/* ============================================================
   popiku 破皮裤 · 介绍页样式
   主色取自 logo 蓝：#3497e6
   ============================================================ */

:root {
  --blue-50:  #eef7fe;
  --blue-100: #d9eefd;
  --blue-200: #b3dcfb;
  --blue-300: #7fc0f3;
  --blue-500: #3497e6;
  --blue-600: #1f7fcc;
  --blue-700: #1666ab;
  --navy-900: #0c2440;
  --navy-800: #10355c;
  --navy-700: #144575;

  --ink:   #1d2b45;
  --gray:  #5c6b80;
  --light: #8a98ab;
  --line:  #e3edf7;
  --bg:    #f4f9fe;
  --white: #ffffff;

  --radius: 18px;
  --radius-lg: 26px;
  --shadow-sm: 0 4px 14px rgba(16, 53, 92, .08);
  --shadow:    0 14px 40px rgba(16, 53, 92, .12);
  --shadow-lg: 0 26px 70px rgba(12, 36, 64, .26);
  --ease: cubic-bezier(.22, .68, .28, 1);
}

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

html { scroll-behavior: smooth; }

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

img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }

.container {
  width: min(1180px, 92%);
  margin: 0 auto;
}
.container-narrow { width: min(860px, 92%); }

section { scroll-margin-top: 76px; }

/* ---------- 通用按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .5px;
  transition: transform .25s var(--ease), box-shadow .25s var(--ease),
              background .25s, border-color .25s, color .25s;
  white-space: nowrap;
}
.btn-lg { padding: 15px 34px; font-size: 16px; }
.btn-ico {
  display: inline-grid;
  place-items: center;
  width: 22px; height: 22px;
  border-radius: 50%;
  background: rgba(255, 255, 255, .25);
  font-size: 13px;
  line-height: 1;
}
.btn-primary {
  color: #fff;
  background: linear-gradient(135deg, var(--blue-300), var(--blue-500) 45%, var(--blue-600));
  box-shadow: 0 12px 30px rgba(31, 127, 204, .45);
}
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 18px 40px rgba(31, 127, 204, .55); }
.btn-ghost {
  color: #fff;
  border: 1.5px solid rgba(255, 255, 255, .45);
  background: rgba(255, 255, 255, .06);
  backdrop-filter: blur(6px);
}
.btn-ghost:hover { border-color: #fff; background: rgba(255, 255, 255, .16); transform: translateY(-3px); }

/* ---------- logo 占位（img 留空时显示蓝色立方体占位） ---------- */
.logo-mark {
  position: relative;
  display: inline-grid;
  place-items: center;
  border-radius: 26%;
  overflow: hidden;
  flex: none;
  background: linear-gradient(145deg, #52abec 0%, var(--blue-500) 45%, var(--blue-700) 100%);
  box-shadow: 0 8px 20px rgba(31, 127, 204, .35), inset 0 1px 0 rgba(255,255,255,.35);
}
.logo-mark::before {
  content: "";
  width: 62%; height: 62%;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 64 64' fill='none'%3E%3Cpath d='M32 6 56 19v26L32 58 8 45V19L32 6Z' stroke='white' stroke-width='3.4' stroke-linejoin='round' opacity='.95'/%3E%3Cpath d='M8 19l24 13 24-13M32 32v26' stroke='white' stroke-width='3.4' stroke-linejoin='round' opacity='.95'/%3E%3C/svg%3E") center/contain no-repeat;
  opacity: .9;
}
.logo-mark img {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  object-fit: cover;
  border-radius: inherit;
}
.logo-mark img.is-empty { opacity: 0; }
.logo-mark-sm { width: 42px; height: 42px; }
.logo-mark-lg { width: 84px; height: 84px; border-radius: 24%; }

/* ============================================================
   顶部导航
   ============================================================ */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 18px 0;
  transition: padding .3s var(--ease), background .3s, box-shadow .3s;
}
.site-header.scrolled {
  padding: 10px 0;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: blur(14px);
  box-shadow: 0 6px 24px rgba(12, 36, 64, .1);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand { display: inline-flex; align-items: center; gap: 12px; }
.brand-name {
  font-size: 21px;
  font-weight: 800;
  color: #fff;
  letter-spacing: .5px;
  transition: color .3s;
}
.brand-name em {
  font-style: normal;
  font-size: 12px;
  font-weight: 500;
  margin-left: 7px;
  padding: 2px 8px;
  border-radius: 999px;
  color: #fff;
  background: rgba(255, 255, 255, .18);
  vertical-align: middle;
}
.site-header.scrolled .brand-name { color: var(--ink); }
.site-header.scrolled .brand-name em { background: var(--blue-50); color: var(--blue-600); }

.main-nav { display: flex; align-items: center; gap: 34px; }
.main-nav > a {
  font-size: 15px;
  font-weight: 500;
  color: rgba(255, 255, 255, .88);
  position: relative;
  transition: color .25s;
}
.main-nav > a::after {
  content: "";
  position: absolute;
  left: 0; bottom: -6px;
  width: 0; height: 2px;
  border-radius: 2px;
  background: var(--blue-300);
  transition: width .3s var(--ease);
}
.main-nav > a:hover { color: #fff; }
.main-nav > a:hover::after { width: 100%; }
.site-header.scrolled .main-nav > a { color: var(--gray); }
.site-header.scrolled .main-nav > a:hover { color: var(--blue-600); }
.main-nav > a.active { color: var(--blue-500); }
.main-nav > a.active::after { width: 100%; }
.site-header:not(.scrolled) .main-nav > a.active { color: var(--blue-200); }

.nav-download {
  padding: 9px 22px !important;
  border-radius: 999px;
  color: #fff !important;
  background: linear-gradient(135deg, var(--blue-300), var(--blue-600));
  box-shadow: 0 8px 20px rgba(31, 127, 204, .4);
}
.nav-download::after { display: none; }
.nav-download:hover { transform: translateY(-2px); }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
}
.nav-toggle span {
  width: 24px; height: 2px;
  border-radius: 2px;
  background: #fff;
  transition: background .3s, transform .3s, opacity .3s;
}
.site-header.scrolled .nav-toggle span { background: var(--ink); }

/* ============================================================
   首屏 Hero
   ============================================================ */
.hero {
  position: relative;
  padding: 168px 0 110px;
  background:
    radial-gradient(1100px 600px at 78% -10%, rgba(79, 174, 240, .55), transparent 60%),
    radial-gradient(900px 560px at 8% 110%, rgba(52, 151, 230, .35), transparent 60%),
    linear-gradient(160deg, var(--navy-900) 0%, var(--navy-800) 42%, var(--navy-700) 100%);
  color: #fff;
  overflow: hidden;
}
.hero-bg { position: absolute; inset: 0; pointer-events: none; }
.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(70px);
  opacity: .55;
}
.blob-1 { width: 380px; height: 380px; right: -90px; top: 90px;  background: rgba(79, 174, 240, .5); }
.blob-2 { width: 300px; height: 300px; left: -110px; bottom: -60px; background: rgba(52, 151, 230, .45); }
.blob-3 { width: 180px; height: 180px; left: 46%; top: 12%; background: rgba(179, 220, 251, .28); }
.grid-mask {
  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: 56px 56px;
  mask-image: radial-gradient(ellipse 80% 70% at 50% 30%, #000 30%, transparent 75%);
}

.hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  gap: 60px;
  align-items: center;
}
.hero-badge {
  display: inline-block;
  padding: 7px 18px;
  border-radius: 999px;
  font-size: 13px;
  letter-spacing: 1px;
  color: var(--blue-100);
  background: rgba(127, 192, 243, .14);
  border: 1px solid rgba(127, 192, 243, .35);
  margin-bottom: 24px;
}
.hero-text h1 {
  font-size: clamp(32px, 4.4vw, 52px);
  line-height: 1.22;
  font-weight: 800;
  letter-spacing: 1px;
}
.hero-text h1 .hl {
  background: linear-gradient(120deg, #bfe2fd, #5eafff);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-desc {
  margin: 22px 0 28px;
  font-size: 16.5px;
  line-height: 1.9;
  color: rgba(233, 243, 252, .86);
  max-width: 560px;
}
.hero-meta { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 32px; }
.meta-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border-radius: 999px;
  font-size: 13.5px;
  color: rgba(233, 243, 252, .9);
  background: rgba(255, 255, 255, .08);
  border: 1px solid rgba(255, 255, 255, .14);
}
.meta-chip strong { color: #fff; font-weight: 700; }
.meta-chip .ico {
  display: inline-grid;
  place-items: center;
  width: 20px; height: 20px;
  border-radius: 6px;
  font-size: 11px;
  font-style: normal;
  color: #fff;
  background: linear-gradient(135deg, var(--blue-300), var(--blue-600));
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 16px; }
.hero-stats {
  display: flex;
  gap: 38px;
  margin-top: 46px;
  padding-top: 28px;
  border-top: 1px solid rgba(255, 255, 255, .12);
}
.hero-stats li { display: flex; flex-direction: column; }
.hero-stats strong {
  font-size: 26px;
  font-weight: 800;
  background: linear-gradient(120deg, #fff, var(--blue-200));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-stats span { font-size: 13px; color: rgba(233, 243, 252, .65); margin-top: 2px; }

/* ---------- 三张截图叠加 + 悬停前置 ---------- */
.hero-shots {
  position: relative;
  height: 500px;
  perspective: 1200px;
}
.shot {
  position: absolute;
  top: 26px;
  width: 248px;
  height: 418px;
  margin: 0;
  border-radius: 22px;
  overflow: hidden;
  cursor: pointer;
  background:
    linear-gradient(160deg, rgba(255,255,255,.16), rgba(255,255,255,.04)),
    linear-gradient(150deg, #6cb6ef, #2b7dc6 70%, #1d5f9e);
  border: 1px solid rgba(255, 255, 255, .28);
  box-shadow: 0 24px 55px rgba(5, 22, 42, .5);
  transition: transform .5s var(--ease), opacity .4s, box-shadow .5s var(--ease), filter .4s;
  will-change: transform;
}
/* img 留空时的占位图标 */
.shot::before {
  content: "";
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none'%3E%3Crect x='3' y='4' width='18' height='16' rx='2.5' stroke='white' stroke-width='1.4' opacity='.55'/%3E%3Ccircle cx='8.6' cy='9.6' r='1.7' fill='white' opacity='.55'/%3E%3Cpath d='M4.5 17.5 10 12l4 3.6 2.2-2.2 3.3 4.1' stroke='white' stroke-width='1.4' stroke-linejoin='round' opacity='.55'/%3E%3C/svg%3E") center 42% / 58px 58px no-repeat;
  pointer-events: none;
}
.shot img {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  object-fit: cover;
  transition: opacity .35s;
}
.shot img.is-empty { opacity: 0; }
.shot figcaption {
  position: absolute;
  left: 50%; bottom: 18px;
  transform: translateX(-50%);
  padding: 6px 16px;
  border-radius: 999px;
  font-size: 12.5px;
  color: #fff;
  white-space: nowrap;
  background: rgba(12, 36, 64, .42);
  border: 1px solid rgba(255, 255, 255, .25);
  backdrop-filter: blur(6px);
}
.shot-1 { left: 6%;  transform: rotate(-9deg) translateY(14px); z-index: 1; }
.shot-2 { left: 50%; transform: translateX(-50%) rotate(0deg) scale(1.06); z-index: 3; }
.shot-3 { right: 6%; transform: rotate(9deg) translateY(14px); z-index: 1; }

/* 悬停容器：非当前图后退变淡 */
.hero-shots:hover .shot { opacity: .65; filter: saturate(.8); }
.hero-shots .shot:hover,
.hero-shots .shot.is-active {
  opacity: 1 !important;
  filter: none;
  transform: translateX(0) translateY(-14px) rotate(0deg) scale(1.07);
  z-index: 5;
  box-shadow: 0 34px 70px rgba(5, 22, 42, .6), 0 0 0 6px rgba(255,255,255,.12);
}
.hero-shots .shot-2:hover,
.hero-shots .shot-2.is-active { transform: translateX(-50%) translateY(-14px) rotate(0deg) scale(1.12); }

.shot-dots {
  position: absolute;
  left: 0; right: 0; bottom: -6px;
  display: flex;
  justify-content: center;
  gap: 9px;
  z-index: 6;
}
.shot-dots span {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: rgba(255, 255, 255, .35);
  cursor: pointer;
  transition: all .3s;
}
.shot-dots span.on { width: 24px; border-radius: 999px; background: var(--blue-300); }

/* ============================================================
   通用 Section
   ============================================================ */
.section { padding: 104px 0; }
.section-alt { background: var(--bg); }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 60px; }
.section-tag {
  display: inline-block;
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 3px;
  color: var(--blue-600);
  background: var(--blue-50);
  padding: 6px 16px;
  border-radius: 999px;
  margin-bottom: 18px;
}
.section-head h2 {
  font-size: clamp(26px, 3.2vw, 38px);
  font-weight: 800;
  color: var(--ink);
}
.section-head p { color: var(--gray); margin-top: 12px; font-size: 16px; }

/* ---------- 功能卡片 ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}
.feature-card {
  position: relative;
  padding: 36px 30px 32px;
  border-radius: var(--radius-lg);
  background: #fff;
  border: 1px solid var(--line);
  box-shadow: var(--shadow-sm);
  transition: transform .35s var(--ease), box-shadow .35s, border-color .35s;
  overflow: hidden;
}
.feature-card::after {
  content: "";
  position: absolute;
  right: -50px; top: -50px;
  width: 130px; height: 130px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--blue-100), transparent 70%);
  opacity: 0;
  transition: opacity .35s;
}
.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow);
  border-color: var(--blue-200);
}
.feature-card:hover::after { opacity: 1; }
.feature-ico {
  display: grid;
  place-items: center;
  width: 58px; height: 58px;
  border-radius: 16px;
  font-size: 24px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 22px;
  box-shadow: 0 10px 22px rgba(31, 127, 204, .3);
}
.f-ico-1 { background: linear-gradient(135deg, #52abec, var(--blue-600)); }
.f-ico-2 { background: linear-gradient(135deg, #46b8c8, #23809e); }
.f-ico-3 { background: linear-gradient(135deg, #5a8dee, #3460c4); }
.f-ico-4 { background: linear-gradient(135deg, #f08ab4, #d35d8c); }
.f-ico-5 { background: linear-gradient(135deg, #e8a44f, #cf7c1e); }
.f-ico-6 { background: linear-gradient(135deg, #58c38c, #28925d); }
.feature-card h3 { font-size: 19px; margin-bottom: 10px; }
.feature-card p { font-size: 14.5px; color: var(--gray); }

/* ---------- 用户评价 ---------- */
.review-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.review-card {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 28px 28px 26px;
  border: 1px solid var(--line);
  box-shadow: var(--shadow-sm);
  transition: transform .35s var(--ease), box-shadow .35s;
}
.review-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); }
.review-top { display: flex; align-items: center; gap: 14px; margin-bottom: 16px; }
.review-top strong { display: block; font-size: 15.5px; }
.stars { font-size: 13px; color: #f5a623; letter-spacing: 2px; }
.review-card p { font-size: 14.5px; color: var(--gray); }

/* 汉字头像（不使用 img） */
.avatar {
  width: 46px; height: 46px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-size: 19px;
  font-weight: 700;
  color: #fff;
  flex: none;
  box-shadow: inset 0 1px 0 rgba(255,255,255,.35), 0 6px 14px rgba(16,53,92,.18);
}
.av-1 { background: linear-gradient(135deg, #f48fb1, #e04f88); }
.av-2 { background: linear-gradient(135deg, #52abec, #1f7fcc); }
.av-3 { background: linear-gradient(135deg, #7e8cf5, #4c5bd4); }
.av-4 { background: linear-gradient(135deg, #ffb36b, #ef8a2c); }
.av-5 { background: linear-gradient(135deg, #58c38c, #1f9e6a); }
.av-6 { background: linear-gradient(135deg, #46c0c9, #1b8a9c); }

/* ---------- FAQ ---------- */
.faq-list { display: flex; flex-direction: column; gap: 14px; }
.faq-item {
  border: 1px solid var(--line);
  border-radius: 16px;
  background: #fff;
  overflow: hidden;
  transition: border-color .3s, box-shadow .3s;
}
.faq-item.open { border-color: var(--blue-200); box-shadow: var(--shadow-sm); }
.faq-q {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 24px;
  font-size: 16px;
  font-weight: 600;
  color: var(--ink);
  text-align: left;
}
.faq-arrow {
  position: relative;
  width: 14px; height: 14px;
  flex: none;
}
.faq-arrow::before,
.faq-arrow::after {
  content: "";
  position: absolute;
  top: 50%; left: 50%;
  background: var(--blue-500);
  border-radius: 2px;
  transition: transform .3s var(--ease);
}
.faq-arrow::before { width: 14px; height: 2px; transform: translate(-50%, -50%); }
.faq-arrow::after  { width: 2px; height: 14px; transform: translate(-50%, -50%); }
.faq-item.open .faq-arrow::after { transform: translate(-50%, -50%) rotate(90deg); opacity: 0; }
.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height .4s var(--ease);
}
.faq-a p {
  padding: 0 24px 22px;
  font-size: 14.5px;
  color: var(--gray);
}

/* ============================================================
   下载区域
   ============================================================ */
.download {
  position: relative;
  padding: 110px 0;
  background:
    radial-gradient(900px 480px at 85% 0%, rgba(127, 192, 243, .35), transparent 60%),
    linear-gradient(155deg, var(--navy-900), var(--navy-800) 55%, var(--blue-700));
  overflow: hidden;
}
.download-bg {
  position: absolute; inset: 0;
  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: 56px 56px;
  mask-image: radial-gradient(ellipse 70% 80% at 50% 50%, #000 20%, transparent 80%);
}
.download-card {
  position: relative;
  max-width: 760px;
  margin: 0 auto;
  text-align: center;
  padding: 64px 40px 56px;
  border-radius: 32px;
  color: #fff;
  background: linear-gradient(160deg, rgba(255,255,255,.12), rgba(255,255,255,.04));
  border: 1px solid rgba(255,255,255,.18);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-lg);
}
.download-card .logo-mark { margin: 0 auto 24px; }
.download-card h2 { font-size: clamp(24px, 3vw, 34px); line-height: 1.35; }
.download-card > p { color: rgba(233,243,252,.8); margin-top: 12px; }
.download-meta {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  margin: 26px 0 36px;
  font-size: 14.5px;
  color: rgba(233,243,252,.85);
}
.download-meta strong { color: #fff; }
.download-meta i {
  width: 4px; height: 4px;
  border-radius: 50%;
  background: rgba(255,255,255,.4);
}
.btn-download {
  font-size: 18px;
  padding: 18px 54px;
  color: var(--blue-700);
  background: linear-gradient(135deg, #ffffff, #dcedfc);
  box-shadow: 0 16px 40px rgba(0, 0, 0, .3), inset 0 1px 0 #fff;
  animation: pulse 2.4s ease-in-out infinite;
}
.btn-download .btn-ico { background: var(--blue-50); color: var(--blue-600); font-size: 15px; }
.btn-download:hover {
  transform: translateY(-4px) scale(1.03);
  box-shadow: 0 24px 55px rgba(0, 0, 0, .4), inset 0 1px 0 #fff;
}
@keyframes pulse {
  0%, 100% { box-shadow: 0 16px 40px rgba(0,0,0,.3), 0 0 0 0 rgba(127,192,243,.5); }
  50%      { box-shadow: 0 16px 40px rgba(0,0,0,.3), 0 0 0 16px rgba(127,192,243,0); }
}
.download-tip { margin-top: 20px; font-size: 13px; color: rgba(233,243,252,.55); }

/* 下载按钮：href 为空时的提示气泡 */
.btn-download { position: relative; }
.btn-download::after {
  content: "下载地址即将开放，敬请期待";
  position: absolute;
  bottom: calc(100% + 14px);
  left: 50%;
  transform: translateX(-50%) translateY(8px);
  white-space: nowrap;
  padding: 10px 22px;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 500;
  color: #fff;
  background: rgba(12, 36, 64, .94);
  box-shadow: 0 8px 24px rgba(0, 0, 0, .3);
  opacity: 0;
  pointer-events: none;
  transition: opacity .3s var(--ease), transform .3s var(--ease);
  z-index: 10;
}
.btn-download::before {
  content: "";
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%);
  border: 6px solid transparent;
  border-top-color: rgba(12, 36, 64, .94);
  opacity: 0;
  pointer-events: none;
  transition: opacity .3s var(--ease);
  z-index: 10;
}
.btn-download.show-tip::after { opacity: 1; transform: translateX(-50%) translateY(0); }
.btn-download.show-tip::before { opacity: 1; }

/* ============================================================
   页脚
   ============================================================ */
.site-footer {
  background: var(--navy-900);
  color: rgba(233, 243, 252, .75);
  padding: 56px 0 28px;
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
  flex-wrap: wrap;
  padding-bottom: 30px;
  border-bottom: 1px solid rgba(255,255,255,.1);
}
.footer-brand { display: flex; align-items: center; gap: 14px; }
.footer-brand strong { display: block; font-size: 17px; color: #fff; }
.footer-brand strong em { font-style: normal; font-size: 12px; font-weight: 400; color: var(--blue-200); margin-left: 6px; }
.footer-brand span:last-child { font-size: 13.5px; }
.footer-nav { display: flex; gap: 26px; flex-wrap: wrap; }
.footer-nav a { font-size: 14px; transition: color .25s; }
.footer-nav a:hover { color: #fff; }
.footer-copy {
  padding-top: 24px;
  font-size: 13px;
  color: rgba(233, 243, 252, .45);
  text-align: center;
}

/* ---------- 返回顶部 ---------- */
.back-top {
  position: fixed;
  right: 26px; bottom: 26px;
  width: 48px; height: 48px;
  border-radius: 50%;
  font-size: 20px;
  color: #fff;
  background: linear-gradient(135deg, var(--blue-300), var(--blue-600));
  box-shadow: 0 10px 26px rgba(31, 127, 204, .45);
  opacity: 0;
  visibility: hidden;
  transform: translateY(14px);
  transition: all .3s var(--ease);
  z-index: 90;
}
.back-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
.back-top:hover { transform: translateY(-3px); }

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

/* ============================================================
   自适应
   ============================================================ */
@media (max-width: 1024px) {
  .hero-inner { grid-template-columns: 1fr; gap: 50px; }
  .hero { padding: 140px 0 90px; }
  .hero-text { text-align: center; }
  .hero-desc { margin-left: auto; margin-right: auto; }
  .hero-meta, .hero-actions { justify-content: center; }
  .hero-stats { justify-content: center; }
  .hero-shots { max-width: 480px; margin: 0 auto; width: 100%; }
  .feature-grid, .review-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 860px) {
  .main-nav {
    position: absolute;
    top: 100%;
    left: 4%; right: 4%;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: 14px;
    border-radius: 18px;
    background: rgba(255,255,255,.98);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all .3s var(--ease);
  }
  .main-nav.open { opacity: 1; visibility: visible; transform: translateY(6px); }
  .main-nav > a {
    color: var(--gray) !important;
    padding: 12px 16px;
    border-radius: 12px;
  }
  .main-nav > a::after { display: none; }
  .main-nav > a:hover, .main-nav > a.active { background: var(--blue-50); color: var(--blue-600) !important; }
  .nav-download {
    text-align: center;
    color: #fff !important;
    background: linear-gradient(135deg, var(--blue-300), var(--blue-600)) !important;
  }
  .main-nav > a.nav-download:hover,
  .main-nav > a.nav-download.active {
    background: linear-gradient(135deg, var(--blue-300), var(--blue-600)) !important;
    color: #fff !important;
  }
  .nav-toggle { display: flex; }
  .nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav-toggle.open span:nth-child(2) { opacity: 0; }
  .nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
}

@media (max-width: 680px) {
  .section { padding: 76px 0; }
  .download { padding: 80px 0; }
  .feature-grid, .review-grid { grid-template-columns: 1fr; }
  .hero-shots { height: 400px; }
  .shot { width: 196px; height: 330px; top: 20px; border-radius: 18px; }
  .shot::before { background-size: 46px 46px; }
  .shot figcaption { font-size: 11.5px; padding: 5px 12px; }
  .hero-stats { gap: 26px; }
  .hero-stats strong { font-size: 22px; }
  .download-card { padding: 48px 22px 42px; }
  .btn-download { padding: 16px 40px; font-size: 16.5px; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 380px) {
  .hero-shots { height: 350px; }
  .shot { width: 168px; height: 286px; }
}

/* 降低动效偏好 */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}