:root {
  --ink: #202126;
  --muted: #656770;
  --line: #dedfe3;
  --paper: #fbfaf8;
  --surface: #ffffff;
  --primary: #c73d6d;
  --primary-dark: #9f2c53;
  --secondary: #2f6f6b;
  --soft-pink: #f8e9ee;
  --soft-green: #e8f1ef;
  --max: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "微软雅黑", Arial, Helvetica, sans-serif; line-height: 1.75; }
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; }

.site-header { position: relative; z-index: 20; border-bottom: 1px solid var(--line); background: rgba(251, 250, 248, 0.96); }
.header-inner, .section-inner, .hero-inner, .footer-inner { width: min(calc(100% - 48px), var(--max)); margin-inline: auto; }
.header-inner { min-height: 74px; display: flex; align-items: center; justify-content: space-between; gap: 28px; }
.brand { display: inline-flex; align-items: center; gap: 11px; font-weight: 800; font-size: 18px; }
.brand img, .footer-brand img { border-radius: 6px; object-fit: cover; }
.site-nav { display: flex; align-items: center; gap: 30px; font-size: 14px; font-weight: 700; }
.site-nav > a:not(.nav-download) { padding: 24px 0 20px; border-bottom: 3px solid transparent; }
.site-nav > a.is-active { color: var(--primary-dark); border-color: var(--primary); }
.nav-download { min-width: 104px; padding: 9px 18px; text-align: center; color: white; background: var(--primary); border-radius: 5px; }
.menu-toggle { display: none; width: 42px; height: 42px; border: 1px solid var(--line); background: var(--surface); border-radius: 5px; font-size: 21px; }

.hero { border-bottom: 1px solid var(--line); overflow: hidden; }
.hero-inner { min-height: 650px; display: grid; grid-template-columns: minmax(0, 1fr) minmax(430px, 0.88fr); gap: 76px; align-items: center; padding: 52px 0 54px; }
.eyebrow { color: var(--secondary); font-size: 12px; font-weight: 800; letter-spacing: 0; }
.hero h1 { max-width: 610px; margin: 16px 0 20px; font-size: clamp(42px, 4.8vw, 68px); line-height: 1.12; letter-spacing: 0; }
.hero-copy > p { max-width: 610px; margin: 0; color: var(--muted); font-size: 17px; }
.hero-actions { display: flex; align-items: center; gap: 26px; margin-top: 30px; }
.button { display: inline-flex; min-height: 46px; align-items: center; justify-content: center; padding: 10px 25px; border-radius: 5px; font-weight: 800; transition: transform .2s ease, background .2s ease; }
.button:hover { transform: translateY(-2px); }
.button-primary { color: white; background: var(--primary); }
.button-primary:hover { background: var(--primary-dark); }
.text-link { color: var(--secondary); font-weight: 800; }
.hero-tags { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; margin: 34px 0 0; padding: 0; border-block: 1px solid var(--line); list-style: none; }
.hero-tags li { padding: 13px 6px; font-size: 13px; color: var(--muted); }
.hero-tags li + li { border-left: 1px solid var(--line); padding-left: 16px; }
.hero-tags strong { display: block; color: var(--primary-dark); font-size: 11px; }
.hero-media { position: relative; height: 500px; display: flex; align-items: center; justify-content: center; }
.screen { position: absolute; overflow: hidden; border: 1px solid #d5d6da; background: white; box-shadow: 0 18px 50px rgba(36, 28, 31, .14); }
.screen img { width: 100%; height: 100%; object-fit: cover; }
.screen-main { z-index: 2; width: 240px; height: 428px; right: 42px; top: 25px; }
.screen-side { width: 190px; height: 339px; left: 10px; bottom: 24px; opacity: .96; }
.screen-caption { position: absolute; z-index: 3; right: 0; bottom: 2px; width: 208px; display: flex; justify-content: space-between; padding-top: 9px; border-top: 2px solid var(--primary); font-size: 11px; }
.screen-caption strong { color: var(--primary-dark); }

.catalog-strip { background: var(--ink); color: white; }
.catalog-grid { display: grid; grid-template-columns: repeat(3, 1fr); }
.catalog-grid > div { min-height: 94px; display: flex; align-items: center; gap: 15px; padding: 18px 28px; }
.catalog-grid > div + div { border-left: 1px solid #44464b; }
.catalog-grid span { color: #ef9db8; font-size: 12px; font-weight: 800; }
.catalog-grid strong { font-size: 15px; }

.content-section { padding: 82px 0; }
.content-section + .content-section { border-top: 1px solid var(--line); }
.section-heading { display: flex; align-items: baseline; gap: 18px; margin-bottom: 34px; }
.section-heading h2, .task-intro h2 { margin: 0; font-size: 34px; line-height: 1.25; }
.section-index, .article-number { color: var(--primary-dark); font-size: 12px; font-weight: 900; }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); border: 1px solid var(--line); background: var(--surface); }
.feature { min-height: 220px; padding: 28px; }
.feature + .feature { border-left: 1px solid var(--line); }
.feature-wide { grid-column: span 3; min-height: 190px; display: grid; grid-template-columns: 120px minmax(180px, .8fr) 1.4fr; align-items: center; border-bottom: 1px solid var(--line); }
.feature h3 { margin: 15px 0 10px; font-size: 20px; }
.feature p { margin: 0; color: var(--muted); }
.feature-wide h3 { margin: 0; font-size: 28px; }
.feature-code { color: var(--secondary); font-size: 11px; font-weight: 900; }

.gallery-section { background: var(--soft-pink); }
.gallery-grid { display: grid; grid-template-columns: 1fr 1fr 1.2fr; gap: 28px; align-items: end; }
.gallery-item { margin: 0; padding: 20px; border: 1px solid #decbd2; background: rgba(255,255,255,.86); }
.gallery-item img { width: auto; max-width: 100%; max-height: 470px; margin: 0 auto; object-fit: contain; }
.gallery-wide { align-self: center; }
.gallery-wide img { width: 100%; }
.gallery-item figcaption { display: grid; grid-template-columns: 28px 1fr; margin-top: 18px; color: var(--muted); font-size: 13px; }
.gallery-item figcaption span { grid-row: span 2; color: var(--primary-dark); font-weight: 900; }
.gallery-item figcaption strong { display: block; color: var(--ink); font-size: 16px; }

.task-section { background: var(--surface); }
.task-layout { display: grid; grid-template-columns: .8fr 1.4fr; gap: 80px; }
.task-intro .section-note { margin-top: 14px; color: var(--muted); }
.task-links { border-top: 1px solid var(--line); }
.task-links a { display: grid; grid-template-columns: 120px 1fr 32px; gap: 20px; align-items: center; min-height: 96px; border-bottom: 1px solid var(--line); }
.task-links span { color: var(--secondary); font-size: 12px; font-weight: 800; }
.task-links b { color: var(--primary); font-size: 21px; }
.preview-list { border-top: 1px solid var(--line); }
.preview-list a { min-height: 72px; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--line); font-size: 17px; font-weight: 700; }
.preview-list strong { color: var(--primary-dark); font-size: 12px; }

.download-band { padding: 52px 0; color: white; background: var(--secondary); }
.download-inner { display: flex; align-items: center; justify-content: space-between; gap: 30px; }
.download-inner span { color: #c9e1de; font-size: 11px; font-weight: 900; }
.download-inner h2 { margin: 3px 0 0; font-size: 28px; }
.button-light { color: var(--secondary); background: white; }

.site-footer { border-top: 1px solid var(--line); background: #f1f0ed; }
.footer-inner { min-height: 190px; display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 28px 0; text-align: center; }
.footer-brand { display: flex; align-items: center; gap: 10px; }
.footer-inner p { max-width: 760px; margin: 16px auto 8px; color: var(--muted); font-size: 13px; text-align: center; }
.footer-inner small { color: #85868b; text-align: center; }

.sub-hero { border-bottom: 1px solid var(--line); background: var(--surface); }
.sub-hero-inner { min-height: 330px; display: grid; grid-template-columns: 1fr 250px; gap: 70px; align-items: center; }
.sub-hero h1 { margin: 12px 0 16px; font-size: 46px; line-height: 1.2; }
.sub-hero p { max-width: 760px; margin: 0; color: var(--muted); font-size: 17px; }
.sub-hero-index { display: flex; flex-direction: column; align-items: flex-end; padding: 26px 0; border-block: 1px solid var(--line); }
.sub-hero-index strong { color: var(--primary); font-size: 40px; }
.sub-hero-index span { color: var(--muted); font-size: 13px; }
.article-section, .faq-section { padding: 72px 0 90px; }
.article-layout { display: grid; grid-template-columns: 230px minmax(0, 1fr); gap: 70px; align-items: start; }
.article-nav { position: sticky; top: 24px; display: flex; flex-direction: column; border-top: 2px solid var(--ink); }
.article-nav strong { padding: 16px 0 12px; color: var(--secondary); font-size: 11px; }
.article-nav a { padding: 10px 0; border-bottom: 1px solid var(--line); color: var(--muted); font-size: 14px; }
.article-body > section { position: relative; padding: 0 0 52px 64px; }
.article-body > section + section { padding-top: 52px; border-top: 1px solid var(--line); }
.article-number { position: absolute; left: 0; top: 8px; }
.article-body h2 { margin: 0 0 18px; font-size: 28px; }
.article-body p { color: #4f5158; }
.article-body code { padding: 2px 6px; background: var(--soft-green); border-radius: 3px; }
.article-body a { color: var(--primary-dark); text-decoration: underline; }
.callout { margin: 24px 0; padding: 20px 24px; border-left: 3px solid var(--secondary); background: var(--soft-green); }
.callout p { margin-bottom: 0; }
.article-action, .faq-bottom { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 30px; background: var(--soft-pink); }
.article-action span { color: var(--primary-dark); font-size: 11px; font-weight: 900; }
.article-action h2 { margin: 4px 0 0; }

.faq-layout { max-width: 950px; }
.faq-filter { display: flex; gap: 8px; margin-bottom: 24px; }
.faq-filter button { padding: 8px 18px; border: 1px solid var(--line); background: var(--surface); border-radius: 4px; cursor: pointer; }
.faq-filter button.is-active { color: white; background: var(--secondary); border-color: var(--secondary); }
.faq-list { border-top: 1px solid var(--line); }
.faq-item { border-bottom: 1px solid var(--line); }
.faq-item > button { width: 100%; min-height: 78px; display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 14px 0; border: 0; color: var(--ink); background: transparent; text-align: left; cursor: pointer; }
.faq-item > button span { font-size: 17px; font-weight: 800; }
.faq-item > button b { display: inline-block; width: 35px; color: var(--primary-dark); font-size: 11px; }
.faq-item > button i { color: var(--primary); font-size: 25px; font-style: normal; transition: transform .2s ease; }
.faq-item > div { display: none; padding: 0 52px 24px 35px; color: var(--muted); }
.faq-item > div p { margin: 0; }
.faq-item.is-open > div { display: block; }
.faq-item.is-open > button i { transform: rotate(45deg); }
.faq-item.is-hidden { display: none; }
.faq-bottom { margin-top: 42px; }
.faq-bottom div { display: flex; flex-direction: column; }
.faq-bottom span { color: var(--primary-dark); font-size: 12px; }

@media (max-width: 900px) {
  .header-inner, .section-inner, .hero-inner, .footer-inner { width: min(calc(100% - 32px), var(--max)); }
  .menu-toggle { display: inline-grid; place-items: center; }
  .site-nav { position: absolute; top: 74px; left: 16px; right: 16px; display: none; flex-direction: column; align-items: stretch; gap: 0; padding: 12px; border: 1px solid var(--line); background: var(--surface); box-shadow: 0 18px 40px rgba(20,20,22,.12); }
  .site-nav.is-open { display: flex; }
  .site-nav > a:not(.nav-download), .nav-download { padding: 12px; border: 0; text-align: left; }
  .hero-inner { min-height: auto; grid-template-columns: 1fr; gap: 34px; padding: 42px 0 52px; }
  .hero h1 { font-size: clamp(38px, 10vw, 52px); }
  .hero-media { height: 440px; max-width: 480px; width: 100%; margin-inline: auto; }
  .screen-main { right: 12%; width: 210px; height: 375px; }
  .screen-side { left: 7%; width: 168px; height: 300px; }
  .catalog-grid { grid-template-columns: 1fr; }
  .catalog-grid > div + div { border-left: 0; border-top: 1px solid #44464b; }
  .feature-grid { grid-template-columns: 1fr; }
  .feature, .feature-wide { grid-column: auto; display: block; min-height: auto; }
  .feature + .feature { border-left: 0; border-top: 1px solid var(--line); }
  .feature-wide h3 { margin: 15px 0 10px; font-size: 22px; }
  .gallery-grid { grid-template-columns: 1fr 1fr; }
  .gallery-wide { grid-column: span 2; }
  .task-layout, .article-layout { grid-template-columns: 1fr; gap: 35px; }
  .article-nav { position: static; display: grid; grid-template-columns: repeat(3, 1fr); }
  .article-nav strong { grid-column: 1 / -1; }
  .sub-hero-inner { grid-template-columns: 1fr; gap: 24px; padding: 48px 0; }
  .sub-hero-index { align-items: flex-start; }
}

@media (max-width: 560px) {
  .header-inner, .section-inner, .hero-inner, .footer-inner { width: min(calc(100% - 28px), var(--max)); }
  .brand { font-size: 16px; }
  .hero-inner { gap: 16px; padding: 24px 0 26px; }
  .hero h1 { margin: 9px 0 12px; font-size: 36px; }
  .hero-copy > p { font-size: 14px; line-height: 1.65; }
  .hero-actions { flex-direction: row; gap: 12px; margin-top: 18px; }
  .hero-actions .button { min-height: 42px; padding: 8px 18px; }
  .hero-actions .text-link { align-self: center; font-size: 13px; }
  .hero-tags { grid-template-columns: repeat(3, 1fr); margin-top: 20px; }
  .hero-tags li { padding: 8px 4px; font-size: 12px; }
  .hero-tags li + li { border-top: 0; border-left: 1px solid var(--line); padding-left: 10px; }
  .hero-media { height: 210px; }
  .screen-main { top: 0; right: 9%; width: 118px; height: 210px; }
  .screen-side { left: 12%; bottom: 0; width: 94px; height: 168px; }
  .screen-caption { right: 3%; bottom: -8px; width: 118px; font-size: 9px; }
  .content-section { padding: 58px 0; }
  .section-heading h2, .task-intro h2 { font-size: 28px; }
  .gallery-grid { grid-template-columns: 1fr; }
  .gallery-wide { grid-column: auto; }
  .task-links a { grid-template-columns: 80px 1fr 20px; }
  .download-inner, .article-action, .faq-bottom { align-items: flex-start; flex-direction: column; }
  .sub-hero h1 { font-size: 35px; }
  .article-nav { grid-template-columns: 1fr 1fr; }
  .article-body > section { padding-left: 35px; }
  .faq-item > button span { font-size: 15px; }
  .faq-item > div { padding-left: 35px; padding-right: 10px; }
}

/* Filmstrip variant for this project. */
:root {
  --primary: #287a73;
  --primary-dark: #1d5d58;
  --secondary: #bc4e5c;
  --soft-pink: #f6e9e7;
  --soft-green: #e5f0ed;
}

.hero-inner { grid-template-columns: minmax(0, .88fr) minmax(520px, 1.12fr); }
.hero-media { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; align-items: center; }
.screen-main, .screen-side, .screen-third { position: relative; inset: auto; width: 100%; opacity: 1; }
.screen-main { height: 390px; }
.screen-side { height: 330px; }
.screen-third { height: 360px; }
.screen img { object-fit: cover; }
.screen-caption { right: 0; bottom: -2px; width: 100%; }
.catalog-strip { background: #244743; }
.gallery-section { background: var(--soft-green); }
.download-band { background: var(--primary-dark); }

@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero-media { height: 430px; }
}

@media (max-width: 560px) {
  .hero-media { height: 205px; gap: 8px; }
  .screen-main { height: 185px; }
  .screen-side { height: 150px; }
  .screen-third { height: 170px; }
  .screen-caption { right: 0; bottom: -9px; width: 100%; }
}