/* ===========================================================
   微商截图大师 - 官方下载站样式
   设计风格：深色科技感 Hero + 浅色内容区 + 渐变主色
   断点：>=1200 桌面 / 1024 笔记本 / 768 平板 / 480 手机
   =========================================================== */

:root {
  --brand: #5b5bd6;
  --brand-2: #7c3aed;
  --brand-3: #ff6a3d;
  --pink: #ff4d87;
  --ink: #14162b;
  --ink-2: #3d4166;
  --muted: #6b7089;
  --line: #e8eaf5;
  --bg: #ffffff;
  --bg-soft: #f6f7fc;
  --radius: 18px;
  --radius-lg: 26px;
  --shadow-sm: 0 4px 16px rgba(20, 22, 43, .06);
  --shadow: 0 18px 40px rgba(20, 22, 43, .10);
  --shadow-lg: 0 30px 70px rgba(20, 22, 43, .16);
  --grad: linear-gradient(135deg, #6a6ae8 0%, #7c3aed 50%, #ff5f6d 100%);
  --grad-soft: linear-gradient(135deg, rgba(106, 106, 232, .12), rgba(255, 95, 109, .10));
  --header-h: 72px;
  --ease: cubic-bezier(.22, .61, .36, 1);
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 12px);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink-2);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { margin: 0; padding: 0; list-style: none; }
h1, h2, h3, h4 { color: var(--ink); line-height: 1.3; margin: 0 0 .6em; font-weight: 800; letter-spacing: -.01em; }
p { margin: 0 0 1em; }
strong { color: var(--ink); font-weight: 700; }

.container { width: min(1200px, 100% - 48px); margin-inline: auto; }

.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 999;
  background: var(--brand); color: #fff; padding: 10px 18px; border-radius: 0 0 10px 0;
}
.skip-link:focus { left: 0; }

:focus-visible { outline: 3px solid var(--brand); outline-offset: 3px; border-radius: 6px; }

.gradient-text {
  display: block;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

/* ---------------- 按钮 ---------------- */
.btn {
  --btn-bg: var(--grad);
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 13px 26px; border: 0; border-radius: 999px;
  font-size: 15px; font-weight: 700; letter-spacing: .02em;
  cursor: pointer; transition: transform .25s var(--ease), box-shadow .25s var(--ease), background .25s var(--ease);
  white-space: nowrap;
}
.btn svg { width: 20px; height: 20px; }
.btn-primary { background: var(--grad); color: #fff; box-shadow: 0 12px 26px rgba(124, 58, 237, .34); }
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 18px 34px rgba(124, 58, 237, .44); }
.btn-ghost { background: rgba(255, 255, 255, .08); color: #fff; border: 1.5px solid rgba(255, 255, 255, .34); backdrop-filter: blur(6px); }
.btn-ghost:hover { background: rgba(255, 255, 255, .18); transform: translateY(-3px); }
.btn-light { background: #fff; color: var(--brand); box-shadow: 0 14px 30px rgba(0, 0, 0, .18); }
.btn-light:hover { transform: translateY(-3px); }
.btn-lg { padding: 16px 34px; font-size: 16.5px; }
.btn-sm { padding: 10px 20px; font-size: 14px; }
.btn-block { width: 100%; }

/* ---------------- 头部导航 ---------------- */
.site-header {
  position: fixed; inset: 0 0 auto 0; z-index: 100;
  height: var(--header-h);
  background: rgba(255, 255, 255, .06);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(255, 255, 255, .1);
  transition: background .3s var(--ease), box-shadow .3s var(--ease), border-color .3s var(--ease);
}
.header-inner { height: 100%; display: flex; align-items: center; justify-content: space-between; gap: 24px; }

.logo { display: flex; align-items: center; gap: 12px; }
.logo-mark {
  width: 42px; height: 42px; flex: none; border-radius: 13px;
  background: var(--grad); color: #fff;
  display: grid; place-items: center;
  font-size: 19px; font-weight: 800;
  box-shadow: 0 8px 20px rgba(124, 58, 237, .4);
}
.logo-text { display: flex; flex-direction: column; line-height: 1.2; }
.logo-text strong { font-size: 18px; color: #fff; letter-spacing: .01em; }
.logo-text em { font-size: 11px; font-style: normal; color: rgba(255, 255, 255, .62); letter-spacing: .08em; text-transform: uppercase; }

.nav { display: flex; align-items: center; gap: 30px; }
.nav ul { display: flex; align-items: center; gap: 4px; }
.nav-link {
  position: relative; display: block; padding: 8px 14px; border-radius: 10px;
  font-size: 15px; font-weight: 600; color: rgba(255, 255, 255, .88);
  transition: color .25s var(--ease), background .25s var(--ease);
}
.nav-link::after {
  content: ""; position: absolute; left: 14px; right: 14px; bottom: 2px; height: 2px;
  background: var(--grad); border-radius: 2px; transform: scaleX(0); transform-origin: center;
  transition: transform .3s var(--ease);
}
.nav-link:hover { color: #fff; background: rgba(255, 255, 255, .1); }
.nav-link:hover::after, .nav-link.active::after { transform: scaleX(1); }
.nav-link.active { color: #fff; }

/* 滚动后（进入浅色区）变白底 */
.site-header.scrolled {
  background: rgba(255, 255, 255, .92);
  border-bottom-color: var(--line);
  box-shadow: 0 6px 24px rgba(20, 22, 43, .07);
}
.site-header.scrolled .logo-text strong { color: var(--ink); }
.site-header.scrolled .logo-text em { color: var(--muted); }
.site-header.scrolled .nav-link { color: var(--ink-2); }
.site-header.scrolled .nav-link:hover { color: var(--brand); background: var(--bg-soft); }
.site-header.scrolled .nav-link.active { color: var(--brand); }

.nav-toggle {
  display: none; width: 44px; height: 44px; border: 0; border-radius: 12px;
  background: rgba(255, 255, 255, .14); cursor: pointer;
  padding: 0; place-items: center; gap: 5px;
}
.nav-toggle span { display: block; width: 20px; height: 2px; background: #fff; border-radius: 2px; transition: transform .3s var(--ease), opacity .2s; }
.site-header.scrolled .nav-toggle { background: var(--bg-soft); }
.site-header.scrolled .nav-toggle span { background: var(--ink); }
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------------- Hero ---------------- */
.hero {
  position: relative; overflow: hidden;
  padding: calc(var(--header-h) + 78px) 0 90px;
  background: radial-gradient(120% 120% at 15% 10%, #23265c 0%, #171936 45%, #0f1029 100%);
  color: #fff;
}
.hero-bg { position: absolute; inset: 0; pointer-events: none; }
.blob { position: absolute; border-radius: 50%; filter: blur(70px); opacity: .55; }
.blob-1 { width: 520px; height: 520px; top: -140px; left: -120px; background: #6a6ae8; animation: float 14s ease-in-out infinite; }
.blob-2 { width: 460px; height: 460px; bottom: -160px; right: -80px; background: #ff5f6d; opacity: .38; animation: float 18s ease-in-out infinite reverse; }
.blob-3 { width: 380px; height: 380px; top: 30%; left: 45%; background: #7c3aed; opacity: .32; animation: float 20s ease-in-out infinite; }
.grid-lines {
  position: absolute; inset: 0;
  background-image: linear-gradient(rgba(255, 255, 255, .045) 1px, transparent 1px), linear-gradient(90deg, rgba(255, 255, 255, .045) 1px, transparent 1px);
  background-size: 62px 62px;
  mask-image: radial-gradient(90% 70% at 50% 30%, #000 20%, transparent 75%);
  -webkit-mask-image: radial-gradient(90% 70% at 50% 30%, #000 20%, transparent 75%);
}
@keyframes float {
  0%, 100% { transform: translate3d(0, 0, 0) scale(1); }
  50% { transform: translate3d(30px, -28px, 0) scale(1.08); }
}

.hero-inner {
  position: relative; display: grid; grid-template-columns: 1.05fr .95fr;
  gap: 60px; align-items: center;
}
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 7px 16px; margin-bottom: 22px; border-radius: 999px;
  background: rgba(255, 255, 255, .1); border: 1px solid rgba(255, 255, 255, .18);
  font-size: 13.5px; color: rgba(255, 255, 255, .9);
}
.dot { width: 8px; height: 8px; border-radius: 50%; background: #38e07b; box-shadow: 0 0 0 4px rgba(56, 224, 123, .22); }

.hero h1 {
  font-size: clamp(30px, 4.6vw, 56px);
  letter-spacing: -.02em; color: #fff; margin-bottom: 20px;
}
.hero h1 .gradient-text { font-size: clamp(26px, 3.9vw, 46px); margin-top: .12em; }
.hero-desc { font-size: clamp(15px, 1.35vw, 17.5px); color: rgba(255, 255, 255, .8); max-width: 620px; }
.hero-desc strong { color: #fff; }

.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin: 30px 0 26px; }
.hero-meta { display: flex; flex-wrap: wrap; gap: 10px 26px; font-size: 14px; color: rgba(255, 255, 255, .68); }
.hero-meta li { position: relative; padding-left: 20px; }
.hero-meta li::before {
  content: "✓"; position: absolute; left: 0; color: #38e07b; font-weight: 700;
}

/* 手机预览 */
.hero-visual { position: relative; display: grid; place-items: center; }
.phone-frame {
  position: relative; width: min(320px, 78vw); aspect-ratio: 9 / 18.5;
  border-radius: 42px; padding: 12px;
  background: linear-gradient(160deg, #2c2f5e, #14162b);
  box-shadow: 0 40px 80px rgba(0, 0, 0, .55), inset 0 0 0 1.5px rgba(255, 255, 255, .12);
  animation: rise 1s var(--ease) both;
}
@keyframes rise { from { opacity: 0; transform: translateY(40px); } to { opacity: 1; transform: none; } }
.phone-notch {
  position: absolute; top: 20px; left: 50%; transform: translateX(-50%);
  width: 92px; height: 22px; border-radius: 999px; background: #0c0d1e; z-index: 2;
}
.phone-screen {
  height: 100%; border-radius: 32px; overflow: hidden;
  background: #ededed; padding: 42px 14px 16px;
}
.chat { display: flex; flex-direction: column; gap: 12px; }
.chat-msg { display: flex; align-items: flex-start; gap: 8px; }
.chat-msg.right { flex-direction: row-reverse; }
.avatar {
  width: 32px; height: 32px; flex: none; border-radius: 8px;
  display: grid; place-items: center; color: #fff; font-size: 13px; font-weight: 700;
}
.chat-msg.left .avatar { background: linear-gradient(135deg, #8b8fe0, #5b5bd6); }
.chat-msg.right .avatar { background: linear-gradient(135deg, #ff8a5c, #ff4d87); }
.bubble {
  margin: 0; max-width: 74%; padding: 9px 12px; border-radius: 12px;
  font-size: 12.5px; line-height: 1.5; color: #1a1a1a; background: #fff;
  box-shadow: 0 2px 6px rgba(0, 0, 0, .07); position: relative;
}
.chat-msg.left .bubble { border-top-left-radius: 3px; }
.chat-msg.right .bubble { background: #95ec69; border-top-right-radius: 3px; }
.chat-card {
  margin: 4px 0; padding: 14px; border-radius: 12px; color: #fff;
  background: linear-gradient(135deg, #fa9e3b, #f57c2e);
  box-shadow: 0 8px 18px rgba(245, 124, 46, .35);
}
.card-title { font-size: 12px; opacity: .92; }
.card-amount { font-size: 26px; font-weight: 800; letter-spacing: .01em; }
.card-note { font-size: 11.5px; opacity: .85; }

.float-badge {
  position: absolute; padding: 10px 16px; border-radius: 14px;
  background: rgba(255, 255, 255, .1); border: 1px solid rgba(255, 255, 255, .2);
  backdrop-filter: blur(10px); box-shadow: 0 12px 30px rgba(0, 0, 0, .3);
  animation: bob 5s ease-in-out infinite;
}
.float-badge strong { display: block; font-size: 18px; color: #fff; }
.float-badge span { font-size: 12px; color: rgba(255, 255, 255, .7); }
.badge-a { top: 14%; left: -14px; }
.badge-b { bottom: 16%; right: -18px; animation-delay: -2s; }
@keyframes bob { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-12px); } }

/* 数据统计 */
.stats {
  position: relative; margin-top: 66px;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px;
  padding: 26px 18px; border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, .07); border: 1px solid rgba(255, 255, 255, .14);
  backdrop-filter: blur(12px);
}
.stats li { text-align: center; }
.stats strong {
  display: block; font-size: clamp(26px, 3vw, 38px); font-weight: 800;
  background: var(--grad); -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}
.stats span { font-size: 13.5px; color: rgba(255, 255, 255, .68); }

/* ---------------- 通用区块 ---------------- */
.section { padding: clamp(64px, 8vw, 108px) 0; }
.section-alt { background: var(--bg-soft); }

.section-head { max-width: 760px; margin: 0 auto clamp(38px, 5vw, 60px); text-align: center; }
.section-tag {
  display: inline-block; margin-bottom: 14px; padding: 5px 15px; border-radius: 999px;
  background: var(--grad-soft); color: var(--brand); font-size: 13px; font-weight: 700; letter-spacing: .1em;
}
.section-head h2 { font-size: clamp(25px, 3.1vw, 38px); }
.section-sub { color: var(--muted); font-size: clamp(15px, 1.2vw, 16.5px); }

/* ---------------- 软件介绍 ---------------- */
.intro-grid { display: grid; gap: clamp(36px, 4.5vw, 58px); }

.intro-gallery { display: grid; grid-template-columns: repeat(3, 1fr); gap: clamp(14px, 2vw, 24px); }
.gallery-item {
  position: relative; margin: 0; overflow: hidden;
  border-radius: var(--radius-lg); background: #fff;
  border: 1px solid var(--line); box-shadow: var(--shadow);
  display: flex; flex-direction: column; aspect-ratio: 16 / 25;
  transition: transform .4s var(--ease), box-shadow .4s var(--ease);
}
.gallery-item img {
  flex: 1 1 auto; min-height: 0; width: 100%;
  object-fit: cover; object-position: top center;
  transition: transform .6s var(--ease);
}
.gallery-item::after {
  content: ""; position: absolute; inset: 0 0 auto 0; height: 120px;
  background: linear-gradient(180deg, rgba(20, 22, 43, .18), transparent);
  opacity: 0; transition: opacity .4s var(--ease); pointer-events: none;
}
.gallery-item:hover { transform: translateY(-8px); box-shadow: var(--shadow-lg); }
.gallery-item:hover img { transform: scale(1.06); }
.gallery-item:hover::after { opacity: 1; }
.gallery-item figcaption {
  flex: none; padding: 13px 14px; font-size: 14px; font-weight: 700; color: var(--ink);
  text-align: center; border-top: 1px solid var(--line); background: #fff;
}

.intro-text { max-width: 940px; margin-inline: auto; }
.intro-text h3 { font-size: clamp(20px, 2.2vw, 27px); }
.intro-text p { color: var(--muted); }
.check-list { margin: 24px 0 30px; display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px 24px; }
.check-list li { position: relative; padding-left: 32px; color: var(--ink-2); font-size: 15.5px; }
.check-list li::before {
  content: "✓"; position: absolute; left: 0; top: 1px;
  width: 22px; height: 22px; border-radius: 50%;
  background: var(--grad-soft); color: var(--brand);
  font-size: 13px; font-weight: 800; display: grid; place-items: center;
}

/* ---------------- 软件特点 ---------------- */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.feature-card {
  position: relative; overflow: hidden;
  padding: 32px 28px; border-radius: var(--radius-lg);
  background: #fff; border: 1px solid var(--line);
  transition: transform .35s var(--ease), box-shadow .35s var(--ease), border-color .35s var(--ease);
}
.feature-card::before {
  content: ""; position: absolute; inset: 0; opacity: 0; transition: opacity .35s var(--ease);
  background: var(--grad-soft);
}
.feature-card:hover { transform: translateY(-8px); box-shadow: var(--shadow-lg); border-color: transparent; }
.feature-card:hover::before { opacity: 1; }
.feature-card > * { position: relative; }
.feature-icon {
  display: grid; place-items: center; width: 56px; height: 56px; margin-bottom: 18px;
  border-radius: 16px; font-size: 26px; background: var(--grad-soft);
}
.feature-card h3 { font-size: 19px; }
.feature-card p { color: var(--muted); font-size: 15px; margin: 0; }

/* ---------------- 使用方法 ---------------- */
.steps { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; counter-reset: step; }
.step {
  display: flex; gap: 20px; padding: 26px; border-radius: var(--radius-lg);
  background: #fff; border: 1px solid var(--line); box-shadow: var(--shadow-sm);
  transition: transform .3s var(--ease), box-shadow .3s var(--ease);
}
.step:hover { transform: translateY(-5px); box-shadow: var(--shadow); }
.step-num {
  flex: none; width: 54px; height: 54px; border-radius: 16px;
  display: grid; place-items: center;
  font-size: 19px; font-weight: 800; color: #fff; background: var(--grad);
  box-shadow: 0 10px 22px rgba(124, 58, 237, .3);
}
.step-body h3 { font-size: 18px; margin-bottom: 6px; }
.step-body p { color: var(--muted); font-size: 15px; margin: 0; }

.tips {
  margin-top: 26px; padding: 26px 30px; border-radius: var(--radius-lg);
  background: linear-gradient(135deg, rgba(106, 106, 232, .1), rgba(255, 95, 109, .08));
  border: 1px dashed rgba(91, 91, 214, .3);
}
.tips h3 { font-size: 17px; margin-bottom: 10px; }
.tips ul { display: grid; gap: 8px; }
.tips li { position: relative; padding-left: 22px; font-size: 15px; color: var(--ink-2); }
.tips li::before { content: "•"; position: absolute; left: 6px; color: var(--brand); font-weight: 800; }

/* ---------------- 用户评价 ---------------- */
.review-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.review-card {
  display: flex; flex-direction: column; gap: 14px;
  padding: 28px 26px; border-radius: var(--radius-lg);
  background: #fff; border: 1px solid var(--line);
  transition: transform .35s var(--ease), box-shadow .35s var(--ease);
}
.review-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.review-stars { color: #ffb400; font-size: 17px; letter-spacing: 2px; }
.review-card p { color: var(--ink-2); font-size: 15px; margin: 0; flex: 1; }
.review-card footer { display: flex; align-items: center; gap: 12px; padding-top: 14px; border-top: 1px solid var(--line); }
.review-avatar {
  width: 42px; height: 42px; flex: none; border-radius: 50%;
  display: grid; place-items: center; color: #fff; font-weight: 700;
  background: var(--grad);
}
.review-card footer strong { display: block; font-size: 15px; }
.review-card footer em { font-style: normal; font-size: 13px; color: var(--muted); }

/* ---------------- 下载帮助 ---------------- */
.help-layout { display: grid; grid-template-columns: 1.5fr 1fr; gap: 28px; align-items: start; }
.faq { display: grid; gap: 12px; }
.faq-item {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; transition: box-shadow .3s var(--ease), border-color .3s var(--ease);
}
.faq-item[open] { border-color: rgba(91, 91, 214, .35); box-shadow: var(--shadow); }
.faq-item summary {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 18px 22px; cursor: pointer; list-style: none;
  font-size: 16px; font-weight: 700; color: var(--ink);
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+"; flex: none; width: 26px; height: 26px; border-radius: 50%;
  display: grid; place-items: center; font-size: 18px; font-weight: 700;
  color: var(--brand); background: var(--grad-soft);
  transition: transform .3s var(--ease);
}
.faq-item[open] summary::after { content: "−"; transform: rotate(180deg); }
.faq-body { padding: 0 22px 20px; }
.faq-body p { margin: 0; color: var(--muted); font-size: 15px; }

.download-card {
  position: sticky; top: calc(var(--header-h) + 20px);
  padding: 32px 28px; border-radius: var(--radius-lg); color: #fff;
  background: linear-gradient(150deg, #2b2e63 0%, #1b1d3c 60%, #3a2160 100%);
  box-shadow: var(--shadow-lg); overflow: hidden;
}
.download-card::after {
  content: ""; position: absolute; width: 260px; height: 260px; right: -90px; top: -90px;
  border-radius: 50%; background: rgba(124, 58, 237, .45); filter: blur(60px);
}
.download-card > * { position: relative; }
.download-card h3 { color: #fff; font-size: 21px; }
.download-card p { color: rgba(255, 255, 255, .75); font-size: 14.5px; }
.download-card ul { display: grid; gap: 9px; margin: 18px 0 22px; }
.download-card li { font-size: 14.5px; color: rgba(255, 255, 255, .82); padding-left: 20px; position: relative; }
.download-card li::before { content: "▸"; position: absolute; left: 0; color: #ffb400; }
.download-note { margin: 14px 0 0; font-size: 13px; color: rgba(255, 255, 255, .55); text-align: center; }

/* ---------------- 底部 CTA ---------------- */
.cta {
  padding: clamp(56px, 7vw, 92px) 0;
  background: var(--grad); color: #fff; text-align: center;
}
.cta-inner { max-width: 720px; }
.cta h2 { color: #fff; font-size: clamp(24px, 3vw, 36px); }
.cta p { color: rgba(255, 255, 255, .85); margin-bottom: 28px; }

/* ---------------- 页脚 ---------------- */
.site-footer { background: #0f1029; color: rgba(255, 255, 255, .6); padding: 62px 0 26px; font-size: 14.5px; }
.footer-inner { display: grid; grid-template-columns: 1.6fr 1fr 1fr; gap: 40px; padding-bottom: 34px; }
.site-footer h3 { color: #fff; font-size: 16px; margin-bottom: 14px; }
.footer-brand p { margin-top: 14px; max-width: 340px; }
.footer-nav ul, .footer-contact ul { display: grid; gap: 9px; }
.site-footer a:hover { color: #fff; }
.footer-bottom {
  display: flex; flex-wrap: wrap; gap: 10px 24px; justify-content: space-between;
  padding-top: 22px; border-top: 1px solid rgba(255, 255, 255, .1); font-size: 13.5px;
}
.footer-bottom p { margin: 0; }

/* ---------------- 回到顶部 ---------------- */
.to-top {
  position: fixed; right: 24px; bottom: 24px; z-index: 90;
  width: 48px; height: 48px; border: 0; border-radius: 50%;
  background: var(--grad); color: #fff; cursor: pointer;
  display: grid; place-items: center;
  box-shadow: 0 14px 30px rgba(124, 58, 237, .4);
  opacity: 0; visibility: hidden; transform: translateY(14px);
  transition: opacity .3s var(--ease), transform .3s var(--ease), visibility .3s;
}
.to-top svg { width: 22px; height: 22px; }
.to-top.show { opacity: 1; visibility: visible; transform: none; }

/* ---------------- 滚动出现动画 ---------------- */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.in { opacity: 1; transform: none; }

/* ===========================================================
   响应式：笔记本 / 平板 / 手机
   =========================================================== */
@media (max-width: 1080px) {
  .nav ul { gap: 0; }
  .nav-link { padding: 8px 10px; font-size: 14.5px; }
  .nav { gap: 16px; }
  .hero-inner { gap: 40px; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .review-grid { grid-template-columns: repeat(2, 1fr); }
  .help-layout { grid-template-columns: 1fr; }
  .download-card { position: static; }
}

@media (max-width: 900px) {
  :root { --header-h: 64px; }
  .nav-toggle { display: grid; }
  .nav {
    position: fixed; inset: var(--header-h) 0 auto 0;
    flex-direction: column; align-items: stretch; gap: 6px;
    padding: 14px 20px 22px;
    background: rgba(255, 255, 255, .97);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 20px 40px rgba(20, 22, 43, .12);
    transform: translateY(-12px); opacity: 0; visibility: hidden;
    transition: transform .3s var(--ease), opacity .3s var(--ease), visibility .3s;
  }
  .nav.open { transform: none; opacity: 1; visibility: visible; }
  .nav ul { flex-direction: column; align-items: stretch; gap: 2px; }
  .nav-link { padding: 13px 14px; font-size: 16px; color: var(--ink-2); border-radius: 12px; }
  .nav-link::after { display: none; }
  .nav-link:hover, .nav-link.active { color: var(--brand); background: var(--bg-soft); }
  .nav-download { margin-top: 10px; width: 100%; padding: 14px; font-size: 16px; }

  .hero { padding-top: calc(var(--header-h) + 52px); }
  .hero-inner { grid-template-columns: 1fr; gap: 48px; text-align: center; }
  .hero-copy { order: 1; }
  .hero-visual { order: 2; }
  .hero-desc { margin-inline: auto; }
  .hero-actions, .hero-meta { justify-content: center; }
  .eyebrow { justify-content: center; }
  .badge-a { left: 0; }
  .badge-b { right: 0; }
  .stats { grid-template-columns: repeat(2, 1fr); gap: 22px 12px; margin-top: 48px; }
  .steps { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr 1fr; gap: 30px; }
  .footer-brand { grid-column: span 2; }
}

@media (max-width: 640px) {
  .container { width: calc(100% - 32px); }
  body { font-size: 15.5px; }
  .section { padding: 56px 0; }
  .hero { padding-bottom: 64px; }
  .phone-frame { width: min(270px, 72vw); }
  .float-badge { padding: 8px 12px; }
  .float-badge strong { font-size: 15px; }
  .float-badge span { font-size: 11px; }
  .badge-a { top: 6%; left: -6px; }
  .badge-b { bottom: 8%; right: -6px; }
  .hero-actions .btn { width: 100%; }
  .btn-lg { padding: 15px 24px; }
  .feature-grid { grid-template-columns: 1fr; }
  .review-grid { grid-template-columns: 1fr; }
  .intro-gallery {
    display: flex; gap: 12px; overflow-x: auto;
    scroll-snap-type: x mandatory; -webkit-overflow-scrolling: touch;
    padding-bottom: 12px; scrollbar-width: thin;
  }
  .gallery-item { flex: 0 0 74%; scroll-snap-align: start; }
  .check-list { grid-template-columns: 1fr; gap: 10px; }
  .intro-text .btn { width: 100%; }
  .step { flex-direction: column; gap: 14px; }
  .tips { padding: 22px 20px; }
  .footer-inner { grid-template-columns: 1fr; }
  .footer-brand { grid-column: span 1; }
  .footer-bottom { justify-content: center; text-align: center; }
  .to-top { right: 14px; bottom: 14px; width: 44px; height: 44px; }
}

@media (max-width: 400px) {
  .stats { grid-template-columns: 1fr; }
  .logo-text em { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; }
}