/* 51视频 — original visual system */
:root {
  --ink: #10233f;
  --ink-soft: #173653;
  --night: #0a172d;
  --cream: #fffaf2;
  --paper: #f4f7f9;
  --sand: #f7f0e4;
  --line: #d9e2e8;
  --muted: #607183;
  --cyan: #1bc6d4;
  --cyan-dark: #07869b;
  --orange: #ff8755;
  --orange-light: #ffc267;
  --violet: #7657ee;
  --shadow: 0 18px 45px rgba(16, 35, 63, .13);
  --wrap: min(1160px, calc(100% - 40px));
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 16px/1.72 "Noto Sans SC", "Microsoft YaHei", system-ui, sans-serif; }
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, input { font: inherit; }
button { cursor: pointer; }
.wrap { width: var(--wrap); margin-inline: auto; }
.sr-only { position: absolute; overflow: hidden; width: 1px; height: 1px; clip: rect(0, 0, 0, 0); white-space: nowrap; }
.skip-link { position: fixed; top: -5rem; left: 1rem; z-index: 100; padding: .6rem 1rem; background: var(--cyan); color: var(--night); border-radius: 0 0 .6rem .6rem; font-weight: 800; }
.skip-link:focus { top: 0; }
.announcement { color: rgba(255,255,255,.78); background: var(--night); font-size: .76rem; }
.announcement__inner { display: flex; justify-content: space-between; gap: 1rem; padding: .38rem 0; }
.announcement a { color: #95eff4; }
.site-header { position: relative; z-index: 20; background: var(--cream); box-shadow: 0 2px 12px rgba(16,35,63,.04); }
.nav-shell { min-height: 86px; display: flex; align-items: center; gap: 2rem; }
.brand { display: inline-flex; align-items: center; flex: 0 0 auto; gap: .62rem; }
.brand img { width: 48px; height: 48px; object-fit: contain; }
.brand span { display: grid; line-height: 1; }
.brand b { font-size: 1.25rem; letter-spacing: .06em; }
.brand small { margin-top: .4rem; color: var(--cyan-dark); font-size: .52rem; font-weight: 900; letter-spacing: .15em; }
.site-nav { display: flex; align-items: center; justify-content: flex-end; gap: 1.2rem; width: 100%; }
.site-nav a { position: relative; padding: .45rem 0; color: #3f5369; font-size: .86rem; font-weight: 800; white-space: nowrap; }
.site-nav a::after { position: absolute; right: 0; bottom: 0; left: 0; height: 2px; background: var(--orange); content: ""; transform: scaleX(0); transform-origin: right; transition: transform .2s ease; }
.site-nav a:hover, .site-nav a.is-current { color: var(--ink); }
.site-nav a:hover::after, .site-nav a.is-current::after { transform: scaleX(1); transform-origin: left; }
.nav-toggle { display: none; width: 43px; height: 43px; margin-left: auto; border: 1px solid var(--line); border-radius: 10px; background: #fff; }
.nav-toggle i { display: block; width: 19px; height: 2px; margin: 4px auto; background: var(--ink); }
.search-ribbon { color: #dfefff; background: var(--ink-soft); }
.search-ribbon__inner { display: grid; grid-template-columns: minmax(260px, 520px) 1fr; align-items: center; gap: 1.4rem; min-height: 58px; }
.demo-search { display: flex; align-items: center; overflow: hidden; height: 36px; border: 1px solid rgba(255,255,255,.22); border-radius: 8px; background: rgba(255,255,255,.08); }
.demo-search > span { padding: 0 .7rem 0 .9rem; font-size: 1.5rem; line-height: 0; }
.demo-search input { min-width: 0; flex: 1; height: 100%; border: 0; outline: 0; background: transparent; color: #fff; font-size: .78rem; }
.demo-search input::placeholder { color: rgba(255,255,255,.64); }
.demo-search button { height: 100%; border: 0; padding: 0 .9rem; color: var(--night); background: var(--cyan); font-size: .76rem; font-weight: 900; }
#search-result { margin: 0; font-size: .75rem; }
#search-result a { margin-left: .8rem; color: #8eeaf0; font-weight: 800; }
.breadcrumb { display: flex; align-items: center; gap: .55rem; min-height: 51px; color: var(--muted); font-size: .77rem; }
.breadcrumb a { color: var(--cyan-dark); font-weight: 800; }
.breadcrumb strong { color: var(--ink); font-weight: 800; }
.hero { position: relative; overflow: hidden; padding: 5.8rem 0 0; color: #fff; background: linear-gradient(115deg, var(--night), var(--ink-soft) 58%, #173d5c); }
.hero::before { position: absolute; width: 500px; height: 500px; right: -160px; bottom: -250px; border-radius: 50%; background: var(--orange); content: ""; filter: blur(1px); opacity: .88; }
.hero__grid { position: relative; display: grid; grid-template-columns: 1fr .91fr; align-items: center; gap: 3.5rem; }
.eyebrow { display: flex; align-items: center; gap: .65rem; margin: 0 0 1rem; color: var(--cyan-dark); font-size: .72rem; font-weight: 900; letter-spacing: .12em; text-transform: uppercase; }
.eyebrow::before { width: 24px; height: 2px; content: ""; background: currentColor; }
.eyebrow--light { color: #87edf1; }
.hero h1 { margin: 0; font-size: clamp(2.7rem, 5.4vw, 5.1rem); line-height: 1.05; letter-spacing: -.065em; }
.hero h1 span { color: var(--orange-light); font-style: normal; }
.hero__copy > p:not(.eyebrow) { max-width: 580px; margin: 1.65rem 0 2rem; color: rgba(255,255,255,.78); font-size: 1rem; }
.hero__copy strong { color: #fff0b8; }
.hero-actions { display: flex; flex-wrap: wrap; gap: .75rem; }
.button { display: inline-flex; justify-content: center; align-items: center; min-height: 46px; padding: 0 1.12rem; border: 1px solid transparent; border-radius: 8px; font-size: .85rem; font-weight: 900; transition: transform .2s ease, box-shadow .2s ease, background .2s ease; }
.button:hover { transform: translateY(-3px); box-shadow: 0 12px 24px rgba(0,0,0,.18); }
.button--bright { color: var(--night); background: var(--cyan); }
.button--ghost { color: #fff; border-color: rgba(255,255,255,.45); background: rgba(255,255,255,.08); }
.button--dark { color: #fff; background: var(--ink); }
.hero-points { display: flex; flex-wrap: wrap; gap: 1.15rem; padding: 0; margin: 1.8rem 0 0; list-style: none; color: rgba(255,255,255,.72); font-size: .78rem; }
.hero-points li::before { margin-right: .36rem; color: var(--cyan); content: "◆"; }
.hero__art { position: relative; align-self: end; margin-bottom: 2rem; }
.hero__art img { position: relative; width: 100%; min-height: 410px; border-radius: 28px 28px 8px 28px; object-fit: cover; box-shadow: 20px 20px 0 rgba(255,255,255,.08); }
.hero-stamp { position: absolute; right: -1.5rem; bottom: 1.25rem; display: flex; align-items: center; gap: .5rem; padding: .62rem .8rem; border-radius: 10px; color: var(--night); background: var(--cream); box-shadow: var(--shadow); }
.hero-stamp b { color: var(--orange); font-size: 2rem; line-height: 1; }
.hero-stamp span { font-size: .56rem; font-weight: 900; letter-spacing: .12em; line-height: 1.3; }
.signal-strip { position: relative; display: grid; grid-template-columns: repeat(4, 1fr); margin-top: 3.4rem; border: 1px solid rgba(255,255,255,.13); border-bottom: 0; border-radius: 12px 12px 0 0; background: rgba(6,18,37,.36); backdrop-filter: blur(8px); }
.signal-strip div { padding: 1.15rem 1.25rem; border-right: 1px solid rgba(255,255,255,.13); }
.signal-strip div:last-child { border-right: 0; }
.signal-strip b, .signal-strip span { display: block; }
.signal-strip b { color: #fff; font-size: .92rem; }
.signal-strip span { color: rgba(255,255,255,.57); font-size: .7rem; }
.topic-rail { border-bottom: 1px solid var(--line); background: #fff; }
.topic-rail .wrap { display: flex; flex-wrap: wrap; align-items: center; gap: .55rem; padding: .88rem 0; }
.topic-rail b { margin-right: .5rem; color: var(--ink); font-size: .77rem; }
.topic-rail a { padding: .25rem .65rem; border: 1px solid var(--line); border-radius: 999px; color: var(--muted); font-size: .72rem; font-weight: 800; }
.topic-rail a:hover { border-color: var(--cyan); color: var(--cyan-dark); }
.section { position: relative; padding: 5.7rem 0; }
.section--ink { overflow: hidden; color: #fff; background: var(--ink); }
.section--ink::after { position: absolute; z-index: 0; right: -140px; bottom: -140px; width: 340px; height: 340px; border: 48px solid var(--cyan); border-radius: 50%; content: ""; opacity: .12; }
.section--sand { background: var(--sand); }
.section > .wrap { position: relative; z-index: 1; }
.section-title { max-width: 720px; margin-bottom: 2.4rem; }
.section-title--center { margin-inline: auto; text-align: center; }
.section-title--center .eyebrow { justify-content: center; }
.section-title h2, .split-head h2, .feature-copy h2, .community-copy h2, .note-layout h2, .howto-layout h2, .contact-layout h2 { margin: 0; font-size: clamp(2rem, 3.8vw, 3.25rem); letter-spacing: -.055em; line-height: 1.12; }
.section-title h2 span, .split-head h2 span, .feature-copy h2 span, .note-layout h2 span, .howto-layout h2 span, .contact-layout h2 span { color: var(--orange); }
.section-title > p:last-child { margin: 1.1rem 0 0; color: var(--muted); font-size: .94rem; }
.video-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.35rem; }
.video-card { overflow: hidden; border-radius: 13px; background: #fff; box-shadow: 0 7px 18px rgba(16,35,63,.07); cursor: pointer; transition: transform .25s ease, box-shadow .25s ease; }
.video-card:hover, .video-card:focus-visible { transform: translateY(-7px); outline: 0; box-shadow: var(--shadow); }
.card-visual { position: relative; overflow: hidden; aspect-ratio: 16 / 10; background: var(--ink); }
.card-visual img { width: 100%; height: 100%; object-fit: cover; transition: transform .6s ease; }
.video-card:hover .card-visual img { transform: scale(1.06); }
.card-visual::after { position: absolute; inset: 0; background: linear-gradient(180deg, transparent 42%, rgba(7,18,37,.72)); content: ""; }
.card-tag, .card-duration, .play-button { position: absolute; z-index: 2; }
.card-tag { top: .75rem; left: .75rem; padding: .22rem .55rem; border-radius: 4px; color: var(--night); background: var(--cyan); font-size: .67rem; font-weight: 900; }
.card-duration { right: .75rem; bottom: .72rem; padding: .13rem .38rem; border-radius: 3px; color: #fff; background: rgba(7,18,37,.78); font-size: .65rem; font-weight: 800; }
.play-button { display: grid; place-items: center; left: 50%; top: 50%; width: 53px; height: 53px; border: 2px solid rgba(255,255,255,.85); border-radius: 50%; color: #fff; font-size: 1.15rem; transform: translate(-50%, -40%) scale(.7); opacity: 0; transition: transform .2s ease, opacity .2s ease; }
.video-card:hover .play-button, .video-card:focus-visible .play-button { transform: translate(-50%, -50%) scale(1); opacity: 1; }
.card-body { padding: 1.05rem 1.15rem 1.18rem; }
.card-body > p:first-child { margin: 0; color: var(--cyan-dark); font-size: .67rem; font-weight: 900; }
.card-body h3 { margin: .45rem 0 .45rem; font-size: 1.02rem; line-height: 1.44; }
.card-body > p:nth-of-type(2) { min-height: 3.25rem; margin: 0; color: var(--muted); font-size: .77rem; }
.card-body small { display: block; margin-top: .75rem; color: #8a9aa6; font-size: .66rem; }
.split-head { display: grid; grid-template-columns: 1.1fr .9fr; align-items: end; gap: 3rem; margin-bottom: 2.3rem; }
.split-head h2 { color: #fff; }
.split-head > p { margin: 0; color: rgba(255,255,255,.63); font-size: .88rem; }
.studio-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.studio-grid article { min-height: 225px; padding: 1.45rem; border: 1px solid rgba(255,255,255,.15); border-radius: 10px; background: rgba(255,255,255,.045); transition: background .2s ease, transform .2s ease; }
.studio-grid article:hover { background: rgba(255,255,255,.11); transform: translateY(-4px); }
.studio-grid span { color: var(--cyan); font-size: .7rem; font-weight: 900; letter-spacing: .14em; }
.studio-grid h3 { margin: 1rem 0 .5rem; font-size: 1.2rem; }
.studio-grid p { margin: 0; color: rgba(255,255,255,.66); font-size: .77rem; }
.studio-grid a { display: inline-block; margin-top: 1rem; color: var(--orange-light); font-size: .73rem; font-weight: 900; }
.feature-layout { display: grid; grid-template-columns: .9fr 1.1fr; align-items: center; gap: 4rem; }
.feature-photo { position: relative; }
.feature-photo img { width: 100%; min-height: 470px; border-radius: 16px; object-fit: cover; box-shadow: var(--shadow); }
.feature-photo div { position: absolute; right: -1.4rem; bottom: 1.8rem; padding: 1rem 1.2rem; border-radius: 10px; color: #fff; background: var(--violet); box-shadow: var(--shadow); }
.feature-photo b, .feature-photo span { display: block; }
.feature-photo b { font-size: 1.26rem; }
.feature-photo span { font-size: .68rem; opacity: .75; }
.feature-copy > p:not(.eyebrow) { color: var(--muted); font-size: .91rem; }
.number-list { display: grid; gap: 1rem; padding: 0; margin: 1.8rem 0 0; list-style: none; counter-reset: list; }
.number-list li { display: grid; grid-template-columns: 1fr; padding: .95rem 0 .95rem 3.2rem; border-top: 1px solid var(--line); position: relative; }
.number-list li::before { position: absolute; left: 0; top: 1rem; color: var(--orange); content: "0" counter(list); counter-increment: list; font-size: 1.1rem; font-weight: 900; }
.number-list b { font-size: .94rem; }
.number-list span { color: var(--muted); font-size: .76rem; }
.community-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.community-grid article { min-height: 193px; padding: 1.35rem; border: 1px solid #eadfcf; border-radius: 11px; background: rgba(255,255,255,.62); }
.community-grid__visual { grid-row: span 2; padding: 0 !important; overflow: hidden; }
.community-grid__visual img { width: 100%; height: 100%; object-fit: cover; }
.community-grid b { display: grid; place-items: center; width: 34px; height: 34px; border-radius: 50%; color: var(--night); background: var(--orange-light); font-size: .75rem; }
.community-grid h3 { margin: .85rem 0 .3rem; font-size: 1rem; }
.community-grid p { margin: 0; color: var(--muted); font-size: .75rem; }
.expert-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; }
.expert-grid article { padding: 1.3rem; border-radius: 11px; background: #fff; box-shadow: 0 7px 18px rgba(16,35,63,.06); }
.avatar { display: grid; place-items: center; width: 48px; height: 48px; border-radius: 50%; color: #fff; background: linear-gradient(135deg, var(--ink), var(--violet)); font-weight: 900; }
.expert-grid h3 { margin: .9rem 0 .35rem; font-size: 1.03rem; }
.expert-grid > article > p { min-height: 3.2rem; margin: 0; color: var(--muted); font-size: .74rem; }
.expert-grid ul { min-height: 4.5rem; padding-left: 1rem; color: #51647a; font-size: .69rem; }
.expert-grid a { display: block; padding: .4rem 0; border-top: 1px solid var(--line); color: var(--cyan-dark); font-size: .72rem; font-weight: 900; }
.how-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; }
.how-grid article { padding: 1.3rem; border-radius: 10px; color: var(--ink); background: #fff; }
.how-grid span { color: var(--orange); font-size: 1.1rem; font-weight: 900; }
.how-grid h3 { margin: .8rem 0 .4rem; font-size: .98rem; }
.how-grid p { margin: 0; color: var(--muted); font-size: .75rem; }
.howto-layout { display: grid; grid-template-columns: 1fr .9fr; align-items: center; gap: 4.5rem; }
.howto-layout > img { min-height: 475px; border-radius: 14px; object-fit: cover; box-shadow: var(--shadow); }
.howto-layout > div > p:not(.eyebrow) { color: var(--muted); font-size: .88rem; }
.steps { display: grid; gap: .2rem; margin-top: 1.4rem; }
.steps article { display: grid; grid-template-columns: 34px 1fr; gap: .9rem; align-items: start; padding: .8rem 0; border-bottom: 1px solid var(--line); }
.steps b { display: grid; place-items: center; width: 31px; height: 31px; border-radius: 50%; color: #fff; background: var(--orange); font-size: .77rem; }
.steps h3 { margin: 0; font-size: .94rem; }
.steps p { margin: .12rem 0 0; color: var(--muted); font-size: .75rem; }
.faq-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: .7rem 1.5rem; }
details { border-bottom: 1px solid var(--line); background: rgba(255,255,255,.28); }
summary { position: relative; padding: 1rem 2rem 1rem 0; cursor: pointer; font-size: .89rem; font-weight: 900; list-style: none; }
summary::after { position: absolute; right: .15rem; color: var(--orange); content: "+"; font-size: 1.35rem; }
details[open] summary::after { content: "−"; }
details p { margin: 0 0 1rem; color: var(--muted); font-size: .76rem; }
.review-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; }
.review-grid article { padding: 1.25rem; border-left: 3px solid var(--cyan); background: #fff; box-shadow: 0 6px 14px rgba(16,35,63,.04); }
.review-grid div { color: var(--cyan-dark); font-size: .68rem; font-weight: 900; }
.review-grid blockquote { min-height: 6rem; margin: .9rem 0; color: var(--ink); font-size: .85rem; line-height: 1.75; }
.review-grid p { margin: 0; color: var(--muted); font-size: .67rem; }
.section--contact { color: #fff; background: linear-gradient(135deg, var(--night), #17435b); }
.contact-layout { display: grid; grid-template-columns: 1.08fr .92fr; align-items: center; gap: 3.4rem; }
.contact-layout h2 span { color: var(--cyan); }
.contact-layout > div > p:not(.eyebrow) { color: rgba(255,255,255,.7); font-size: .88rem; }
.contact-table { display: grid; margin-top: 1.4rem; border-top: 1px solid rgba(255,255,255,.14); }
.contact-table div { display: grid; grid-template-columns: 118px 1fr; gap: 1rem; padding: .7rem 0; border-bottom: 1px solid rgba(255,255,255,.14); font-size: .74rem; }
.contact-table b { color: var(--cyan); }
.contact-table span { color: rgba(255,255,255,.76); }
.contact-table a { color: #fff0b8; }
.contact-layout aside { position: relative; overflow: hidden; min-height: 460px; border-radius: 15px; }
.contact-layout aside img { width: 100%; height: 100%; min-height: 460px; object-fit: cover; }
.contact-layout aside > div { position: absolute; right: 0; bottom: 0; left: 0; padding: 1.25rem; background: linear-gradient(transparent, rgba(6,16,30,.94) 35%); }
.contact-layout aside b { font-size: 1.1rem; }
.contact-layout aside ul { margin: .65rem 0 0; padding-left: 1rem; color: rgba(255,255,255,.76); font-size: .73rem; }
.subhero { overflow: hidden; padding: 3.8rem 0; background: linear-gradient(135deg, #e7f6f8, #fff0dd); }
.subhero__grid { display: grid; grid-template-columns: 1.05fr .95fr; align-items: center; gap: 3rem; }
.subhero h1 { max-width: 650px; margin: 0; font-size: clamp(2.5rem, 5vw, 4.4rem); line-height: 1.08; letter-spacing: -.065em; }
.subhero > div > div > p:not(.eyebrow) { max-width: 600px; color: #50657a; }
.subhero__grid > img { min-height: 290px; border-radius: 12px; object-fit: cover; box-shadow: 12px 12px 0 rgba(27,198,212,.22); }
.note-layout { display: grid; grid-template-columns: .9fr 1.1fr; align-items: center; gap: 4rem; }
.note-layout > img { min-height: 420px; border-radius: 14px; object-fit: cover; box-shadow: var(--shadow); }
.note-layout > div > p:not(.eyebrow) { color: var(--muted); }
.check-list { display: grid; gap: .65rem; padding: 0; margin: 1.5rem 0; list-style: none; color: #425a6e; font-size: .8rem; }
.check-list li::before { margin-right: .5rem; color: var(--cyan-dark); content: "✓"; font-weight: 900; }
.site-footer { color: rgba(255,255,255,.72); background: #071326; }
.footer-grid { display: grid; grid-template-columns: 1.55fr .85fr .85fr 1.15fr; gap: 2rem; padding: 4rem 0 2.3rem; }
.brand--footer b { color: #fff; }
.footer-intro p { max-width: 370px; font-size: .74rem; }
.share-row { display: flex; flex-wrap: wrap; gap: .45rem; }
.share-row button { border: 1px solid rgba(255,255,255,.22); border-radius: 4px; padding: .32rem .54rem; color: #dcecf3; background: transparent; font-size: .65rem; }
.share-row button:hover { border-color: var(--cyan); color: var(--cyan); }
.footer-links { display: grid; align-content: start; gap: .52rem; }
.footer-links h2 { margin: 0 0 .35rem; color: #fff; font-size: .82rem; }
.footer-links a { color: rgba(255,255,255,.65); font-size: .72rem; }
.footer-links a:hover { color: var(--cyan); }
.qr-area { display: flex; align-items: start; gap: .9rem; }
.qr-area div { width: 96px; text-align: center; }
.qr-area img { width: 86px; height: 86px; padding: 4px; margin-inline: auto; background: #fff; }
.qr-area span { display: block; margin-top: .4rem; color: rgba(255,255,255,.6); font-size: .6rem; }
.footer-bottom { display: flex; justify-content: space-between; gap: 1rem; padding: 1rem 0; border-top: 1px solid rgba(255,255,255,.13); color: rgba(255,255,255,.43); font-size: .67rem; }
.video-dialog { width: min(620px, calc(100% - 32px)); overflow: hidden; padding: 0; border: 0; border-radius: 15px; box-shadow: 0 30px 80px rgba(0,0,0,.45); }
.video-dialog::backdrop { background: rgba(5,12,25,.73); backdrop-filter: blur(5px); }
.dialog-screen { display: grid; place-items: center; min-height: 255px; color: #fff; background: radial-gradient(circle at center, var(--violet), var(--ink) 63%); font-size: 2rem; }
.dialog-screen span { display: grid; place-items: center; width: 70px; height: 70px; border: 2px solid rgba(255,255,255,.85); border-radius: 50%; }
.dialog-copy { padding: 1.35rem 1.5rem 1.6rem; background: #fff; }
.dialog-copy h2 { margin: 0 0 .3rem; font-size: 1.4rem; }
.dialog-copy p:last-child { margin: 0; color: var(--muted); font-size: .78rem; }
.dialog-close { position: absolute; z-index: 2; top: .65rem; right: .65rem; width: 34px; height: 34px; border: 0; border-radius: 50%; color: var(--ink); background: #fff; font-size: 1.35rem; }
@media (max-width: 1020px) {
  .site-nav { gap: .75rem; }
  .site-nav a { font-size: .74rem; }
  .hero__grid, .feature-layout, .howto-layout, .contact-layout, .note-layout { gap: 2.2rem; }
  .expert-grid { grid-template-columns: repeat(2, 1fr); }
  .review-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1.3fr 1fr 1fr; }
  .qr-area { grid-column: span 2; }
}
@media (max-width: 780px) {
  :root { --wrap: min(100% - 30px, 1160px); }
  .announcement__inner { font-size: .67rem; }
  .nav-shell { min-height: 72px; }
  .nav-toggle { display: block; }
  .site-nav { position: absolute; top: 100%; right: 0; left: 0; display: none; padding: 1rem 15px; border-top: 1px solid var(--line); background: var(--cream); box-shadow: 0 10px 16px rgba(16,35,63,.08); }
  .site-nav.is-open { display: grid; gap: .3rem; }
  .site-nav a { padding: .65rem 0; font-size: .88rem; }
  .site-nav a::after { display: none; }
  .search-ribbon__inner { grid-template-columns: 1fr; gap: .45rem; padding: .6rem 0; }
  #search-result { line-height: 1.9; }
  .hero { padding-top: 3.8rem; }
  .hero__grid, .subhero__grid, .feature-layout, .howto-layout, .contact-layout, .note-layout { grid-template-columns: 1fr; }
  .hero__art { margin-bottom: 0; }
  .hero__art img { min-height: 260px; }
  .signal-strip { grid-template-columns: repeat(2, 1fr); margin-top: 2.5rem; }
  .signal-strip div:nth-child(2) { border-right: 0; }
  .signal-strip div:nth-child(-n+2) { border-bottom: 1px solid rgba(255,255,255,.13); }
  .section { padding: 4rem 0; }
  .video-grid, .studio-grid { grid-template-columns: repeat(2, 1fr); }
  .split-head { grid-template-columns: 1fr; gap: 1rem; }
  .community-grid { grid-template-columns: repeat(2, 1fr); }
  .community-grid__visual { grid-column: span 2; grid-row: auto; min-height: 240px !important; }
  .how-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-photo img, .howto-layout > img, .note-layout > img { min-height: 320px; }
  .feature-photo div { right: .7rem; }
  .contact-layout aside, .contact-layout aside img { min-height: 310px; }
}
@media (max-width: 520px) {
  .announcement__inner { align-items: center; }
  .announcement__inner a { display: none; }
  .brand b { font-size: 1.08rem; }
  .breadcrumb { min-height: 43px; font-size: .68rem; }
  .hero h1, .subhero h1 { font-size: 2.55rem; }
  .hero-actions .button { width: 100%; }
  .signal-strip { width: 100%; }
  .signal-strip div { padding: .95rem; }
  .topic-rail .wrap { gap: .4rem; }
  .section-title h2, .split-head h2, .feature-copy h2, .note-layout h2, .howto-layout h2, .contact-layout h2 { font-size: 2rem; }
  .video-grid, .studio-grid, .community-grid, .expert-grid, .how-grid, .review-grid, .faq-grid { grid-template-columns: 1fr; }
  .community-grid__visual { grid-column: auto; min-height: 230px !important; }
  .card-body > p:nth-of-type(2), .expert-grid > article > p, .review-grid blockquote { min-height: auto; }
  .howto-layout, .contact-layout, .note-layout { gap: 1.7rem; }
  .subhero { padding: 2.8rem 0; }
  .subhero__grid > img { min-height: 220px; }
  .contact-table div { grid-template-columns: 1fr; gap: .1rem; }
  .footer-grid { grid-template-columns: 1fr; padding-top: 3rem; }
  .qr-area { grid-column: auto; }
  .footer-bottom { flex-direction: column; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; animation-duration: .01ms !important; }
}

/* Branded hero subtitle */
.hero-subtitle { margin: .8rem 0 .25rem !important; color: var(--cyan) !important; font-size: .82rem !important; font-weight: 900; letter-spacing: .08em; }