:root {
  --bg: #040914; --bg2: #081428; --panel: rgba(14, 28, 54, .55); --panel2: rgba(20, 40, 76, .5);
  --line: rgba(120, 200, 255, .14); --line2: rgba(120, 200, 255, .28);
  --text: #e6f1ff; --muted: #8aa0c0; --dim: #5b6f8e;
  --cyan: #3ee8ff; --green: #4dffb5; --violet: #8b7bff; --pink: #ff6ad5; --amber: #ffc861; --red: #ff6b81;
  --grad: linear-gradient(100deg, var(--cyan), var(--green) 45%, var(--violet));
  --radius: 18px; --shadow: 0 20px 60px rgba(0, 0, 0, .45);
  --font: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  --mono: "JetBrains Mono", "Cascadia Code", Consolas, monospace;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body {
  font-family: var(--font); color: var(--text); background: var(--bg); line-height: 1.7;
  overflow-x: hidden; -webkit-font-smoothing: antialiased;
  background-image: radial-gradient(1200px 700px at 85% -10%, rgba(139, 123, 255, .16), transparent 60%),
    radial-gradient(900px 600px at -10% 30%, rgba(62, 232, 255, .10), transparent 60%),
    radial-gradient(800px 500px at 50% 110%, rgba(77, 255, 181, .08), transparent 60%);
  background-attachment: fixed;
}
a { color: inherit; text-decoration: none; }
button, input, select { font: inherit; color: inherit; }
::selection { background: rgba(62, 232, 255, .35); }
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-thumb { background: rgba(120, 200, 255, .25); border-radius: 8px; }
::-webkit-scrollbar-track { background: transparent; }

#bg { position: fixed; inset: 0; z-index: -1; pointer-events: none; }
.grid-overlay {
  position: fixed; inset: 0; z-index: -1; pointer-events: none; opacity: .35;
  background-image: linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse at 50% 0%, #000 20%, transparent 75%);
}
.cursor-glow {
  position: fixed; width: 520px; height: 520px; border-radius: 50%; pointer-events: none; z-index: 0;
  background: radial-gradient(circle, rgba(62, 232, 255, .10), transparent 65%);
  transform: translate(-50%, -50%); transition: opacity .3s; left: -999px; top: -999px;
}
.grad { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; background-size: 200% auto; animation: shine 6s linear infinite; }
@keyframes shine { to { background-position: 200% center; } }
.mono { font-family: var(--mono); }
.wrap { width: min(1280px, 92vw); margin: 0 auto; position: relative; }
section { position: relative; padding: 110px 0; }
.sec-head { text-align: center; margin-bottom: 56px; }
.sec-head .eyebrow { font-family: var(--mono); font-size: 13px; letter-spacing: .3em; color: var(--cyan); text-transform: uppercase; }
.sec-head h2 { font-size: clamp(28px, 3.6vw, 44px); font-weight: 800; letter-spacing: .02em; margin: 10px 0 12px; }
.sec-head p { color: var(--muted); max-width: 680px; margin: 0 auto; }

/* 导航 */
.nav { position: fixed; top: 0; left: 0; right: 0; z-index: 50; transition: background .35s, border-color .35s, backdrop-filter .35s; border-bottom: 1px solid transparent; }
.nav.scrolled { background: rgba(4, 9, 20, .72); backdrop-filter: blur(16px) saturate(140%); border-color: var(--line); }
.nav .wrap { display: flex; align-items: center; height: 72px; gap: 32px; }
.logo { display: flex; align-items: center; gap: 12px; font-weight: 800; font-size: 19px; letter-spacing: .06em; }
.logo svg { width: 36px; height: 36px; filter: drop-shadow(0 0 10px rgba(62, 232, 255, .6)); }
.logo small { display: block; font-family: var(--mono); font-size: 10px; letter-spacing: .25em; color: var(--muted); font-weight: 400; line-height: 1; }
.nav ul { display: flex; gap: 6px; list-style: none; margin-left: auto; }
.nav ul a { padding: 8px 16px; border-radius: 99px; color: var(--muted); font-size: 15px; transition: .25s; position: relative; }
.nav ul a:hover, .nav ul a.active { color: var(--text); background: rgba(62, 232, 255, .08); }
.nav ul a.active::after { content: ""; position: absolute; left: 50%; bottom: 2px; width: 16px; height: 2px; margin-left: -8px; background: var(--cyan); border-radius: 2px; box-shadow: 0 0 8px var(--cyan); }
.menu-btn { display: none; background: none; border: 0; font-size: 26px; cursor: pointer; }

/* 按钮 */
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 12px 26px; border-radius: 99px; border: 1px solid var(--line2); background: rgba(62, 232, 255, .06); cursor: pointer; transition: .25s; font-weight: 600; white-space: nowrap; position: relative; overflow: hidden; }
.btn:hover { border-color: var(--cyan); box-shadow: 0 0 24px rgba(62, 232, 255, .25); transform: translateY(-2px); }
.btn.primary { background: var(--grad); color: #04121f; border: 0; background-size: 200% auto; }
.btn.primary:hover { background-position: right center; box-shadow: 0 10px 34px rgba(62, 232, 255, .4); }
.btn.sm { padding: 7px 16px; font-size: 14px; }
.btn .ripple { position: absolute; border-radius: 50%; background: rgba(255, 255, 255, .45); transform: scale(0); animation: ripple .6s ease-out; pointer-events: none; }
@keyframes ripple { to { transform: scale(4); opacity: 0; } }

/* 滚动出现 */
.reveal { opacity: 0; transform: translateY(40px); transition: opacity .9s cubic-bezier(.2, .7, .2, 1), transform .9s cubic-bezier(.2, .7, .2, 1); }
.reveal.in { opacity: 1; transform: none; }
.reveal.d1 { transition-delay: .1s; } .reveal.d2 { transition-delay: .2s; } .reveal.d3 { transition-delay: .3s; } .reveal.d4 { transition-delay: .4s; }

/* 加载动画 */
#loader { position: fixed; inset: 0; z-index: 100; background: var(--bg); display: grid; place-items: center; transition: opacity .7s, visibility .7s; }
#loader.done { opacity: 0; visibility: hidden; }
.loader-dna { display: flex; gap: 7px; height: 70px; align-items: center; }
.loader-dna i { width: 8px; height: 8px; border-radius: 50%; background: var(--cyan); box-shadow: 0 0 12px var(--cyan); animation: dna 1.4s ease-in-out infinite; }
.loader-dna i:nth-child(even) { background: var(--violet); box-shadow: 0 0 12px var(--violet); animation-direction: reverse; }
.loader-dna i:nth-child(1) { animation-delay: -.0s } .loader-dna i:nth-child(2) { animation-delay: -.15s } .loader-dna i:nth-child(3) { animation-delay: -.3s }
.loader-dna i:nth-child(4) { animation-delay: -.45s } .loader-dna i:nth-child(5) { animation-delay: -.6s } .loader-dna i:nth-child(6) { animation-delay: -.75s }
.loader-dna i:nth-child(7) { animation-delay: -.9s } .loader-dna i:nth-child(8) { animation-delay: -1.05s } .loader-dna i:nth-child(9) { animation-delay: -1.2s }
@keyframes dna { 0%, 100% { transform: translateY(-26px) scale(.7); } 50% { transform: translateY(26px) scale(1.2); } }
.loader-txt { margin-top: 22px; font-family: var(--mono); letter-spacing: .4em; color: var(--muted); font-size: 12px; text-align: center; }

#toast { position: fixed; left: 50%; bottom: 40px; transform: translate(-50%, 30px); opacity: 0; z-index: 90; padding: 12px 24px; border-radius: 99px; background: rgba(14, 28, 54, .92); border: 1px solid var(--line2); backdrop-filter: blur(10px); transition: .35s; pointer-events: none; }
#toast.show { opacity: 1; transform: translate(-50%, 0); }

footer { border-top: 1px solid var(--line); padding: 50px 0 40px; color: var(--muted); font-size: 14px; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 24px; justify-content: space-between; align-items: center; }
footer .note { color: var(--dim); font-size: 13px; }