/* MES × AI 落地页样式。
   零外部依赖：无 web 字体、无位图、无 JS 动画库。视觉全部用 CSS 渐变 + 内联 SVG。
   海外机器直连也能秒开，整站资源仍在几十 KB 量级。 */
*, *::before, *::after { box-sizing: border-box; }

:root {
  /* 深色底 + 青蓝主色。制造业/工控的视觉语言：网格、示波、数据流 */
  --bg: #070b14;
  --bg-1: #0b1220;
  --bg-2: #0f1a2e;
  --panel: rgba(17, 27, 46, 0.72);
  --panel-solid: #111b2e;

  --ink: #eef3fb;
  --ink-soft: #a8b6cc;
  --ink-mute: #74839c;

  --line: rgba(126, 160, 214, 0.16);
  --line-strong: rgba(126, 160, 214, 0.32);

  --brand: #38bdf8;
  --brand-2: #6366f1;
  --brand-ink: #0a1220;
  --glow: rgba(56, 189, 248, 0.35);

  --err: #ff7a6b;
  --ok: #4ade80;

  --radius: 14px;
  --wrap: 1140px;
}

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

body {
  margin: 0;
  font: 16px/1.75 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--bg);
  overflow-x: hidden;
}

/* ---------- 全局背景：三层叠加的极光光晕 + 网格 ---------- */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(900px 600px at 12% -5%, rgba(56, 189, 248, 0.20), transparent 62%),
    radial-gradient(760px 520px at 88% 8%, rgba(99, 102, 241, 0.22), transparent 60%),
    radial-gradient(680px 680px at 50% 108%, rgba(20, 184, 166, 0.14), transparent 62%),
    linear-gradient(180deg, #070b14, #0a1120 45%, #070b14);
}

/* 工程图纸网格，极淡，只在暗底上透出来 */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(126, 160, 214, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(126, 160, 214, 0.055) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(ellipse 100% 65% at 50% 25%, #000 30%, transparent 78%);
  -webkit-mask-image: radial-gradient(ellipse 100% 65% at 50% 25%, #000 30%, transparent 78%);
}

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 22px; position: relative; }
.wrap.narrow { max-width: 720px; }

h1, h2, h3 { line-height: 1.32; margin: 0 0 16px; font-weight: 700; letter-spacing: -0.015em; }
h1 { font-size: clamp(28px, 5.4vw, 46px); }
h2 { font-size: clamp(22px, 3.4vw, 31px); }
h3 { font-size: 17.5px; }
p { margin: 0 0 16px; }
.muted { color: var(--ink-mute); }
.small { font-size: 13px; }

/* 渐变强调文字 */
.grad {
  background: linear-gradient(96deg, #7dd3fc, #38bdf8 38%, #818cf8 78%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
}

/* ---------- 导航 ---------- */
.nav {
  position: sticky; top: 0; z-index: 30;
  background: rgba(7, 11, 20, 0.72);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 62px; gap: 14px; }
.logo { display: inline-flex; align-items: center; gap: 9px; font-weight: 750; letter-spacing: 0.02em; }
.logo svg { flex: none; }
.nav-links { display: inline-flex; align-items: center; gap: 18px; }
.nav-link {
  font-size: 14px; font-weight: 600; color: #9fb2c6; text-decoration: none;
  transition: color 0.18s ease;
  white-space: nowrap;
}
.nav-link:hover { color: #cbe9fb; }
.nav-cta {
  font-size: 14px; font-weight: 600; color: #cbe9fb; text-decoration: none;
  border: 1px solid var(--line-strong); padding: 8px 15px; border-radius: 9px;
  background: rgba(56, 189, 248, 0.08);
  transition: background 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
  white-space: nowrap;
}
.nav-cta:hover {
  background: rgba(56, 189, 248, 0.18);
  border-color: var(--brand);
  box-shadow: 0 0 0 4px rgba(56, 189, 248, 0.10);
}

/* ---------- Hero ---------- */
.hero { padding: 76px 0 68px; border-bottom: 1px solid var(--line); position: relative; }
.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 46px;
  align-items: center;
}
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 12.5px; color: #7dd3fc; font-weight: 650;
  letter-spacing: 0.10em; margin-bottom: 16px;
  padding: 6px 13px; border-radius: 999px;
  border: 1px solid rgba(56, 189, 248, 0.28);
  background: rgba(56, 189, 248, 0.09);
}
.eyebrow .dot {
  width: 7px; height: 7px; border-radius: 50%; background: var(--brand);
  box-shadow: 0 0 0 0 var(--glow);
  animation: pulse 2.4s ease-out infinite;
}
@keyframes pulse {
  0%   { box-shadow: 0 0 0 0 rgba(56, 189, 248, 0.55); }
  70%  { box-shadow: 0 0 0 9px rgba(56, 189, 248, 0); }
  100% { box-shadow: 0 0 0 0 rgba(56, 189, 248, 0); }
}

.lede { font-size: 16.5px; color: var(--ink-soft); max-width: 62ch; }
.hero-cta { margin-top: 30px; display: flex; align-items: center; gap: 18px; flex-wrap: wrap; }
.hero-note { font-size: 13px; color: var(--ink-mute); }

/* Hero 右侧视觉容器 */
.hero-visual { position: relative; }
.hero-visual svg { width: 100%; height: auto; display: block; filter: drop-shadow(0 18px 40px rgba(3, 8, 18, 0.6)); }

/* 数据流动画：虚线沿路径流动 */
.flow { stroke-dasharray: 7 9; animation: flow 1.5s linear infinite; }
.flow.slow { animation-duration: 2.4s; }
.flow.rev { animation-direction: reverse; }
@keyframes flow { to { stroke-dashoffset: -32; } }

/* 节点呼吸 */
.blip { animation: blip 2.8s ease-in-out infinite; transform-origin: center; }
.blip.d1 { animation-delay: 0.5s; }
.blip.d2 { animation-delay: 1.1s; }
.blip.d3 { animation-delay: 1.7s; }
@keyframes blip { 0%, 100% { opacity: 0.35; } 50% { opacity: 1; } }

/* 扫描线 */
.scan { animation: scan 4.2s cubic-bezier(0.5, 0, 0.5, 1) infinite; }
@keyframes scan { 0% { transform: translateY(0); opacity: 0; } 12% { opacity: 1; } 88% { opacity: 1; } 100% { transform: translateY(186px); opacity: 0; } }

/* ---------- 统计条 ---------- */
.stats {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1px; margin-top: 44px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.stat { background: rgba(11, 18, 32, 0.72); padding: 18px 20px; }
.stat b {
  display: block; font-size: 25px; font-weight: 750; letter-spacing: -0.02em;
  background: linear-gradient(92deg, #7dd3fc, #a5b4fc);
  -webkit-background-clip: text; background-clip: text;
  color: transparent; -webkit-text-fill-color: transparent;
}
.stat span { font-size: 12.5px; color: var(--ink-mute); }

/* ---------- 按钮 ---------- */
.btn-primary {
  display: inline-block; position: relative;
  background: linear-gradient(96deg, #38bdf8, #6366f1);
  color: #06101f;
  padding: 14px 26px; border-radius: 10px; text-decoration: none;
  font-size: 16px; font-weight: 700; border: none; cursor: pointer;
  box-shadow: 0 8px 24px -8px rgba(56, 189, 248, 0.55);
  transition: transform 0.16s ease, box-shadow 0.16s ease, filter 0.16s ease;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 32px -8px rgba(56, 189, 248, 0.7); filter: saturate(115%); }
.btn-primary:active { transform: translateY(0); }
.btn-primary:disabled { background: #2a3650; color: #7d8aa3; box-shadow: none; cursor: not-allowed; transform: none; }
.btn-primary.full { width: 100%; }

/* 键盘可达性：所有可聚焦元素保留清晰焦点环 */
a:focus-visible, button:focus-visible, input:focus-visible,
select:focus-visible, textarea:focus-visible {
  outline: 3px solid #7dd3fc; outline-offset: 3px;
}

/* ---------- 区块 ---------- */
.section { padding: 68px 0; position: relative; }
.section.alt {
  background: linear-gradient(180deg, rgba(15, 26, 46, 0.55), rgba(9, 15, 28, 0.55));
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.section-lede { font-size: 16px; color: var(--ink-soft); max-width: 70ch; }

/* 小标题上方的装饰线 */
.section h2 { position: relative; }
.rule {
  width: 54px; height: 3px; border-radius: 3px; margin-bottom: 18px;
  background: linear-gradient(90deg, var(--brand), var(--brand-2));
  box-shadow: 0 0 16px var(--glow);
}

.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(268px, 1fr)); gap: 20px; margin-top: 26px; }

/* 玻璃卡片 + 悬停时的边缘高光 */
.card {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
  overflow: hidden;
}
.card::before {
  content: "";
  position: absolute; inset: 0 0 auto 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(56, 189, 248, 0.55), transparent);
  opacity: 0; transition: opacity 0.24s ease;
}
.card:hover {
  transform: translateY(-3px);
  border-color: var(--line-strong);
  box-shadow: 0 18px 40px -22px rgba(0, 0, 0, 0.9), 0 0 0 1px rgba(56, 189, 248, 0.10);
}
.card:hover::before { opacity: 1; }
.card p { margin: 0; font-size: 15px; color: var(--ink-soft); }

/* 卡片图标 */
.ico {
  width: 42px; height: 42px; border-radius: 11px; margin-bottom: 14px;
  display: grid; place-items: center;
  background: rgba(56, 189, 248, 0.10);
  border: 1px solid rgba(56, 189, 248, 0.24);
}
.ico svg { display: block; }

.list { margin: 22px 0; padding: 0; list-style: none; }
.list li {
  position: relative; margin-bottom: 14px; padding-left: 28px; color: var(--ink-soft);
}
.list li::before {
  content: "";
  position: absolute; left: 4px; top: 11px;
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--brand);
  box-shadow: 0 0 10px var(--glow);
}
.list b { color: var(--ink); font-weight: 650; }

/* ---------- 工具包卡片 ---------- */
.toolkit { display: flex; flex-direction: column; }
.toolkit-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 10px; }
.toolkit-head h3 { margin: 0 0 10px; }

/* ---------- 实战笔记卡片 ---------- */
/* 整张卡片是 <a>，所以要显式取消下划线并让它按列排版 */
a.card.note {
  display: flex; flex-direction: column;
  text-decoration: none; color: inherit;
}
a.card.note:hover {
  transform: translateY(-2px);
  border-color: var(--brand);
  box-shadow: 0 10px 30px rgba(56, 189, 248, 0.10);
}
a.card.note h3 { margin: 0 0 10px; font-size: 17px; line-height: 1.45; }
a.card.note p {
  margin: 0 0 16px; font-size: 14px; line-height: 1.7; color: var(--ink-mute);
  /* 摘要长短不一，截到三行让一排卡片高度齐平 */
  display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical;
  overflow: hidden;
}
.note-foot {
  margin-top: auto; display: flex; align-items: center;
  justify-content: space-between; gap: 10px; flex-wrap: wrap;
}
.note-tags { display: inline-flex; gap: 6px; flex-wrap: wrap; }
.note-tags .tag {
  background: rgba(56, 189, 248, 0.09); color: #8fc9e8; font-weight: 600;
}
.note-date { font-size: 12px; color: #5f6d7e; white-space: nowrap; }
.notes-more { margin-top: 24px; }
.notes-more .btn-ghost { display: inline-block; text-decoration: none; }
.tag {
  flex: none; font-size: 11.5px; font-weight: 700; padding: 4px 10px;
  border-radius: 999px; white-space: nowrap; letter-spacing: 0.02em;
}
.tag-ready { background: rgba(74, 222, 128, 0.14); color: #6ee7a0; border: 1px solid rgba(74, 222, 128, 0.3); }
.tag-building { background: rgba(148, 163, 184, 0.12); color: #9aa8be; border: 1px solid rgba(148, 163, 184, 0.24); }
.toolkit-detail { margin: 12px 0 18px; padding-left: 20px; font-size: 14px; color: var(--ink-soft); }
.toolkit-detail li { margin-bottom: 6px; }
.toolkit .btn-ghost { margin-top: auto; }
.btn-ghost {
  background: rgba(56, 189, 248, 0.07); color: #9ad9f7;
  border: 1px solid var(--line-strong);
  padding: 10px 17px; border-radius: 9px; font: inherit; font-size: 14px;
  font-weight: 650; cursor: pointer; align-self: flex-start;
  transition: background 0.16s ease, color 0.16s ease, border-color 0.16s ease;
}
.btn-ghost:hover { background: rgba(56, 189, 248, 0.18); color: #d8f2ff; border-color: var(--brand); }

.picked {
  background: rgba(56, 189, 248, 0.10);
  border: 1px solid rgba(56, 189, 248, 0.30);
  border-radius: 10px;
  padding: 12px 15px; font-size: 14px; font-weight: 650; color: #a5ddf8;
}

.download-slot { margin-top: 18px; display: flex; flex-direction: column; gap: 9px; align-items: flex-start; }
.download-slot .hint { margin: 0; }

/* ---------- 表单 ---------- */
.form-shell {
  margin-top: 26px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 30px;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 30px 70px -40px rgba(0, 0, 0, 0.95);
}
form { margin-top: 0; }
.field { margin-bottom: 20px; }
.field > label { display: block; font-size: 14px; font-weight: 650; margin-bottom: 8px; color: var(--ink); }
.req { color: var(--err); }

input[type="text"], select, textarea {
  width: 100%; padding: 12px 14px; font: inherit; font-size: 15px;
  color: var(--ink); background: rgba(7, 12, 22, 0.72);
  border: 1px solid rgba(126, 160, 214, 0.24); border-radius: 10px;
  transition: border-color 0.16s ease, box-shadow 0.16s ease, background 0.16s ease;
}
input[type="text"]::placeholder, textarea::placeholder { color: #64748b; }
input[type="text"]:hover, select:hover, textarea:hover { border-color: rgba(126, 160, 214, 0.4); }
input[type="text"]:focus, select:focus, textarea:focus {
  border-color: var(--brand);
  box-shadow: 0 0 0 4px rgba(56, 189, 248, 0.12);
  background: rgba(9, 16, 28, 0.9);
}
select option { background: var(--panel-solid); color: var(--ink); }
textarea { resize: vertical; }
input[aria-invalid="true"], textarea[aria-invalid="true"] { border-color: var(--err); }

.hint { font-size: 13px; color: var(--ink-mute); margin: 7px 0 0; }
.err { font-size: 13px; color: var(--err); margin: 7px 0 0; min-height: 0; }

.field.checkbox {
  display: grid; grid-template-columns: auto 1fr; gap: 11px; align-items: start;
}
.field.checkbox input { width: 18px; height: 18px; margin-top: 4px; accent-color: var(--brand); }
.field.checkbox label { font-size: 14px; font-weight: 400; color: var(--ink-soft); margin: 0; }
.field.checkbox .err { grid-column: 2; }

/* 蜜罐：对视觉与读屏用户都隐藏，但机器人仍会填 */
.trap { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }

.form-msg { margin-top: 15px; font-size: 15px; min-height: 24px; }
.form-msg.ok { color: var(--ok); font-weight: 650; }
.form-msg.bad { color: var(--err); }

/* ---------- FAQ ---------- */
.faq { margin: 26px 0 0; }
.faq dt {
  font-weight: 650; margin-top: 22px; color: var(--ink);
  padding-left: 20px; position: relative;
}
.faq dt::before {
  content: "";
  position: absolute; left: 0; top: 10px;
  width: 9px; height: 9px; border-radius: 2px;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
}
.faq dd { margin: 7px 0 0 20px; color: var(--ink-soft); }

/* ---------- 页脚 ---------- */
.footer {
  padding: 38px 0 46px;
  border-top: 1px solid var(--line);
  background: rgba(5, 9, 17, 0.6);
}
.footer p { margin: 0 0 7px; }

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; gap: 34px; }
  .hero-visual { order: -1; max-width: 520px; }
}
@media (max-width: 600px) {
  .hero { padding: 50px 0 46px; }
  .section { padding: 46px 0; }
  .form-shell { padding: 20px; border-radius: 14px; }
  body::after { background-size: 34px 34px; }
}

/* 尊重减少动效偏好：关掉所有流动与呼吸 */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; animation: none !important; }
}