/* ==========================================================================
   智能客服系统 · 官网样式
   纯手写 CSS，无框架、无构建步骤。设计语言参考主流 SaaS 落地页：
   浅色渐变背景 + 玻璃拟态卡片 + 柔和阴影。
   ========================================================================== */

:root {
  /* 主色调：蓝紫渐变，比纯蓝更有科技感，也和截图里的后台蓝呼应 */
  --brand: #4f46e5;
  --brand-light: #6366f1;
  --brand-dark: #4338ca;
  --accent: #ec4899;
  --accent-warm: #f59e0b;

  --ink: #0f172a;
  --ink-soft: #475569;
  --ink-mute: #94a3b8;

  --bg: #ffffff;
  --bg-soft: #f8fafc;
  --bg-tint: #f1f5f9;
  --line: #e2e8f0;

  --radius: 16px;
  --radius-sm: 10px;
  --radius-lg: 24px;

  --shadow-sm: 0 1px 3px rgba(15, 23, 42, .06), 0 1px 2px rgba(15, 23, 42, .04);
  --shadow: 0 4px 20px rgba(15, 23, 42, .07);
  --shadow-lg: 0 20px 60px rgba(15, 23, 42, .12);
  --shadow-brand: 0 10px 40px rgba(79, 70, 229, .25);

  --max-w: 1180px;
  --nav-h: 68px;
}

/* 深色模式：跟随系统，也可用导航栏按钮手动切换 */
[data-theme="dark"] {
  --ink: #f1f5f9;
  --ink-soft: #cbd5e1;
  --ink-mute: #94a3b8;
  --bg: #0b1120;
  --bg-soft: #111827;
  --bg-tint: #1e293b;
  --line: #1e293b;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, .3);
  --shadow: 0 4px 20px rgba(0, 0, 0, .35);
  --shadow-lg: 0 20px 60px rgba(0, 0, 0, .5);
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  /* 锚点跳转时给固定导航栏留出空间，否则标题会被遮住 */
  scroll-padding-top: calc(var(--nav-h) + 20px);
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
               "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: var(--brand); text-decoration: none; transition: color .2s; }
a:hover { color: var(--brand-dark); }

.wrap { max-width: var(--max-w); margin: 0 auto; padding: 0 24px; }

/* ─── 导航栏 ────────────────────────────────────────────── */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  height: var(--nav-h);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color .25s, box-shadow .25s;
}
.nav.scrolled { border-bottom-color: var(--line); box-shadow: var(--shadow-sm); }
.nav-inner {
  max-width: var(--max-w); margin: 0 auto; padding: 0 24px; height: 100%;
  display: flex; align-items: center; gap: 28px;
}

.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 17px; color: var(--ink); flex-shrink: 0; }
.logo:hover { color: var(--ink); }
.logo-mark {
  width: 34px; height: 34px; border-radius: 9px;
  background: linear-gradient(135deg, var(--brand), var(--accent));
  display: grid; place-items: center; color: #fff; font-size: 17px;
  box-shadow: 0 4px 14px rgba(79, 70, 229, .35);
}

.nav-links { display: flex; gap: 4px; margin-left: 8px; flex: 1; }
.nav-links a {
  padding: 8px 14px; border-radius: 8px; font-size: 14.5px;
  color: var(--ink-soft); font-weight: 500; position: relative;
}
.nav-links a:hover { color: var(--brand); background: var(--bg-tint); }
.nav-links a.active { color: var(--brand); font-weight: 600; }
.nav-badge {
  display: inline-block; margin-left: 5px; padding: 1px 6px;
  font-size: 10px; font-weight: 700; line-height: 1.5;
  border-radius: 5px; color: #fff; vertical-align: 2px;
  background: linear-gradient(135deg, var(--accent), #f43f5e);
}

.nav-right { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.icon-btn {
  width: 36px; height: 36px; border-radius: 9px; border: 1px solid var(--line);
  background: var(--bg); color: var(--ink-soft); cursor: pointer;
  display: grid; place-items: center; font-size: 15px;
  transition: border-color .2s, color .2s, transform .15s;
}
.icon-btn:hover { border-color: var(--brand); color: var(--brand); }
.icon-btn:active { transform: scale(.94); }
.lang-btn { font-weight: 700; font-size: 13px; letter-spacing: .3px; }

.nav-toggle { display: none; }

/* ─── 按钮 ──────────────────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 24px; border-radius: 11px; border: 1px solid transparent;
  font-size: 15px; font-weight: 600; font-family: inherit;
  cursor: pointer; white-space: nowrap;
  transition: transform .15s, box-shadow .25s, background .2s, border-color .2s;
}
.btn:active { transform: translateY(1px); }
.btn-primary {
  background: linear-gradient(135deg, var(--brand), var(--brand-light));
  color: #fff; box-shadow: var(--shadow-brand);
}
.btn-primary:hover { color: #fff; box-shadow: 0 14px 44px rgba(79, 70, 229, .38); transform: translateY(-2px); }
.btn-ghost { background: var(--bg); color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--brand); color: var(--brand); transform: translateY(-2px); }
.btn-lg { padding: 15px 32px; font-size: 16px; border-radius: 13px; }
.btn-sm { padding: 8px 16px; font-size: 13.5px; border-radius: 9px; }

/* ─── Hero ──────────────────────────────────────────────── */
.hero {
  position: relative; padding: calc(var(--nav-h) + 56px) 0 72px;
  overflow: hidden;
}
/* 背景光斑：用两个大半径径向渐变模拟柔光，比纯色背景有层次 */
.hero::before {
  content: ""; position: absolute; inset: 0; z-index: -1;
  background:
    radial-gradient(58% 48% at 12% 8%, rgba(99, 102, 241, .16), transparent 70%),
    radial-gradient(52% 44% at 88% 16%, rgba(236, 72, 153, .13), transparent 70%),
    radial-gradient(46% 40% at 62% 92%, rgba(56, 189, 248, .12), transparent 70%);
}
[data-theme="dark"] .hero::before {
  background:
    radial-gradient(58% 48% at 12% 8%, rgba(99, 102, 241, .22), transparent 70%),
    radial-gradient(52% 44% at 88% 16%, rgba(236, 72, 153, .16), transparent 70%);
}

.hero-grid {
  display: grid; grid-template-columns: 1fr 1.08fr; gap: 56px; align-items: center;
}

.pill {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 14px 6px 8px; border-radius: 999px;
  background: color-mix(in srgb, var(--bg) 70%, transparent);
  border: 1px solid var(--line); box-shadow: var(--shadow-sm);
  font-size: 13px; font-weight: 600; color: var(--brand);
  margin-bottom: 22px;
}
.pill-dot {
  width: 22px; height: 22px; border-radius: 50%;
  background: linear-gradient(135deg, var(--brand), var(--accent));
  display: grid; place-items: center; color: #fff; font-size: 11px;
}

.hero h1 {
  font-size: clamp(34px, 4.6vw, 56px); line-height: 1.18;
  margin: 0 0 20px; letter-spacing: -1.2px; font-weight: 800;
}
.grad {
  background: linear-gradient(120deg, var(--brand) 5%, var(--accent) 55%, var(--accent-warm) 95%);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}
.hero-sub {
  font-size: 17px; color: var(--ink-soft); margin: 0 0 26px; max-width: 520px;
}
.hero-sub b { color: var(--ink); font-weight: 600; }

.hero-tags { display: flex; flex-wrap: wrap; gap: 20px; margin-bottom: 32px; }
.hero-tags span { display: inline-flex; align-items: center; gap: 7px; font-size: 14px; color: var(--ink-soft); font-weight: 500; }
.hero-tags i { font-style: normal; font-size: 15px; }

.hero-cta { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 26px; }

.hero-meta { display: flex; flex-wrap: wrap; gap: 22px; font-size: 13.5px; color: var(--ink-mute); }
.hero-meta span { display: inline-flex; align-items: center; gap: 6px; }

/* Hero 右侧：截图叠放
   主截图只显示上半部分（模型配置表单），底部一大片空白用 max-height 裁掉；
   悬浮的客服窗按比例放右下角，高度和主图错开，避免被裁。*/
.shots { position: relative; }
.shot {
  border-radius: 14px; overflow: hidden;
  border: 1px solid var(--line); background: var(--bg);
  box-shadow: var(--shadow-lg);
}
.shot-main {
  transform: perspective(1400px) rotateY(-6deg) rotateX(2deg);
  max-height: 340px;
}
.shot-main img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top;
}
.shot-float {
  position: absolute; right: -48px; bottom: -30px;
  width: 86%;
  max-width: 560px;
  aspect-ratio: 16 / 10;
  border-radius: 16px; overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: 0 28px 70px rgba(15, 23, 42, .28);
  animation: float 5.5s ease-in-out infinite;
}
.shot-float img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center right;
}
.shot-float img { width: 100%; display: block; }
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-12px); }
}
@media (prefers-reduced-motion: reduce) {
  .shot-float { animation: none; }
  html { scroll-behavior: auto; }
}

/* ─── 数据条 ────────────────────────────────────────────── */
.stats {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px;
  background: var(--line); border: 1px solid var(--line);
  border-radius: var(--radius); overflow: hidden; margin-top: 72px;
}
.stat { background: var(--bg); padding: 26px 20px; text-align: center; }
.stat-n {
  font-size: 30px; font-weight: 800; letter-spacing: -1px;
  background: linear-gradient(135deg, var(--brand), var(--accent));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.stat-l { font-size: 13px; color: var(--ink-mute); margin-top: 4px; }

/* ─── 区块通用 ──────────────────────────────────────────── */
.sec { padding: 92px 0; }
.sec-tint { background: var(--bg-soft); }
.sec-head { text-align: center; max-width: 680px; margin: 0 auto 52px; }
.sec-tag {
  display: inline-block; padding: 5px 14px; border-radius: 999px;
  background: color-mix(in srgb, var(--brand) 10%, transparent);
  color: var(--brand); font-size: 12.5px; font-weight: 700;
  letter-spacing: .5px; margin-bottom: 14px;
}
.sec-head h2 {
  font-size: clamp(26px, 3.2vw, 38px); margin: 0 0 14px;
  letter-spacing: -.8px; font-weight: 800; line-height: 1.25;
}
.sec-head p { font-size: 16px; color: var(--ink-soft); margin: 0; }

/* ─── 特性卡片 ──────────────────────────────────────────── */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.card {
  background: var(--bg); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 28px 24px;
  transition: transform .25s, box-shadow .25s, border-color .25s;
}
.card:hover { transform: translateY(-5px); box-shadow: var(--shadow); border-color: color-mix(in srgb, var(--brand) 30%, var(--line)); }
.card-ico {
  width: 46px; height: 46px; border-radius: 12px; margin-bottom: 16px;
  display: grid; place-items: center; font-size: 21px;
  background: linear-gradient(135deg, color-mix(in srgb, var(--brand) 14%, transparent), color-mix(in srgb, var(--accent) 12%, transparent));
}
.card h3 { font-size: 17px; margin: 0 0 9px; font-weight: 700; }
.card p { font-size: 14.5px; color: var(--ink-soft); margin: 0; }
.card code {
  background: var(--bg-tint); padding: 1px 6px; border-radius: 5px;
  font-size: 12.5px; font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}

/* ─── 截图展示（Tab 切换）─────────────────────────────── */
.tabs { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin-bottom: 32px; }
.tab {
  padding: 9px 18px; border-radius: 10px; border: 1px solid var(--line);
  background: var(--bg); color: var(--ink-soft); font-size: 14px;
  font-weight: 500; font-family: inherit; cursor: pointer;
  transition: all .2s;
}
.tab:hover { border-color: var(--brand); color: var(--brand); }
.tab.active {
  background: linear-gradient(135deg, var(--brand), var(--brand-light));
  color: #fff; border-color: transparent; font-weight: 600;
  box-shadow: 0 6px 20px rgba(79, 70, 229, .3);
}

.panel { display: none; }
.panel.active { display: block; animation: fade .35s ease; }
@keyframes fade { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }

.panel-box {
  display: grid; grid-template-columns: 1fr 1.9fr; gap: 34px; align-items: center;
  background: var(--bg); border: 1px solid var(--line);
  border-radius: var(--radius-lg); padding: 34px; box-shadow: var(--shadow);
}
.panel-txt h3 { font-size: 21px; margin: 0 0 12px; font-weight: 700; }
.panel-txt p { font-size: 15px; color: var(--ink-soft); margin: 0 0 16px; }
.panel-txt ul { margin: 0; padding-left: 20px; font-size: 14px; color: var(--ink-soft); }
.panel-txt li { margin: 7px 0; }
.panel-txt strong { color: var(--ink); }
.panel-img { border-radius: 12px; overflow: hidden; border: 1px solid var(--line); box-shadow: var(--shadow); }

/* ─── 快速开始（步骤）─────────────────────────────────── */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.step {
  background: var(--bg); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 26px; position: relative;
}
.step-n {
  position: absolute; top: -14px; left: 24px;
  width: 30px; height: 30px; border-radius: 9px;
  background: linear-gradient(135deg, var(--brand), var(--brand-light));
  color: #fff; display: grid; place-items: center;
  font-size: 14px; font-weight: 700; box-shadow: 0 5px 16px rgba(79, 70, 229, .34);
}
.step h3 { font-size: 16.5px; margin: 12px 0 10px; font-weight: 700; }
.step p { font-size: 14px; color: var(--ink-soft); margin: 0 0 12px; }

/* 代码块 */
.code {
  background: #0d1424; border-radius: var(--radius-sm);
  padding: 16px 18px; overflow-x: auto; position: relative;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 12.5px; line-height: 1.85; color: #cbd5e1;
  border: 1px solid rgba(148, 163, 184, .16);
}
.code .c { color: #64748b; }          /* 注释 */
.code .k { color: #c4b5fd; }          /* 命令 */
.code .s { color: #86efac; }          /* 字符串/路径 */
.copy {
  position: absolute; top: 9px; right: 9px;
  padding: 4px 10px; border-radius: 6px;
  background: rgba(148, 163, 184, .14); border: 0;
  color: #cbd5e1; font-size: 11.5px; font-family: inherit; cursor: pointer;
  opacity: 0; transition: opacity .2s, background .2s;
}
.code:hover .copy { opacity: 1; }
.copy:hover { background: rgba(148, 163, 184, .28); }
.copy.done { background: rgba(34, 197, 94, .26); color: #86efac; }

/* ─── 部署文档 ──────────────────────────────────────────── */
.doc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.doc {
  background: var(--bg); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 26px;
}
.doc h3 { font-size: 17px; margin: 0 0 8px; display: flex; align-items: center; gap: 9px; }
.doc > p { font-size: 14px; color: var(--ink-soft); margin: 0 0 16px; }

.note {
  border-left: 3px solid var(--accent-warm);
  background: color-mix(in srgb, var(--accent-warm) 9%, transparent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 13px 16px; font-size: 13.5px; color: var(--ink-soft); margin: 16px 0 0;
}
.note b { color: var(--ink); }
.note code {
  background: color-mix(in srgb, var(--ink) 8%, transparent); padding: 1px 5px;
  border-radius: 4px; font-size: 12.5px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}

/* 表格 */
.tbl { width: 100%; border-collapse: collapse; font-size: 14px; }
.tbl th, .tbl td { text-align: left; padding: 11px 14px; border-bottom: 1px solid var(--line); }
.tbl th { background: var(--bg-tint); font-weight: 600; font-size: 13px; color: var(--ink-soft); }
.tbl tr:last-child td { border-bottom: 0; }
.tbl code {
  background: var(--bg-tint); padding: 1px 6px; border-radius: 5px; font-size: 12.5px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}
.tbl-wrap {
  border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; overflow-x: auto;
}

/* ─── FAQ ───────────────────────────────────────────────── */
.faq { max-width: 780px; margin: 0 auto; }
.qa {
  border: 1px solid var(--line); border-radius: var(--radius-sm);
  margin-bottom: 11px; overflow: hidden; background: var(--bg);
  transition: border-color .2s;
}
.qa[open] { border-color: color-mix(in srgb, var(--brand) 36%, var(--line)); }
.qa summary {
  padding: 15px 20px; cursor: pointer; font-weight: 600; font-size: 15px;
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  list-style: none;
}
.qa summary::-webkit-details-marker { display: none; }
.qa summary::after {
  content: "+"; font-size: 19px; color: var(--ink-mute);
  transition: transform .2s; flex-shrink: 0; line-height: 1;
}
.qa[open] summary::after { transform: rotate(45deg); color: var(--brand); }
.qa-body { padding: 0 20px 18px; font-size: 14.5px; color: var(--ink-soft); }
.qa-body p { margin: 0 0 10px; }
.qa-body p:last-child { margin-bottom: 0; }
.qa-body code {
  background: var(--bg-tint); padding: 1px 6px; border-radius: 5px; font-size: 12.5px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}

/* ─── 捐赠（模态框）──────────────────────────────────────── */
.modal {
  position: fixed; inset: 0; z-index: 2000;
  display: none;
  align-items: center; justify-content: center;
  padding: 24px;
}
.modal.open { display: flex; animation: modalFade .25s ease; }
@keyframes modalFade { from { opacity: 0; } to { opacity: 1; } }
.modal-mask {
  position: absolute; inset: 0;
  background: rgba(15, 23, 42, .55);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}
.modal-dialog {
  position: relative;
  width: 100%;
  max-width: 480px;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 36px 30px 30px;
  text-align: center;
  box-shadow: 0 30px 80px rgba(15, 23, 42, .35);
  animation: modalIn .3s cubic-bezier(.2, .9, .3, 1.3);
}
@keyframes modalIn {
  from { opacity: 0; transform: translateY(14px) scale(.96); }
  to   { opacity: 1; transform: none; }
}
.modal-close {
  position: absolute; top: 12px; right: 12px;
  width: 32px; height: 32px; border-radius: 8px;
  border: 0; background: transparent;
  font-size: 22px; line-height: 1; color: var(--ink-mute);
  cursor: pointer; transition: all .2s;
}
.modal-close:hover { background: var(--bg-tint); color: var(--ink); }
.modal-head { margin-bottom: 18px; }
.modal-head .sec-tag { margin-bottom: 10px; }
.modal-head h3 {
  font-size: 22px; margin: 0 0 8px; font-weight: 700; letter-spacing: -.4px;
}
.modal-head p { font-size: 14px; color: var(--ink-soft); margin: 0; }

.pay-tabs { display: flex; justify-content: center; gap: 10px; margin: 20px 0 18px; }
.pay-tab {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 10px 22px; border-radius: 11px;
  border: 1.5px solid var(--line); background: var(--bg);
  font-size: 14.5px; font-family: inherit; color: var(--ink-soft);
  cursor: pointer; font-weight: 500; transition: all .2s;
}
.pay-tab:hover { border-color: var(--brand); }
.pay-tab.active {
  border-color: var(--brand); background: color-mix(in srgb, var(--brand) 8%, transparent);
  color: var(--brand); font-weight: 700;
}
.qr-shell { display: inline-block; padding: 14px; border-radius: var(--radius); background: #fff; box-shadow: var(--shadow); }
.qr-shell img { width: 216px; height: 216px; object-fit: contain; }
.qr-tip { font-size: 14px; color: var(--ink-mute); margin-top: 14px; }

/* ─── CTA ───────────────────────────────────────────────── */
.cta {
  text-align: center; padding: 76px 34px; border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--brand-dark), var(--brand) 45%, #7c3aed 100%);
  color: #fff; position: relative; overflow: hidden;
}
.cta::after {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(60% 60% at 82% 12%, rgba(236, 72, 153, .34), transparent 68%);
}
.cta > * { position: relative; z-index: 1; }
.cta h2 { font-size: clamp(24px, 3vw, 34px); margin: 0 0 12px; font-weight: 800; letter-spacing: -.6px; }
.cta p { font-size: 16px; opacity: .9; margin: 0 0 28px; }
.cta .btn-ghost {
  background: rgba(255, 255, 255, .14); color: #fff;
  border-color: rgba(255, 255, 255, .3);
  backdrop-filter: blur(8px);
}
.cta .btn-ghost:hover { background: rgba(255, 255, 255, .24); color: #fff; border-color: rgba(255, 255, 255, .5); }
.cta .btn-primary { background: #fff; color: var(--brand-dark); box-shadow: 0 12px 40px rgba(0, 0, 0, .22); }
.cta .btn-primary:hover { color: var(--brand-dark); background: #fff; }

/* ─── 页脚 ──────────────────────────────────────────────── */
.foot { background: var(--bg-soft); border-top: 1px solid var(--line); padding: 52px 0 26px; }
.foot-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 34px; margin-bottom: 34px; }
.foot h4 { font-size: 14px; margin: 0 0 14px; font-weight: 700; }
.foot ul { list-style: none; padding: 0; margin: 0; }
.foot li { margin: 9px 0; }
.foot a { font-size: 14px; color: var(--ink-soft); }
.foot a:hover { color: var(--brand); }
.foot-desc { font-size: 14px; color: var(--ink-soft); margin: 14px 0 0; max-width: 300px; }
.foot-bot {
  border-top: 1px solid var(--line); padding-top: 22px;
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px;
  font-size: 13.5px; color: var(--ink-mute);
}

/* ─── 回到顶部 ──────────────────────────────────────────── */
.top-btn {
  position: fixed; right: 26px; bottom: 26px; z-index: 900;
  width: 44px; height: 44px; border-radius: 12px;
  border: 1px solid var(--line); background: var(--bg);
  color: var(--ink-soft); cursor: pointer; font-size: 17px;
  display: grid; place-items: center; box-shadow: var(--shadow);
  opacity: 0; visibility: hidden; transform: translateY(10px);
  transition: all .25s;
}
.top-btn.show { opacity: 1; visibility: visible; transform: none; }
.top-btn:hover { color: var(--brand); border-color: var(--brand); }

/* ─── 进入动画 ──────────────────────────────────────────── */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* ─── 响应式 ────────────────────────────────────────────── */
@media (max-width: 1024px) {
  .hero-grid { grid-template-columns: 1fr; gap: 44px; }
  .shot-main { transform: none; max-height: none; }
  .shot-main img { object-fit: contain; height: auto; }
  .cards, .steps { grid-template-columns: repeat(2, 1fr); }
  .panel-box { grid-template-columns: 1fr; }
  .foot-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  /* 移动端导航：折叠成抽屉 */
  .nav-toggle { display: grid; }
  .nav-links {
    position: fixed; top: var(--nav-h); left: 0; right: 0;
    flex-direction: column; gap: 2px; padding: 14px 20px 20px;
    background: var(--bg); border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow); margin: 0;
    transform: translateY(-130%); transition: transform .3s ease;
    max-height: calc(100vh - var(--nav-h)); overflow-y: auto;
  }
  .nav-links.open { transform: none; }
  .nav-links a { padding: 12px 14px; font-size: 15px; }

  .stats { grid-template-columns: repeat(2, 1fr); }
  .cards, .steps, .doc-grid { grid-template-columns: 1fr; }
  .sec { padding: 62px 0; }
  .hero { padding: calc(var(--nav-h) + 46px) 0 62px; }
  .shot-float { display: none; }   /* 移动端窄，叠图会遮挡主图 */
  .pay-tabs { flex-wrap: wrap; }
  .foot-grid { grid-template-columns: 1fr; gap: 26px; }
  .cta { padding: 52px 22px; }
  .modal-dialog { padding: 28px 20px 22px; }
  .pay-tabs { flex-wrap: wrap; }
  .qr-shell img { width: 180px; height: 180px; }
}