/* 知跃 KnowLeap 宣传页 v2 · 美术方向 A「深夜书桌」
   两色纪律：近黑墨绿 + 品牌绿；其余只用中性灰。动效只作用于 transform / opacity。 */

:root {
  --bg: #0f120d;
  --bg-2: #14180f;
  --surface: #171b13;
  --surface-2: #1d2318;
  --line: rgba(255, 255, 255, 0.08);
  --line-strong: rgba(255, 255, 255, 0.16);
  --text: #f2f4ee;
  --muted: #9aa192;
  --muted-2: #767d6c;
  --green: #bedb8a;
  --green-2: #8fae5e;
  --green-deep: #46582c;
  --warn: #c97a57;
  --r-lg: 20px;
  --r: 14px;
  --r-sm: 10px;
  --shadow: 0 30px 80px rgba(0, 0, 0, 0.55);
  --font: 'Segoe UI', 'Microsoft YaHei UI', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
  --mono: 'Cascadia Mono', 'Consolas', 'Courier New', monospace;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

* { box-sizing: border-box; }
/* 注意：不要在这里写 overflow-x（无论是 hidden 还是 clip）。
   按规范，html 的 overflow 不是 visible 时，body 的 overflow 就不再向视口传播，
   body 会自己变成滚动容器 —— window.scrollY 不再跟随滚动，桌面的 Lenis / ScrollTrigger
   直接失效（表现：分幕不再钉住切换，变成普通往下滚；2026-10-05 踩过）。
   横向溢出交给 body 的 overflow-x（沿用原来的写法）+ 移动端关掉光晕来解决。 */
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3 { margin: 0; font-weight: 800; letter-spacing: -0.01em; line-height: 1.18; }
p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: var(--green); text-decoration: none; }
/* height:auto 必须写：截图都带 width/height 属性（防抖动），只设宽度会把图拉变形 */
img { max-width: 100%; display: block; height: auto; }
button { font: inherit; color: inherit; cursor: pointer; }
:focus-visible { outline: 2px solid var(--green-2); outline-offset: 3px; border-radius: 6px; }

.container { width: min(1320px, 100% - 112px); margin-inline: auto; }
.container.narrow { width: min(880px, 100% - 112px); }

.ic { width: 18px; height: 18px; flex: none; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }

/* 颗粒噪点：固定层，几乎不可见，但让深色不再"塑料" */
.grain {
  position: fixed; inset: 0; z-index: 9; pointer-events: none; opacity: 0.05; mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ---------- 顶部进度条 ---------- */
.progress { position: fixed; inset: 0 0 auto; height: 2px; z-index: 60; pointer-events: none; }
.progress span { display: block; height: 100%; width: 0; background: linear-gradient(90deg, var(--green-2), var(--green)); }

/* ---------- Act 0 开场 ---------- */
.preloader {
  position: fixed; inset: 0; z-index: 80; background: var(--bg);
  display: grid; place-items: center; transition: opacity 0.6s var(--ease), visibility 0.6s;
}
.preloader.is-done { opacity: 0; visibility: hidden; }
.pre-inner { display: flex; flex-direction: column; align-items: center; gap: 18px; }
.pre-name { font-size: 15px; letter-spacing: 0.42em; color: var(--muted); text-transform: uppercase; }
.pre-line { display: block; width: 220px; height: 1px; background: var(--line-strong); overflow: hidden; }
.pre-line i { display: block; height: 100%; width: 0; background: var(--green); animation: preLine 1.1s var(--ease) forwards; }
@keyframes preLine { to { width: 100%; } }
.pre-count { font-family: var(--mono); font-size: 12px; color: var(--muted-2); }
body.no-pre .preloader { display: none; }

/* ---------- 导航 ---------- */
.nav {
  position: fixed; inset: 0 0 auto; z-index: 50; padding: 14px 0;
  transition: background 0.3s, border-color 0.3s, padding 0.3s;
  border-bottom: 1px solid transparent;
}
.nav.is-stuck { padding: 8px 0; background: rgba(15, 18, 13, 0.78); backdrop-filter: blur(16px) saturate(140%); border-bottom-color: var(--line); }
.nav-inner { display: flex; align-items: center; gap: 22px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); font-weight: 800; }
.brand-mark {
  display: grid; place-items: center; width: 30px; height: 30px; border-radius: 9px;
  background: var(--green); color: #10140c; font-size: 16px; line-height: 1; font-weight: 900;
}
.brand-text { font-size: 16px; letter-spacing: 0.02em; }
.brand-text em { font-style: normal; color: var(--green); font-weight: 600; letter-spacing: 0.06em; }
.nav-links { display: flex; gap: 28px; margin-left: 20px; }
.nav-links a { color: var(--muted); font-size: 14px; transition: color 0.2s; }
.nav-links a:hover { color: var(--green); }
.nav .btn { margin-left: auto; }
.nav-toggle { display: none; background: none; border: 0; padding: 8px; }
.nav-toggle span { display: block; width: 20px; height: 2px; background: var(--text); margin: 5px 0; transition: transform 0.25s; }
.nav-toggle[aria-expanded="true"] span:first-child { transform: translateY(3.5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:last-child { transform: translateY(-3.5px) rotate(-45deg); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 9px;
  border: 1px solid transparent; border-radius: 999px; padding: 13px 26px;
  font-size: 15px; font-weight: 700; white-space: nowrap; transition: transform 0.2s var(--ease), background 0.2s, border-color 0.2s, box-shadow 0.2s;
}
.btn-primary { background: var(--green); color: #10140c; }
.btn-primary:hover { background: #cfe9a5; transform: translateY(-2px); box-shadow: 0 12px 30px rgba(190, 219, 138, 0.22); }
.btn-ghost { background: transparent; border-color: var(--line-strong); color: var(--text); }
.btn-ghost:hover { border-color: var(--green); color: var(--green); transform: translateY(-2px); }
.btn-sm { padding: 9px 18px; font-size: 13.5px; }

/* 手机端下载入口：默认隐藏，浏览器判定为手机（html.is-mobile）时才显示；
   同时把只在桌面上有意义的文案与按钮收起来。用 :not() 而不是覆盖 display，
   以免把按钮的 inline-flex 布局改掉。 */
html:not(.is-mobile) [data-android] { display: none !important; }
html:not(.is-mac) [data-mac-only] { display: none !important; }
/* iPad：UA 与 macOS 相同但装不了 Android 包，单独提示，并把 Android 入口收起来 */
html:not(.is-ipad) [data-ipad-only] { display: none !important; }
html.is-ipad [data-android], html.is-ipad [data-win-only] { display: none !important; }
html.is-mobile [data-win-only] { display: none !important; }
/* 在 Mac 上把 Windows 入口收起来（首屏/收尾都会切到 macOS 版） */
html.is-mac [data-win-only] { display: none !important; }
.mac-alt a { color: var(--green-2); }
.mac-alt a.is-recommended { color: var(--green); font-weight: 700; }
.mac-alt a.is-recommended::after { content: '（推荐）'; font-size: 11px; }
html.is-mobile .formula-break { display: inline; }
.btn-lg { padding: 15px 30px; font-size: 16px; }
.btn-xl { padding: 18px 40px; font-size: 18px; }

/* ---------- 通用文字 ---------- */
.eyebrow {
  display: inline-flex; align-items: center; gap: 9px; margin-bottom: 18px;
  font-size: 12.5px; font-weight: 700; letter-spacing: 0.2em; color: var(--green-2);
}
.eyebrow .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--green); animation: pulse 2.4s infinite; }
@keyframes pulse { 0% { box-shadow: 0 0 0 0 rgba(190, 219, 138, 0.5); } 70% { box-shadow: 0 0 0 11px rgba(190, 219, 138, 0); } 100% { box-shadow: 0 0 0 0 rgba(190, 219, 138, 0); } }
.display { font-size: clamp(34px, 4.4vw, 68px); letter-spacing: -0.03em; line-height: 1.1; }
.display-2 { font-size: clamp(28px, 3.4vw, 48px); letter-spacing: -0.02em; }
.sub { margin-top: 16px; color: var(--muted); font-size: 17px; max-width: 40em; }
.head { max-width: 720px; margin-bottom: 56px; }
.head-tight { margin-bottom: 28px; }

/* 遮罩上滑（标题逐行） */
.line { display: block; overflow: hidden; }
.line > span { display: block; white-space: nowrap; transform: translateY(112%); transition: transform 1s var(--ease); }
[data-lines].is-in .line > span { transform: none; }
[data-lines] .line:nth-child(2) > span { transition-delay: 0.09s; }

/* 进入视口淡入（只做一次） */
[data-fade] { opacity: 0; transform: translateY(26px); transition: opacity 0.85s var(--ease), transform 0.85s var(--ease); }
[data-fade].is-in { opacity: 1; transform: none; }

/* ---------- 分幕：sticky 舞台 ---------- */
.act { position: relative; }
.stage {
  position: sticky; top: 0; min-height: 100vh; display: flex; flex-direction: column;
  justify-content: center; overflow: hidden;
}
.act-hero { height: 320vh; }
.act-detail { height: 760vh; }
.act-start { height: 200vh; }
.act-finale { height: 150vh; }
.stage-note { margin-top: 34px; font-size: 12px; color: var(--muted-2); }
.glow {
  position: absolute; z-index: 0; pointer-events: none; border-radius: 50%;
  width: 900px; height: 900px; filter: blur(140px); opacity: 0.5;
  background: radial-gradient(circle, rgba(190, 219, 138, 0.34), rgba(190, 219, 138, 0) 68%);
}
.act-hero .glow { top: -34%; right: -14%; animation: drift 22s ease-in-out infinite alternate; }
@keyframes drift { from { transform: translate3d(0, 0, 0) scale(1); } to { transform: translate3d(-70px, 60px, 0) scale(1.14); } }
.scroll-hint {
  position: absolute; left: 50%; bottom: 30px; transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center; gap: 8px;
  font-size: 11.5px; letter-spacing: 0.22em; color: var(--muted-2);
}
.scroll-hint span { width: 1px; height: 34px; background: linear-gradient(180deg, var(--green), transparent); animation: hint 2.2s infinite; }
@keyframes hint { 0%, 100% { opacity: 0.25; transform: scaleY(0.6); } 50% { opacity: 1; transform: scaleY(1); } }

/* ---------- Act 1 首屏 ---------- */
/* 首屏/功能两幕在桌面端用更宽的容器（100% - 96px）装更大的画面。
   注意必须限定在桌面：手机上这个 96px 会把正文容器压到 224–294px，
   标题与正文于是排到容器外、右侧被切（真机"画面没对齐"就是这么来的）。 */
@media (min-width: 901px) {
  .act-hero .container { width: min(1460px, 100% - 96px); }
}
.hero-grid { position: relative; z-index: 2; display: grid; grid-template-columns: 0.88fr 1.12fr; gap: 56px; align-items: center; }
.hero-copy .lead { margin-top: 26px; font-size: 18px; color: #c9cec1; max-width: 30em; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 34px; }
.hero-meta { margin-top: 20px; font-size: 13px; color: var(--muted-2); }

/* 3D 设备 */
.device { perspective: 1700px; }
.device-inner {
  position: relative; border-radius: var(--r-lg); overflow: hidden;
  background: var(--surface); border: 1px solid var(--line-strong);
  box-shadow: var(--shadow), 0 0 0 1px rgba(190, 219, 138, 0.06);
  transform: rotateY(-13deg) rotateX(5deg) translateZ(0);
  transition: transform 0.5s var(--ease);
  will-change: transform;
}
.device-bar { display: flex; align-items: center; gap: 10px; padding: 11px 14px; background: var(--surface-2); border-bottom: 1px solid var(--line); }
.dots { display: flex; gap: 6px; }
.dots i { width: 9px; height: 9px; border-radius: 50%; background: #333a2c; }
.dots i:first-child { background: #5a4636; }
.dots i:nth-child(2) { background: #57543a; }
.dots i:last-child { background: #465a34; }
.device-title { font-size: 12px; color: var(--muted); font-weight: 600; }
.device-tag { margin-left: auto; font-family: var(--mono); font-size: 10.5px; color: var(--green-2); border: 1px solid var(--line-strong); border-radius: 999px; padding: 2px 9px; }
.device-screen { position: relative; aspect-ratio: 16 / 10; background: #0b0e09; }
.device-screen .shot {
  position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; object-position: left top;
  opacity: 0; transform: scale(1.03); transition: opacity 0.7s var(--ease), transform 1.1s var(--ease);
}
.device-screen .shot.is-active { opacity: 1; transform: scale(1); }

.beats { margin-top: 22px; display: flex; flex-direction: column; gap: 10px; }
.beat {
  display: flex; align-items: center; gap: 12px; font-size: 14px; color: var(--muted-2);
  transition: color 0.4s, transform 0.4s var(--ease);
}
.beat b { font-family: var(--mono); font-size: 11.5px; color: var(--muted-2); transition: color 0.4s; }
.beat.is-active { color: var(--text); transform: translateX(6px); }
.beat.is-active b { color: var(--green); }

/* ---------- Act 2 痛点 ---------- */
.act-pain { padding: 150px 0 130px; border-block: 1px solid var(--line); background: var(--bg-2); }
.pain-wrap { max-width: 1000px; }
.pain-list { display: flex; flex-direction: column; gap: 4px; margin: 8px 0 46px; }
.pain-item {
  font-size: clamp(24px, 3vw, 42px); font-weight: 700; letter-spacing: -0.02em; line-height: 1.4;
  color: var(--muted-2); transition: color 0.5s var(--ease), opacity 0.5s var(--ease), transform 0.5s var(--ease);
  opacity: 0.34; transform: translateX(-14px);
}
.pain-item.is-in { opacity: 1; transform: none; }
.pain-item.is-past { opacity: 0.3; }
.pain-item.is-near { color: var(--text); }
.pain-turn { font-size: clamp(19px, 2vw, 26px); color: var(--muted); }
.pain-turn strong { color: var(--green); font-weight: 700; }

/* ---------- Act 3 Bento（取自候选版 promo-next，按本页变量与断点适配） ---------- */
.act-ability { padding: 150px 0; }
.bento-grid { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 16px; }
.bento-card {
  position: relative; display: block; overflow: hidden;
  background: linear-gradient(130deg, #1c2317, #141910);
  border: 1px solid var(--line); border-radius: 16px; padding: 32px;
  transition: transform 0.3s var(--ease), opacity 0.3s, border-color 0.3s;
}
.bento-card:hover { transform: translateY(-4px); border-color: #bedb8a55; }
.bento-grid:has(.bento-card:hover) .bento-card:not(:hover) { opacity: 0.66; }
.mini-kicker { font-family: var(--mono); font-size: 9px; letter-spacing: 1px; color: var(--green); }
.bento-card h3 { font-size: 23px; font-weight: 700; margin: 18px 0 12px; }
.bento-card p { color: var(--muted); font-size: 13px; line-height: 1.85; }
.bento-arrow { position: absolute; top: 27px; right: 28px; font-size: 22px; color: var(--green); }
.bento-reader { grid-column: span 7; min-height: 330px; }
.bento-reader > div { position: relative; z-index: 2; max-width: 245px; }
.bento-reader h3 { font-size: 30px; }
.bento-reader img {
  position: absolute; width: 550px; max-width: none; top: 100px; left: 47%;
  border: 1px solid var(--line-strong); border-radius: 9px; transform: rotate(-8deg); box-shadow: 0 20px 50px #0008;
}
.bento-audio { grid-column: span 5; }
.waveform { display: flex; align-items: center; justify-content: center; gap: 6px; height: 85px; }
.waveform i { width: 3px; height: 45px; border-radius: 3px; background: var(--green); transform: scaleY(0.35); transform-origin: center; opacity: 0.75; }
.waveform i:nth-child(3n) { transform: scaleY(0.75); }
.waveform i:nth-child(4n) { transform: scaleY(1.2); }
.waveform i:nth-child(5n) { transform: scaleY(0.6); }
.bento-audio .waveform { margin: 22px 0 8px; }
.bento-memory, .bento-practice, .bento-orb { grid-column: span 4; min-height: 320px; }
.memory-tags { display: flex; align-items: flex-start; flex-direction: column; gap: 8px; margin: 26px 0 25px; }
.memory-tags span { border: 1px solid var(--line-strong); background: #bedb8a06; border-radius: 5px; padding: 6px 10px; font-size: 11px; color: var(--muted); }
.memory-tags span:nth-child(2) { margin-left: 25px; color: var(--green); border-color: #bedb8a38; }
.practice-formula { font: italic 26px Georgia, 'Times New Roman', serif; color: #dce8ca; margin: 55px 0; white-space: nowrap; }
.practice-formula > span { color: #7d8b6b; margin-inline: 7px; }
.orb {
  display: block; width: 66px; height: 66px; margin: 32px auto 30px; border-radius: 50%;
  background: radial-gradient(circle at 30% 25%, #d5e6b7, #a2bc79 48%, #526d37);
  box-shadow: inset 0 0 0 1px #ffffff36, 0 0 0 14px #bedb8a04, 0 20px 40px #0007, 0 0 50px #a8c57617;
}
.bento-simple { grid-column: span 12; display: grid; grid-template-columns: 1.2fr 1fr; gap: 14px 70px; align-items: center; padding-block: 38px; }
.bento-simple .mini-kicker { grid-column: 1; }
.bento-simple .simple-word { grid-column: 2; grid-row: 1 / 4; font-size: 85px; font-weight: 750; letter-spacing: 16px; color: #ffffff10; justify-self: center; }
.simple-word > span { color: var(--green); }
.bento-simple h3 { margin: 0; font-size: 28px; }
.bento-simple p { grid-column: 1; }

/* ---------- Act 4 功能深潜 ---------- */
@media (min-width: 901px) {
  .act-detail .container { width: min(1460px, 100% - 96px); }
}
.detail-grid { display: grid; grid-template-columns: 158px minmax(0, 1fr) 312px; grid-template-areas: 'head head head' 'rail screen copy'; gap: 24px 32px; align-items: center; }
.detail-grid .head { grid-area: head; margin-bottom: 0; }
.rail { grid-area: rail; display: flex; flex-direction: column; gap: 2px; }
.rail button {
  position: relative; display: flex; align-items: center; gap: 11px; width: 100%; text-align: left;
  background: none; border: 0; padding: 10px 0; color: var(--muted-2); font-size: 14px; transition: color 0.3s;
}
.rail button b { font-family: var(--mono); font-size: 11px; opacity: 0.7; }
.rail button i { position: absolute; left: 0; bottom: 4px; height: 1px; width: 0; background: var(--green); transition: width 0.45s var(--ease); }
.rail button:hover { color: var(--text); }
.rail button.is-active { color: var(--green); font-weight: 700; }
.rail button.is-active i { width: 100%; }
.detail-stage { grid-area: screen; display: contents; }
.detail-screen {
  grid-area: screen; position: relative; aspect-ratio: 16 / 10; border-radius: var(--r-lg); overflow: hidden;
  border: 1px solid var(--line-strong); background: #0b0e09; box-shadow: var(--shadow);
}
.detail-shot {
  position: absolute; inset: 0; margin: 0; opacity: 0; transform: scale(1.05);
  transition: opacity 0.5s var(--ease), transform 0.9s var(--ease);
}
.detail-shot.is-active { opacity: 1; transform: scale(1); }
/* 截图推近到"看得清"的区域：窗口截图整幅缩到这个尺寸是看不清的 */
.detail-shot img {
  width: 100%; height: 100%; object-fit: cover; object-position: left top;
  transform: scale(var(--z, 1.5)); transform-origin: var(--ox, 50%) var(--oy, 24%);
}
.detail-shot[data-i="0"] { --z: 1.3; --ox: 60%; --oy: 26%; }
.detail-shot[data-i="1"] { --z: 1.7; --ox: 82%; --oy: 14%; }
.detail-shot[data-i="2"] { --z: 1.3; --ox: 50%; --oy: 26%; }
.detail-shot[data-i="3"] { --z: 1.3; --ox: 50%; --oy: 26%; }
.detail-shot[data-i="4"] { --z: 1.35; --ox: 58%; --oy: 40%; }
.detail-shot[data-i="5"] { --z: 1.3; --ox: 54%; --oy: 30%; }
.detail-shot[data-i="7"] { --z: 1.3; --ox: 50%; --oy: 28%; }
.detail-shot.fit-height img { object-fit: contain; object-position: center center; transform: none; background: var(--bg); }
.detail-copy { grid-area: copy; position: relative; min-height: 250px; }
.detail-item {
  position: absolute; inset: 0; opacity: 0; transform: translateY(14px);
  transition: opacity 0.45s var(--ease), transform 0.45s var(--ease); pointer-events: none;
}
.detail-item.is-active { opacity: 1; transform: none; pointer-events: auto; }
.detail-item h3 { font-size: 22px; margin-bottom: 16px; }
.detail-item li { position: relative; padding-left: 22px; margin-bottom: 12px; color: var(--muted); font-size: 14.5px; }
.detail-item li::before {
  content: ''; position: absolute; left: 0; top: 8px; width: 12px; height: 12px; border-radius: 50%;
  background: rgba(190, 219, 138, 0.14) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23bedb8a' stroke-width='3.6' stroke-linecap='round'%3E%3Cpath d='M5 12.5 10 17.5 19 6.5'/%3E%3C/svg%3E") center/8px no-repeat;
}

/* ---------- Act 5 现场演示 ---------- */
/* 现场演示：和首屏/功能一样是滚轮驱动的分幕（滚动推进模式与帧） */
.act-demo { height: 420vh; background: var(--bg-2); border-block: 1px solid var(--line); }
.act-demo .stage { padding: 118px 0 48px; }

/* ---------- 现场演示：三个真实界面 ---------- */
/* 宽度按「整个演示能落在一屏里」来定：帧 + 标签 + 控件 ≈ 940px 高 */
.demo { max-width: 960px; }
.act-demo .head { margin-bottom: 34px; }
.demo-hint { margin-top: 22px; font-size: 12.5px; color: var(--muted-2); }
.demo-hint::before { content: '↓ '; color: var(--green-2); }
.demo-tabs { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 18px; }
.demo-tabs button {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 18px; border-radius: 999px; border: 1px solid var(--line-strong);
  background: transparent; color: var(--muted); font-size: 14px; font-weight: 600;
  transition: color 0.25s, border-color 0.25s, background 0.25s;
}
.demo-tabs button .ic { width: 16px; height: 16px; }
.demo-tabs button:hover { color: var(--text); border-color: var(--green-2); }
.demo-tabs button.is-active { background: var(--green); border-color: var(--green); color: #10140c; }
.demo-panel { display: none; }
.demo-panel.is-active { display: block; animation: fadeUp 0.45s var(--ease); }
@keyframes fadeUp { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }

.demo-frame {
  position: relative; margin: 0; aspect-ratio: 16 / 10; overflow: hidden;
  border: 1px solid var(--line-strong); border-radius: var(--r-lg); background: #0b0e09;
  box-shadow: var(--shadow);
}
.demo-shot { position: absolute; inset: 0; opacity: 0; transition: opacity 0.55s var(--ease); }
.demo-shot.is-active { opacity: 1; }
.demo-shot img {
  width: 100%; height: 100%; object-fit: cover; object-position: left top;
  transform: scale(var(--z, 1)); transform-origin: var(--ox, 50%) var(--oy, 50%);
}
/* 每帧推近到真正要看的位置：面板、确认框、回答 */
[data-panel='summary'] .demo-shot[data-i='0'] img { --z: 1.9; --ox: 92%; --oy: 21%; }
[data-panel='summary'] .demo-shot[data-i='1'] img { --z: 1.12; --ox: 50%; --oy: 44%; }
[data-panel='summary'] .demo-shot[data-i='2'] img { --z: 1.95; --ox: 90%; --oy: 39%; }
[data-panel='ask'] .demo-shot[data-i='0'] img { --z: 1.4; --ox: 44%; --oy: 42%; }
[data-panel='ask'] .demo-shot[data-i='1'] img { --z: 1.9; --ox: 92%; --oy: 27%; }

.demo-controls { display: flex; align-items: center; flex-wrap: wrap; gap: 14px; margin-top: 18px; }
.demo-steps { display: inline-flex; align-items: center; gap: 7px; }
.demo-step {
  width: 9px; height: 9px; padding: 0; border-radius: 50%;
  border: 1px solid var(--line-strong); background: transparent; transition: background 0.25s, border-color 0.25s, transform 0.25s;
}
.demo-step.is-active { background: var(--green); border-color: var(--green); transform: scale(1.15); }
.demo-caption { flex: 1 1 260px; margin: 0; font-size: 13.5px; color: var(--muted); }
.demo-note { margin-top: 10px; font-size: 12px; color: var(--muted-2); }
.demo-disclaimer { margin-top: 26px; font-size: 12px; color: var(--muted-2); }
.live-frame { border: 1px solid var(--line-strong); border-radius: var(--r-lg); background: var(--surface); overflow: hidden; box-shadow: var(--shadow); }
.live-bar { display: flex; align-items: center; gap: 12px; padding: 14px 20px; border-bottom: 1px solid var(--line); background: var(--surface-2); }
.live-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--warn); animation: pulse 1.8s infinite; }
.live-title { font-size: 13px; color: var(--muted); font-weight: 600; }
.live-chip { margin-left: auto; font-family: var(--mono); font-size: 11px; color: var(--green-2); border: 1px solid var(--line-strong); border-radius: 999px; padding: 3px 11px; }
.live-rows { padding: 22px 20px; min-height: 340px; display: flex; flex-direction: column; gap: 18px; }
.live-row { opacity: 0; transform: translateY(12px); transition: opacity 0.5s var(--ease), transform 0.5s var(--ease); }
.live-row.is-on { opacity: 1; transform: none; }
.live-row small { display: block; font-size: 10.5px; letter-spacing: 0.14em; color: var(--muted-2); text-transform: uppercase; }
.live-row p { font-size: 16px; color: var(--text); margin-top: 2px; }
.live-row p.translate { font-size: 14.5px; color: var(--green-2); }
.live-foot { display: flex; align-items: center; gap: 18px; padding: 18px 20px; border-top: 1px solid var(--line); }
.live-note { font-size: 12px; color: var(--muted-2); }

/* ---------- Act 6 三步 ---------- */
.act-start .head { margin-bottom: 34px; }
.steps-track { display: flex; gap: 24px; will-change: transform; }
.step-card {
  flex: 0 0 min(560px, 44vw); padding: 34px 32px; border: 1px solid var(--line); border-radius: var(--r-lg);
  background: linear-gradient(160deg, var(--surface), var(--bg-2));
  transition: transform 0.5s var(--ease), border-color 0.5s;
}
.step-card.is-focus { border-color: rgba(190, 219, 138, 0.34); transform: translateY(-8px); }
.step-no { display: grid; place-items: center; width: 44px; height: 44px; border-radius: 13px; background: var(--green); color: #10140c; font-weight: 900; font-size: 17px; margin-bottom: 20px; }
.step-card h3 { font-size: 22px; margin-bottom: 10px; }
.step-card p { color: var(--muted); font-size: 15px; }
.steps-progress { position: relative; height: 1px; margin-top: 40px; background: var(--line); overflow: hidden; }
.steps-progress i { position: absolute; inset: 0 auto 0 0; width: 33%; background: var(--green); transition: width 0.15s linear; }
.steps-hint { margin-top: 14px; font-size: 12.5px; color: var(--muted-2); }

/* ---------- Act 7 边界 ---------- */
.act-trust { padding: 150px 0; }
.trust-list { display: flex; flex-direction: column; }
.trust-list li { display: grid; grid-template-columns: 220px 1fr; gap: 26px; padding: 22px 0; border-top: 1px solid var(--line); }
.trust-list li:last-child { border-bottom: 1px solid var(--line); }
.trust-list b { font-size: 16px; color: var(--text); font-weight: 700; }
.trust-list span { color: var(--muted); font-size: 15px; }

/* ---------- Act 8 收尾 ---------- */
.act-finale .stage { align-items: center; text-align: center; }
.glow-final { position: absolute; left: 50%; top: 46%; transform: translate(-50%, -50%); width: 1100px; height: 760px; opacity: 0.4; }
.finale-inner { position: relative; z-index: 2; display: flex; flex-direction: column; align-items: center; gap: 26px; }
.finale-meta { color: var(--muted); font-size: 14px; }
.finale-notes { color: var(--muted-2); font-size: 12.5px; max-width: 46em; }

/* ---------- FAQ ---------- */
.act-faq { padding: 130px 0 150px; }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary {
  display: flex; align-items: center; justify-content: space-between; gap: 20px;
  padding: 22px 0; font-size: 16.5px; font-weight: 700; cursor: pointer; list-style: none;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: '+'; font-size: 22px; font-weight: 400; color: var(--green-2); transition: transform 0.3s var(--ease); }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details > div { padding: 0 0 24px; color: var(--muted); font-size: 15px; max-width: 62em; }

/* ---------- 页脚 ---------- */
.footer { border-top: 1px solid var(--line); background: #0b0e09; padding: 70px 0 28px; }
.footer-inner { display: flex; justify-content: space-between; gap: 60px; flex-wrap: wrap; }
.footer-brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 16px; margin-bottom: 18px; }
.footer-note { color: var(--muted-2); font-size: 12.5px; max-width: 52em; margin-bottom: 10px; }
/* 运营者信息与合规入口：按中国大陆网站惯例放在页脚 */
.footer-operator { margin: 16px 0 12px; display: flex; flex-wrap: wrap; gap: 6px 22px; }
.footer-operator p { margin: 0; font-size: 12.5px; color: #c9cfc0; }
.footer-operator span { color: #98a08e; margin-right: 8px; }
.footer-legal { display: flex; flex-wrap: wrap; gap: 8px 18px; }
.footer-legal a { font-size: 12.5px; color: #c9cfc0; border-bottom: 1px solid #353b2d; }
.footer-legal a:hover { color: var(--green); border-bottom-color: var(--green); }
.footer-links { display: flex; flex-direction: column; gap: 12px; }
.footer-links a { color: var(--muted); font-size: 14px; }
.footer-links a:hover { color: var(--green); }
.footer-base { display: flex; justify-content: space-between; gap: 16px; margin-top: 46px; padding-top: 22px; border-top: 1px solid var(--line); color: var(--muted-2); font-size: 12px; }

/* ---------- 回到顶部 ---------- */
.to-top {
  position: fixed; right: 26px; bottom: 26px; z-index: 40; width: 46px; height: 46px; border-radius: 50%;
  display: grid; place-items: center; background: var(--surface-2); color: var(--green);
  border: 1px solid var(--line-strong); transition: transform 0.2s var(--ease), opacity 0.2s;
}
.to-top[hidden] { display: none; }
.to-top .ic { transform: rotate(-90deg); }
.to-top:hover { transform: translateY(-3px); }

/* ---------- 响应式 ---------- */
@media (max-width: 1180px) {
  .container, .container.narrow { width: min(1320px, 100% - 64px); }
  .hero-grid { grid-template-columns: 1fr; gap: 46px; }
  .device-inner { transform: none; }
  .detail-grid { grid-template-columns: 150px minmax(0, 1fr); grid-template-areas: 'head head' 'rail screen' 'rail copy'; align-items: start; }
  .detail-copy { min-height: 210px; }
  /* Bento：中号屏两列 */
  .bento-memory, .bento-practice, .bento-orb { grid-column: span 6; }
  .bento-simple { grid-column: span 12; display: block; }
  .bento-simple .simple-word { font-size: 58px; letter-spacing: 10px; margin: 20px 0; }
  .bento-simple h3 { font-size: 22px; margin-bottom: 12px; }
}
@media (max-width: 900px) {
  .container, .container.narrow { width: min(1320px, 100% - 40px); }
  .nav-links { display: none; position: absolute; top: 100%; left: 0; right: 0; flex-direction: column; gap: 0; margin: 0; padding: 8px 20px 16px; background: rgba(11, 14, 9, 0.97); border-bottom: 1px solid var(--line); }
  .nav-links.is-open { display: flex; }
  .nav-links a { padding: 13px 0; border-bottom: 1px solid var(--line); }
  .nav-toggle { display: block; order: 3; }
  .nav .btn { margin-left: auto; order: 2; }
  /* 关掉 pin / scrub，改普通纵向流 */
  /* overflow:hidden 兜底：即使 overflow-x:clip 不被支持，光晕也不会撑宽文档 */
  .act-hero, .act-detail, .act-start, .act-finale, .act-demo { height: auto; overflow: hidden; }
  .stage { position: static; min-height: 0; padding: 110px 0 80px; overflow: visible; }
  .act-pain, .act-ability, .act-live, .act-trust, .act-faq { padding: 84px 0; }
  .scroll-hint { display: none; }
  /* 窄屏直接不要光晕：它是唯一会伸出视口的装饰，部分安卓浏览器/WebView
     会因此把布局视口撑宽（正文按更宽的宽度排版 → 右侧被切）。手机上不值得为它冒险。 */
  .glow { display: none; }
  /* Bento：手机单列，横排的示意图改成上下堆叠 */
  .bento-grid { grid-template-columns: 1fr; }
  .bento-card { padding: 24px; }
  .bento-reader, .bento-audio, .bento-memory, .bento-practice, .bento-orb, .bento-simple { grid-column: span 1; }
  .bento-reader { min-height: 300px; }
  .bento-reader > div { max-width: 100%; }
  .bento-reader h3 { font-size: 26px; }
  .bento-reader img { position: static; width: 118%; max-width: none; margin: 22px 0 -34px 12%; transform: rotate(-6deg); }
  .bento-audio .waveform { margin: 18px 0 10px; }
  .bento-memory, .bento-practice, .bento-orb { min-height: 0; }
  .practice-formula { margin: 26px 0; font-size: 24px; }
  .orb { margin: 26px auto 24px; }
  .bento-simple { display: block; padding-block: 26px; }
  .bento-simple .simple-word { font-size: 46px; letter-spacing: 8px; margin: 16px 0; }
  .bento-simple h3 { font-size: 21px; margin-bottom: 10px; }
  .detail-grid { grid-template-columns: 1fr; grid-template-areas: 'head' 'screen' 'copy' 'rail'; gap: 26px; }
  .rail { flex-direction: row; flex-wrap: wrap; gap: 8px; }
  .rail button { width: auto; padding: 8px 12px; border: 1px solid var(--line); border-radius: 999px; }
  .rail button i { display: none; }
  .rail button.is-active { border-color: var(--green); }
  .detail-copy { min-height: 300px; }
  .detail-item { position: static; display: none; }
  .detail-item.is-active { display: block; }

  /* 手机端「功能详解」：app.js 把 8 组「截图 + 说明」重排成普通纵向列表
     （.is-stacked）。不再随滚动切换——窄屏上一屏放不下，切换会让画面和文字
     在滚动中来回跳。桌面端完全不受影响。 */
  .detail-grid.is-stacked { display: flex; flex-direction: column; gap: 0; }
  .detail-grid.is-stacked .rail { display: none; }
  .detail-grid.is-stacked .head { margin-bottom: 22px; }
  .detail-grid.is-stacked .detail-shot {
    position: static; inset: auto; opacity: 1; transform: none; margin: 0 0 6px;
    aspect-ratio: 16 / 10; border: 1px solid var(--line-strong); border-radius: var(--r);
    overflow: hidden; background: #0b0e09;
  }
  .detail-grid.is-stacked .detail-shot img { transform: none; }
  /* 第 1、2 条用的是同一张截图：第 2 条换高一点的取景框 + 靠右裁切，露出 AI 面板，
     免得两条看起来一样。这里刻意不用 transform（手机上不留任何超出容器的变换框）。 */
  .detail-grid.is-stacked .detail-shot[data-i="1"] { aspect-ratio: 4 / 3; }
  .detail-grid.is-stacked .detail-shot[data-i="1"] img { object-fit: cover; object-position: 100% 0; }
  .detail-grid.is-stacked .detail-shot.fit-height img { object-fit: contain; transform: none; }
  .detail-grid.is-stacked .detail-item {
    position: static; inset: auto; opacity: 1; transform: none; pointer-events: auto;
    display: block; min-height: 0; margin: 0 0 34px;
  }
  .detail-grid.is-stacked .detail-item h3 { font-size: 20px; margin-bottom: 12px; }
  .detail-grid.is-stacked .detail-item li { font-size: 14px; margin-bottom: 10px; }
  .steps-track { flex-direction: column; transform: none !important; }
  .step-card { flex: 1 1 auto; }
  .step-card.is-focus { transform: none; }
  .trust-list li { grid-template-columns: 1fr; gap: 6px; }
  .live-foot { flex-wrap: wrap; gap: 12px; }
}
@media (max-width: 560px) {
  /* 手机上导航要给「下载 Android 版」让位：收紧间距、去掉按钮里的图标与「下载」前缀；
     品牌名做成可收缩的，任何情况下都不会把按钮和汉堡挤出屏幕（挤出去就会撑宽文档） */
  .nav-inner { gap: 10px; }
  .nav .btn .ic, .nav .cta-prefix { display: none; }
  .nav .btn { padding: 8px 14px; font-size: 13px; flex: none; }
  .nav-toggle { flex: none; }
  .brand { min-width: 0; }
  .brand-text { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
  .display { font-size: clamp(30px, 9vw, 42px); }
  .display-2 { font-size: clamp(24px, 7.4vw, 32px); }
  .hero-copy .lead { font-size: 16px; }
  .hero-cta .btn { width: 100%; }
  .btn-xl { padding: 15px 24px; font-size: 16px; }
  .detail-screen { aspect-ratio: 4 / 3; }
  .footer-base { flex-direction: column; gap: 6px; }
  /* 现场演示：手机上不是钉住的，改用点圆点切帧，滚动提示没有意义 */
  .demo-tabs button { padding: 9px 14px; font-size: 13px; }
  .demo-frame { aspect-ratio: 4 / 3; }
  .demo-caption { flex: 1 1 100%; }
  .demo-hint { display: none; }
}

/* 必须放在 max-width:560 之后：两条都会命中 ≤390 的屏，靠后的才生效。
   极窄屏（320–390）标题两行排不下，允许换行 + 缩小字号，避免几像素级的溢出
   被部分安卓浏览器放大成"整页右侧被切"。 */
@media (max-width: 390px) {
  .line > span { white-space: normal; }
  .display { font-size: clamp(26px, 8.4vw, 34px); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
  [data-fade], .pain-item { opacity: 1 !important; transform: none !important; }
  .line > span { transform: none !important; }
  .preloader { display: none !important; }
  .glow { animation: none !important; }
}