/* =====================================================
   语崽智脑 · 新手指引官网
   分区：
   1. 基础与变量   2. 背景光晕   3. 布局与排版
   4. 按钮         5. Hero      6. 概念卡
   7. 设备框（手机/电脑/双机）
   8. 框内小剧场通用件（表单/终端/卡片/气泡/手指/活性灯）
   9. 循环小动画（闹铃/朗读/换班/复制粘贴/键盘）
   10. FAQ        11. 页脚     12. 入场与无障碍
   ===================================================== */

/* ---------- 1. 基础与变量 ---------- */
:root{
  --bg:#0f1226;
  --tx:#e8ebff;
  --dim:#9aa3c7;
  --card:rgba(255,255,255,.05);
  --line:rgba(255,255,255,.09);
  --g1:#6366f1;
  --g2:#22d3ee;
  --grad:linear-gradient(135deg,#6366f1,#22d3ee);
  --ok:#34d399;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
html,body{overflow-x:hidden;overflow-x:clip}
body{
  background:var(--bg);
  color:var(--tx);
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  -webkit-font-smoothing:antialiased;
  line-height:1.5;
}
img{max-width:100%}
a{-webkit-tap-highlight-color:transparent}

/* ---------- 2. 背景光晕 ---------- */
.bgfx{position:fixed;inset:0;overflow:hidden;z-index:-1;pointer-events:none}
.glow{position:absolute;border-radius:50%;filter:blur(90px)}
.glow.g1{width:340px;height:340px;background:rgba(99,102,241,.30);top:-90px;left:-110px}
.glow.g2{width:300px;height:300px;background:rgba(34,211,238,.20);top:42%;right:-130px}

/* ---------- 3. 布局与排版 ---------- */
.col{max-width:480px;margin:0 auto;padding:0 18px}
section{margin:76px 0}
h2{font-size:27px;text-align:center;font-weight:800}
.sec-sub{text-align:center;color:var(--dim);font-size:14px;margin-top:8px}
.step,.feat{margin-top:48px}
.step h3,.feat h3{font-size:21px;line-height:1.45;font-weight:800}
.desc{color:var(--dim);font-size:14.5px;line-height:1.8;margin-top:10px}
.desc b{color:var(--tx)}
code{background:#1c2348;border-radius:6px;padding:1px 6px;font-size:.92em;font-family:ui-monospace,Menlo,monospace}
.step-tag{
  display:inline-block;font-size:12px;font-weight:700;color:var(--g2);
  background:rgba(34,211,238,.10);border:1px solid rgba(34,211,238,.30);
  border-radius:20px;padding:5px 12px;margin-bottom:12px;
}
.f-num{font-size:12px;color:var(--g2);font-weight:800;letter-spacing:2px;margin-bottom:6px}
.grad{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.glass{
  background:var(--card);border:1px solid var(--line);border-radius:18px;
  padding:16px;margin-top:16px;
  backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);
}
.mini-note{text-align:center;font-size:12px;color:var(--dim);margin-top:12px}

/* ---------- 4. 按钮 ---------- */
.btn{
  display:block;text-align:center;text-decoration:none;font-weight:700;
  border-radius:14px;padding:15px 20px;font-size:16px;color:#fff;transition:transform .15s;
}
.btn.primary{background:var(--grad);box-shadow:0 10px 28px rgba(79,140,243,.35)}
.btn.primary:active{transform:scale(.97)}
.btn.ghost{background:var(--card);border:1px solid var(--line);color:var(--tx)}
.btn.block{width:100%;margin-top:14px}
.replay{
  display:block;margin:14px auto 0;background:none;border:1px solid var(--line);
  color:var(--dim);border-radius:20px;padding:8px 18px;font-size:13px;cursor:pointer;
  font-family:inherit;
}
.replay:active{color:var(--tx);border-color:var(--tx)}

/* ---------- 5. Hero ---------- */
.hero{
  min-height:92vh;display:flex;flex-direction:column;align-items:center;
  justify-content:center;text-align:center;padding:40px 0 24px;
}
.logo{width:76px;filter:drop-shadow(0 8px 24px rgba(99,102,241,.45))}
.brand{margin-top:12px;font-size:14px;letter-spacing:4px;color:var(--dim)}
.hero h1{font-size:29px;line-height:1.35;margin-top:14px;font-weight:800;padding:0 4px}
.sub{margin-top:16px;font-size:15px;line-height:1.8;color:var(--dim)}
.cta{display:flex;flex-direction:column;gap:12px;width:100%;margin-top:28px}
.scroll-hint{margin-top:36px;color:var(--dim);font-size:12px;animation:hint 2s ease-in-out infinite}
@keyframes hint{50%{transform:translateY(6px);opacity:.55}}

/* ---------- 6. 概念卡 ---------- */
.cards3{display:flex;flex-direction:column;gap:14px;margin-top:24px}
.ccard{
  background:var(--card);border:1px solid var(--line);border-radius:18px;padding:20px;
  backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);
}
.cicon{font-size:30px}
.ccard h3{font-size:17px;margin-top:10px}
.ccard p{font-size:14px;color:var(--dim);line-height:1.75;margin-top:6px}

/* ---------- 7. 设备框 ---------- */
.device{margin:24px auto 8px;position:relative}
/* 手机框：圆角竖框 + 刘海 */
.phone{
  width:240px;height:490px;border-radius:38px;padding:10px;
  background:linear-gradient(160deg,#20264d,#10142e);
  border:1px solid rgba(255,255,255,.14);
  box-shadow:0 24px 60px rgba(0,0,0,.5),inset 0 1px 0 rgba(255,255,255,.12);
}
.phone::before{
  content:'';position:absolute;top:19px;left:50%;transform:translateX(-50%);
  width:76px;height:14px;border-radius:8px;background:#05070f;z-index:5;
}
.phone .stage{position:relative;width:100%;height:100%;border-radius:29px;background:#0a0d1f;overflow:hidden}
/* 小手机（双机联动用） */
.phone.sm{width:148px;height:306px;border-radius:26px;padding:7px}
.phone.sm::before{top:14px;width:48px;height:9px;border-radius:5px}
.phone.sm .stage{border-radius:20px}
/* 电脑框：宽框 + 底座 */
.mac{
  width:100%;max-width:340px;border-radius:12px 12px 0 0;padding:8px 8px 0;
  background:linear-gradient(160deg,#20264d,#10142e);
  border:1px solid rgba(255,255,255,.14);
  box-shadow:0 24px 60px rgba(0,0,0,.5);
}
.mac .stage{position:relative;width:100%;height:216px;border-radius:7px 7px 0 0;background:#070a18;overflow:hidden}
.mac::after{
  content:'';display:block;height:14px;margin:0 -18px;
  background:linear-gradient(#2a3157,#171c3a);
  border-radius:0 0 14px 14px;border:1px solid rgba(255,255,255,.10);border-top:none;
}
/* 双机联动布局 */
.duo{position:relative;max-width:360px;margin:24px auto 8px;padding-bottom:66px}
.duo .mac{margin:0}
.duo .phone.sm{position:absolute;right:-2px;bottom:0;margin:0}
.duo .term-body{padding-right:150px}

/* ---------- 8. 框内小剧场通用件 ---------- */
/* 手机屏内页面 */
.mock{position:absolute;inset:0;padding:40px 12px 12px}
.phone.sm .mock{padding:28px 8px 8px}
.mp-head{font-size:13px;font-weight:700;text-align:center;margin-bottom:12px}
.phone.sm .mp-head{font-size:10px;margin-bottom:8px}
.mp-label{font-size:10.5px;color:var(--dim);margin:10px 2px 5px}
.mp-tip{font-size:9.5px;color:var(--dim);text-align:center;margin-top:12px}
.field{
  height:36px;border-radius:10px;border:1px solid var(--line);
  background:rgba(255,255,255,.04);display:flex;align-items:center;
  padding:0 10px;font-size:14px;letter-spacing:1.5px;
}
.mp-btn{
  height:38px;border-radius:10px;background:var(--grad);display:flex;
  align-items:center;justify-content:center;font-weight:700;font-size:14px;
  margin-top:16px;transition:.3s;
}
.mp-btn.busy{filter:saturate(.5);transform:scale(.97)}
/* 光标 */
.caret{width:2px;height:16px;background:var(--g2);margin-left:2px;animation:blink 1s steps(1) infinite}
.caret.light{display:inline-block;vertical-align:-2px}
@keyframes blink{50%{opacity:0}}
/* 短信横幅 */
.sms{
  position:absolute;top:-80px;left:10px;right:10px;z-index:6;
  background:#1c2348;border:1px solid var(--line);border-radius:14px;
  padding:10px 12px;font-size:10.5px;line-height:1.5;display:flex;gap:8px;
  box-shadow:0 10px 30px rgba(0,0,0,.5);
  transition:top .55s cubic-bezier(.2,.9,.3,1.2);
}
.sms.show{top:46px}
.sms b{flex:none}
.sms-code{color:var(--g2);font-size:12px;letter-spacing:1px}
/* 登录成功 */
.login-ok{
  position:absolute;inset:0;z-index:7;background:rgba(10,13,31,.94);
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  gap:12px;font-size:17px;font-weight:800;opacity:0;transition:.4s;pointer-events:none;
}
.login-ok.show{opacity:1}
.ok-ball{
  width:54px;height:54px;border-radius:50%;color:#05231a;font-size:28px;
  background:linear-gradient(135deg,#34d399,#22d3ee);
  display:flex;align-items:center;justify-content:center;
  animation:pop .5s cubic-bezier(.2,.9,.3,1.4);
}
@keyframes pop{from{transform:scale(.3)}}
/* 终端窗口 */
.term{position:absolute;inset:0;display:flex;flex-direction:column}
.term-bar{height:24px;background:#171c3a;display:flex;align-items:center;gap:6px;padding:0 10px;flex:none}
.term-bar i{width:9px;height:9px;border-radius:50%}
.term-bar i:nth-child(1){background:#ff5f57}
.term-bar i:nth-child(2){background:#febc2e}
.term-bar i:nth-child(3){background:#28c840}
.term-bar span{font-size:10px;color:var(--dim);margin-left:4px}
.term-body{
  flex:1;padding:10px;position:relative;overflow:hidden;
  font:10px/1.6 ui-monospace,Menlo,monospace;color:#c7d0f5;
  word-break:break-all;
}
.prompt{color:var(--ok)}
.logline{animation:ln .3s}
@keyframes ln{from{opacity:0;transform:translateY(4px)}}
.done{
  position:absolute;left:0;right:0;bottom:12px;text-align:center;
  font-size:22px;font-weight:800;color:var(--ok);
  opacity:0;transform:scale(.6);transition:.4s cubic-bezier(.2,.9,.3,1.3);
}
.done.show{opacity:1;transform:scale(1)}
.tmux-ok{margin-top:6px;color:var(--ok);opacity:0;transition:.3s}
.tmux-ok.show{opacity:1}
/* 项目卡片（框内迷你版） */
.pcard{
  position:relative;background:rgba(255,255,255,.05);border:1px solid var(--line);
  border-radius:14px;padding:10px 12px;margin-bottom:8px;
  opacity:0;transform:translateY(10px);transition:.45s;
}
.pcard.on{opacity:1;transform:none}
.pc-name{font-size:13px;font-weight:700}
.pc-sub{font-size:10.5px;color:var(--dim);margin-top:2px}
.pcard .dot{position:absolute;top:11px;right:11px}
.phone.sm .pcard{padding:8px 9px;border-radius:10px;margin-bottom:6px}
.phone.sm .pc-name{font-size:10px}
.phone.sm .pc-sub{font-size:8px}
/* 活性灯 */
.dot{width:10px;height:10px;border-radius:50%;display:inline-block;flex:none}
.dot.spin{background:conic-gradient(from 0deg,var(--g2),rgba(34,211,238,0) 68%);animation:rot 1s linear infinite}
.dot.breathe{background:var(--ok);animation:breathe 2.4s ease-in-out infinite}
.dot.gray{background:#5b6280}
.dot.none{background:transparent;border:2px dashed #3a4270}
@keyframes rot{to{transform:rotate(360deg)}}
@keyframes breathe{0%,100%{opacity:.22}50%{opacity:1}}
/* 手指圆点 */
.finger{
  position:absolute;right:14px;bottom:-9px;width:26px;height:26px;border-radius:50%;
  background:rgba(255,255,255,.88);box-shadow:0 0 0 5px rgba(255,255,255,.22);
  opacity:0;transition:opacity .3s,transform .18s;z-index:8;pointer-events:none;
}
.finger.show{opacity:1}
.finger.tap{transform:scale(.7)}
/* 现场画面（底部滑上） */
.live{
  position:absolute;left:0;right:0;bottom:0;height:76%;z-index:6;
  background:#10142e;border-top:1px solid var(--line);border-radius:18px 18px 0 0;
  transform:translateY(102%);transition:transform .5s cubic-bezier(.2,.8,.25,1);
}
.live.show{transform:none}
.live-head{padding:11px 14px;font-size:12.5px;font-weight:700;border-bottom:1px solid var(--line)}
.live-body{padding:12px 14px;font-size:11px}
.lv{margin-bottom:6px}
.lv.dim{color:var(--dim)}
/* 底部对话框 */
.chatbar{
  position:absolute;left:0;right:0;bottom:0;height:44px;z-index:7;
  background:#131834;border-top:1px solid var(--line);
  display:flex;align-items:center;gap:8px;padding:0 10px;
}
.chat-input{
  flex:1;height:30px;border-radius:15px;background:rgba(255,255,255,.06);
  border:1px solid var(--line);display:flex;align-items:center;
  padding:0 12px;font-size:11.5px;white-space:nowrap;overflow:hidden;
}
.send{
  height:30px;padding:0 14px;border-radius:15px;background:var(--grad);
  font-size:11.5px;font-weight:700;display:flex;align-items:center;transition:.2s;
}
.send.tap{transform:scale(.88)}
.bulb{
  width:30px;height:30px;border-radius:50%;flex:none;
  background:rgba(255,255,255,.06);border:1px solid var(--line);
  display:flex;align-items:center;justify-content:center;font-size:14px;
  position:relative;transition:.2s;
}
.bulb.glow{box-shadow:0 0 0 4px rgba(99,102,241,.45);transform:scale(1.14)}
.bulb .finger{right:-4px;bottom:-10px}
/* 聊天气泡 */
.msgs{
  position:absolute;inset:34px 0 44px;padding:12px;overflow:hidden;
  display:flex;flex-direction:column;gap:8px;justify-content:flex-end;
}
.msg{
  max-width:88%;padding:9px 12px;border-radius:14px;font-size:11.5px;line-height:1.6;
  opacity:0;transform:translateY(8px);transition:.4s;
}
.msg.show{opacity:1;transform:none}
.msg.me{align-self:flex-end;background:var(--grad);border-bottom-right-radius:4px}
.msg.bot{align-self:flex-start;background:rgba(255,255,255,.07);border:1px solid var(--line);border-bottom-left-radius:4px}
.typing{align-self:flex-start;font-size:10px;color:var(--dim);opacity:0;transition:.3s}
.typing.show{opacity:1}
/* 顶栏 + 铃铛 */
.topbar{display:flex;justify-content:space-between;align-items:center;margin-bottom:10px;font-size:13px;font-weight:700}
.bell{position:relative;font-size:18px;display:inline-block;transform-origin:top center}
.bell.ring{animation:shake 1s ease-in-out infinite}
@keyframes shake{
  0%,100%{transform:rotate(0)}
  10%{transform:rotate(16deg)}20%{transform:rotate(-13deg)}
  30%{transform:rotate(9deg)}40%{transform:rotate(-7deg)}
  50%{transform:rotate(4deg)}60%{transform:rotate(-2deg)}70%{transform:rotate(0)}
}
.badge{
  position:absolute;top:-4px;right:-7px;min-width:15px;height:15px;border-radius:8px;
  background:#ef4444;font-size:9px;display:flex;align-items:center;justify-content:center;
  padding:0 3px;opacity:0;transform:scale(.4);transition:.25s;
}
.badge.show{opacity:1;transform:scale(1)}
/* 汇报卡片（顶部滑入） */
.report-card{
  position:absolute;top:-100px;left:10px;right:10px;z-index:6;
  background:linear-gradient(135deg,#17352d,#131f3d);
  border:1px solid rgba(52,211,153,.55);border-radius:14px;padding:12px 14px;
  box-shadow:0 12px 32px rgba(0,0,0,.55);
  transition:top .55s cubic-bezier(.2,.9,.3,1.15),outline-color .3s;
  outline:2px solid transparent;
}
.report-card.show{top:64px}
.report-card.open{outline-color:rgba(52,211,153,.75)}
.rc-title{font-size:13px;font-weight:800}
.rc-sub{font-size:11px;color:var(--dim);margin-top:4px}
.report-card .finger{right:10px;bottom:-8px}
/* 小手机 toast */
.phone-toast{
  position:absolute;top:32px;left:8px;right:8px;z-index:6;
  background:#1c2348;border:1px solid var(--line);border-radius:10px;
  font-size:9.5px;padding:7px 9px;opacity:0;transform:translateY(-8px);transition:.35s;
}
.phone-toast.show{opacity:1;transform:none}

/* ---------- 9. 循环小动画 ---------- */
.loop-demo{position:relative}
/* 活性灯图例 */
.legend{padding:8px 16px}
.lg-row{display:flex;align-items:center;gap:12px;padding:11px 2px;font-size:14px;color:var(--dim);border-bottom:1px dashed var(--line)}
.lg-row:last-child{border-bottom:none}
.lg-row b{color:var(--tx);min-width:52px;font-size:14px}
/* 闹铃循环：铃响 → 手指点开 → 安静 → 再来 */
.alarm-stage{height:150px;display:flex;align-items:center;justify-content:center}
.loop-bell{font-size:46px;transform-origin:top center;animation:bellLoop 6s ease-in-out infinite}
.loop-badge{animation:badgeLoop 6s ease-in-out infinite}
.loop-finger{
  position:absolute;left:calc(50% + 26px);top:86px;width:30px;height:30px;border-radius:50%;
  background:rgba(255,255,255,.88);box-shadow:0 0 0 6px rgba(255,255,255,.22);
  animation:fingerLoop 6s ease-in-out infinite;opacity:0;
}
.alarm-msg{position:absolute;bottom:2px;left:0;right:0;text-align:center;font-size:12px;color:var(--dim)}
@keyframes bellLoop{
  0%,54%,100%{transform:rotate(0)}
  4%{transform:rotate(17deg)}8%{transform:rotate(-14deg)}12%{transform:rotate(11deg)}
  16%{transform:rotate(-8deg)}20%{transform:rotate(6deg)}24%{transform:rotate(-4deg)}
  28%{transform:rotate(2deg)}32%{transform:rotate(0)}
  36%{transform:rotate(13deg)}40%{transform:rotate(-10deg)}44%{transform:rotate(7deg)}
  48%{transform:rotate(-4deg)}52%{transform:rotate(0)}
}
@keyframes badgeLoop{
  0%,58%{opacity:1;transform:scale(1)}
  63%,90%{opacity:0;transform:scale(.4)}
  96%,100%{opacity:1;transform:scale(1)}
}
@keyframes fingerLoop{
  0%,48%{opacity:0;transform:scale(1)}
  54%{opacity:1;transform:scale(1)}
  60%{opacity:1;transform:scale(.72)}
  68%{opacity:1;transform:scale(1)}
  78%,100%{opacity:0;transform:scale(1)}
}
/* 朗读循环：高亮扫过 + 声波 */
.tts-msg{opacity:1;transform:none;position:relative;overflow:hidden;font-size:13px;padding:12px 14px}
.tts-hl{
  position:absolute;inset:0;
  background:linear-gradient(90deg,transparent,rgba(34,211,238,.18),transparent);
  transform:translateX(-100%);animation:sweep 2.8s ease-in-out infinite;
}
@keyframes sweep{55%,100%{transform:translateX(100%)}}
.spk{position:absolute;top:7px;right:9px;font-size:13px;animation:spk 2.8s ease-in-out infinite}
@keyframes spk{0%,100%{opacity:.45}8%,60%{opacity:1}}
.wave{display:flex;gap:4px;align-items:center;justify-content:center;height:38px;margin-top:10px}
.wave i{width:4px;border-radius:2px;background:var(--grad);animation:wv 1.1s ease-in-out infinite}
.wave i:nth-child(1){height:12px}
.wave i:nth-child(2){height:22px;animation-delay:.12s}
.wave i:nth-child(3){height:30px;animation-delay:.24s}
.wave i:nth-child(4){height:18px;animation-delay:.36s}
.wave i:nth-child(5){height:28px;animation-delay:.48s}
.wave i:nth-child(6){height:14px;animation-delay:.60s}
.wave i:nth-child(7){height:24px;animation-delay:.72s}
.wave i:nth-child(8){height:16px;animation-delay:.84s}
.wave i:nth-child(9){height:10px;animation-delay:.96s}
@keyframes wv{50%{transform:scaleY(.3)}}
/* 换班循环：两句气泡轮流出现 */
.shift-stage{display:flex;flex-direction:column;gap:10px;min-height:118px}
.loop-msg{animation:lm 8s ease-in-out infinite}
.loop-msg.b{animation-delay:1.8s}
@keyframes lm{
  0%{opacity:0;transform:translateY(8px)}
  7%,72%{opacity:1;transform:none}
  84%,100%{opacity:0;transform:translateY(-4px)}
}
/* 复制粘贴循环：选中扫过 → 已复制 → ⌘V */
.cp-line{
  font:12.5px ui-monospace,Menlo,monospace;background:#070a18;border-radius:10px;
  padding:12px;position:relative;overflow:hidden;color:#c7d0f5;
}
.cp-hl{
  position:absolute;top:0;bottom:0;left:12px;width:0;
  background:rgba(99,102,241,.40);border-radius:3px;
  animation:hl 6s ease-in-out infinite;
}
@keyframes hl{
  0%{width:0}
  22%,72%{width:calc(100% - 24px)}
  86%,100%{width:0}
}
.cp-toast{
  position:absolute;top:-12px;right:14px;background:var(--ok);color:#05231a;
  font-size:11px;font-weight:700;border-radius:8px;padding:4px 9px;
  opacity:0;animation:toast 6s ease-in-out infinite;
}
@keyframes toast{
  0%,24%{opacity:0;transform:translateY(4px)}
  31%,62%{opacity:1;transform:none}
  72%,100%{opacity:0}
}
.cp-keys{margin-top:14px;text-align:center;font-size:12px;color:var(--dim);opacity:0;animation:keys 6s ease-in-out infinite}
@keyframes keys{
  0%,40%{opacity:0}
  48%,76%{opacity:1}
  88%,100%{opacity:0}
}
kbd{background:#1c2348;border:1px solid var(--line);border-radius:6px;padding:2px 7px;font-family:inherit}
/* 终端页：迷你键盘 */
.mterm{background:#070a18;border-radius:12px;overflow:hidden;border:1px solid var(--line)}
.mterm-line{
  padding:10px 12px;border-bottom:1px solid var(--line);
  font:11px ui-monospace,Menlo,monospace;color:#c7d0f5;
}
.kb{display:grid;grid-template-columns:repeat(10,1fr);gap:4px;padding:8px;background:#10142e}
.kb span{
  background:#232a52;border-radius:5px;height:22px;
  display:flex;align-items:center;justify-content:center;
  font-size:9px;color:var(--dim);font-family:ui-monospace,Menlo,monospace;
}
/* APP 下载卡 */
.app-card{display:flex;gap:12px;align-items:center;flex-wrap:wrap}
.app-ic{
  width:46px;height:46px;border-radius:12px;background:var(--grad);flex:none;
  display:flex;align-items:center;justify-content:center;font-size:24px;
}
.app-tx{flex:1;min-width:180px;font-size:14px}
.app-tx p{font-size:12px;color:var(--dim);margin-top:4px}
.app-card .btn{padding:11px 18px;font-size:14px;margin-left:auto}

/* ---------- 10. FAQ ---------- */
.faq-list{margin-top:24px}
details{background:var(--card);border:1px solid var(--line);border-radius:14px;margin-bottom:10px;overflow:hidden}
summary{
  padding:16px 18px;font-size:16px;font-weight:700;cursor:pointer;list-style:none;
  display:flex;justify-content:space-between;align-items:center;gap:10px;
}
summary::-webkit-details-marker{display:none}
summary::after{content:'＋';color:var(--g2);font-size:19px;transition:.3s;flex:none}
details[open] summary::after{transform:rotate(45deg)}
details p{padding:0 18px 16px;color:var(--dim);font-size:14.5px;line-height:1.75}

/* ---------- 11. 页脚 ---------- */
footer{text-align:center;padding:52px 0 calc(44px + env(safe-area-inset-bottom))}
.flogo{width:44px}
.flinks{display:flex;flex-direction:column;gap:12px;margin:20px 0 24px}
.flinks a{
  color:var(--tx);text-decoration:none;background:var(--card);
  border:1px solid var(--line);border-radius:12px;padding:14px;font-size:15px;font-weight:600;
}
.flinks a:active{border-color:var(--g2)}
.slogan{color:var(--dim);font-size:13px}

/* ---------- 12. 入场动画与无障碍 ---------- */
.reveal{opacity:0;transform:translateY(24px);transition:opacity .7s ease,transform .7s ease}
.reveal.in{opacity:1;transform:none}
@media(min-width:720px){
  .hero h1{font-size:34px}
  h2{font-size:30px}
}
@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.01s !important;animation-iteration-count:1 !important;transition-duration:.01s !important}
  html{scroll-behavior:auto}
}