/* NETIZEN303 — share-chain 传播箭头链 hero + 卡片流. 网蓝夜 #0C1A2C × 网蓝 #4DD8FF */
:root{
  --bg:#0C1A2C;--panel:#12253C;--panel2:#183454;--text:#E6F3FF;--muted:#8FB3CC;
  --accent:#4DD8FF;--accent-2:#E0F7FF;--ink:#071320;--line:rgba(77,216,255,.32);
  --glow:0 0 12px rgba(77,216,255,.4),0 0 26px rgba(77,216,255,.2);
  --grad-panel:linear-gradient(150deg,#183454 0%,#0C1A2C 100%);
  --font-h:'Russo One',sans-serif;--font-b:'Titillium Web',sans-serif;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{background:var(--bg);color:var(--text);font-family:var(--font-b);line-height:1.7;font-size:16px}
img,svg{max-width:100%;vertical-align:middle}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
.container{width:100%;max-width:1160px;margin:0 auto;padding:0 16px}
.container.narrow{max-width:840px}
.center{text-align:center}
.site-header{position:sticky;top:0;z-index:50;background:rgba(12,26,44,.92);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.head-in{display:flex;align-items:center;gap:14px;min-height:60px}
.brand{display:inline-flex;align-items:center;gap:8px;font-family:var(--font-h);font-weight:400;font-size:1.1rem;color:var(--text);white-space:nowrap;letter-spacing:.03em}
.brand:hover{text-decoration:none}
.nav-main{display:none;margin-left:auto;gap:18px}
.nav-main a{color:var(--muted);font-weight:600;font-size:.95rem}
.nav-main a:hover{color:var(--accent);text-decoration:none}
.head-cta{display:flex;gap:8px;margin-left:auto}
.nav-main+.head-cta{margin-left:0}
.btn{display:inline-block;padding:10px 20px;border-radius:10px;font-family:var(--font-b);font-weight:700;font-size:.9rem;cursor:pointer;border:1px solid transparent;transition:transform .15s}
.btn:hover{text-decoration:none;transform:translateY(-1px)}
.btn-primary{background:linear-gradient(135deg,#4DD8FF,#1E9FD8);color:var(--ink);box-shadow:var(--glow)}
.btn-secondary{background:transparent;color:var(--accent);border-color:rgba(77,216,255,.55)}
.btn-block{display:block;width:100%;text-align:center}
.pulse{animation:pulse-glow 2s infinite}
@keyframes pulse-glow{0%,100%{box-shadow:0 0 8px rgba(77,216,255,.4)}50%{box-shadow:0 0 22px rgba(77,216,255,.8)}}
.nav-switch{display:none}
.burger{display:flex;flex-direction:column;gap:4px;cursor:pointer;padding:6px;margin-left:4px}
.burger span{width:22px;height:2px;background:var(--accent);border-radius:2px}
.m-nav{display:none;background:var(--panel);border-bottom:1px solid var(--line)}
.m-nav-group{padding:10px 16px}
.m-nav-group h3{font-size:.8rem;text-transform:uppercase;letter-spacing:.08em;color:var(--accent);margin-bottom:6px;font-weight:700}
.m-nav-group a{display:block;padding:6px 0;color:var(--text)}
.nav-switch:checked~.m-nav{display:block}
/* share-chain hero：节点+连线+箭头扩散 */
.chain-hero{padding:44px 0 8px;background:
  radial-gradient(58% 64% at 50% 0%,rgba(77,216,255,.13) 0%,rgba(12,26,44,0) 70%),
  repeating-linear-gradient(90deg,rgba(77,216,255,.05) 0 1px,transparent 1px 64px),
  repeating-linear-gradient(0deg,rgba(77,216,255,.04) 0 1px,transparent 1px 64px)}
.chain-head{text-align:center}
.chain-head h1{font-family:var(--font-h);font-weight:400;font-size:clamp(2.1rem,6.5vw,3.6rem);letter-spacing:.04em;text-shadow:0 2px 0 #0A4A73,0 0 26px rgba(77,216,255,.45)}
.hero-sub{max-width:640px;margin:12px auto 20px;color:var(--muted)}
.hero-cta{display:flex;gap:12px;justify-content:center;flex-wrap:wrap}
.chain-stage{display:flex;flex-direction:column;align-items:center;max-width:640px;margin:28px auto 0}
.chain-node{display:flex;flex-direction:column;align-items:center;gap:2px;width:min(320px,88%);background:var(--grad-panel);border:1px solid var(--line);border-radius:14px;padding:12px 14px;text-align:center;box-shadow:0 4px 18px rgba(4,10,20,.5);animation:node-beacon 2.8s ease-in-out infinite}
.chain-node:nth-of-type(3){animation-delay:.45s}
.chain-node:nth-of-type(5){animation-delay:.9s}
.chain-node:nth-of-type(7){animation-delay:1.35s}
.chain-node-end{border-color:rgba(77,216,255,.6)}
.chain-num{font-family:var(--font-h);font-size:.72rem;letter-spacing:.2em;color:var(--accent)}
.chain-label{font-family:var(--font-h);font-size:1.05rem;color:var(--accent-2);letter-spacing:.06em}
.chain-cap{font-size:.78rem;color:var(--muted)}
.chain-seg{position:relative;width:2px;height:36px;background:linear-gradient(180deg,rgba(77,216,255,.15),rgba(77,216,255,.65))}
.chain-seg::before{content:"";position:absolute;left:50%;margin-left:-3px;top:0;width:6px;height:6px;border-radius:50%;background:var(--accent-2);box-shadow:0 0 10px rgba(77,216,255,.9);animation:seg-run-v 1.6s linear infinite}
.chain-seg::after{content:"";position:absolute;bottom:-2px;left:50%;margin-left:-5px;border-left:5px solid transparent;border-right:5px solid transparent;border-top:7px solid var(--accent)}
@keyframes seg-run-v{0%{top:-3px;opacity:0}15%{opacity:1}85%{opacity:1}100%{top:calc(100% - 3px);opacity:0}}
@keyframes seg-run-h{0%{left:-3px;opacity:0}15%{opacity:1}85%{opacity:1}100%{left:calc(100% - 3px);opacity:0}}
@keyframes node-beacon{0%,100%{border-color:var(--line);box-shadow:0 4px 18px rgba(4,10,20,.5)}50%{border-color:rgba(77,216,255,.8);box-shadow:0 0 18px rgba(77,216,255,.35)}}
.chain-chips{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;margin:18px 0 4px}
.chip{font-size:.78rem;letter-spacing:.06em;color:var(--accent);border:1px solid var(--line);border-radius:99px;padding:3px 14px;background:rgba(12,26,44,.6)}
.chip-soft{color:var(--accent-2);border-color:rgba(224,247,255,.35)}
.section{padding:38px 0}
.section-alt{background:rgba(18,37,60,.55)}
.sec-title{font-family:var(--font-h);font-weight:400;font-size:1.5rem;margin-bottom:18px;text-align:center}
.sec-sub{color:var(--muted);text-align:center;max-width:660px;margin:-8px auto 18px;font-size:.92rem}
/* 卡片栅格（快捷/教育集群/优势/精选共用骨架） */
.quick-grid,.viral-grid,.plus-grid,.pick-grid{display:grid;gap:16px;grid-template-columns:1fr;margin-bottom:8px}
.quick-card,.viral-card,.plus-card,.pick-card{display:block;background:var(--grad-panel);border:1px solid var(--line);border-radius:14px;padding:18px;color:var(--text);transition:border-color .15s,box-shadow .15s}
a.quick-card:hover,a.viral-card:hover,a.pick-card:hover{border-color:var(--accent);box-shadow:var(--glow);text-decoration:none}
.quick-card h3,.viral-card h3,.plus-card h3,.pick-card h3{font-size:1.05rem;margin-bottom:6px;color:var(--accent)}
.quick-card p,.viral-card p,.plus-card p,.pick-card p{color:var(--muted);font-size:.92rem}
.qc-icon{font-size:1.5rem;display:block;margin-bottom:8px}
/* Rantai Viral 传播链解剖卡 */
.rantai-grid{display:grid;gap:26px;grid-template-columns:1fr;margin:18px 0 16px}
.rantai-card{position:relative;background:var(--grad-panel);border:1px solid var(--line);border-radius:14px;padding:18px}
.rantai-card:not(:last-child)::after{content:"";position:absolute;left:50%;bottom:-19px;margin-left:-6px;border-left:6px solid transparent;border-right:6px solid transparent;border-top:9px solid rgba(77,216,255,.75)}
.rantai-icon{display:flex;align-items:center;justify-content:center;width:52px;height:52px;border-radius:12px;background:rgba(12,26,44,.72);border:1px solid var(--line);margin-bottom:10px}
.rantai-icon svg{width:30px;height:40px}
.rantai-step{position:absolute;top:12px;right:14px;font-family:var(--font-h);font-size:1.6rem;color:rgba(77,216,255,.28)}
.rantai-name{font-family:var(--font-h);font-weight:400;font-size:1.12rem;color:var(--accent)}
.rantai-role{font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);margin:2px 0 8px;font-weight:700}
.rantai-card>p:not(.rantai-role):not(.rantai-q){color:var(--muted);font-size:.92rem;margin-bottom:10px}
.rantai-q{border-left:3px solid var(--accent);padding:8px 12px;background:rgba(4,12,22,.55);border-radius:0 10px 10px 0;font-size:.9rem;color:var(--muted)}
.rantai-q strong{color:var(--accent)}
.trust-zone p{max-width:640px;margin:10px auto;color:var(--muted)}
.trust-zone .pill-18{margin:6px 0 12px}
.prose .note{color:var(--muted);font-size:.9rem}
.page-head{padding-top:22px}
.page-head h1,.prose h1{font-family:var(--font-h);font-weight:400;font-size:clamp(1.5rem,4.5vw,2.2rem);line-height:1.3}
.prose h2{font-family:var(--font-h);font-weight:400;font-size:1.35rem;margin:26px 0 10px;line-height:1.35}
.prose h3{font-size:1.08rem;font-weight:700;margin:20px 0 8px;color:var(--accent)}
.prose p{margin:0 0 14px}
.prose ul,.prose ol{margin:0 0 14px 22px}
.prose li{margin-bottom:6px}
.steps li{margin-bottom:10px}
.steps li strong{color:var(--accent)}
.field-form{display:grid;gap:8px;max-width:360px;margin:12px 0}
.field-form label{font-size:.85rem;color:var(--muted)}
.field-form input{background:#0A1626;border:1px solid var(--line);border-radius:8px;padding:10px 12px;color:var(--text);font-family:var(--font-b)}
.field-form input:focus{outline:none;border-color:var(--accent)}
.form-card{margin:14px 0}
.acc{display:grid;gap:10px;margin:14px 0}
.acc-item{background:var(--grad-panel);border:1px solid var(--line);border-radius:10px;overflow:hidden}
.acc-item summary{cursor:pointer;padding:13px 16px;font-weight:700;list-style:none;position:relative;color:var(--text)}
.acc-item summary::-webkit-details-marker{display:none}
.acc-item summary::after{content:"+";position:absolute;right:16px;color:var(--accent)}
.acc-item[open] summary::after{content:"−"}
.acc-item p{padding:0 16px 14px;color:var(--muted);font-size:.95rem}
.err-wrap{padding:70px 16px}
.err-code{font-family:var(--font-h);font-size:5rem;color:var(--accent);text-shadow:var(--glow)}
.err-wrap .btn{margin:18px 0}
.crumbs{padding:12px 0 0;font-size:.82rem;color:var(--muted)}
.crumbs ol{list-style:none;display:flex;flex-wrap:wrap;gap:6px}
.crumbs li+li::before{content:"›";margin-right:6px;color:var(--accent)}
.site-footer{background:var(--panel);border-top:1px solid var(--line);padding:36px 0 92px;margin-top:30px}
.foot-grid{display:grid;gap:24px;grid-template-columns:1fr}
.foot-brand p{color:var(--muted);font-size:.9rem;margin:10px 0}
.foot-col h3{font-size:.85rem;text-transform:uppercase;letter-spacing:.08em;color:var(--accent);margin-bottom:8px;font-weight:700}
.foot-col a{display:block;color:var(--muted);padding:3px 0;font-size:.92rem}
.foot-col a:hover{color:var(--accent);text-decoration:none}
.pill-18{display:inline-block;border:1px solid var(--accent);color:var(--accent);border-radius:999px;padding:2px 12px;font-weight:700;font-size:.85rem}
.foot-note{margin-top:24px;padding-top:16px;border-top:1px solid rgba(77,216,255,.22);color:var(--muted);font-size:.85rem}
.float-cta{position:fixed;left:0;right:0;bottom:0;z-index:60;padding:10px 16px calc(10px + env(safe-area-inset-bottom));background:rgba(12,26,44,.92);backdrop-filter:blur(8px);border-top:1px solid rgba(77,216,255,.4)}
@media (max-width:767px){
  .head-in{gap:8px}
  .brand{font-size:.98rem}
  .brand .logo-mark{width:26px;height:26px}
  .head-cta{gap:6px}
  .head-cta .btn{padding:8px 13px;font-size:.85rem}
  .burger{padding:5px}
}
@media (min-width:768px){
  .quick-grid{grid-template-columns:repeat(2,1fr)}
  .viral-grid,.plus-grid,.pick-grid{grid-template-columns:repeat(2,1fr)}
  .rantai-grid{grid-template-columns:repeat(4,1fr);gap:30px}
  .rantai-card:not(:last-child)::after{left:auto;bottom:auto;right:-23px;top:50%;margin-left:0;margin-top:-6px;border-top:6px solid transparent;border-bottom:6px solid transparent;border-left:9px solid rgba(77,216,255,.75);border-right:none}
  .foot-grid{grid-template-columns:2fr 1fr 1.4fr 1fr}
  .nav-main{display:flex}
  .head-cta{margin-left:0}
  .burger{display:none}
  .m-nav{display:none!important}
  .chain-stage{flex-direction:row;justify-content:center;align-items:stretch;max-width:980px;gap:0}
  .chain-node{width:186px;padding:16px 12px}
  .chain-seg{width:46px;height:2px;align-self:center;background:linear-gradient(90deg,rgba(77,216,255,.15),rgba(77,216,255,.65))}
  .chain-seg::before{left:0;top:50%;margin-left:0;margin-top:-3px;animation-name:seg-run-h}
  .chain-seg::after{bottom:auto;left:auto;right:-2px;top:50%;margin-left:0;margin-top:-5px;border-left:7px solid var(--accent);border-top:5px solid transparent;border-bottom:5px solid transparent;border-right:none}
  .float-cta{left:auto;right:18px;bottom:18px;border-radius:12px;border:1px solid rgba(77,216,255,.5)}
  .float-cta .btn-block{width:auto}
}
@media (min-width:1024px){
  .quick-grid{grid-template-columns:repeat(4,1fr)}
  .viral-grid,.plus-grid{grid-template-columns:repeat(3,1fr)}
  .form-grid{grid-template-columns:repeat(3,1fr)}
}
@media (prefers-reduced-motion:reduce){.pulse,.chain-node,.chain-seg::before{animation:none}}

/* ===== Float CTA Jackpot v2 (2026-09-13): 底部居中 + 闪烁 ===== */
.float-cta{left:50%;right:auto;transform:translateX(-50%);width:100%;max-width:600px;margin:0;display:block}
.float-inner{display:flex;align-items:center;justify-content:center;gap:12px;flex-wrap:wrap}
.jackpot-tag{display:inline-flex;align-items:center;gap:6px;font-weight:800;font-size:1rem;letter-spacing:.02em;color:#FFE066;text-shadow:0 0 10px rgba(255,224,102,.6)}
.jackpot-blink{animation:jackpot-blink 1.1s ease-in-out infinite}
@keyframes jackpot-blink{0%,100%{opacity:1;text-shadow:0 0 10px rgba(255,224,102,.85),0 0 22px rgba(255,224,102,.45)}50%{opacity:.5;text-shadow:0 0 4px rgba(255,224,102,.3)}}
.masuk-btn{position:relative;overflow:hidden;white-space:nowrap;flex:0 0 auto;font-weight:800;letter-spacing:.02em;animation:masuk-glow 1.4s ease-in-out infinite}
.masuk-btn::after{content:"";position:absolute;top:0;left:-80%;width:55%;height:100%;background:linear-gradient(105deg,rgba(255,255,255,0) 0%,rgba(255,255,255,.55) 50%,rgba(255,255,255,0) 100%);transform:skewX(-20deg);animation:masuk-shine 1.8s linear infinite}
@keyframes masuk-shine{0%{left:-80%}55%,100%{left:130%}}
@keyframes masuk-glow{0%,100%{box-shadow:0 0 8px rgba(255,215,80,.55)}50%{box-shadow:0 0 24px rgba(255,215,80,.95),0 0 40px rgba(255,180,40,.5)}}
.jp-spark{display:inline-block;animation:spark-twinkle 1s ease-in-out infinite}
@keyframes spark-twinkle{0%,100%{transform:scale(1);opacity:1}50%{transform:scale(.55) rotate(18deg);opacity:.45}}
@media (prefers-reduced-motion:reduce){.jackpot-blink,.masuk-btn,.masuk-btn::after,.jp-spark{animation:none}}