/* 基础：页面尺寸、字体和全局变量 */
:root {
  --blue:#1967eb;
  --content-width:1200px;
  --content-gutter:24px;
  --text:#111111;
  --muted:#545454;
  --line:#e9edf3;
  --light:#f5f8fc;
  --nav-height:68px;
  --radius:8px;
  --space-1:8px;
  --space-2:12px;
  --space-3:16px;
  --space-4:24px;
  --space-5:32px;
  --space-6:48px;
  --space-7:64px;
  --space-8:80px;
  --space-9:96px;
  --space-10:120px;
  --shadow-soft:0 2px 8px rgba(0,0,0,0.04), 0 6px 16px rgba(0,0,0,0.07);
  --shadow-hover:0 8px 24px rgba(0,0,0,0.08);
  --transition:transform 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease, color 0.3s ease;
}
* { box-sizing:border-box; }
html { scroll-behavior:smooth; scroll-padding-top:var(--nav-height); }
body { margin:0; padding-top:var(--nav-height); color:var(--muted); font-family:"PingFang SC","Microsoft YaHei",Arial,sans-serif; font-size:14px; line-height:1.55; background:#fff; }
a { color:inherit; text-decoration:none; }
img { display:block; max-width:100%; border-radius:var(--radius);}
.container { width:min(var(--content-width),calc(100% - (var(--content-gutter) * 2))); margin:0 auto; }
.section { padding:var(--space-9) 0; }
.section-heading { text-align:center; margin-bottom:var(--space-7); }
.section-heading h2 { margin:0 0 8px; color:#111; font-size:30px; line-height:1.25; font-weight:700; }
.section-heading p { margin:0; color:var(--muted); font-size:13px; }

/* 顶部导航：始终固定在视口顶端，跳转与滚动时保持可见。 */
.site-header { position:fixed; top:0; right:0; left:0; z-index:20; height:var(--nav-height); background:rgba(255,255,255,.96); border-bottom:1px solid #eef1f5; box-shadow:0 2px 9px rgba(34,53,83,.03); }
.nav-wrap { width:min(var(--content-width),calc(100% - (var(--content-gutter) * 2))); height:100%; margin:0 auto; display:flex; align-items:center; justify-content:space-between; }
.brand { display:inline-flex; gap:8px; align-items:center; font-size:16px; font-weight:700; white-space:nowrap; }
.brand img { width:30px; height:auto; border-radius:0; box-shadow:none; }
.main-nav { height:100%; display:flex; align-items:center; gap:42px; }
.nav-link { position:relative; height:100%; padding-top:24px; color:#161b23; font-size:13px; transition:color 0.3s ease; }
.nav-link::after { position:absolute; right:0; bottom:0; left:0; height:3px; content:""; background:transparent; }
.nav-link:hover,.nav-link.active { color:var(--blue); }
.nav-link.active::after { background:var(--blue); }
.nav-toggle { display:none; width:42px; height:38px; border:0; background:transparent; cursor:pointer; }
.nav-toggle span { display:block; width:22px; height:2px; margin:5px auto; background:#182233; transition:.2s; }

/* 首屏：设计稿的浅蓝色背景和左右内容布局 */
.hero { min-height:440px; padding:84px 0 76px; background:linear-gradient(180deg,#dbeeff 0%,#eaf5ff 38%,#f7fbff 72%,#fff 100%); }
.hero-content { display:flex; align-items:center; justify-content:space-between; gap:88px; }
.hero-copy { flex:1 1 0; min-width:0; max-width:570px; padding-left:3px; }
.hero-image { flex:1 1 0; min-width:0; width:100%; height:auto; object-fit:contain; }
.hero h1 { margin:0 0 16px; color:#111; font-size:clamp(23px,3.75vw,45px); line-height:1.24; letter-spacing:0; font-weight:800; white-space:nowrap; }
.hero h1 em { color:var(--blue); font-style:normal; }
.hero p { max-width:510px; margin:0; color:var(--muted); font-size:14px; }

/* 服务体系：交错图文能力说明 */
.solutions { padding-bottom:80px; }
.capability-list { display:grid; gap:70px; }
.capability { display:grid; grid-template-columns:1fr 1fr; align-items:center; gap:92px; min-height:255px; }
.capability-copy { max-width:470px; }
.capability h3 { margin:0 0 18px; color:#111; font-size:25px; line-height:1.28; }
.capability p { margin:0 0 18px; color:var(--muted); font-size:13px; }
.capability ul { margin:0; padding:0; list-style:none; color:var(--muted); font-size:13px; line-height:2; }
.capability li::before { display:inline-block; width:19px; content:"✓"; color:#6ca2ff; font-weight:700; }
.capability img { width:100%; }
.text-left .capability-copy { justify-self:start; }
.text-left img { justify-self:end; }
.image-left img { justify-self:start; }
.image-left .capability-copy { justify-self:end; }

/* App：功能卡片、下载入口和手机样机 */
.app-section { background:var(--light); padding-bottom:70px; }
.app-section .section-heading { margin-bottom:48px; }
.app-content { display:flex; align-items:center; justify-content:center; gap:var(--space-10); }
.app-details { width:510px; }
.feature-grid { display:grid; grid-template-columns:repeat(2,minmax(0,1fr)); column-gap:var(--space-3); row-gap:20px; }
/* 商知 App 功能卡：柔和阴影与上浮凸起效果 */
.app-section .feature-grid article { padding:18px 16px; background:#fff; border:1px solid #e9edf4; border-radius:var(--radius); box-shadow:0 3px 10px rgba(24,37,58,.07); transition:transform 0.3s ease, box-shadow 0.3s ease; }
.feature-icon { display:block; width:30px; height:30px; margin-bottom:8px; padding:6px; border-radius:7px; background:#edf2ff; object-fit:contain; }
.feature-grid h3 { margin:0 0 3px; color:#111; font-size:14px; }
.feature-grid p { margin:0; color:var(--muted); font-size:11px; line-height:1.45; }
.download-row { display:flex; align-items:center; gap:17px; margin-top:27px; }
.download-qr { width:91px; height:91px; border:1px solid #e3e8ef; border-radius:8px; object-fit:cover; }
.download-row strong { color:#111; font-size:15px; }
.download-row p { margin:1px 0 9px; color:var(--muted); font-size:11px; }
.store-buttons { display:flex; gap:9px; }
.store-buttons a { display:flex; min-width:95px; align-items:center; justify-content:center; gap:5px; padding:7px 9px; border-radius:5px; color:#fff; text-align:center; background:#2e70ee; font-size:11px; transition:var(--transition); }
.store-buttons img { width:30px; height:30px; border-radius:0; object-fit:contain; }
.store-buttons a span { display:flex; flex-direction:column; align-items:flex-start; line-height:1.05; }
.store-buttons a small { margin-top:2px; font-size:9px; opacity:.9; }
.phone-image { width:270px; border-radius:0; box-shadow:none; filter:drop-shadow(0 9px 7px rgba(36,47,71,.16)); }

/* 客户案例：两列图文卡片 */
.cases { padding-top:88px; }
.cases .section-heading { margin-bottom:47px; }
.case-grid { display:grid; grid-template-columns:repeat(2,1fr); gap:26px; }
.case-card { overflow:hidden; }
.case-card__media { overflow:hidden; aspect-ratio:580 / 310; }
.case-card__media img { width:100%; height:100%; object-fit:cover; border-radius:0; transform:scale(1.08); transition:transform 0.32s ease; }
.case-card__body { position:relative; z-index:1; padding:14px 15px 16px; background:#fff; }
.case-card h3 { margin:0 0 3px; color:#111; font-size:15px; }
.case-card p { margin:0; color:var(--muted); font-size:11px; }

/* 合作咨询：居中的表单区域 */
.contact { padding:94px 0 92px; background:var(--light); }
.contact .section-heading { margin-bottom:42px; }
.contact-form { width:480px; max-width:100%; margin:0 auto; padding:24px; border:1px solid #e5eaf0; border-radius:8px; background:#fff; box-shadow:0 5px 13px rgba(42,60,81,.08); }
.contact-form label { display:block; margin-bottom:12px; color:var(--muted); font-size:12px; font-weight:600; }
.contact-form i { color:#e15353; font-style:normal; }
.contact-form input,.contact-form textarea { width:100%; margin-top:5px; padding:10px 12px; border:1px solid #dfe6ef; border-radius:3px; outline:0; color:#222b36; font:12px inherit; transition:border-color .2s,box-shadow .2s; }
.contact-form input { height:38px; }
.contact-form textarea { min-height:82px; height:82px; overflow:hidden; resize:none; }
.contact-form input:focus,.contact-form textarea:focus { border-color:#71a0f5; box-shadow:0 0 0 3px rgba(63,120,234,.12); }
.contact-form .field-invalid input,.contact-form .field-invalid textarea { border-color:#d84a4a; box-shadow:0 0 0 3px rgba(216,74,74,.1); }
.contact-form .field-invalid input:focus,.contact-form .field-invalid textarea:focus { border-color:#d84a4a; box-shadow:0 0 0 3px rgba(216,74,74,.12); }
.field-error { display:block; min-height:16px; margin-top:4px; color:#d84a4a; font-size:11px; font-weight:400; line-height:1.45; }
.contact-form button { width:100%; height:40px; border:0; border-radius:3px; color:#fff; background:var(--blue); cursor:pointer; font:13px inherit; transition:var(--transition); }
.contact-form button:disabled { opacity:.68; cursor:wait; transform:none; box-shadow:none; }

/* 交互：保持克制的卡片与按钮反馈 */
@media (hover:hover) {
  /* 仅商知 App 卡片在悬停时凸起，避免影响页面其他卡片 */
  .app-section .feature-grid article:hover { transform:translateY(-5px); box-shadow:0 12px 25px rgba(24,37,58,.16); }
  .store-buttons a:hover,.contact-form button:not(:disabled):hover { transform:translateY(-2px); box-shadow:0 6px 14px rgba(25,103,235,.2); background:#1958d8; }
  .back-to-top:hover { transform:translateY(-3px); box-shadow:0 8px 20px rgba(25,103,235,.3); }
}

/* 案例图片：父容器裁切溢出，图片自身承担圆角与轻微放大 */
.case-card:hover .case-card__media img { transform:scale(1.12); }

/* 客户案例：卡片保持简洁的边框与悬停反馈 */
.case-card {
  position:relative;
  overflow:hidden;
  border-radius:10px;
  background:#fff;
  box-shadow:0 3px 12px rgba(24,37,58,.08);
  transition:transform .3s ease,box-shadow .3s ease;
}
@media (hover:hover) { .case-card:hover { transform:translateY(-7px); box-shadow:0 14px 27px rgba(24,37,58,.14); } }

/* 首屏与产品解决方案：最近父容器裁切图片放大时的溢出范围 */
.hero-content,
.capability {
  overflow:hidden;
}

/* 首屏与产品解决方案图片：悬停轻微放大并取消图片阴影 */
.hero-image,
.capability img {
  transition:transform 0.3s ease, box-shadow 0.3s ease;
}
.hero-image:hover,
.capability img:hover {
  box-shadow:none;
  transform:scale(1.04);
}
.form-notice { min-height:16px; margin:6px 0 0; color:#398353; text-align:center; font-size:12px; }

/* 表单反馈弹窗：成功/失败共用一套简约容器 */
.feedback-modal { position:fixed; inset:0; z-index:50; display:grid; place-items:center; padding:var(--space-4); background:rgba(17,17,17,.18); opacity:0; transition:opacity .22s ease; }
.feedback-modal[hidden] { display:none; }
.feedback-modal.is-open { opacity:1; }
.feedback-modal__panel { position:relative; width:min(360px,100%); padding:32px 28px 27px; border:1px solid var(--line); border-top:3px solid var(--blue); border-radius:var(--radius); background:#fff; box-shadow:var(--shadow-soft); text-align:center; transform:translateY(8px); transition:transform .22s ease; }
.feedback-modal.is-open .feedback-modal__panel { transform:translateY(0); }
.feedback-modal.is-success .feedback-modal__panel { border-top-color:#398353; }
.feedback-modal.is-error .feedback-modal__panel { border-top-color:#d84a4a; }
.feedback-modal__close { position:absolute; top:9px; right:11px; width:28px; height:28px; border:0; border-radius:50%; color:#687384; background:transparent; cursor:pointer; font-size:21px; line-height:1; }
.feedback-modal__close:hover { color:var(--text); background:#f0f3f7; }
.feedback-modal__mark { display:grid; place-items:center; width:34px; height:34px; margin:0 auto 12px; border-radius:50%; color:#fff; background:#398353; font-size:20px; }
.feedback-modal__mark::before { content:"✓"; }
.feedback-modal.is-error .feedback-modal__mark { background:#d84a4a; }
.feedback-modal.is-error .feedback-modal__mark::before { content:"!"; }
.feedback-modal__panel h3 { margin:0 0 7px; color:var(--text); font-size:18px; }
.feedback-modal__message { margin:0; color:var(--muted); font-size:13px; line-height:1.6; }
.site-footer { padding:25px 20px; color:#8d98aa; text-align:center; background:#121d31; font-size:11px; }
.site-footer a:hover { color:#fff; }

/* 动效：区块内容随滚动轻微上移淡入 */
.reveal { opacity:0; transform:translateY(20px); transition:opacity 0.65s ease, transform 0.65s cubic-bezier(.2,.65,.3,1); }
.reveal.is-visible { opacity:1; transform:translateY(0); }
/* 案例卡片入场保持原节奏，边框悬停使用独立的 0.4 秒动画 */
.case-card.reveal,
.case-card.reveal.is-visible { transition:opacity 0.3s ease, transform 0.3s ease, box-shadow 0.4s ease; }

/* 回到顶部按钮：默认隐藏，超过首屏阈值后由 JS 添加可见状态 */
.back-to-top { position:fixed; right:32px; bottom:32px; z-index:30; display:grid; place-items:center; width:46px; height:46px; padding:0; border:0; border-radius:50%; color:#fff; background:var(--blue); box-shadow:0 4px 14px rgba(25,103,235,.24); cursor:pointer; font-size:25px; line-height:1; opacity:0; visibility:hidden; pointer-events:none; transform:translateY(12px); transition:opacity 0.4s ease, transform 0.4s ease, visibility 0s linear 0.4s; }
.back-to-top.is-visible { opacity:1; visibility:visible; pointer-events:auto; transform:translateY(0); transition:opacity 0.4s ease, transform 0.4s ease; }

/* 响应式：平板保持双栏比例，手机调整为单列 */
@media (max-width:900px) {
  :root { --nav-height:62px; }
  .section { padding:68px 0; }.section-heading { margin-bottom:44px; }.section-heading h2 { font-size:26px; }
  .hero { min-height:auto; padding:64px 0; }.hero-content { gap:42px; }.hero-image { width:42%; }
  .capability { gap:48px; }.capability h3 { font-size:21px; }.capability-list { gap:54px; }
  .app-content { gap:60px; }.app-details { width:54%; }.phone-image { width:220px; }
}
@media (max-width:768px) {
  .container,.nav-wrap { width:calc(100% - (var(--content-gutter) * 2)); }.brand { font-size:14px; }.brand img { width:27px; }
  .site-header { background:#fff; }
  .nav-toggle { display:block; z-index:2; }.main-nav { position:absolute; top:100%; right:0; left:0; display:none; width:auto; height:auto; padding:10px var(--content-gutter) 15px; border-bottom:1px solid #e8edf3; background:#fff; box-shadow:0 8px 12px rgba(24,37,58,.09); }.main-nav.open { display:flex; flex-direction:column; gap:0; }.nav-link { width:100%; height:auto; padding:12px 5px; font-size:16px; font-weight:700; text-align:left; }.nav-link::after { display:none; }.nav-toggle.open span:nth-child(1) { transform:translateY(7px) rotate(45deg); }.nav-toggle.open span:nth-child(2) { opacity:0; }.nav-toggle.open span:nth-child(3) { transform:translateY(-7px) rotate(-45deg); }
  .hero { padding:47px 0 52px; }.hero-content { flex-direction:column; gap:30px; align-items:flex-start; }.hero-copy { width:100%; }.hero p { font-size:13px; }.hero-image { width:100%; max-width:460px; align-self:center; }
  .section { padding:55px 0; }.section-heading { margin-bottom:36px; }.section-heading h2 { font-size:23px; }.section-heading p { font-size:12px; }
  .capability-list { gap:46px; }.capability,.capability.image-left { grid-template-columns:1fr; gap:25px; }.capability-copy,.text-left .capability-copy,.image-left .capability-copy { max-width:none; justify-self:stretch; order:1; }.capability img,.text-left img,.image-left img { justify-self:stretch; order:2; }.image-left img { order:2; }.capability h3 { margin-bottom:11px; font-size:20px; }.capability p,.capability ul { font-size:12px; }
  .app-content { flex-direction:column; gap:35px; }.app-details { width:100%; }.phone-image { width:230px; }.feature-grid { grid-template-columns:1fr; row-gap:16px; }.app-section .feature-grid article { padding:15px 16px; }.download-row { justify-content:center; gap:13px; }.store-buttons { flex-wrap:wrap; }.download-qr { width:82px; height:82px; }
  .case-grid { grid-template-columns:1fr; gap:17px; }.case-card__body { padding:13px 13px 15px; }.contact { padding-bottom:62px; }.contact-form { padding:19px; }.site-footer { padding:19px; }
  .back-to-top { right:24px; bottom:24px; }
}

@media (prefers-reduced-motion:reduce) {
  html { scroll-behavior:auto; }
  *,*::before,*::after { transition-duration:.01ms !important; animation-duration:.01ms !important; }
  .reveal { opacity:1; transform:none; }
  .feedback-modal,.feedback-modal__panel { transition:none; }
}