/* ══════════ 生命互联 · 虚拟外泌体工程实验室 ══════════
   主题：深空生物科技风 × 生命互联橙色主色 */

:root {
  --bg: #0A0D12;
  --bg-2: #10141B;
  --panel: rgba(255,255,255,.04);
  --panel-border: rgba(255,255,255,.09);
  --orange: #FF7A1A;
  --orange-hi: #FF9A45;
  --amber: #FFB25E;
  --cream: #FFD9AE;
  --text: #F2EDE6;
  --muted: #9AA3AF;
  --cyan: #4FD8E8;   /* 辅助冷色：对照/机制 */
  --green: #7ED957;  /* 植物来源 */
  --violet: #B07CFF; /* 微生物来源 */
  --radius: 16px;
  --nav-h: 68px;
}

* { margin:0; padding:0; box-sizing:border-box; }
html { scroll-behavior:smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: "PingFang SC","Microsoft YaHei","Segoe UI",system-ui,sans-serif;
  line-height:1.6;
  overflow-x:hidden;
}
::selection { background:var(--orange); color:#14100B; }

.container { max-width:1240px; margin:0 auto; padding:0 28px; }
section { position:relative; }

/* ── 通用组件 ── */
.btn {
  display:inline-flex; align-items:center; gap:8px;
  padding:12px 26px; border-radius:999px;
  font-size:15px; font-weight:600; text-decoration:none;
  border:1px solid transparent; cursor:pointer;
  transition:.25s ease; white-space:nowrap;
}
.btn-primary {
  background:linear-gradient(135deg,var(--orange),#FF5E00);
  color:#fff;
  box-shadow:0 4px 24px rgba(255,122,26,.35);
}
.btn-primary:hover { transform:translateY(-2px); box-shadow:0 8px 32px rgba(255,122,26,.55); }
.btn-ghost {
  border-color:rgba(255,178,94,.4); color:var(--amber);
  background:rgba(255,122,26,.06);
}
.btn-ghost:hover { background:rgba(255,122,26,.14); border-color:var(--amber); }
.btn-lg { padding:15px 34px; font-size:16px; }
.arrow { transition:.25s; }
.btn:hover .arrow { transform:translateX(4px); }

.kicker { font-size:13px; letter-spacing:.35em; color:var(--orange); font-weight:700; text-transform:uppercase; }
.sec-head { text-align:center; max-width:820px; margin:0 auto 56px; }
.sec-head h2 { font-size:clamp(28px,4vw,42px); font-weight:800; margin:14px 0 12px; }
.sec-head p { color:var(--muted); font-size:16px; }

.grad-orange {
  background:linear-gradient(120deg,var(--orange) 10%,var(--cream) 90%);
  -webkit-background-clip:text; background-clip:text; color:transparent;
}

/* 滚动显现 */
.reveal { opacity:0; transform:translateY(28px); transition:.8s cubic-bezier(.2,.7,.2,1); }
.reveal.in { opacity:1; transform:none; }
.d1{transition-delay:.1s}.d2{transition-delay:.2s}.d3{transition-delay:.3s}.d4{transition-delay:.45s}

/* ── 导航 ── */
.nav {
  position:fixed; top:0; left:0; right:0; z-index:100;
  height:var(--nav-h);
  background:rgba(10,13,18,.72);
  backdrop-filter:blur(16px); -webkit-backdrop-filter:blur(16px);
  border-bottom:1px solid rgba(255,255,255,.06);
  transition:.3s;
}
.nav.scrolled { background:rgba(10,13,18,.92); box-shadow:0 4px 30px rgba(0,0,0,.4); }
.nav-inner { max-width:1320px; margin:0 auto; height:100%; padding:0 28px; display:flex; align-items:center; gap:36px; }
.logo { display:flex; align-items:center; gap:11px; text-decoration:none; color:var(--text); flex-shrink:0; }
.official-logo { display:block; width:auto; height:42px; }
.logo-module { font-size:13px; color:var(--muted); white-space:nowrap; }
.logo-text {
  font-family:'Helvetica Neue','Inter',Arial,"PingFang SC","Microsoft YaHei",sans-serif;
  font-size:18px; font-weight:400; letter-spacing:.04em;
  display:flex; align-items:baseline; gap:9px;
}
.logo-cn { font-weight:700; letter-spacing:.14em; font-size:16.5px; }
.nav-menu { display:flex; gap:28px; margin-left:auto; }
.nav-menu a { color:var(--muted); text-decoration:none; font-size:14.5px; position:relative; padding:6px 0; transition:.2s; }
.nav-menu a:hover, .nav-menu a.active { color:var(--text); }
.nav-menu a.active::after {
  content:""; position:absolute; left:0; right:0; bottom:-2px; height:2px;
  background:var(--orange); border-radius:2px; box-shadow:0 0 10px var(--orange);
}
.nav .btn-nav { margin-left:8px; padding:9px 20px; font-size:13.5px; }
.nav-toggle { display:none; background:none; border:none; color:var(--text); font-size:22px; cursor:pointer; margin-left:auto; }

@media (max-width:900px) {
  .official-logo { height:36px; }
  .logo-module { display:none; }
  .nav-menu, .nav .btn-nav { display:none; }
  .nav-toggle { display:block; }
  .nav.open .nav-menu {
    display:flex; flex-direction:column; gap:4px;
    position:absolute; top:var(--nav-h); left:0; right:0;
    background:rgba(12,15,21,.98); padding:16px 28px 20px;
    border-bottom:1px solid var(--panel-border);
  }
  .nav.open .btn-nav { display:inline-flex; position:absolute; top:calc(var(--nav-h) + 210px); left:28px; }
}

/* ── 第一屏 ── */
.hero {
  min-height:100vh; display:flex; align-items:center;
  padding-top:var(--nav-h);
  overflow:hidden;
  background:
    radial-gradient(1100px 600px at 78% 18%, rgba(255,122,26,.13), transparent 60%),
    radial-gradient(900px 700px at 12% 85%, rgba(79,216,232,.05), transparent 60%),
    var(--bg);
}
#heroCanvas { position:absolute; inset:0; width:100%; height:100%; }
.hero-glow {
  position:absolute; width:520px; height:520px; border-radius:50%;
  right:6%; top:50%; transform:translateY(-50%);
  background:radial-gradient(circle, rgba(255,122,26,.16), transparent 65%);
  filter:blur(40px); pointer-events:none;
  animation:breathe 6s ease-in-out infinite;
}
.hero-ev-card {
  position:absolute; z-index:3; right:3%; top:17%;
  width:258px; padding:15px 17px; border-radius:15px;
  background:rgba(7,11,17,.76); border:1px solid rgba(79,216,232,.18);
  backdrop-filter:blur(12px); box-shadow:0 18px 50px rgba(0,0,0,.32); pointer-events:none;
}
.hero-ev-card > span { color:var(--cyan); font-size:9.5px; letter-spacing:.18em; font-weight:800; }
.hero-ev-card > b { display:block; margin:3px 0 9px; font-size:14px; }
.hero-ev-card > div { display:flex; align-items:center; gap:8px; margin:5px 0; color:#C5CDD5; font-size:11px; }
.hero-ev-card i { width:7px; height:7px; border-radius:50%; box-shadow:0 0 9px currentColor; }
.hero-ev-card i.inside { color:#4FD8E8; background:#4FD8E8; }
.hero-ev-card i.outside { color:#B07CFF; background:#B07CFF; }
.hero-ev-card small { display:block; margin-top:9px; padding-top:8px; border-top:1px solid rgba(255,255,255,.07); color:var(--amber); font-size:10.5px; }
@keyframes breathe { 0%,100%{opacity:.7} 50%{opacity:1.1} }
.hero-content { position:relative; z-index:2; max-width:720px; padding:60px 28px 80px; margin-left:max(28px, calc((100% - 1240px)/2)); }
.hero-kicker { font-size:13px; letter-spacing:.4em; color:var(--orange); font-weight:700; }
.hero h1 { font-size:clamp(38px,5.6vw,64px); font-weight:800; line-height:1.18; margin:18px 0 20px; letter-spacing:.01em; }
.hero-sub { font-size:17px; color:var(--muted); margin-bottom:34px; }
.hero-actions { display:flex; gap:16px; flex-wrap:wrap; }
.hero-stats { display:flex; gap:0; margin-top:56px; border-top:1px solid var(--panel-border); padding-top:26px; flex-wrap:wrap; }
.hero-stats > div { flex:1; min-width:150px; padding-right:24px; }
.hero-stats b { display:block; font-size:22px; color:var(--orange); font-weight:800; }
.hero-stats span { font-size:12.5px; color:var(--muted); }
.scroll-hint {
  position:absolute; bottom:26px; left:50%; width:24px; height:40px;
  border:2px solid rgba(255,178,94,.4); border-radius:14px; z-index:2;
}
.scroll-hint span {
  position:absolute; top:7px; left:50%; width:4px; height:9px; margin-left:-2px;
  background:var(--amber); border-radius:3px;
  animation:scrollDot 1.8s infinite;
}
@keyframes scrollDot { 0%{opacity:1;transform:translateY(0)} 70%{opacity:0;transform:translateY(14px)} 100%{opacity:0} }
.m-br { display:block; } @media(min-width:769px){ .m-br{display:inline} }
@media (max-width:1080px){ .hero-ev-card{display:none;} }
@media (max-width:640px){
  .hero h1 { font-size:34px; line-height:1.16; }
  .hero-sub { font-size:15px; line-height:1.75; }
  .hero-content { padding-top:52px; }
}

/* ── 定位声明条 ── */
.positioning { border-block:1px solid var(--panel-border); background:var(--bg-2); }
.positioning-inner { padding:44px 28px; display:flex; align-items:center; justify-content:space-between; gap:24px; flex-wrap:wrap; }
.positioning-inner p { font-size:clamp(17px,2.2vw,21px); font-weight:600; }
.positioning-inner b { color:var(--orange); }
.tagline-sub { color:var(--muted); font-size:14px; letter-spacing:.08em; }