/* ============================================================
   数位律动 · DIGIT RHYME — 设计系统
   赛博 · 神经网络 · HUD 控制台
   ============================================================ */
:root{
  --bg:#04060f;
  --bg-1:#070b1a;
  --bg-2:#0c1226;
  --bg-glass:rgba(10,16,36,0.55);
  --cyan:#00e5ff;
  --cyan-dim:#0891b2;
  --purple:#b14aed;
  --magenta:#ff2d92;
  --green:#4ade80;
  --amber:#fbbf24;
  --text:#e6edf6;
  --text-2:#9fb0c4;
  --text-dim:#5a6b82;
  --line:rgba(0,229,255,.14);
  --line-2:rgba(177,74,237,.18);
  --grid:rgba(0,229,255,.045);
  --font-zh:"Noto Sans SC",system-ui,sans-serif;
  --font-en:"Orbitron",sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,monospace;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  font-family:var(--font-zh);
  background:var(--bg);
  color:var(--text);
  line-height:1.6;
  overflow-x:hidden;
  min-height:100vh;
  -webkit-font-smoothing:antialiased;
}

/* ========== 全局背景 ========== */
.bg-layer{
  position:fixed;inset:0;z-index:-2;pointer-events:none;
  background:
    radial-gradient(ellipse 80% 60% at 20% 10%, rgba(0,229,255,.08), transparent 60%),
    radial-gradient(ellipse 70% 50% at 85% 30%, rgba(177,74,237,.10), transparent 60%),
    radial-gradient(ellipse 100% 70% at 50% 100%, rgba(74,222,128,.05), transparent 60%),
    var(--bg);
}
.bg-grid{
  position:fixed;inset:0;z-index:-1;pointer-events:none;
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size:60px 60px;
  mask-image:radial-gradient(ellipse at center, black 30%, transparent 80%);
}
.bg-scan::after{
  content:"";position:fixed;inset:0;z-index:-1;pointer-events:none;
  background:repeating-linear-gradient(180deg,transparent 0,transparent 3px,rgba(0,229,255,.012) 3px,rgba(0,229,255,.012) 4px);
}
.noise{
  position:fixed;inset:0;z-index:-1;pointer-events:none;opacity:.4;
  background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='200' height='200'><filter id='n'><feTurbulence baseFrequency='0.9' numOctaves='2'/></filter><rect width='100%' height='100%' filter='url(%23n)' opacity='0.35'/></svg>");
  mix-blend-mode:overlay;
}

/* ========== HUD 状态条 ========== */
.hud-top{
  position:fixed;top:0;left:0;right:0;z-index:100;
  display:flex;justify-content:space-between;align-items:center;
  padding:8px 24px;
  font-family:var(--font-mono);font-size:11px;
  color:var(--text-dim);
  background:linear-gradient(180deg, rgba(4,6,15,.95), rgba(4,6,15,.7));
  border-bottom:1px solid var(--line);
  backdrop-filter:blur(10px);
}
.hud-top .left, .hud-top .right{display:flex;gap:18px;align-items:center}
.hud-top .dot{
  display:inline-block;width:6px;height:6px;border-radius:50%;
  background:var(--green);box-shadow:0 0 8px var(--green);
  margin-right:6px;animation:pulse 2s ease-in-out infinite;
}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:.4}}

/* ========== 主导航 ========== */
.nav{
  position:fixed;top:32px;left:0;right:0;z-index:99;
  display:flex;justify-content:space-between;align-items:center;
  padding:18px 40px;
  background:rgba(4,6,15,.6);
  border-bottom:1px solid var(--line);
  backdrop-filter:blur(20px);
}
.logo{display:flex;align-items:center;gap:12px;text-decoration:none;color:var(--text)}
.logo-mark{
  width:36px;height:36px;
  border:1px solid var(--cyan);
  position:relative;display:flex;align-items:center;justify-content:center;
  background:linear-gradient(135deg, rgba(0,229,255,.08), rgba(177,74,237,.08));
}
.logo-mark::before,.logo-mark::after{content:"";position:absolute;background:var(--cyan)}
.logo-mark::before{top:-1px;left:-1px;width:8px;height:1px}
.logo-mark::after{top:-1px;left:-1px;width:1px;height:8px}
.logo-mark span{font-family:var(--font-en);font-weight:900;font-size:14px;color:var(--cyan);letter-spacing:1px}
.logo-text{display:flex;flex-direction:column;line-height:1.1}
.logo-text .zh{font-weight:700;font-size:15px;letter-spacing:2px}
.logo-text .en{font-family:var(--font-en);font-size:9px;letter-spacing:3px;color:var(--text-dim)}

.nav-links{display:flex;gap:6px;list-style:none}
.nav-links a{
  display:block;padding:8px 16px;
  color:var(--text-2);text-decoration:none;
  font-size:13px;font-weight:500;position:relative;transition:color .2s;
  font-family:var(--font-mono);text-transform:uppercase;letter-spacing:1px;
}
.nav-links a::before{
  content:"";position:absolute;left:50%;bottom:0;
  width:0;height:1px;background:var(--cyan);
  transition:all .25s ease;transform:translateX(-50%);
}
.nav-links a:hover,.nav-links a.active{color:var(--cyan)}
.nav-links a:hover::before,.nav-links a.active::before{width:60%;box-shadow:0 0 6px var(--cyan)}

.nav-cta{
  padding:9px 18px;background:transparent;border:1px solid var(--cyan);
  color:var(--cyan);font-family:var(--font-mono);font-size:12px;letter-spacing:1px;
  text-transform:uppercase;text-decoration:none;position:relative;cursor:pointer;transition:all .2s;
}
.nav-cta::before{
  content:"";position:absolute;inset:0;background:var(--cyan);
  transform:scaleY(0);transform-origin:bottom;transition:transform .2s ease;z-index:-1;
}
.nav-cta:hover{color:var(--bg)}
.nav-cta:hover::before{transform:scaleY(1)}

/* 移动菜单 */
.nav-toggle{display:none;background:none;border:1px solid var(--line);color:var(--cyan);width:38px;height:38px;cursor:pointer;align-items:center;justify-content:center}
.nav-toggle svg{width:18px;height:18px}

/* ========== 通用容器 ========== */
.container{max-width:1320px;margin:0 auto;padding:0 40px;position:relative}

/* ========== 按钮 ========== */
.btn{
  display:inline-flex;align-items:center;gap:12px;
  padding:14px 28px;font-family:var(--font-mono);font-size:13px;font-weight:500;
  text-transform:uppercase;letter-spacing:2px;
  text-decoration:none;cursor:pointer;position:relative;transition:all .25s;border:none;
}
.btn-primary{background:var(--cyan);color:var(--bg)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 0 30px rgba(0,229,255,.5), 0 0 0 1px var(--cyan)}
.btn-primary svg{transition:transform .25s}
.btn-primary:hover svg{transform:translateX(4px)}
.btn-ghost{background:transparent;color:var(--text);border:1px solid var(--line)}
.btn-ghost:hover{border-color:var(--cyan);color:var(--cyan)}
.btn::before,.btn::after{content:"";position:absolute;width:8px;height:8px;border:1px solid currentColor}
.btn::before{top:-1px;left:-1px;border-right:0;border-bottom:0}
.btn::after{bottom:-1px;right:-1px;border-left:0;border-top:0}

/* ========== 边角装饰 ========== */
.corner{position:fixed;width:24px;height:24px;z-index:50;pointer-events:none;color:var(--cyan);opacity:.5}
.corner.tl{top:46px;left:8px;border-top:1px solid;border-left:1px solid}
.corner.tr{top:46px;right:8px;border-top:1px solid;border-right:1px solid}
.corner.bl{bottom:8px;left:8px;border-bottom:1px solid;border-left:1px solid}
.corner.br{bottom:8px;right:8px;border-bottom:1px solid;border-right:1px solid}

/* ========== 区段通用 ========== */
section.block{padding:120px 0;position:relative}
.section-head{margin-bottom:64px;display:flex;justify-content:space-between;align-items:end;flex-wrap:wrap;gap:24px}
.section-tag{
  font-family:var(--font-mono);font-size:11px;letter-spacing:3px;
  color:var(--cyan);text-transform:uppercase;
  display:flex;align-items:center;gap:10px;margin-bottom:14px;
}
.section-tag::before{content:"";width:24px;height:1px;background:var(--cyan);box-shadow:0 0 6px var(--cyan)}
.section-title{font-size:clamp(1.8rem,3.6vw,3rem);font-weight:800;letter-spacing:-.5px;line-height:1.15;max-width:780px}
.section-title em{font-style:normal;color:var(--cyan)}
.section-sub{color:var(--text-2);max-width:520px;font-size:.95rem;line-height:1.8}

/* ========== 子页面 Hero（紧凑型）========== */
.page-hero{
  padding-top:160px;padding-bottom:80px;position:relative;
  border-bottom:1px solid var(--line);overflow:hidden;
}
.breadcrumb{
  font-family:var(--font-mono);font-size:11px;color:var(--text-dim);
  letter-spacing:2px;margin-bottom:24px;text-transform:uppercase;
}
.breadcrumb a{color:var(--text-dim);text-decoration:none;transition:color .2s}
.breadcrumb a:hover{color:var(--cyan)}
.breadcrumb span{color:var(--cyan);margin:0 10px}
.page-hero h1{
  font-size:clamp(2rem,5vw,4.2rem);font-weight:900;line-height:1.05;
  letter-spacing:-1px;margin-bottom:24px;
}
.page-hero h1 .accent{
  background:linear-gradient(120deg, var(--cyan), var(--purple) 60%, var(--magenta));
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.page-hero .en{
  font-family:var(--font-en);font-size:14px;letter-spacing:6px;
  color:var(--text-dim);margin-bottom:24px;text-transform:uppercase;
}
.page-hero p.lead{max-width:720px;font-size:1.05rem;color:var(--text-2);line-height:1.85;margin-top:24px}

/* ========== 卡片网格 ========== */
.card{
  position:relative;border:1px solid var(--line);
  background:linear-gradient(180deg, var(--bg-1), var(--bg));
  padding:36px 32px;transition:all .3s;overflow:hidden;
}
.card::before{
  content:"";position:absolute;top:0;left:0;right:0;height:1px;
  background:linear-gradient(90deg, transparent, var(--cyan), transparent);
  transform:translateX(-100%);transition:transform .6s ease;
}
.card:hover::before{transform:translateX(100%)}
.card:hover{border-color:rgba(0,229,255,.3);transform:translateY(-4px)}
.card-id{font-family:var(--font-mono);font-size:10px;color:var(--text-dim);letter-spacing:2px;margin-bottom:18px}
.card-title{font-size:1.2rem;font-weight:700;margin-bottom:12px}
.card-text{color:var(--text-2);font-size:.92rem;line-height:1.75}

/* ========== Terminal 风格代码块 ========== */
.terminal{
  font-family:var(--font-mono);font-size:13px;
  background:var(--bg);border:1px solid var(--line);
  padding:24px;line-height:1.8;color:var(--text-2);
}
.terminal .line{display:flex;gap:12px}
.terminal .prompt{color:var(--cyan)}
.terminal .key{color:var(--purple)}
.terminal .val{color:var(--green)}
.terminal .cmt{color:var(--text-dim)}
.terminal .cursor{display:inline-block;width:8px;height:14px;background:var(--cyan);vertical-align:middle;animation:blink 1s steps(1) infinite}
@keyframes blink{50%{opacity:0}}

/* ========== Footer ========== */
footer{padding:60px 0 30px;border-top:1px solid var(--line);background:var(--bg);position:relative}
.footer-top{
  display:grid;grid-template-columns:1.5fr 1fr 1fr 1fr;gap:48px;
  padding-bottom:48px;border-bottom:1px solid var(--line);
}
.footer-brand p{color:var(--text-2);font-size:.9rem;line-height:1.8;margin-top:20px;max-width:340px}
.footer-col h5{font-family:var(--font-mono);font-size:11px;letter-spacing:2px;color:var(--cyan);text-transform:uppercase;margin-bottom:20px}
.footer-col ul{list-style:none;display:grid;gap:12px}
.footer-col a{color:var(--text-2);text-decoration:none;font-size:.9rem;transition:color .2s}
.footer-col a:hover{color:var(--text)}
.footer-bot{
  padding-top:30px;display:flex;justify-content:space-between;align-items:center;
  font-family:var(--font-mono);font-size:11px;color:var(--text-dim);letter-spacing:1px;
  flex-wrap:wrap;gap:12px;
}

/* ========== 通用动画 ========== */
@keyframes rise{from{transform:translateY(110%);opacity:0}to{transform:translateY(0);opacity:1}}
@keyframes fadeIn{from{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}
.reveal{opacity:0;transform:translateY(30px);transition:opacity .8s ease, transform .8s ease}
.reveal.show{opacity:1;transform:translateY(0)}

/* ========== 响应式 ========== */
@media (max-width:1024px){
  .nav-links{display:none}
  .nav-toggle{display:flex}
  .nav-links.open{
    display:flex;flex-direction:column;
    position:absolute;top:100%;left:0;right:0;
    background:var(--bg);border-bottom:1px solid var(--line);
    padding:20px;gap:0;
  }
  .nav-links.open a{padding:14px 8px;border-bottom:1px solid var(--line)}
  .footer-top{grid-template-columns:1fr 1fr;gap:32px}
}
@media (max-width:640px){
  .container,.nav{padding-left:20px;padding-right:20px}
  .nav{padding:14px 20px}
  section.block{padding:80px 0}
  .page-hero{padding-top:140px;padding-bottom:60px}
  .hud-top{font-size:10px;padding:6px 16px}
  .hud-top .left span:nth-child(n+3),.hud-top .right span:nth-child(n+2){display:none}
  .footer-top{grid-template-columns:1fr}
}