/* Nova AI 官网 · 全局样式
 * 浅色系 · Stripe / Linear 风格
 * 配色：白底 / 极浅蓝灰 + 深蓝 #1E3A5F + 天蓝 #0EA5E9 + 金 #D4A574
 */

:root {
  --brand-deep: #1E3A5F;
  --brand-blue: #0EA5E9;
  --brand-gold: #D4A574;
  --ink-900: #0F172A;
  --ink-700: #334155;
  --ink-500: #64748B;
  --ink-400: #94A3B8;
  --ink-300: #CBD5E1;
  --bg: #FFFFFF;
  --bg-soft: #F8FAFC;
  --bg-blue: #F0F9FF;
  --border: #E2E8F0;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 12px 40px rgba(15, 23, 42, 0.10);
  --radius: 12px;
  --radius-lg: 20px;
  --max: 1200px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: var(--font);
  color: var(--ink-900);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
a { color: inherit; text-decoration: none; transition: color .2s; }
a:hover { color: var(--brand-blue); }
img { max-width: 100%; display: block; }
h1, h2, h3, h4 { margin: 0; color: var(--ink-900); letter-spacing: -0.01em; line-height: 1.25; }
p { margin: 0; }
.container { max-width: var(--max); margin: 0 auto; padding: 0 24px; }

/* ====== 顶部导航 ====== */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: 18px; color: var(--brand-deep);
}
.brand-mark {
  width: 32px; height: 32px; border-radius: 8px;
  background: linear-gradient(135deg, var(--brand-blue) 0%, var(--brand-deep) 100%);
  position: relative;
  box-shadow: 0 4px 14px rgba(14, 165, 233, 0.35);
}
.brand-mark::after {
  content: ""; position: absolute; inset: 6px;
  border: 2px solid #fff; border-radius: 50%;
  border-top-color: transparent; border-right-color: transparent;
  transform: rotate(-15deg);
}
.nav-links { display: flex; gap: 28px; }
.nav-links a {
  font-size: 14px; color: var(--ink-700); font-weight: 500;
}
.nav-cta {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 9px 18px; border-radius: 8px; font-size: 14px; font-weight: 600;
  background: var(--brand-deep); color: #fff !important;
  transition: all .2s;
}
.nav-cta:hover { background: var(--brand-blue); transform: translateY(-1px); }
@media (max-width: 768px) { .nav-links { display: none; } }

/* ====== Hero ====== */
.hero {
  padding: 80px 0 100px;
  background: linear-gradient(180deg, var(--bg-soft) 0%, var(--bg) 60%);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: ""; position: absolute; top: -200px; right: -200px;
  width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(14, 165, 233, 0.12) 0%, transparent 70%);
  pointer-events: none;
}
.hero-grid {
  display: grid; grid-template-columns: 1.05fr 1fr;
  gap: 60px; align-items: center; position: relative;
}
.hero-tag {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 14px; border-radius: 100px;
  background: var(--bg-blue); color: var(--brand-blue);
  font-size: 13px; font-weight: 600; border: 1px solid #BAE6FD;
  margin-bottom: 24px;
}
.hero-tag .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--brand-blue); box-shadow: 0 0 0 4px rgba(14, 165, 233, 0.2); }
.hero h1 {
  font-size: 56px; font-weight: 700; letter-spacing: -0.02em;
  line-height: 1.1; margin-bottom: 20px;
}
.hero h1 .accent { background: linear-gradient(135deg, var(--brand-blue) 0%, var(--brand-deep) 100%); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-sub {
  font-size: 19px; color: var(--ink-700);
  margin-bottom: 16px;
}
.hero-desc {
  font-size: 15px; color: var(--ink-500);
  margin-bottom: 36px; max-width: 540px;
}
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 14px 26px; border-radius: 10px;
  font-size: 15px; font-weight: 600; cursor: pointer;
  transition: all .2s; border: 1px solid transparent;
}
.btn-primary { background: var(--brand-deep); color: #fff; box-shadow: 0 4px 14px rgba(30, 58, 95, 0.25); }
.btn-primary:hover { background: var(--brand-blue); color: #fff; transform: translateY(-2px); box-shadow: 0 8px 24px rgba(14, 165, 233, 0.35); }
.btn-ghost { background: #fff; color: var(--ink-900); border-color: var(--border); }
.btn-ghost:hover { border-color: var(--brand-blue); color: var(--brand-blue); }
.hero-trust {
  display: flex; gap: 28px; margin-top: 48px; padding-top: 28px;
  border-top: 1px solid var(--border); flex-wrap: wrap;
}
.hero-trust-item { display: flex; align-items: center; gap: 8px; font-size: 13px; color: var(--ink-500); }
.hero-trust-item .check {
  width: 18px; height: 18px; border-radius: 50%; background: var(--bg-blue); color: var(--brand-blue);
  display: flex; align-items: center; justify-content: center; font-size: 11px; font-weight: bold;
}
.hero-img {
  position: relative; border-radius: var(--radius-lg);
  overflow: hidden; box-shadow: var(--shadow-lg);
  background: linear-gradient(135deg, #0F1B2E 0%, #1E3A5F 100%);
  aspect-ratio: 4/3;
}
.hero-img img { width: 100%; height: 100%; object-fit: cover; }
.hero-img::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(14, 165, 233, 0.10) 0%, transparent 50%);
  pointer-events: none;
}
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .hero h1 { font-size: 38px; }
  .hero-sub { font-size: 17px; }
}

/* ====== Section 通用 ====== */
.section { padding: 96px 0; }
.section-soft { background: var(--bg-soft); }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 56px; }
.section-eyebrow {
  display: inline-block; font-size: 13px; font-weight: 600;
  color: var(--brand-blue); text-transform: uppercase; letter-spacing: 0.08em;
  margin-bottom: 14px;
}
.section h2 { font-size: 40px; font-weight: 700; margin-bottom: 16px; }
.section-head p { font-size: 17px; color: var(--ink-500); }
@media (max-width: 768px) { .section { padding: 64px 0; } .section h2 { font-size: 30px; } }

/* ====== 优势卡片 ====== */
.advantages { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.adv-card {
  padding: 36px 32px; border-radius: var(--radius-lg);
  background: #fff; border: 1px solid var(--border);
  transition: all .3s; position: relative; overflow: hidden;
}
.adv-card::before {
  content: ""; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: linear-gradient(90deg, var(--brand-blue), var(--brand-gold));
  transform: scaleX(0); transform-origin: left; transition: transform .3s;
}
.adv-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: transparent; }
.adv-card:hover::before { transform: scaleX(1); }
.adv-icon {
  width: 48px; height: 48px; border-radius: 12px;
  background: var(--bg-blue); color: var(--brand-blue);
  display: flex; align-items: center; justify-content: center;
  font-size: 22px; font-weight: 700; margin-bottom: 22px;
}
.adv-card h3 { font-size: 22px; font-weight: 600; margin-bottom: 12px; }
.adv-card p { color: var(--ink-500); font-size: 15px; }
.adv-card ul { margin: 16px 0 0; padding: 0; list-style: none; }
.adv-card li {
  padding: 6px 0 6px 22px; position: relative;
  font-size: 14px; color: var(--ink-700);
}
.adv-card li::before {
  content: "✓"; position: absolute; left: 0;
  color: var(--brand-blue); font-weight: bold;
}
@media (max-width: 900px) { .advantages { grid-template-columns: 1fr; } }

/* ====== 技术架构 ====== */
.arch-stack {
  max-width: 900px; margin: 0 auto;
  border-radius: var(--radius-lg); overflow: hidden;
  background: #fff; border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}
.arch-layer {
  padding: 24px 32px; border-bottom: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 12px;
}
.arch-layer:last-child { border-bottom: 0; }
.arch-label {
  display: inline-block; padding: 4px 12px; border-radius: 6px;
  background: var(--brand-deep); color: #fff;
  font-size: 12px; font-weight: 600;
}
.arch-items { display: flex; gap: 10px; flex-wrap: wrap; }
.arch-item {
  padding: 6px 14px; border-radius: 6px;
  background: var(--bg-soft); color: var(--ink-700);
  font-size: 13px; font-weight: 500; border: 1px solid var(--border);
}

/* ====== 多渠道 ====== */
.channels { display: grid; grid-template-columns: repeat(5, 1fr); gap: 16px; }
.channel {
  padding: 28px 20px; border-radius: var(--radius);
  background: #fff; border: 1px solid var(--border);
  text-align: center; transition: all .25s;
}
.channel:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); border-color: var(--brand-blue); }
.channel-icon { font-size: 32px; margin-bottom: 12px; }
.channel-name { font-size: 14px; font-weight: 600; color: var(--ink-700); }
.channel-desc { font-size: 12px; color: var(--ink-500); margin-top: 4px; }
@media (max-width: 900px) { .channels { grid-template-columns: repeat(2, 1fr); } }

/* ====== 场景卡片 ====== */
.scenarios { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.scenario {
  padding: 32px; border-radius: var(--radius-lg);
  background: #fff; border: 1px solid var(--border);
  position: relative; overflow: hidden;
}
.scenario-tag {
  display: inline-block; padding: 4px 10px; border-radius: 4px;
  background: var(--bg-blue); color: var(--brand-blue);
  font-size: 11px; font-weight: 700; letter-spacing: 0.05em;
  margin-bottom: 18px;
}
.scenario h3 { font-size: 20px; font-weight: 600; margin-bottom: 10px; }
.scenario p { color: var(--ink-500); font-size: 14px; margin-bottom: 18px; }
.scenario-list { list-style: none; padding: 0; margin: 0; }
.scenario-list li {
  padding: 5px 0 5px 18px; position: relative;
  font-size: 13px; color: var(--ink-700);
}
.scenario-list li::before {
  content: "→"; position: absolute; left: 0; color: var(--brand-gold); font-weight: bold;
}
.scenario-meta {
  margin-top: 22px; padding-top: 18px; border-top: 1px dashed var(--border);
  display: flex; justify-content: space-between; font-size: 12px; color: var(--ink-500);
}
.scenario-meta strong { color: var(--brand-deep); font-size: 14px; }
@media (max-width: 900px) { .scenarios { grid-template-columns: 1fr; } }

/* ====== ROI 数据条 ====== */
.roi-strip {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 0;
  border-radius: var(--radius-lg); overflow: hidden;
  background: linear-gradient(135deg, var(--brand-deep) 0%, #0F1B2E 100%);
  color: #fff;
}
.roi-cell {
  padding: 36px 24px; text-align: center;
  border-right: 1px solid rgba(255,255,255,0.1);
}
.roi-cell:last-child { border-right: 0; }
.roi-num {
  font-size: 44px; font-weight: 700;
  background: linear-gradient(135deg, #5EEAD4 0%, var(--brand-gold) 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  letter-spacing: -0.02em;
}
.roi-label { font-size: 13px; color: rgba(255,255,255,0.7); margin-top: 6px; }
@media (max-width: 900px) { .roi-strip { grid-template-columns: repeat(2, 1fr); } }

/* ====== 定价 ====== */
.pricing-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.price-card {
  padding: 32px 26px; border-radius: var(--radius-lg);
  background: #fff; border: 1px solid var(--border);
  transition: all .25s; position: relative;
}
.price-card.featured {
  border: 2px solid var(--brand-blue);
  box-shadow: 0 8px 28px rgba(14, 165, 233, 0.20);
  transform: scale(1.03);
}
.price-card.featured::before {
  content: "推荐"; position: absolute; top: -12px; left: 50%; transform: translateX(-50%);
  padding: 4px 14px; border-radius: 100px; background: var(--brand-blue); color: #fff;
  font-size: 11px; font-weight: 700; letter-spacing: 0.05em;
}
.price-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); }
.price-card.featured:hover { transform: scale(1.03) translateY(-3px); }
.price-name { font-size: 14px; color: var(--ink-500); font-weight: 600; }
.price-amount {
  font-size: 36px; font-weight: 700; color: var(--brand-deep);
  margin: 12px 0 6px; letter-spacing: -0.02em;
}
.price-amount .yuan { font-size: 18px; font-weight: 500; }
.price-amount small { font-size: 14px; color: var(--ink-500); font-weight: 400; }
.price-desc { font-size: 13px; color: var(--ink-500); margin-bottom: 20px; }
.price-features { list-style: none; padding: 0; margin: 0 0 24px; }
.price-features li {
  padding: 7px 0 7px 22px; position: relative;
  font-size: 13px; color: var(--ink-700);
}
.price-features li::before {
  content: "✓"; position: absolute; left: 0; color: var(--brand-blue); font-weight: bold;
}
.price-cta {
  display: block; text-align: center; padding: 11px;
  border-radius: 8px; font-size: 14px; font-weight: 600;
  background: var(--bg-soft); color: var(--brand-deep);
  transition: all .2s;
}
.price-cta:hover { background: var(--brand-deep); color: #fff; }
.price-card.featured .price-cta { background: var(--brand-blue); color: #fff; }
.price-card.featured .price-cta:hover { background: var(--brand-deep); }
@media (max-width: 900px) { .pricing-grid { grid-template-columns: 1fr; } .price-card.featured { transform: none; } .price-card.featured:hover { transform: translateY(-3px); } }

/* ====== 表格（关于页/技术规格） ====== */
.spec-table {
  width: 100%; border-collapse: collapse;
  background: #fff; border-radius: var(--radius);
  overflow: hidden; box-shadow: var(--shadow-sm); border: 1px solid var(--border);
}
.spec-table th, .spec-table td {
  padding: 14px 20px; text-align: left;
  border-bottom: 1px solid var(--border); font-size: 14px;
}
.spec-table th {
  background: var(--bg-soft); font-weight: 600; color: var(--ink-700);
}
.spec-table tr:last-child td { border-bottom: 0; }
.spec-table td:first-child { font-weight: 600; color: var(--ink-700); }

/* ====== CTA banner ====== */
.cta-banner {
  padding: 64px 48px;
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--brand-deep) 0%, var(--brand-blue) 100%);
  color: #fff; text-align: center; position: relative; overflow: hidden;
}
.cta-banner::before {
  content: ""; position: absolute; top: -50%; right: -10%;
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
  pointer-events: none;
}
.cta-banner h2 { font-size: 36px; color: #fff; margin-bottom: 14px; position: relative; }
.cta-banner p { font-size: 16px; color: rgba(255,255,255,0.85); margin-bottom: 32px; position: relative; }
.cta-banner .btn-primary { background: #fff; color: var(--brand-deep); }
.cta-banner .btn-primary:hover { background: var(--brand-gold); color: var(--brand-deep); }

/* ====== 表单（联系页） ====== */
.form-card {
  background: #fff; padding: 40px;
  border-radius: var(--radius-lg); border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}
.form-row { margin-bottom: 20px; }
.form-row label {
  display: block; font-size: 13px; font-weight: 600;
  color: var(--ink-700); margin-bottom: 6px;
}
.form-row input, .form-row select, .form-row textarea {
  width: 100%; padding: 11px 14px;
  border: 1px solid var(--border); border-radius: 8px;
  font-size: 14px; font-family: inherit; color: var(--ink-900);
  background: var(--bg); transition: border-color .2s;
}
.form-row input:focus, .form-row select:focus, .form-row textarea:focus {
  outline: none; border-color: var(--brand-blue);
  box-shadow: 0 0 0 3px rgba(14, 165, 233, 0.1);
}
.form-row textarea { resize: vertical; min-height: 100px; }
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 600px) { .form-grid { grid-template-columns: 1fr; } }
.form-tip {
  margin-top: 16px; padding: 14px; border-radius: 8px;
  background: var(--bg-blue); color: var(--brand-blue);
  font-size: 13px;
}
.form-tip b { color: var(--brand-deep); }

/* ====== 联系信息卡 ====== */
.contact-info { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-bottom: 40px; }
.info-card {
  padding: 28px; border-radius: var(--radius);
  background: #fff; border: 1px solid var(--border); text-align: center;
}
.info-card .icon {
  width: 44px; height: 44px; border-radius: 50%;
  background: var(--bg-blue); color: var(--brand-blue);
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 14px; font-size: 18px;
}
.info-card h4 { font-size: 14px; font-weight: 600; color: var(--ink-700); margin-bottom: 6px; }
.info-card p { font-size: 14px; color: var(--ink-500); }
@media (max-width: 768px) { .contact-info { grid-template-columns: 1fr; } }

/* ====== 关于页时间线 ====== */
.timeline { max-width: 800px; margin: 0 auto; position: relative; }
.timeline::before {
  content: ""; position: absolute; top: 0; bottom: 0; left: 28px;
  width: 2px; background: var(--border);
}
.timeline-item {
  padding: 0 0 32px 80px; position: relative;
}
.timeline-item::before {
  content: ""; position: absolute; left: 20px; top: 4px;
  width: 18px; height: 18px; border-radius: 50%;
  background: var(--brand-blue); border: 4px solid #fff;
  box-shadow: 0 0 0 2px var(--brand-blue);
}
.timeline-date { font-size: 13px; color: var(--brand-blue); font-weight: 600; margin-bottom: 4px; }
.timeline-title { font-size: 18px; font-weight: 600; margin-bottom: 6px; }
.timeline-desc { font-size: 14px; color: var(--ink-500); }

/* ====== 安全认证徽章 ====== */
.badges { display: flex; gap: 16px; flex-wrap: wrap; justify-content: center; }
.badge {
  padding: 10px 20px; border-radius: 100px;
  background: #fff; border: 1px solid var(--border);
  font-size: 13px; font-weight: 600; color: var(--ink-700);
  display: inline-flex; align-items: center; gap: 8px;
}
.badge .check {
  width: 18px; height: 18px; border-radius: 50%; background: var(--brand-blue); color: #fff;
  display: flex; align-items: center; justify-content: center; font-size: 11px;
}

/* ====== 页脚 ====== */
.footer {
  padding: 64px 0 32px;
  background: #0F1B2E; color: rgba(255,255,255,0.7);
}
.footer-grid {
  display: grid; grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px; margin-bottom: 48px;
}
.footer h4 {
  color: #fff; font-size: 14px; font-weight: 600;
  margin-bottom: 16px; letter-spacing: 0.04em;
}
.footer-brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: 18px; color: #fff;
  margin-bottom: 14px;
}
.footer-brand .brand-mark {
  box-shadow: 0 4px 14px rgba(14, 165, 233, 0.35);
}
.footer p { font-size: 13px; line-height: 1.7; }
.footer-links { list-style: none; padding: 0; margin: 0; }
.footer-links li { padding: 5px 0; }
.footer-links a {
  color: rgba(255,255,255,0.6); font-size: 13px;
}
.footer-links a:hover { color: var(--brand-blue); }
.footer-bottom {
  padding-top: 28px; border-top: 1px solid rgba(255,255,255,0.1);
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px;
  font-size: 12px; color: rgba(255,255,255,0.4);
}
.footer-bottom a { color: rgba(255,255,255,0.6); }
.footer-bottom a:hover { color: var(--brand-blue); }
@media (max-width: 900px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 600px) { .footer-grid { grid-template-columns: 1fr; } }