/* =========================================================
   Mp3tag 官方推广网站 - 全局样式表
   设计语言：扁平现代专业
   配色：基于 Logo（#990000 主红 / #ffc800 金色 / #23233e 深色文本）
   ========================================================= */

/* ---------- 设计变量 ---------- */
:root {
  --c-primary: #990000;
  --c-primary-dark: #6b0000;
  --c-primary-light: #c9302c;
  --c-accent: #ffc800;
  --c-accent-dark: #d9a900;
  --c-text: #23233e;
  --c-text-soft: #5a5a73;
  --c-text-mute: #8a8a9a;
  --c-bg: #ffffff;
  --c-bg-soft: #f8f9fb;
  --c-bg-tint: #f3f4f8;
  --c-border: #e6e7ee;
  --c-border-soft: #efeff5;
  --c-success: #2e9e5b;
  --c-info: #2a6fb5;

  --radius-sm: 6px;
  --radius: 10px;
  --radius-lg: 16px;
  --radius-xl: 22px;

  --shadow-sm: 0 1px 3px rgba(35,35,62,.06), 0 1px 2px rgba(35,35,62,.04);
  --shadow: 0 4px 16px rgba(35,35,62,.08), 0 1px 4px rgba(35,35,62,.05);
  --shadow-lg: 0 18px 50px rgba(35,35,62,.12), 0 6px 18px rgba(35,35,62,.07);
  --shadow-primary: 0 10px 30px rgba(153,0,0,.22);

  --container: 1200px;
  --header-h: 70px;

  --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB",
    "Noto Sans SC", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-mono: "SFMono-Regular", "JetBrains Mono", Consolas, Menlo, monospace;

  --ease: cubic-bezier(.4, 0, .2, 1);
}

/* ---------- 基础重置 ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
img, svg { max-width: 100%; display: block; }
a { color: var(--c-primary); text-decoration: none; transition: color .2s var(--ease); }
a:hover { color: var(--c-primary-dark); }
ul, ol { padding-left: 1.2em; }
h1, h2, h3, h4, h5 {
  margin: 0 0 .6em;
  font-weight: 700;
  line-height: 1.25;
  color: var(--c-text);
  letter-spacing: -.01em;
}
h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.4rem; }
h4 { font-size: 1.15rem; }
p { margin: 0 0 1em; }

/* ---------- 容器与栅格 ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}
.section { padding: 80px 0; }
.section-sm { padding: 56px 0; }
.section-soft { background: var(--c-bg-soft); }
.section-tint { background: var(--c-bg-tint); }
.section-primary {
  background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-dark) 100%);
  color: #fff;
}
.section-primary h1,
.section-primary h2,
.section-primary h3 { color: #fff; }

.grid { display: grid; gap: 24px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* ---------- 通用组件 ---------- */
.eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--c-primary);
  background: rgba(153,0,0,.08);
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 18px;
}
.eyebrow.on-dark {
  color: var(--c-accent);
  background: rgba(255,200,0,.15);
}

.section-title {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 50px;
}
.section-title h2 { margin-bottom: 14px; }
.section-title p {
  color: var(--c-text-soft);
  font-size: 1.05rem;
  margin: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 28px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 15px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: all .22s var(--ease);
  text-decoration: none;
  white-space: nowrap;
  line-height: 1.2;
}
.btn-primary {
  background: var(--c-primary);
  color: #fff;
  box-shadow: var(--shadow-primary);
}
.btn-primary:hover {
  background: var(--c-primary-dark);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 14px 36px rgba(153,0,0,.3);
}
.btn-accent {
  background: var(--c-accent);
  color: var(--c-text);
}
.btn-accent:hover {
  background: var(--c-accent-dark);
  color: var(--c-text);
  transform: translateY(-2px);
}
.btn-ghost {
  background: transparent;
  color: var(--c-primary);
  border-color: var(--c-border);
}
.btn-ghost:hover {
  background: var(--c-bg-soft);
  border-color: var(--c-primary);
  color: var(--c-primary);
}
.btn-light {
  background: rgba(255,255,255,.14);
  color: #fff;
  border-color: rgba(255,255,255,.32);
  backdrop-filter: blur(6px);
}
.btn-light:hover {
  background: rgba(255,255,255,.24);
  color: #fff;
}
.btn-lg { padding: 16px 36px; font-size: 16px; }
.btn-block { display: flex; width: 100%; }

/* ---------- 头部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--c-border-soft);
  height: var(--header-h);
}
.site-header .container {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--c-text);
  font-weight: 800;
  font-size: 19px;
  letter-spacing: -.01em;
}
.brand:hover { color: var(--c-text); }
.brand img { width: 38px; height: 38px; }
.brand .brand-name { display: flex; align-items: baseline; gap: 4px; }
.brand .brand-name b { color: var(--c-primary); }
.brand .brand-tag {
  font-size: 11px;
  font-weight: 600;
  color: var(--c-text-mute);
  letter-spacing: .04em;
  padding-top: 2px;
}

.main-nav { display: flex; align-items: center; gap: 4px; }
.main-nav a {
  color: var(--c-text-soft);
  font-weight: 500;
  font-size: 15px;
  padding: 9px 16px;
  border-radius: var(--radius-sm);
  transition: all .2s var(--ease);
}
.main-nav a:hover { color: var(--c-primary); background: rgba(153,0,0,.06); }
.main-nav a.active { color: var(--c-primary); background: rgba(153,0,0,.08); }

.header-cta { display: flex; align-items: center; gap: 12px; }
.header-cta .btn { padding: 10px 22px; font-size: 14px; }

/* 移动端汉堡 */
.nav-toggle {
  display: none;
  background: none;
  border: 0;
  padding: 8px;
  cursor: pointer;
}
.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--c-text);
  margin: 5px 0;
  transition: .3s var(--ease);
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  padding: 90px 0 80px;
  background:
    radial-gradient(1000px 500px at 80% -10%, rgba(255,200,0,.18), transparent 60%),
    radial-gradient(800px 600px at 0% 100%, rgba(153,0,0,.08), transparent 55%),
    var(--c-bg-soft);
  overflow: hidden;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  gap: 56px;
  align-items: center;
}
.hero h1 {
  font-size: 3.1rem;
  margin-bottom: 22px;
  letter-spacing: -.02em;
}
.hero h1 .accent { color: var(--c-primary); }
.hero .lead {
  font-size: 1.18rem;
  color: var(--c-text-soft);
  margin-bottom: 32px;
  max-width: 560px;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 26px; }
.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 22px 32px;
  font-size: 14px;
  color: var(--c-text-soft);
}
.hero-meta b { color: var(--c-text); font-size: 22px; display: block; font-weight: 800; }
.hero-meta span { font-size: 13px; }

.hero-visual {
  position: relative;
}
.hero-card {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: 18px;
  position: relative;
  z-index: 2;
}
.hero-card .card-bar {
  display: flex; align-items: center; gap: 7px;
  padding-bottom: 12px; border-bottom: 1px solid var(--c-border-soft);
  margin-bottom: 14px;
}
.hero-card .dot { width: 11px; height: 11px; border-radius: 50%; }
.hero-card .dot.r { background: #ff5f56; }
.hero-card .dot.y { background: #ffbd2e; }
.hero-card .dot.g { background: #27c93f; }
.hero-card .card-title { margin-left: 8px; font-size: 13px; color: var(--c-text-mute); font-weight: 500; }

.hero-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}
.hero-table th, .hero-table td {
  text-align: left;
  padding: 9px 10px;
  border-bottom: 1px solid var(--c-border-soft);
}
.hero-table th {
  background: var(--c-bg-tint);
  color: var(--c-text-soft);
  font-weight: 600;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: .05em;
}
.hero-table td.tag {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-primary);
}
.hero-table tr:last-child td { border-bottom: 0; }

.hero-bubble {
  position: absolute;
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  padding: 12px 16px;
  box-shadow: var(--shadow);
  font-size: 13px;
  display: flex; align-items: center; gap: 10px;
  font-weight: 600;
}
.hero-bubble .ico { width: 32px; height: 32px; border-radius: 8px; display: flex; align-items: center; justify-content: center; }
.hero-bubble.b1 { top: -18px; right: 12px; }
.hero-bubble.b1 .ico { background: rgba(153,0,0,.1); color: var(--c-primary); }
.hero-bubble.b2 { bottom: -22px; left: -22px; }
.hero-bubble.b2 .ico { background: rgba(255,200,0,.18); color: var(--c-accent-dark); }

/* ---------- 信任栏 ---------- */
.trust-bar {
  background: var(--c-text);
  color: #c8c8d8;
  padding: 22px 0;
  font-size: 14px;
}
.trust-bar .container {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 16px;
}
.trust-bar .trust-items { display: flex; flex-wrap: wrap; gap: 28px; }
.trust-bar .trust-item { display: flex; align-items: center; gap: 8px; }
.trust-bar .trust-item svg { color: var(--c-accent); flex-shrink: 0; }
.trust-bar .trust-item b { color: #fff; }

/* ---------- 特性卡片 ---------- */
.feature-card {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 30px;
  transition: all .25s var(--ease);
  height: 100%;
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(153,0,0,.2);
}
.feature-card .fc-icon {
  width: 54px; height: 54px;
  border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 18px;
  background: rgba(153,0,0,.08);
  color: var(--c-primary);
}
.feature-card .fc-icon.accent {
  background: rgba(255,200,0,.18);
  color: var(--c-accent-dark);
}
.feature-card h3 { font-size: 1.2rem; margin-bottom: 10px; }
.feature-card p { color: var(--c-text-soft); margin: 0; font-size: .96rem; }

/* ---------- 使用场景 ---------- */
.scenario-card {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  gap: 18px;
  align-items: flex-start;
  transition: all .25s var(--ease);
  height: 100%;
}
.scenario-card:hover {
  border-color: var(--c-primary);
  box-shadow: var(--shadow);
  transform: translateX(2px);
}
.scenario-card .sc-num {
  flex-shrink: 0;
  width: 44px; height: 44px;
  border-radius: var(--radius);
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-dark));
  color: #fff;
  font-weight: 800;
  font-size: 18px;
  display: flex; align-items: center; justify-content: center;
}
.scenario-card h3 { font-size: 1.1rem; margin-bottom: 6px; }
.scenario-card p { color: var(--c-text-soft); margin: 0; font-size: .94rem; }

/* ---------- 用户评价 ---------- */
.review-card {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  height: 100%;
  position: relative;
}
.review-card::before {
  content: "\201C";
  position: absolute;
  top: 14px; right: 24px;
  font-size: 72px;
  font-family: Georgia, serif;
  color: rgba(153,0,0,.1);
  line-height: 1;
}
.review-stars { color: var(--c-accent); font-size: 16px; letter-spacing: 2px; }
.review-text {
  color: var(--c-text);
  font-size: .98rem;
  line-height: 1.65;
  margin: 0;
  flex: 1;
}
.review-author { display: flex; align-items: center; gap: 12px; padding-top: 4px; border-top: 1px solid var(--c-border-soft); }
.review-avatar {
  width: 42px; height: 42px; border-radius: 50%;
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-light));
  color: #fff;
  font-weight: 700;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px;
}
.review-meta b { display: block; font-size: 14px; color: var(--c-text); }
.review-meta span { font-size: 12px; color: var(--c-text-mute); }

/* ---------- CTA 区 ---------- */
.cta-band {
  background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-dark) 100%);
  color: #fff;
  border-radius: var(--radius-xl);
  padding: 56px 48px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.cta-band::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(500px 200px at 20% 0%, rgba(255,200,0,.25), transparent 60%),
    radial-gradient(500px 250px at 90% 100%, rgba(255,200,0,.18), transparent 60%);
  pointer-events: none;
}
.cta-band > * { position: relative; z-index: 1; }
.cta-band h2 { color: #fff; font-size: 2.2rem; margin-bottom: 14px; }
.cta-band p { color: rgba(255,255,255,.86); font-size: 1.08rem; max-width: 620px; margin: 0 auto 28px; }
.cta-band .hero-actions { justify-content: center; }

/* ---------- 页脚 ---------- */
.site-footer {
  background: #1a1a2e;
  color: #b8b8c8;
  padding: 60px 0 24px;
  font-size: 14px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 36px;
  border-bottom: 1px solid rgba(255,255,255,.08);
}
.footer-brand .brand { color: #fff; margin-bottom: 14px; }
.footer-brand p { color: #9999ad; line-height: 1.7; font-size: 13.5px; }
.footer-col h4 {
  color: #fff;
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: .08em;
  margin-bottom: 16px;
}
.footer-col ul { list-style: none; padding: 0; margin: 0; }
.footer-col li { margin-bottom: 10px; }
.footer-col a { color: #b8b8c8; font-size: 13.5px; }
.footer-col a:hover { color: var(--c-accent); }
.footer-bottom {
  padding-top: 22px;
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px;
  font-size: 12.5px;
  color: #8888a0;
}
.footer-bottom a { color: #8888a0; }
.footer-bottom a:hover { color: var(--c-accent); }

/* ---------- 通用页头（内页 hero） ---------- */
.page-hero {
  background:
    radial-gradient(800px 400px at 90% 0%, rgba(255,200,0,.15), transparent 55%),
    radial-gradient(700px 500px at -10% 100%, rgba(153,0,0,.08), transparent 55%),
    var(--c-bg-soft);
  padding: 70px 0 60px;
  border-bottom: 1px solid var(--c-border-soft);
}
.page-hero h1 { font-size: 2.6rem; margin-bottom: 14px; }
.page-hero p { color: var(--c-text-soft); font-size: 1.1rem; max-width: 720px; margin: 0; }
.breadcrumb { font-size: 13px; color: var(--c-text-mute); margin-bottom: 18px; }
.breadcrumb a { color: var(--c-text-mute); }
.breadcrumb a:hover { color: var(--c-primary); }
.breadcrumb span { margin: 0 8px; color: var(--c-border); }

/* ---------- 下载页样式 ---------- */
.download-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.dl-card {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 30px;
  text-align: center;
  transition: all .25s var(--ease);
  display: flex; flex-direction: column;
}
.dl-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(153,0,0,.25);
}
.dl-card.featured {
  border-color: var(--c-primary);
  border-width: 2px;
  position: relative;
}
.dl-card.featured::after {
  content: "推荐";
  position: absolute;
  top: -12px; left: 50%;
  transform: translateX(-50%);
  background: var(--c-accent);
  color: var(--c-text);
  font-size: 12px;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 999px;
  letter-spacing: .04em;
}
.dl-card .dl-icon {
  width: 64px; height: 64px;
  margin: 0 auto 18px;
  border-radius: var(--radius);
  background: rgba(153,0,0,.08);
  color: var(--c-primary);
  display: flex; align-items: center; justify-content: center;
}
.dl-card h3 { font-size: 1.25rem; margin-bottom: 6px; }
.dl-card .dl-version { color: var(--c-text-mute); font-size: 13px; margin-bottom: 16px; }
.dl-card .dl-desc {
  text-align: left;
  color: var(--c-text-soft);
  font-size: 14px;
  flex: 1;
  margin-bottom: 22px;
}
.dl-card .dl-desc ul { list-style: none; padding: 0; margin: 0; }
.dl-card .dl-desc li { padding: 4px 0 4px 22px; position: relative; }
.dl-card .dl-desc li::before {
  content: "";
  position: absolute;
  left: 0; top: 11px;
  width: 14px; height: 8px;
  border-left: 2px solid var(--c-primary);
  border-bottom: 2px solid var(--c-primary);
  transform: rotate(-45deg);
}

/* 系统要求表 */
.spec-table {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--c-border);
}
.spec-table th, .spec-table td {
  padding: 16px 22px;
  text-align: left;
  border-bottom: 1px solid var(--c-border-soft);
}
.spec-table th {
  background: var(--c-bg-tint);
  font-weight: 700;
  width: 220px;
  color: var(--c-text);
}
.spec-table tr:last-child td { border-bottom: 0; }
.spec-table td { color: var(--c-text-soft); }

/* 版本历史 */
.changelog {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 8px 32px;
}
.changelog-item {
  padding: 22px 0;
  border-bottom: 1px solid var(--c-border-soft);
}
.changelog-item:last-child { border-bottom: 0; }
.changelog-item .cl-head { display: flex; align-items: center; gap: 12px; margin-bottom: 10px; flex-wrap: wrap; }
.changelog-item .cl-ver {
  background: var(--c-primary);
  color: #fff;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: var(--radius-sm);
  font-size: 13px;
}
.changelog-item .cl-date { color: var(--c-text-mute); font-size: 13px; }
.changelog-item ul { margin: 6px 0 0; color: var(--c-text-soft); font-size: 14px; }
.changelog-item li { padding: 3px 0; }

/* ---------- 功能页样式 ---------- */
.feature-detail {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 50px;
  align-items: center;
  padding: 50px 0;
  border-bottom: 1px solid var(--c-border-soft);
}
.feature-detail:last-child { border-bottom: 0; }
.feature-detail.flip > div:first-child { order: 2; }
.feature-detail .fd-visual {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow);
}
.feature-detail h3 { font-size: 1.65rem; margin-bottom: 14px; }
.feature-detail p { color: var(--c-text-soft); margin-bottom: 14px; }
.feature-detail .fd-list { list-style: none; padding: 0; margin: 16px 0 0; }
.feature-detail .fd-list li {
  padding: 7px 0 7px 28px;
  position: relative;
  color: var(--c-text);
  font-size: 15px;
}
.feature-detail .fd-list li::before {
  content: "";
  position: absolute;
  left: 0; top: 12px;
  width: 16px; height: 8px;
  border-left: 2.5px solid var(--c-primary);
  border-bottom: 2.5px solid var(--c-primary);
  transform: rotate(-45deg);
}

/* 格式标签云 */
.format-cloud {
  display: flex; flex-wrap: wrap; gap: 10px;
}
.format-tag {
  background: #fff;
  border: 1px solid var(--c-border);
  color: var(--c-text-soft);
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  transition: all .2s var(--ease);
}
.format-tag:hover {
  border-color: var(--c-primary);
  color: var(--c-primary);
  transform: translateY(-2px);
}
.format-tag.audio { border-left: 3px solid var(--c-primary); }
.format-tag.tag { border-left: 3px solid var(--c-accent); }

/* ---------- 关于页 ---------- */
.about-hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 50px;
  align-items: center;
}
.timeline {
  position: relative;
  padding-left: 32px;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 8px; top: 6px; bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--c-primary), var(--c-accent));
}
.timeline-item {
  position: relative;
  padding-bottom: 32px;
}
.timeline-item:last-child { padding-bottom: 0; }
.timeline-item::before {
  content: "";
  position: absolute;
  left: -28px; top: 6px;
  width: 14px; height: 14px;
  border-radius: 50%;
  background: #fff;
  border: 3px solid var(--c-primary);
}
.timeline-item .tl-year {
  font-size: 14px;
  font-weight: 800;
  color: var(--c-primary);
  margin-bottom: 4px;
}
.timeline-item h4 { margin-bottom: 6px; font-size: 1.05rem; }
.timeline-item p { color: var(--c-text-soft); margin: 0; font-size: 14px; }

.dev-card {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  display: flex; gap: 22px; align-items: center;
}
.dev-card .dev-avatar {
  width: 88px; height: 88px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-dark));
  color: #fff;
  font-size: 30px;
  font-weight: 800;
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
}
.dev-card .dev-info h3 { margin-bottom: 4px; }
.dev-card .dev-info .dev-loc { color: var(--c-text-mute); font-size: 13px; margin-bottom: 10px; }
.dev-card .dev-info p { margin: 0; color: var(--c-text-soft); font-size: 14px; }

/* ---------- FAQ ---------- */
.faq-item {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
}
.faq-q {
  width: 100%;
  background: none;
  border: 0;
  padding: 18px 22px;
  text-align: left;
  font-size: 15px;
  font-weight: 600;
  color: var(--c-text);
  cursor: pointer;
  display: flex; justify-content: space-between; align-items: center;
  font-family: inherit;
}
.faq-q .ico { color: var(--c-primary); font-size: 22px; transition: transform .25s var(--ease); }
.faq-item.open .faq-q .ico { transform: rotate(45deg); }
.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height .3s var(--ease);
  color: var(--c-text-soft);
  font-size: 14.5px;
}
.faq-item.open .faq-a { max-height: 400px; }
.faq-a-inner { padding: 0 22px 20px; }

/* ---------- 下载弹窗 ---------- */
.modal-mask {
  position: fixed; inset: 0;
  background: rgba(20,20,35,.55);
  backdrop-filter: blur(4px);
  display: flex; align-items: center; justify-content: center;
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transition: opacity .25s var(--ease), visibility .25s var(--ease);
  padding: 20px;
}
.modal-mask.open { opacity: 1; visibility: visible; }
.modal-box {
  background: #fff;
  border-radius: var(--radius-xl);
  width: 100%;
  max-width: 720px;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: 0 30px 80px rgba(0,0,0,.3);
  transform: translateY(20px) scale(.97);
  transition: transform .3s var(--ease);
}
.modal-mask.open .modal-box { transform: translateY(0) scale(1); }
.modal-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 22px 28px;
  border-bottom: 1px solid var(--c-border-soft);
  background: #333;
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
  color: #fff;
}
.modal-head h3 { margin: 0; color: #fff; font-size: 1.3rem; }
.modal-head p { margin: 4px 0 0; color: rgba(255,255,255,.8); font-size: 13px; }
.modal-close {
  background: rgba(255,255,255,.18);
  border: 0;
  color: #fff;
  width: 34px; height: 34px;
  border-radius: 50%;
  font-size: 20px;
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: background .2s var(--ease);
}
.modal-close:hover { background: rgba(255,255,255,.32); }
.modal-body { padding: 28px; }

.qr-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 22px;
}
.qr-item {
  text-align: center;
  padding: 22px 16px;
  border: 1.5px solid var(--c-border);
  border-radius: var(--radius-lg);
  transition: all .25s var(--ease);
  background: var(--c-bg-soft);
}
.qr-item:hover {
  border-color: var(--c-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
  background: #fff;
}
.qr-item img {
  width: 180px; height: 180px;
  margin: 0 auto 14px;
  border-radius: var(--radius);
  background: #fff;
  padding: 8px;
}
.qr-item h4 { margin: 0 0 4px; font-size: 1.05rem; }
.qr-item p { margin: 0; font-size: 12.5px; color: var(--c-text-mute); }

.modal-notice {
  background: rgba(255,200,0,.12);
  border-left: 3px solid var(--c-accent);
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: var(--c-text-soft);
  margin-bottom: 18px;
}
.modal-notice b { color: var(--c-text); }

.modal-actions {
  display: flex; gap: 12px; flex-wrap: wrap; justify-content: center;
}

/* ---------- 通用工具类 ---------- */
.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mb-0 { margin-bottom: 0; }
.text-soft { color: var(--c-text-soft); }
.text-mute { color: var(--c-text-mute); }
.lead { font-size: 1.1rem; color: var(--c-text-soft); }

/* ---------- 滚动出现动画 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity .6s var(--ease), transform .6s var(--ease);
}
.reveal.in { opacity: 1; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 992px) {
  h1 { font-size: 2.1rem; }
  h2 { font-size: 1.7rem; }
  .hero h1 { font-size: 2.4rem; }
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 30px; }
  .feature-detail { grid-template-columns: 1fr; gap: 30px; }
  .feature-detail.flip > div:first-child { order: 0; }
  .about-hero-grid { grid-template-columns: 1fr; }
  .download-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .section { padding: 56px 0; }
  .container { padding: 0 18px; }
  h1 { font-size: 1.85rem; }
  h2 { font-size: 1.5rem; }
  .hero { padding: 60px 0 50px; }
  .hero h1 { font-size: 2rem; }
  .hero .lead { font-size: 1.02rem; }
  .hero-actions .btn { flex: 1; min-width: 0; }
  .hero-bubble { display: none; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }

  /* 移动端导航 */
  .nav-toggle { display: block; }
  .main-nav {
    position: fixed;
    top: var(--header-h);
    left: 0; right: 0;
    background: #fff;
    flex-direction: column;
    align-items: stretch;
    padding: 12px 18px;
    border-bottom: 1px solid var(--c-border);
    box-shadow: var(--shadow);
    transform: translateY(-120%);
    transition: transform .3s var(--ease);
    gap: 0;
  }
  .main-nav.open { transform: translateY(0); }
  .main-nav a { padding: 13px 14px; border-radius: var(--radius-sm); }
  .header-cta .btn-ghost { display: none; }

  .cta-band { padding: 40px 24px; }
  .cta-band h2 { font-size: 1.7rem; }
  .footer-grid { grid-template-columns: 1fr; gap: 26px; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .qr-grid { grid-template-columns: 1fr; }
  .qr-item img { width: 160px; height: 160px; }
  .modal-head { padding: 18px 20px; }
  .modal-body { padding: 20px; }
  .review-card::before { font-size: 56px; }
  .dev-card { flex-direction: column; text-align: center; }
  .page-hero { padding: 50px 0 40px; }
  .page-hero h1 { font-size: 2rem; }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 1.7rem; }
  .section-title { margin-bottom: 32px; }
  .trust-bar .trust-items { gap: 16px; }
  .feature-card, .scenario-card, .review-card { padding: 22px; }
  .brand .brand-tag { display: none; }
}