/* ===== AI 智能对话工作台 · 静态官网样式 ===== */
/* Soft UI · 低饱和靛蓝 · 大圆角 · 柔和阴影 · 灰度配色 */

:root {
  --bg: #fbfbfd;
  --surface: #ffffff;
  --surface-2: #f4f5f9;
  --ink: #1d2433;
  --ink-2: #5a6275;
  --ink-3: #8c93a5;
  --accent: #4c5fd5;
  --accent-soft: #eef0fb;
  --accent-ink: #3a4bb0;
  --line: #ecedf2;
  --radius: 18px;
  --radius-lg: 26px;
  --shadow-sm: 0 4px 14px rgba(29, 36, 51, 0.05);
  --shadow: 0 14px 40px rgba(29, 36, 51, 0.07);
  --shadow-lg: 0 30px 70px rgba(29, 36, 51, 0.10);
  --maxw: 1120px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration: none; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ===== 导航 ===== */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(251, 251, 253, 0.82);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
}
.nav-inner {
  max-width: var(--maxw); margin: 0 auto; padding: 16px 24px;
  display: flex; align-items: center; justify-content: space-between;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; letter-spacing: -0.01em; }
.brand .logo {
  width: 34px; height: 34px; border-radius: 11px;
  background: var(--accent); display: grid; place-items: center;
  box-shadow: var(--shadow-sm);
}
.brand .logo svg { width: 18px; height: 18px; color: #fff; }
.nav-links { display: flex; align-items: center; gap: 30px; }
.nav-links a { color: var(--ink-2); font-size: 15px; font-weight: 500; transition: color .2s; }
.nav-links a:hover { color: var(--ink); }
.nav-cta { display: flex; align-items: center; gap: 14px; }

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 15px; font-weight: 600; cursor: pointer;
  padding: 11px 20px; border-radius: 12px; border: none;
  transition: transform .15s ease, box-shadow .2s ease, background .2s ease;
  font-family: inherit;
}
.btn-primary { background: var(--accent); color: #fff; box-shadow: 0 8px 20px rgba(76, 95, 213, 0.28); }
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 12px 26px rgba(76, 95, 213, 0.34); }
.btn-ghost { background: transparent; color: var(--ink); }
.btn-ghost:hover { background: var(--surface-2); }
.btn-soft { background: var(--accent-soft); color: var(--accent-ink); }
.btn-soft:hover { background: #e4e7f8; }

/* ===== Hero ===== */
.hero { padding: 92px 0 64px; }
.hero-grid { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 56px; align-items: center; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; font-weight: 600; color: var(--accent-ink);
  background: var(--accent-soft); padding: 7px 14px; border-radius: 999px;
  letter-spacing: 0.02em;
}
.eyebrow .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--accent); }
.hero h1 {
  font-size: 50px; line-height: 1.12; letter-spacing: -0.03em;
  margin: 22px 0 18px; font-weight: 760;
}
.hero h1 .grad { color: var(--accent); }
.hero p.lead { font-size: 18px; color: var(--ink-2); max-width: 480px; }
.hero-actions { display: flex; gap: 14px; margin-top: 30px; }
.hero-note { margin-top: 18px; font-size: 13.5px; color: var(--ink-3); display: flex; align-items: center; gap: 8px; }
.hero-note svg { width: 16px; height: 16px; color: var(--accent); }

/* 产品预览 mockup */
.preview {
  background: var(--surface); border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg); padding: 18px; position: relative; overflow: hidden;
}
.preview::before {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(120% 90% at 100% 0%, var(--accent-soft) 0%, transparent 46%);
  pointer-events: none;
}
.pv-bar { display: flex; gap: 7px; padding: 4px 6px 14px; }
.pv-bar i { width: 11px; height: 11px; border-radius: 50%; background: var(--surface-2); display: block; }
.pv-bar i:nth-child(1){ background: #ffd2cf; } .pv-bar i:nth-child(2){ background: #ffe6bf; } .pv-bar i:nth-child(3){ background: #cfeede; }
.pv-body { display: flex; flex-direction: column; gap: 14px; position: relative; }
.bubble { display: flex; gap: 12px; align-items: flex-start; }
.bubble .av { width: 34px; height: 34px; border-radius: 10px; flex: none; display: grid; place-items: center; font-size: 13px; font-weight: 700; }
.bubble.user .av { background: var(--surface-2); color: var(--ink-2); }
.bubble.ai .av { background: var(--accent); color: #fff; }
.bubble .txt { background: var(--surface-2); border-radius: 14px; padding: 12px 15px; font-size: 14.5px; color: var(--ink); max-width: 380px; }
.bubble.ai .txt { background: var(--accent-soft); color: var(--ink); }
.bubble .txt .sub { display: block; font-size: 12px; color: var(--ink-3); margin-top: 6px; }
.pv-input {
  margin-top: 6px; display: flex; align-items: center; gap: 10px;
  background: var(--surface-2); border-radius: 14px; padding: 13px 15px;
}
.pv-input span { font-size: 14px; color: var(--ink-3); flex: 1; }
.pv-input .send { width: 32px; height: 32px; border-radius: 9px; background: var(--accent); display: grid; place-items: center; }
.pv-input .send svg { width: 16px; height: 16px; color: #fff; }

/* ===== 信任条 ===== */
.trust { padding: 8px 0 56px; }
.trust-row { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; }
.trust-item {
  display: flex; align-items: center; gap: 10px;
  background: var(--surface); border-radius: 14px; padding: 14px 20px;
  box-shadow: var(--shadow-sm); font-size: 14.5px; color: var(--ink-2); font-weight: 500;
}
.trust-item b { color: var(--ink); font-weight: 720; font-size: 17px; }

/* ===== 通用区块 ===== */
.section { padding: 76px 0; }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 52px; }
.section-head .eyebrow { margin-bottom: 16px; }
.section-head h2 { font-size: 36px; letter-spacing: -0.02em; font-weight: 740; }
.section-head p { color: var(--ink-2); font-size: 17px; margin-top: 14px; }

/* 能力卡 */
.feat-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.card {
  background: var(--surface); border-radius: var(--radius); padding: 28px;
  box-shadow: var(--shadow-sm); transition: transform .2s ease, box-shadow .25s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.card .ic {
  width: 48px; height: 48px; border-radius: 14px; background: var(--accent-soft);
  display: grid; place-items: center; margin-bottom: 18px;
}
.card .ic svg { width: 24px; height: 24px; color: var(--accent); }
.card h3 { font-size: 19px; letter-spacing: -0.01em; font-weight: 680; }
.card p { color: var(--ink-2); font-size: 15px; margin-top: 9px; }

/* 工作流 */
.flow { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.step {
  background: var(--surface); border-radius: var(--radius); padding: 30px 28px;
  box-shadow: var(--shadow-sm); position: relative;
}
.step .num {
  width: 40px; height: 40px; border-radius: 12px; background: var(--accent);
  color: #fff; font-weight: 720; font-size: 17px; display: grid; place-items: center;
  margin-bottom: 18px; box-shadow: 0 8px 18px rgba(76,95,213,.26);
}
.step h3 { font-size: 18px; font-weight: 680; }
.step p { color: var(--ink-2); font-size: 15px; margin-top: 8px; }

/* 指标 */
.metrics { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.metric { text-align: center; background: var(--surface); border-radius: var(--radius); padding: 32px 20px; box-shadow: var(--shadow-sm); }
.metric .v { font-size: 42px; font-weight: 760; letter-spacing: -0.02em; color: var(--accent); }
.metric .k { color: var(--ink-2); font-size: 15px; margin-top: 6px; }

/* CTA */
.cta-band {
  background: linear-gradient(180deg, var(--surface) 0%, var(--accent-soft) 100%);
  border-radius: var(--radius-lg); padding: 64px 40px; text-align: center;
  box-shadow: var(--shadow); margin: 20px auto 0;
}
.cta-band h2 { font-size: 34px; letter-spacing: -0.02em; font-weight: 740; }
.cta-band p { color: var(--ink-2); font-size: 17px; margin: 14px auto 30px; max-width: 480px; }
.cta-actions { display: flex; gap: 14px; justify-content: center; }

/* 页脚 */
.footer { padding: 56px 0 40px; margin-top: 40px; }
.footer-inner { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 30px; }
.footer .brand { font-size: 17px; }
.footer-cols { display: flex; gap: 64px; flex-wrap: wrap; }
.footer-col h4 { font-size: 14px; color: var(--ink-3); font-weight: 600; margin-bottom: 14px; letter-spacing: .03em; }
.footer-col a { display: block; color: var(--ink-2); font-size: 14.5px; margin-bottom: 10px; transition: color .2s; }
.footer-col a:hover { color: var(--accent); }
.footer-bottom { margin-top: 40px; padding-top: 24px; border-top: 1px solid var(--line); color: var(--ink-3); font-size: 13.5px; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; }

/* ===== 二级页面：功能详情 ===== */
.subhero { padding: 64px 0 36px; }
.subhero h1 { font-size: 42px; letter-spacing: -0.03em; font-weight: 760; max-width: 720px; }
.subhero p { color: var(--ink-2); font-size: 18px; margin-top: 16px; max-width: 600px; }

.detail { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; padding: 38px 0; }
.detail.flip .d-visual { order: 2; }
.detail .d-text h3 { font-size: 26px; letter-spacing: -0.02em; font-weight: 720; }
.detail .d-text p { color: var(--ink-2); font-size: 16px; margin-top: 14px; }
.detail .d-list { margin-top: 18px; display: flex; flex-direction: column; gap: 12px; }
.detail .d-list li { list-style: none; display: flex; gap: 11px; align-items: flex-start; font-size: 15.5px; color: var(--ink); }
.detail .d-list svg { width: 20px; height: 20px; color: var(--accent); flex: none; margin-top: 2px; }
.detail .d-visual {
  background: var(--surface); border-radius: var(--radius-lg); padding: 22px;
  box-shadow: var(--shadow); min-height: 260px; display: flex; flex-direction: column; gap: 12px; justify-content: center;
}
.chip-row { display: flex; flex-wrap: wrap; gap: 10px; }
.chip { background: var(--accent-soft); color: var(--accent-ink); font-size: 13.5px; font-weight: 600; padding: 8px 14px; border-radius: 999px; }
.panel-row { display: flex; align-items: center; gap: 12px; background: var(--surface-2); border-radius: 13px; padding: 13px 15px; }
.panel-row .ic { width: 30px; height: 30px; border-radius: 9px; background: var(--accent); display: grid; place-items: center; flex: none; }
.panel-row .ic svg { width: 16px; height: 16px; color: #fff; }
.panel-row .t { font-size: 14.5px; font-weight: 600; }
.panel-row .s { font-size: 12.5px; color: var(--ink-3); }
.bar { height: 10px; border-radius: 999px; background: var(--surface-2); overflow: hidden; }
.bar > i { display: block; height: 100%; border-radius: 999px; background: var(--accent); }

.back-link { display: inline-flex; align-items: center; gap: 7px; color: var(--ink-2); font-size: 14.5px; font-weight: 500; margin-bottom: 8px; transition: color .2s; }
.back-link:hover { color: var(--accent); }
.back-link svg { width: 16px; height: 16px; }

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .hero-grid, .detail { grid-template-columns: 1fr; gap: 36px; }
  .detail.flip .d-visual { order: 0; }
  .feat-grid, .flow, .metrics { grid-template-columns: 1fr; }
  .metrics { grid-template-columns: 1fr 1fr; }
  .nav-links { display: none; }
  .hero h1 { font-size: 38px; }
  .section-head h2, .subhero h1 { font-size: 30px; }
  .price-grid { grid-template-columns: 1fr; gap: 28px; }
  .price-desc { min-height: auto; }
}

/* Pricing */
.pricing { background: var(--bg); }
.price-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; align-items: stretch; }
.price-card { background: var(--card); border-radius: var(--radius-lg); padding: 36px 30px 32px; box-shadow: var(--shadow); display: flex; flex-direction: column; position: relative; }
.price-card.featured { box-shadow: 0 24px 60px rgba(76,95,213,.18); }
.price-tag { position: absolute; top: -13px; left: 50%; transform: translateX(-50%); background: var(--accent); color: #fff; font-size: 12px; font-weight: 600; padding: 6px 15px; border-radius: 999px; letter-spacing: .04em; white-space: nowrap; }
.price-name { font-size: 18px; font-weight: 600; }
.price-desc { color: var(--ink-3); font-size: 14px; margin-top: 6px; min-height: 42px; }
.price-num { margin: 18px 0 2px; font-size: 42px; font-weight: 700; letter-spacing: -.02em; line-height: 1; }
.price-num small { font-size: 15px; font-weight: 500; color: var(--ink-3); }
.price-unit { color: var(--ink-3); font-size: 13px; margin-bottom: 22px; }
.price-list { list-style: none; display: flex; flex-direction: column; gap: 13px; margin: 0 0 28px; flex: 1; }
.price-list li { display: flex; gap: 10px; align-items: flex-start; font-size: 14px; color: var(--ink-2); }
.price-list li svg { width: 17px; height: 17px; color: var(--accent); flex: none; margin-top: 2px; }
.price-list li.off { color: var(--ink-4); }
.price-list li.off svg { color: var(--line-strong); }
.price-btn { width: 100%; }