:root {
  /* 与桌面程序 frontend/src/index.css 保持一致 */
  --ink: #111318;
  --body: #3b4048;
  --muted: #6b7280;
  --faint: #9ca3af;
  --line: #e4e6ea;
  --line-soft: #eef0f2;
  --canvas: #f3f4f6;
  --surface: #ffffff;
  --surface-soft: #f8f9fa;
  --primary: #111318;
  --primary-hover: #2a2d33;
  --success: #059669;
  --warn: #b45309;
  --warn-soft: #fffbeb;
  --warn-line: #fde7b0;
  --night: #0a0b0d;
  --night-2: #131519;
  --night-line: #23262c;

  --font: "Segoe UI Variable Text", "Segoe UI", -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei UI", "Microsoft YaHei", system-ui, sans-serif;
  --display: "Segoe UI Variable Display", "Segoe UI", -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei UI", system-ui, sans-serif;
  --mono: "Cascadia Mono", Consolas, "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  --radius: 14px;
  --gutter: 24px;
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 64px; }
body {
  margin: 0;
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.6;
  color: var(--body);
  background: var(--surface);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}
h1, h2, h3, p, ul, ol, pre { margin: 0; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
code { font-family: var(--mono); font-size: .9em; padding: 1px 6px; border-radius: 6px; background: var(--canvas); color: var(--ink); }
:focus-visible { outline: 2px solid #1d4ed8; outline-offset: 2px; border-radius: 6px; }

.container { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 var(--gutter); }

/* ============ 按钮 ============ */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  height: 40px; padding: 0 18px; border: 1px solid var(--line); border-radius: 9px;
  color: var(--ink); background: var(--surface); font-size: 14px; font-weight: 600; white-space: nowrap;
  transition: background .15s, border-color .15s, transform .15s;
}
.btn:hover { border-color: #c9cdd3; background: var(--surface-soft); }
.btn:active { transform: translateY(1px); }
.btn.primary { border-color: var(--primary); color: #fff; background: var(--primary); }
.btn.primary:hover { border-color: var(--primary-hover); background: var(--primary-hover); }
.btn.ghost { border-color: transparent; background: transparent; }
.btn.ghost:hover { background: var(--canvas); }
.btn.small { height: 34px; padding: 0 13px; font-size: 13px; }
.btn.large { height: 46px; padding: 0 22px; font-size: 15px; }
.btn.xl { height: 54px; padding: 0 28px; font-size: 16px; border-radius: 11px; }

/* ============ 导航 ============ */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgb(255 255 255 / 82%);
  backdrop-filter: saturate(1.6) blur(14px);
  -webkit-backdrop-filter: saturate(1.6) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s;
}
.nav.scrolled { border-bottom-color: var(--line); }
.nav-inner { display: flex; align-items: center; gap: 28px; max-width: 1200px; height: 64px; margin: 0 auto; padding: 0 var(--gutter); }
.logo { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); font-weight: 700; font-size: 15px; letter-spacing: -.01em; }
.logo-mark { display: grid; place-items: center; width: 26px; height: 26px; border-radius: 7px; color: #fff; background: var(--primary); font-size: 13px; font-weight: 800; }
.logo-mark.inv { color: var(--night); background: #fff; }
/* 品牌名里突出 FlashTool（与桌面程序标题栏一致） */
.tool-chip {
  display: inline-flex; align-items: center; gap: 4px; height: 24px; margin-left: -4px; padding: 0 9px 0 7px;
  border-radius: 7px; color: #fff; background: linear-gradient(135deg, var(--ink), #2f343c);
  font-size: 13px; font-weight: 700; letter-spacing: .01em;
  box-shadow: inset 0 0 0 1px rgb(255 255 255 / 8%), 0 1px 2px rgb(15 23 42 / 18%);
}
.tool-chip svg { width: 12px; height: 12px; fill: #34d399; }
.tool-chip.inv { color: var(--night); background: #fff; box-shadow: none; }
.tool-chip.inv svg { fill: #059669; }
.nav-links { display: flex; gap: 4px; margin-right: auto; }
.nav-links a { padding: 6px 12px; border-radius: 8px; color: var(--muted); font-size: 14px; font-weight: 500; transition: color .15s, background .15s; }
.nav-links a:hover { color: var(--ink); background: var(--canvas); }
.nav-cta { display: flex; align-items: center; gap: 8px; }

/* ============ Hero ============ */
.hero { position: relative; justify-content: center; padding: 48px var(--gutter) 96px; text-align: center; overflow: hidden; }
.hero::before {
  /* 淡淡的点阵底纹，呼应开场的二进制 */
  content: ""; position: absolute; inset: 0; z-index: -1;
  background-image: radial-gradient(circle at 1px 1px, rgb(17 19 24 / 9%) 1px, transparent 0);
  background-size: 22px 22px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 42%, #000 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 42%, #000 30%, transparent 75%);
}
.hero-copy { width: 100%; max-width: 880px; margin: 0 auto; }
.pill {
  display: inline-flex; align-items: center; gap: 8px; height: 30px; padding: 0 13px;
  border: 1px solid var(--line); border-radius: 99px; background: var(--surface);
  color: var(--body); font-size: 13px; font-weight: 500;
  box-shadow: 0 1px 2px rgb(15 23 42 / 4%);
}
.pill-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--success); box-shadow: 0 0 0 3px rgb(5 150 105 / 15%); }
.hero-title {
  margin: 22px 0 18px;
  color: var(--ink);
  font-family: var(--display);
  font-size: clamp(46px, 9.2vw, 108px);
  font-weight: 700;
  line-height: 1.02;
  letter-spacing: -.045em;
}
.hero-title span { display: inline-block; }
.hero-title .soft { color: #8a909a; }
/* FlashTool：刷入进度条从左扫到右，再弹出闪电 */
.hero-title .flash { position: relative; color: var(--ink); }
.flash-bar {
  position: absolute; left: .03em; right: .03em; bottom: -.04em; height: .085em; overflow: hidden;
  border-radius: 99px; background: linear-gradient(90deg, #059669, #34d399 65%, #6ee7b7);
  box-shadow: 0 0 .22em rgb(52 211 153 / 45%);
  transform: scaleX(0); transform-origin: left center;
}
.flash-bar::after {
  content: ""; position: absolute; inset: 0; width: 35%;
  background: linear-gradient(90deg, transparent, rgb(255 255 255 / 85%), transparent);
  transform: translateX(-120%);
}
.flash-bolt {
  position: absolute; top: -.04em; right: -.5em; width: .46em; height: .46em;
  opacity: 0; transform: scale(.2) rotate(-25deg);
  filter: drop-shadow(0 0 .12em rgb(52 211 153 / 55%));
}
.flash-bolt svg { display: block; width: 100%; height: 100%; fill: #10b981; }
.hero-title.landed .flash-bar { transform: scaleX(1); transition: transform 1s cubic-bezier(.65,0,.35,1) .35s; }
.hero-title.landed .flash-bar::after { animation: flash-shine 4.5s ease-in-out 1.5s infinite; }
.hero-title.landed .flash-bolt { opacity: 1; transform: none; transition: transform .55s cubic-bezier(.34,1.56,.64,1) 1.15s, opacity .2s 1.15s; }
@keyframes flash-shine { 0% { transform: translateX(-120%); } 30%, 100% { transform: translateX(320%); } }
.hero-lead { max-width: 640px; margin: 0 auto; color: var(--muted); font-size: clamp(16px, 1.9vw, 19px); line-height: 1.65; }
.hero-actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; margin-top: 32px; }
.hero-meta { display: flex; flex-wrap: wrap; justify-content: center; gap: 6px 22px; margin-top: 22px; padding: 0; list-style: none; color: var(--faint); font-size: 13px; }
.hero-meta li { display: inline-flex; align-items: center; gap: 8px; }
.hero-meta li::before { content: ""; width: 4px; height: 4px; border-radius: 50%; background: #c4c8ce; }

/* 往下滑的提示 */
.scroll-hint { position: absolute; left: 50%; bottom: 32px; display: grid; place-items: start center; width: 24px; height: 38px; margin-left: -12px; padding-top: 7px; border: 1.5px solid #c9cdd3; border-radius: 99px; }
.scroll-hint span { width: 3px; height: 8px; border-radius: 3px; background: var(--muted); animation: wheel 1.8s ease-in-out infinite; }
@keyframes wheel { 0% { opacity: 0; transform: translateY(-3px); } 30% { opacity: 1; } 70%, 100% { opacity: 0; transform: translateY(10px); } }

/* ============ 整屏分页 ============ */
.page { position: relative; display: flex; flex-direction: column; justify-content: center; }
.dots {
  position: fixed; right: 22px; top: 50%; z-index: 40;
  display: flex; flex-direction: column; gap: 6px; transform: translateY(-50%);
}
.dot { position: relative; display: grid; place-items: center; width: 22px; height: 22px; }
.dot i { width: 7px; height: 7px; border-radius: 99px; background: rgb(17 19 24 / 22%); transition: height .3s cubic-bezier(.2,.7,.2,1), background .3s; }
.dot:hover i { background: rgb(17 19 24 / 50%); }
.dot.on i { height: 22px; background: var(--ink); }
.dot span {
  position: absolute; right: 30px; top: 50%; padding: 3px 9px; border-radius: 6px;
  color: #fff; background: var(--ink); font-size: 12px; font-weight: 600; white-space: nowrap;
  opacity: 0; transform: translate(6px, -50%); pointer-events: none; transition: opacity .15s, transform .15s;
}
.dot:hover span { opacity: 1; transform: translate(0, -50%); }
.dots.on-dark .dot i { background: rgb(255 255 255 / 28%); }
.dots.on-dark .dot.on i { background: #fff; }
.dots.on-dark .dot span { color: var(--ink); background: #fff; }

/* ============ 软件界面展示（台前调度式倾斜卡片） ============ */
.tour { padding: 28px var(--gutter) 24px; background: linear-gradient(180deg, var(--surface) 0%, #f6f7f9 100%); }
.tour-inner { width: 100%; max-width: 1280px; margin: 0 auto; }
.tour-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 24px; margin-bottom: 22px; }
.tour-head h2 { color: var(--ink); font-family: var(--display); font-size: clamp(26px, 3.2vw, 36px); font-weight: 700; line-height: 1.15; letter-spacing: -.03em; }
.tour-head .eyebrow { margin-bottom: 8px; }
.tour-note { flex: none; display: inline-flex; align-items: center; gap: 8px; color: var(--faint); font-size: 12.5px; }
.live-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--success); animation: pulse 2s ease-in-out infinite; }
@keyframes pulse { 50% { box-shadow: 0 0 0 4px rgb(5 150 105 / 18%); } }

.stage { --tw: 150px; --th: 101px; --ts: .153; --gap: 18px; display: flex; gap: 40px; align-items: flex-start; justify-content: center; }
.strip {
  flex: none; width: calc(var(--tw) * .9 + 28px); padding: 4px 0 14px 12px;
  display: flex; flex-direction: column;
  overflow-y: auto; overflow-x: hidden; scrollbar-width: none; overscroll-behavior: contain;
}
.strip::-webkit-scrollbar { display: none; }
.strip.scrollable { mask-image: linear-gradient(180deg, #000 calc(100% - 48px), transparent); -webkit-mask-image: linear-gradient(180deg, #000 calc(100% - 48px), transparent); }
.strip.scrollable.at-end { mask-image: none; -webkit-mask-image: none; }
.thumb-item { flex: none; height: calc(var(--th) + var(--gap)); transition: height .5s cubic-bezier(.2,.8,.2,1), opacity .35s; }
.thumb-item.is-active { height: 0; opacity: 0; pointer-events: none; }
/* 像台前调度一样：卡片绕左边缘转向主窗口，右侧向后退 */
.thumb {
  position: relative; display: block; width: var(--tw); height: var(--th); padding: 0;
  transform-origin: 0% 50%;
  /* 透视写在卡片自己的 transform 里：perspective 属性只作用于直接子元素，卡片隔了一层 */
  transform: perspective(560px) rotateY(34deg);
  transition: transform .5s cubic-bezier(.2,.85,.25,1), filter .3s;
}
.thumb-screen {
  position: absolute; inset: 0; overflow: hidden; border-radius: 8px; background: #f3f4f6;
  box-shadow: 0 0 0 1px rgb(15 23 42 / 10%), 0 16px 30px -12px rgb(15 23 42 / 42%), 0 4px 10px -4px rgb(15 23 42 / 18%);
}
.thumb-screen::after {
  /* 一点玻璃反光 */
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background: linear-gradient(110deg, rgb(255 255 255 / 0%) 40%, rgb(255 255 255 / 22%) 52%, rgb(255 255 255 / 0%) 64%);
}
.thumb-screen iframe { position: absolute; left: 0; top: 0; width: 980px; height: 660px; border: 0; transform: scale(var(--ts)); transform-origin: 0 0; pointer-events: none; }
.thumb .app-icon { position: absolute; left: -10px; bottom: -10px; z-index: 1; width: 30px; height: 30px; border-radius: 8px; box-shadow: 0 4px 10px -2px rgb(15 23 42 / 35%), 0 0 0 1.5px #fff; }
.thumb .app-icon svg { width: 16px; height: 16px; }
.thumb-tip {
  position: absolute; left: 28px; bottom: -8px; z-index: 1; padding: 3px 9px; border-radius: 7px;
  color: #fff; background: rgb(17 19 24 / 88%); font-size: 11.5px; font-weight: 600; white-space: nowrap;
  opacity: 0; transform: translateX(-4px); pointer-events: none; transition: opacity .15s, transform .15s;
}
.thumb:hover, .thumb:focus-visible { transform: perspective(560px) translateX(10px) rotateY(10deg) scale(1.06); }
.thumb:hover .thumb-tip, .thumb:focus-visible .thumb-tip { opacity: 1; transform: none; }
.strip:hover .thumb:not(:hover) { filter: brightness(.96) saturate(.85); }

.app-icon {
  display: grid; place-items: center; width: 44px; height: 44px; border-radius: 12px; color: #fff;
  background: linear-gradient(160deg, var(--c1), var(--c2));
  box-shadow: inset 0 1px 0 rgb(255 255 255 / 30%), 0 3px 8px -3px rgb(15 23 42 / 35%);
}
.app-icon svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 2.2; stroke-linecap: round; stroke-linejoin: round; }

.stage-main { flex: none; min-width: 0; }
.window-wrap { position: relative; width: 100%; transform-origin: 0 0; }
.window {
  /* 桌面程序窗口：980 × 660，无系统标题栏 */
  position: absolute; top: 0; left: 50%;
  width: 980px; height: 660px;
  transform-origin: top center;
  border-radius: 10px; overflow: hidden;
  background: #f3f4f6;
  box-shadow: 0 0 0 1px rgb(15 23 42 / 10%), 0 2px 4px rgb(15 23 42 / 4%), 0 28px 70px -12px rgb(15 23 42 / 28%), 0 60px 120px -40px rgb(15 23 42 / 22%);
}
.window iframe { display: block; width: 100%; height: 100%; border: 0; background: #f3f4f6; }
.window-loading { position: absolute; inset: 0; display: grid; place-items: center; background: #f3f4f6; opacity: 0; pointer-events: none; transition: opacity .18s; }
.window-loading.on { opacity: 1; }
.window-loading span { width: 22px; height: 22px; border: 2px solid var(--line); border-top-color: var(--ink); border-radius: 50%; animation: spin .7s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

.tour-caption { min-height: 46px; margin: 20px auto 0; text-align: left; transition: opacity .3s; }
.tour-caption strong { color: var(--ink); font-size: 15.5px; }
.tour-caption p { margin-top: 2px; color: var(--muted); font-size: 14px; }
.tour-caption.swap { opacity: 0; }

/* ============ 通用段落 ============ */
.section { padding: 96px 0; }
.section.alt { background: var(--surface-soft); border-top: 1px solid var(--line-soft); border-bottom: 1px solid var(--line-soft); }
.section-head { max-width: 640px; margin-bottom: 48px; }
.eyebrow { display: inline-block; margin-bottom: 12px; color: var(--muted); font-family: var(--mono); font-size: 12.5px; letter-spacing: .04em; text-transform: uppercase; }
.section h2 { color: var(--ink); font-family: var(--display); font-size: clamp(30px, 4.4vw, 46px); font-weight: 700; line-height: 1.12; letter-spacing: -.03em; }
.section-head p { margin-top: 14px; color: var(--muted); font-size: 16.5px; }

/* 功能 */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.feature { padding: 28px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); transition: transform .2s, box-shadow .2s, border-color .2s; }
.feature:hover { transform: translateY(-2px); border-color: #d6d9de; box-shadow: 0 14px 32px -16px rgb(15 23 42 / 18%); }
.f-icon { display: grid; place-items: center; width: 40px; height: 40px; border-radius: 10px; background: var(--canvas); color: var(--ink); }
.f-icon svg { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.feature h3 { margin-top: 22px; color: var(--ink); font-size: 17px; font-weight: 650; }
.feature p { margin-top: 8px; color: var(--muted); font-size: 14px; line-height: 1.65; }

/* 安全（深色） */
.section.dark { color: #a1a6af; background: var(--night); }
.section.dark h2 { color: #fff; }
.section.dark .eyebrow { color: #6b7280; }
.section.dark .section-head p { color: #9096a0; }
.section.dark code { color: #e5e7eb; background: #1d2026; }
.safety { position: relative; }
.checks { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; padding: 0; list-style: none; border: 1px solid var(--night-line); border-radius: var(--radius); overflow: hidden; background: var(--night-line); }
.checks li { display: flex; gap: 14px; padding: 26px; background: var(--night); }
.ck { flex: none; display: grid; place-items: center; width: 24px; height: 24px; border-radius: 50%; color: #34d399; background: rgb(52 211 153 / 12%); font-size: 13px; font-weight: 800; }
.checks strong { color: #f3f4f6; font-size: 15.5px; }
.checks p { margin-top: 4px; font-size: 14px; line-height: 1.6; }

/* 刷机包 */
.pkg-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.pkg { display: flex; flex-direction: column; gap: 14px; padding: 30px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.pkg header { display: flex; flex-direction: column; align-items: flex-start; gap: 12px; }
.pkg .tag { padding: 3px 9px; border-radius: 6px; color: var(--body); background: var(--canvas); font-family: var(--mono); font-size: 12px; }
.pkg h3 { color: var(--ink); font-size: 20px; font-weight: 650; letter-spacing: -.01em; }
.pkg p { color: var(--muted); font-size: 14.5px; }
.tree { margin-top: auto; padding: 18px 20px; border-radius: 10px; color: #b8bdc6; background: var(--night); font-family: var(--mono); font-size: 13px; line-height: 1.75; overflow-x: auto; }
.tree b { color: #fff; font-weight: 600; }

/* 下载 */
.download { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr); overflow: hidden; border: 1px solid var(--line); border-radius: 20px; background: var(--surface); box-shadow: 0 30px 80px -40px rgb(15 23 42 / 25%); }
.dl-main { padding: 52px; }
.dl-sub { margin-top: 14px; color: var(--muted); font-size: 16px; }
.dl-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }
.dl-meta { margin-top: 14px; color: var(--faint); font-family: var(--mono); font-size: 12.5px; }
.callout { display: flex; gap: 10px; margin-top: 32px; padding: 13px 15px; border: 1px solid var(--warn-line); border-radius: 10px; color: var(--warn); background: var(--warn-soft); font-size: 13.5px; line-height: 1.55; }
.callout svg { flex: none; margin-top: 2px; }
.dl-side { padding: 52px 44px; border-left: 1px solid var(--line); background: var(--surface-soft); }
.dl-side h3 { color: var(--ink); font-size: 14px; font-weight: 650; }
.dl-side h3 + * { margin-top: 12px; }
.req { display: grid; gap: 8px; margin-bottom: 32px; padding: 0; list-style: none; font-size: 14px; }
.req li { display: flex; align-items: center; gap: 10px; }
.req li::before { content: ""; flex: none; width: 16px; height: 16px; border-radius: 50%; background: var(--ink) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3E%3Cpath d='m4.5 8.2 2.2 2.2 4.8-4.8' fill='none' stroke='white' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / 16px no-repeat; }
.code { position: relative; }
.code pre { padding: 16px 18px; border-radius: 10px; color: #d1d5db; background: var(--night); font-family: var(--mono); font-size: 12.5px; line-height: 1.75; overflow-x: auto; }
.copy { position: absolute; top: 8px; right: 8px; height: 26px; padding: 0 10px; border-radius: 6px; color: #9ca3af; background: #1d2026; font-size: 12px; transition: color .15s, background .15s; }
.copy:hover { color: #fff; background: #2a2e36; }
.small-note { margin-top: 12px; color: var(--faint); font-size: 12.5px; }

/* 页脚（位于下载页底部） */
.page-last { justify-content: flex-start; padding-bottom: 0; }
.page-last > .container { margin-block: auto; padding-top: 24px; padding-bottom: 48px; }
.download-spacer { display: none; }
.footer { padding: 26px 0 22px; color: #8b9099; background: var(--night); }
.footer .logo { color: #fff; }
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 32px; }
.footer-brand { display: flex; align-items: center; gap: 20px; }
.footer-brand p { font-size: 13px; }
.footer-cols { display: flex; gap: 28px; }
.footer-cols div { display: flex; align-items: center; gap: 18px; font-size: 13.5px; }
.footer-cols span { color: #5c626c; font-size: 12px; }
.footer-cols a:hover { color: #fff; }
.footer-base { display: flex; justify-content: space-between; gap: 16px; margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--night-line); font-size: 12px; }
.replay { color: #8b9099; font-size: 12px; text-decoration: underline; text-underline-offset: 3px; }
.replay:hover { color: #fff; }

/* ============ 入场动画 ============ */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .7s cubic-bezier(.2,.7,.2,1), transform .7s cubic-bezier(.2,.7,.2,1); }
.reveal.in { opacity: 1; transform: none; }
.reveal-hero { opacity: 0; transform: translateY(14px); }
.ready .reveal-hero { opacity: 1; transform: none; transition: opacity .8s cubic-bezier(.2,.7,.2,1), transform .8s cubic-bezier(.2,.7,.2,1); }
.ready .hero-lead { transition-delay: .06s; }
.ready .hero-actions { transition-delay: .14s; }
.ready .hero-meta { transition-delay: .2s; }
.ready .scroll-hint { transition-delay: .5s; }
.no-intro:not(.ready) .hero-title { opacity: 0; }
.no-intro.ready .hero-title { animation: title-in .9s cubic-bezier(.2,.7,.2,1); }
@keyframes title-in { from { opacity: 0; transform: translateY(10px); filter: blur(6px); } }

/* ============ 开场：二进制汇成标题 ============ */
.intro-layer { display: none; }
.intro .intro-layer { position: fixed; inset: 0; z-index: 100; display: block; overflow: hidden; background: var(--night); transition: opacity .35s ease; }
.intro-layer.gone { opacity: 0; pointer-events: none; }
.intro body { overflow: hidden; }
.intro .hero-title [data-intro] { opacity: 0; }
.intro .hero-title.landed [data-intro] { opacity: 1; transition: opacity .8s cubic-bezier(.4,0,.2,1); }
#intro-canvas { position: absolute; inset: 0; width: 100%; height: 100%; }
.intro-hud {
  position: absolute; left: 28px; top: 24px;
  color: #c9ced6; font-family: var(--mono); font-size: 12.5px; line-height: 1.8;
  text-shadow: 0 0 12px rgb(0 0 0 / 80%);
  transition: opacity .4s;
}
.intro-hud .hud-dim { color: #5c626c; }
.intro-hud .hud-prompt { color: #34d399; }
#hud-status.ok { color: #34d399; }
.intro-bar { position: absolute; left: 0; right: 0; bottom: 0; height: 2px; background: rgb(255 255 255 / 6%); transition: opacity .4s; }
.intro-bar span { display: block; width: 0; height: 100%; background: #fff; box-shadow: 0 0 12px rgb(255 255 255 / 70%); }
.intro-skip {
  position: absolute; right: 24px; bottom: 22px; height: 32px; padding: 0 14px;
  border: 1px solid rgb(255 255 255 / 14%); border-radius: 99px;
  color: #9ca3af; background: rgb(10 11 13 / 60%); font-size: 12.5px;
  transition: color .15s, border-color .15s, opacity .3s;
}
.intro-skip:hover { color: #fff; border-color: rgb(255 255 255 / 35%); }
.intro-layer.fading .intro-hud, .intro-layer.fading .intro-bar, .intro-layer.fading .intro-skip { opacity: 0; }

/* ============ 响应式 ============ */
/* 大屏：每一页占满一屏，滑过一定距离后整页切换 */
@media (min-width: 900px) and (min-height: 620px) {
  html { scroll-snap-type: y mandatory; }
  .page { min-height: calc(100vh - 64px); min-height: calc(100dvh - 64px); scroll-snap-align: start; scroll-snap-stop: always; }
  .page.section:not(.page-last) { padding: 56px 0; }
}
/* 矮一些的屏幕：收紧留白，让每页仍然一屏放下 */
@media (min-width: 900px) and (min-height: 620px) and (max-height: 880px) {
  .page.section:not(.page-last) { padding: 32px 0; }
  .section-head { margin-bottom: 28px; }
  .section h2 { font-size: clamp(28px, 3.6vw, 38px); }
  .section-head p { margin-top: 10px; font-size: 15.5px; }
  .feature { padding: 20px 22px; }
  .feature h3 { margin-top: 14px; }
  .checks li { padding: 20px 22px; }
  .pkg { padding: 24px; }
  .dl-main { padding: 36px 40px; }
  .dl-side { padding: 36px 36px; }
  .dl-actions { margin-top: 24px; }
  .callout { margin-top: 22px; }
  .req { margin-bottom: 22px; }
  .page-last > .container { padding-top: 16px; padding-bottom: 28px; }
}
@media (max-width: 1100px) {
  .footer-brand p { display: none; }
}
@media (max-width: 960px) {
  .feature-grid, .checks { grid-template-columns: 1fr 1fr; }
  .download { grid-template-columns: minmax(0, 1fr); }
  .dl-side { border-left: 0; border-top: 1px solid var(--line); }
}
@media (max-width: 899px) {
  .dots, .scroll-hint { display: none; }
  .hero { padding: 72px var(--gutter) 88px; }
  .tour { padding: 64px var(--gutter); }
  .stage { flex-direction: column; gap: 14px; }
  .strip {
    order: 2; width: 100%; padding: 6px 4px 14px 12px; flex-direction: row; gap: 18px;
    overflow-x: auto; overflow-y: hidden;
  }
  .thumb-item { height: auto; width: var(--tw); transition: width .4s, opacity .3s; }
  .thumb-item.is-active { width: 0; margin-right: -18px; height: auto; }
  .thumb { transform: none; }
  .thumb:hover { transform: translateY(-2px); }
  .thumb-tip { opacity: 1; transform: none; }
  .stage-main { width: 100%; }
  .footer-inner { flex-direction: column; align-items: flex-start; gap: 16px; }
  .footer-cols { flex-wrap: wrap; gap: 12px 28px; }
}
@media (max-width: 680px) {
  :root { --gutter: 16px; }
  .hide-sm { display: none; }
  .nav-links { display: none; }
  .nav-cta { margin-left: auto; }
  .tour-head { flex-direction: column; align-items: flex-start; gap: 8px; }
  .section { padding: 72px 0; }
  .section-head { margin-bottom: 36px; }
  .feature-grid, .checks, .pkg-grid { grid-template-columns: minmax(0, 1fr); }
  .dl-main, .dl-side { padding: 32px 22px; }
  .pkg { padding: 22px; }
  .footer-base { flex-direction: column; }
  .intro-hud { left: 16px; top: 16px; font-size: 11.5px; }
}
@media (prefers-reduced-motion: reduce) {
  .reveal, .reveal-hero { opacity: 1; transform: none; transition: none; }
  .hero-title.landed .flash-bar, .hero-title.landed .flash-bolt { transition: none; }
  .hero-title.landed .flash-bar::after { animation: none; }
  html { scroll-behavior: auto; }
  .thumb, .thumb-item, .window-wrap { transition: none !important; }
}