/* ============================================================
   码枪堂 · 三角洲行动优化助手 — 官网样式
   设计语言：白色画布 + 浅蓝分区 + 天蓝强调
   ============================================================ */
:root{
  --accent:#B8DEFF;
  --accent-hover:#9CCFFC;
  --accent-soft:#DDEFFF;
  --accent-ink:#22567D;
  --accent-line:#93C5ED;
  --ink:#20364A;
  --ink-2:#415D73;
  --ink-3:#526F85;
  --paper:#F0F8FF;
  --white:#FFFFFF;
  --line:rgba(58,104,143,.12);
  --line-dark:rgba(255,255,255,.14);
  --radius:20px;
  --shadow:0 24px 60px -24px rgba(58,104,143,.28);
  --font:"PingFang SC","Microsoft YaHei","HarmonyOS Sans SC","Source Han Sans SC",sans-serif;
  --font-num:"Bahnschrift","DIN Alternate","Arial Narrow",var(--font);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:var(--font);color:var(--ink);background:var(--paper);line-height:1.6;overflow-x:hidden;-webkit-font-smoothing:antialiased}
img,svg{display:block}
a{color:inherit;text-decoration:none}
button{font-family:inherit;border:none;background:none;cursor:pointer;color:inherit}
.wrap{width:min(1200px,92%);margin:0 auto}

/* ---------- 通用组件 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:10px;
  font-weight:700;font-size:16px;letter-spacing:.02em;
  padding:16px 34px;border-radius:999px;white-space:nowrap;
  transition:transform .2s ease,box-shadow .2s ease,background .2s ease,color .2s ease,border-color .2s ease;
}
.btn svg{width:19px;height:19px}
.btn-primary{background:var(--accent);color:var(--accent-ink);box-shadow:0 14px 30px -12px rgba(58,104,143,.22)}
.btn-primary:hover{background:var(--accent-hover);transform:translateY(-2px);box-shadow:0 20px 36px -12px rgba(58,104,143,.28)}
.btn-ghost{background:rgba(255,255,255,.78);color:var(--ink);border:1.5px solid rgba(58,104,143,.28);backdrop-filter:blur(6px)}
.btn-ghost:hover{background:var(--white);border-color:var(--ink);transform:translateY(-2px)}
.btn-ghost-dark{background:transparent;color:var(--ink-2);border:1.5px solid var(--line)}
.btn-ghost-dark:hover{border-color:var(--ink);color:var(--ink)}
.btn-sm{padding:10px 22px;font-size:14px}
.btn-xl{width:100%;padding:18px 34px;font-size:17px}
.dl-actions{display:flex;gap:12px;margin-top:24px;flex-wrap:wrap}
.dl-actions .btn{flex:1 1 200px}

.eyebrow{display:flex;align-items:center;gap:12px;font-size:14px;font-weight:600;letter-spacing:.24em;color:var(--ink-2)}
.eyebrow-line{width:30px;height:3px;background:var(--accent);border-radius:2px;flex:none}
.sec-head{max-width:640px;margin:0 auto 56px;text-align:left}
.sec-head .eyebrow{margin-bottom:18px}
.sec-head h2{font-size:clamp(30px,4vw,46px);font-weight:900;letter-spacing:.01em;line-height:1.2}
.sec-sub{margin-top:14px;color:var(--ink-3);font-size:16px}

/* 滚动进入动画 */
.reveal{opacity:0;transform:translateY(26px);transition:opacity .7s ease,transform .7s ease}
.reveal.delay-1{transition-delay:.1s}.reveal.delay-2{transition-delay:.2s}.reveal.delay-3{transition-delay:.3s}
.reveal.in{opacity:1;transform:none}
@media (prefers-reduced-motion:reduce){.reveal{opacity:1;transform:none;transition:none}}

/* ============================================================
   导航：透明 overlay，滚动后转白底
   ============================================================ */
.nav{position:fixed;inset:0 0 auto 0;z-index:100;background:transparent;border-bottom:1px solid transparent;transition:background .3s ease,box-shadow .3s ease}
.nav.scrolled,.nav.open{background:rgba(255,255,255,.96);border-bottom-color:var(--line);backdrop-filter:blur(18px);box-shadow:0 4px 24px -16px rgba(58,104,143,.25)}
.nav-inner{width:min(1600px,92%);margin:0 auto;height:80px;display:flex;align-items:center;gap:36px}
.brand{display:flex;align-items:center;gap:11px;color:var(--ink)}
.brand-mark{width:46px;height:46px;object-fit:contain;flex:none}
.brand-name{font-weight:900;font-size:19px;letter-spacing:.06em;display:flex;flex-direction:column;line-height:1.05}
.brand-name small{font-size:9px;font-weight:600;letter-spacing:.34em;color:var(--ink-3)}
.nav-links{display:flex;align-items:center;gap:0;margin-left:auto;padding:0 4px;border-radius:999px;background:rgba(255,255,255,.84);backdrop-filter:blur(16px)}
.nav-links a{position:relative;padding:10px 18px;font-size:14px;font-weight:600;color:var(--ink-2);transition:color .2s}
.nav-links a::after{content:"";position:absolute;left:0;right:0;bottom:4px;height:2px;background:var(--accent-line);transform:scaleX(0);transform-origin:left;transition:transform .2s}
.nav-links a:hover{color:var(--accent-ink)}
.nav-links a:hover::after,.nav-links a:focus-visible::after{transform:scaleX(1)}
.nav a:focus-visible,.nav-burger:focus-visible{outline:2px solid var(--accent-ink);outline-offset:5px}
.nav-cta{display:flex;align-items:center;gap:14px}
.nav-cta .btn{padding:11px 20px;border-radius:999px;font-size:14px;gap:8px;box-shadow:none}
.nav-cta .btn svg{width:16px;height:16px}
.nav-burger{display:none;flex-direction:column;gap:5px;padding:8px}
.nav-burger span{width:22px;height:2px;background:var(--ink);border-radius:2px;transition:.25s}

/* ============================================================
   Hero：100vh 全幅主视觉 · 左文右图 overlay
   ============================================================ */
.hero{position:relative;height:100svh;min-height:700px;overflow:hidden}
/* 原始画布铺满首屏，避免额外放大让右侧人物挤满画面。 */
.hero-art{position:absolute;inset:0}
.hero-art img{width:100%;height:100%;object-fit:cover;object-position:center 20%}
/* 左侧雾面渐变保证文字可读，右侧保留场景细节 */
.hero-scrim{position:absolute;inset:0;pointer-events:none;
  background:linear-gradient(90deg,
    rgba(240,248,255,.98) 0%,
    rgba(240,248,255,.90) 20%,
    rgba(240,248,255,.70) 32%,
    rgba(240,248,255,.30) 43%,
    rgba(240,248,255,.05) 53%,
    rgba(240,248,255,0) 62%);
}
.hero-scrim::after{content:"";position:absolute;inset:auto 0 0 0;height:120px;
  background:linear-gradient(180deg,rgba(240,248,255,0),rgba(240,248,255,.55))}
.hero-content{position:relative;z-index:2;height:100%;width:min(1600px,92%);margin:0 auto;
  display:flex;flex-direction:column;justify-content:center;padding-top:80px}
.hero-content>*{max-width:620px}
.hero-title{max-width:none;font-size:clamp(46px,5.4vw,80px);font-weight:900;line-height:1.15;letter-spacing:.015em;margin:22px 0 24px}
.hero-sub{font-size:clamp(15px,1.4vw,18px);color:var(--ink-2);line-height:1.9;max-width:480px}
.hero-cta{display:flex;gap:16px;margin-top:38px;flex-wrap:wrap}

/* 滚动提示 + 下一区块露出 */
.hero-scroll{position:absolute;left:50%;bottom:26px;transform:translateX(-50%);z-index:3;
  display:flex;flex-direction:column;align-items:center;gap:4px;color:var(--ink-2);
  font-size:12px;letter-spacing:.3em;animation:bob 2.2s ease-in-out infinite}
.hero-scroll svg{width:20px;height:20px}
@keyframes bob{0%,100%{transform:translate(-50%,0)}50%{transform:translate(-50%,8px)}}

/* ============================================================
   数据条：白色圆角卡上移，盖住 Hero 底部 → next-section peek
   ============================================================ */
.stats{position:relative;z-index:5;margin-top:-84px}
.stats-grid{background:var(--white);border-radius:28px 28px 0 0;box-shadow:0 -30px 60px -30px rgba(58,104,143,.25);
  display:grid;grid-template-columns:repeat(4,1fr);padding:40px 48px 34px;gap:24px}
.stat{display:flex;flex-direction:column;gap:2px;align-items:flex-start}
.stat strong{font-family:var(--font-num);font-size:clamp(30px,3.4vw,44px);font-weight:700;line-height:1.1;letter-spacing:.01em}
.stat span{font-size:13.5px;color:var(--ink-3);letter-spacing:.08em}

/* ============================================================
   核心功能：DLSS 画质配置与综合优化
   ============================================================ */
.features{background:var(--white);padding:80px 0 88px;scroll-margin-top:80px}
.features .sec-head{max-width:none;display:flex;justify-content:space-between;align-items:flex-end;gap:32px;margin-bottom:40px}
.features .sec-head h2{line-height:1.3}
.features .sec-sub{margin:0 0 4px;font-size:16px;line-height:1.8}
.features-layout{display:grid;grid-template-columns:minmax(0,.9fr) minmax(0,1.5fr);gap:24px}
.feat-dlss{position:relative;min-width:0;overflow:hidden;display:flex;flex-direction:column;padding:32px;border-radius:24px;background:linear-gradient(145deg,#EAF5FF,#F4FAFF);border:1px solid #D5E8F7}
.feat-kicker{color:var(--accent-ink);font-size:13px;font-weight:600;letter-spacing:.14em;margin-bottom:12px}
.feat-dlss h3{font-size:32px;line-height:1.3;margin-bottom:14px;letter-spacing:.01em}
.feat-dlss p{font-size:15px;line-height:1.9;color:var(--ink-2);text-wrap:pretty}
.resolution-art{position:relative;flex:1;min-height:200px;margin-top:24px;display:flex;align-items:center;justify-content:center}
.resolution-grid{position:absolute;inset:16px -4px 40px;background-image:linear-gradient(#A8CDEB35 1px,transparent 1px),linear-gradient(90deg,#A8CDEB35 1px,transparent 1px);background-size:18px 18px;mask-image:radial-gradient(ellipse,#000 15%,transparent 72%)}
.resolution-frame{position:absolute;width:184px;height:126px;border:1px solid #A8CDEB;border-radius:10px;transform:rotate(-8deg);background:#FFFFFF42}
.resolution-frame span{position:absolute;inset:10px;border:1px solid #B6D7F0;border-radius:7px;transform:translate(10px,7px)}
.resolution-frame span:nth-child(2){inset:20px;transform:translate(20px,14px)}
.resolution-frame span:nth-child(3){inset:30px;transform:translate(30px,21px)}
.resolution-art b{z-index:1;font-family:var(--font-num);font-size:38px;letter-spacing:.08em;color:var(--accent-ink)}
.resolution-caption{position:absolute;bottom:8px;color:var(--ink-3);font-size:12px;letter-spacing:.05em}
.feat-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0 24px}
.feat{position:relative;min-width:0;padding:23px 0 24px 52px;border-bottom:1px solid var(--line)}
.feat:nth-child(-n+2){padding-top:7px}
.feat:nth-last-child(-n+2){border-bottom:0;padding-bottom:4px}
.feat svg{position:absolute;left:0;top:24px;width:36px;height:36px;padding:8px;border-radius:10px;background:var(--paper);color:var(--accent-ink);transition:background .2s ease,transform .2s ease}
.feat:nth-child(-n+2) svg{top:8px}
.feat:hover svg{background:var(--accent-soft);transform:translateY(-2px)}
.feat h3{font-size:18px;font-weight:800;margin-bottom:8px;line-height:1.4}
.feat p{font-size:14px;color:var(--ink-3);line-height:1.8;text-wrap:pretty}
@media (prefers-reduced-motion:reduce){.feat svg{transition:none}.feat:hover svg{transform:none}}

/* ============================================================
   下载（浅蓝收尾区块）
   ============================================================ */
.download{background:#F0F8FF;color:#20364A;padding:64px 0;position:relative;overflow:hidden}
.download::before{content:"";position:absolute;top:-180px;right:-120px;width:520px;height:520px;border-radius:50%;
  background:radial-gradient(circle,rgba(100,169,216,.16),transparent 65%);pointer-events:none}
.download .wrap{position:relative;z-index:1}
.dl-grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.25fr);align-items:center;gap:64px}
.dl-copy .eyebrow{margin-bottom:16px}
.dl-copy h2{font-size:clamp(32px,3.4vw,46px);font-weight:900;line-height:1.25;letter-spacing:.01em}
.dl-intro{margin-top:20px;font-size:16px;line-height:1.9;color:var(--ink-2)}
.dl-card{min-width:0;background:#FFFFFF;border:1px solid #C9DFEF;border-radius:22px;padding:30px;box-shadow:0 24px 60px -32px rgba(58,104,143,.2)}
.dl-head{display:flex;align-items:center;gap:16px;margin-bottom:18px}
.dl-icon{width:60px;height:60px;object-fit:contain;flex:none}
.dl-head h3{font-size:22px;font-weight:900;color:var(--ink)}
.dl-head p{font-size:14px;color:#526F85;margin-top:5px;line-height:1.7}
.dl-badges{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:22px}
.dl-badges span{font-size:11.5px;color:#526F85;border:1px solid #C9DFEF;background:#E6F2FC;padding:5px 12px;border-radius:99px;letter-spacing:.05em}

/* ============================================================
   页脚
   ============================================================ */
.footer{background:#FFFFFF;color:#526F85;padding-top:40px}
.foot-grid{display:grid;grid-template-columns:minmax(0,1fr) auto auto;gap:56px;padding-bottom:28px}
.foot-brand .brand{color:var(--ink);margin-bottom:14px}
.foot-brand p{font-size:13.5px;color:#526F85}
.footer nav{display:grid;grid-template-columns:1fr;align-content:start;gap:12px 20px}
.footer nav:first-of-type{grid-template-columns:repeat(2,auto)}
.footer h5{grid-column:1/-1;color:#20364A;font-size:13.5px;letter-spacing:.16em}
.footer nav a{font-size:13px;color:#526F85;transition:color .2s;width:fit-content}
.footer nav a:hover{color:var(--ink)}
.foot-bar{display:flex;justify-content:space-between;gap:8px 24px;flex-wrap:wrap;padding:20px 0 24px;border-top:1px solid var(--line);font-size:12px;color:#526F85}
.foot-disclaimer{flex-basis:100%}

/* 下载问题与原生提示框 */
.dl-help{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-top:18px;padding-top:16px;border-top:1px solid var(--line);font-size:14px;color:var(--accent-ink)}
.dl-help>span:first-child{display:flex;align-items:center;gap:8px;font-weight:600}
.dl-help>span:last-child{font-size:13px;color:var(--ink-3)}
.dl-help svg{width:18px;height:18px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round}
.dl-help:hover>span:last-child{color:var(--accent-ink)}
html:has(.download-dialog[open]){overflow:hidden}
.download-dialog{width:min(960px,calc(100% - 40px));max-height:calc(100svh - 40px);margin:auto;padding:32px;border:1px solid var(--accent-line);border-radius:24px;background:var(--white);color:var(--ink);box-shadow:0 30px 100px #20364A40;overflow-y:auto;overscroll-behavior:contain}
.download-dialog::backdrop{background:rgba(24,45,65,.5);backdrop-filter:blur(6px)}
.download-dialog>.eyebrow{font-size:12px;margin-bottom:12px}
.download-dialog h2{font-size:28px;line-height:1.3;margin:0 36px 12px 0}
.download-dialog>p:not(.eyebrow){font-size:15px;color:var(--ink-2);line-height:1.8}
.download-tip-close{position:absolute;top:18px;right:18px;width:40px;height:40px;border-radius:12px;background:var(--paper);font-size:28px;line-height:1;color:var(--ink-2)}
.download-tip-close:hover{background:var(--accent-soft);color:var(--accent-ink)}
.download-tip-steps{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;margin-top:24px}
.download-tip-step{min-width:0;padding:14px;border-radius:16px;background:var(--paper);border:1px solid var(--line)}
.download-tip-step figcaption{display:flex;align-items:center;gap:8px;margin-bottom:14px;font-size:14px;font-weight:600;line-height:1.5}
.download-tip-step figcaption>span{display:grid;place-items:center;flex:none;width:25px;height:25px;border-radius:8px;background:var(--accent);color:var(--accent-ink);font-family:var(--font-num)}
.download-tip-step>a{display:flex;align-items:center;justify-content:center;height:230px;border-radius:8px;background:#FFFFFF;overflow:hidden;cursor:zoom-in}
.download-tip-step img{width:100%;height:100%;object-fit:contain}
.download-tip-actions{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-top:24px}
.download-tip-actions>span{font-size:13px;color:var(--ink-3)}
.dl-help:focus-visible,.dl-actions a:focus-visible,.download-dialog a:focus-visible,.download-dialog button:focus-visible{outline:2px solid var(--accent-ink);outline-offset:4px}
@media (max-width:620px){
  .download-dialog{width:calc(100% - 24px);max-height:calc(100svh - 24px);padding:24px 20px;border-radius:20px}
  .download-dialog h2{font-size:25px}
  .download-tip-steps{grid-template-columns:1fr;gap:12px;margin-top:20px}
  .download-tip-step>a{height:auto;max-height:none}
  .download-tip-step img{height:auto;max-height:300px}
  .download-tip-actions{align-items:stretch;flex-direction:column;margin-top:20px}
  .download-tip-actions>span{text-align:center}
  .download-tip-actions .btn{width:100%}
}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width:1080px){
  .features-layout{grid-template-columns:minmax(0,.85fr) minmax(0,1.4fr);gap:24px}
  .feat-dlss{padding:28px 24px}
  .feat-grid{gap:0 20px}
  .feat{padding-left:0}
  .feat svg{position:static;margin-bottom:12px}
  .stats-grid{padding:34px 36px}
}
@media (max-width:920px){
  .features-layout{grid-template-columns:1fr}
  .feat-dlss{display:grid;grid-template-columns:1fr .8fr;column-gap:24px;align-content:center}
  .feat-dlss .feat-kicker,.feat-dlss h3,.feat-dlss p{grid-column:1}
  .resolution-art{grid-column:2;grid-row:1/4;margin-top:0;align-self:stretch}
  .dl-grid{gap:32px;grid-template-columns:minmax(0,1fr) minmax(0,1.3fr)}
  .foot-grid{grid-template-columns:1fr 1fr;gap:28px}
  .foot-brand{grid-column:1/-1}
  .footer nav{justify-content:start;gap:12px 16px}
  .nav-inner{height:72px;gap:12px}
  .nav-cta{margin-left:auto;padding-left:0;border-left:0}
  .brand{gap:8px}
  .brand-mark{width:40px;height:40px}
  .nav-links{position:fixed;top:72px;left:0;right:0;flex-direction:column;gap:2px;padding:14px 20px 20px;
    border-radius:0;background:rgba(255,255,255,.97);backdrop-filter:blur(16px);box-shadow:0 30px 40px -30px rgba(58,104,143,.35);
    transform:translateY(-16px);opacity:0;pointer-events:none;transition:.28s ease}
  .nav-links.open{transform:none;opacity:1;pointer-events:auto}
  .nav-links{align-items:stretch}
  .nav-links a{padding:13px 16px;font-size:16px;border-radius:8px}
  .nav-links a:hover{background:var(--paper)}
  .nav-links a::after{display:none}
  .nav-burger{display:flex}
  .nav.open .nav-burger span:nth-child(1){transform:translateY(7px) rotate(45deg)}
  .nav.open .nav-burger span:nth-child(2){opacity:0}
  .nav.open .nav-burger span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
  .hero{height:100svh;min-height:720px}
  .hero-content{justify-content:flex-end;padding-top:72px;padding-bottom:120px}
  .hero-art{right:0}
  .hero-art img{object-position:center center}
  .hero-scrim{background:linear-gradient(180deg,
    rgba(240,248,255,.64) 0%,
    rgba(240,248,255,.20) 22%,
    rgba(240,248,255,.78) 46%,
    rgba(240,248,255,.94) 72%,
    var(--paper) 100%)}
  .hero-title{font-size:clamp(46px,11vw,72px)}
  .hero-scroll{display:none}
  .stats{margin-top:-64px}
  .stats-grid{grid-template-columns:repeat(2,1fr);border-radius:22px 22px 0 0}
}
@media (max-width:620px){
  .download{padding:40px 0}
  .dl-grid{grid-template-columns:1fr;gap:28px}
  .dl-card{padding:24px}
  .footer{padding-top:32px}
  .footer nav,.footer nav:first-of-type{grid-template-columns:1fr}
  .hero-title{font-size:clamp(36px,10.5vw,60px)}
  .features{padding:48px 0 56px;scroll-margin-top:72px}
  .features .sec-head{display:block;margin-bottom:28px}
  .features .sec-sub{margin-top:16px;font-size:15px}
  .features-layout{grid-template-columns:1fr;gap:28px}
  .feat-dlss{display:flex;padding:26px 24px}
  .feat-dlss h3{font-size:28px}
  .resolution-art{min-height:178px;margin-top:10px}
  .resolution-frame{width:164px;height:112px}
  .resolution-art b{font-size:34px}
  .feat-grid{gap:0 20px}
  .feat{padding:22px 0}
  .feat:nth-child(-n+2){padding-top:0}
  .feat h3{font-size:17px}
  .feat p{font-size:14px}
  .stats-grid{grid-template-columns:repeat(2,1fr)}
  .hero-cta .btn{width:100%}
  .foot-grid{grid-template-columns:1fr 1fr}
}