/* ============================================================
   qskybet — Product Portal (纯静态)
   深色科技风设计系统
   Palette: #050010 bg · #9333EA/#7C3AED accent · #38BDF8 sky (logo) · #A8A8C2 secondary
   ============================================================ */

:root {
  /* Colors */
  --bg: #050010;
  --bg-elev: #0A0518;
  --bg-card: rgba(255, 255, 255, 0.03);
  --bg-card-hover: rgba(255, 255, 255, 0.05);
  --hairline: rgba(255, 255, 255, 0.08);
  --hairline-strong: rgba(147, 51, 234, 0.35);
  --accent: #9333EA;
  --accent-2: #7C3AED;
  --accent-soft: #C084FC;
  --accent-dim: rgba(147, 51, 234, 0.12);
  --text: #F5F3FF;
  --text-2: #A8A8C2;
  --text-3: #6E6A8A;
  --green: #22C55E;
  --green-dim: rgba(34, 197, 94, 0.14);
  --red: #EF4444;
  --red-dim: rgba(239, 68, 68, 0.14);
  --amber: #F59E0B;
  --amber-dim: rgba(245, 158, 11, 0.14);

  /* Layout */
  --radius: 16px;
  --radius-sm: 12px;
  --maxw: 1160px;
  --sect-pad: clamp(72px, 9vw, 120px);
  --ease: cubic-bezier(.22, .61, .36, 1);

  /* Chat：气泡最大宽度（移动端断点内会放宽） */
  --chat-bubble-max: 82%;
}

/* ---------- Base ---------- */
html { scroll-behavior: smooth; scroll-padding-top: 84px; }
body {
  font-family: Inter, 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
::selection { background: rgba(147, 51, 234, .4); color: #fff; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--accent-soft); outline-offset: 2px; border-radius: 6px; }

/* Scrollbar */
::-webkit-scrollbar { width: 11px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: #2b2140; border-radius: 8px; }
::-webkit-scrollbar-thumb:hover { background: #3a2d55; }

/* ---------- Layout helpers ---------- */
.wrap { width: min(var(--maxw), 90%); margin: 0 auto; position: relative; z-index: 2; }
.center { text-align: center; }
.section { position: relative; padding: var(--sect-pad) 0; }
.section-alt { background: linear-gradient(180deg, rgba(147,51,234,.05), transparent 40%); }

.section-title {
  font-size: clamp(28px, 3.6vw, 44px);
  font-weight: 700;
  letter-spacing: -.03em;
  margin: 20px 0 14px;
  background: linear-gradient(180deg, #fff 30%, #C4B5FD 110%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.section-sub { color: var(--text-2); font-size: clamp(15px, 1.5vw, 18px); max-width: 620px; margin: 0 auto 56px; }

/* ---------- Header ---------- */
.site-header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  padding: 16px 0;
  transition: background .3s var(--ease), padding .3s var(--ease), border-color .3s;
  border-bottom: 1px solid transparent;
}
.site-header.scrolled {
  background: rgba(5, 0, 16, .82);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom-color: var(--hairline);
  padding: 10px 0;
}
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: center; }
.brand-logo { height: 38px; width: auto; }
.main-nav { display: flex; gap: 34px; }
.nav-link { font-size: 15px; color: var(--text-2); font-weight: 500; transition: color .2s; }
.nav-link:hover { color: var(--text); }
.header-actions { display: flex; align-items: center; gap: 14px; }
.btn-sm { padding: .62em 1.2em; font-size: 14px; border-radius: 10px; }
.menu-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 8px; }
.menu-toggle span { width: 24px; height: 2px; background: var(--text); border-radius: 2px; transition: transform .3s, opacity .3s; }
.menu-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle.open span:nth-child(2) { opacity: 0; }
.menu-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Language switch ---------- */
.lang-switch {
  display: inline-flex; align-items: center; gap: 2px;
  padding: 4px; border-radius: 10px;
  background: rgba(255,255,255,.04); border: 1px solid rgba(255,255,255,.08);
  font-size: 13px; font-weight: 600;
}
.lang-switch a {
  display: inline-flex; align-items: center; justify-content: center;
  min-width: 34px; padding: 6px 10px; border-radius: 7px;
  color: var(--text-2); letter-spacing: .02em;
  transition: color .2s, background .2s;
}
.lang-switch a.active {
  color: #fff;
  background: linear-gradient(135deg, #9333EA, #7C3AED);
  box-shadow: 0 4px 14px rgba(124,58,237,.4);
}
.lang-switch a:not(.active):hover { color: #fff; background: rgba(255,255,255,.05); }

/* ---------- Hero ---------- */
.hero { background: var(--bg); }
.hero-content { text-align: center; }
.hero-title .grad { background: none; }
.halo {
  position: absolute; border-radius: 50%; filter: blur(80px); pointer-events: none; z-index: 1;
}
.halo-1 { width: 620px; height: 620px; top: -180px; left: 50%; transform: translateX(-50%); background: radial-gradient(circle, rgba(147,51,234,.35), transparent 65%); }
.halo-2 { width: 420px; height: 420px; top: 140px; left: 16%; background: radial-gradient(circle, rgba(124,58,237,.22), transparent 60%); }
.grid-mesh {
  position: absolute; inset: 0; z-index: 1; pointer-events: none;
  background-image: linear-gradient(rgba(255,255,255,.04) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.04) 1px, transparent 1px);
  background-size: 72px 72px;
  -webkit-mask-image: radial-gradient(circle at 50% 30%, #000 30%, transparent 72%);
  mask-image: radial-gradient(circle at 50% 30%, #000 30%, transparent 72%);
}

/* ---------- Buttons ---------- */
.btn { position: relative; overflow: hidden; }

/* ---------- Product Mockup (CSS admin skeleton) ---------- */
.mockup {
  max-width: 960px; margin: 56px auto 0; border-radius: 18px;
  border: 1px solid var(--hairline);
  background: linear-gradient(180deg, rgba(20,12,42,.9), rgba(10,5,24,.95));
  box-shadow: 0 30px 80px rgba(0,0,0,.55), 0 0 0 1px rgba(147,51,234,.08);
  text-align: left; overflow: hidden;
}
.mock-titlebar { display: flex; align-items: center; gap: 8px; padding: 14px 18px; border-bottom: 1px solid var(--hairline); background: rgba(255,255,255,.02); }
.mock-titlebar .dot { width: 12px; height: 12px; border-radius: 50%; }
.dot.red { background: #FF5F57; } .dot.yellow { background: #FEBC2E; } .dot.green { background: #28C840; }
.mock-title { margin-left: 12px; font-size: 13px; color: var(--text-3); }
.mock-body { display: grid; grid-template-columns: 200px 1fr; min-height: 320px; }
.mock-side { padding: 18px 12px; border-right: 1px solid var(--hairline); background: rgba(0,0,0,.15); }
.mock-nav { padding: 11px 14px; border-radius: 10px; font-size: 14px; color: var(--text-2); cursor: default; margin-bottom: 4px; }
.mock-nav:hover { background: rgba(255,255,255,.03); color: var(--text); }
.mock-nav.active { background: var(--accent-dim); color: var(--accent-soft); font-weight: 600; }
.mock-main { padding: 22px; display: flex; flex-direction: column; gap: 18px; }
.mock-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.mock-stat { padding: 16px; background: var(--bg-card); border: 1px solid var(--hairline); border-radius: 14px; }
.m-label { display: block; font-size: 12.5px; color: var(--text-3); }
.m-value { display: block; font-size: 26px; font-weight: 700; margin: 6px 0 2px; letter-spacing: -.02em; }
.m-trend { font-size: 12px; font-weight: 600; }
.m-trend.up { color: var(--green); } .m-trend.flat { color: var(--text-3); }
.mock-table { border: 1px solid var(--hairline); border-radius: 12px; overflow: hidden; }
.mock-table-head, .mock-row { display: grid; grid-template-columns: 1.4fr .8fr 1.2fr 1fr 1fr; gap: 10px; padding: 12px 16px; font-size: 13.5px; align-items: center; }
.mock-table-head { background: rgba(255,255,255,.02); color: var(--text-3); border-bottom: 1px solid var(--hairline); }
.mock-row { border-bottom: 1px solid rgba(255,255,255,.04); color: var(--text-2); }
.mock-row:last-child { border-bottom: none; }
.chip { display: inline-block; padding: 3px 10px; border-radius: 999px; font-size: 12px; background: rgba(147,51,234,.14); color: var(--accent-soft); width: fit-content; }
.status { font-size: 12px; font-weight: 600; }
.status.ok { color: var(--green); } .status.warn { color: var(--amber); }

/* ---------- Cards grid ---------- */
.grid { display: grid; gap: 22px; }
.cards-3 { grid-template-columns: repeat(3, 1fr); margin-top: 12px; }
.cards-4 { grid-template-columns: repeat(4, 1fr); margin-top: 12px; }
.card {
  padding: 30px 26px; border-radius: var(--radius);
  background: var(--bg-card); border: 1px solid var(--hairline);
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
  transition: transform .3s var(--ease), border-color .3s, background .3s;
}
.card:hover { transform: translateY(-4px); border-color: var(--hairline-strong); background: var(--bg-card-hover); }
.card-icon { font-size: 30px; margin-bottom: 16px; }
.card h3 { font-size: 19px; font-weight: 600; margin-bottom: 10px; letter-spacing: -.02em; }
.card p { color: var(--text-2); font-size: 14.5px; line-height: 1.65; }

.cap-card {
  padding: 26px 22px; border-radius: var(--radius);
  background: linear-gradient(180deg, var(--bg-card), rgba(255,255,255,.01));
  border: 1px solid var(--hairline);
  position: relative; overflow: hidden;
  transition: transform .3s var(--ease), border-color .3s;
}
.cap-card:hover { transform: translateY(-4px); border-color: var(--hairline-strong); }
.cap-num { font-size: 13px; font-weight: 700; color: var(--accent-soft); letter-spacing: .08em; }
.cap-card h3 { font-size: 17px; font-weight: 600; margin: 12px 0 8px; }
.cap-card p { color: var(--text-2); font-size: 14px; line-height: 1.6; }

/* ---------- Screenshots (CSS skeleton) ---------- */
.shots { margin-top: 12px; }
.shot-card { margin: 0; padding: 0; border-radius: var(--radius); overflow: hidden; border: 1px solid var(--hairline); background: var(--bg-card); transition: transform .3s var(--ease), border-color .3s; }
.shot-card:hover { transform: translateY(-4px); border-color: var(--hairline-strong); }
.shot-bar { padding: 13px 16px; background: rgba(255,255,255,.02); border-bottom: 1px solid var(--hairline); font-size: 13.5px; font-weight: 600; color: var(--text-2); }
.shot-canvas { padding: 20px; min-height: 168px; display: flex; flex-direction: column; gap: 10px; }
.shot-pill { padding: 11px 14px; border-radius: 10px; font-size: 13.5px; background: rgba(255,255,255,.03); border: 1px solid rgba(255,255,255,.06); color: var(--text-2); }
.shot-pill.active { background: var(--accent-dim); border-color: var(--hairline-strong); color: var(--accent-soft); font-weight: 600; }
.shot-canvas.s2 { justify-content: center; }
.mini-chart { height: 74px; border-radius: 10px; background: linear-gradient(180deg, rgba(147,51,234,.18), transparent); border: 1px solid var(--hairline); position: relative; }
.mini-chart::after { content: ''; position: absolute; inset: 0; background: linear-gradient(90deg, transparent 60%, rgba(34,197,94,.25)); clip-path: polygon(0 65%, 20% 45%, 45% 70%, 70% 30%, 100% 50%, 100% 100%, 0 100%); }
.shot-kv { display: flex; justify-content: space-between; align-items: center; font-size: 13px; color: var(--text-3); }
.shot-kv b { color: var(--text); font-size: 16px; font-weight: 700; }
.shot-kv b.up { color: var(--green); }
.shot-log { padding: 10px 13px; border-radius: 9px; font-size: 12.5px; background: rgba(255,255,255,.02); border: 1px solid rgba(255,255,255,.05); color: var(--text-2); font-family: 'JetBrains Mono', 'Consolas', monospace; }
.shot-log.ok { border-left: 3px solid var(--green); }
.shot-log.warn { border-left: 3px solid var(--amber); color: var(--text-2); }
.shot-card figcaption { padding: 12px 16px; border-top: 1px solid var(--hairline); font-size: 13px; color: var(--text-3); }

/* ---------- Download ---------- */
.download-bg { background: radial-gradient(circle at 50% 30%, rgba(124,58,237,.22), transparent 60%), var(--bg); }
.download-inner { display: grid; grid-template-columns: 1.1fr .9fr; gap: 48px; align-items: center; }
.dl-sub { color: var(--text-2); font-size: 16px; margin-bottom: 24px; }
.dl-points { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 12px; }
.dl-points li { color: var(--text-2); font-size: 15px; }
.dl-card { padding: 34px 30px; border-radius: 20px; background: linear-gradient(180deg, var(--bg-card), rgba(255,255,255,.015)); border: 1px solid var(--hairline); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); box-shadow: 0 24px 60px rgba(0,0,0,.4); }
.dl-ver { display: flex; align-items: center; justify-content: space-between; margin-bottom: 8px; }
.dl-name { font-size: 22px; font-weight: 700; letter-spacing: -.02em; }
.dl-ver-tag { font-size: 13px; padding: 5px 12px; border-radius: 999px; background: var(--accent-dim); color: var(--accent-soft); font-weight: 600; }
.dl-size { color: var(--text-3); font-size: 13.5px; margin-bottom: 24px; }
.btn-block { width: 100%; padding: 1.05em; font-size: 16px; }
.dl-note { margin-top: 14px; font-size: 13px; color: var(--text-3); text-align: center; min-height: 20px; }

/* ---------- Contact ---------- */
.contact-grid { display: grid; grid-template-columns: .9fr 1.1fr; gap: 48px; margin-top: 12px; align-items: start; }
.contact-info { display: flex; flex-direction: column; gap: 22px; }
.ci-item { display: flex; gap: 16px; align-items: flex-start; padding: 18px; border-radius: var(--radius); background: var(--bg-card); border: 1px solid var(--hairline); }
.ci-ico { font-size: 22px; line-height: 1; }
.ci-item b { font-size: 15px; font-weight: 600; display: block; margin-bottom: 4px; }
.ci-item p { color: var(--text-2); font-size: 14px; margin: 0; }
.contact-form { display: flex; flex-direction: column; gap: 18px; padding: 28px; border-radius: var(--radius); background: var(--bg-card); border: 1px solid var(--hairline); }
.contact-form label { display: flex; flex-direction: column; gap: 8px; font-size: 14px; font-weight: 500; color: var(--text-2); }
.contact-form input, .contact-form textarea {
  background: rgba(0,0,0,.25); border: 1px solid var(--hairline); border-radius: 10px;
  padding: 12px 14px; color: var(--text); font-size: 14.5px; font-family: inherit; font-weight: 400;
  transition: border-color .2s, box-shadow .2s; resize: vertical;
}
.contact-form input:focus, .contact-form textarea:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(147,51,234,.18); }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form-status { min-height: 20px; font-size: 14px; text-align: center; font-weight: 500; }
.form-status.ok { color: var(--green); } .form-status.err { color: var(--red); }

/* ---------- Floating Live Chat / Message Board ---------- */
.chat-fab {
  position: fixed; right: 22px; bottom: 22px; z-index: 1000;
  width: 56px; height: 56px; border-radius: 50%; border: none; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg,#9333EA,#7C3AED); color: #fff;
  box-shadow: 0 10px 30px rgba(124,58,237,.45);
  transition: transform .2s var(--ease), box-shadow .2s var(--ease);
}
.chat-fab:hover { transform: translateY(-3px); box-shadow: 0 14px 40px rgba(124,58,237,.6); }
.chat-fab:active { transform: scale(.94); }

.chat-panel {
  position: fixed; right: 22px; bottom: 90px; z-index: 999;
  width: min(380px, calc(100vw - 32px));
  height: min(520px, calc(100vh - 120px));
  display: flex; flex-direction: column;
  background: #0A0518; border: 1px solid var(--hairline-strong);
  border-radius: var(--radius); box-shadow: 0 24px 60px rgba(0,0,0,.55);
  overflow: hidden; animation: chatIn .28s var(--ease);
}
/* 关键：作者样式 display:flex 会覆盖 UA 的 [hidden]{display:none}，必须显式兜底 */
.chat-panel[hidden] { display: none; }
@keyframes chatIn { from { opacity: 0; transform: translateY(14px) scale(.98); } to { opacity: 1; transform: none; } }

.chat-panel-head {
  display: flex; align-items: center; gap: 10px; flex-shrink: 0;
  padding: 14px 16px; border-bottom: 1px solid var(--hairline);
  background: rgba(147,51,234,.08);
}
.chat-panel-title { flex: 1; font-size: 15px; font-weight: 600; letter-spacing: -.01em; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.chat-status { display: inline-flex; align-items: center; gap: 6px; font-size: 12px; color: var(--text-2); padding: 4px 10px; border-radius: 999px; background: rgba(255,255,255,.04); border: 1px solid var(--hairline); white-space: nowrap; }
.chat-status .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--text-3); }
.chat-status.online .dot { background: var(--green); box-shadow: 0 0 0 3px var(--green-dim); }
.chat-status.offline .dot { background: var(--red); box-shadow: 0 0 0 3px var(--red-dim); }
.chat-status.connecting .dot { background: var(--amber); box-shadow: 0 0 0 3px var(--amber-dim); animation: chatPulse 1.2s var(--ease) infinite; }
@keyframes chatPulse { 0%,100% { opacity: 1; } 50% { opacity: .35; } }
.chat-close {
  width: 30px; height: 30px; border-radius: 50%; border: none; cursor: pointer;
  background: rgba(255,255,255,.06); color: var(--text-2); font-size: 20px; line-height: 1;
  display: flex; align-items: center; justify-content: center; flex-shrink: 0;
  transition: background .2s, color .2s;
}
.chat-close:hover { background: rgba(255,255,255,.14); color: var(--text); }

.chat-list {
  flex: 1; min-height: 0; overflow-y: auto; padding: 12px;
  background: rgba(0,0,0,.22);
  display: flex; flex-direction: column; align-items: stretch; gap: 10px;
}

/* 一行消息：靠左 / 靠右由 align-self 决定，自顶向下排列（column flex 的主轴）。
   默认（官方客服 + 其他访客）一律靠左；只有自己发的 .self 靠右。
   这里显式写 align-self 而不是依赖「max-width + stretch」的隐式行为，
   避免以后任何人改 .chat-list 的 align-items 时整排气泡位置跑偏。 */
.chat-msg {
  display: flex; flex-direction: column; align-items: flex-start; gap: 2px;
  align-self: flex-start; max-width: var(--chat-bubble-max); min-width: 0;
}
.chat-msg .who { font-size: 12px; font-weight: 600; color: var(--text-3); padding-left: 4px; }
.chat-msg .body {
  background: rgba(255,255,255,.05); border: 1px solid var(--hairline);
  padding: 8px 13px; border-radius: 4px 14px 14px 14px; color: var(--text); font-size: 14px;
  word-break: break-word; overflow-wrap: anywhere; /* 长 URL / 无空格长串不撑破气泡 */
}
.chat-msg .when { font-size: 11px; color: var(--text-3); padding-left: 4px; }

/* 自己发的：整行靠右，气泡紫渐变、右上角收尖 */
.chat-msg.self { align-self: flex-end; align-items: flex-end; }
.chat-msg.self .who { color: var(--accent-soft); padding-left: 0; padding-right: 4px; }
.chat-msg.self .body { background: linear-gradient(135deg,#9333EA,#7C3AED); border-color: transparent; border-radius: 14px 4px 14px 14px; color: #fff; }
.chat-msg.self .when { padding-left: 0; padding-right: 4px; }

/* 系统提示（欢迎语 / 连接状态 / 空态）：居中通栏 */
.chat-msg.system { align-self: center; align-items: center; max-width: 100%; text-align: center; }
.chat-msg.system .body, .chat-msg.system { background: transparent; border: none; color: var(--text-3); font-size: 12px; padding: 2px 0; }

/* 客服 / 官方回复：区别于普通访客，带「官方」徽标 + 冷色气泡 */
.chat-msg.agent .who { color: var(--green, #22C55E); }
.chat-msg.agent .tag {
  display: inline-block; margin-right: 5px; padding: 1px 6px;
  font-size: 10px; font-weight: 700; letter-spacing: .02em;
  color: #052e16; background: var(--green, #22C55E); border-radius: 4px;
  vertical-align: 1px;
}
.chat-msg.agent .body {
  background: rgba(34,197,94,.12);
  border-color: rgba(34,197,94,.28);
}

.chat-input { display: grid; grid-template-columns: 1fr auto; gap: 10px; padding: 12px; border-top: 1px solid var(--hairline); flex-shrink: 0; }
.chat-input input {
  background: rgba(0,0,0,.25); border: 1px solid var(--hairline); border-radius: 10px;
  padding: 11px 14px; color: var(--text); font-size: 14px; font-family: inherit; font-weight: 400;
  transition: border-color .2s, box-shadow .2s; width: 100%;
}
.chat-input input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(147,51,234,.18); }
.chat-input .btn { height: 44px; padding: 0 18px; font-size: 14px; }
.chat-hint { min-height: 18px; font-size: 12.5px; text-align: center; font-weight: 500; margin: 8px 12px 10px; color: var(--text-2); flex-shrink: 0; }
.chat-hint .ok { color: var(--green); }
.chat-hint .err { color: var(--red); }

/* ---------- Footer ---------- */
.site-footer { border-top: 1px solid var(--hairline); padding: 56px 0 40px; background: rgba(0,0,0,.2); }
.footer-inner { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 40px; align-items: start; }
.footer-brand p { color: var(--text-3); font-size: 14px; margin-top: 14px; }
.footer-nav { display: flex; flex-direction: column; gap: 12px; }
.footer-nav a { color: var(--text-2); font-size: 14.5px; transition: color .2s; }
.footer-nav a:hover { color: var(--text); }
.footer-legal { text-align: right; }
.footer-legal p { color: var(--text-3); font-size: 13.5px; margin-bottom: 8px; }
.footer-safe { opacity: .8; }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 900px) {
  .main-nav {
    position: fixed; top: 64px; right: 5%; z-index: 99;
    flex-direction: column; gap: 0; min-width: 200px;
    background: rgba(10, 5, 24, .97); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--hairline); border-radius: 16px; padding: 10px;
    opacity: 0; transform: translateY(-8px); pointer-events: none; transition: opacity .25s, transform .25s;
  }
  .main-nav.open { opacity: 1; transform: translateY(0); pointer-events: auto; }
  .main-nav .nav-link { padding: 13px 16px; border-radius: 10px; }
  .main-nav .nav-link:hover { background: rgba(255,255,255,.04); }
  .menu-toggle { display: flex; }
  .cards-3 { grid-template-columns: 1fr; }
  .cards-4 { grid-template-columns: 1fr 1fr; }
  .download-inner { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; gap: 28px; }
  .footer-legal { text-align: left; }
  .mock-body { grid-template-columns: 1fr; }
  .mock-side { display: none; }
}
@media (max-width: 560px) {
  .cards-4 { grid-template-columns: 1fr; }
  .mock-stats { grid-template-columns: 1fr; }
  .mock-table-head, .mock-row { grid-template-columns: 1fr 1fr; font-size: 12.5px; }
  .form-row { grid-template-columns: 1fr; }
  .btn-row { flex-direction: column; width: 100%; }
  .btn-row .btn { width: 100%; }
  .lang-switch { font-size: 12px; }
  .lang-switch a { min-width: 30px; padding: 5px 8px; }
  .chat-fab { right: 12px; bottom: 12px; width: 50px; height: 50px; }
  /* 用 left+right 定位而不是 100vw：100vw 含滚动条宽度，移动端会溢出 4~8px */
  .chat-panel {
    left: 8px; right: 8px; bottom: 74px; width: auto;
    height: min(520px, calc(100vh - 100px));
    --chat-bubble-max: 86%; /* 面板变窄，气泡相应放宽，避免文字被压成竖条 */
  }
  /* 现代浏览器：dvh 随地址栏/软键盘实时变化，避免输入框被顶出可视区 */
  @supports (height: 100dvh) {
    .chat-panel { height: min(520px, calc(100dvh - 100px)); }
  }
  .chat-msg .body { font-size: 13.5px; padding: 7px 12px; }
  .chat-input { padding: 10px; gap: 8px; }
  .chat-input .btn { padding: 0 14px; }
}

/* ============================================================
   Motion (respect prefers-reduced-motion)
   ============================================================ */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.visible { opacity: 1; transform: translateY(0); }
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; }
}