/* =================================================================
 * 通用型数据处理系统 · 官网前台样式
 * 设计原则：科技感 + 玻璃态 + 响应式 + 动效流畅
 * ================================================================= */

* { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg-deep:   #050a1a;
  --bg-mid:    #0a1535;
  --bg-glow:   #1e3a8a;
  --accent:    #3b82f6;
  --accent-2:  #06b6d4;
  --accent-3:  #8b5cf6;
  --text:      #f1f5f9;
  --text-mute: #94a3b8;
  --text-dim:  #64748b;
  --shadow-1:  0 10px 30px rgba(0, 0, 0, 0.45);
  --shadow-2:  0 24px 60px rgba(0, 0, 0, 0.55);
  --radius:    16px;
  --radius-l:  28px;
  --t-fast:    240ms cubic-bezier(.22,1,.36,1);
  --t-mid:     480ms cubic-bezier(.22,1,.36,1);
  --t-slow:    900ms cubic-bezier(.22,1,.36,1);

  /* 由 JS 注入的背景变量 */
  --bg-c1: var(--bg-deep);
  --bg-c2: var(--bg-glow);
  --bg-angle: 135deg;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;            /* 整页滚动由 JS 控制 */
  overscroll-behavior: none;   /* 禁止滚动回弹（微信等浏览器下拉干扰） */
  background: var(--bg-deep);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei',
               'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
}

body {
  user-select: none;
}

img, video {
  max-width: 100%;
  display: block;
}

button {
  font: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

a {
  color: inherit;
  text-decoration: none;
}

/* =================================================================
 * 加载层
 * ================================================================= */
.loader {
  position: fixed; inset: 0;
  background: var(--bg-deep);
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  gap: 18px;
  z-index: 9999;
  transition: opacity 600ms ease;
}
.loader.hidden {
  display: none;
}
.loader-spinner {
  width: 48px; height: 48px;
  border: 3px solid rgba(255,255,255,0.12);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 900ms linear infinite;
}
.loader-text {
  color: var(--text-mute);
  font-size: 14px;
  letter-spacing: 2px;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* =================================================================
 * 整体 App（整页滚动容器）
 * ================================================================= */
.app {
  position: fixed;
  inset: 0;
  overflow: hidden;
}

/* =================================================================
 * 单页（全屏）
 * ================================================================= */
.page {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  opacity: 0;
  transform: translateY(40px);
  pointer-events: none;
  transition: opacity var(--t-slow), transform var(--t-slow);
}
.page.is-active {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.page.is-prev {
  opacity: 0;
  transform: translateY(-40px);
}
.page.is-next {
  opacity: 0;
  transform: translateY(40px);
}

/* =================================================================
 * 背景
 * ================================================================= */
.bg-layer {
  position: absolute;
  inset: 0;
  z-index: -2;
}
.bg-canvas {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  z-index: -1;
  pointer-events: none;
}

/* 教程页：顶部对齐 + 内边距（避免内容超高时居中裁切） */
.page.tut-variant-left,
.page.tut-variant-right,
.page.tut-variant-top,
.page.tut-variant-bottom,
.page.tut-variant-tabs,
.page.tut-variant-grid,
.page.tut-variant-timeline,
.page.tut-variant-mini {
  align-items: start;
  padding: 5vh 4vw;
}

/* 背景类型：tech */
body.bg-tech .bg-layer {
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%,  rgba(59,130,246,.35), transparent 60%),
    radial-gradient(ellipse 60% 60% at 100% 100%, rgba(139,92,246,.25), transparent 60%),
    radial-gradient(ellipse 60% 60% at 0% 100%, rgba(6,182,212,.20), transparent 60%),
    linear-gradient(180deg, var(--bg-deep) 0%, var(--bg-mid) 100%);
}
body.bg-tech .bg-layer::before {
  content: '';
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(148,163,184,.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148,163,184,.06) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 50%, #000 30%, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 50%, #000 30%, transparent 80%);
}

/* 背景类型：gradient */
body.bg-gradient .bg-layer {
  background: linear-gradient(var(--bg-angle),
              var(--bg-c1) 0%, var(--bg-c2) 100%);
}

/* 背景类型：solid */
body.bg-solid .bg-layer {
  background: var(--bg-solid, var(--bg-deep));
}

/* =================================================================
 * 第 1 页：Hero（正式内容：截图 + 文案 + 下载）
 * ================================================================= */
.page-hero {
  text-align: center;
}

.hero-inner {
  position: relative;
  width: min(1100px, 100%);
  /* 不设固定高度，让内容自适应 */
  display: flex; flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: clamp(12px, 2.4vh, 20px);
  padding: 5vh 24px 5vh;
}

/* 软件截图 */
/* 由下至上慢慢升起（用 animation 而非 transition：不依赖"先渲染初始状态"，
   即使 show 类在首帧前添加也保证从下方渐变显现） */
@keyframes heroRise60 {
  from { opacity: 0; transform: translateY(60px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes heroRise46 {
  from { opacity: 0; transform: translateY(46px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes heroRise34 {
  from { opacity: 0; transform: translateY(34px); }
  to   { opacity: 1; transform: translateY(0); }
}
.hero-shot-wrap {
  position: relative;
  max-width: min(580px, 78vw);
  width: fit-content;           /* 容器贴合图片尺寸，不留透明框 */
  border-radius: var(--radius-l);
  overflow: hidden;
  opacity: 0;
  pointer-events: none;
  box-shadow: var(--shadow-2);
  border: 1px solid rgba(255,255,255,.10);
}
.page-hero.show .hero-shot-wrap {
  pointer-events: auto;
  animation: heroRise60 1.4s cubic-bezier(.22,1,.36,1) .05s forwards;
}
.hero-screenshot {
  display: block;
  width: auto; height: auto;    /* 自然比例，浏览器按 max 约束等比缩放 */
  max-width: min(580px, 78vw);
  max-height: 44vh;
  object-fit: contain;
}

/* 截图内的 LOGO 锚点（开场动画 LOGO 的终点位置） */
.shot-anchor {
  position: absolute;
  left: 2.6%;
  top: 3.2%;
  width: 11%;
  aspect-ratio: 1 / 1;
  display: block;
  pointer-events: none;
}

/* 文案：由下至上慢慢升起 */
.hero-text { opacity: 0; }
.page-hero.show .hero-text {
  animation: heroRise46 1.3s cubic-bezier(.22,1,.36,1) .3s forwards;
}

.hero-title {
  font-size: clamp(24px, 3.6vw, 42px);
  font-weight: 700;
  letter-spacing: 1px;
  background: linear-gradient(135deg, #fff 0%, #93c5fd 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: 0 4px 24px rgba(59,130,246,.25);
}
.hero-subtitle {
  font-size: clamp(13px, 1.5vw, 17px);
  color: var(--text-mute);
  margin-top: 6px;
}

/* 下载按钮组：由下至上慢慢升起（最后出现） */
.downloads {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(10px, 1.4vw, 16px);
  width: min(940px, 100%);
  opacity: 0;
}
.page-hero.show .downloads {
  animation: heroRise34 1.2s cubic-bezier(.22,1,.36,1) .55s forwards;
}

.dl-btn {
  position: relative;
  padding: clamp(14px, 2vw, 20px) 16px;
  border-radius: 16px;
  background: linear-gradient(135deg, rgba(59,130,246,.18), rgba(139,92,246,.18));
  border: 1px solid rgba(255,255,255,.10);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex; flex-direction: column;
  align-items: center; gap: 5px;
  color: var(--text);
  transition: transform var(--t-fast), box-shadow var(--t-fast), border-color var(--t-fast), background var(--t-fast);
  overflow: hidden;
  cursor: pointer;
}
.dl-btn::before {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,.16), transparent 60%);
  opacity: 0;
  transition: opacity var(--t-fast);
}
.dl-btn:hover {
  transform: translateY(-4px);
  border-color: rgba(255,255,255,.30);
  box-shadow: 0 18px 40px rgba(59,130,246,.35);
}
.dl-btn:hover::before { opacity: 1; }
.dl-btn:active { transform: translateY(-1px); }
.dl-btn i { font-size: clamp(22px, 2.2vw, 28px); color: #93c5fd; }
.dl-btn .dl-name { font-size: clamp(13px, 1.3vw, 15px); font-weight: 600; }
.dl-btn .dl-meta { font-size: clamp(11px, 1.1vw, 13px); color: var(--text-mute); }
.dl-btn.is-disabled { opacity: .4; cursor: not-allowed; pointer-events: none; }
.dl-btn.is-disabled:hover { transform: none; box-shadow: none; }

/* =================================================================
 * 开场动画层（全新方案：纯 CSS + Canvas 粒子，避开 Three.js）
 * 设计思路：阶段化揭示 + 大量模糊→清晰过渡，比 3D 简单且稳定
 * ================================================================= */
.intro-stage {
  position: absolute;
  inset: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  pointer-events: auto;
  opacity: 1;
  transition: opacity .8s ease;
}
.intro-stage.is-done {
  opacity: 0;
  pointer-events: none;
}

/* ---- 背景光斑（长焦 bokeh） ---- */
.intro-bokeh {
  position: absolute;
  inset: 0;
  pointer-events: none;
}
.bk {
  position: absolute;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(96,165,250,.55), transparent 70%);
  filter: blur(6px);
  opacity: 0;
  animation: bokehFade 9s ease-in-out forwards;
}
.b1 { width: 90px;  height: 90px;  left: 12%; top: 18%; animation-delay: .2s; }
.b2 { width: 60px;  height: 60px;  left: 78%; top: 12%; animation-delay: .6s; background: radial-gradient(circle, rgba(139,92,246,.5), transparent 70%); }
.b3 { width: 130px; height: 130px; left: 85%; top: 55%; animation-delay: 1.1s; background: radial-gradient(circle, rgba(6,182,212,.4), transparent 70%); }
.b4 { width: 70px;  height: 70px;  left: 20%; top: 68%; animation-delay: 1.5s; background: radial-gradient(circle, rgba(59,130,246,.5), transparent 70%); }
.b5 { width: 110px; height: 110px; left: 45%; top: 8%;  animation-delay: .9s;  background: radial-gradient(circle, rgba(139,92,246,.35), transparent 70%); }
.b6 { width: 55px;  height: 55px;  left: 60%; top: 78%; animation-delay: 1.8s; }
.b7 { width: 80px;  height: 80px;  left: 5%;  top: 45%; animation-delay: 2.2s; background: radial-gradient(circle, rgba(6,182,212,.45), transparent 70%); }
.b8 { width: 100px; height: 100px; left: 92%; top: 30%; animation-delay: 2.6s; background: radial-gradient(circle, rgba(96,165,250,.4), transparent 70%); }
.b9 { width: 65px;  height: 65px;  left: 33%; top: 85%; animation-delay: 3s;   background: radial-gradient(circle, rgba(139,92,246,.4), transparent 70%); }
.b10{ width: 140px; height: 140px; left: 68%; top: 40%; animation-delay: 3.4s; background: radial-gradient(circle, rgba(59,130,246,.28), transparent 70%); }
@keyframes bokehFade {
  0%, 15% { opacity: 0; transform: scale(.6); }
  30%, 70% { opacity: .85; transform: scale(1); }
  100% { opacity: .4; transform: scale(1.18); }
}

/* ---- 粒子 canvas ---- */
.intro-particles {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  pointer-events: none;
}

/* ---- 内容容器 ---- */
.intro-content {
  position: relative;
  z-index: 2;
  display: flex; flex-direction: column;
  align-items: center;
  gap: clamp(20px, 4vh, 40px);
  text-align: center;
  padding: 6vh 6vw 10vh;
  width: min(1100px, 100%);
}

/* ---- 阶段 2：大标题（模糊→清晰） ---- */
.intro-title {
  font-size: clamp(40px, 9vw, 110px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: 0.06em;
  display: flex; flex-direction: column;
  align-items: center;
  gap: clamp(4px, 0.8vh, 10px);
  opacity: 0;
  filter: blur(24px);
  transform: translateY(50px) scale(0.94);
  animation: titleReveal 2.2s cubic-bezier(.22,.8,.2,1) 0.7s forwards;
}
.t-line {
  background: linear-gradient(135deg, #ffffff 0%, #c7e0ff 40%, #60a5fa 80%, #93c5fd 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  display: inline-block;
  text-shadow: 0 0 60px rgba(147,197,253,.5);
  opacity: 0;
  transform: translateY(60px);
}
.t-line:nth-child(1) { animation: lineIn 1.2s cubic-bezier(.22,.8,.2,1) 0.8s forwards; }
.t-line:nth-child(2) { animation: lineIn 1.2s cubic-bezier(.22,.8,.2,1) 1.15s forwards; }

/* ---- 阶段 3：副标题 + LOGO 缩略图 ---- */
.intro-sub {
  display: flex; align-items: center; gap: clamp(14px, 1.5vw, 24px);
  opacity: 0;
  transform: translateY(20px);
  animation: subIn 1.4s cubic-bezier(.22,.8,.2,1) 2.4s forwards;
}
.intro-sub-logo {
  width: clamp(54px, 6vw, 72px); height: clamp(54px, 6vw, 72px);
  border-radius: 16px;
  object-fit: contain;
  flex-shrink: 0;
  filter: drop-shadow(0 8px 24px rgba(59,130,246,.4)) drop-shadow(0 0 16px rgba(96,165,250,.3));
  animation: logoBob 4s ease-in-out infinite 3s;
}
@keyframes logoBob {
  0%, 100% { transform: translateY(0) rotate(-2deg); }
  50%      { transform: translateY(-6px) rotate(2deg); }
}
.intro-sub-text {
  font-size: clamp(15px, 1.6vw, 22px);
  color: var(--text-mute);
  font-weight: 500;
  letter-spacing: 1px;
  display: inline-flex; align-items: center;
  flex-wrap: wrap;
}
.intro-sub-text .v { color: #f1f5f9; font-weight: 700; }
.intro-sub-text .g { color: #93c5fd; font-weight: 600; }
.intro-sub-text .dot { margin: 0 8px; color: var(--text-dim); opacity: .6; }

/* ---- 阶段 4：功能卡片网格（5 张，对齐软件界面 5 大模块） ---- */
.intro-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: clamp(8px, 1vw, 14px);
  width: min(1100px, 100%);
}
.ig-card {
  padding: clamp(14px, 1.8vh, 22px) clamp(12px, 1.2vw, 18px);
  border-radius: 16px;
  background: linear-gradient(135deg, rgba(255,255,255,.07), rgba(255,255,255,.02));
  border: 1px solid rgba(255,255,255,.10);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  display: flex; flex-direction: column; gap: 8px;
  align-items: center;
  text-align: center;
  opacity: 0;
  transform: translateY(46px) scale(0.92);
  position: relative;
  overflow: hidden;
  transition: transform var(--t-fast), border-color var(--t-fast);
}
.ig-card::before {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,.10), transparent 60%);
  opacity: 0;
  transition: opacity var(--t-fast);
}
.ig-card:hover {
  transform: translateY(-4px);
  border-color: rgba(96,165,250,.4);
}
.ig-card:hover::before { opacity: 1; }
.ig-card[data-i="0"] { animation: cardIn .9s cubic-bezier(.22,.8,.2,1) 3.4s forwards; }
.ig-card[data-i="1"] { animation: cardIn .9s cubic-bezier(.22,.8,.2,1) 3.6s forwards; }
.ig-card[data-i="2"] { animation: cardIn .9s cubic-bezier(.22,.8,.2,1) 3.8s forwards; }
.ig-card[data-i="3"] { animation: cardIn .9s cubic-bezier(.22,.8,.2,1) 4.0s forwards; }
.ig-card[data-i="4"] { animation: cardIn .9s cubic-bezier(.22,.8,.2,1) 4.2s forwards; }
.ig-icon {
  width: 40px; height: 40px;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(59,130,246,.30), rgba(139,92,246,.30));
  display: flex; align-items: center; justify-content: center;
  font-size: 20px;
  color: #93c5fd;
  box-shadow: 0 4px 16px rgba(59,130,246,.25);
}
.ig-name {
  font-size: clamp(13px, 1.25vw, 15px);
  font-weight: 700;
  color: #f1f5f9;
  letter-spacing: .3px;
}
.ig-desc {
  font-size: clamp(10px, .95vw, 12px);
  color: var(--text-mute);
  line-height: 1.45;
}

/* ---- 阶段 5：CTA ---- */
.intro-cta {
  opacity: 0;
  transform: translateY(20px);
  animation: ctaIn .8s cubic-bezier(.22,.8,.2,1) 5.0s forwards;
}
.intro-cta-btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 14px 38px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--accent), var(--accent-3));
  color: #fff;
  font-size: clamp(15px, 1.6vw, 18px);
  font-weight: 600;
  letter-spacing: 1px;
  box-shadow: 0 8px 24px rgba(59,130,246,.40);
  animation: ctaPulse 2.2s ease-in-out infinite 5s;
}
.intro-cta-btn i { font-size: 22px; }
.intro-cta-btn:hover { transform: translateY(-2px); box-shadow: 0 14px 36px rgba(59,130,246,.55); }

@keyframes titleReveal {
  to { opacity: 1; filter: blur(0); transform: translateY(0) scale(1); }
}
@keyframes lineIn {
  to { opacity: 1; transform: translateY(0); }
}
@keyframes subIn {
  to { opacity: 1; transform: translateY(0); }
}
@keyframes cardIn {
  to { opacity: 1; transform: translateY(0) scale(1); }
}
@keyframes ctaIn {
  to { opacity: 1; transform: translateY(0); }
}
@keyframes ctaPulse {
  0%, 100% { box-shadow: 0 8px 24px rgba(59,130,246,.40); }
  50%      { box-shadow: 0 14px 40px rgba(59,130,246,.65), 0 0 24px rgba(139,92,246,.45); }
}

/* ---- 跳过按钮 + 进度条 ---- */
.intro-skip {
  position: absolute;
  right: 22px;
  bottom: 26px;
  padding: 10px 22px;
  border-radius: 999px;
  background: rgba(255,255,255,.10);
  border: 1px solid rgba(255,255,255,.20);
  color: #cbd5e1;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 1px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: all var(--t-fast);
  opacity: 0;
  z-index: 5;
  cursor: pointer;
  animation: subIn .5s ease 1.2s forwards;
}
.intro-skip:hover {
  color: #fff;
  background: rgba(255,255,255,.20);
  transform: translateY(-2px);
}
.intro-skip:active { transform: translateY(0); }

.intro-progress {
  position: absolute;
  left: 50%;
  bottom: 30px;
  transform: translateX(-50%);
  width: min(240px, 40vw);
  height: 3px;
  border-radius: 999px;
  background: rgba(255,255,255,.10);
  overflow: hidden;
  z-index: 5;
  opacity: 0;
  animation: subIn .6s ease .3s forwards;
}
.intro-progress span {
  display: block;
  height: 100%;
  width: 0;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  transition: width 300ms linear;
}

/* ---- 响应式 ---- */
@media (max-width: 900px) {
  .intro-grid { grid-template-columns: repeat(3, minmax(0,1fr)); }
  .intro-sub { flex-direction: column; gap: 10px; }
  .intro-cta-btn i { display: none; }
}
@media (max-width: 560px) {
  .intro-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .ig-name { font-size: 14px; }
  .ig-desc { display: none; }   /* 小屏隐藏描述，卡片大幅变矮，内容可完整放入视口 */
  .ig-card { padding: 10px 8px; gap: 4px; }
  .intro-cta-btn { padding: 12px 28px; font-size: 14px; }
  .intro-skip { right: 14px; bottom: 20px; font-size: 12px; padding: 6px 14px; }
  /* 小屏垂直适配：标题更小 + 内边距收紧 + 内容垂直居中，避免顶部/底部裁切 */
  .intro-content {
    padding: 4vh 5vw 6vh;
    gap: clamp(10px, 1.8vh, 18px);
    justify-content: center;
  }
  .intro-title { font-size: clamp(26px, 8.5vw, 110px); }
  .intro-sub-logo { width: 44px; height: 44px; border-radius: 12px; }
  .intro-sub { gap: 8px; }
  .intro-sub-text { font-size: 13px; }
}



/* =================================================================
 * 教程页（模板渲染）
 * ================================================================= */
/* 修复：section.page 只做定位；tutorial-grid 负责布局，不再用 .tutorial 做双重定位 */
.tutorial-grid {
  width: min(1120px, 92vw);
  display: grid;
  gap: clamp(22px, 4vh, 52px);
  align-items: center;
  justify-content: center;
}
.tutorial-grid.layout-left    { grid-template-columns: 1.05fr .95fr; }
.tutorial-grid.layout-right   { grid-template-columns: .95fr 1.05fr; }
.tutorial-grid.layout-center  { grid-template-columns: 1fr; justify-items: center; text-align: center; }
.tutorial-grid.layout-split   { grid-template-columns: 1fr 1fr; }

.t-content {
  display: flex; flex-direction: column; gap: 16px;
  min-width: 0;
}
.t-tag {
  display: inline-block;
  font-size: 12px;
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(255,255,255,.08);
  color: #fff;
  width: max-content;
  letter-spacing: 1px;
  border: 1px solid rgba(255,255,255,.16);
}
.t-title {
  font-size: clamp(22px, 3.4vw, 42px);
  font-weight: 700;
  line-height: 1.15;
}
.t-subtitle {
  font-size: clamp(14px, 1.4vw, 18px);
  color: var(--text-mute);
}
.t-desc {
  font-size: clamp(13px, 1.2vw, 16px);
  color: var(--text);
  opacity: .85;
  white-space: normal;
  word-wrap: break-word;
  text-align: left;
}
.t-desc ul { padding-left: 20px; margin: 6px 0; }
.t-desc p { margin: 6px 0; }
.t-desc code {
  background: rgba(255,255,255,.08);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: 'JetBrains Mono', Consolas, Menlo, monospace;
  font-size: .92em;
}

.t-media {
  position: relative;
  border-radius: var(--radius-l);
  overflow: hidden;
  background: rgba(255,255,255,.04);
  box-shadow: var(--shadow-2);
  border: 1px solid rgba(255,255,255,.08);
  aspect-ratio: 16 / 10;
  display: flex; align-items: center; justify-content: center;
}
.t-media video,
.t-media img {
  width: 100%; height: 100%;
  object-fit: cover;
}
/* 一页多视频：纵向列表 */
.t-media-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.t-media-list .t-media {
  width: 100%;
  aspect-ratio: 16 / 10;
  max-height: 42vh;
}
@media (max-width: 900px) {
  .t-media-list .t-media { max-height: 38vh; }
}
.t-media-empty {
  display: flex; flex-direction: column; gap: 10px;
  align-items: center; justify-content: center;
  color: var(--text-dim);
}
.t-media-empty i { font-size: 40px; opacity: .6; }
.t-media-empty span { font-size: 14px; }

.t-features {
  display: grid; gap: 10px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 6px;
  text-align: left;
}
.t-feature-item {
  display: flex; align-items: flex-start; gap: 8px;
  font-size: clamp(12px, 1.2vw, 15px);
  color: var(--text);
  opacity: .92;
}
.t-feature-item i { color: var(--accent, var(--accent)); font-size: 18px; line-height: 1; margin-top: 4px; }

.tutorial-grid.layout-right .t-content { order: 2; }
.tutorial-grid.layout-right .t-media   { order: 1; }

.tutorial-grid.layout-center .t-media { width: min(760px, 100%); }
.tutorial-grid.layout-center .t-features { grid-template-columns: repeat(3, minmax(0,1fr)); width: min(860px, 100%); }
.tutorial-grid.layout-center .t-desc { text-align: left; }

.tutorial-grid.layout-split .t-media:nth-of-type(2) {
  box-shadow: none;
  background: linear-gradient(135deg, rgba(59,130,246,.16), rgba(139,92,246,.16));
}

/* ---- 界面教程 layout（4 种变体：左 / 右 / 顶部条 / 卡片网格） ---- */
.tutorial-grid.layout-tutorial {
  grid-template-columns: 240px 1fr;
  gap: clamp(20px, 3vw, 36px);
  width: min(1140px, 95vw);
  align-items: start;     /* 顶部对齐，避免内容溢出居中后被裁切 */
  max-height: 100%;
  overflow: visible;
}
.tut-main {
  display: flex; flex-direction: column;
  gap: 20px;
  min-width: 0;
  width: 100%;
  max-height: calc(100vh - 12vh);    /* 保持视口内，不被裁切 */
  overflow-y: auto;
  padding-right: 6px;
  /* 隐藏滚动条但保持可滚动 */
  scrollbar-width: thin;
  scrollbar-color: rgba(255,255,255,.2) transparent;
}
.tut-main::-webkit-scrollbar { width: 6px; }
.tut-main::-webkit-scrollbar-track { background: transparent; }
.tut-main::-webkit-scrollbar-thumb {
  background: rgba(255,255,255,.15);
  border-radius: 999px;
}

/* 视频面板：单视频播放器（点击左侧步骤导航切换） */
.tut-video-panel {
  border-radius: 16px;
  background: linear-gradient(135deg, rgba(255,255,255,.04), rgba(255,255,255,.02));
  border: 1px solid rgba(255,255,255,.08);
  overflow: hidden;
}
.tut-video-title {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border-bottom: 1px solid rgba(255,255,255,.06);
}
.tut-video-title-text {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
}
.tut-video-panel .t-media {
  width: 100%;
  display: block;             /* block 布局：video 顶部对齐，避免 flex 居中偏移导致超出 */
  text-align: center;
  aspect-ratio: auto;         /* 覆盖通用 .t-media 的 16/10，高度由视频实际尺寸决定 */
  /* 深色玻璃渐变（非纯黑），与页面风格融合，视频等比显示时留边不刺眼 */
  background: linear-gradient(135deg, rgba(15,23,42,.35), rgba(2,6,23,.55));
  overflow: hidden;
}
/* 视频/图片自适应：按自身比例等比缩放，完整展示（max-width/max-height 双约束） */
.tut-video-panel .t-media video,
.tut-video-panel .t-media img {
  display: block;
  margin: 0 auto;             /* 水平居中 */
  width: auto; height: auto;
  max-width: 100%;
  max-height: 50vh;
  object-fit: contain;
}
/* 默认（left/right/top）：视频可用高度大一点 */
.tut-variant-left .tut-video-panel .t-media video,
.tut-variant-right .tut-video-panel .t-media video,
.tut-variant-top .tut-video-panel .t-media video {
  max-height: 50vh;
}
/* 顶部步骤条变体：为步骤条+标题留空间，视频高度随视口动态压缩（小高度桌面一屏完整） */
.tut-variant-top .tut-video-panel .t-media video {
  max-height: min(50vh, calc(100vh - 340px));
}
/* 卡片网格变体：为卡片+标题留空间，视频高度收紧但仍完整显示 */
.tut-variant-grid .tut-video-panel .t-media video,
.tut-variant-grid .tut-video-panel .t-media img {
  max-height: min(38vh, calc(100vh - 430px));
}
.tut-no-video {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 60px 20px;
  color: var(--text-dim);
  font-size: 14px;
}
.tut-no-video i { font-size: 30px; opacity: .6; }

/* 导航项可点击（hover + active 反馈） */
.tut-toc-list li,
.tut-toc-bar li,
.tut-card-item {
  cursor: pointer;
  user-select: none;
}
.tut-toc-list li.is-active { background: rgba(59,130,246,.18); color: #fff; font-weight: 600; }
.tut-card-item.is-active {
  border-color: rgba(96,165,250,.45);
  background: linear-gradient(135deg, rgba(59,130,246,.10), rgba(139,92,246,.06));
}
.tut-card-item.is-active .tut-card-text { color: #fff; }

.tut-block-num {
  width: 28px; height: 28px;
  flex-shrink: 0;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-3));
  color: #fff;
  font-size: 13px;
  font-weight: 700;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 4px 12px rgba(59,130,246,.25);
}

/* 变体：右目录（左内容，右目录） */
.tutorial-grid.layout-tutorial.tut-variant-right {
  grid-template-columns: 1fr 240px;
}
/* 变体：顶部步骤条（目录横向在顶部） */
.tutorial-grid.layout-tutorial.tut-variant-top {
  grid-template-columns: 1fr;
  gap: 14px;
}
/* 变体：底部步骤条（视频在上，步骤条在下） */
.tutorial-grid.layout-tutorial.tut-variant-bottom {
  grid-template-columns: 1fr;
  gap: 14px;
}
/* 变体：选项卡（顶部 tab 式导航） */
.tutorial-grid.layout-tutorial.tut-variant-tabs {
  grid-template-columns: 1fr;
  gap: 14px;
}
/* 变体：时间线（左侧垂直步骤线） */
.tutorial-grid.layout-tutorial.tut-variant-timeline {
  grid-template-columns: 260px 1fr;
  gap: clamp(20px, 3vw, 36px);
}
/* 变体：简洁胶囊（视频全宽 + 底部胶囊导航） */
.tutorial-grid.layout-tutorial.tut-variant-mini {
  grid-template-columns: 1fr;
  gap: 14px;
  width: min(900px, 95vw);
}
/* top 变体：副标题标签 + 主标题横排，避免与步骤条纵向拥挤/叠加 */
.tut-variant-top .tut-header {
  flex-direction: row;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}
.tut-variant-top .t-tag { flex-shrink: 0; }
.tut-variant-top .t-title {
  font-size: clamp(20px, 2.6vw, 30px);
  line-height: 1.2;
}

/* ---- 选项卡（tabs）导航 ---- */
.tut-tab-bar {
  flex-wrap: nowrap;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  gap: 6px;
  padding: 8px;
  border-radius: 14px;
}
.tut-tab-bar li {
  flex: 0 0 auto;
  max-width: none;
  padding: 9px 18px;
  border-radius: 10px;
  background: rgba(255,255,255,.04);
  border: 1px solid rgba(255,255,255,.07);
  transition: background var(--t-fast), color var(--t-fast), border-color var(--t-fast);
}
.tut-tab-bar li.is-active {
  background: rgba(59,130,246,.2);
  border-color: rgba(96,165,250,.45);
  color: #fff;
}
.tut-tab-bar li.is-active .tut-toc-num { background: var(--accent); color: #fff; }

/* ---- 时间线（timeline）导航 ---- */
.tut-timeline-list {
  position: relative;
}
.tut-timeline-list::before {
  content: '';
  position: absolute;
  left: 19px; top: 12px; bottom: 12px;
  width: 2px;
  background: linear-gradient(180deg, rgba(96,165,250,.4), rgba(139,92,246,.15));
  border-radius: 2px;
}
.tut-timeline-list li {
  position: relative;
  padding: 10px 10px 10px 46px;
}
.tut-timeline-list li .tut-toc-num {
  position: absolute;
  left: 6px;
  top: 9px;
  background: rgba(255,255,255,.08);
}
.tut-timeline-list li.is-active .tut-toc-num {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 0 0 4px rgba(96,165,250,.15);
}

/* ---- 简洁胶囊（mini）导航 ---- */
.tut-mini-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  padding: 12px;
  border-radius: 14px;
  background: linear-gradient(135deg, rgba(255,255,255,.04), rgba(255,255,255,.02));
  border: 1px solid rgba(255,255,255,.08);
}
.tut-mini-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border-radius: 999px;
  font-size: 12px;
  color: var(--text-mute);
  border: 1px solid rgba(255,255,255,.08);
  background: rgba(255,255,255,.03);
  cursor: pointer;
  white-space: nowrap;
  transition: background var(--t-fast), color var(--t-fast), border-color var(--t-fast);
}
.tut-mini-item.is-active {
  background: rgba(59,130,246,.2);
  border-color: rgba(96,165,250,.4);
  color: #fff;
  font-weight: 600;
}

/* 底部/选项卡/简洁 变体视频高度也随视口动态压缩 */
.tut-variant-bottom .tut-video-panel .t-media video,
.tut-variant-tabs .tut-video-panel .t-media video,
.tut-variant-timeline .tut-video-panel .t-media video,
.tut-variant-mini .tut-video-panel .t-media video {
  max-height: min(50vh, calc(100vh - 340px));
}
.tut-variant-timeline .tut-video-panel .t-media video { max-height: min(50vh, calc(100vh - 300px)); }
.tut-variant-mini .tut-video-panel .t-media video { max-height: min(52vh, calc(100vh - 300px)); }

.tut-toc-bar {
  list-style: none;
  padding: 14px 18px;
  margin: 0;
  border-radius: 16px;
  background: linear-gradient(135deg, rgba(255,255,255,.06), rgba(255,255,255,.02));
  border: 1px solid rgba(255,255,255,.10);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  display: flex; flex-wrap: wrap; gap: 18px;
  align-items: center;
  /* 不用 sticky：避免滚动时步骤条覆盖下方副标题/内容 */
  position: relative;
  z-index: 5;
}
.tut-toc-bar li {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px;
  color: var(--text-mute);
  cursor: pointer;
  flex: 0 1 auto;
  max-width: 220px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transition: color var(--t-fast);
}
.tut-toc-bar li:hover, .tut-toc-bar li.is-active { color: #fff; }
.tut-toc-bar li.is-active { font-weight: 600; }
/* 序号由 JS 生成的 span.tut-toc-num 提供，这里不再用 ::before counter（避免双序号） */
.tut-toc-bar li .tut-toc-num {
  background: rgba(255,255,255,.08);
}
.tut-toc-bar li.is-active .tut-toc-num {
  background: var(--accent);
  color: #fff;
}
.tut-toc-bar { counter-reset: tut-step; }

/* 变体：卡片网格（步骤卡片化，无目录） */
.tutorial-grid.layout-tutorial.tut-variant-grid {
  grid-template-columns: 1fr;
  gap: 14px;
}
/* grid 变体：限制视频高度，保证 标题+卡片+视频 全部一屏完整显示（不裁切） */
.tut-variant-grid .tut-cards-grid {
  margin: 4px 0;
  gap: 10px;
}
.tut-variant-grid .tut-card-item {
  padding: 12px 14px;
}
.tut-variant-grid .tut-main {
  gap: 14px;
}
.tut-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
  margin: 16px 0;
}
.tut-card-item {
  display: flex; align-items: flex-start; gap: 12px;
  padding: 16px;
  border-radius: 14px;
  background: linear-gradient(135deg, rgba(255,255,255,.05), rgba(255,255,255,.02));
  border: 1px solid rgba(255,255,255,.08);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: transform var(--t-fast), border-color var(--t-fast);
}
.tut-card-item:hover {
  transform: translateY(-3px);
  border-color: rgba(96,165,250,.4);
}
.tut-card-icon {
  width: 30px; height: 30px; flex-shrink: 0;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-3));
  display: flex; align-items: center; justify-content: center;
  font-size: 12px;
  font-weight: 700;
  color: #fff;
  position: relative;
}
.tut-card-icon::before {
  content: counter(tut-card);
  counter-increment: tut-card;
}
.tut-cards-grid { counter-reset: tut-card; }
.tut-card-text {
  font-size: 14px;
  color: var(--text);
  line-height: 1.6;
  flex: 1;
  min-width: 0;
}

/* 原有左侧目录样式（left/right 变体共用） */
.tut-toc {
  position: sticky;
  top: 5vh;
  padding: 24px;
  border-radius: 18px;
  background: linear-gradient(135deg, rgba(255,255,255,.06), rgba(255,255,255,.02));
  border: 1px solid rgba(255,255,255,.10);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  align-self: start;
  max-height: 80vh;
  overflow-y: auto;
}
.tut-toc-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(255,255,255,.08);
  letter-spacing: 1px;
}
.tut-toc-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex; flex-direction: column;
  gap: 6px;
}
.tut-toc-list li {
  display: flex; align-items: center;
  gap: 10px;
  padding: 8px 10px;
  border-radius: 8px;
  font-size: 13px;
  color: var(--text-mute);
  cursor: pointer;
  transition: background var(--t-fast), color var(--t-fast);
}
.tut-toc-list li:hover { background: rgba(255,255,255,.04); color: #fff; }
.tut-toc-list li.is-active {
  background: rgba(59,130,246,.18);
  color: #fff;
  font-weight: 600;
}
.tut-toc-num {
  width: 20px; height: 20px;
  border-radius: 50%;
  background: rgba(255,255,255,.08);
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 11px;
  flex-shrink: 0;
}
.tut-toc-list li.is-active .tut-toc-num {
  background: var(--accent);
  color: #fff;
}
.tut-main {
  display: flex; flex-direction: column;
  gap: 24px;
  min-width: 0;
}
.tut-header {
  display: flex; flex-direction: column; gap: 12px;
}
.tut-body { display: flex; flex-direction: column; gap: 12px; }
.tut-steps-title {
  font-size: 13px;
  font-weight: 700;
  color: #93c5fd;
  letter-spacing: 1px;
  text-transform: uppercase;
}
.tut-steps {
  list-style: none;
  counter-reset: step;
  display: flex; flex-direction: column;
  gap: 10px;
  padding: 0;
  margin: 0;
}
.tut-step {
  counter-increment: step;
  padding: 12px 16px 12px 48px;
  border-radius: 10px;
  background: rgba(255,255,255,.04);
  border: 1px solid rgba(255,255,255,.06);
  position: relative;
  font-size: 14px;
  color: var(--text);
  line-height: 1.6;
}
.tut-step::before {
  content: counter(step);
  position: absolute;
  left: 14px;
  top: 11px;
  width: 24px; height: 24px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-3));
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  display: flex; align-items: center; justify-content: center;
}

@media (max-width: 900px) {
  .tutorial-grid.layout-tutorial { grid-template-columns: 1fr; }
  .tutorial-grid.layout-tutorial.tut-variant-right { grid-template-columns: 1fr; }
  .tutorial-grid.layout-tutorial.tut-variant-timeline { grid-template-columns: 1fr; }
  .tut-variant-mini { width: 95vw; }
  .tut-toc { position: relative; top: auto; max-height: none; }

  /* 移动端：左侧/右侧/时间线目录改为紧凑"胶囊步骤条"（不占超高，避免与内容重叠） */
  .tut-toc {
    width: 100%;
    padding: 10px 12px;
    border-radius: 12px;
  }
  .tut-toc-title { display: none; }
  .tut-toc-list {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 6px;
  }
  .tut-toc-list li {
    padding: 5px 10px;
    font-size: 12px;
    border-radius: 999px;
    border: 1px solid rgba(255,255,255,.08);
    background: rgba(255,255,255,.04);
  }
  .tut-toc-list li.is-active {
    background: rgba(59,130,246,.22);
    border-color: rgba(96,165,250,.4);
  }
  /* 时间线移动端：去掉连接线（胶囊化） */
  .tut-timeline-list::before { display: none; }
  .tut-timeline-list li { padding: 5px 10px; }
  .tut-timeline-list li .tut-toc-num { position: static; }

  /* 移动端教程页：整页可滚动（目录 + 视频面板并列超高时不再被裁切） */
  .page.tut-variant-left,
  .page.tut-variant-right,
  .page.tut-variant-top,
  .page.tut-variant-bottom,
  .page.tut-variant-tabs,
  .page.tut-variant-grid,
  .page.tut-variant-timeline,
  .page.tut-variant-mini {
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    align-items: start;
    padding: 16px;
  }
  .tut-main {
    max-height: none;
    overflow-y: visible;
    gap: 14px;
  }
  .tut-toc { width: 100%; padding: 16px; }
  .tut-toc-list { flex-direction: row; flex-wrap: wrap; gap: 6px; }
  .tut-toc-list li { flex: 0 1 auto; }
  /* 顶部/底部步骤条、选项卡：横排可横向滚动 */
  .tut-toc-bar {
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    justify-content: flex-start;
    padding: 12px;
  }
  .tut-toc-bar li { flex: 0 0 auto; max-width: 170px; }
  /* 移动端：视频按比例自适应，高度收紧保证完整 */
  .tut-video-panel .t-media video,
  .tut-video-panel .t-media img { max-height: 38vh; }
}

/* =================================================================
 * 致谢页
 * ================================================================= */
.page-thanks .thanks-inner {
  width: min(640px, 100%);
  padding: 0 24px;
}
.thanks-card {
  padding: 48px 32px;
  border-radius: var(--radius-l);
  background: linear-gradient(135deg, rgba(255,255,255,.06), rgba(255,255,255,.02));
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid rgba(255,255,255,.10);
  text-align: center;
  display: flex; flex-direction: column; align-items: center; gap: 16px;
  box-shadow: var(--shadow-2);
}
.thanks-icon {
  font-size: 56px;
  color: #f43f5e;
  filter: drop-shadow(0 6px 18px rgba(244,63,94,.55));
  animation: heartBeat 1.5s ease infinite;
}
@keyframes heartBeat {
  0%, 100% { transform: scale(1); }
  50%      { transform: scale(1.12); }
}
.thanks-card h2 {
  font-size: clamp(22px, 3vw, 32px);
  font-weight: 700;
  background: linear-gradient(135deg, #fff, #93c5fd);
  -webkit-background-clip: text; background-clip: text;
  color: transparent;
}
.thanks-card p {
  color: var(--text-mute);
  font-size: clamp(13px, 1.3vw, 15px);
  line-height: 1.8;
  white-space: pre-wrap;
}
/* 联系方式（微信 / QQ / 邮箱 / 电话） */
.thanks-contacts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  width: 100%;
  margin-top: 14px;
}
.thanks-contact {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  border-radius: 14px;
  background: linear-gradient(135deg, rgba(255,255,255,.05), rgba(255,255,255,.02));
  border: 1px solid rgba(255,255,255,.08);
  transition: transform var(--t-fast), border-color var(--t-fast);
  text-align: left;
}
.thanks-contact:hover {
  transform: translateY(-2px);
  border-color: rgba(96,165,250,.35);
}
.thanks-contact i {
  width: 38px; height: 38px;
  flex-shrink: 0;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 19px;
  background: linear-gradient(135deg, rgba(59,130,246,.25), rgba(139,92,246,.15));
  color: #93c5fd;
}
.thanks-contact-body {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}
.thanks-contact-label {
  font-size: 11px;
  color: var(--text-dim);
  letter-spacing: 1px;
}
.thanks-contact-value {
  font-size: 13px;
  color: var(--text);
  font-weight: 500;
  word-break: break-all;
}
.thanks-btn {
  margin-top: 8px;
  padding: 12px 32px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--accent), var(--accent-3));
  color: #fff;
  font-weight: 600;
  letter-spacing: 1px;
  transition: transform var(--t-fast), box-shadow var(--t-fast);
  box-shadow: 0 10px 24px rgba(59,130,246,.35);
}
.thanks-btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 18px 36px rgba(59,130,246,.55);
}

/* =================================================================
 * 侧边导航
 * ================================================================= */
.side-nav {
  position: fixed;
  right: clamp(14px, 2vw, 24px);
  top: 50%;
  transform: translateY(-50%);
  z-index: 100;
}
.side-nav ul {
  list-style: none;
  display: flex; flex-direction: column;
  gap: 12px;
  padding: 12px 8px;
  border-radius: 999px;
  background: rgba(15,23,42,.42);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,.08);
}
.side-nav li button {
  width: 10px; height: 10px;
  border-radius: 999px;
  background: rgba(255,255,255,.20);
  transition: all var(--t-fast);
  display: block;
}
.side-nav li button:hover { background: rgba(255,255,255,.45); }
.side-nav li.is-active button {
  background: var(--accent);
  width: 30px;
  box-shadow: 0 0 12px var(--accent);
}

/* =================================================================
 * 滚动提示
 * ================================================================= */
.scroll-hint {
  position: fixed;
  left: 50%;
  bottom: 30px;
  transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center; gap: 6px;
  color: var(--text-mute);
  font-size: 12px;
  letter-spacing: 2px;
  opacity: .7;
  z-index: 90;
  pointer-events: none;
  transition: opacity var(--t-mid);
}
.scroll-hint i { font-size: 20px; }
.scroll-hint .ri-arrow-down-line {
  animation: arrowBounce 1.6s ease-in-out infinite;
}
@keyframes arrowBounce {
  0%, 100% { transform: translateY(0); opacity: .8; }
  50%      { transform: translateY(6px); opacity: .3; }
}

/* =================================================================
 * 自定义 HTML 注入容器
 * ================================================================= */
#custom-head, #custom-body { display: contents; }

/* =================================================================
 * 响应式
 * ================================================================= */
@media (max-width: 900px) {
  .tutorial-grid.layout-left,
  .tutorial-grid.layout-right,
  .tutorial-grid.layout-split {
    grid-template-columns: 1fr;
  }
  .tutorial-grid.layout-right .t-content { order: 1; }
  .tutorial-grid.layout-right .t-media   { order: 2; }
  .tutorial-grid.layout-center .t-features { grid-template-columns: 1fr 1fr; }
  .downloads { grid-template-columns: 1fr 1fr; }
  /* 移动端：显示侧边圆点导航（半透明，点击可跳转任意页——解决微信手势被拦截时无法回翻的问题） */
  .side-nav { display: block; right: 8px; }
  .side-nav ul { gap: 10px; padding: 10px 6px; background: rgba(15,23,42,.35); }
  .side-nav li button { width: 16px; height: 16px; background: rgba(255,255,255,.35); border: 1px solid rgba(255,255,255,.15); }
  .side-nav li.is-active button { width: 16px; height: 16px; background: var(--accent); box-shadow: 0 0 14px var(--accent); }
  /* 移动端：显示"向下滑动"提示（隐藏鼠标图标，适配触屏），提示用户下滑看教程 */
  .scroll-hint { display: flex; bottom: 18px; font-size: 11px; gap: 4px; }
  .scroll-hint .ri-mouse-line { display: none; }
  .scroll-hint i:last-child { font-size: 18px; }
  .intro-progress { bottom: 24px; }
}
@media (max-width: 560px) {
  .downloads { grid-template-columns: 1fr 1fr; }
  .tutorial-grid.layout-center .t-features { grid-template-columns: 1fr; }
  .t-feature-item { font-size: 14px; }
  .intro-logo-3d { width: min(190px, 54vw); }
  .intro-skip { right: 14px; bottom: 20px; font-size: 12px; padding: 6px 14px; }
  .hero-inner { gap: 14px; padding: 12px 14px; }
  .hero-shot-wrap { max-height: 34vh; }
  .hero-screenshot { max-height: 34vh; }
  .hero-title { font-size: 22px; }
  .hero-subtitle { font-size: 13px; }
  .dl-btn { padding: 10px 8px; }
  .thanks-card { padding: 36px 22px; }
  .thanks-contacts { grid-template-columns: 1fr; }
}

/* 低高度屏幕适配：保证 4 个下载按钮始终可见 */
@media (max-height: 820px) {
  .hero-shot-wrap   { max-height: 40vh; }
  .hero-screenshot  { max-height: 40vh; }
  .hero-title       { font-size: clamp(20px, 2.6vw, 30px); }
  .hero-inner       { gap: clamp(10px, 2vh, 16px); padding: 3vh 24px; }
}
@media (max-height: 700px) {
  .hero-shot-wrap   { max-height: 34vh; }
  .hero-screenshot  { max-height: 34vh; }
  .downloads        { gap: 8px; }
  .dl-btn           { padding: 10px 14px; }
}

/* 低高度屏幕完整适配：保证 768px 高度也能看到全部 hero（截图+标题+4 按钮） */
@media (max-height: 820px) {
  .hero-inner { gap: clamp(6px, 1.4vh, 14px); padding: clamp(8px, 2vh, 20px) 24px; }
  .hero-shot-wrap { max-height: 40vh; }
  .hero-screenshot { max-height: 40vh; }
  .hero-title { font-size: clamp(18px, 2.4vw, 30px); }
  .hero-title { line-height: 1.2; }
  .hero-subtitle { font-size: clamp(11px, 1.2vw, 14px); margin-top: 2px; }
  .downloads { gap: 8px; }
  .dl-btn { padding: 10px 12px; }
  .dl-btn .dl-name { font-size: 13px; }
  .dl-btn .dl-meta { font-size: 11px; }
}
@media (max-height: 680px) {
  .hero-inner { gap: 6px; padding: 6px 24px 10px; }
  .hero-shot-wrap { max-height: 34vh; }
  .hero-screenshot { max-height: 34vh; }
  .hero-title { font-size: 18px; }
  .intro-stage .intro-content { gap: clamp(14px, 2vh, 24px); }
  .intro-stage .intro-title { font-size: clamp(32px, 6vw, 70px); }
  .intro-stage .intro-grid { gap: 8px; }
}
/* 横向溢出保护 */
.page { max-width: 100vw; }
.intro-content { max-width: 100vw; }
.hero-inner { max-width: 100vw; }

/* 隐藏 app */
.app.hidden { opacity: 0; }
.app { opacity: 1; transition: opacity 600ms ease; }

/* 减弱偏好动画 */
/* 说明：原 prefers-reduced-motion 规则会把所有动画/过渡禁用为 0.001ms，
   导致系统关闭"动画效果"（Windows 辅助功能）时整站动画消失（intro 直接跳转、hero 无过渡）。
   本网站动画是核心展示，删除该规则，确保动画始终可见。 */