/* PoLang 官网 · 深色科技感主题（与 App 主色一致：薄荷系，增强电子青光效） */
:root {
  --bg: #020a0e;
  --bg-alt: #041218;
  --card: #081c22;
  --footer: #030e13;
  --text: #eaf7f4;
  --text-soft: #9fc6c4;
  --text-muted: #6f9aa0;
  --border: rgba(127, 231, 210, .22);
  --border-soft: rgba(127, 231, 210, .10);
  --primary: #7fe7d2;
  --on-primary: #003730;
  --primary-soft: rgba(127, 231, 210, .10);
  --primary-glow: rgba(127, 231, 210, .45);
  --cyan: #38bdf8;
  --danger: #f2b8c6;
  --radius: 16px;
  --shadow-md: 0 18px 44px rgba(0, 0, 0, .45);
  --section-py: 72px;
}
* { 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: 1.7;
  -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale;
}
/* 科技感背景：顶部电子青光晕 + 双侧青蓝光束 + 细网格 */
body::before {
  content: ""; position: fixed; inset: 0; z-index: -1; pointer-events: none;
  background:
    radial-gradient(62% 42% at 50% -6%, rgba(127, 231, 210, .20), transparent 70%),
    radial-gradient(38% 30% at 92% 18%, rgba(56, 189, 248, .12), transparent 70%),
    radial-gradient(32% 26% at 6% 30%, rgba(127, 231, 210, .08), transparent 70%),
    linear-gradient(rgba(127, 231, 210, .05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(127, 231, 210, .05) 1px, transparent 1px);
  background-size: auto, auto, auto, 48px 48px, 48px 48px;
}
a { color: inherit; text-decoration: none; }
.container { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* 顶栏 */
.topnav { position: sticky; top: 0; z-index: 20; background: rgba(2, 10, 14, .78); backdrop-filter: saturate(160%) blur(14px); -webkit-backdrop-filter: saturate(160%) blur(14px); border-bottom: 1px solid var(--border-soft); }
.topnav-inner { display: flex; align-items: center; justify-content: space-between; height: 62px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 17px; letter-spacing: -.01em; }
.brand img { width: 30px; height: 30px; border-radius: 8px; }
.nav-links { display: flex; align-items: center; gap: 22px; font-size: 14px; color: var(--text-muted); font-weight: 500; }
.nav-links a { transition: color .12s; }
.nav-links a:hover { color: var(--primary); }
.lang-switch { border: 1px solid var(--border); border-radius: 999px; padding: 4px 12px; color: var(--text-soft); }
.lang-switch:hover { border-color: var(--primary); color: var(--primary); }

/* Hero */
.hero { padding: 84px 24px 64px; text-align: center; position: relative; }
.hero .eyebrow { display: inline-flex; align-items: center; gap: 8px; color: var(--primary); background: var(--primary-soft); border: 1px solid var(--border); border-radius: 999px; padding: 6px 16px; font-size: 13px; font-weight: 600; letter-spacing: .08em; font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; box-shadow: 0 0 24px rgba(127, 231, 210, .10), inset 0 0 12px rgba(127, 231, 210, .06); }
.hero .eyebrow::before { content: ""; width: 7px; height: 7px; border-radius: 999px; background: var(--primary); box-shadow: 0 0 12px var(--primary-glow); }
.hero h1 { font-size: 54px; line-height: 1.12; letter-spacing: -.03em; font-weight: 800; margin: 26px 0 16px; }
.hero h1 .mint { color: var(--primary); text-shadow: 0 0 32px var(--primary-glow); }
.hero .tagline { font-size: 18px; color: var(--text-soft); max-width: 660px; margin: 0 auto; }
.badges { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; margin: 28px 0 34px; }
.badge { background: var(--primary-soft); color: var(--primary); border: 1px solid var(--border); border-radius: 999px; padding: 6px 14px; font-size: 13px; font-weight: 600; }
.cta-row { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 13px 24px; border-radius: 12px; font-weight: 600; font-size: 15px; transition: transform .12s, box-shadow .12s, border-color .12s, background .12s; border: 1px solid var(--border); color: var(--text); background: rgba(10, 31, 27, .6); }
.btn:hover { transform: translateY(-1px); border-color: var(--primary); box-shadow: 0 10px 28px rgba(0, 0, 0, .4); }
.btn.primary { background: var(--primary); color: var(--on-primary); border-color: transparent; box-shadow: 0 10px 34px rgba(127, 231, 210, .38); }
.btn.primary:hover { box-shadow: 0 14px 44px rgba(127, 231, 210, .55); }
.btn svg { width: 20px; height: 20px; flex-shrink: 0; }

/* 区块通用 */
section { padding: var(--section-py) 0; }
.alt { background: var(--bg-alt); border-top: 1px solid var(--border-soft); border-bottom: 1px solid var(--border-soft); }
.eyebrow-sm { display: block; text-align: center; color: var(--primary); font-size: 13px; font-weight: 700; letter-spacing: .18em; text-transform: uppercase; margin-bottom: 12px; font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; text-shadow: 0 0 18px rgba(127, 231, 210, .35); }
.section-title { font-size: 34px; font-weight: 800; text-align: center; letter-spacing: -.02em; margin-bottom: 12px; }
.section-sub { text-align: center; color: var(--text-muted); font-size: 16px; margin-bottom: 34px; }

/* 核心功能 */
.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.card { background: var(--card); border: 1px solid var(--border-soft); border-radius: var(--radius); padding: 26px 24px; transition: border-color .18s, transform .18s, box-shadow .18s; }
.card:hover { border-color: var(--border); transform: translateY(-3px); box-shadow: var(--shadow-md); }
.card .icon { width: 46px; height: 46px; border-radius: 12px; background: var(--primary-soft); border: 1px solid var(--border); display: flex; align-items: center; justify-content: center; font-size: 22px; }
.card h3 { font-size: 17px; font-weight: 700; margin: 16px 0 8px; }
.card p { font-size: 14.5px; color: var(--text-muted); line-height: 1.65; }

/* 一眼所见(截图)：桌面两排各 4 张（grid，撑满列宽），移动端横向滑动 */
.shots { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.shots img { width: 100%; height: auto; border-radius: 16px; border: 1px solid var(--border); box-shadow: var(--shadow-md), 0 0 0 6px rgba(127, 231, 210, .04); }

/* 使用示例 */
.demo-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.demo-card { background: var(--card); border: 1px solid var(--border-soft); border-radius: var(--radius); padding: 22px 24px; transition: border-color .18s; }
.demo-card:hover { border-color: var(--border); }
.demo-card .say { font-size: 15px; color: var(--primary); font-weight: 600; margin-bottom: 8px; }
.demo-card .say::before { content: "💬 "; }
.demo-card .do { font-size: 14.5px; color: var(--text-muted); }

/* 开源区块 */
.oss-card { max-width: 880px; margin: 0 auto; text-align: center; background: linear-gradient(160deg, rgba(127, 231, 210, .10), rgba(10, 31, 27, .6) 55%); border: 1px solid var(--border); border-radius: 24px; padding: 52px 40px; position: relative; overflow: hidden; }
.oss-card::before { content: ""; position: absolute; inset: -40% 30% auto; height: 240px; background: radial-gradient(closest-side, var(--primary-glow), transparent); opacity: .35; pointer-events: none; }
.oss-card h2 { font-size: 30px; font-weight: 800; letter-spacing: -.02em; margin-bottom: 14px; }
.oss-card p { color: var(--text-soft); font-size: 16px; max-width: 620px; margin: 0 auto 26px; }

/* 最终 CTA */
.final-cta { text-align: center; padding: calc(var(--section-py) + 12px) 0; position: relative; }
.final-cta::before { content: ""; position: absolute; left: 50%; top: 0; transform: translateX(-50%); width: 640px; max-width: 90vw; height: 320px; background: radial-gradient(closest-side, rgba(127, 231, 210, .16), transparent); pointer-events: none; }
.final-cta h2 { font-size: 38px; font-weight: 800; letter-spacing: -.02em; margin-bottom: 14px; position: relative; }
.final-cta p { color: var(--text-muted); margin-bottom: 30px; position: relative; }
.final-cta .cta-row { position: relative; }

/* 常见问题 */
.faq { max-width: 760px; margin: 0 auto; }
.faq-item { border-bottom: 1px solid var(--border-soft); padding: 20px 0; }
.faq-item:first-child { padding-top: 0; }
.faq-item:last-child { border-bottom: none; padding-bottom: 0; }
.faq-item h3 { font-size: 16.5px; font-weight: 700; margin-bottom: 8px; }
.faq-item p { font-size: 14.5px; color: var(--text-muted); line-height: 1.7; }
.faq-item a { color: var(--primary); font-weight: 500; }

/* 页脚 */
footer { background: var(--footer); color: var(--text-muted); padding: 44px 0; border-top: 1px solid var(--border-soft); }
footer .inner { display: flex; flex-wrap: wrap; gap: 16px; justify-content: space-between; align-items: center; }
footer .nav-links a:hover { color: var(--primary); }
footer .contact-author { display: flex; flex-direction: column; align-items: center; gap: 12px; margin-bottom: 30px; }
footer .contact-title { font-size: 13px; color: var(--text-muted); letter-spacing: .08em; }
footer .contact-items { display: flex; gap: 36px; align-items: flex-start; }
footer .contact-item { display: flex; flex-direction: column; align-items: center; gap: 8px; font-size: 12px; color: var(--text-muted); transition: color .12s; }
footer .contact-item:hover { color: var(--primary); }
footer .contact-qr { width: 88px; height: 88px; border-radius: 10px; background: #fff; padding: 4px; box-sizing: border-box; display: block; }
footer .x-logo { width: 88px; height: 88px; border-radius: 10px; background: #fff; display: flex; align-items: center; justify-content: center; }
footer .x-logo svg { width: 56px; height: 56px; }

/* 上手指南轮播 */
.guide-carousel { position: relative; max-width: 880px; margin: 0 auto; }
.guide-viewport { overflow: hidden; border-radius: var(--radius); box-shadow: var(--shadow-md); }
.guide-track { display: flex; transition: transform .55s cubic-bezier(.4, 0, .2, 1); will-change: transform; }
.guide-slide { min-width: 100%; display: flex; align-items: center; gap: 32px; padding: 30px 34px; background: linear-gradient(120deg, #0a1f1b 48%, #0d2a24 100%); border: 1px solid var(--border-soft); box-sizing: border-box; }
.guide-slide > img { height: 400px; width: auto; flex-shrink: 0; border-radius: 14px; border: 1px solid var(--border); box-shadow: var(--shadow-md); display: block; }
.guide-cap { flex: 1 1 auto; min-width: 0; }
.guide-cap .gs { display: inline-flex; align-items: center; gap: 7px; color: var(--on-primary); background: var(--primary); border-radius: 999px; padding: 6px 15px; font-size: 13px; font-weight: 700; margin-bottom: 14px; box-shadow: 0 6px 18px rgba(127, 231, 210, .3); letter-spacing: .02em; }
.guide-cap .gs::before { content: ""; width: 6px; height: 6px; border-radius: 999px; background: var(--on-primary); opacity: .9; }
.guide-cap h3 { font-size: 23px; font-weight: 800; margin-bottom: 10px; letter-spacing: -.01em; color: var(--text); }
.guide-cap p { font-size: 15px; color: var(--text-soft); line-height: 1.75; }
.guide-cap p b { color: var(--primary); font-weight: 700; }
.guide-cap .gtags { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 14px; }
.guide-cap .gtag { background: rgba(3, 13, 11, .5); color: var(--text-soft); border: 1px solid var(--border-soft); border-radius: 999px; padding: 4px 12px; font-size: 12px; font-weight: 600; }
.guide-cap .gtag.must { background: rgba(242, 184, 198, .10); color: var(--danger); border-color: rgba(242, 184, 198, .22); }
.guide-cap .gtag.opt { background: var(--primary-soft); color: var(--primary); border-color: var(--border); }
.guide-arrow { position: absolute; top: 50%; transform: translateY(-50%); width: 42px; height: 42px; border-radius: 999px; border: 1px solid var(--border); background: var(--card); cursor: pointer; font-size: 22px; line-height: 1; color: var(--text-soft); display: flex; align-items: center; justify-content: center; z-index: 2; transition: border-color .15s, color .15s, transform .15s; }
.guide-arrow:hover { border-color: var(--primary); color: var(--primary); transform: translateY(-50%) scale(1.06); }
.guide-prev { left: 10px; } .guide-next { right: 10px; }
.guide-dots { display: flex; gap: 7px; justify-content: center; margin-top: 20px; }
.guide-dots button { width: 8px; height: 8px; border-radius: 999px; border: none; background: rgba(127, 231, 210, .22); cursor: pointer; padding: 0; transition: background .2s, width .2s; }
.guide-dots button.on { background: var(--primary); width: 24px; }
.guide-more { text-align: center; margin-top: 6px; }
.guide-more a { color: var(--primary); font-weight: 600; font-size: 14px; }
.guide-more a:hover { text-decoration: underline; }

/* 图片放大查看（灯箱） */
.lightbox { position: fixed; inset: 0; background: rgba(2, 8, 7, .95); display: none; align-items: center; justify-content: center; z-index: 999; padding: 18px; cursor: zoom-out; }
.lightbox.show { display: flex; }
.lightbox img { max-width: 100%; max-height: 100%; object-fit: contain; border-radius: 10px; box-shadow: 0 20px 60px rgba(0, 0, 0, .6); }

@media (max-width: 768px) {
  :root { --section-py: 48px; }
  .container { padding: 0 18px; }
  .hero { padding: 52px 18px 44px; }
  .hero h1 { font-size: 32px; }
  .hero .tagline { font-size: 16px; }
  .section-title { font-size: 25px; }
  .section-sub { font-size: 15px; margin-bottom: 26px; }
  .grid, .demo-grid { grid-template-columns: 1fr; }
  .shots { display: flex; flex-wrap: nowrap; justify-content: flex-start; overflow-x: auto; padding-bottom: 10px; scroll-snap-type: x mandatory; -webkit-overflow-scrolling: touch; scrollbar-width: none; }
  .shots img { width: auto; height: 340px; flex-shrink: 0; }
  .shots::-webkit-scrollbar { display: none; }
  .shots img { height: 340px; scroll-snap-align: center; }
  .nav-links { gap: 12px; font-size: 13px; }
  .nav-sm-hide { display: none; }
  .guide-slide { flex-direction: column; text-align: center; gap: 16px; padding: 22px 18px; }
  .guide-slide > img { height: 300px; }
  .guide-arrow { display: none; }
  .guide-cap .gtags { justify-content: center; }
  .cta-row { flex-direction: column; align-items: stretch; }
  .oss-card { padding: 38px 22px; }
  .oss-card h2 { font-size: 24px; }
  .final-cta h2 { font-size: 28px; }
}

/* 竞品对比表 */
.cmp-wrap { overflow-x: auto; }
.cmp { width: 100%; border-collapse: collapse; font-size: 15px; }
.cmp th, .cmp td { padding: 12px 14px; text-align: left; border-bottom: 1px solid var(--border-soft); white-space: nowrap; }
.cmp th { color: var(--text); font-weight: 600; }
.cmp td { color: var(--text-soft); }
.cmp td:first-child, .cmp th:first-child { color: var(--text); font-weight: 500; }
.cmp .yes { color: var(--primary); }