/* ===== 基础 ===== */
:root {
  --bg: #ffffff;
  --bg-alt: #f5f7fb;
  --text: #1a1f2b;
  --text-soft: #5b6478;
  --primary: #4f8cff;
  --primary-dark: #2f6fe0;
  --primary-soft: #eaf1ff;
  --border: #e6eaf2;
  --radius: 16px;
  --shadow: 0 10px 30px rgba(31, 45, 80, 0.08);
  --shadow-hover: 0 18px 44px rgba(31, 45, 80, 0.16);
  --maxw: 1140px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { text-decoration: none; color: inherit; }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

/* ===== 按钮 ===== */
.btn {
  display: inline-block;
  padding: 11px 22px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 15px;
  cursor: pointer;
  transition: all .2s ease;
  border: 1px solid transparent;
  white-space: nowrap;
}
.btn-lg { padding: 14px 30px; font-size: 16px; }
.btn-block { display: block; text-align: center; width: 100%; }
.btn-primary { background: var(--primary); color: #fff; box-shadow: 0 8px 20px rgba(79,140,255,.35); }
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-2px); }
.btn-outline { background: #fff; color: var(--primary); border-color: var(--primary); }
.btn-outline:hover { background: var(--primary-soft); }
.btn-ghost { background: rgba(255,255,255,.15); color: #fff; border-color: rgba(255,255,255,.5); }
.btn-ghost:hover { background: rgba(255,255,255,.28); }
.btn-nav { background: var(--primary); color: #fff; padding: 9px 18px; }
.btn-nav:hover { background: var(--primary-dark); }

/* ===== 导航 ===== */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.85);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { font-weight: 800; font-size: 19px; display: flex; align-items: center; gap: 8px; }
.logo-mark {
  display: inline-flex; align-items: center; justify-content: center;
  width: 30px; height: 30px; border-radius: 9px;
  background: linear-gradient(135deg, var(--primary), #7aa6ff);
  color: #fff; font-size: 16px;
}
.nav-links { display: flex; gap: 28px; font-weight: 500; color: var(--text-soft); }
.nav-links a { position: relative; transition: color .2s; }
.nav-links a:hover, .nav-links a.active { color: var(--primary); }
.nav-toggle { display: none; background: none; border: none; font-size: 24px; cursor: pointer; color: var(--text); }

/* ===== Hero ===== */
.hero {
  background: radial-gradient(1200px 500px at 80% -10%, #e8f0ff 0%, transparent 60%),
              linear-gradient(160deg, #0e1426 0%, #16203a 100%);
  color: #fff; padding: 70px 0 90px; overflow: hidden;
}
.hero-inner { display: grid; grid-template-columns: 1.1fr .9fr; gap: 40px; align-items: center; }
.badge {
  display: inline-block; background: rgba(255,255,255,.12); border: 1px solid rgba(255,255,255,.25);
  padding: 6px 14px; border-radius: 999px; font-size: 13px; margin-bottom: 18px;
}
.hero h1 { font-size: 46px; line-height: 1.2; font-weight: 800; letter-spacing: -1px; }
.hero-sub { margin: 18px 0 28px; font-size: 17px; color: #c8d3ea; max-width: 540px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-meta { display: flex; gap: 22px; margin-top: 26px; color: #aeb9d4; font-size: 14px; flex-wrap: wrap; }
.hero-art { display: flex; justify-content: center; }
.player-mock { width: 100%; max-width: 440px; filter: drop-shadow(0 20px 50px rgba(0,0,0,.45)); }

/* ===== 通用 section ===== */
.section { padding: 80px 0; }
.section-alt { background: var(--bg-alt); }
.section-head { text-align: center; max-width: 680px; margin: 0 auto 50px; }
.eyebrow {
  display: inline-block; color: var(--primary); font-weight: 700; font-size: 14px;
  letter-spacing: 1px; margin-bottom: 12px; text-transform: uppercase;
}
.section-head h2 { font-size: 34px; font-weight: 800; letter-spacing: -.5px; }
.section-head p { margin-top: 12px; color: var(--text-soft); font-size: 16px; }

/* ===== 功能卡片 ===== */
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.feature-card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 30px 26px; box-shadow: var(--shadow); transition: all .25s ease;
}
.feature-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-hover); border-color: #cfddff; }
.feature-icon {
  width: 56px; height: 56px; border-radius: 14px; background: var(--primary-soft);
  display: flex; align-items: center; justify-content: center; font-size: 28px; margin-bottom: 18px;
}
.feature-card h3 { font-size: 19px; margin-bottom: 10px; }
.feature-card p { color: var(--text-soft); font-size: 15px; }

/* ===== 截图 ===== */
.shots-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.shot {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; box-shadow: var(--shadow); transition: all .25s ease;
}
.shot:hover { transform: translateY(-6px); box-shadow: var(--shadow-hover); }
.shot svg { display: block; width: 100%; height: auto; }
.shot figcaption { padding: 16px; font-weight: 600; font-size: 15px; text-align: center; }

/* ===== 下载 ===== */
.download-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; max-width: 760px; margin: 0 auto; }
.dl-card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 34px 30px; box-shadow: var(--shadow); text-align: center; position: relative;
  transition: all .25s ease;
}
.dl-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-hover); }
.dl-featured { border-color: var(--primary); box-shadow: 0 14px 40px rgba(79,140,255,.22); }
.dl-tag {
  position: absolute; top: -14px; left: 50%; transform: translateX(-50%);
  background: linear-gradient(135deg, var(--primary), #7aa6ff); color: #fff;
  padding: 5px 16px; border-radius: 999px; font-size: 13px; font-weight: 700; white-space: nowrap;
}
.dl-card h3 { font-size: 24px; margin-bottom: 6px; }
.dl-desc { color: var(--text-soft); font-size: 14px; margin-bottom: 20px; }
.dl-spec { list-style: none; display: flex; justify-content: center; gap: 18px; margin-bottom: 26px; flex-wrap: wrap; color: var(--text-soft); font-size: 14px; }
.dl-note { text-align: center; margin-top: 26px; color: var(--text-soft); font-size: 14px; }

/* ===== FAQ ===== */
.faq { max-width: 820px; margin: 0 auto; display: flex; flex-direction: column; gap: 12px; }
.faq-item { background: #fff; border: 1px solid var(--border); border-radius: 12px; overflow: hidden; }
.faq-q {
  width: 100%; text-align: left; background: none; border: none; cursor: pointer;
  padding: 18px 22px; font-size: 16px; font-weight: 600; color: var(--text);
  display: flex; justify-content: space-between; align-items: center; gap: 12px;
}
.faq-plus { color: var(--primary); font-size: 22px; font-weight: 400; transition: transform .2s; }
.faq-item.open .faq-plus { transform: rotate(45deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .3s ease; }
.faq-a p { padding: 0 22px 18px; color: var(--text-soft); font-size: 15px; }
.faq-a code { background: var(--bg-alt); padding: 2px 7px; border-radius: 6px; font-size: 13px; color: var(--primary-dark); }

/* ===== 页脚 ===== */
.footer { background: #0e1426; color: #c8d3ea; padding: 56px 0 0; }
.footer-inner { display: grid; grid-template-columns: 1.4fr 1fr; gap: 30px; padding-bottom: 36px; }
.footer .logo { color: #fff; }
.footer-brand p { margin-top: 14px; color: #8d9ab8; font-size: 14px; max-width: 380px; }
.footer-links { display: flex; flex-direction: column; gap: 12px; font-size: 15px; }
.footer-links a:hover { color: #fff; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.08); padding: 20px 0; }
.footer-bottom p { text-align: center; color: #727f9c; font-size: 13px; }

/* ===== 返回顶部 ===== */
.to-top {
  position: fixed; right: 24px; bottom: 24px; width: 46px; height: 46px; border-radius: 50%;
  background: var(--primary); color: #fff; border: none; font-size: 22px; cursor: pointer;
  box-shadow: 0 10px 24px rgba(79,140,255,.4); opacity: 0; visibility: hidden;
  transition: all .25s ease; z-index: 90;
}
.to-top.show { opacity: 1; visibility: visible; }
.to-top:hover { background: var(--primary-dark); transform: translateY(-3px); }

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero-art { order: -1; }
  .hero h1 { font-size: 38px; }
  .features-grid, .shots-grid { grid-template-columns: repeat(2, 1fr); }
  .nav-links { display: none; }
  .nav-toggle { display: block; }
  .nav-links.open {
    display: flex; flex-direction: column; gap: 14px;
    position: absolute; top: 64px; left: 0; right: 0; background: #fff;
    padding: 18px 20px; border-bottom: 1px solid var(--border); box-shadow: var(--shadow);
  }
}

@media (max-width: 600px) {
  .section { padding: 56px 0; }
  .section-head h2 { font-size: 27px; }
  .hero h1 { font-size: 32px; }
  .features-grid, .shots-grid, .download-grid { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; }
  .hero-meta { gap: 14px; }
}