/* ===== 所想即成 · tech nav ===== */
:root{
  --bg:#05060c;
  --fg:#e8ecf8;
  --muted:#8b93ad;
  --cyan:#22d3ee;
  --violet:#8b5cf6;
  --pink:#f472b6;
  --stroke:rgba(255,255,255,.09);
  --glass-hi:rgba(255,255,255,.075);
  --glass-lo:rgba(255,255,255,.025);
  --rail-w:212px;
  --cw:268px;
  --ch:132px;
  --ease:cubic-bezier(.16,1,.3,1);
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  background:var(--bg);
  color:var(--fg);
  font-family:"HarmonyOS Sans SC","PingFang SC","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
::selection{background:rgba(34,211,238,.28);color:#fff}
::-webkit-scrollbar{width:10px;height:10px}
::-webkit-scrollbar-thumb{background:rgba(255,255,255,.12);border-radius:99px;border:3px solid var(--bg)}
::-webkit-scrollbar-track{background:transparent}

/* ---------- 背景：鼠标跟随时变色 ---------- */
.aurora{position:fixed;inset:0;z-index:-1;pointer-events:none;overflow:hidden;background:var(--bg)}
.aurora__glow{
  position:absolute;inset:-25%;
  background:
    radial-gradient(620px 460px at var(--mx,50%) var(--my,32%), rgba(34,211,238,.20), transparent 62%),
    radial-gradient(760px 560px at calc(100% - var(--mx,50%)) calc(100% - var(--my,32%)), rgba(139,92,246,.24), transparent 64%),
    radial-gradient(900px 660px at 50% 118%, rgba(244,114,182,.10), transparent 62%);
  filter:blur(14px) hue-rotate(var(--hue,0deg));
  transition:filter .35s linear;
}
.aurora__mesh{
  position:absolute;inset:0;
  background-image:
    linear-gradient(rgba(255,255,255,.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.055) 1px, transparent 1px);
  background-size:56px 56px;
  -webkit-mask-image:radial-gradient(560px 480px at var(--mx,50%) var(--my,35%), #000 0%, rgba(0,0,0,.35) 46%, transparent 76%);
  mask-image:radial-gradient(560px 480px at var(--mx,50%) var(--my,35%), #000 0%, rgba(0,0,0,.35) 46%, transparent 76%);
  opacity:.75;
}
.aurora__grain{
  position:absolute;inset:0;opacity:.05;mix-blend-mode:overlay;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='2'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)'/%3E%3C/svg%3E");
}
.aurora::after{
  content:"";position:absolute;inset:0;
  background:radial-gradient(120% 90% at 50% 0%, transparent 40%, rgba(5,6,12,.85) 100%);
}

/* ---------- 顶栏 ---------- */
.hud{
  position:fixed;top:0;left:0;right:0;z-index:20;
  height:76px;display:flex;align-items:center;justify-content:space-between;gap:24px;
  padding:0 40px 0 28px;
  background:linear-gradient(180deg, rgba(5,6,12,.86), rgba(5,6,12,.55));
  backdrop-filter:blur(16px) saturate(140%);
  -webkit-backdrop-filter:blur(16px) saturate(140%);
  border-bottom:1px solid var(--stroke);
}
.brand{display:flex;align-items:center;gap:12px;min-width:0}
.brand__mark{width:36px;height:36px;display:block;flex:none;filter:drop-shadow(0 0 12px rgba(34,211,238,.35))}
.brand__mark svg{width:100%;height:100%}
.brand__text{display:flex;flex-direction:column;line-height:1.25;min-width:0}
.brand__text strong{
  font-size:16px;font-weight:650;letter-spacing:.12em;
  background:linear-gradient(100deg,#eaf6ff 10%,#7fe3f5 55%,#b79bff 95%);
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.brand__text em{font-style:normal;font-size:10.5px;letter-spacing:.16em;color:var(--muted)}

.search{
  display:flex;align-items:center;gap:10px;
  width:min(440px,46vw);height:40px;padding:0 8px 0 14px;
  border:1px solid var(--stroke);border-radius:999px;
  background:rgba(255,255,255,.035);
  transition:border-color .3s,box-shadow .3s,background .3s;
}
.search:focus-within{border-color:rgba(34,211,238,.45);box-shadow:0 0 0 4px rgba(34,211,238,.08);background:rgba(255,255,255,.06)}
.search svg{width:15px;height:15px;flex:none;fill:none;stroke:var(--muted);stroke-width:1.8;stroke-linecap:round}
.search input{flex:1;min-width:0;border:0;outline:0;background:transparent;color:var(--fg);font-size:13px;font-family:inherit}
.search input::placeholder{color:#626b85}
.search kbd{font:10px/1 ui-monospace,monospace;color:#6f7894;border:1px solid var(--stroke);border-radius:6px;padding:4px 6px;letter-spacing:.08em}

/* ---------- 左侧分类导航 ---------- */
.rails{
  position:fixed;top:76px;left:0;bottom:0;width:var(--rail-w);z-index:15;
  padding:22px 14px;
  display:flex;flex-direction:column;gap:4px;
  border-right:1px solid var(--stroke);
  background:linear-gradient(180deg, rgba(6,7,14,.55), rgba(6,7,14,.25));
  backdrop-filter:blur(10px);
  overflow-y:auto;
}
.rail{
  display:flex;align-items:center;gap:11px;
  padding:10px 12px;border-radius:11px;border:1px solid transparent;
  font-size:13px;color:#98a2bd;
  transition:background .25s,color .25s,border-color .25s,transform .25s;
}
.rail:hover{background:rgba(255,255,255,.05);color:#fff;transform:translateX(2px)}
.rail.active{
  color:#fff;border-color:rgba(34,211,238,.26);
  background:linear-gradient(90deg, rgba(34,211,238,.14), rgba(139,92,246,.08) 70%, transparent);
  box-shadow:inset 0 0 24px rgba(34,211,238,.06);
}
.rail__i{width:24px;height:24px;flex:none;display:grid;place-items:center;font-size:15px;border-radius:7px;background:rgba(255,255,255,.05);border:1px solid rgba(255,255,255,.07)}
.rail__n{flex:1;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.rail__c{font:10px/1 ui-monospace,monospace;color:#6f7894}
.rail.active .rail__c{color:#7fe3f5}

/* ---------- 主区域 ---------- */
main{margin-left:var(--rail-w);padding:96px 46px 30px;max-width:1560px}
.hero{padding:6px 0 0}
.hero__eyebrow{
  display:flex;align-items:center;gap:8px;margin:0 0 12px;
  font:11px/1 ui-monospace,monospace;letter-spacing:.22em;color:#7fe3f5;text-transform:uppercase;
}
.pulse{width:7px;height:7px;border-radius:50%;background:var(--cyan);box-shadow:0 0 0 0 rgba(34,211,238,.6);animation:pulse 2.4s infinite}
@keyframes pulse{
  0%{box-shadow:0 0 0 0 rgba(34,211,238,.55)}
  70%{box-shadow:0 0 0 9px rgba(34,211,238,0)}
  100%{box-shadow:0 0 0 0 rgba(34,211,238,0)}
}
.hero__title{
  margin:0;font-size:clamp(28px,3.5vw,46px);line-height:1.14;font-weight:700;letter-spacing:.01em;
  color:#dbe6ff;
}
.hero__title span{
  background:linear-gradient(100deg,#7fe3f5 0%,#a78bfa 55%,#f472b6 100%);
  -webkit-background-clip:text;background-clip:text;color:transparent;
  filter:drop-shadow(0 0 26px rgba(139,92,246,.28));
}
.hero__sub{margin:14px 0 0;max-width:640px;font-size:13.5px;line-height:1.8;color:var(--muted)}
.hero__stats{display:flex;flex-wrap:wrap;gap:26px;margin-top:22px}
.stat{display:flex;flex-direction:column;gap:3px}
.stat b{font:600 20px/1 ui-monospace,monospace;color:#dfe9ff}
.stat span{font-size:10.5px;letter-spacing:.14em;color:#6f7894;text-transform:uppercase}

/* ---------- 分类区块 ---------- */
.cat{margin-top:44px;scroll-margin-top:100px}
.cat__head{display:flex;align-items:center;gap:12px;margin-bottom:14px}
.cat__icon{
  width:34px;height:34px;flex:none;display:grid;place-items:center;font-size:17px;border-radius:10px;
  background:linear-gradient(160deg, rgba(34,211,238,.14), rgba(139,92,246,.10));
  border:1px solid rgba(255,255,255,.10);
  box-shadow:inset 0 1px 0 rgba(255,255,255,.14);
}
.cat__title{font-size:17px;font-weight:650;letter-spacing:.02em;margin:0}
.cat__count{font:10.5px/1 ui-monospace,monospace;letter-spacing:.1em;color:#7fe3f5;padding:5px 9px;border:1px solid rgba(34,211,238,.25);border-radius:999px;background:rgba(34,211,238,.06)}
.cat__hint{margin-left:auto;font-size:11px;letter-spacing:.08em;color:#5d6680}

/* ---------- 卡片堆 ---------- */
.deck{
  position:relative;height:236px;
  border:1px solid var(--stroke);border-radius:22px;
  background:
    radial-gradient(120% 90% at 20% 0%, rgba(34,211,238,.06), transparent 55%),
    linear-gradient(165deg, rgba(255,255,255,.035), rgba(255,255,255,.012));
  overflow:hidden;
  transition:height .62s var(--ease), border-color .4s, box-shadow .4s;
}
.deck::before{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:linear-gradient(90deg, transparent, rgba(34,211,238,.5), rgba(139,92,246,.5), transparent) top/100% 1px no-repeat;
  opacity:.35;
}
.deck::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:radial-gradient(420px 220px at 50% 50%, rgba(34,211,238,.06), transparent 70%);
}
.deck.expanded{border-color:rgba(34,211,238,.22);box-shadow:0 0 0 1px rgba(34,211,238,.06), 0 30px 80px -30px rgba(34,211,238,.18)}

.deck__hint{
  position:absolute;left:50%;bottom:16px;transform:translateX(-50%);
  display:flex;align-items:center;gap:7px;
  font-size:11px;letter-spacing:.1em;color:#69728c;white-space:nowrap;
  transition:opacity .3s;
}
.deck.expanded .deck__hint{opacity:0}
.deck__hint i{width:5px;height:5px;border-radius:50%;background:#7fe3f5;box-shadow:0 0 8px #22d3ee}

/* ---------- 卡片 ---------- */
.card{
  position:absolute;left:50%;top:50%;
  width:var(--cw);height:var(--ch);
  margin-left:calc(var(--cw) / -2);margin-top:calc(var(--ch) / -2);
  transform:translate3d(var(--tx,0px),var(--ty,0px),0) rotate(var(--rot,0deg)) scale(var(--sc,1));
  transition:transform .7s var(--ease), opacity .42s ease;
  transition-delay:var(--d,0ms);
  opacity:var(--op,1);
  will-change:transform;
}
.deck:not(.expanded) .card{pointer-events:none}
.card__in{
  position:relative;height:100%;
  display:flex;gap:12px;padding:15px 16px;
  border-radius:16px;border:1px solid rgba(255,255,255,.12);
  background:linear-gradient(145deg, rgba(255,255,255,.10), rgba(255,255,255,.028) 55%, rgba(255,255,255,.05));
  backdrop-filter:blur(18px) saturate(150%);
  -webkit-backdrop-filter:blur(18px) saturate(150%);
  box-shadow:0 18px 40px -18px rgba(0,0,0,.75), inset 0 1px 0 rgba(255,255,255,.16), inset 0 -1px 0 rgba(0,0,0,.25);
  transition:transform .35s var(--ease), border-color .3s, box-shadow .35s, background .35s;
  overflow:hidden;
}
.card__in::after{
  content:"";position:absolute;inset:0;border-radius:inherit;pointer-events:none;
  background:radial-gradient(220px 160px at var(--gx,50%) var(--gy,50%), rgba(255,255,255,.16), transparent 65%);
  opacity:0;transition:opacity .3s;
}
.card:hover .card__in{
  transform:translateY(-5px);
  border-color:rgba(34,211,238,.42);
  box-shadow:0 24px 60px -20px rgba(34,211,238,.35), inset 0 1px 0 rgba(255,255,255,.22);
}
.card:hover .card__in::after{opacity:1}

.card__ico{
  width:40px;height:40px;flex:none;border-radius:11px;display:grid;place-items:center;
  background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.10);
  box-shadow:inset 0 1px 0 rgba(255,255,255,.12);
  overflow:hidden;
}
.card__ico img{width:22px;height:22px;object-fit:contain;display:block}
.card__ico span{font:600 15px/1 ui-monospace,monospace;color:#a9b4d0}
.card__body{min-width:0;display:flex;flex-direction:column;justify-content:center;gap:3px}
.card__name{font-size:13.5px;font-weight:600;color:#eaf1ff;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;letter-spacing:.01em}
.card__desc{
  margin:0;font-size:11px;line-height:1.55;color:#95a0bc;
  display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;
}
.card__tags{display:flex;gap:4px;flex-wrap:wrap;margin-top:4px}
.card__tag{font-size:9.5px;line-height:1;padding:3px 6px;border-radius:999px;color:#7fe3f5;background:rgba(34,211,238,.07);border:1px solid rgba(34,211,238,.20)}

/* 展开态卡片轻微错峰升起 */
.deck.expanded .card{opacity:1;z-index:1}

/* ---------- 页脚 ---------- */
.foot{
  margin-left:var(--rail-w);padding:46px 46px 40px;
  display:flex;align-items:center;gap:12px;flex-wrap:wrap;
  font-size:11.5px;color:#5d6680;letter-spacing:.06em;
  border-top:1px solid rgba(255,255,255,.05);
}
.foot__dot{width:4px;height:4px;border-radius:50%;background:#3c4560}

/* ---------- 窄屏 ---------- */
@media (max-width:900px){
  .hud{height:66px;padding:0 16px;gap:12px}
  .brand__text em{display:none}
  .search{width:auto;flex:1;height:38px}
  .search kbd{display:none}
  .rails{
    top:66px;left:0;right:0;bottom:auto;width:auto;height:auto;
    flex-direction:row;gap:8px;padding:10px 14px;
    overflow-x:auto;overflow-y:hidden;
    border-right:0;border-bottom:1px solid var(--stroke);
  }
  .rails::-webkit-scrollbar{display:none}
  .rail{flex:none;padding:8px 12px;font-size:12px}
  .rail__c{display:none}
  main{margin-left:0;padding:140px 18px 20px}
  .hero__stats{gap:18px}
  .cat{margin-top:38px}
  .cat__hint{display:none}
  .deck{height:auto!important;padding:14px;display:grid;gap:12px}
  .deck__hint{display:none}
  .card{
    position:relative;left:auto;top:auto;margin:0;width:100%;height:auto;
    transform:none!important;opacity:1!important;
  }
  .card__in{min-height:98px}
  .foot{margin-left:0;padding:30px 18px}
}

@media (prefers-reduced-motion:reduce){
  *{animation:none!important;transition-duration:.01ms!important}
  html{scroll-behavior:auto}
}