/* Arts-power 官网全站样式 · 工业深蓝 · 扁线矩形 motif */
:root{
  --navy:#0B2A55; --blue:#0033A0; --steel:#3B64A1; --ink:#17233B;
  --gray:#4E5A6E; --line:#D9E1EE; --bg:#FFFFFF; --bg-soft:#F3F6FB;
  --paper:#FFFFFF; --footer:#0A1D3A;
  --radius:6px;               /* 扁线矩形 motif：统一小半径 */
  --font:"PingFang SC","Microsoft YaHei","Segoe UI",Roboto,Helvetica,Arial,sans-serif;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:var(--font);color:var(--ink);background:var(--bg);line-height:1.7;font-size:16px}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
ul{list-style:none}
.container{max-width:1180px;margin:0 auto;padding:0 24px}

/* 入场动效（transform + opacity only，含 reduced-motion 回退） */
.reveal{opacity:0;transform:translateY(22px);transition:opacity .55s ease,transform .55s ease}
.reveal.in{opacity:1;transform:none}
@media (prefers-reduced-motion: reduce){
  .reveal{opacity:1;transform:none;transition:none}
  html{scroll-behavior:auto}
}

/* 顶部导航 */
.site-header{position:sticky;top:0;z-index:100;background:var(--bg-soft)}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:68px}
.logo{display:flex;align-items:center}
img.logo-combo{height:42px;width:auto}
.logo-mark,img.logo-mark{width:36px;height:36px;border-radius:6px;object-fit:cover}
.main-nav{display:flex;gap:26px;align-items:center}
.main-nav a{font-size:15px;color:var(--ink);padding:5px 0;transition:color .18s}
.main-nav a:hover,.main-nav a.active{color:var(--blue)}
.lang-switch{background:var(--bg-soft);border-radius:var(--radius);padding:5px 14px;font-size:13.5px;font-weight:600;color:var(--navy)}
.nav-toggle{display:none;width:40px;height:36px;background:none;border:none;cursor:pointer;padding:8px 8px}
.nav-toggle span{display:block;width:100%;height:2.5px;background:var(--navy);position:relative;transition:.2s}
.nav-toggle span::before,.nav-toggle span::after{content:"";position:absolute;left:0;width:100%;height:2.5px;background:var(--navy)}
.nav-toggle span::before{top:-8px}
.nav-toggle span::after{top:8px}

/* 按钮：扁线矩形 motif —— 方角小半径实心块 */
.btn{display:inline-block;padding:14px 32px;border-radius:var(--radius);font-size:15.5px;font-weight:600;transition:background .18s,color .18s}
.btn-primary{background:var(--blue);color:#fff}
.btn-primary:hover{background:var(--navy)}
.btn-ghost{border:1.5px solid rgba(255,255,255,.65);color:#fff}
.btn-ghost:hover{background:#fff;color:var(--navy)}
.btn-light{background:#fff;color:var(--navy)}
.btn-light:hover{background:#DCE7F9}

/* Hero：纯色深蓝底 + 大字号标题 + 大幅媒体 */
.hero{background:var(--navy);color:#fff;padding:88px 0 96px;overflow:hidden}
.hero-inner{display:block}
.hero h1{font-size:clamp(32px,7.4vw,96px);line-height:1.12;font-weight:700;letter-spacing:.01em;max-width:14em}
.hero p.lead{margin-top:28px;font-size:19px;max-width:36em;color:#C7D5EC}
.hero-actions{margin-top:36px;display:flex;gap:14px;flex-wrap:wrap}
.hero-media{margin-top:56px;border-radius:var(--radius);overflow:hidden;background:#071E3E;max-width:820px}
.hero-media video,.hero-media img{width:100%;height:auto;aspect-ratio:16/9;display:block;object-fit:cover}
.hero-stats{margin-top:72px;display:grid;grid-template-columns:repeat(4,1fr);gap:28px;max-width:1000px}
.hero-stat{border-left:4px solid var(--blue);padding-left:18px}   /* 扁线矩形 motif */
.hero-stat b{font-size:clamp(26px,2.6vw,36px);display:block;line-height:1.2}
.hero-stat span{font-size:14px;color:#9FB2D2;display:block;margin-top:4px}

/* 内页 Hero */
.page-hero{background:var(--navy);color:#fff;padding:72px 0 80px}
.ph-inner{display:grid;grid-template-columns:7fr 5fr;gap:48px;align-items:center}
.page-hero h1{font-size:clamp(34px,6vw,84px);line-height:1.14}
.page-hero p{margin-top:18px;color:#C7D5EC;max-width:32em;font-size:17px}
.page-hero .btn{margin-top:28px}
.ph-media{border-radius:var(--radius);overflow:hidden}
.ph-media img{width:100%;height:clamp(260px,30vw,460px);object-fit:cover;display:block}
.ph-media img.fit-contain{object-fit:contain;background:transparent}

/* 区块通用 */
.section{padding:92px 0}
.section.soft{background:var(--bg-soft)}
.section-head{max-width:760px;margin-bottom:52px}
.section-head h2{font-size:clamp(26px,3vw,38px);line-height:1.25;color:var(--navy);font-weight:700}
.section-head p{color:var(--gray);margin-top:14px;font-size:17px}
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:48px;align-items:center}
.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}

/* 卡片：顶部扁线色条 + 图片，无阴影无浮起 */
.card{background:var(--bg-soft);border-radius:var(--radius);overflow:hidden}
.section.soft .card{background:var(--bg)}
.card::before{content:"";display:block;width:56px;height:8px;background:var(--blue);margin:28px 0 0 28px;border-radius:2px} /* motif */
.card h3{font-size:19px;color:var(--navy);margin:14px 28px 10px}
.card p{font-size:16px;color:var(--gray);margin:0 28px 22px}
.card>.card-media{height:200px;order:-1}
.card>.card-media img{width:100%;height:100%;object-fit:cover}
.card ul{margin:0 28px 24px}
.card ul li{font-size:16px;color:var(--gray);padding:4px 0 4px 22px;position:relative}
.card ul li::before{content:"";position:absolute;left:0;top:13px;width:12px;height:3px;border-radius:1px;background:var(--blue)} /* 扁线 motif */

/* 数据大字（无卡片框） */
.stat-strip{display:grid;grid-template-columns:repeat(4,1fr);gap:28px}
.stat{border-left:4px solid var(--blue);padding-left:18px}
.stat b{font-size:clamp(28px,3vw,44px);color:var(--navy);display:block;line-height:1.15}
.stat span{font-size:14.5px;color:var(--gray);display:block;margin-top:4px}

/* 产品参数表 */
.spec-table{width:100%;border-collapse:collapse;font-size:15px;background:var(--bg)}
.spec-table th,.spec-table td{padding:12px 16px;border-bottom:1px solid var(--line);text-align:left}
.spec-table th{color:var(--navy);font-weight:600;width:38%}
.spec-table tr:last-child td{border-bottom:none}

/* 图片块 */
.figure{border-radius:var(--radius);overflow:hidden}
.grid-2>figure{order:-1}
.figure img{width:100%;height:auto;object-fit:cover}
.figure figcaption{font-size:13px;color:var(--gray);padding:10px 14px;background:var(--bg-soft)}

/* 客户墙 */
.customer-wall{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.customer-item{background:var(--bg-soft);border-radius:var(--radius);padding:26px 10px;text-align:center;font-weight:700;color:var(--navy);font-size:17px;letter-spacing:1px}
.customer-item small{display:block;font-weight:400;color:var(--gray);font-size:13px;margin-top:4px;letter-spacing:0}

/* 步骤/时间线 */
.timeline{border-left:3px solid var(--line);margin-left:8px;padding-left:26px}
.timeline li{position:relative;padding-bottom:24px}
.timeline li::before{content:"";position:absolute;left:-31px;top:8px;width:16px;height:5px;border-radius:2px;background:var(--blue)} /* 扁线 motif */
.timeline b{color:var(--navy)}
.timeline span{display:block;font-size:16px;color:var(--gray)}

/* FAQ */
.faq-item{border-radius:var(--radius);background:var(--bg-soft);margin-bottom:14px;overflow:hidden}
.faq-item summary{cursor:pointer;padding:18px 22px;font-weight:600;color:var(--navy);list-style:none;display:flex;justify-content:space-between;align-items:center;font-size:16.5px}
.faq-item summary::after{content:"+";font-size:22px;color:var(--blue);font-weight:400}
.faq-item[open] summary::after{content:"−"}
.faq-item .faq-a{padding:0 22px 18px;color:var(--gray);font-size:16px}

/* CTA 横幅：纯色深蓝 */
.cta-band{background:var(--navy);border-radius:var(--radius);color:#fff;padding:56px 52px;display:flex;justify-content:space-between;align-items:center;gap:24px;flex-wrap:wrap}
.cta-band h2{font-size:clamp(24px,2.6vw,32px)}
.cta-band p{color:#C7D5EC;margin-top:10px}

/* 页脚 */
.site-footer{background:var(--footer);color:#B9C6DC;padding:64px 0 28px;margin-top:96px;font-size:14.5px}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1.4fr;gap:36px}
.site-footer h4{color:#fff;font-size:15px;margin-bottom:14px}
.footer-brand{height:40px;width:auto;margin-bottom:20px}
.site-footer a:hover{color:#fff}
.site-footer li{padding:4px 0}
.footer-bottom{margin-top:40px;padding-top:20px;font-size:13px;color:#8B9AB5;display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap}

/* 视频网格 */
.video-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.video-item{border-radius:var(--radius);overflow:hidden;background:#000;align-self:start}
.video-item video{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;display:block;background:#000}
.video-item figcaption{font-size:13px;color:var(--gray);padding:9px 12px;background:var(--bg-soft)}

/* 响应式 */
@media (max-width:900px){
  .grid-2>figure{order:0}
  .main-nav{display:none;position:absolute;top:68px;left:0;right:0;background:var(--bg);flex-direction:column;padding:18px 24px;border-bottom:1px solid var(--line);gap:16px}
  .main-nav.open{display:flex}
  .nav-toggle{display:block}
  .hero{padding:64px 0 72px}
  .hero-inner{grid-template-columns:1fr;gap:36px}
  .ph-inner{grid-template-columns:1fr;gap:28px}
  .page-hero{padding:52px 0 60px}
  .ph-media img{height:200px}
  .hero-media video,.hero-media img{min-height:220px}
  .hero-stats{grid-template-columns:repeat(2,1fr);gap:20px;margin-top:48px}
  .stat-strip{grid-template-columns:repeat(2,1fr)}
  .grid-3,.grid-4{grid-template-columns:1fr}
  .grid-2{grid-template-columns:1fr}
  .customer-wall{grid-template-columns:repeat(2,1fr)}
  .footer-grid{grid-template-columns:1fr 1fr}
  .video-grid{grid-template-columns:1fr}
  .cta-band{padding:36px 28px}
}

/* 视频封面 + 点击播放（避免手机浏览器 poster 黑屏） */
.video-item{position:relative;cursor:pointer}
.video-cover{width:100%;height:auto;aspect-ratio:16/10;object-fit:cover;display:block}
.video-item.vertical .video-cover{aspect-ratio:9/14;max-width:420px;margin:0 auto}
.video-item.vertical video{width:min(100%,420px);left:50%;transform:translateX(-50%);inset-block:0}
.play-btn{position:absolute;top:calc((100% - 46px)/2);left:50%;transform:translate(-50%,-50%);width:64px;height:64px;border-radius:50%;background:rgba(11,42,85,.85);border:none;pointer-events:none}
.play-btn::after{content:"";position:absolute;left:24px;top:19px;border-style:solid;border-width:13px 0 13px 22px;border-color:transparent transparent transparent #fff}
.video-item:hover .play-btn{background:var(--blue)}

/* 客户品牌瓦片墙（proof board） */
.logo-tiles{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}
.tile{background:var(--bg-soft);border-radius:var(--radius);min-height:150px;display:flex;align-items:center;justify-content:center;padding:24px}
.section.soft .tile{background:var(--bg)}
.tile img{max-height:52px;max-width:72%;object-fit:contain}
.tile-name{font-weight:700;font-size:22px;color:var(--navy);letter-spacing:1px}
.tile-lead{background:var(--navy)!important;color:#fff;grid-column:span 2;flex-direction:column;align-items:flex-start;justify-content:flex-start;padding:28px}
.tile-lead b{font-size:clamp(22px,2.2vw,30px);line-height:1.25}
.tile-lead span{color:#C7D5EC;font-size:14.5px;margin-top:10px}
@media (max-width:900px){
  .logo-tiles{grid-template-columns:repeat(2,1fr)}
  .tile{min-height:110px;padding:16px}
  .tile img{max-height:40px}
  .tile-name{font-size:18px}
  .tile-lead{grid-column:span 2}
}

/* 技术页 hero：流程图完整显示，不裁切 */
.ph-media.contain img{object-fit:contain;background:transparent;height:clamp(300px,32vw,500px)}
.ph-inner.wide-media{grid-template-columns:0.9fr 1.1fr;gap:72px}

/* 转矩安全功能框架：步骤流 */
.safety-grid{grid-template-columns:1.15fr .85fr}
.safety-flow ol{list-style:none;border-left:3px solid var(--line);margin:0 0 18px;padding-left:26px}
.safety-flow li{position:relative;padding-bottom:20px}
.safety-flow li::before{content:"";position:absolute;left:-31px;top:8px;width:16px;height:5px;border-radius:2px;background:var(--blue)}
.safety-flow b{color:var(--navy)}
.safety-flow span{display:block;font-size:16px;color:var(--gray)}
.safety-flow .flow-note{margin:0;color:var(--gray);font-size:16px}

/* 应用领域：杂志式交错大图 */
.app-feature{display:grid;grid-template-columns:1.35fr 1fr;gap:56px;align-items:center;margin-bottom:72px}
.app-feature.flip{grid-template-columns:1fr 1.35fr}
.app-feature.flip .af-media{order:2}
.app-feature.flip .af-text{order:1}
.af-media{border-radius:var(--radius);overflow:hidden;background:var(--bg-soft)}
.af-media img{width:100%;aspect-ratio:16/10;object-fit:cover;display:block}
.af-media.tall img{aspect-ratio:4/5;max-height:620px;object-position:50% 55%}
.af-index{display:inline-flex;align-items:center;gap:10px;font-size:13.5px;font-weight:600;letter-spacing:.06em;color:var(--steel);margin-bottom:14px}
.af-index::before{content:"";width:26px;height:6px;border-radius:2px;background:var(--blue)}
.af-text h3{font-size:clamp(24px,2.4vw,32px);line-height:1.28;color:var(--navy);font-weight:700}
.af-text p{margin-top:14px;color:var(--gray);font-size:16.5px}
.app-points{margin-top:20px}
.app-points li{position:relative;padding:6px 0 6px 20px;font-size:15.5px;color:var(--ink)}
.app-points li::before{content:"";position:absolute;left:0;top:15px;width:10px;height:3px;border-radius:1px;background:var(--blue)}
.app-pair{display:grid;grid-template-columns:1fr 1fr;gap:24px}
.app-pair figure{border-radius:var(--radius);overflow:hidden}
.app-pair img{width:100%;aspect-ratio:4/3;object-fit:cover;display:block}
.app-pair figcaption{padding:14px 2px 0}
.app-pair b{display:block;color:var(--navy);font-size:17px;margin-bottom:4px}
.app-pair span{font-size:15px;color:var(--gray)}
@media (max-width:860px){
  .app-feature,.app-feature.flip{grid-template-columns:1fr;gap:24px;margin-bottom:56px}
  .app-feature.flip .af-media,.app-feature.flip .af-text{order:0}
  .af-media.tall img{aspect-ratio:4/3;max-height:none}
  .app-pair{grid-template-columns:1fr}
}

/* 视频区：4 竖排 + 横版通栏 */
.video-grid.v4{grid-template-columns:repeat(4,1fr)}
.video-item.feature{margin-top:18px;align-self:stretch;max-width:980px;margin-left:auto;margin-right:auto}
.video-item.feature .video-cover{aspect-ratio:16/9}
.video-item.feature video{position:absolute}
@media (max-width:860px){.video-grid.v4{grid-template-columns:repeat(2,1fr)}}

/* 视频区：五列等宽，横竖同高 */
.video-grid.v5{grid-template-columns:repeat(5,1fr);gap:14px;align-items:start}
.video-grid.v5 .video-item{display:flex;flex-direction:column}
.video-grid.v5 .video-cover,.video-grid.v5 .video-item.vertical .video-cover{aspect-ratio:9/14;max-width:none;margin:0;object-fit:cover}
.video-grid.v5 .video-item video{position:absolute}
.video-grid.v5 .video-item figcaption{margin-top:auto;min-height:52px;display:flex;align-items:center}
@media (max-width:1100px){.video-grid.v5{grid-template-columns:repeat(3,1fr)}}
@media (max-width:860px){.video-grid.v5{grid-template-columns:repeat(2,1fr)}}

/* 产品理念：关键词标签行 */
.idea-tags{display:flex;flex-wrap:wrap;gap:16px;margin-top:36px}
.idea-tags{justify-content:space-between}
.idea-tags span{flex:1;text-align:center;background:var(--bg);border:1.5px solid var(--line);border-left:4px solid var(--blue);border-radius:var(--radius);padding:14px 10px;font-weight:600;color:var(--navy);font-size:15.5px;letter-spacing:.06em}

/* 产品理念：产品墙通栏图 */
.wall-figure{max-width:860px;margin:8px auto 0;overflow:visible}
.wall-figure img{display:block;width:100%;height:auto;border-radius:var(--radius);object-fit:contain}
.wall-figure figcaption{text-align:center;background:none}