/* ===== 基础与变量 ===== */
:root {
  --primary: #FF7A45;
  --primary-dark: #F05E22;
  --dark: #23282F;
  --text: #2E3440;
  --text-sub: #66707D;
  --border: #F1E7DC;
  --bg: #FBF6F0;
  --card: #FFFFFF;
  --ok: #2E9E5B;
  --bad: #E05B5B;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 6px 20px rgba(255, 122, 69, .10);
  --shadow-hover: 0 14px 30px rgba(255, 122, 69, .18);
  --nav-h: 64px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
[id] { scroll-margin-top: calc(var(--nav-h) + 14px); }
button { font-family: inherit; }

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ===== 通用组件 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  border-radius: 12px;
  cursor: pointer;
  border: none;
  white-space: nowrap;
  transition: transform .25s ease, box-shadow .25s ease, background .25s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-dark { background: var(--dark); color: #fff; }
.btn-dark:hover { background: #333B47; }
.btn-lg { padding: 14px 30px; font-size: 16px; }

.section { padding: 76px 0; }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 44px; }
.eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 2px;
  color: var(--primary);
  margin-bottom: 10px;
}
.section-title { font-size: 30px; font-weight: 800; color: var(--dark); line-height: 1.3; }
.section-sub { margin-top: 12px; color: var(--text-sub); font-size: 15px; }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: transform .3s ease, box-shadow .3s ease;
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-hover); }

/* ===== 顶部导航 ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-h);
  background: #fff;
  border-bottom: 1px solid var(--border);
  transition: box-shadow .3s ease;
}
.header.scrolled { box-shadow: 0 4px 18px rgba(35, 40, 47, .06); }
.header-inner { display: flex; align-items: center; gap: 24px; height: 100%; }
.logo {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 21px;
  font-weight: 800;
  color: var(--dark);
  white-space: nowrap;
}
.nav { display: flex; align-items: center; gap: 2px; flex: 1; justify-content: center; }
.nav a {
  padding: 6px 10px;
  font-size: 14px;
  color: var(--text-sub);
  border-radius: 8px;
  white-space: nowrap;
  transition: color .2s ease, background .2s ease;
}
.nav a:hover { color: var(--primary); background: rgba(255, 122, 69, .08); }
.nav a.active { color: var(--primary); font-weight: 600; }
.header .nav-download { padding: 5px 14px; font-size: 13px; border-radius: 999px; }

/* ===== Hero 首屏 ===== */
.hero { padding: calc(var(--nav-h) + 44px) 0 72px; }
.hero-inner { display: grid; grid-template-columns: 1.05fr .95fr; gap: 52px; align-items: center; }
.hero-copy .eyebrow { margin-bottom: 14px; }
.hero h1 { font-size: 42px; font-weight: 800; line-height: 1.25; color: var(--dark); }
.hero .ver { color: var(--primary); }
.hero-desc { margin: 18px 0 30px; font-size: 16px; color: var(--text-sub); max-width: 520px; }
.hero-btns { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-img {
  border-radius: 20px;
  overflow: hidden;
  box-shadow: var(--shadow-hover);
}
.hero-img img { width: 100%; height: auto; }

/* ===== 作品预览 ===== */
.works-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.work-card { overflow: hidden; }
.work-card img { width: 100%; height: 100%; aspect-ratio: 3 / 4; object-fit: cover; }

/* ===== 产品介绍 ===== */
.intro-card { max-width: 860px; margin: 0 auto; padding: 44px 48px; }
.intro-card p { color: var(--text-sub); font-size: 15.5px; margin-bottom: 16px; }
.intro-card p:last-of-type { margin-bottom: 0; }
.intro-points { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 28px; }
.intro-point {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 16px 18px;
  text-align: center;
}
.intro-point strong { display: block; color: var(--dark); font-size: 15px; margin-bottom: 4px; }
.intro-point span { font-size: 13px; color: var(--text-sub); }

/* ===== 核心功能 ===== */
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.feature-card { padding: 30px 26px; }
.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  background: rgba(255, 122, 69, .12);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
}
.feature-icon svg { width: 26px; height: 26px; }
.feature-card h3 { font-size: 18px; color: var(--dark); margin-bottom: 8px; }
.feature-card p { font-size: 14px; color: var(--text-sub); }

/* ===== 优势对比 ===== */
.compare-card { max-width: 960px; margin: 0 auto; overflow: hidden; }
.compare-row { display: grid; grid-template-columns: 1.2fr 1fr 1fr; align-items: center; }
.compare-row + .compare-row { border-top: 1px solid var(--border); }
.compare-row.head { background: var(--bg); font-weight: 700; color: var(--dark); }
.compare-cell { padding: 18px 22px; font-size: 14.5px; }
.compare-item { color: var(--dark); font-weight: 600; }
.compare-us { color: var(--dark); }
.compare-us .mark { color: var(--ok); font-weight: 800; }
.compare-other { color: var(--text-sub); }
.compare-other .mark { color: var(--bad); font-weight: 800; }

/* ===== 平台数据 ===== */
.data-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.data-card { padding: 34px 20px; text-align: center; }
.data-num { font-size: 38px; font-weight: 800; color: var(--primary); line-height: 1.2; }
.data-label { margin-top: 8px; font-size: 14px; color: var(--text-sub); }

/* ===== 用户评价 ===== */
.reviews-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.review-card { padding: 26px 26px 24px; }
.review-top { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; }
.review-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 700;
  flex-shrink: 0;
}
.review-card:nth-child(2) .review-avatar,
.review-card:nth-child(5) .review-avatar { background: #FF9F43; }
.review-card:nth-child(3) .review-avatar,
.review-card:nth-child(6) .review-avatar { background: #F05E22; }
.review-name { font-weight: 700; color: var(--dark); font-size: 15px; }
.review-stars { color: #FFB020; font-size: 14px; letter-spacing: 2px; margin-top: 2px; }
.review-text { font-size: 14px; color: var(--text-sub); line-height: 1.8; }

/* ===== 版本更新 ===== */
.version-card { max-width: 860px; margin: 0 auto; padding: 40px 44px; }
.version-head { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; margin-bottom: 22px; }
.version-badge {
  background: var(--primary);
  color: #fff;
  font-weight: 800;
  padding: 6px 16px;
  border-radius: 999px;
  font-size: 16px;
}
.version-date { color: var(--text-sub); font-size: 14px; }
.version-list li {
  position: relative;
  padding-left: 22px;
  color: var(--text-sub);
  font-size: 15px;
  margin-bottom: 12px;
}
.version-list li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 10px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--primary);
}

/* ===== FAQ ===== */
.faq-list { max-width: 860px; margin: 0 auto; }
.faq-item {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.faq-item + .faq-item { margin-top: 16px; }
.faq-item.open { box-shadow: var(--shadow); }
.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  width: 100%;
  background: none;
  border: none;
  cursor: pointer;
  padding: 20px 24px;
  font-size: 16px;
  font-weight: 600;
  color: var(--dark);
  text-align: left;
}
.faq-icon { position: relative; width: 20px; height: 20px; flex-shrink: 0; }
.faq-icon::before,
.faq-icon::after {
  content: "";
  position: absolute;
  background: var(--primary);
  border-radius: 2px;
  transition: transform .3s ease;
}
.faq-icon::before { left: 3px; right: 3px; top: 9px; height: 2px; }
.faq-icon::after { top: 3px; bottom: 3px; left: 9px; width: 2px; }
.faq-item.open .faq-icon::after { transform: scaleY(0); }
.faq-panel { display: grid; grid-template-rows: 0fr; transition: grid-template-rows .35s ease; }
.faq-item.open .faq-panel { grid-template-rows: 1fr; }
.faq-answer { overflow: hidden; min-height: 0; }
.faq-answer p { padding: 0 24px 22px; color: var(--text-sub); font-size: 14.5px; line-height: 1.8; }

/* ===== 下载区域 ===== */
.download-card {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  border-radius: 24px;
  padding: 56px 40px;
  text-align: center;
  color: #fff;
  box-shadow: 0 20px 50px rgba(255, 122, 69, .25);
}
.download-card h1 { font-size: 34px; font-weight: 800; }
.download-card h1 .ver { color: #FFE3D4; }
.download-meta { margin-top: 12px; font-size: 14px; color: rgba(255, 255, 255, .85); }
.download-btns { display: flex; justify-content: center; gap: 18px; margin-top: 30px; flex-wrap: wrap; }
.btn-white { background: #fff; color: var(--primary); }
.btn-white:hover { box-shadow: 0 10px 24px rgba(0, 0, 0, .15); }
.btn-ghost { background: rgba(255, 255, 255, .16); color: #fff; border: 1px solid rgba(255, 255, 255, .5); }
.btn-ghost:hover { background: rgba(255, 255, 255, .26); }
.download-tip { margin-top: 26px; font-size: 14px; color: rgba(255, 255, 255, .92); }

/* ===== 页脚 ===== */
.footer { background: var(--dark); color: #A8B0BC; text-align: center; padding: 26px 20px; font-size: 13.5px; }
.footer a { color: #fff; font-weight: 600; }

/* ===== 返回顶部 ===== */
.back-top {
  position: fixed;
  right: 26px;
  bottom: 30px;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: var(--card);
  border: 1px solid var(--border);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity .3s ease, transform .3s ease, visibility .3s ease, background .3s ease;
  z-index: 90;
}
.back-top.show { opacity: 1; visibility: visible; transform: none; }
.back-top:hover { background: var(--primary); color: #fff; }
.back-top svg { width: 20px; height: 20px; }

/* ===== 平板适配 ===== */
@media (max-width: 1024px) {
  .works-grid { grid-template-columns: repeat(2, 1fr); }
  .features-grid, .reviews-grid, .data-grid { grid-template-columns: repeat(2, 1fr); }
  .hero h1 { font-size: 36px; }
  .hero-inner { gap: 36px; }
  .nav a { padding: 5px 8px; font-size: 13px; }
}

/* ===== 移动端适配 ===== */
@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; text-align: center; }
  .hero-desc { margin-left: auto; margin-right: auto; }
  .hero-btns { justify-content: center; }
  .hero-img { max-width: 520px; margin: 0 auto; width: 100%; }
}

@media (max-width: 760px) {
  .nav { display: none; }
}

@media (max-width: 640px) {
  .container { padding: 0 20px; }
  .section { padding: 52px 0; }
  .section-title { font-size: 24px; }
  .hero { padding-top: calc(var(--nav-h) + 28px); }
  .hero h1 { font-size: 29px; }
  .hero-btns { flex-direction: column; width: 100%; }
  .hero-btns .btn { width: 100%; padding: 14px; }
  .works-grid, .features-grid, .reviews-grid { grid-template-columns: 1fr; }
  .data-grid { grid-template-columns: repeat(2, 1fr); gap: 14px; }
  .data-num { font-size: 30px; }
  .intro-card { padding: 30px 22px; }
  .intro-points { grid-template-columns: 1fr; gap: 12px; }
  .compare-row { grid-template-columns: 1fr 1fr; }
  .compare-row.head { display: none; }
  .compare-item { grid-column: 1 / -1; background: var(--bg); padding: 12px 18px; font-size: 14px; }
  .compare-cell { padding: 14px 18px; }
  .compare-us { background: rgba(255, 122, 69, .05); }
  .version-card { padding: 30px 22px; }
  .faq-question { padding: 18px 20px; font-size: 15px; }
  .faq-answer p { padding: 0 20px 20px; }
  .download-card { padding: 44px 20px; border-radius: 20px; }
  .download-card h1 { font-size: 27px; }
  .download-meta { font-size: 12px; white-space: nowrap; }
  .download-btns { flex-direction: column; width: 100%; }
  .download-btns .btn { width: 100%; }
  .back-top { right: 16px; bottom: 20px; }
}