/* ============================================================
   DENSITY-SR · 阿尔法量化 官网
   深色金融终端美学 · 橙色品牌
   ============================================================ */

:root {
  --bg-0: #050505;
  --bg-1: #0a0a0a;
  --bg-2: #111111;
  --bg-3: #1a1a1a;
  --line: rgba(249,115,22,.18);
  --line-2: rgba(249,115,22,.40);
  --text: #F5F5F5;
  --text-2: #B8B8B8;
  --text-3: #737373;
  --brand: #F97316;
  --brand-2: #FB923C;
  --brand-3: #FBBF24;
  --down:  #EF4444;   /* 跌 - 红 */
  --up:    #10B981;   /* 涨 - 绿（A股惯例） */
  --warn:  #F59E0B;
  --shadow-1: 0 12px 40px rgba(249,115,22,.18);
  --shadow-2: 0 24px 64px rgba(251,146,60,.22);
  --mono: 'JetBrains Mono','Fira Code','Cascadia Code',Consolas,Menlo,monospace;
  --radius: 12px;
  --container: 1180px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI",
               "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg-1);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img, svg { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; border: none; background: none; color: inherit; }

/* ============ 背景：深色终端 + 扫描线 ============ */
.bg-fx {
  position: fixed; inset: 0; z-index: -1; pointer-events: none;
  background:
    radial-gradient(900px 500px at 15% -10%, rgba(249,115,22,.14), transparent 60%),
    radial-gradient(800px 600px at 100% 20%, rgba(251,146,60,.08), transparent 65%),
    linear-gradient(180deg, #0a0a0a 0%, #050505 100%);
}
.bg-fx::after {
  content: ""; position: absolute; inset: 0;
  background-image: linear-gradient(180deg, transparent 0%, transparent 50%, rgba(255,255,255,.012) 50%, transparent 51%);
  background-size: 100% 4px;
  opacity: .4;
}

/* ============ 导航 ============ */
.nav {
  position: sticky; top: 0; z-index: 100;
  backdrop-filter: blur(14px);
  background: rgba(10,10,10,.75);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: var(--container); margin: 0 auto;
  padding: 14px 28px;
  display: flex; align-items: center; justify-content: space-between;
}
.nav-brand img { height: 44px; }
.nav-links {
  display: flex; gap: 30px; align-items: center;
  font-size: 14px; color: var(--text-2);
}
.nav-links a { transition: color .15s; }
.nav-links a:hover { color: var(--brand); }
.nav-cta {
  padding: 9px 18px; border-radius: 8px;
  background: var(--brand); color: #000; font-weight: 700;
  transition: transform .15s, box-shadow .15s;
}
.nav-cta:hover { transform: translateY(-1px); box-shadow: var(--shadow-1); }
@media (max-width: 760px) { .nav-links { display: none; } }

/* ============ 通用 ============ */
.container { max-width: var(--container); margin: 0 auto; padding: 0 28px; }
.section { padding: 96px 0; position: relative; }
.section-tag {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 6px 14px; border-radius: 4px;
  background: rgba(249,115,22,.1);
  border: 1px solid var(--line-2);
  color: var(--brand); font-size: 12px; letter-spacing: 1.5px;
  text-transform: uppercase; font-family: var(--mono); margin-bottom: 18px;
}
.section-tag::before {
  content: ">"; color: var(--brand-2); font-weight: 700;
}
.section-title {
  font-size: clamp(28px, 4vw, 44px); font-weight: 800;
  color: #fff;
  line-height: 1.2; margin-bottom: 16px;
  letter-spacing: -0.5px;
}
.section-title em {
  font-style: normal;
  color: var(--brand);
  font-family: var(--mono);
}
.section-sub { color: var(--text-2); font-size: 16px; max-width: 720px; }

/* ============ HERO ============ */
.hero {
  padding: 80px 0 56px;
  text-align: center;
  position: relative;
  isolation: isolate;
}
.hero-glow {
  position: absolute; pointer-events: none; z-index: -1;
  width: 560px; height: 560px; border-radius: 50%;
  filter: blur(90px);
  animation: drift 14s ease-in-out infinite alternate;
}
.hero-glow.a { top: -160px; left: -140px; background: rgba(249,115,22,.25); }
.hero-glow.b { top: 80px; right: -160px; background: rgba(251,146,60,.16); animation-delay: -6s; }
@keyframes drift {
  from { transform: translate(0,0) scale(1); }
  to   { transform: translate(40px,30px) scale(1.12); }
}
.hero-eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 8px 18px; border-radius: 4px;
  background: var(--bg-2); border: 1px solid var(--line-2);
  color: var(--brand); font-size: 13px;
  font-family: var(--mono);
  margin-bottom: 24px;
}
.hero-eyebrow::before {
  content: ""; width: 8px; height: 8px; border-radius: 50%;
  background: var(--up); box-shadow: 0 0 10px var(--up);
  animation: pulse 1.6s ease-in-out infinite;
}
@keyframes pulse { 0%,100%{opacity:1} 50%{opacity:.4} }
.hero-title {
  font-size: clamp(40px, 7vw, 72px);
  font-weight: 900; color: #fff;
  letter-spacing: -1px; line-height: 1.05;
  margin-bottom: 18px;
}
.hero-title em {
  font-style: normal; font-family: var(--mono);
  background: linear-gradient(135deg, var(--brand) 0%, var(--brand-3) 100%);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-subtitle {
  font-size: clamp(18px, 2.5vw, 26px);
  color: var(--text-2); margin-bottom: 18px;
  font-family: var(--mono);
}
.hero-desc {
  font-size: 17px; color: var(--text-2);
  max-width: 720px; margin: 0 auto 36px;
}
.hero-ctas {
  display: flex; gap: 16px; justify-content: center; flex-wrap: wrap;
  margin-bottom: 24px;
}
.btn-primary {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 16px 32px; border-radius: 10px;
  background: var(--brand); color: #000; font-weight: 800; font-size: 16px;
  transition: transform .15s, box-shadow .15s;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: var(--shadow-1); }
.btn-ghost {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 16px 28px; border-radius: 10px;
  background: var(--bg-2);
  border: 1px solid var(--line-2);
  color: var(--text); font-weight: 600; font-size: 16px;
  font-family: var(--mono);
  transition: all .15s;
}
.btn-ghost:hover { background: var(--bg-3); border-color: var(--brand); }
.hero-meta {
  color: var(--text-3); font-size: 13px;
  display: inline-flex; gap: 14px; align-items: center;
  font-family: var(--mono);
}
.hero-meta .dot { width: 4px; height: 4px; background: var(--text-3); border-radius: 50%; }
.hero-mock {
  margin-top: 56px; position: relative;
  border-radius: var(--radius);
  background: var(--bg-2);
  border: 1px solid var(--line-2);
  padding: 12px;
  box-shadow: var(--shadow-2);
}
.hero-mock img { border-radius: 6px; width: 100%; }
.hero-mock-cap {
  position: absolute; bottom: 26px; left: 26px;
  padding: 6px 12px; border-radius: 4px;
  background: rgba(0,0,0,.7); color: var(--brand);
  font-size: 12px; font-family: var(--mono);
  border: 1px solid var(--line-2);
}

/* ============ 数据条（终端风） ============ */
.stats {
  margin-top: 64px;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px;
  font-family: var(--mono);
}
.stat-card {
  padding: 20px;
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color .15s;
}
.stat-card:hover { border-color: var(--brand); }
.stat-num {
  font-size: 30px; font-weight: 800; color: var(--brand);
  font-family: var(--mono);
}
.stat-label { color: var(--text-3); font-size: 12px; margin-top: 4px; letter-spacing: .5px; }
@media (max-width: 720px) { .stats { grid-template-columns: repeat(2, 1fr); } }

/* ============ 功能网格 ============ */
.features {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px;
  margin-top: 56px;
}
.feat {
  padding: 24px;
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform .2s, border-color .2s, background .2s;
}
.feat:hover {
  transform: translateY(-4px);
  border-color: var(--brand);
  background: linear-gradient(180deg, rgba(249,115,22,.06), var(--bg-2));
}
.feat-ico {
  width: 42px; height: 42px; border-radius: 8px;
  display: grid; place-items: center; margin-bottom: 14px;
  background: rgba(249,115,22,.12);
  border: 1px solid var(--line-2);
  color: var(--brand);
}
.feat h3 { font-size: 17px; margin-bottom: 8px; color: #fff; }
.feat p { color: var(--text-2); font-size: 14px; }
.feat .feat-meta {
  margin-top: 12px;
  font-family: var(--mono); font-size: 11px;
  color: var(--brand); letter-spacing: .5px;
}
@media (max-width: 900px) { .features { grid-template-columns: 1fr; } }

/* ============ 截图 tabs ============ */
.gallery-tabs {
  display: flex; gap: 6px; flex-wrap: wrap;
  margin: 32px 0 16px; justify-content: center;
  font-family: var(--mono);
}
.gallery-tab {
  padding: 8px 16px; border-radius: 6px;
  background: var(--bg-2);
  border: 1px solid var(--line);
  color: var(--text-2); font-size: 13px;
  transition: all .15s;
}
.gallery-tab.active, .gallery-tab:hover {
  background: var(--brand); color: #000; border-color: var(--brand);
}
.gallery-stage {
  position: relative; border-radius: var(--radius);
  background: var(--bg-2);
  border: 1px solid var(--line);
  padding: 12px; overflow: hidden;
}
.gallery-frame {
  border-radius: 6px; overflow: hidden;
  background: #000; aspect-ratio: 16/10;
}
.gallery-frame img {
  width: 100%; height: 100%; object-fit: cover;
  transition: opacity .35s;
}
.gallery-caption {
  margin-top: 12px; color: var(--text-2); font-size: 13px;
  text-align: center; font-family: var(--mono);
}

/* ============ 数据流 / pipeline ============ */
.pipeline {
  display: grid; grid-template-columns: 1fr; gap: 0;
  margin-top: 48px;
  border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--bg-2); overflow: hidden;
  font-family: var(--mono);
}
.pipe-row {
  display: grid; grid-template-columns: 56px 1fr;
  align-items: stretch;
  border-bottom: 1px solid var(--line);
}
.pipe-row:last-child { border-bottom: none; }
.pipe-num {
  display: grid; place-items: center;
  background: var(--brand); color: #000; font-weight: 800; font-size: 18px;
}
.pipe-body { padding: 18px 22px; }
.pipe-body h4 { font-size: 15px; margin-bottom: 4px; color: #fff; }
.pipe-body p { color: var(--text-2); font-size: 13px; }
.pipe-body code {
  display: inline-block; margin-top: 6px;
  padding: 2px 8px; border-radius: 4px;
  background: rgba(249,115,22,.12);
  color: var(--brand); font-size: 12px;
}

/* ============ 下载 CTA ============ */
.download {
  position: relative;
  padding: 72px 48px;
  border-radius: var(--radius);
  background:
    radial-gradient(700px 380px at 20% 0%, rgba(249,115,22,.20), transparent 60%),
    radial-gradient(700px 380px at 100% 100%, rgba(251,146,60,.14), transparent 60%),
    var(--bg-2);
  border: 1px solid var(--line-2);
  text-align: center;
  overflow: hidden;
}
.download h2 { font-size: clamp(26px, 4vw, 38px); margin-bottom: 12px; }
.download h2 em { font-style: normal; font-family: var(--mono); color: var(--brand); }
.download p { color: var(--text-2); margin-bottom: 32px; }
.dl-row {
  display: flex; gap: 16px; justify-content: center; flex-wrap: wrap;
}

/* ---------- 多版本下载卡 ---------- */
.dl-variants {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 8px;
  text-align: left;
  font-family: var(--mono);
}
@media (max-width: 820px) { .dl-variants { grid-template-columns: 1fr; } }

.dl-variant {
  padding: 22px;
  border-radius: var(--radius);
  background: var(--bg-1);
  border: 1px solid var(--line);
  display: flex; flex-direction: column;
  transition: border-color .2s, transform .2s;
}
.dl-variant:hover { border-color: var(--line-2); }
.dl-variant.is-primary {
  border-color: var(--brand);
  background: linear-gradient(180deg, rgba(249,115,22,.07), var(--bg-1));
  box-shadow: var(--shadow-1);
}
.dv-head {
  display: flex; align-items: center; gap: 10px; margin-bottom: 8px;
}
.dv-badge {
  padding: 2px 8px; border-radius: 3px;
  font-size: 10px; font-weight: 700; letter-spacing: 1px;
  background: var(--bg-3); color: var(--text-3);
}
.dl-variant.is-primary .dv-badge { background: var(--brand); color: #000; }
.dv-label { font-size: 15px; font-weight: 700; color: #fff; }
.dv-note {
  color: var(--text-2); font-size: 12.5px; line-height: 1.65;
  margin-bottom: 14px; flex: 1;
}
.dv-meta {
  display: flex; gap: 16px; flex-wrap: wrap;
  color: var(--text-3); font-size: 11px;
  padding-bottom: 14px; margin-bottom: 14px;
  border-bottom: 1px dashed var(--line);
}
.dv-actions { display: flex; }
.dv-main { width: 100%; justify-content: center; }
.dv-alt {
  margin-top: 10px; font-size: 11px; color: var(--text-3);
  display: flex; flex-wrap: wrap; gap: 6px; align-items: center;
}
.dv-alt-label { color: var(--text-3); }
.dv-alt a {
  color: var(--brand); text-decoration: underline;
  text-underline-offset: 2px;
}
.dv-alt a:hover { color: var(--brand-3); }
.dl-card {
  display: inline-flex; align-items: center; gap: 14px;
  padding: 16px 24px; border-radius: 10px;
  background: var(--bg-1);
  border: 1px solid var(--line-2);
  text-align: left; font-family: var(--mono);
}
.dl-ico {
  width: 44px; height: 44px; border-radius: 8px;
  display: grid; place-items: center;
  background: var(--brand); color: #000;
}
.dl-meta-line1 { font-weight: 700; font-size: 15px; color: #fff; }
.dl-meta-line2 { color: var(--text-3); font-size: 11px; margin-top: 2px; }
.dl-btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 28px; border-radius: 10px;
  background: var(--brand); color: #000; font-weight: 800; font-size: 16px;
  box-shadow: var(--shadow-1);
  transition: transform .15s;
}
.dl-btn:hover { transform: translateY(-2px) scale(1.02); }

.dl-notes {
  margin-top: 26px;
  display: inline-flex; flex-wrap: wrap; gap: 14px 24px;
  justify-content: center;
  color: var(--text-3); font-size: 12px;
  font-family: var(--mono);
}
.dl-notes span::before {
  content: "✓"; color: var(--up); margin-right: 6px; font-weight: 700;
}

/* ============ 风险提示（合规必需） ============ */
.disclaimer {
  margin-top: 64px;
  padding: 24px 28px;
  border-left: 3px solid var(--warn);
  background: rgba(245,158,11,.04);
  border-radius: 6px;
  font-family: var(--mono);
}
.disclaimer h4 {
  color: var(--warn); font-size: 13px;
  letter-spacing: 1px; margin-bottom: 10px;
  text-transform: uppercase;
}
.disclaimer h4::before { content: "⚠ "; }
.disclaimer p { color: var(--text-2); font-size: 13px; line-height: 1.7; }
.disclaimer p + p { margin-top: 8px; }

/* ============ FAQ ============ */
.faq { margin-top: 56px; max-width: 820px; margin-left: auto; margin-right: auto; }
.faq details {
  border: 1px solid var(--line); border-radius: 8px;
  background: var(--bg-2);
  margin-bottom: 10px; overflow: hidden;
  transition: border-color .15s;
}
.faq details[open] { border-color: var(--line-2); background: var(--bg-3); }
.faq summary {
  padding: 16px 22px; cursor: pointer;
  font-weight: 600; list-style: none;
  display: flex; justify-content: space-between; align-items: center;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::before {
  content: "▸"; color: var(--brand); margin-right: 10px;
  font-family: var(--mono);
}
.faq details[open] summary::before { content: "▾"; }
.faq summary::after {
  content: "+"; color: var(--brand); font-size: 18px;
  transition: transform .2s; font-family: var(--mono);
}
.faq details[open] summary::after { transform: rotate(45deg); }
.faq .ans { padding: 0 22px 16px; color: var(--text-2); font-size: 14px; }

/* ============ Footer ============ */
.footer {
  margin-top: 80px;
  padding: 36px 0 28px;
  border-top: 1px solid var(--line);
  color: var(--text-3); font-size: 12px;
  font-family: var(--mono);
}
.footer-row {
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: 12px;
}
.footer a { color: var(--text-2); }
.footer a:hover { color: var(--brand); }

/* ============ 工具类 ============ */
.text-center { text-align: center; }
.flex-c { display: flex; align-items: center; justify-content: center; }

/* ============ 滚动淡入（无 JS 降级） ============ */
.reveal { transition: opacity .7s cubic-bezier(.2,.7,.3,1), transform .7s cubic-bezier(.2,.7,.3,1); }
.js-reveal .reveal { opacity: 0; transform: translateY(24px); }
.js-reveal .reveal.in { opacity: 1; transform: none; }