px 14px; font-size: 12px; }
  .hero-secondary { font-size: 11px; }
  .hero-facts { font-size: 10px; gap: 15px; }
  .hero-promise { width: 100%; border: 0; padding: 0; }
  .hero-visual { padding: 25px 9px 23px; }
  .window-body { font-size: 10px; padding: 24px 15px; }
  .window-top { padding: 15px; font-size: 9px; }
  .hero-sticker { font-size: 75px; right: 2px; }
  .hero-orbit { width: 84%; height: 80%; left: 8%; top: 8%; }
  .growth-stamp { right: 0; }
  .section-heading { display: block; }
  .section-heading h2 { font-size: 22px; }
  .section-heading > a { display: inline-block; margin-top: 14px; }
  .path-card { padding: 17px 14px 14px; }
  .path-card h3 { font-size: 15px; line-height: 1.5; margin-top: 18px; }
  .path-card p { font-size: 10px; min-height: 34px; }
  .path-top { gap: 5px; }
  .path-label { padding: 2px 6px; font-size: 8px; }
  .path-number { font-size: 9px; }
  .path-top > span:last-child { font-size: 13px; }
  .path-bottom { font-size: 9px; }
  .catalog-heading h1, .catalog-heading h2 { font-size: 23px; }
  .catalog-heading > p { font-size: 11px; }
  .section-title { font-size: 16px; }
  .section-index { font-size: 9px; padding: 3px 4px; }
  .catalog-section-heading > span { font-size: 9px; }
  .course-grid { gap: 10px; }
  .course-card { padding: 15px 13px 12px; gap: 15px; min-height: 192px; border-radius: 13px; }
  .course-icon { width: 33px; height: 33px; flex-basis: 33px; font-size: 13px; border-radius: 10px; }
  .course-logo { width: 25px; height: 25px; }
  .course-level { font-size: 8px; }
  .course-copy h3 { font-size: 13px; margin-bottom: 8px; }
  .course-copy p { font-size: 11px; line-height: 1.7; }
  .course-card-bottom { font-size: 9px; padding-top: 11px; }
  .main-panel { padding: 20px 17px; }
  .layout .course-grid { grid-template-columns: 1fr; }
  .article-panel h1 { font-size: 26px; }
  .article-meta { gap: 7px; font-size: 9px; }
  .save-button { font-size: 9px; padding: 5px 8px; }
  .page-navigation a { font-size: 10px; padding: 7px 8px; }
  .notes-header { flex-wrap: wrap; }
  .note-card { padding: 17px; }
  .tool-grid { grid-template-columns: 1fr; }
  .learning-banner h2 { font-size: 23px; }
  .footer-inner { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-inner > div:last-child { grid-column: 1 / -1; }
  .footer-inner > div:last-child a { display: inline-block; margin-right: 15px; }
  .copyright { font-size: 9px; }
  .footer-spark { margin-left: 5px; }
  dialog { padding: 23px; }
  .dialog-head h2 { font-size: 21px; }
}
@media (max-width: 350px) {
  .starter-grid, .course-grid { grid-template-columns: 1fr; }
  .hero-copy h1 { font-size: 32px; }
  .window-body { font-size: 9px; }
  .nav-inner > a, .nav-inner > details > summary { font-size: 10px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}