/* Hailong AIoT V28 — shared typography and compact cards */
:root {
  --text: #102845;
  --muted: #60758c;
  --blue: #1677ed;
  --cyan: #49c9ff;
  --yijia-bg: #edf6fd;
  --card-radius: 6px;
  --section-title: clamp(26px, 3vw, 40px);
  --body-size: 15px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 92px; }
body { margin: 0; font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif; background: #fff; color: var(--text); font-size: var(--body-size); }
button { font: inherit; }
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button, a { -webkit-tap-highlight-color: transparent; }
button:focus-visible, a:focus-visible, [tabindex="0"]:focus-visible { outline: 2px solid var(--blue); outline-offset: 4px; }
.aiot-page { overflow: clip; }
.ai-width { width: min(1200px, calc(100% - 64px)); margin: 0 auto; }

/* Navigation */
.ai-header { position: fixed; inset: 0 0 auto; z-index: 30; height: 76px; display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 0 clamp(24px, 4vw, 72px); background: linear-gradient(180deg, rgba(4,16,29,.92), rgba(4,16,29,.5), transparent); transition: background .3s; }
.ai-header.is-solid { background: rgba(4,16,29,.95); backdrop-filter: blur(10px); }
.ai-header-brand { flex-shrink: 0; }
.ai-header-brand img { width: 176px; }
.ai-header-links { display: flex; gap: clamp(16px, 2vw, 30px); color: rgba(255,255,255,.85); align-items: center; font-size: 14px; }
.ai-header-links a { position: relative; padding: 10px 0; white-space: nowrap; }
.ai-header-links a.active, .ai-header-links a:hover { color: #fff; }
.ai-header-links a.active::after, .ai-header-links a:hover::after { content: ""; position: absolute; inset: auto 0 0; height: 2px; background: var(--cyan); }
.ai-header-tools { display: flex; align-items: center; gap: 18px; }
.ai-back-link { padding: 9px 14px; border: 1px solid rgba(255,255,255,.25); border-radius: var(--card-radius); color: #fff; font-size: 12px; white-space: nowrap; }
.ai-menu-btn { display: none; width: 42px; height: 42px; border: 1px solid rgba(255,255,255,.25); border-radius: var(--card-radius); background: rgba(255,255,255,.06); color: #fff; font-size: 22px; cursor: pointer; }
.ai-mobile-menu { position: fixed; top: 74px; right: 20px; z-index: 29; display: none; flex-direction: column; min-width: 220px; padding: 10px; border-radius: var(--card-radius); background: #071a30; box-shadow: 0 12px 32px #00132630; }
.ai-mobile-menu.open { display: flex; }
.ai-mobile-menu a { color: #fff; padding: 12px 14px; font-size: 14px; border-radius: 4px; }
.ai-mobile-menu a:hover { background: #ffffff10; }
.ai-side-progress { position: fixed; right: 18px; top: 50%; transform: translateY(-50%); z-index: 28; display: flex; flex-direction: column; gap: 10px; }
.ai-side-progress a { position: relative; padding: 6px 0 6px 14px; font-size: 11px; color: #5e7995; }
.ai-side-progress a::before { content: ""; position: absolute; left: 0; top: 50%; transform: translateY(-50%); width: 6px; height: 6px; border-radius: 50%; border: 1px solid currentColor; }
.ai-side-progress a.selected { color: var(--blue); }
.ai-side-progress a.selected::before { background: currentColor; }
.ai-side-progress.is-on-dark a { color: #ffffffa6; }
.ai-side-progress.is-on-dark a.selected { color: #fff; }

/* Video sections and shared heading hierarchy */
.ai-video-section { position: relative; min-height: 100vh; min-height: 100svh; display: grid; place-items: center; overflow: hidden; color: #fff; }
.ai-bg-video, .ai-video-fallback { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.ai-video-fallback { background: center / cover no-repeat; }
.ai-video-shade { position: absolute; inset: 0; background: linear-gradient(180deg, #03091666, #040b18ad 50%, #030916db); }
.ai-video-shade--blue { background: radial-gradient(circle at center, #3fb4ff18, transparent 45%), linear-gradient(180deg, #02102680, #040f2bbb 60%, #030c21e0); }
.ai-hero-main { position: relative; z-index: 2; width: min(920px, calc(100% - 48px)); padding: 100px 0 70px; margin: auto; text-align: center; }
.ai-hero-pill, .ai-mini-label { display: inline-flex; align-items: center; justify-content: center; gap: 10px; padding: 8px 14px; border: 1px solid #ffffff26; border-radius: var(--card-radius); background: #ffffff0d; color: #d5edff; font-size: 10px; letter-spacing: .16em; }
.ai-hero-pill { margin-bottom: 26px; }
.ai-hero-main h1 { margin: 0 0 14px; font-size: clamp(32px, 4vw, 52px); line-height: 1.3; font-weight: 650; letter-spacing: .03em; text-shadow: 0 6px 30px #0004; }
.ai-hero-eng { margin: 0 0 26px; font-size: 15px; letter-spacing: .08em; color: #d4e5f4; }
.ai-hero-desc { max-width: 820px; margin: 0 auto; color: #e0eaf4; font-size: 15px; line-height: 2; }
.ai-slogan-inner { position: relative; z-index: 2; width: min(1100px, calc(100% - 48px)); text-align: center; }
.ai-base-block { display: flex; flex-direction: column; align-items: center; padding: 90px 0; }
.ai-base-block .ai-mini-label { margin-bottom: 20px; font-size: 10px; }
.ai-base-block h2, .ai-heading, .ai-yijia-top h2 { margin: 0; font-size: var(--section-title); font-weight: 650; line-height: 1.35; letter-spacing: .01em; }
.ai-base-block h2 { color: #fff; }
.ai-base-block p { margin: 12px 0 34px; color: #bfddf2; font-size: 14px; letter-spacing: .14em; }
.ai-base-words { display: flex; justify-content: center; flex-wrap: wrap; column-gap: clamp(28px, 4.2vw, 64px); row-gap: 16px; color: #fff; font-size: clamp(24px, 2.4vw, 32px); font-weight: 600; letter-spacing: .2em; }
.ai-base-words span { white-space: nowrap; }
.ai-scroll { position: absolute; left: 50%; bottom: 32px; width: 24px; height: 42px; border: 1px solid #ffffff66; border-radius: 20px; transform: translateX(-50%); }
.ai-scroll::before { content: ""; position: absolute; left: 50%; top: 8px; width: 3px; height: 8px; border-radius: 2px; background: #fff; animation: wheel 1.8s infinite; }
@keyframes wheel { from { opacity: 0; transform: translate(-50%,0); } 30% { opacity: 1; } to { opacity: 0; transform: translate(-50%,16px); } }
.ai-center-heading { text-align: center; max-width: 960px; margin: 0 auto 40px; }
.ai-kicker { color: #397eaf; font-size: 11px; letter-spacing: .16em; font-weight: 600; margin-bottom: 12px; }
.ai-heading, .ai-yijia-top h2 { color: var(--text); }
.ai-sub, .ai-yijia-en { margin-top: 12px; color: #648199; font-size: 13px; letter-spacing: .1em; }
.ai-lead { max-width: 800px; margin: 22px auto 0; color: var(--muted); font-size: 15px; line-height: 1.9; }

/* Industry: a single image-card row and one full-width detail stage. */
.ai-sectors { padding: 100px 0 108px; background: #fff; }
.ai-sector-switcher { display: flex; flex-direction: column; gap: 8px; }
.ai-sector-tabs { display: grid; grid-template-columns: repeat(9, minmax(0, 1fr)); gap: 8px; }
.ai-sector-trigger { position: relative; display: flex; flex-direction: column; justify-content: flex-end; isolation: isolate; min-width: 0; min-height: 228px; padding: 20px 15px 22px; border: 0; border-radius: var(--card-radius); overflow: hidden; background: #102d4f; text-align: left; color: #fff; cursor: pointer; box-shadow: 0 2px 6px #15324b06; }
.ai-sector-trigger::before { content: ""; position: absolute; inset: 0; z-index: 1; pointer-events: none; background: linear-gradient(180deg, #03132955 0%, #03132980 46%, #031329ed 100%); }
.ai-sector-trigger::after { content: ""; position: absolute; inset: 0; z-index: 1; pointer-events: none; background: linear-gradient(150deg, #084c9e9c, #063878d6); opacity: 0; transition: opacity .3s ease; }
 .ai-sector-card-image { position: absolute; inset: 0; z-index: 0; width: 100%; height: 100%; max-width: none; object-fit: cover; object-position: center; transition: transform .45s ease; }
.ai-sector-trigger:hover .ai-sector-card-image { transform: scale(1.04); }
.ai-sector-trigger > strong, .ai-sector-trigger > em, .ai-sector-trigger > .ai-sector-summary { position: relative; z-index: 2; }

.ai-sector-trigger.active::after { opacity: 1; }
.ai-sector-no { position: absolute; z-index: 2; top: 17px; left: 15px; color: #ffffffa8; font-size: 10px; letter-spacing: .12em; }
.ai-sector-trigger strong { display: block; font-size: 19px; line-height: 1.4; font-weight: 600; white-space: nowrap; }
.ai-sector-trigger em { display: block; margin-top: 7px; font-size: 10px; line-height: 1.5; font-style: normal; color: #ffffffb3; min-height: 30px; }
.ai-sector-summary { display: none; margin-top: 15px; max-width: 112px; font-size: 13px; line-height: 1.8; font-weight: 400; color: #edf6ff; }
.ai-sector-trigger.active { justify-content: flex-start; padding-top: 48px; }
.ai-sector-trigger.active .ai-sector-summary { display: block; }
.ai-sector-stage { position: relative; isolation: isolate; min-height: 420px; border-radius: var(--card-radius); background: #071b36; overflow: hidden; }
.ai-sector-visual { position: absolute; inset: 0; z-index: -2; }
.ai-sector-visual img { width: 100%; height: 100%; object-fit: cover; object-position: center 48%; }
.ai-sector-stage::before { content: ""; position: absolute; inset: 0; z-index: -1; background: linear-gradient(90deg, #04112ff5 0%, #051833ed 28%, #071e3bc7 46%, #071e3b3d 72%, #071e3b08); }
.ai-sector-copy { width: 53%; }
.ai-sector-copy-inner { padding: 44px 48px; color: #fff; }
.ai-sector-stage-no { margin-bottom: 12px; font-size: 12px; letter-spacing: .16em; color: #91b9d5; }
.ai-sector-stage-kicker { margin-bottom: 9px; color: #95bcd8; font-size: 10px; letter-spacing: .18em; }
.ai-sector-copy h3 { margin: 0 0 9px; font-size: 28px; font-weight: 600; line-height: 1.3; }
.ai-sector-stage-en { margin-bottom: 24px; font-size: 12px; letter-spacing: .08em; color: #a9c8df; }
.ai-sector-copy p { margin: 0; font-size: 14px; line-height: 1.95; color: #e1eaf4; }

/* Yijia: uninterrupted pale blue across both sections. */
.ai-yijia-intro, .ai-yijia-platform { background: var(--yijia-bg); position: relative; }
.ai-yijia-intro { padding: 96px 0 0; }
.ai-yijia-heading-compact { margin-bottom: 8px; }
.ai-yijia-intro-inner { position: relative; }
.ai-bubble-track { position: relative; display: flex; justify-content: space-between; align-items: center; max-width: 940px; height: 230px; margin: 0 auto; }
.ai-track-line { position: absolute; left: 5%; right: 5%; top: 48%; height: 76px; border: 1px dashed #86b8dd88; border-radius: 50%; transform: translateY(-50%); }
.ai-bubble { position: relative; width: 112px; height: 112px; aspect-ratio: 1; flex-shrink: 0; display: flex; align-items: center; justify-content: center; padding: 0; border-radius: 50%; background: radial-gradient(circle at 32% 22%, #fff, #f5fbff 58%, #dbeefa); border: 1px solid #bcd6ea; color: #234f73; font-size: 16px; font-weight: 550; box-shadow: inset 0 0 20px #fff9, 0 8px 20px #3d7cbf0d; }
.ai-bubble::before { content: ""; position: absolute; inset: 7px; border: 1px solid #a3d1ed55; border-radius: 50%; }
.ai-bubble:nth-of-type(2n+1) { top: -14px; }
.ai-bubble:nth-of-type(2n) { top: 14px; }

/* Each circular capability floats on its own phase and duration. */
.ai-bubble { --float-x: 4px; --float-y: -14px; animation: ai-bubble-float 6.8s ease-in-out infinite; will-change: transform; }
.ai-bubble.b1 { animation-duration: 6.8s; animation-delay: -1.2s; }
.ai-bubble.b2 { --float-x: -5px; --float-y: 12px; animation-duration: 7.6s; animation-delay: -3.8s; }
.ai-bubble.b3 { --float-x: 3px; --float-y: -16px; animation-duration: 6.4s; animation-delay: -2.5s; }
.ai-bubble.b4 { --float-x: -4px; --float-y: 14px; animation-duration: 8s; animation-delay: -5s; }
.ai-bubble.b5 { --float-x: 4px; --float-y: -12px; animation-duration: 7.2s; animation-delay: -.6s; }
@keyframes ai-bubble-float {
  0%, 100% { transform: translate3d(0, 0, 0); }
  50% { transform: translate3d(var(--float-x), var(--float-y), 0); }
}

.ai-yijia-columns { display: grid; grid-template-columns: 1.16fr .92fr 1fr; gap: 18px; margin: 0; }
.ai-yijia-col { min-width: 0; background: #ffffff8f; padding: 28px; border: 1px solid #dce9f3; border-radius: var(--card-radius); }
.ai-yijia-col h3 { margin: 0 0 18px; color: #20476c; font-size: 20px; font-weight: 600; }
.ai-yijia-col ul { margin: 0; padding-left: 17px; color: #596f83; font-size: 14px; line-height: 1.95; }
.ai-yijia-col li { padding-left: 2px; margin-bottom: 8px; }
.ai-yijia-col li:last-child { margin-bottom: 0; }
.ai-yijia-col li::marker { color: #8daac2; font-size: 11px; }
.ai-yijia-col strong { font-weight: 550; color: #385c7b; }
.ai-yijia-platform { padding: 88px 0 104px; }
.ai-yijia-top { position: relative; text-align: center; margin: 0 auto 40px; }
 .ai-yijia-matrix { display: grid; grid-template-columns: minmax(0, .85fr) minmax(0, 1.5fr); gap: 44px; align-items: center; }
.ai-yijia-device-col--standalone { background: transparent; }
.ai-yijia-showcase { min-width: 0; border-radius: var(--card-radius); overflow: hidden; box-shadow: 0 5px 18px #12345208; }
.ai-yijia-feature-stage { position: relative; isolation: isolate; display: block; min-height: 352px; overflow: hidden; background: radial-gradient(ellipse at 80% 55%, #176ba058, transparent 56%), linear-gradient(115deg, #081a36, #123f69); }
.ai-yijia-feature-stage::before { content: ""; position: absolute; z-index: -1; inset: 0; background-image: linear-gradient(#a5dcff06 1px, transparent 1px), linear-gradient(90deg, #a5dcff06 1px, transparent 1px); background-size: 54px 54px; mask-image: linear-gradient(90deg, transparent, #000); }
.ai-yijia-feature-stage::after { content: ""; position: absolute; z-index: -1; width: 720px; height: 720px; right: -90px; top: -140px; border: 1px solid #a4d6ff14; border-radius: 50%; box-shadow: 0 0 0 65px #a4d6ff06, 0 0 0 130px #a4d6ff04; }
.ai-yijia-feature-display { padding: 38px 40px; min-width: 0; color: #fff; }
.ai-feature-eyebrow { display: flex; align-items: center; gap: 18px; margin-bottom: 36px; color: #b5d5ef; font-size: 12px; }
.ai-feature-eyebrow span:first-child { padding: 6px 10px; border: 1px solid #bfdcff38; border-radius: 4px; }
#ai-feature-index { color: #8cafca; font-size: 11px; letter-spacing: .1em; }
.ai-yijia-feature-display h3 { margin: 12px 0 20px; font-size: 28px; font-weight: 600; line-height: 1.35; }
.ai-yijia-feature-display p { margin: 0; max-width: 540px; min-height: 90px; font-size: 15px; line-height: 1.95; color: #d5e4f1; }
.ai-feature-rule { width: 42px; height: 2px; margin-top: 26px; background: #74b7ed; }
.ai-yijia-device-col { position: relative; min-width: 0; }
.ai-phone-stage { position: relative; min-height: 468px; width: min(400px, 100%); margin: auto; }
.ai-phone-glow { position: absolute; inset: 20px -20px; background: radial-gradient(ellipse, #4bcbff24, transparent 65%); }
.ai-phone-shell { position: absolute; width: 172px; padding: 7px; border-radius: 26px; background: linear-gradient(140deg, #53667b, #0d1625 45%, #283e56); box-shadow: 0 18px 38px #0005, inset 0 0 0 1px #ffffff52; }
.ai-phone-shell img { width: 100%; height: auto; border-radius: 20px; background: #fff; }
.ai-phone-notch { position: absolute; z-index: 1; width: 58px; height: 13px; top: 7px; left: 50%; transform: translateX(-50%); border-radius: 0 0 9px 9px; background: #111d2c; }
.ai-phone-shell::after { content: ""; position: absolute; bottom: 10px; left: 50%; transform: translateX(-50%); width: 56px; height: 3px; border-radius: 3px; background: #ffffff52; }
.phone-left { left: 10px; top: 31px; transform: rotate(-6deg); animation: phone-left 7s ease-in-out infinite; }
.phone-right { right: 10px; top: 79px; transform: rotate(5deg); animation: phone-right 7.8s ease-in-out infinite; }
@keyframes phone-left { 50% { transform: translateY(-7px) rotate(-5deg); } }
@keyframes phone-right { 50% { transform: translateY(7px) rotate(4deg); } }
.ai-yijia-feature-tabs { display: grid; grid-template-columns: repeat(7, minmax(0, 1fr)); background: #f6f9fc; }
.ai-feature-tab { position: relative; min-height: 72px; min-width: 0; border: 0; border-top: 3px solid transparent; border-right: 1px solid #dce7ef; border-radius: 0; padding: 12px 8px 15px; color: #7b8b9a; background: #f4f7fa; font-size: 14px; font-weight: 550; cursor: pointer; transition: color .25s, background .25s, border-color .25s; }
.ai-feature-tab:last-child { border-right: 0; }
.ai-feature-tab.active { background: #fff; color: #173c62; border-top-color: var(--blue); }
.ai-feature-tab:hover { background: #fff; color: #1668bb; }
.ai-feature-tab:focus-visible, .ai-sector-trigger:focus-visible { outline-offset: -4px; outline-color: #68c2ff; }

/* Footer and progressive enhancement */
.ai-footer { padding: 48px 0 22px; background: #071626; color: #fff; }
.ai-footer-inner { display: grid; grid-template-columns: 1.2fr 1fr 1fr 1fr; gap: 30px; }
.ai-footer-logo { width: 184px; }
.ai-footer-slogan { color: #ffffffad; font-size: 13px; line-height: 1.9; margin: 18px 0 0; }
.ai-footer-col h3 { margin: 0 0 14px; font-size: 15px; font-weight: 600; }
.ai-footer-col a { display: block; padding: 6px 0; color: #ffffffad; font-size: 13px; }
.ai-footer-col a:hover { color: #fff; }
.ai-footer-bottom { display: flex; justify-content: space-between; gap: 20px; padding-top: 20px; margin-top: 28px; border-top: 1px solid #ffffff12; font-size: 11px; color: #ffffff80; }
.ai-reveal { opacity: 1; }
.ai-motion-ready .ai-reveal { opacity: 0; transform: translateY(16px); transition: opacity .6s ease, transform .6s ease; }
.ai-motion-ready .ai-reveal.visible { opacity: 1; transform: none; }

@media (max-width: 1320px) {
  .ai-side-progress { display: none; }
  .ai-header-links { gap: 18px; font-size: 13px; }
  .ai-back-link { display: none; }
}
@media (max-width: 1100px) {
  .ai-sector-trigger { padding-inline: 11px; min-height: 210px; }
  .ai-sector-trigger strong { font-size: 17px; }
  .ai-sector-summary { font-size: 12px; }
  .ai-sector-no { left: 11px; }
  .ai-sector-copy { width: 60%; }
  .ai-sector-copy-inner { padding: 36px; }
  .ai-yijia-columns { gap: 12px; }
  .ai-yijia-col { padding: 24px 20px; }
  .ai-yijia-matrix { gap: 28px; }
  .ai-yijia-feature-display { padding-inline: 30px; }
  .ai-phone-shell { width: 156px; }
  .phone-left { left: 15px; top: 46px; }
  .phone-right { right: 22px; top: 85px; }
}
@media (max-width: 980px) {
  .ai-header-links { display: none; }
  .ai-menu-btn { display: block; }
  .ai-sector-tabs { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .ai-sector-trigger { min-height: 188px; padding: 18px; }
  .ai-sector-no { left: 18px; }
  .ai-sector-trigger strong { font-size: 20px; }
  .ai-sector-trigger em { min-height: 15px; }
  .ai-sector-summary { max-width: 140px; font-size: 12px; margin-top: 8px; }
  .ai-sector-trigger.active { padding-top: 42px; }
  .ai-yijia-columns { grid-template-columns: 1fr; gap: 14px; }
  .ai-yijia-col { padding: 26px 30px; }
  .ai-sector-copy { width: 68%; }
  .ai-yijia-matrix { grid-template-columns: minmax(0, .8fr) minmax(0, 1.2fr); gap: 22px; }
  .ai-yijia-feature-tabs { display: flex; flex-wrap: wrap; }
  .ai-feature-tab { flex: 1 0 25%; border-bottom: 1px solid #dce7ef; }
  .ai-feature-tab:nth-child(4) { border-right: 0; }
  .ai-feature-tab:nth-child(n+5) { flex-basis: 33.333%; border-bottom: 0; }
  .ai-phone-shell { width: 144px; }
  .phone-left { left: 2px; top: 56px; }
  .phone-right { right: 6px; top: 104px; }
  .ai-feature-tab { font-size: 14px; min-height: 68px; }
  .ai-bubble { width: 96px; height: 96px; font-size: 14px; }
  .ai-footer-inner { grid-template-columns: 1fr 1fr; row-gap: 32px; }
}
@media (max-width: 720px) {
  :root { --body-size: 14px; }
  html { scroll-padding-top: 88px; }
  .ai-width { width: calc(100% - 32px); }
  .ai-header { height: 72px; padding: 0 18px; }
  .ai-header-brand img { width: 154px; }
  .ai-hero-main { width: calc(100% - 40px); padding: 110px 0 100px; }
  .ai-hero-pill { font-size: 8px; letter-spacing: .08em; padding: 8px 10px; margin-bottom: 22px; }
  .ai-hero-main h1 { font-size: clamp(29px, 7vw, 36px); }
  .ai-hero-eng { font-size: 12px; line-height: 1.8; letter-spacing: .03em; }
  .ai-hero-desc { font-size: 14px; line-height: 1.9; }
  .ai-base-block p { font-size: 12px; margin-bottom: 28px; }
  .ai-base-block .ai-mini-label { font-size: 9px; }
  .ai-base-words { column-gap: 28px; row-gap: 22px; font-size: 21px; letter-spacing: .16em; max-width: 320px; }
  .ai-center-heading { margin-bottom: 30px; }
  .ai-kicker { font-size: 10px; }
  .ai-sub, .ai-yijia-en { font-size: 11px; line-height: 1.7; letter-spacing: .06em; }
  .ai-lead { margin-top: 18px; font-size: 14px; }
  .ai-sectors { padding: 68px 0; }
  .ai-sector-tabs { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; }
  .ai-sector-trigger { min-height: 176px; padding: 16px; }
  .ai-sector-no { top: 14px; left: 16px; }
  .ai-sector-trigger strong { font-size: 19px; }
  .ai-sector-trigger.active { padding-top: 40px; }
  .ai-sector-trigger em { font-size: 10px; }
  .ai-sector-summary { font-size: 12px; line-height: 1.6; max-width: none; }
  .ai-sector-stage { min-height: 520px; padding-top: 205px; }
  .ai-sector-visual { bottom: auto; height: 260px; }
  .ai-sector-visual img { object-position: center; }
  .ai-sector-stage::before { background: linear-gradient(180deg, transparent 0, #071b3622 140px, #071b36 255px); }
  .ai-sector-copy { width: 100%; }
  .ai-sector-copy-inner { padding: 28px 24px 32px; }
  .ai-sector-stage-no { margin-bottom: 10px; }
  .ai-sector-copy h3, .ai-yijia-feature-display h3 { font-size: 23px; }
  .ai-sector-copy p { font-size: 14px; line-height: 1.9; }
  .ai-sector-stage-en { margin-bottom: 20px; font-size: 11px; }
  .ai-yijia-intro { padding: 68px 0 0; }
  .ai-yijia-heading-compact { margin-bottom: 0; }
  .ai-bubble-track { height: 156px; }
  .ai-bubble { width: clamp(54px, 16vw, 82px); height: auto; aspect-ratio: 1; font-size: clamp(10px, 2.8vw, 13px); }
  .ai-bubble::before { inset: 4px; }
  .ai-bubble:nth-of-type(2n+1) { top: -8px; }
  .ai-bubble:nth-of-type(2n) { top: 8px; }
  .ai-track-line { height: 46px; }
  .ai-yijia-col { padding: 24px; }
  .ai-yijia-col h3 { font-size: 19px; }
  .ai-yijia-platform { padding: 64px 0 72px; }
  .ai-yijia-top { margin-bottom: 30px; }
  .ai-yijia-matrix { grid-template-columns: 1fr; gap: 24px; }
  .ai-yijia-feature-stage { min-height: 330px; }
  .ai-bubble { --float-x: 2px; --float-y: -9px; }
  .ai-bubble.b2, .ai-bubble.b4 { --float-x: -2px; --float-y: 9px; }
  .ai-bubble.b3, .ai-bubble.b5 { --float-x: 2px; --float-y: -9px; }
  .ai-yijia-feature-display { padding: 30px 26px; }
  .ai-feature-eyebrow { margin-bottom: 24px; }
  .ai-yijia-feature-display h3 { margin-bottom: 14px; }
  .ai-yijia-feature-display p { min-height: 80px; font-size: 14px; }
  .ai-feature-rule { margin-top: 18px; }
  .ai-phone-stage { min-height: 380px; width: min(340px, 100%); }
  .ai-phone-shell { width: 140px; padding: 6px; border-radius: 24px; }
  .ai-phone-shell img { border-radius: 18px; }
  .phone-left { left: 30px; top: 26px; }
  .phone-right { right: 28px; top: 54px; }
  .ai-yijia-feature-tabs { display: flex; flex-wrap: wrap; }
  .ai-feature-tab { flex: 1 0 25%; min-height: 60px; font-size: 13px; border-bottom: 1px solid #dce7ef; }
  .ai-feature-tab:nth-child(4) { border-right: 0; }
  .ai-feature-tab:nth-child(n+5) { flex-basis: 33.333%; border-bottom: 0; }
  .ai-footer-inner { grid-template-columns: 1fr; gap: 28px; }
  .ai-footer-bottom { flex-direction: column; gap: 10px; line-height: 1.8; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .ai-motion-ready .ai-reveal { opacity: 1; transform: none; }
}

/* V27: image cards navigate to their own case pages. */
.ai-sector-trigger { padding-bottom: 28px; }
.ai-sector-case-hint { position: absolute; z-index: 2; left: 15px; bottom: 12px; display: flex; align-items: center; gap: 7px; color: #d1e6fc; font-size: 10px; opacity: 0; transition: opacity .25s ease; }
.ai-sector-trigger.active .ai-sector-case-hint, .ai-sector-trigger:focus-visible .ai-sector-case-hint, .ai-sector-trigger:hover .ai-sector-case-hint { opacity: 1; }
@media (max-width: 1100px) { .ai-sector-case-hint { left: 11px; } }
@media (max-width: 980px) { .ai-sector-case-hint { left: 18px; } }
@media (max-width: 720px) {
  .ai-sector-case-hint { left: 16px; opacity: 1; bottom: 10px; }
  .ai-sector-trigger { padding-bottom: 32px; }
}