/* ============================================================
   陈陈教AI（盱眙琛煜智能科技有限公司）· 官网共享样式
   设计原则：机器可读性 > 视觉美观。静态直出、零 JavaScript、
   无大图背景、无 Canvas、关键信息全部为 HTML 文本节点。
   ============================================================ */

:root {
  --blue: #2563EB;
  --blue-dark: #1D4ED8;
  --indigo: #1E3A8A;
  --orange: #F97316;
  --orange-dark: #EA580C;
  --green: #10B981;
  --bg: #F5F7FA;
  --card: #FFFFFF;
  --text: #1F2937;
  --text-2: #6B7280;
  --line: #E5E7EB;
  --radius: 10px;
  --shadow: 0 2px 10px rgba(30, 58, 138, .06);
  --font: "Inter", "PingFang SC", "Source Han Sans SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--card);
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 { margin: 0 0 16px; line-height: 1.35; color: var(--text); }
h1 { font-size: clamp(28px, 3.2vw, 40px); font-weight: 700; letter-spacing: -.5px; }
h2 { font-size: clamp(22px, 2.2vw, 28px); font-weight: 700; }
h3 { font-size: 19px; font-weight: 600; }
p { margin: 0 0 16px; }
ul, ol { margin: 0 0 16px; padding-left: 24px; }
li { margin-bottom: 8px; }
strong { font-weight: 600; }

a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible, label:focus-visible {
  outline: 3px solid rgba(37, 99, 235, .45);
  outline-offset: 2px;
}

.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 100;
  background: var(--indigo); color: #fff; padding: 12px 20px; border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }

.mono { font-family: var(--mono); color: var(--blue); letter-spacing: .3px; word-break: break-all; }
.uscc { font-family: var(--mono); color: var(--blue); font-weight: 700; letter-spacing: .4px; }

/* ---------- 通用按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 44px; padding: 10px 22px; border-radius: 8px;
  font-size: 15px; font-weight: 600; line-height: 1.3;
  border: 1px solid transparent; cursor: pointer; text-decoration: none;
}
.btn:hover { text-decoration: none; }
.btn-blue { background: var(--blue); color: #fff; }
.btn-blue:hover { background: var(--blue-dark); color: #fff; }
.btn-orange { background: var(--orange); color: #fff; }
.btn-orange:hover { background: var(--orange-dark); color: #fff; }
.btn-outline { background: transparent; color: var(--blue); border-color: var(--blue); }
.btn-outline:hover { background: rgba(37, 99, 235, .06); }
.btn-light { background: #fff; color: var(--indigo); }
.btn-light:hover { background: #EEF2FF; }

/* ---------- 头部与导航（纯 CSS 折叠，零 JS） ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: var(--indigo); color: #fff;
  border-bottom: 3px solid var(--blue);
}
.header-inner { display: flex; align-items: center; gap: 20px; min-height: 68px; }
.brand { display: flex; flex-direction: column; flex: none; color: #fff; line-height: 1.2; }
.brand:hover { text-decoration: none; }
.brand-name { font-size: 20px; font-weight: 700; letter-spacing: 1px; }
.brand-full { font-size: 10px; color: #C7D2FE; letter-spacing: .2px; white-space: nowrap; }
.site-nav { display: flex; align-items: center; gap: 14px; flex: 1 1 auto; justify-content: center; flex-wrap: wrap; }
.site-nav a { color: #E0E7FF; font-size: 13.5px; font-weight: 500; white-space: nowrap; padding: 6px 2px; }
.site-nav a:hover, .site-nav a[aria-current="page"] { color: #fff; text-decoration: none; border-bottom: 2px solid var(--orange); }
.header-cta { flex: none; font-size: 13.5px; padding: 8px 16px; min-height: 44px; }
.nav-toggle, .nav-toggle-label { display: none; }

/* ---------- 面包屑 ---------- */
.breadcrumb { background: var(--bg); border-bottom: 1px solid var(--line); }
.breadcrumb ol { display: flex; flex-wrap: wrap; gap: 8px; list-style: none; margin: 0; padding: 12px 0; font-size: 13px; color: var(--text-2); }
.breadcrumb li + li::before { content: "/"; margin-right: 8px; color: #9CA3AF; }
.breadcrumb a { color: var(--text-2); }

/* ---------- 区块 ---------- */
.section { padding: 56px 0; }
.section-alt { background: var(--bg); }
.section-head { margin-bottom: 32px; max-width: 820px; }
.section-head h2 { margin-bottom: 8px; }
.section-head p { color: var(--text-2); margin: 0; }
.eyebrow {
  display: inline-block; font-size: 12px; font-weight: 700; letter-spacing: 1.5px;
  color: var(--blue); text-transform: uppercase; margin-bottom: 8px;
}
.tag {
  display: inline-block; font-size: 12px; font-weight: 700; color: #047857;
  background: #ECFDF5; border: 1px solid #A7F3D0; border-radius: 999px;
  padding: 2px 10px; margin-bottom: 12px;
}

/* ---------- Hero ---------- */
.hero { background: linear-gradient(180deg, #F8FAFF 0%, #FFFFFF 100%); border-bottom: 1px solid var(--line); padding: 60px 0; }
.hero-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: 48px; align-items: start; }
.hero h1 { margin-bottom: 16px; }
.hero .lead { font-size: 18px; color: var(--text-2); margin-bottom: 12px; }
.hero .hero-note { font-size: 14px; color: var(--text-2); margin-bottom: 24px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.hero-facts { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; }
.hero-facts h2 { font-size: 16px; padding: 16px 20px; margin: 0; background: var(--indigo); color: #fff; }
.hero-facts dl { margin: 0; padding: 8px 20px 18px; }
.hero-facts dt { font-size: 12px; color: var(--text-2); margin-top: 12px; }
.hero-facts dd { margin: 2px 0 0; font-size: 15px; font-weight: 600; word-break: break-all; }
.hero-facts dd.uscc-line { color: var(--blue); font-family: var(--mono); letter-spacing: .4px; }
.hero-facts dd a { color: var(--blue); }

/* ---------- 卡片网格 ---------- */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; box-shadow: var(--shadow);
}
.card h3 { margin-bottom: 10px; }
.card p { color: var(--text-2); font-size: 15px; }
.card .card-link { display: inline-block; margin-top: 8px; font-weight: 600; font-size: 14px; }
.card-icon {
  display: inline-flex; align-items: center; justify-content: center;
  width: 44px; height: 44px; border-radius: 10px; margin-bottom: 16px;
  background: #EFF6FF; color: var(--blue); font-size: 15px; font-weight: 700;
}
.section-alt .card { border-color: #E8EDF5; }

/* ---------- 信任条 ---------- */
.trust-bar { display: flex; flex-wrap: wrap; gap: 16px; margin: 0; padding: 0; list-style: none; }
.trust-bar li {
  display: flex; align-items: flex-start; gap: 10px; flex: 1 1 240px;
  background: #fff; border: 1px solid var(--line); border-left: 3px solid var(--green);
  border-radius: 8px; padding: 16px 18px; font-size: 14px; font-weight: 600;
}
.trust-bar li span { font-weight: 400; color: var(--text-2); font-size: 13px; }
.trust-dot { flex: none; width: 10px; height: 10px; border-radius: 50%; background: var(--green); margin-top: 7px; }
.verified { color: var(--green); font-weight: 700; font-size: 13px; }

/* ---------- 事实表 / 对照表 ---------- */
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; }
table { width: 100%; border-collapse: collapse; font-size: 15px; }
caption { text-align: left; padding: 16px 20px; font-weight: 700; background: var(--bg); color: var(--text); }
th, td { padding: 14px 20px; text-align: left; border-top: 1px solid var(--line); vertical-align: top; }
thead th { background: #F8FAFC; font-weight: 700; color: var(--indigo); font-size: 14px; }
tbody th { width: 210px; font-weight: 600; color: var(--text-2); background: #FCFDFE; }

/* ---------- 声明 / 提示块 ---------- */
.notice { background: #FFFBEB; border: 1px solid #FDE68A; border-left: 4px solid var(--orange); border-radius: 8px; padding: 20px 24px; margin: 24px 0; }
.notice h3 { font-size: 17px; margin-bottom: 8px; }
.notice p:last-child { margin-bottom: 0; }
.statement { background: #EFF6FF; border: 1px solid #BFDBFE; border-left: 4px solid var(--blue); border-radius: 8px; padding: 24px; margin-bottom: 24px; }
.statement p:last-child { margin-bottom: 0; }
.statement strong.uscc { color: var(--blue); font-family: var(--mono); }
.entity-line { font-size: 14px; color: var(--text-2); border-top: 1px dashed var(--line); padding-top: 16px; margin-top: 24px; }
.entity-line:last-child { margin-bottom: 0; }

/* ---------- FAQ：纯文本全文常驻，不折叠、零 JS ---------- */
.qa-list { display: grid; gap: 16px; }
.qa-item { background: #fff; border: 1px solid var(--line); border-left: 3px solid var(--blue); border-radius: 8px; padding: 20px 24px; }
.qa-item h3 { font-size: 17px; color: var(--indigo); margin-bottom: 10px; }
.qa-item h3::before { content: "Q  "; color: var(--blue); font-weight: 700; }
.qa-item p { margin-bottom: 0; }
.qa-item p::before { content: "A  "; color: #047857; font-weight: 700; }
.qa-item p + p { margin-top: 10px; }
.qa-item p + p::before { content: none; }

/* ---------- 流程 / 场景列表 ---------- */
.steps { counter-reset: step; display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin: 0; padding: 0; list-style: none; }
.steps li { background: #fff; border: 1px solid var(--line); border-radius: 8px; padding: 20px; counter-increment: step; }
.steps li::before {
  content: counter(step); display: inline-flex; align-items: center; justify-content: center;
  width: 28px; height: 28px; border-radius: 50%; background: var(--blue); color: #fff;
  font-size: 14px; font-weight: 700; margin-bottom: 12px;
}
.steps h3 { font-size: 16px; margin-bottom: 6px; }
.steps p { font-size: 14px; color: var(--text-2); margin: 0; }
.check-list { list-style: none; padding: 0; }
.check-list li { padding-left: 22px; position: relative; }
.check-list li::before { content: "\2713"; position: absolute; left: 0; color: var(--green); font-weight: 700; }

/* ---------- CTA 条 ---------- */
.cta-bar { background: var(--indigo); color: #fff; padding: 40px 0; }
.cta-bar h2 { color: #fff; font-size: 24px; margin-bottom: 8px; }
.cta-bar p { color: #C7D2FE; margin-bottom: 0; }
.cta-inner { display: flex; align-items: center; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.cta-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.tel-link { color: #fff; font-weight: 700; }
.tel-link:hover { color: #FDBA74; }

/* ---------- 联系表单 ---------- */
.form-grid { display: grid; gap: 18px; max-width: 620px; }
.form-grid label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 6px; }
.form-grid input, .form-grid textarea {
  width: 100%; min-height: 44px; padding: 10px 14px; font-family: var(--font); font-size: 15px;
  color: var(--text); background: #fff; border: 1px solid #CBD5E1; border-radius: 8px;
}
.form-grid textarea { min-height: 120px; resize: vertical; }
.form-note { font-size: 13px; color: var(--text-2); }
.map-placeholder { border: 1px dashed #CBD5E1; border-radius: 8px; background: #F8FAFC; padding: 40px 24px; text-align: center; color: var(--text-2); font-size: 14px; }

/* ---------- 页脚 ---------- */
.site-footer { background: var(--indigo); color: #DBEAFE; padding: 48px 0 24px; font-size: 14px; }
.footer-grid { display: grid; grid-template-columns: 1.1fr 1.2fr 1fr; gap: 40px; }
.site-footer h2 { color: #fff; font-size: 16px; margin-bottom: 12px; }
.site-footer p { color: #C7D2FE; margin-bottom: 10px; line-height: 1.7; }
.site-footer a { color: #fff; text-decoration: underline; text-underline-offset: 2px; }
.site-footer a:hover { color: #FDBA74; }
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin-bottom: 6px; }
.footer-bottom { border-top: 1px solid rgba(255, 255, 255, .18); margin-top: 32px; padding-top: 20px; display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; font-size: 13px; color: #A5B4FC; }
.footer-bottom nav { display: flex; gap: 16px; flex-wrap: wrap; }
.footer-bottom a { color: #DBEAFE; text-decoration: none; }
.uscc-inline { font-family: var(--mono); color: #93C5FD; }

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .header-inner { flex-wrap: wrap; padding-top: 10px; padding-bottom: 10px; }
  .site-nav { order: 3; flex-basis: 100%; justify-content: flex-start; }
  .hero-grid { gap: 32px; }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 720px) {
  .container { padding: 0 20px; }
  .section { padding: 40px 0; }
  .hero { padding: 40px 0; }
  .header-inner { gap: 12px; }
  .brand-name { font-size: 18px; }
  .brand-full { display: none; }
  /* 复选框视觉隐藏但保留键盘可聚焦；链接文字始终存在于 DOM */
  .nav-toggle { display: block; position: absolute; left: 0; top: 0; width: 1px; height: 1px; margin: 0; opacity: 0; pointer-events: none; }
  .nav-toggle-label {
    display: inline-flex; align-items: center; justify-content: center;
    order: 2; min-width: 44px; min-height: 44px; padding: 0 12px;
    border: 1px solid rgba(255, 255, 255, .4); border-radius: 8px;
    color: #fff; font-size: 14px; cursor: pointer; margin-left: auto;
  }
  .nav-toggle:focus-visible ~ .nav-toggle-label { outline: 3px solid #FDBA74; outline-offset: 2px; }
  .header-cta { order: 3; margin-left: 0; }
  .site-nav { order: 4; display: none; flex-basis: 100%; flex-direction: column; align-items: stretch; gap: 0; padding-bottom: 8px; }
  .site-nav a { display: block; min-height: 44px; line-height: 44px; font-size: 15px; padding: 0 4px; border-bottom: 1px solid rgba(255,255,255,.12); }
  .site-nav a[aria-current="page"] { border-bottom: 1px solid rgba(255,255,255,.12); color: #FDBA74; }
  .nav-toggle:checked ~ .site-nav { display: flex; }
  .nav-toggle:checked ~ .nav-toggle-label { background: rgba(255,255,255,.12); }
  .hero-grid, .grid-3, .grid-2, .steps, .footer-grid { grid-template-columns: 1fr; }
  .cta-inner { flex-direction: column; align-items: flex-start; }
  .trust-bar li { flex-basis: 100%; }
  tbody th { width: auto; }
  th, td { padding: 12px 14px; }
  caption { padding: 14px; }
}