/* ============================================================
   重庆共方科技有限公司 官网全局样式
   风格：toB 庄重商务 · 深海军蓝为主 + 克制深金点缀
   方向 B：稳重、可信、大气，不使用轻佻亮色
   ============================================================ */

:root {
  /* 主色：深海军蓝系 */
  --navy-900: #0a1e3c;   /* 最深：页脚/大底色 */
  --navy-800: #0d2750;   /* 次深 */
  --navy-700: #123059;   /* 深板块 */
  --navy-600: #1a3f6b;
  --blue-700: #1e3f73;   /* 主按钮/强调深蓝 */
  --blue-600: #26548c;
  --blue-500: #2f6499;

  /* 点缀：克制深金（商务高端） */
  --gold-600: #a5812f;
  --gold-500: #b8943f;
  --gold-400: #c8a553;

  /* 中性 */
  --ink-900: #1a232e;
  --ink-800: #2a333d;
  --ink-700: #3a444e;
  --ink-600: #55606a;
  --ink-500: #6b7680;
  --ink-400: #8a949d;
  --ink-300: #b6bec6;
  --ink-100: #eef1f4;
  --line: #dce2e8;

  --bg-soft: #f4f6f9;    /* 浅灰蓝底 */
  --bg-card: #ffffff;

  /* 渐变 */
  --grad-primary: linear-gradient(160deg,#0a1e3c 0%, #0d2750 55%, #123059 100%);
  --grad-btn: linear-gradient(135deg,#1a3f6b 0%, #26548c 100%);
  --grad-gold: linear-gradient(135deg,#a5812f 0%, #b8943f 100%);

  --shadow-sm: 0 1px 3px rgba(13,32,64,.06), 0 1px 2px rgba(13,32,64,.04);
  --shadow-md: 0 6px 18px rgba(13,32,64,.10);
  --shadow-lg: 0 16px 40px rgba(13,32,64,.16);
  --radius: 8px;
  --radius-lg: 12px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: "PingFang SC","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;
  color: var(--ink-700);
  line-height: 1.75;
  background: var(--bg-soft);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }
ul, ol { list-style: none; }

.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ---------- 排版 ---------- */
h1,h2,h3,h4 { color: var(--navy-900); font-weight: 700; line-height: 1.35; }
.section { padding: 76px 0; }
.section-soft { background: var(--bg-soft); }
.section-white { background: #fff; }
.section-dark { background: var(--grad-primary); color: #e6ecf4; }
.section-title { text-align: center; margin-bottom: 14px; }
.section-title h2 { font-size: 32px; letter-spacing: 1px; }
.section-subtitle { text-align: center; color: var(--ink-500); max-width: 760px; margin: 0 auto 48px; font-size: 16px; }
.section-dark .section-title h2 { color: #fff; }
.section-dark .section-subtitle { color: #a9bcd6; }

.text-gold { color: var(--gold-500); }

/* 标题下划线 */
.title-bar { width: 56px; height: 3px; background: var(--grad-gold); border-radius: 2px; margin: 16px auto 0; }
.title-bar.left { margin: 16px 0 0; }

/* ---------- 顶部导航 ---------- */
.nav { position: sticky; top: 0; z-index: 100; background: #fff; border-bottom: 1px solid var(--line); box-shadow: 0 1px 6px rgba(13,32,64,.05); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 72px; }
.logo { display: flex; align-items: center; gap: 12px; }
.logo-mark {
  width: 42px; height: 42px; border-radius: 6px;
  background: var(--grad-primary); color: #fff; display: flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: 20px; border-bottom: 2px solid var(--gold-500);
}
.logo-img { width: 40px; height: 45px; object-fit: contain; display: block; }
.logo-text { line-height: 1.2; }
.logo-text strong { display: block; color: var(--navy-900); font-size: 20px; letter-spacing: 2px; }
.logo-text span { font-size: 10px; color: var(--ink-400); letter-spacing: 3px; }
.nav-menu { display: flex; align-items: center; gap: 4px; }
.nav-menu a {
  padding: 10px 15px; font-size: 15px; color: var(--ink-700); border-radius: 6px; font-weight: 500;
  position: relative;
}
.nav-menu a:hover { color: var(--blue-600); }
.nav-menu a.active { color: var(--blue-600); font-weight: 600; }
.nav-menu a.active::after { content:""; position:absolute; left:15px; right:15px; bottom:4px; height:2px; background: var(--gold-500); }
.nav-cta { display: flex; align-items: center; gap: 14px; }
.nav-tel { color: var(--navy-900); font-size: 16px; font-weight: 700; display: flex; align-items: center; gap: 6px; }
.nav-toggle { display: none; background: none; border: none; font-size: 26px; color: var(--navy-900); cursor: pointer; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 28px; border-radius: 6px; font-size: 15px; font-weight: 600;
  cursor: pointer; border: none; transition: all .25s; line-height: 1.3; letter-spacing: .5px;
}
.btn-primary { background: var(--grad-btn); color: #fff; box-shadow: 0 4px 12px rgba(20,50,100,.25); }
.btn-primary:hover { background: var(--navy-700); transform: translateY(-1px); box-shadow: 0 8px 18px rgba(20,50,100,.3); }
.btn-outline { border: 1.5px solid var(--blue-600); color: var(--blue-600); background: transparent; }
.btn-outline:hover { background: var(--blue-600); color: #fff; }
.btn-white { background: #fff; color: var(--navy-800); box-shadow: 0 4px 12px rgba(0,0,0,.15); }
.btn-white:hover { transform: translateY(-1px); }
.btn-lg { padding: 15px 36px; font-size: 16px; }
.btn-gold { background: var(--grad-gold); color: #fff; box-shadow: 0 4px 12px rgba(165,129,47,.3); }
.btn-gold:hover { filter: brightness(1.05); transform: translateY(-1px); }

/* ---------- Hero ---------- */
.hero { background: var(--grad-primary); position: relative; overflow: hidden; color: #eaf0f7; }
.hero::before {
  content:""; position:absolute; inset:0; opacity:.5; z-index:0; pointer-events:none;
  background:
    radial-gradient(700px 400px at 88% 12%, rgba(47,100,153,.35), transparent 60%),
    radial-gradient(600px 380px at 5% 95%, rgba(10,30,60,.6), transparent 55%);
}
.hero::after { content:""; position:absolute; inset:0; z-index:0; pointer-events:none; background-image: linear-gradient(rgba(255,255,255,.03) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.03) 1px, transparent 1px); background-size: 60px 60px; }
.hero-inner { position: relative; z-index: 1; display: grid; grid-template-columns: 1.15fr .85fr; gap: 48px; padding: 92px 24px 100px; align-items: center; }
.hero h1 { color: #fff; font-size: 42px; line-height: 1.3; margin-bottom: 20px; letter-spacing: 1px; }
.hero h1 .hl { color: var(--gold-400); }
.hero .lead { font-size: 18px; color: #c3d2e4; max-width: 620px; margin-bottom: 18px; line-height: 1.9; }
.hero .badge-line { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 30px; }
.hero .badge { border-left: 3px solid var(--gold-500); background: rgba(255,255,255,.05); padding: 6px 14px; font-size: 14px; color: #d7e2ef; }
.hero-cta { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-stats { display: flex; gap: 40px; margin-top: 46px; border-top: 1px solid rgba(255,255,255,.12); padding-top: 26px; }
.hero-stat b { display: block; font-size: 30px; color: #fff; }
.hero-stat b i { font-style: normal; color: var(--gold-400); font-size: 20px; }
.hero-stat span { font-size: 13px; color: #90a9c9; }

/* Hero 右侧产品族面板 */
.hero-product { background: rgba(255,255,255,.05); border: 1px solid rgba(255,255,255,.12); border-radius: var(--radius-lg); padding: 26px; }
.hero-product .hp-t { font-size: 14px; color: var(--gold-400); letter-spacing: 2px; margin-bottom: 18px; font-weight: 600; border-bottom: 1px solid rgba(255,255,255,.1); padding-bottom: 12px; }
.hero-product .hp-list { display: flex; flex-direction: column; gap: 10px; }
.hero-product .hp-item { display: flex; align-items: center; gap: 14px; padding: 12px 14px; border-left: 3px solid transparent; transition: .2s; }
.hero-product .hp-item:hover { background: rgba(255,255,255,.05); border-left-color: var(--gold-500); }
.hero-product .hp-item .hp-ic { width: 40px; height: 40px; border-radius: 6px; background: var(--grad-btn); display: flex; align-items: center; justify-content: center; flex-shrink: 0; color: #fff; font-weight: 700; border-bottom: 2px solid var(--gold-500); }
.hero-product .hp-item b { color: #fff; font-size: 15px; }
.hero-product .hp-item span { display: block; font-size: 12px; color: #9ab0cb; }

/* ---------- 卡片网格 ---------- */
.grid-3 { display: grid; grid-template-columns: repeat(3,1fr); gap: 26px; }
.grid-4 { display: grid; grid-template-columns: repeat(4,1fr); gap: 24px; }
.grid-2 { display: grid; grid-template-columns: repeat(2,1fr); gap: 28px; }
.card {
  background: var(--bg-card); border-radius: var(--radius); padding: 30px;
  box-shadow: var(--shadow-sm); border: 1px solid var(--line);
  /* 默认顶边线：浅金，保证白底也能看到；hover 变金粗线 */
  border-top: 3px solid #e6d9b6;
  transition: transform .3s, box-shadow .3s, border-color .3s, border-top-color .3s;
}
.section-soft .card { border-top-color: #d6c896; }
.card:hover { transform: translateY(-5px); box-shadow: var(--shadow-md); border-top-color: var(--gold-500); }
.card .card-ic { width: 54px; height: 54px; border-radius: 8px; display: flex; align-items: center; justify-content: center; margin-bottom: 20px; font-size: 26px; border: 1px solid; }
.ic-blue { background: #eef2f8; border-color: #d3ddea; color: var(--blue-600); }
.ic-navy { background: #eaf0f7; border-color: #c9d6e6; color: var(--navy-800); }
.ic-gold { background: #f7f2e4; border-color: #e6d9b6; color: var(--gold-600); }
.card h3 { font-size: 19px; margin-bottom: 12px; }
.card p { font-size: 14px; color: var(--ink-500); margin-bottom: 16px; line-height: 1.8; }
.card .link { color: var(--blue-600); font-weight: 600; font-size: 14px; display: inline-flex; align-items: center; gap: 4px; }
.card .link:hover { gap: 8px; color: var(--gold-600); }

/* 平台带 */
.platform-band { background: var(--grad-primary); border-radius: var(--radius-lg); color: #dfe8f3; padding: 44px 48px; position: relative; overflow: hidden; margin-bottom: 48px; border: 1px solid rgba(255,255,255,.08); }
.platform-band::before { content:""; position:absolute; right:-70px; top:-70px; width:220px; height:220px; border-radius:50%; background: rgba(47,100,153,.3); }
.platform-band h3 { color: #fff; font-size: 24px; margin-bottom: 14px; }
.platform-band h3 em { font-style: normal; color: var(--gold-400); }
.platform-band p { color: #b9c9dc; max-width: 820px; }
.platform-band .badges { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; position: relative; }
.platform-band .badges span { border: 1px solid rgba(255,255,255,.18); padding: 6px 14px; font-size: 13px; color: #dbe5f0; }
.platform-band .btn { margin-top: 24px; position: relative; }

/* 特征列表 */
.feat-item { display: flex; gap: 18px; padding: 22px 0; border-bottom: 1px solid var(--line); }
.feat-item:last-child { border-bottom: none; }
.feat-item .fi-ic { width: 48px; height: 48px; flex-shrink: 0; border-radius: 8px; background: #eef2f8; color: var(--blue-600); display: flex; align-items: center; justify-content: center; font-size: 22px; border: 1px solid #dbe3ee; }

/* 步骤 */
.steps { display: grid; grid-template-columns: repeat(5,1fr); gap: 16px; }
.step { text-align: center; position: relative; }
.step .num { width: 48px; height: 48px; margin: 0 auto 14px; border-radius: 6px; background: var(--grad-btn); color: #fff; font-weight: 700; display: flex; align-items: center; justify-content: center; font-size: 18px; border-bottom: 2px solid var(--gold-500); }
.step h4 { font-size: 16px; margin-bottom: 6px; }
.step .year { font-size: 22px; font-weight: 800; color: var(--gold-500); letter-spacing: 1px; line-height: 1.2; margin-bottom: 8px; }
.step .year.on { font-size: 13px; font-weight: 600; color: var(--ink-400); margin-top: 7px; letter-spacing: 0; }
.step p { font-size: 13px; color: var(--ink-500); }
.step:not(:last-child)::after { content:""; position:absolute; top:24px; left: calc(50% + 32px); width: calc(100% - 64px); height: 1px; background: var(--line); }

/* ---------- CTA ---------- */
.cta-band { background: var(--grad-primary); color: #fff; padding: 58px 0; text-align: center; position: relative; overflow: hidden; }
.cta-band::before { content:""; position:absolute; left:0; top:0; width:100%; height:3px; background: var(--grad-gold); }
.cta-band h2 { color: #fff; font-size: 30px; margin-bottom: 14px; letter-spacing: 1px; }
.cta-band p { color: #b9c9dc; margin-bottom: 28px; font-size: 16px; }

/* ---------- 页脚 ---------- */
.footer { background: var(--navy-900); color: #93a6bf; font-size: 14px; }
.footer-top { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1.2fr; gap: 40px; padding: 60px 0 44px; }
.footer h4 { color: #fff; font-size: 15px; margin-bottom: 18px; letter-spacing: 1px; position: relative; padding-bottom: 10px; }
.footer h4::after { content:""; position:absolute; left:0; bottom:0; width: 28px; height:2px; background: var(--gold-500); }
.footer ul li { margin-bottom: 11px; }
.footer ul li a:hover { color: var(--gold-400); }
.footer .f-logo { display: flex; align-items: center; gap: 12px; margin-bottom: 18px; }
.f-logo-img { width: 40px; height: 45px; object-fit: contain; display: block; }
.footer .f-about { color: #8297b3; margin-top: 18px; margin-bottom: 0; line-height: 1.9; font-size: 13px; width: 100%; text-align: justify; text-justify: inter-ideograph; }
.f-brand { display: flex; flex-direction: column; }
.f-qr { display: flex; align-items: center; gap: 12px; background: rgba(255,255,255,.04); border: 1px solid rgba(255,255,255,.08); border-radius: 6px; width: 100%; box-sizing: border-box; }
.f-qr img { width: 92px; height: 92px; display: block; background:#fff; padding:4px; border-radius:4px; }
.f-qr-text { line-height: 1.5; }
.f-qr-text .t1 { color:#a8bbd2; font-size: 12px; }
.f-qr-text .t2 { color: var(--gold-400); font-size: 15px; font-weight: 700; margin: 2px 0; letter-spacing: 1px; }
.f-qr-text .t3 { color:#6c83a3; font-size: 11px; }
.footer .f-contact li { display: flex; gap: 10px; align-items: flex-start; }
.footer .f-contact .t { color: #6c83a3; width: 40px; flex-shrink: 0; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.08); padding: 22px 0; display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; color: #607899; font-size: 13px; }
.footer-bottom a { color: #8297b3; }
.footer-bottom a:hover { color: var(--gold-400); }
.footer-beian { border-top: 1px solid rgba(255,255,255,.06); padding: 14px 0 26px; display: flex; justify-content: center; align-items: center; gap: 0; flex-wrap: wrap; color: #607899; font-size: 12px; }
.footer-beian a { color: #8297b3; display: inline-flex; align-items: center; }
.footer-beian a:hover { color: var(--gold-400); }
.beian-police { margin: 0 10px; }
.beian-police .police-shield { width: 20px; height: 20px; flex-shrink: 0; display: block; }

/* 悬浮咨询 */
.float-btn {
  position: fixed; right: 26px; bottom: 44px; z-index: 90;
  background: var(--navy-800); color: #fff; border-radius: 6px; padding: 14px 20px;
  box-shadow: var(--shadow-lg); font-weight: 600; display: flex; align-items: center; gap: 8px;
  font-size: 15px; transition: transform .25s; border-left: 3px solid var(--gold-500);
}
.float-btn:hover { transform: translateY(-3px); color: #fff; background: var(--navy-700); }
.float-btn .fb { width: 24px; height: 24px; border-radius: 4px; background: var(--gold-500); color: #fff; display: flex; align-items: center; justify-content: center; font-size: 14px; font-weight: 700; }

/* 弹窗 */
.modal-mask { position: fixed; inset: 0; background: rgba(7,18,36,.6); z-index: 200; display: none; align-items: center; justify-content: center; padding: 20px; }
.modal-mask.show { display: flex; }
.modal { background: #fff; border-radius: var(--radius-lg); max-width: 460px; width: 100%; padding: 34px; position: relative; box-shadow: var(--shadow-lg); max-height: 90vh; overflow:auto; border-top: 3px solid var(--gold-500); }
.modal .m-close { position: absolute; right: 16px; top: 12px; background: none; border: none; font-size: 26px; color: var(--ink-300); cursor: pointer; }
.modal h3 { margin-bottom: 8px; }
.modal .m-sub { color: var(--ink-500); font-size: 13px; margin-bottom: 22px; }

/* 表单 */
.form-group { margin-bottom: 16px; }
.form-group label { display: block; font-size: 13px; color: var(--ink-700); margin-bottom: 6px; font-weight: 500; }
.form-group input, .form-group select, .form-group textarea {
  width: 100%; padding: 11px 14px; border: 1px solid var(--line); border-radius: 6px; font-size: 14px;
  font-family: inherit; background: #fbfcfd; transition: border .2s;
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus { outline: none; border-color: var(--blue-600); }
.form-group textarea { resize: vertical; min-height: 90px; }
.form-note { font-size: 12px; color: var(--ink-400); margin-top: 6px; }
.form-ok { text-align: center; padding: 24px 0; }
.form-ok .ok-ic { width: 58px; height: 58px; border-radius: 50%; background: #eef2f8; color: var(--blue-600); font-size: 28px; display: flex; align-items: center; justify-content: center; margin: 0 auto 16px; border: 1px solid #d5dfec; }
.form-ok h4 { margin-bottom: 8px; }

/* ---------- 内页 ---------- */
.page-hero { background: var(--grad-primary); color: #dfe8f3; padding: 62px 0; position: relative; overflow: hidden; }
.page-hero::before { content:""; position:absolute; right:-70px; top:-70px; width:260px; height:260px; border-radius:50%; background: rgba(47,100,153,.3); }
.page-hero h1 { color: #fff; font-size: 34px; margin-bottom: 12px; letter-spacing: 1px; }
.page-hero p { color: #b3c5da; max-width: 800px; font-size: 16px; }
.page-hero .crumb { font-size: 13px; color: #7e9abc; margin-bottom: 18px; }
.page-hero .crumb a:hover { color: var(--gold-400); }

.crumb-bar { padding: 20px 0 0; font-size: 13px; color: var(--ink-500); }
.crumb-bar a { color: var(--ink-600); }
.crumb-bar a:hover { color: var(--blue-600); }
.crumb-bar .sep { margin: 0 8px; color: var(--ink-300); }

.sub-nav { display: flex; gap: 8px; flex-wrap: wrap; margin: 28px 0; }
.sub-nav a { padding: 10px 20px; border-radius: 6px; border: 1px solid var(--line); font-size: 14px; font-weight: 500; color: var(--ink-600); background:#fff; }
.sub-nav a:hover { border-color: var(--blue-600); color: var(--blue-600); }
.sub-nav a.active { background: var(--grad-btn); border-color: transparent; color: #fff; box-shadow: 0 4px 10px rgba(20,50,100,.25); }

.layout-2col { display: grid; grid-template-columns: 250px 1fr; gap: 40px; align-items: start; }
.side-nav { position: sticky; top: 92px; }
.side-nav .sn-title { font-size: 15px; font-weight: 700; color: #fff; padding: 13px 18px; background: var(--navy-800); border-left: 3px solid var(--gold-500); }
.side-nav ul { border: 1px solid var(--line); background:#fff; overflow:hidden; }
.side-nav ul a { display: block; padding: 12px 18px; font-size: 14px; border-bottom: 1px solid var(--line); color: var(--ink-600); border-left: 3px solid transparent; }
.side-nav ul li:last-child a { border-bottom: none; }
.side-nav ul a:hover { color: var(--blue-600); }
.side-nav ul a.active { color: var(--blue-600); font-weight: 600; border-left-color: var(--gold-500); background: #f4f7fb; }

.content-body { background: #fff; border-radius: var(--radius); padding: 40px; box-shadow: var(--shadow-sm); border: 1px solid var(--line); min-height: 60vh; }
.content-body h2 { font-size: 24px; margin: 8px 0 20px; padding-bottom: 14px; border-bottom: 1px solid var(--line); }
.content-body h3 { font-size: 20px; margin: 30px 0 14px; color: var(--navy-900); }
.content-body h4 { font-size: 16px; margin: 22px 0 10px; color: var(--blue-700); }
.content-body p { margin-bottom: 16px; color: var(--ink-700); font-size: 15px; }
.content-body ul, .content-body ol { margin: 0 0 18px 22px; }
.content-body ul li, .content-body ol li { margin-bottom: 8px; font-size: 15px; list-style: disc; }
.content-body ol li { list-style: decimal; }
.content-body blockquote { border-left: 4px solid var(--gold-500); background: #faf6ea; padding: 14px 18px; margin: 0 0 18px; border-radius: 0 6px 6px 0; color: var(--ink-700); }
.content-body table { width:100%; border-collapse: collapse; margin: 0 0 20px; font-size: 14px; }
.content-body th, .content-body td { border: 1px solid var(--line); padding: 10px 13px; text-align: left; }
.content-body th { background: #eef2f8; color: var(--navy-900); font-weight: 600; }

/* FAQ */
.faq-item { border: 1px solid var(--line); border-radius: 8px; margin-bottom: 12px; overflow: hidden; background: #fff; }
.faq-item summary { cursor: pointer; padding: 16px 20px; font-weight: 600; color: var(--navy-900); font-size: 16px; display: flex; justify-content: space-between; align-items: center; gap: 12px; }
.faq-item summary::after { content: "+"; font-size: 22px; color: var(--gold-500); transition: transform .2s; }
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item .faq-a { padding: 0 20px 20px; color: var(--ink-700); font-size: 15px; }
.faq-item .faq-a p { margin-bottom: 10px; }

.tag { display: inline-block; padding: 3px 10px; border-radius: 4px; font-size: 12px; background: #eef2f8; color: var(--blue-700); margin-right: 6px; margin-bottom: 6px; border: 1px solid #dce4ef; }
.tag-gold { background: #f7f2e4; color: var(--gold-600); border-color: #e6d9b6; }

/* 徽标墙 */
.logo-wall { display: flex; flex-wrap: wrap; gap: 16px; justify-content: center; align-items:center; }
.logo-wall .lw { background:#fff; border:1px solid var(--line); border-radius:6px; padding: 18px 26px; color: var(--ink-500); font-weight:600; font-size:15px; box-shadow: var(--shadow-sm); letter-spacing:1px; }

/* 文章列表 */
.article-list .article-item { display:flex; gap:22px; padding: 24px 0; border-bottom:1px solid var(--line); }
.article-list .article-item:last-child { border-bottom:none; }
.article-item .ai-cat { width:128px; height:90px; border-radius:8px; flex-shrink:0; background: var(--grad-primary); color:#fff; display:flex; align-items:center; justify-content:center; font-weight:700; font-size:15px; text-align:center; padding:6px; line-height:1.4; border-bottom:2px solid var(--gold-500); }
.article-item h3 { font-size:18px; margin-bottom:8px; }
.article-item h3 a:hover { color: var(--blue-600); }
.article-item .ai-ex { color: var(--ink-500); font-size:14px; margin-bottom:10px; }
.article-item .ai-date { font-size:12px; color: var(--ink-400); }

.lead-para { font-size: 17px; color: var(--ink-600); line-height: 2; }

/* 占位图 */
.placeholder-img { background: linear-gradient(135deg,#eef1f4,#e3e9ef); border: 1.5px dashed #bcc8d4; color: #78889a; display:flex; align-items:center; justify-content:center; min-height:200px; border-radius:8px; font-size:14px; text-align:center; padding:20px; flex-direction:column; gap:8px; }
.placeholder-img small { font-size:12px; color:#9aa8b6; }

/* ====== 响应式 ====== */
@media (max-width: 992px) {
  .grid-4 { grid-template-columns: repeat(2,1fr); }
  .grid-3 { grid-template-columns: repeat(2,1fr); }
  .grid-2 { grid-template-columns: 1fr; }
  .steps { grid-template-columns: repeat(3,1fr); gap: 28px; }
  .step:not(:last-child)::after { display:none; }
  .footer-top { grid-template-columns: 1fr 1fr; }
  .hero-inner { grid-template-columns: 1fr; padding: 64px 24px 72px; }
  .layout-2col { grid-template-columns: 1fr; }
  .side-nav { position: static; }
  .hero h1 { font-size: 34px; }
}
@media (max-width: 768px) {
  .grid-3, .grid-4, .grid-2, .steps { grid-template-columns: 1fr; }
  .section { padding: 52px 0; }
  .nav-menu {
    display: none; position: absolute; top: 72px; left: 0; right: 0; background: #fff;
    flex-direction: column; align-items: stretch; padding: 10px 20px 20px; box-shadow: var(--shadow-md); border-top:1px solid var(--line);
  }
  .nav-menu.open { display: flex; }
  .nav-menu a { padding: 14px 12px; border-bottom: 1px solid var(--line); border-radius: 0; }
  .nav-menu a.active::after { display:none; }
  .nav-menu a.active { color: var(--gold-600); }
  .nav-cta { display: none; }
  .nav-toggle { display: block; }
  .footer-top { grid-template-columns: 1fr; }
  .section-title h2 { font-size: 26px; }
  .page-hero h1 { font-size: 28px; }
  .hero h1 { font-size: 30px; }
  .hero-stats { flex-wrap: wrap; gap: 24px; }
  .platform-band { padding: 32px 24px; }
  .content-body { padding: 24px; }
}