/* ============================================================
   MPC-HC 中文官网  www.mpc-hc.cn
   配色源自品牌 Logo：场记板墨黑 + 纯净白 + 品牌蓝
   风格：扁平 · 现代 · 专业
   ============================================================ */

:root {
  --brand:        #4A91E2;
  --brand-dark:   #3578C9;
  --brand-deep:   #2B6CB0;
  --brand-tint:   #EAF2FD;
  --ink:          #14181D;
  --ink-2:        #232A32;
  --body:         #434B57;
  --muted:        #6B7482;
  --bg:           #FFFFFF;
  --bg-soft:      #F5F7FA;
  --bg-dark:      #14181D;
  --border:       #E3E8EF;
  --radius:       14px;
  --radius-sm:    10px;
  --shadow-sm:    0 1px 2px rgba(20,24,29,.05), 0 4px 16px rgba(20,24,29,.06);
  --shadow-md:    0 6px 24px rgba(20,24,29,.10), 0 2px 6px rgba(20,24,29,.06);
  --container:    1180px;
  --font: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

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

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.7;
  color: var(--body);
  background: var(--bg);
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: var(--brand-deep); text-decoration: none; transition: color .2s ease; }
a:hover { color: var(--brand); }
ul, ol { list-style-position: inside; }

h1, h2, h3, h4 { color: var(--ink); line-height: 1.3; font-weight: 700; }

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

.section { padding: 88px 0; }
.section-soft { background: var(--bg-soft); }

.section-head { text-align: center; max-width: 720px; margin: 0 auto 56px; }
.section-eyebrow {
  display: inline-block; font-size: 13px; font-weight: 700; letter-spacing: 2px;
  color: var(--brand-deep); text-transform: uppercase; margin-bottom: 12px;
}
.section-head h2 { font-size: 34px; margin-bottom: 14px; }
.section-head p { color: var(--muted); font-size: 17px; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 13px 28px; border-radius: 10px; font-size: 16px; font-weight: 600;
  border: 1px solid transparent; cursor: pointer; transition: all .2s ease;
  font-family: var(--font); line-height: 1.4; white-space: nowrap;
}
.btn svg { flex: none; }
.btn-brand { background: var(--brand); color: #fff; }
.btn-brand:hover { background: var(--brand-dark); color: #fff; transform: translateY(-1px); }
.btn-dark { background: var(--ink); color: #fff; }
.btn-dark:hover { background: var(--ink-2); color: #fff; transform: translateY(-1px); }
.btn-ghost { background: #fff; color: var(--ink); border-color: var(--border); }
.btn-ghost:hover { border-color: var(--brand); color: var(--brand-deep); }
.btn-lg { padding: 16px 36px; font-size: 17px; border-radius: 12px; }
.btn-sm { padding: 9px 18px; font-size: 14px; }
.btn-block { width: 100%; }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.92); backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.header-inner { display: flex; align-items: center; height: 68px; gap: 32px; }
.brand { display: flex; align-items: center; gap: 10px; flex: none; }
.brand img { width: 36px; height: 36px; }
.brand-name { font-size: 20px; font-weight: 800; color: var(--ink); letter-spacing: .3px; }
.brand-name span { color: var(--brand); }
.main-nav { display: flex; gap: 6px; margin-left: auto; }
.main-nav a {
  padding: 8px 16px; border-radius: 8px; color: var(--body);
  font-size: 15px; font-weight: 500;
}
.main-nav a:hover { color: var(--brand-deep); background: var(--brand-tint); }
.main-nav a.active { color: var(--brand-deep); background: var(--brand-tint); font-weight: 600; }
.header-cta { flex: none; }
.nav-toggle {
  display: none; background: none; border: none; cursor: pointer; padding: 8px;
  margin-left: auto;
}
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--ink); margin: 5px 0; border-radius: 2px; transition: .25s; }
.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); }

/* ---------- 首页 Hero ---------- */
.hero {
  position: relative; overflow: hidden;
  background: linear-gradient(160deg, #F4F8FE 0%, #FFFFFF 55%, #F7FAFD 100%);
  padding: 76px 0 90px;
}
.hero::before {
  content: ""; position: absolute; right: -180px; top: -180px; width: 560px; height: 560px;
  background: radial-gradient(circle, rgba(74,145,226,.14), transparent 65%);
}
.hero-inner { display: grid; grid-template-columns: 1.05fr 1fr; gap: 64px; align-items: center; position: relative; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  background: #fff; border: 1px solid var(--border); border-radius: 999px;
  padding: 6px 16px 6px 8px; font-size: 13.5px; font-weight: 600; color: var(--ink);
  box-shadow: var(--shadow-sm); margin-bottom: 22px;
}
.hero-badge .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--brand); margin-left: 6px; }
.hero h1 { font-size: 48px; letter-spacing: -.5px; margin-bottom: 20px; }
.hero h1 em { font-style: normal; color: var(--brand); }
.hero-sub { font-size: 18px; color: var(--muted); max-width: 520px; margin-bottom: 34px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; align-items: center; }
.hero-meta { margin-top: 22px; font-size: 14px; color: var(--muted); display: flex; gap: 18px; flex-wrap: wrap; }
.hero-meta b { color: var(--ink); font-weight: 600; }
.hero-meta i { font-style: normal; margin-right: 4px; }

/* Hero 播放器示意（纯 CSS 扁平绘制） */
.player-mock {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  box-shadow: var(--shadow-md); overflow: hidden;
}
.pm-titlebar {
  display: flex; align-items: center; gap: 10px; padding: 11px 16px;
  background: var(--ink); color: #cfd6dd; font-size: 13px;
}
.pm-titlebar .pm-logo { width: 18px; height: 18px; border-radius: 4px; }
.pm-titlebar .pm-dots { margin-left: auto; display: flex; gap: 7px; }
.pm-titlebar .pm-dots i { width: 10px; height: 10px; border-radius: 50%; background: #3A434D; }
.pm-screen {
  background: #0B0E12; aspect-ratio: 16 / 9; display: flex;
  align-items: center; justify-content: center; position: relative;
}
.pm-screen img { width: 84px; opacity: .92; filter: drop-shadow(0 6px 18px rgba(74,145,226,.35)); }
.pm-screen .pm-res {
  position: absolute; top: 12px; right: 14px; font-size: 11px; color: #8FA8C8;
  border: 1px solid rgba(143,168,200,.35); padding: 2px 8px; border-radius: 6px;
}
.pm-seek { padding: 12px 16px 4px; display: flex; align-items: center; gap: 10px; font-size: 12px; color: var(--muted); }
.pm-seek .bar { flex: 1; height: 5px; background: var(--border); border-radius: 3px; position: relative; }
.pm-seek .bar::after { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 42%; background: var(--brand); border-radius: 3px; }
.pm-seek .bar .knob { position: absolute; left: 42%; top: 50%; transform: translate(-50%,-50%); width: 13px; height: 13px; background: #fff; border: 3px solid var(--brand); border-radius: 50%; }
.pm-controls { display: flex; align-items: center; gap: 6px; padding: 10px 14px 14px; }
.pm-controls .pc-btn {
  width: 36px; height: 36px; border-radius: 8px; display: flex; align-items: center; justify-content: center;
  color: var(--ink-2);
}
.pm-controls .pc-btn:hover { background: var(--bg-soft); }
.pm-controls .pc-play { background: var(--brand); color: #fff; width: 42px; height: 42px; border-radius: 10px; }
.pm-controls .pc-space { flex: 1; }
.pm-controls .pc-time { font-size: 12.5px; color: var(--muted); font-variant-numeric: tabular-nums; margin-right: 6px; }

/* ---------- 信任条 ---------- */
.trust-bar { border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); background: #fff; }
.trust-inner { display: grid; grid-template-columns: repeat(4, 1fr); }
.trust-item {
  display: flex; align-items: center; gap: 14px; padding: 26px 20px;
  border-left: 1px solid var(--border);
}
.trust-item:first-child { border-left: none; }
.trust-item .t-ico {
  width: 46px; height: 46px; flex: none; border-radius: 12px;
  background: var(--brand-tint); color: var(--brand-deep);
  display: flex; align-items: center; justify-content: center;
}
.trust-item h3 { font-size: 16px; margin-bottom: 2px; }
.trust-item p { font-size: 13.5px; color: var(--muted); line-height: 1.5; }

/* ---------- 特性卡片 ---------- */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 30px 28px; transition: transform .25s ease, box-shadow .25s ease, border-color .25s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: #D5E4F7; }
.card .c-ico {
  width: 52px; height: 52px; border-radius: 13px; margin-bottom: 18px;
  background: var(--brand-tint); color: var(--brand-deep);
  display: flex; align-items: center; justify-content: center;
}
.card h3 { font-size: 19px; margin-bottom: 10px; }
.card p { font-size: 15px; color: var(--muted); }

/* ---------- 使用场景 ---------- */
.scene-card { overflow: hidden; padding: 0; display: flex; flex-direction: column; }
.scene-visual {
  height: 150px; display: flex; align-items: center; justify-content: center;
  color: #fff; position: relative;
}
.scene-visual::after {
  content: ""; position: absolute; inset: 0;
  background-image: radial-gradient(rgba(255,255,255,.18) 1px, transparent 1px);
  background-size: 18px 18px;
}
.scene-visual svg { position: relative; z-index: 1; }
.sv-1 { background: linear-gradient(135deg, #2B6CB0, #4A91E2); }
.sv-2 { background: linear-gradient(135deg, #14181D, #3A4756); }
.sv-3 { background: linear-gradient(135deg, #3578C9, #6FB0F0); }
.sv-4 { background: linear-gradient(135deg, #232A32, #4A91E2); }
.sv-5 { background: linear-gradient(135deg, #4A91E2, #9CC4F2); }
.sv-6 { background: linear-gradient(135deg, #1E4E86, #3578C9); }
.scene-body { padding: 24px 26px 28px; }
.scene-body h3 { font-size: 18px; margin-bottom: 8px; }
.scene-body p { font-size: 14.5px; color: var(--muted); }

/* ---------- 数据统计带 ---------- */
.stats-band { background: var(--bg-dark); color: #fff; }
.stats-inner { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; padding: 64px 0; text-align: center; }
.stat .num { font-size: 42px; font-weight: 800; color: #fff; letter-spacing: -.5px; }
.stat .num em { font-style: normal; color: var(--brand); }
.stat .lbl { color: #9AA5B1; font-size: 15px; margin-top: 6px; }

/* ---------- 用户评价 ---------- */
.review-viewport { overflow: hidden; }
.review-track { display: flex; transition: transform .5s ease; }
.review-slide { flex: 0 0 100%; padding: 4px; }
.review-card {
  max-width: 780px; margin: 0 auto; background: #fff; border: 1px solid var(--border);
  border-radius: var(--radius); padding: 40px 44px; text-align: center; box-shadow: var(--shadow-sm);
}
.review-stars { color: #F5A623; letter-spacing: 4px; font-size: 18px; margin-bottom: 16px; }
.review-text { font-size: 19px; color: var(--ink-2); line-height: 1.8; margin-bottom: 24px; }
.review-text::before { content: "“"; color: var(--brand); }
.review-text::after { content: "”"; color: var(--brand); }
.review-author { display: flex; align-items: center; justify-content: center; gap: 12px; }
.review-avatar {
  width: 46px; height: 46px; border-radius: 50%; background: var(--brand-tint);
  color: var(--brand-deep); font-weight: 700; display: flex; align-items: center; justify-content: center; font-size: 17px;
}
.review-author .who { text-align: left; }
.review-author .who b { display: block; color: var(--ink); font-size: 15px; }
.review-author .who span { font-size: 13px; color: var(--muted); }
.review-dots { display: flex; justify-content: center; gap: 10px; margin-top: 28px; }
.review-dots button {
  width: 10px; height: 10px; border-radius: 50%; border: none; cursor: pointer;
  background: #CBD5E1; transition: .25s; padding: 0;
}
.review-dots button.active { background: var(--brand); width: 26px; border-radius: 6px; }

/* ---------- CTA 横幅 ---------- */
.cta-band {
  background: linear-gradient(135deg, var(--brand-deep), var(--brand));
  border-radius: 20px; padding: 64px 56px; color: #fff;
  display: flex; align-items: center; justify-content: space-between; gap: 40px; flex-wrap: wrap;
}
.cta-band h2 { color: #fff; font-size: 32px; margin-bottom: 10px; }
.cta-band p { color: rgba(255,255,255,.85); font-size: 16px; max-width: 560px; }
.cta-band .btn-light { background: #fff; color: var(--brand-deep); }
.cta-band .btn-light:hover { background: #F0F6FE; color: var(--brand-dark); transform: translateY(-1px); }

/* ---------- 页头横幅（子页） ---------- */
.page-hero { background: linear-gradient(160deg, #F4F8FE, #FFFFFF); padding: 72px 0 64px; border-bottom: 1px solid var(--border); }
.page-hero h1 { font-size: 40px; margin-bottom: 14px; }
.page-hero .crumb { font-size: 14px; color: var(--muted); margin-bottom: 18px; }
.page-hero .crumb a { color: var(--muted); }
.page-hero .crumb a:hover { color: var(--brand); }
.page-hero .lead { font-size: 17px; color: var(--muted); max-width: 680px; }

/* ---------- 下载中心 ---------- */
.dl-layout { display: grid; grid-template-columns: 1.5fr 1fr; gap: 28px; align-items: start; }
.dl-card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 32px; position: relative;
}
.dl-card.recommend { border-color: var(--brand); box-shadow: var(--shadow-md); }
.dl-flag {
  position: absolute; top: -13px; left: 28px; background: var(--brand); color: #fff;
  font-size: 12.5px; font-weight: 700; padding: 4px 14px; border-radius: 999px; letter-spacing: 1px;
}
.dl-card h3 { font-size: 22px; margin-bottom: 6px; }
.dl-card .dl-desc { color: var(--muted); font-size: 14.5px; margin-bottom: 22px; }
.dl-spec { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px 20px; margin-bottom: 26px; }
.dl-spec div { font-size: 14px; }
.dl-spec b { display: block; color: var(--ink); font-size: 15px; }
.dl-spec span { color: var(--muted); }
.dl-qr-side { text-align: center; }
.dl-qr-side img { width: 168px; margin: 6px auto 12px; border: 1px solid var(--border); border-radius: 12px; padding: 8px; }
.dl-qr-side h4 { font-size: 16px; margin-bottom: 4px; }
.dl-qr-side p { font-size: 13px; color: var(--muted); }

.steps { counter-reset: step; display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.step {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 30px 26px;
  position: relative;
}
.step::before {
  counter-increment: step; content: counter(step);
  display: flex; align-items: center; justify-content: center;
  width: 40px; height: 40px; border-radius: 11px; background: var(--ink); color: #fff;
  font-weight: 800; font-size: 18px; margin-bottom: 18px;
}
.step h3 { font-size: 17px; margin-bottom: 8px; }
.step p { font-size: 14.5px; color: var(--muted); }

.changelog { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.changelog-item { padding: 24px 30px; border-top: 1px solid var(--border); }
.changelog-item:first-child { border-top: none; }
.changelog-item .cl-head { display: flex; align-items: baseline; gap: 14px; flex-wrap: wrap; margin-bottom: 8px; }
.changelog-item h3 { font-size: 17px; }
.changelog-item .cl-date { font-size: 13.5px; color: var(--muted); }
.changelog-item .tag-new { background: var(--brand-tint); color: var(--brand-deep); font-size: 12px; font-weight: 700; padding: 2px 10px; border-radius: 999px; }
.changelog-item ul { list-style: none; }
.changelog-item li { font-size: 14.5px; color: var(--body); padding-left: 20px; position: relative; margin: 4px 0; }
.changelog-item li::before { content: ""; position: absolute; left: 4px; top: 11px; width: 6px; height: 6px; border-radius: 2px; background: var(--brand); }

/* ---------- 特性详情页 ---------- */
.feat-block { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; margin-bottom: 88px; }
.feat-block:last-child { margin-bottom: 0; }
.feat-block.flip .feat-visual { order: -1; }
.feat-visual {
  border-radius: var(--radius); border: 1px solid var(--border);
  background: linear-gradient(150deg, #F4F8FE, #FFFFFF);
  min-height: 300px; display: flex; align-items: center; justify-content: center;
  box-shadow: var(--shadow-sm); padding: 40px; color: var(--brand-deep);
}
.feat-block h2 { font-size: 28px; margin-bottom: 16px; }
.feat-block .lead { color: var(--muted); margin-bottom: 20px; }
.check-list { list-style: none; }
.check-list li { display: flex; gap: 12px; margin: 12px 0; font-size: 15.5px; color: var(--body); }
.check-list svg { flex: none; margin-top: 4px; color: var(--brand); }
.check-list b { color: var(--ink); }

.format-cloud { display: flex; flex-wrap: wrap; gap: 10px; }
.format-cloud span {
  background: #fff; border: 1px solid var(--border); border-radius: 8px;
  padding: 7px 14px; font-size: 13.5px; color: var(--ink-2); font-weight: 500;
  font-family: "Consolas", "Monaco", monospace; text-transform: uppercase;
}
.format-group { margin-bottom: 34px; }
.format-group h3 { font-size: 17px; margin-bottom: 14px; display: flex; align-items: center; gap: 10px; }
.format-group h3 svg { color: var(--brand-deep); }

.spec-table { width: 100%; border-collapse: collapse; background: #fff; border-radius: var(--radius); overflow: hidden; border: 1px solid var(--border); }
.spec-table th, .spec-table td { padding: 16px 22px; text-align: left; font-size: 15px; border-bottom: 1px solid var(--border); }
.spec-table tr:last-child th, .spec-table tr:last-child td { border-bottom: none; }
.spec-table th { width: 220px; color: var(--muted); font-weight: 500; background: var(--bg-soft); }
.spec-table td { color: var(--ink); font-weight: 500; }

/* ---------- 使用指南 ---------- */
.guide-layout { display: grid; grid-template-columns: 230px 1fr; gap: 48px; align-items: start; }
.guide-side { position: sticky; top: 92px; border: 1px solid var(--border); border-radius: var(--radius); background: #fff; padding: 14px; }
.guide-side a { display: block; padding: 10px 14px; border-radius: 8px; color: var(--body); font-size: 14.5px; font-weight: 500; }
.guide-side a:hover, .guide-side a.active { background: var(--brand-tint); color: var(--brand-deep); }
.guide-content h2 { font-size: 26px; margin-bottom: 18px; padding-top: 8px; }
.guide-content section { margin-bottom: 64px; scroll-margin-top: 90px; }
.guide-content p { margin-bottom: 14px; }
.guide-content .tip {
  background: var(--brand-tint); border-left: 4px solid var(--brand); border-radius: 0 10px 10px 0;
  padding: 16px 20px; font-size: 14.5px; color: var(--ink-2); margin: 18px 0;
}
.guide-content .tip b { color: var(--brand-deep); }

.kbd-table { width: 100%; border-collapse: collapse; background: #fff; border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.kbd-table th, .kbd-table td { padding: 13px 20px; text-align: left; font-size: 14.5px; border-bottom: 1px solid var(--border); }
.kbd-table thead th { background: var(--ink); color: #fff; font-weight: 600; }
.kbd-table tbody tr:last-child td { border-bottom: none; }
.kbd-table tbody tr:hover { background: var(--bg-soft); }
kbd {
  display: inline-block; background: var(--bg-soft); border: 1px solid var(--border);
  border-bottom-width: 2px; border-radius: 6px; padding: 2px 9px;
  font-family: "Consolas", monospace; font-size: 13px; color: var(--ink); font-weight: 600;
}

.faq-item { background: #fff; border: 1px solid var(--border); border-radius: var(--radius-sm); margin-bottom: 12px; overflow: hidden; }
.faq-q {
  width: 100%; display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 19px 24px; background: none; border: none; cursor: pointer; text-align: left;
  font-size: 16px; font-weight: 600; color: var(--ink); font-family: var(--font);
}
.faq-q .fq-ico { flex: none; width: 26px; height: 26px; border-radius: 7px; background: var(--brand-tint); color: var(--brand-deep); display: flex; align-items: center; justify-content: center; transition: transform .3s; }
.faq-item.open .fq-ico { transform: rotate(45deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .35s ease; }
.faq-a .faq-a-inner { padding: 0 24px 22px; color: var(--muted); font-size: 15px; }
.faq-a a { font-weight: 600; }

/* ---------- 关于页 ---------- */
.timeline { position: relative; padding-left: 34px; }
.timeline::before { content: ""; position: absolute; left: 8px; top: 6px; bottom: 6px; width: 2px; background: var(--border); }
.tl-item { position: relative; padding-bottom: 34px; }
.tl-item:last-child { padding-bottom: 0; }
.tl-item::before {
  content: ""; position: absolute; left: -32px; top: 5px; width: 14px; height: 14px;
  border-radius: 50%; background: #fff; border: 4px solid var(--brand);
}
.tl-item .tl-year { font-size: 13.5px; font-weight: 700; color: var(--brand-deep); letter-spacing: 1px; }
.tl-item h3 { font-size: 18px; margin: 4px 0 8px; }
.tl-item p { font-size: 15px; color: var(--muted); }

.oss-banner {
  background: var(--bg-dark); border-radius: var(--radius); color: #C9D2DC;
  padding: 44px 48px; display: grid; grid-template-columns: 1.4fr 1fr; gap: 40px; align-items: center;
}
.oss-banner h2 { color: #fff; font-size: 26px; margin-bottom: 12px; }
.oss-banner p { font-size: 15px; }
.oss-banner .oss-links { display: flex; flex-direction: column; gap: 12px; }
.oss-banner .oss-links a {
  display: flex; align-items: center; justify-content: space-between;
  background: rgba(255,255,255,.06); border: 1px solid rgba(255,255,255,.12);
  border-radius: 10px; padding: 14px 18px; color: #fff; font-weight: 600; font-size: 14.5px;
  transition: .2s;
}
.oss-banner .oss-links a:hover { background: rgba(255,255,255,.12); }
.oss-banner .oss-links a span { color: #8FA0B3; font-weight: 400; font-size: 13px; }

/* ---------- 页脚 ---------- */
.site-footer { background: var(--bg-dark); color: #9AA5B1; }
.footer-main { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 40px; padding: 64px 0 48px; }
.footer-brand img { width: 40px; margin-bottom: 16px; }
.footer-brand p { font-size: 14px; max-width: 300px; line-height: 1.8; }
.footer-col h4 { color: #fff; font-size: 15px; margin-bottom: 18px; letter-spacing: 1px; }
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 11px; }
.footer-col a { color: #9AA5B1; font-size: 14.5px; }
.footer-col a:hover { color: #fff; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.08); padding: 22px 0; display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; font-size: 13.5px; }
.footer-bottom a { color: #9AA5B1; }
.footer-bottom a:hover { color: #fff; }

/* ---------- 下载弹窗 ---------- */
.modal { position: fixed; inset: 0; z-index: 1000; display: none; }
.modal.show { display: block; }
.modal-mask { position: absolute; inset: 0; background: rgba(15,20,26,.62); backdrop-filter: blur(4px); animation: fadeIn .25s ease; }
.modal-box {
  position: relative; max-width: 560px; margin: 6vh auto 0; background: #fff;
  border-radius: 18px; padding: 40px 40px 32px; box-shadow: 0 24px 80px rgba(0,0,0,.28);
  animation: popIn .3s cubic-bezier(.2,.9,.3,1.2); max-height: 88vh; overflow-y: auto;
}
@keyframes fadeIn { from { opacity: 0; } }
@keyframes popIn { from { opacity: 0; transform: translateY(24px) scale(.96); } }
.modal-close {
  position: absolute; top: 16px; right: 16px; width: 36px; height: 36px; border-radius: 9px;
  border: none; background: var(--bg-soft); color: var(--muted); font-size: 20px; cursor: pointer;
  line-height: 1; transition: .2s;
}
.modal-close:hover { background: var(--border); color: var(--ink); }
.modal-box h3 { font-size: 24px; text-align: center; margin-bottom: 6px; }
.modal-box h3 em { font-style: normal; color: var(--brand); }
.modal-sub { text-align: center; color: var(--muted); font-size: 14.5px; margin-bottom: 26px; }
.qr-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; margin-bottom: 24px; }
.qr-card { border: 1px solid var(--border); border-radius: 14px; padding: 20px 16px; text-align: center; transition: .2s; }
.qr-card:hover { border-color: var(--brand); box-shadow: var(--shadow-sm); }
.qr-card img { width: 150px; margin: 0 auto 12px; }
.qr-card h4 { font-size: 15.5px; margin-bottom: 3px; }
.qr-card p { font-size: 12.5px; color: var(--muted); }
.modal-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 18px; }
.modal-note { text-align: center; font-size: 13px; color: var(--muted); }
.modal-note a { font-weight: 600; }
body.modal-open { overflow: hidden; }

/* ---------- 返回顶部 ---------- */
.to-top {
  position: fixed; right: 26px; bottom: 26px; width: 46px; height: 46px; border-radius: 12px;
  background: var(--ink); color: #fff; border: none; cursor: pointer; z-index: 90;
  display: flex; align-items: center; justify-content: center; opacity: 0; pointer-events: none;
  transition: .3s; box-shadow: var(--shadow-md);
}
.to-top.show { opacity: 1; pointer-events: auto; }
.to-top:hover { background: var(--brand-deep); }

/* ---------- 滚动渐显（仅在 JS 可用时启用，无 JS 直接显示） ---------- */
html.js .reveal { opacity: 0; transform: translateY(26px); transition: opacity .6s ease, transform .6s ease; }
html.js .reveal.in { opacity: 1; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .hero-inner { grid-template-columns: 1fr; gap: 48px; }
  .hero h1 { font-size: 38px; }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .trust-inner { grid-template-columns: repeat(2, 1fr); }
  .trust-item:nth-child(3) { border-left: none; }
  .trust-item { border-top: 1px solid var(--border); }
  .trust-item:nth-child(-n+2) { border-top: none; }
  .stats-inner { grid-template-columns: repeat(2, 1fr); gap: 40px 16px; }
  .dl-layout, .feat-block, .oss-banner { grid-template-columns: 1fr; }
  .feat-block.flip .feat-visual { order: 0; }
  .feat-block { gap: 32px; margin-bottom: 64px; }
  .footer-main { grid-template-columns: 1fr 1fr; }
  .guide-layout { grid-template-columns: 1fr; }
  .guide-side { position: static; display: flex; flex-wrap: wrap; gap: 6px; }
}
@media (max-width: 768px) {
  .section { padding: 64px 0; }
  .section-head h2 { font-size: 27px; }
  .main-nav {
    display: none; position: absolute; top: 68px; left: 0; right: 0;
    background: #fff; flex-direction: column; padding: 12px 20px 20px; gap: 2px;
    border-bottom: 1px solid var(--border); box-shadow: var(--shadow-md);
  }
  .main-nav.open { display: flex; }
  .main-nav a { padding: 12px 14px; font-size: 16px; }
  .nav-toggle { display: block; }
  .header-cta { display: none; }
  .hero { padding: 52px 0 64px; }
  .hero h1 { font-size: 31px; }
  .hero-sub { font-size: 16px; }
  .grid-3, .grid-2, .steps { grid-template-columns: 1fr; }
  .cta-band { padding: 44px 30px; }
  .cta-band h2 { font-size: 25px; }
  .page-hero h1 { font-size: 30px; }
  .review-card { padding: 30px 24px; }
  .review-text { font-size: 16.5px; }
  .modal-box { margin: 4vh 16px 0; padding: 32px 22px 26px; }
  .qr-grid, .modal-actions { grid-template-columns: 1fr; }
  .qr-card img { width: 170px; }
  .spec-table th { width: 130px; }
  .dl-spec { grid-template-columns: 1fr; }
  .footer-main { grid-template-columns: 1fr; gap: 32px; padding: 48px 0 36px; }
  .stat .num { font-size: 34px; }
}

/* 无障碍与动效偏好 */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; scroll-behavior: auto !important; }
}
:focus-visible { outline: 3px solid rgba(74,145,226,.5); outline-offset: 2px; }