/* 妙算 AI 品牌官网 — 深海蓝底、清透青蓝强调、少量明蓝过渡、银白文字 */

:root {
  --bg: #081525;
  --surface: #102842;
  --blue: #3978F6;
  --accent: #52DAE5;
  --accent-ink: #06121F;
  --text: #F3F7FD;
  --muted: #B6C7DB;
  --line: rgba(182, 199, 219, 0.16);
  --line-strong: rgba(182, 199, 219, 0.34);
  --focus: #52DAE5;
  --muted-soft: rgba(182, 199, 219, 0.82);
  /* 2026-10-21 光效层（见文件末尾「霓虹光效」）：紫蓝光与霓虹描边 */
  --violet: #7B5CFF;
  --neon-edge: rgba(122, 170, 255, 0.55);
  --neon-glow: 0 0 0 1px rgba(82, 218, 229, 0.18), 0 0 18px rgba(82, 218, 229, 0.22), 0 0 60px -10px rgba(123, 92, 255, 0.55);
  /* 两端渐隐的细线，用 border-image 套在 1px 边框上 */
  --hairline: linear-gradient(90deg, transparent, rgba(182, 199, 219, 0.18) 8%, rgba(182, 199, 219, 0.18) 92%, transparent) 1;

  --font: "Noto Sans SC", system-ui, -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB",
          "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  --font-display: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
                  "Noto Sans CJK SC", system-ui, sans-serif;
  /* 长文正文（.static-page article）用它：那些字不进子集字体，首页访客不必为没人点开的
     法律文本多下 54 KB 字体。不能只靠 --font 的回退——回退是逐字符的，子集里有的字出
     Noto、没有的出系统字体，同一行里两种字体混排。
     **具名的简体中文字体必须排在 system-ui 前面**（与 --font-display 同序）：Windows 上
     system-ui 跟系统界面语言走、不跟页面的 lang 走，日文 / 韩文 / 繁体界面下取到的是
     Yu Gothic UI / Malgun Gothic / JhengHei UI——有通用汉字、没有简体专用字，后者逐字符
     落到微软雅黑，又是混排，共用字还会显示成日文字形。--font 里 system-ui 排第二没出过
     事，只因为子集盖住了首页全部文字、它从没真正出过中文字形；这里整段正文都靠它。 */
  --font-system: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC",
                 system-ui, -apple-system, "Segoe UI", sans-serif;

  --gutter: 20px;
  --header-h: 56px;   /* 手机上页眉常驻，64px 在 320 宽机型上占掉 11% 视口 */
  --radius: 16px;
  --content-max: 1120px;
}
@media (min-width: 768px) { :root { --gutter: 24px; --header-h: 72px; } }
@media (min-width: 1024px) { :root { --gutter: 32px; --header-h: 76px; } }

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }

html { scroll-padding-top: calc(var(--header-h) + 12px); -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.75;
  padding-left: env(safe-area-inset-left);
  padding-right: env(safe-area-inset-right);
}
@media (min-width: 1024px) { body { font-size: 17px; } }

img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-underline-offset: 0.18em; }
a:hover { color: var(--text); }
h1, h2, h3 { margin: 0; font-weight: 600; font-family: var(--font-display); }
h1, .section-title, .vision-statement { hanging-punctuation: allow-end; }
p { margin: 0; }
ul, ol { margin: 0; padding: 0; }
ul[role="list"] { list-style: none; }
.nowrap { white-space: nowrap; }

:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; border-radius: 4px; }

.skip-link {
  position: absolute; left: var(--gutter); top: -100px;
  padding: 10px 14px; background: var(--accent); color: var(--accent-ink);
  border-radius: 8px; z-index: 100; text-decoration: none; font-weight: 600;
}
.skip-link:focus { top: 8px; }
/* main 带 tabindex=-1 只为接住跳转链接的焦点，不是可交互元素，不画焦点框 */
#main:focus { outline: none; }

.container { width: 100%; max-width: var(--content-max); margin: 0 auto; padding-left: var(--gutter); padding-right: var(--gutter); }
.container-hero { max-width: 860px; }
.container-narrow { max-width: 720px; }

/* ---------- 按钮与链接 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 50px; padding: 13px 32px;
  border-radius: 12px; border: 1px solid transparent;
  font: inherit; font-weight: 600; letter-spacing: 0.02em; text-decoration: none; cursor: pointer;
  white-space: normal; text-align: center;
  transition: color 180ms ease, border-color 180ms ease, background-color 180ms ease, box-shadow 220ms ease, transform 220ms ease;
}
.btn-primary {
  background: linear-gradient(180deg, #66E0EA, #4CD3DF); color: var(--accent-ink); border-color: rgba(255, 255, 255, 0.14);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.22), 0 6px 18px -12px rgba(82, 218, 229, 0.4);
}
.btn-primary:hover {
  background: linear-gradient(180deg, #86E9F0, #5EDDE7); color: var(--accent-ink);
  transform: translateY(-1px);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.28), 0 16px 32px -16px rgba(82, 218, 229, 0.6);
}
.btn-primary:active { transform: translateY(0); }
.btn-secondary { background: transparent; color: var(--text); border-color: var(--line-strong); }
.btn-secondary:hover { border-color: var(--accent); }
.btn-ghost { background: transparent; color: var(--text); border-color: var(--line-strong); font-weight: 500; }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn-small { min-height: 40px; padding: 8px 16px; font-size: 15px; }
.text-link {
  position: relative;
  display: inline-flex; align-items: center; gap: 6px; min-height: 44px; padding: 0 8px;
  color: var(--muted); font-weight: 500;
  text-decoration: underline; text-decoration-color: rgba(182, 199, 219, 0.45); text-decoration-thickness: 1px; text-underline-offset: 0.3em;
  transition: color 180ms ease, text-decoration-color 180ms ease;
}
/* 悬停时青蓝下划线从左向右延展，静态细线同时淡出 */
.text-link::after {
  content: ""; position: absolute; left: 8px; right: 8px; top: calc(50% + 0.78em); height: 1px;
  background: var(--accent); transform: scaleX(0); transform-origin: left center; transition: transform 260ms cubic-bezier(0.2, 0.7, 0.2, 1);
}
.text-link:hover { color: var(--accent); text-decoration-color: transparent; }
.text-link:hover::after { transform: scaleX(1); }

/* ---------- 顶栏 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: transparent; border-bottom: 1px solid transparent;
  padding-top: env(safe-area-inset-top);
  transition: background-color 240ms ease, border-color 240ms ease;
}
.site-header.is-scrolled { background: rgba(8, 21, 37, 0.84); backdrop-filter: blur(14px); border-bottom-color: var(--line); }
@media (max-height: 520px) { .site-header { position: static; } }
.header-inner { min-height: var(--header-h); display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; font-weight: 600; min-height: 44px; }
.brand img { width: 30px; height: 30px; display: block; }
.brand-name { font-family: var(--font-display); font-size: 18px; letter-spacing: 0.02em; }
@media (min-width: 768px) { .brand .brand-name { font-size: 20px; } }
.site-nav { display: flex; align-items: center; gap: 6px; }
.nav-link {
  display: none; color: var(--muted); text-decoration: none; font-size: 15px;
  padding: 10px 14px; min-height: 44px; align-items: center; border-radius: 8px; transition: color 180ms ease;
}
.nav-link:hover { color: var(--text); }
@media (min-width: 768px) { .nav-link { display: inline-flex; } .site-nav { gap: 12px; } }

/* ---------- 品牌首屏：宽而柔的蓝青过渡 ---------- */
.hero { position: relative; padding-block: 44px 8px; overflow: hidden; }
/* 标题背后极淡的 MS 字形轮廓：只让人隐约感到有形状 */
.hero-glyph {
  display: none; position: absolute; left: 50%; top: 50%; width: min(1500px, 120vw); aspect-ratio: 1400 / 817; pointer-events: none; z-index: 0;
  transform: translate(-50%, -52%);
  background: url("assets/brand/ms-glyph-outline.png") center / contain no-repeat;
  opacity: 0.035;
  /* 只留两侧，标题与说明背后保持干净 */
  -webkit-mask-image: linear-gradient(90deg, #000 0%, #000 18%, transparent 36%, transparent 64%, #000 82%, #000 100%), linear-gradient(180deg, transparent 0%, #000 25%, #000 75%, transparent 100%);
  -webkit-mask-composite: source-in;
  mask-image: linear-gradient(90deg, #000 0%, #000 18%, transparent 36%, transparent 64%, #000 82%, #000 100%), linear-gradient(180deg, transparent 0%, #000 25%, #000 75%, transparent 100%);
  mask-composite: intersect;
}
@media (min-width: 1024px) { .hero-glyph { display: block; } }
.hero::before {
  content: ""; position: absolute; inset: -80px 0 0 0; pointer-events: none; z-index: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%, rgba(57, 120, 246, 0.34), transparent 70%),
    radial-gradient(ellipse 70% 50% at 50% 42%, rgba(82, 218, 229, 0.14), transparent 72%),
    linear-gradient(180deg, rgba(16, 40, 66, 0.8) 0%, rgba(8, 21, 37, 0) 100%);
}
.container-hero {
  position: relative; z-index: 1;
  display: flex; flex-direction: column; align-items: center; text-align: center;
}
@media (prefers-reduced-motion: no-preference) {
  .container-hero { animation: hero-rise 700ms cubic-bezier(0.2, 0.7, 0.2, 1) both; }
  @keyframes hero-rise { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }
}
.eyebrow { color: var(--accent); font-size: 14px; font-weight: 500; letter-spacing: 0.02em; margin-bottom: 16px; }
/* 主标题两层：品牌名（.h1-brand，银白实色）在前，口号（.h1-slogan，末段渐变）在后；h1 自身的字号即口号字号 */
h1 {
  display: grid; gap: 10px; justify-items: center;
  font-size: clamp(27px, 7.6vw, 30px); line-height: 1.22; letter-spacing: -0.02em; font-weight: 600; text-wrap: balance;
}
h1 .h1-brand { display: block; font-size: clamp(36px, 10.2vw, 40px); line-height: 1.1; letter-spacing: 0; color: var(--text); }
.h1-slogan { display: block; }
@media (max-width: 767px) { .h1-slogan .nowrap { display: block; } }
.h1-lead { color: var(--text); }
.h1-emph {
  background: linear-gradient(90deg, #F3F7FD 0%, #BFEFF5 55%, #52DAE5 100%);
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.lead { white-space: pre-line; color: var(--muted); font-size: 16px; line-height: 1.65; margin-top: 18px; max-width: 32em; }
.lead-narrow { display: none; }
@media (max-width: 767px) {
  .hero.has-mobile-intro .lead-wide { display: none; }
  .hero.has-mobile-intro .lead-narrow { display: block; }
}
.hero-actions { display: flex; flex-direction: column; align-items: center; gap: 6px; margin-top: 26px; width: 100%; }
.hero-actions .btn { min-height: 50px; }
.hero-actions .btn { width: 100%; }
@media (max-width: 359px) {
  .lead { font-size: 15px; }
  .ability { grid-template-columns: 72px 1fr; column-gap: 14px; }
  .ability-figure { width: 72px; }
}
@media (min-width: 480px) {
  .hero-actions { flex-direction: row; justify-content: center; gap: 18px; width: auto; }
  .hero-actions .btn { width: auto; min-width: 200px; }
}
@media (min-width: 768px) {
  .hero { padding-block: 80px 24px; }
  h1 { font-size: 34px; gap: 12px; }
  h1 .h1-brand { font-size: 56px; }
  .lead { font-size: 18px; line-height: 1.75; margin-top: 22px; }
  .eyebrow { font-size: 14px; letter-spacing: 0.06em; margin-bottom: 22px; }
  .hero-actions { gap: 12px; margin-top: 34px; }
}
@media (min-width: 1024px) {
  .hero { padding-block: 116px 56px; }
  h1 { font-size: clamp(36px, 2.8vw, 40px); gap: 14px; line-height: 1.15; }
  h1 .h1-brand { font-size: clamp(68px, 5.2vw, 76px); line-height: 1.05; letter-spacing: -0.02em; }
  .lead { font-size: 19px; margin-top: 26px; }
  .hero-actions { margin-top: 44px; }
}

/* ---------- 桌面首屏：左文字、右循环演示，下方宣传数字栏 ----------
   只在 ≥1024px 生效。手机首屏录进了新手指引视频，一个像素都不能变：.hero-visual 与 .hero-stats
   在 1024px 以下 display: none，不占位；手机的数字栏是「认识妙算」里的 #stats-about。 */
.hero-visual, .hero-stats { display: none; }
.hero-visual-toggle { font: inherit; font-size: 14px; }
@media (min-width: 1024px) {
  .hero { padding-block: 88px 40px; }
  .container-hero {
    max-width: var(--content-max);
    display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 6fr); column-gap: 56px;
    align-items: center; text-align: left;
  }
  .container-hero > * { grid-column: 1; }
  .container-hero h1 { justify-items: start; }
  .container-hero .lead { max-width: 26em; }
  .container-hero .hero-actions { justify-content: flex-start; }
  .hero-visual { display: block; grid-column: 2; grid-row: 1 / span 4; position: relative; }
  .hero-visual[hidden] { display: none; }
  .hero-visual-tag {
    display: inline-flex; align-items: center; gap: 8px; margin-bottom: 14px;
    color: var(--accent); font-size: 14px; font-weight: 500; letter-spacing: 0.02em;
  }
  .hero-visual-tag::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 0 4px rgba(82, 218, 229, 0.18); }
  .hero-visual-tag:empty { display: none; }
  .hero-screen {
    position: relative; border-radius: 18px; overflow: hidden; background: var(--surface);
    border: 1px solid rgba(82, 218, 229, 0.28);
    box-shadow: 0 0 0 6px rgba(57, 120, 246, 0.08), 0 32px 80px -24px rgba(57, 120, 246, 0.6), 0 12px 40px -12px rgba(82, 218, 229, 0.25);
  }
  .hero-screen video { display: block; width: 100%; height: auto; aspect-ratio: 16 / 9; }
  .hero-visual-toggle {
    position: absolute; right: 14px; bottom: 14px; min-height: 36px; padding: 0 14px;
    border-radius: 999px; border: 1px solid rgba(243, 247, 253, 0.28); background: rgba(8, 21, 37, 0.72);
    color: var(--text); font: inherit; font-size: 14px; cursor: pointer;
    transition: background-color 180ms ease, border-color 180ms ease;
  }
  .hero-visual-toggle:hover { background: rgba(8, 21, 37, 0.92); border-color: rgba(82, 218, 229, 0.6); }
  .hero-visual-toggle[hidden] { display: none; }
  .hero-stats { display: block; position: relative; z-index: 1; margin-top: 64px; }
}

/* ---------- 宣传数字栏（config.js 的 brand.stats）----------
   手机：「认识妙算」介绍之后，三行（图标 | 数字 + 名称）。768px 起三列一排，桌面放在首屏下方。 */
.stats[hidden] { display: none; }
.stats {
  position: relative; border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(16, 40, 66, 0.92), rgba(16, 40, 66, 0.6));
  border: 1px solid rgba(82, 218, 229, 0.22);
  box-shadow: inset 0 1px 0 rgba(243, 247, 253, 0.06), 0 24px 60px -30px rgba(57, 120, 246, 0.55);
  padding: 6px 18px 14px;
}
.stats-list { display: grid; }
.stat { display: grid; grid-template-columns: 48px 1fr; column-gap: 16px; align-items: center; padding: 14px 0; }
.stat + .stat { border-top: 1px solid transparent; border-image: var(--hairline); }
.stat-icon {
  width: 48px; height: 48px; border-radius: 50%; display: grid; place-items: center; color: var(--text);
  background: radial-gradient(circle at 30% 25%, rgba(82, 218, 229, 0.55), rgba(57, 120, 246, 0.85) 60%, rgba(32, 72, 170, 0.95));
  box-shadow: 0 8px 24px -8px rgba(57, 120, 246, 0.8), inset 0 1px 0 rgba(255, 255, 255, 0.25);
}
.stat-icon svg { width: 22px; height: 22px; }
.stat-body { min-width: 0; }
.stat-value {
  font-family: var(--font-display); font-weight: 600; font-size: 28px; line-height: 1.15; letter-spacing: -0.01em;
  font-variant-numeric: tabular-nums;
  background: linear-gradient(90deg, #F3F7FD 0%, #BFEFF5 60%, #52DAE5 100%);
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.stat-unit { font-size: 0.62em; margin-left: 2px; letter-spacing: 0; }
.stat-label { color: var(--muted); font-size: 15px; line-height: 1.5; margin-top: 2px; }
.stats-note { color: var(--muted-soft); font-size: 14px; line-height: 1.5; text-align: right; }
.about-stats { margin-top: 28px; }
@media (min-width: 768px) {
  .stats { padding: 26px 32px 18px; }
  .stats-list { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .stat { padding: 4px 0 4px 28px; column-gap: 18px; grid-template-columns: 56px 1fr; }
  .stat:first-child { padding-left: 0; }
  .stat + .stat { border-top: 0; border-image: none; border-left: 1px solid rgba(182, 199, 219, 0.16); }
  .stat-icon { width: 56px; height: 56px; }
  .stat-icon svg { width: 26px; height: 26px; }
  .stat-value { font-size: 34px; }
  .stats-note { margin-top: 12px; }
  .about-stats { margin-top: 36px; }
  /* 四格时平板排成两行两列：每行第一格不要左边线 */
  .stats-list.stats-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); row-gap: 22px; }
  .stats-4 .stat:nth-child(odd) { padding-left: 0; border-left: 0; }
}
@media (min-width: 1024px) {
  .about-stats { display: none; }
  .stats { padding: 30px 40px 20px; }
  .stat-value { font-size: 40px; }
  .stat { padding-left: 36px; }
  /* 四格时桌面一排四个，数字与图标略收小，3,860万+ 才放得下 */
  .stats-list.stats-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); row-gap: 0; }
  .stats-4 .stat { padding-left: 26px; column-gap: 14px; grid-template-columns: 52px 1fr; }
  .stats-4 .stat:first-child { padding-left: 0; }
  .stats-4 .stat:nth-child(3) { padding-left: 26px; border-left: 1px solid rgba(182, 199, 219, 0.16); }
  .stats-4 .stat-icon { width: 52px; height: 52px; }
  .stats-4 .stat-value { font-size: 36px; }
}

/* 手机横屏：压缩首屏高度，让主按钮留在第一屏。放在宽度断点之后，保证覆盖 768px 以上的字号 */
@media (max-height: 520px) and (orientation: landscape) {
  .hero { padding-block: 24px 12px; }
  .eyebrow { margin-bottom: 12px; }
  h1 { font-size: 24px; gap: 4px; line-height: 1.2; }
  h1 .h1-brand { font-size: 36px; }
  .lead { margin-top: 10px; font-size: 15px; line-height: 1.6; }
  .hero-actions { margin-top: 16px; }
  .hero-glyph { opacity: 0.035; }
}

/* ---------- 通用区块 ---------- */
.section { padding-block: 56px; }
@media (min-width: 768px) { .section { padding-block: 96px; } }
.section-title { font-size: clamp(26px, 6vw, 30px); line-height: 1.3; letter-spacing: -0.01em; text-wrap: balance; }
.section-title-center { text-align: center; }
.about-head .section-title { white-space: pre-line; }
.section-intro { white-space: pre-line; color: var(--muted); font-size: 16px; line-height: 1.7; margin-top: 14px; max-width: 30em; }
.hairline-top { border-top: 1px solid transparent; border-image: var(--hairline); }
@media (min-width: 768px) { .section-title { font-size: 32px; } }
@media (min-width: 1024px) { .section-title { font-size: 36px; } .section-intro { font-size: 17px; } }
@media (max-width: 479px) { .section-intro { white-space: normal; } }

/* ---------- 认识妙算：标题与介绍 → 演示视频 + 三项能力 → 统一说明 ----------
   手机是一列。标题与介绍的字号、间距与 2026-10-20 改版前逐像素一致：手机首屏下方露出的就是这两段，
   三段新手指引视频的第 1 步录到了它们（用户当天要求，改了要重做视频）。桌面上标题与介绍并排，
   下面左视频、右三项能力。 */
.section-about { padding-top: 40px; position: relative; }
/* 中段光区：一层很大很慢的深蓝径向光，从能力区一直铺到横幅，让页面有明暗节律 */
.section-about::before {
  content: ""; position: absolute; inset: 0 0 -45% 0;
  background: radial-gradient(ellipse 70% 42% at 50% 45%, rgba(57, 120, 246, 0.13), transparent 70%);
  pointer-events: none; z-index: 0;
}
.section-about > .container { position: relative; z-index: 1; }
.about-body { display: grid; gap: 32px; margin-top: 28px; }
.demo { margin: 0; display: grid; gap: 10px; min-width: 0; }
.demo-caption { color: var(--muted-soft); font-size: 14px; line-height: 1.6; text-wrap: pretty; }
.demo-caption:empty { display: none; }
/* 视频外框：首页演示与教学视频共用。先按 16:9 占位，封面图下来之前不塌成浏览器默认的 300×150 */
.video-frame {
  border: 1px solid rgba(82, 218, 229, 0.18); border-radius: 12px; overflow: hidden; background: var(--surface);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.10), 0 30px 60px -40px rgba(57, 120, 246, 0.55);
}
.video-frame video { display: block; width: 100%; height: auto; aspect-ratio: 16 / 9; background: var(--surface); }
.ability-list { display: grid; gap: 0; border-top: 1px solid transparent; border-image: var(--hairline); }
.ability { display: grid; grid-template-columns: 84px 1fr; column-gap: 18px; align-items: center; padding: 20px 0; border-bottom: 1px solid transparent; border-image: var(--hairline); }
.ability-figure { width: 84px; color: var(--accent); display: block; }
.ability-figure svg { width: 100%; height: auto; display: block; }
/* 悬停时线条从头描到尾（pathLength 归一化后 dasharray 用 1）；动画结束不保留状态，不支持 pathLength 的浏览器只会短暂闪一下 */
@media (hover: hover) {
  .ability:hover .ability-figure :is(path, rect, circle)[pathLength] { animation: figure-draw 720ms cubic-bezier(0.3, 0.6, 0.2, 1); }
  @keyframes figure-draw { from { stroke-dasharray: 1; stroke-dashoffset: 1; } to { stroke-dasharray: 1; stroke-dashoffset: 0; } }
}
.ability h3 { font-size: 18px; line-height: 1.35; }
.ability p { color: var(--muted-soft); font-size: 15px; line-height: 1.65; margin-top: 4px; max-width: 28em; }
.about-note { color: var(--muted-soft); font-size: 14px; line-height: 1.7; margin-top: 18px; max-width: 40em; }
.about-note:empty { display: none; }
@media (min-width: 768px) {
  .about-body { gap: 40px; margin-top: 36px; }
  .video-frame { border-radius: var(--radius); }
  .demo-caption { font-size: 15px; }
  .ability { padding: 26px 0; }
  .ability h3 { font-size: 19px; }
  .ability p { font-size: 16px; }
  .about-note { font-size: 15px; }
}
@media (min-width: 1024px) {
  .section-about { padding-top: 64px; }
  .about-head { display: grid; grid-template-columns: 5fr 7fr; gap: 72px; align-items: end; }
  /* 只在桌面上避免末行剩一两个字：手机上这段的换行是视频里录到的样子，不动 */
  .about-head .section-intro { margin-top: 0; text-wrap: pretty; }
  /* 演示视频在桌面首屏已经循环播放，这里不再重复；三项能力改成一排三列 */
  .about-body { margin-top: 48px; }
  .about-body .demo { display: none; }
  .ability-list { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 40px; border-top: 0; border-image: none; }
  .ability-list .ability { grid-template-columns: 1fr; row-gap: 14px; border-top: 1px solid transparent; border-image: var(--hairline); border-bottom: 0; align-items: start; }
  .ability-list .ability p { text-wrap: pretty; }
  /* 能力列比改版前窄（右侧 5 份），示意图维持手机上的 84px */
  .ability { column-gap: 22px; padding: 22px 0; }
  .about-note { margin-top: 32px; }
}

/* ---------- 3 分钟上手：教学视频（按游戏切换）+ 七步 ----------
   手机一列：切换 → 视频 → 说明 → 七步（竖向时间线）→ 下载按钮。桌面：七步横排在上，视频居中在下，按钮居中。
   视频就是新手指引页那三段，只引用不复制（config.js 的 product.tutorial）。 */
.section-tutorial { padding-bottom: 16px; }
.section-tutorial .section-intro { max-width: 40em; text-wrap: pretty; }
.tutorial-emph { color: var(--accent); }
.tutorial-layout { display: grid; gap: 32px; margin-top: 24px; }
.tutorial-player { display: grid; gap: 14px; min-width: 0; }
.tutorial-tabs {
  justify-self: start; display: inline-flex; flex-wrap: wrap; gap: 4px; padding: 4px;
  border: 1px solid var(--line-strong); border-radius: 999px;
}
.tutorial-tabs [role="tab"] {
  min-height: 44px; padding: 0 18px; border-radius: 999px; border: 1px solid transparent; background: transparent;
  color: var(--muted); font: inherit; font-size: 15px; font-weight: 500; cursor: pointer;
  transition: color 180ms ease, border-color 180ms ease, background-color 180ms ease;
}
.tutorial-tabs [role="tab"]:hover { color: var(--text); }
.tutorial-tabs [role="tab"]:focus-visible { border-radius: 999px; }
.tutorial-tabs [role="tab"][aria-selected="true"] {
  color: var(--text); font-weight: 600; border-color: rgba(82, 218, 229, 0.5); background: rgba(82, 218, 229, 0.14);
}
.tutorial-note { color: var(--muted-soft); font-size: 14px; line-height: 1.6; text-wrap: pretty; }
.tutorial-note:empty { display: none; }
.tutorial-cta { width: 100%; }
@media (min-width: 480px) { .tutorial-cta { width: auto; justify-self: start; min-width: 220px; } }
/* 七步（2026-10-21 起带图标）：每步一个发光圆形图标 + 右下角序号。
   手机与平板是竖向时间线（图标之间一条竖线）；桌面横排一行七个，图标之间一条横线，放在视频上方。 */
.tutorial-steps { list-style: none; margin: 0; padding: 0; display: grid; }
.tutorial-step { position: relative; display: grid; grid-template-columns: 52px 1fr; column-gap: 16px; align-items: start; padding-bottom: 20px; }
.tutorial-step:last-child { padding-bottom: 0; }
/* 竖线：从这一步图标底部连到下一步图标顶部 */
.tutorial-step:not(:last-child)::before {
  content: ""; position: absolute; left: 23px; top: 50px; bottom: 2px; width: 2px; border-radius: 2px;
  background: linear-gradient(180deg, rgba(123, 92, 255, 0.7), rgba(82, 218, 229, 0.35));
}
.tutorial-mark { position: relative; width: 48px; height: 48px; }
.tutorial-icon {
  width: 48px; height: 48px; border-radius: 50%; display: grid; place-items: center; color: #fff;
  background: radial-gradient(circle at 30% 25%, #8FE9F2, #4F7DFF 55%, #6A4BFF);
  box-shadow: 0 0 18px rgba(91, 120, 255, 0.55), inset 0 1px 0 rgba(255, 255, 255, 0.35);
}
.tutorial-icon svg { width: 22px; height: 22px; }
.tutorial-index {
  display: grid; place-items: center; width: 48px; height: 48px; border-radius: 50%;
  color: #DCE4FF; font-family: var(--font-display); font-weight: 600; font-size: 18px; line-height: 1;
  font-variant-numeric: tabular-nums; border: 1px solid rgba(143, 168, 255, 0.6);
}
/* 有图标时序号缩成右下角的小圆标 */
.tutorial-icon + .tutorial-index {
  position: absolute; right: -6px; bottom: -6px; width: 24px; height: 24px; border: 0; font-size: 14px;
  color: #fff; background: #0B1A3A; box-shadow: 0 0 0 2px rgba(123, 92, 255, 0.9);
}
.tutorial-body { min-width: 0; padding-top: 2px; }
.tutorial-body h3 { font-size: 17px; line-height: 1.4; }
.tutorial-body p { color: var(--muted-soft); font-size: 15px; line-height: 1.65; margin-top: 4px; text-wrap: pretty; }
@media (min-width: 768px) {
  .section-tutorial { padding-bottom: 24px; }
  .tutorial-layout { gap: 40px; margin-top: 36px; }
  .tutorial-note { font-size: 15px; }
  .tutorial-body h3 { font-size: 18px; }
}
@media (min-width: 1024px) {
  .tutorial-layout { gap: 44px; margin-top: 44px; }
  .tutorial-steps { order: -1; grid-template-columns: repeat(7, minmax(0, 1fr)); column-gap: 14px; }
  .tutorial-step { grid-template-columns: 1fr; justify-items: center; align-content: start; text-align: center; row-gap: 14px; padding-bottom: 0; }
  /* 横线：从上一步图标右边连到这一步图标左边（left/right 的百分比按本列宽算，列间距 14px） */
  .tutorial-step:not(:last-child)::before { display: none; }
  .tutorial-step + .tutorial-step::after {
    content: ""; position: absolute; top: 31px; height: 2px; border-radius: 2px;
    left: calc(-50% - 14px + 42px); right: calc(50% + 42px);
    background: linear-gradient(90deg, rgba(123, 92, 255, 0.8), rgba(82, 218, 229, 0.6));
  }
  .tutorial-mark, .tutorial-icon, .tutorial-index { width: 64px; height: 64px; }
  .tutorial-icon svg { width: 28px; height: 28px; }
  .tutorial-icon + .tutorial-index { width: 26px; height: 26px; right: -4px; bottom: -4px; }
  .tutorial-body { padding-top: 0; }
  .tutorial-body h3 { font-size: 16px; }
  .tutorial-body p { font-size: 14px; line-height: 1.6; }
  .tutorial-player { width: 100%; max-width: 880px; justify-self: center; }
  .tutorial-cta { justify-self: center; }
}

/* ---------- 产品理念与发展方向：蓝青渐变横幅 ---------- */
.section-vision { padding-block: 0; }
.vision-band {
  position: relative; overflow: hidden; border-radius: var(--radius);
  padding: 36px 24px;
  background: linear-gradient(135deg, #1A46B8 0%, #1B58A4 45%, #0F3F6B 100%);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.14), 0 30px 60px -40px rgba(31, 86, 216, 0.6);
  display: grid; gap: 28px;
}
.vision-label { color: rgba(243, 247, 253, 0.84); font-size: 14px; font-weight: 500; letter-spacing: 0.02em; margin-bottom: 12px; }
.vision-label:empty { display: none; }
.vision-statement { font-size: clamp(28px, 7vw, 34px); line-height: 1.25; letter-spacing: -0.01em; color: #FFFFFF; text-wrap: balance; }
.vision-points { display: grid; gap: 22px; }
.vision-point h3 { font-size: 17px; color: #FFFFFF; }
.vision-point p { color: rgba(243, 247, 253, 0.84); font-size: 15px; line-height: 1.7; margin-top: 6px; max-width: 26em; }
.vision-mark {
  position: absolute; right: -4%; bottom: -18%; width: 46%; aspect-ratio: 1200 / 700; pointer-events: none;
  background: url("assets/brand/ms-glyph.png") center / contain no-repeat; opacity: 0.07;
}
/* 右上角青光是独立一层，20 秒漂移一次；全站唯一的环境动效 */
.vision-band::before {
  content: ""; position: absolute; inset: -30% -20%; pointer-events: none;
  background: radial-gradient(ellipse 34% 40% at 78% 22%, rgba(82, 218, 229, 0.26), transparent 70%);
}
@media (prefers-reduced-motion: no-preference) {
  .vision-band::before { animation: band-light 20s ease-in-out infinite alternate; }
  @keyframes band-light { from { transform: translate(0, 0); } to { transform: translate(-6%, 8%); } }
}
.vision-band > * { position: relative; }
.vision-band > .vision-mark { position: absolute; }
@media (max-width: 767px) { .vision-mark { width: 56%; right: -14%; bottom: -34%; opacity: 0.06; } }
@media (min-width: 768px) {
  .vision-band { padding: 48px 40px; }
  .vision-statement { font-size: 38px; }
  .vision-point h3 { font-size: 18px; }
  .vision-point p { font-size: 16px; }
}
@media (min-width: 1024px) {
  .vision-band { grid-template-columns: 5fr 7fr; gap: 64px; align-items: center; padding: 64px 64px; }
  .vision-statement { font-size: 44px; }
  .vision-points { gap: 28px; }
}

/* ---------- 获取妙算 AI：居中卡片 ---------- */
.section-download { padding-top: 72px; position: relative; overflow: hidden; }
.section-download::before {
  content: ""; position: absolute; left: 50%; top: 30%; width: min(900px, 120vw); height: 90%; transform: translateX(-50%);
  background: radial-gradient(ellipse 50% 50% at 50% 50%, rgba(82, 218, 229, 0.085), transparent 70%);
  pointer-events: none; z-index: 0;
}
.section-download > .container { position: relative; z-index: 1; }
@media (min-width: 768px) { .section-download { padding-top: 96px; } }
.download-card {
  margin-top: 20px;
  background: linear-gradient(180deg, #13304F, #102842);
  border: 1px solid rgba(82, 218, 229, 0.18); border-radius: var(--radius);
  padding: 24px 20px; min-width: 0;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.10), 0 40px 80px -48px rgba(57, 120, 246, 0.55);
}
@media (min-width: 768px) { .download-card { padding: 32px 36px; margin-top: 24px; } }

.download-card-head { display: flex; gap: 18px; align-items: center; }
.download-icon { width: 48px; height: 48px; flex: none; display: block; }
.download-product { font-family: var(--font-display); font-weight: 600; font-size: 20px; line-height: 1.3; }
.download-state { color: var(--accent); font-size: 14px; font-weight: 500; margin-top: 6px; }
.download-state:empty { display: none; }
.dl-action { margin-top: 20px; }
.dl-action .btn { width: 100%; }
.dl-explain { color: var(--muted); font-size: 15px; line-height: 1.8; max-width: 34em; }
.dl-explain + .btn, .dl-explain + .dl-choice-list { margin-top: 16px; }
.dl-address {
  display: block; margin-top: 12px; padding: 12px 14px; border-radius: 10px;
  background: rgba(8, 21, 37, 0.6); border: 1px solid var(--line);
  font-size: 14px; color: var(--muted); overflow-wrap: anywhere; word-break: break-all; user-select: all;
}
.dl-choice-list { display: grid; gap: 10px; }
.dl-choice-list .btn { justify-content: flex-start; text-align: left; flex-wrap: wrap; }
.dl-choice-list .btn small { color: var(--muted); font-weight: 400; font-size: 14px; margin-left: 8px; }
.dl-support-link { margin-top: 12px; font-size: 15px; }
[data-download-state="supported-desktop"] .dl-action,
[data-download-state="mobile-available"] .dl-action,
[data-download-state="mobile-unavailable"] .dl-action,
[data-download-state="in-app-browser"] .dl-action,
[data-download-state="unknown-device"] .dl-action { margin-top: 22px; padding-top: 22px; border-top: 1px solid var(--line); }
.dl-status { margin-top: 12px; color: var(--accent); font-size: 15px; }
.dl-status:empty { display: none; }
.dl-status[data-tone="error"] { color: #FFB4A8; }
.copy-fallback { margin-top: 12px; }
.copy-fallback label { display: block; font-size: 14px; color: var(--muted); margin-bottom: 6px; }
.copy-fallback textarea {
  width: 100%; font: inherit; font-size: 14px; padding: 10px 12px; color: var(--text);
  background: rgba(8, 21, 37, 0.6); border: 1px solid var(--line-strong); border-radius: 10px; resize: vertical; overflow-wrap: anywhere;
}
.dl-alternatives { margin-top: 16px; border-top: 1px solid var(--line); padding-top: 8px; }
.dl-alternatives summary { cursor: pointer; color: var(--muted); padding: 8px 0; min-height: 44px; display: flex; align-items: center; font-size: 15px; }
.dl-alternatives summary:hover { color: var(--text); }
.dl-alternatives ul { display: grid; gap: 8px; margin-top: 6px; }
.dl-alternatives li a {
  display: flex; flex-wrap: wrap; gap: 4px 12px; align-items: baseline;
  padding: 10px 12px; min-height: 44px; border-radius: 10px; border: 1px solid var(--line);
  color: var(--text); text-decoration: none; transition: border-color 180ms ease;
}
.dl-alternatives li a:hover { border-color: var(--accent); }
.dl-alternatives li a small { color: var(--muted); font-size: 14px; }
.release-meta { margin: 20px 0 0; border-top: 1px solid var(--line); }
.release-meta > div { display: grid; gap: 4px; padding: 10px 0; border-bottom: 1px solid var(--line); }
.release-meta dt { color: var(--muted); font-size: 14px; }
.release-meta dd { margin: 0; overflow-wrap: anywhere; font-variant-numeric: tabular-nums; }
@media (min-width: 480px) { .release-meta > div { grid-template-columns: 9em 1fr; align-items: baseline; } }
.tag-list { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.tag-list li { padding: 6px 12px; border-radius: 999px; border: 1px solid var(--line-strong); font-size: 14px; overflow-wrap: anywhere; }
.install-steps { margin-top: 24px; }
.install-steps h3 { font-size: 16px; margin-bottom: 10px; }
.install-steps ol { padding-left: 1.4em; display: grid; gap: 6px; font-size: 15px; }
.note { color: var(--muted); font-size: 14px; margin-top: 10px; }
.first-product { color: var(--muted); font-size: 14px; margin-top: 20px; padding-top: 16px; border-top: 1px solid transparent; border-image: var(--hairline); }
.first-product:empty { display: none; }

/* ---------- 常见问题：窄栏 ---------- */
.section-faq { padding-top: 24px; }
.faq-list { margin-top: 28px; border-top: 1px solid transparent; border-image: var(--hairline); }
.faq-item { border-bottom: 1px solid transparent; border-image: var(--hairline); }
.faq-item summary {
  list-style: none; cursor: pointer; display: flex; justify-content: space-between; gap: 16px;
  align-items: center; padding: 18px 0; min-height: 60px; font-weight: 500; font-size: 17px;
  transition: color 180ms ease;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+"; content: "+" / ""; flex: none; width: 24px; text-align: center; font-size: 24px; line-height: 1; font-weight: 300; color: var(--muted);
  transition: color 180ms ease, transform 220ms cubic-bezier(0.2, 0.7, 0.2, 1);
}
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item summary:hover, .faq-item summary:hover::after { color: var(--accent); }
.faq-body { padding: 0 0 20px; color: var(--muted-soft); font-size: 15px; line-height: 1.85; max-width: 40em; }
.faq-item[open] .faq-body { animation: faq-in 220ms ease both; }
@keyframes faq-in { from { opacity: 0; transform: translateY(-4px); } to { opacity: 1; transform: none; } }
.faq-body ul { margin-top: 8px; padding-left: 1.3em; display: grid; gap: 4px; }
@media (min-width: 768px) { .faq-body { font-size: 16px; } }

/* ---------- 页脚 ---------- */
.site-footer {
  margin-top: 24px;
  background: linear-gradient(90deg, transparent, rgba(182, 199, 219, 0.3) 30%, rgba(182, 199, 219, 0.3) 70%, transparent) top / 100% 1px no-repeat;
  padding-block: 40px calc(40px + env(safe-area-inset-bottom));
  color: var(--muted); font-size: 14px;
}
.footer-inner { display: grid; gap: 24px; }
.footer-name { color: var(--text); font-weight: 600; font-size: 18px; letter-spacing: 0.02em; }
.footer-tagline { color: var(--text); margin-top: 6px; font-size: 15px; }
.footer-tagline:empty { display: none; }
.footer-disclaimer { margin-top: 10px; max-width: 30em; }
.footer-heading { font-size: 14px; color: var(--text); font-weight: 600; margin-bottom: 8px; }
.footer-links ul, .footer-contact ul { display: grid; gap: 6px; }
.footer-contact li { overflow-wrap: anywhere; }
.footer-entity { grid-column: 1 / -1; font-size: 14px; border-top: 1px solid transparent; border-image: var(--hairline); padding-top: 16px; }
@media (min-width: 768px) { .footer-inner { grid-template-columns: 2fr 1fr 1fr; gap: 32px; } }

/* ---------- 静态信息页 ---------- */
/* ---------- 404：复用首屏排版，撑满首屏高度 ---------- */
.error-page { min-height: calc(100vh - var(--header-h) - 120px); display: flex; align-items: center; padding-block: 56px 72px; }
.error-page .container-hero { animation: none; }
.error-page .eyebrow { letter-spacing: 0.12em; }
.error-page h1 { display: block; font-size: clamp(34px, 5.4vw, 64px); line-height: 1.12; }
@media (min-width: 768px) { .error-page { padding-block: 72px 96px; } }

.static-page { padding-block: 40px 72px; }
.static-page h1 { font-size: clamp(28px, 5vw, 36px); letter-spacing: -0.01em; }
.static-page .updated { color: var(--muted); margin-top: 10px; font-size: 14px; }
.static-page article { margin-top: 28px; max-width: 42em; color: var(--muted); line-height: 1.85; }
/* 正文整块用系统字体，h2/h3 要单独点名——它们的 font-family 来自全局的 h1,h2,h3 规则，不继承 article。
   与 tools/build_fonts.py 的 ARTICLE_SYSTEM_FONT 成对：那边把这些页的 <article> 排除出子集，
   这里少了这条规则，正文就会逐字符回退成混排。tests/legal-page.test.mjs 守着这对关系。 */
.static-page article, .static-page article h2, .static-page article h3 { font-family: var(--font-system); }
.static-page article .policy-intro { color: var(--text); font-size: 17px; line-height: 1.8; padding-bottom: 20px; border-bottom: 1px solid transparent; border-image: var(--hairline); }
.static-page article h2 { font-size: 20px; margin-top: 36px; color: var(--text); }
.static-page article h3 { font-size: 16px; margin-top: 18px; color: var(--text); font-weight: 600; }
.static-page article p { margin-top: 10px; }
.static-page article ul { margin: 8px 0 0; padding-left: 1.3em; display: grid; gap: 4px; }
.static-page article a { color: var(--accent); }
.static-page .back { display: inline-flex; margin-top: 36px; }
/* 开源许可页（app-licenses.html）：库坐标与许可证全文。全文放在可展开的 details 里，默认折叠；
   pre 用系统字体并自动换行，不进子集字体（整页 <article> 在 ARTICLE_SYSTEM_FONT 里）。 */
.static-page article code { font-size: 0.95em; word-break: break-all; } /* 不换字体：守护不许 article 里出现别的 font-family */
.static-page article .license-text { margin-top: 14px; border-bottom: 1px solid transparent; border-image: var(--hairline); }
.static-page article .license-text summary { cursor: pointer; color: var(--text); font-weight: 600; padding: 10px 0; list-style: none; }
.static-page article .license-text summary::-webkit-details-marker { display: none; }
.static-page article .license-text summary:hover { color: var(--accent); }
.static-page article .license-text pre { white-space: pre-wrap; word-break: break-word; font-family: var(--font-system); font-size: 14px; line-height: 1.7; margin: 0 0 16px; color: var(--muted); }
/* App 内模式：下载器内置浏览器带 ?app=1 打开时，app-mode.js 在首帧之前给 <html> 加 .app-mode（页面清单见
   tests/app-mode-pages.mjs）。只藏官网自己的页头与「返回首页」——App 有自己的顶栏，在 App 里也不必再引导
   「获取 APP」；配色不变（需求方 2026-10-05 定）。页头是 sticky，藏掉后正文上方不留白，只有锚点跳转的预留量要缩。 */
html.app-mode .site-header,
html.app-mode .back { display: none; }
html.app-mode { scroll-padding-top: 12px; }
@media (min-width: 768px) { .static-page { padding-block: 56px 96px; } .static-page article h2 { font-size: 22px; } }

/* 新手指引页（/guide/<平台代号>/，2026-09-29 起；2026-10-16 起三页都是 v2，结构见 guide/wlsc/index.html）：
   只凭链接打开、主要在手机上看。上方一段教学视频、一排章节跳转，下面按章（h2）分组、一步一节（h3 标题 → 图 → 说明与提示）。
   这页不进 tools/build_fonts.py 的 TEXT_SOURCES——全站子集因此一个字都不变——所以 <main> 里的字一律用系统字体：
   <article> 与其中的 h2、h3 由上面 .static-page article 那条规则管，h1 在这里单独点名（它的字体来自全局 h1,h2,h3 规则）。
   这条不能包进 @media，tests/guide-page.test.mjs 守着。下面每条都以 .guide-page 开头，只作用于指引页。 */
.guide-page h1 { font-family: var(--font-system); }
.guide-page article { max-width: none; margin-top: 16px; }
.guide-page .guide-tip, .guide-page .guide-hint { color: var(--muted-soft); font-size: 15px; }
/* 窄屏只在两句之间换行，不让最后一两个字单独掉到下一行 */
.guide-page .guide-keep { display: inline-block; }
.guide-page .guide-video { margin-top: 16px; border: 1px solid var(--line); border-radius: 12px; overflow: hidden; background: var(--surface); }
/* 先按 16:9 占位：封面图下来之前不塌成浏览器默认的 300×150 */
.guide-page .guide-video video { display: block; width: 100%; height: auto; aspect-ratio: 16 / 9; }
.guide-page .guide-note { margin-top: 8px; color: var(--muted-soft); font-size: 14px; }
/* 间距一律用外边距、不用 gap：下载器最低支持 Android 5.1，老 WebView（84 以前）不认 flex 的 gap，
   用了的话跳转按钮会贴在一起、「下载安装第 1–10 步」连成一串。按钮高 44px，够手指点（README 的触控目标下限）。 */
.guide-page .guide-toc { display: flex; flex-wrap: wrap; margin-top: 12px; }
.guide-page .guide-toc a { display: inline-flex; align-items: center; min-height: 44px; margin: 8px 8px 0 0; padding: 0 16px; border: 1px solid var(--line-strong); border-radius: 999px; color: var(--text); font-size: 14px; text-decoration: none; }
.guide-page .guide-toc a:hover { border-color: var(--accent); color: var(--accent); }
.guide-page .guide-toc + .guide-tip { margin-top: 16px; }
.guide-page .guide-chapter { margin-top: 48px; }
.guide-page .guide-chapter > h2 { margin-top: 0; padding-bottom: 10px; border-bottom: 1px solid transparent; border-image: var(--hairline); }
.guide-page .guide-range { display: inline-block; margin-left: 12px; color: var(--muted-soft); font-size: 14px; font-weight: 400; }
.guide-page .guide-step { margin-top: 32px; }
/* 「个人中心」「设置」这类以全角引号开头的标题，引号自带的左半格空白会让它离序号比别的节远；支持的浏览器里去掉 */
.guide-page .guide-step h3 { display: flex; align-items: baseline; margin-top: 0; font-size: 17px; line-height: 1.5; text-spacing-trim: trim-start; }
.guide-page .guide-no { color: var(--accent); font-variant-numeric: tabular-nums; }
.guide-page .guide-step h3 .guide-no { flex: none; margin-right: 10px; }
.guide-page .guide-shot { display: block; margin-top: 12px; border: 1px solid var(--line); border-radius: 12px; overflow: hidden; background: var(--surface); }
.guide-page .guide-shot img { width: 100%; }
@media (min-width: 768px) { .guide-page .guide-chapter { margin-top: 64px; } .guide-page .guide-step { margin-top: 44px; } .guide-page .guide-step h3 { font-size: 18px; } }
/* 「点视频就横屏铺满」（guide-video.js，2026-10-23 起，只在触屏设备上装；10-26 用户选方案 2，去掉了视频下面的
   「全屏横着看」按钮）：下载器的内置浏览器禁了网页请求横屏，开着方向锁定时屏幕不转，所以把视频画面转 90° 铺满屏幕（伪横屏）。
   在页面里时视频不带控件，画面上盖一层「横屏播放」（.guide-video-play，整块画面都能点；圆形 ▶ 与「横屏播放」并排放在底部正中，
   不放正中——封面正中是片头的产品名，放正中会压住它）；点了进全屏、控件回来、开始播放，
   这时盖的那层藏起来。盖的那层、舞台、× 都是脚本造的，脚本没跑时页面照旧。
   全屏的是 .guide-video 容器；转的是里面那层 .guide-video-stage——浏览器给全屏元素本身写死了 transform: none !important。
   竖屏时舞台宽 100vh、高 100vw、顺时针转 90°（手机逆时针横过来看就是正的，× 落在横拿时的右上角）；横屏时不转、直接铺满。
   要不到全屏时（is-fallback）容器 position: fixed 盖满页面，页面本身不让滚。字一律系统字体（指引页 <main> 不进子集）。
   行为由 tests/guide-fullscreen-check.mjs 在真浏览器里查。 */
.guide-page .guide-video-stage { position: relative; }
.guide-page .guide-video-play { position: absolute; top: 0; right: 0; bottom: 0; left: 0; display: flex; flex-direction: row; align-items: flex-end; justify-content: center; width: 100%; height: 100%; margin: 0; padding: 0 0 12px; border: 0; border-radius: 0; background: linear-gradient(180deg, rgba(8, 21, 37, 0) 45%, rgba(8, 21, 37, 0.6)); color: #fff; font-family: var(--font-system); font-size: 15px; cursor: pointer; -webkit-tap-highlight-color: transparent; }
.guide-page .guide-video-play-icon { position: relative; flex: none; box-sizing: border-box; width: 44px; height: 44px; border: 2px solid var(--accent); border-radius: 50%; background: rgba(8, 21, 37, 0.78); box-shadow: 0 4px 14px rgba(0, 0, 0, 0.45); }
/* ▶：边框画的三角，往右挪一点，看起来才在圆心 */
.guide-page .guide-video-play-icon::after { content: ""; position: absolute; top: 50%; left: 50%; width: 0; height: 0; margin: -9px 0 0 -5px; border-top: 9px solid transparent; border-bottom: 9px solid transparent; border-left: 15px solid #fff; }
/* 「横屏播放」与 ▶ 等高并排（44px，底边对齐即中线对齐），带一块深色底：底部压着片头的图例小字，不垫底就叠在一起看不清 */
.guide-page .guide-video-play-text { box-sizing: border-box; height: 44px; margin-left: 8px; padding: 0 16px; border-radius: 999px; background: rgba(8, 21, 37, 0.78); font-family: var(--font-system); font-size: 15px; line-height: 44px; white-space: nowrap; }
.guide-page .guide-video.is-fullscreen .guide-video-play { display: none; }
/* × 藏着时也写上字体与字号：部署后的 legal-pages-check 连藏着的元素也量，按钮默认 13.33px 会被判不够 14px */
.guide-page .guide-video-close { display: none; font-family: var(--font-system); font-size: 26px; line-height: 1; }
.guide-page .guide-video.is-fullscreen { position: fixed; top: 0; right: 0; bottom: 0; left: 0; z-index: 1000; margin: 0; border: 0; border-radius: 0; background: #000; }
.guide-page .guide-video.is-fullscreen .guide-video-stage { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }
.guide-page .guide-video.is-fullscreen video { width: 100%; height: 100%; aspect-ratio: auto; object-fit: contain; background: #000; }
.guide-page .guide-video.is-fullscreen .guide-video-close { display: flex; align-items: center; justify-content: center; position: absolute; top: 12px; right: 12px; width: 44px; height: 44px; padding: 0; border: 1px solid rgba(255, 255, 255, 0.35); border-radius: 50%; background: rgba(8, 21, 37, 0.72); color: #fff; cursor: pointer; }
@media (orientation: portrait) {
  .guide-page .guide-video.is-fullscreen .guide-video-stage { top: 50%; left: 50%; width: 100vh; height: 100vw; transform: translate(-50%, -50%) rotate(90deg); }
}
html.guide-video-open, html.guide-video-open body { overflow: hidden; }

/* ---------- 交流群卡片（brand.community + brand.contact 里的 QQ 群）----------
   放在「获取妙算 AI」之后、FAQ 之前：手机下载卡录进了指引视频，这块在它下面，不进画面。 */
.section-community { padding-block: 8px 40px; }
.community-card {
  position: relative; overflow: hidden; border-radius: var(--radius); padding: 24px 20px;
  display: grid; gap: 18px; align-items: center;
  border: 1px solid var(--neon-edge);
  background:
    radial-gradient(ellipse 50% 120% at 0% 50%, rgba(123, 92, 255, 0.28), transparent 65%),
    radial-gradient(ellipse 50% 120% at 100% 50%, rgba(57, 120, 246, 0.24), transparent 65%),
    linear-gradient(180deg, rgba(18, 34, 78, 0.95), rgba(12, 26, 58, 0.85));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08), var(--neon-glow);
}
.community-icon {
  width: 56px; height: 56px; border-radius: 16px; display: grid; place-items: center; color: #fff;
  background: radial-gradient(circle at 30% 25%, #8FE9F2, #4F7DFF 55%, #6A4BFF);
  box-shadow: 0 0 22px rgba(91, 120, 255, 0.6), inset 0 1px 0 rgba(255, 255, 255, 0.35);
}
.community-title { font-size: 22px; line-height: 1.35; }
.community-text { color: var(--muted); font-size: 15px; line-height: 1.65; margin-top: 6px; text-wrap: pretty; }
.community-action { display: grid; gap: 10px; }
.community-number { display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; }
.community-number-label { color: var(--muted-soft); font-size: 14px; }
.community-number-value {
  font-family: var(--font-display); font-weight: 600; font-size: 26px; letter-spacing: 0.04em; font-variant-numeric: tabular-nums;
  background: linear-gradient(90deg, #F3F7FD, #BFEFF5 60%, #52DAE5); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.btn-primary.community-copy {
  background: linear-gradient(90deg, var(--violet), #3978F6); color: #fff; border-color: rgba(255, 255, 255, 0.18);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.25), 0 0 24px rgba(123, 92, 255, 0.55);
}
.btn-primary.community-copy:hover { background: linear-gradient(90deg, #8D72FF, #4A88FF); color: #fff; }
.community-status { color: var(--accent); font-size: 14px; line-height: 1.5; min-height: 1.5em; }
@media (min-width: 768px) {
  .section-community { padding-block: 24px 64px; }
  .community-card { grid-template-columns: auto 1fr auto; gap: 28px; padding: 28px 36px; }
  .community-action { justify-items: end; text-align: right; }
  .community-number { justify-content: flex-end; }
  .community-status { min-height: 0; }
}

/* ---------- 霓虹光效（2026-10-21）----------
   用户对照需求方样图：「是不是只有背景差了点？」——补紫蓝大光晕与霓虹描边，只动背景与边框，不动文字与布局。
   红线：手机首屏（含首屏下方露出的「认识妙算」标题与介绍）与手机下载卡录进了新手指引视频，
   所以 .hero、.section-about 的背景与下载区只在 ≥1024px 加光；数字栏、视频框、教学区、横幅不在录屏里，各宽度都加。 */
.stats {
  border-color: var(--neon-edge);
  background:
    radial-gradient(ellipse 60% 120% at 0% 0%, rgba(123, 92, 255, 0.22), transparent 60%),
    radial-gradient(ellipse 60% 120% at 100% 100%, rgba(57, 120, 246, 0.25), transparent 60%),
    linear-gradient(180deg, rgba(18, 34, 78, 0.92), rgba(12, 26, 58, 0.78));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08), var(--neon-glow);
}
/* 手机上数字栏紧挨着录屏里拍到的介绍段：光只往下散，不往上漫进那段 */
@media (max-width: 1023px) {
  .about-stats { box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08), 0 0 0 1px rgba(82, 218, 229, 0.18), 0 26px 40px -22px rgba(123, 92, 255, 0.6); }
}
.stat-icon { background: radial-gradient(circle at 30% 25%, #8FE9F2, #4F7DFF 55%, #6A4BFF); box-shadow: 0 0 20px rgba(91, 120, 255, 0.65), inset 0 1px 0 rgba(255, 255, 255, 0.35); }
.video-frame { border-color: var(--neon-edge); box-shadow: var(--neon-glow); }
.section-tutorial { position: relative; }
.section-tutorial::before {
  content: ""; position: absolute; inset: 0; pointer-events: none; z-index: 0;
  background:
    radial-gradient(ellipse 55% 45% at 15% 35%, rgba(123, 92, 255, 0.16), transparent 70%),
    radial-gradient(ellipse 50% 40% at 90% 60%, rgba(57, 120, 246, 0.14), transparent 70%);
}
.section-tutorial > .container { position: relative; z-index: 1; }
.tutorial-tabs { border-color: var(--neon-edge); }
.tutorial-tabs [role="tab"][aria-selected="true"] {
  border-color: transparent; color: #fff;
  background: linear-gradient(90deg, var(--violet), #3978F6); box-shadow: 0 0 18px rgba(123, 92, 255, 0.55);
}
.btn-primary.tutorial-cta {
  background: linear-gradient(90deg, var(--violet), #3978F6); color: #fff; border-color: rgba(255, 255, 255, 0.18);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.25), 0 0 24px rgba(123, 92, 255, 0.55);
}
.btn-primary.tutorial-cta:hover { background: linear-gradient(90deg, #8D72FF, #4A88FF); color: #fff; box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.3), 0 0 36px rgba(123, 92, 255, 0.75); }
.vision-band {
  background:
    radial-gradient(ellipse 60% 90% at 100% 0%, rgba(123, 92, 255, 0.55), transparent 60%),
    linear-gradient(135deg, #1A46B8 0%, #1B58A4 45%, #0F3F6B 100%);
  border: 1px solid var(--neon-edge);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.16), var(--neon-glow);
}
@media (min-width: 1024px) {
  .hero::before {
    inset: -80px 0 0 0;
    background:
      radial-gradient(ellipse 45% 60% at 78% 38%, rgba(123, 92, 255, 0.5), transparent 70%),
      radial-gradient(ellipse 50% 55% at 15% 10%, rgba(57, 120, 246, 0.5), transparent 70%),
      radial-gradient(ellipse 40% 40% at 60% 90%, rgba(82, 218, 229, 0.16), transparent 72%),
      linear-gradient(180deg, rgba(24, 34, 96, 0.9) 0%, rgba(8, 21, 37, 0) 100%);
    /* 底部渐隐，不在数字栏下方留一道硬边 */
    -webkit-mask-image: linear-gradient(180deg, #000 72%, transparent 100%);
    mask-image: linear-gradient(180deg, #000 72%, transparent 100%);
  }
  .hero-visual::before {
    content: ""; position: absolute; inset: -18% -10% -22% -12%; z-index: -1; pointer-events: none;
    background: radial-gradient(closest-side, rgba(110, 90, 255, 0.55), rgba(57, 120, 246, 0.25) 55%, transparent);
    filter: blur(20px);
  }
  .hero-screen {
    border: 1.5px solid rgba(140, 190, 255, 0.85);
    box-shadow:
      0 0 0 1px rgba(82, 218, 229, 0.35), 0 0 22px rgba(82, 218, 229, 0.55), 0 0 60px rgba(123, 92, 255, 0.6),
      0 40px 90px -30px rgba(57, 120, 246, 0.8);
  }
  .hero .h1-brand {
    background: linear-gradient(90deg, #C3B2FF 0%, #8FB0FF 50%, #7FE6F0 100%);
    -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
    filter: drop-shadow(0 0 24px rgba(123, 92, 255, 0.45));
  }
  .hero .btn-primary {
    background: linear-gradient(90deg, var(--violet), #3978F6); color: #fff; border-color: rgba(255, 255, 255, 0.18);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.25), 0 0 28px rgba(123, 92, 255, 0.6);
  }
  .hero .btn-primary:hover { background: linear-gradient(90deg, #8D72FF, #4A88FF); color: #fff; box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.3), 0 0 40px rgba(123, 92, 255, 0.8); }
  .section-about::before {
    background:
      radial-gradient(ellipse 45% 40% at 85% 30%, rgba(123, 92, 255, 0.16), transparent 70%),
      radial-gradient(ellipse 60% 42% at 30% 60%, rgba(57, 120, 246, 0.16), transparent 70%);
  }
  .section-download::before {
    background:
      radial-gradient(ellipse 50% 50% at 50% 50%, rgba(123, 92, 255, 0.2), transparent 70%),
      radial-gradient(ellipse 35% 35% at 50% 45%, rgba(82, 218, 229, 0.1), transparent 70%);
  }
  .download-card { border-color: var(--neon-edge); box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.10), var(--neon-glow); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; animation: none !important; }
}