/* ROOT: sticky teal mast, split hero, 3-col cards, horizontal steps, table, 2x2 scenes */
:root {
  --teal: #128C7E;
  --teal-deep: #0B5C54;
  --mint: #25D366;
  --mint-soft: #E8F8EE;
  --ink: #12221F;
  --muted: #4A5F5A;
  --line: #D5E8E3;
  --paper: #FFFFFF;
  --sand: #F4FAF7;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.7;
}

img,
svg {
  max-width: 100%;
}

a {
  color: var(--teal);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.mast {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 12px 32px;
  background: var(--teal);
  color: #fff;
  box-shadow: 0 2px 10px rgba(11, 92, 84, 0.18);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-weight: 700;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.brand:hover {
  text-decoration: none;
  color: #fff;
}

.brand svg {
  flex-shrink: 0;
}

.jump {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  justify-content: flex-end;
}

.jump a {
  color: #fff;
  font-size: 13px;
}

.jump a:hover {
  color: var(--mint);
  text-decoration: none;
}

.wrap {
  width: min(1180px, calc(100% - 48px));
  margin: 0 auto;
}

.hero {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 40px;
  align-items: center;
  padding: 56px 0 40px;
}

.hero h1 {
  margin: 0 0 16px;
  font-size: 32px;
  line-height: 1.35;
  color: var(--teal-deep);
}

.hero p {
  margin: 0 0 12px;
  color: var(--muted);
  font-size: 16px;
}

.meta-line {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 20px;
  font-size: 13px;
  color: var(--muted);
}

.demo-card {
  background: linear-gradient(160deg, var(--teal) 0%, #0E6B60 100%);
  color: #fff;
  border-radius: 18px;
  padding: 28px;
  min-height: 280px;
  box-shadow: 0 16px 40px rgba(18, 140, 126, 0.25);
}

.demo-card h3 {
  margin: 0 0 8px;
  font-size: 18px;
}

.demo-card p {
  margin: 0 0 16px;
  color: #E7FFF4;
  font-size: 14px;
}

.demo-row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 12px;
  padding: 12px 14px;
  margin-bottom: 10px;
  font-size: 13px;
}

.slab {
  padding: 48px 0;
}

.slab.alt {
  background: var(--sand);
}

.slab h2 {
  margin: 0 0 12px;
  font-size: 26px;
  color: var(--teal-deep);
}

.lead {
  margin: 0 0 28px;
  max-width: 720px;
  color: var(--muted);
}

.trio {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.tile {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 22px 20px;
}

.tile svg {
  display: block;
  margin-bottom: 12px;
}

.tile h3 {
  margin: 0 0 8px;
  font-size: 17px;
  color: var(--teal-deep);
}

.tile p {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 14px;
}

.tile p:last-child {
  margin-bottom: 0;
}

.stride {
  display: flex;
  gap: 0;
  margin-top: 8px;
}

.stride-item {
  flex: 1;
  position: relative;
  padding: 20px 16px 16px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-left: none;
}

.stride-item:first-child {
  border-left: 1px solid var(--line);
  border-radius: 12px 0 0 12px;
}

.stride-item:last-child {
  border-radius: 0 12px 12px 0;
}

.stride-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--mint);
  color: #07351F;
  font-weight: 700;
  font-size: 13px;
  margin-bottom: 8px;
}

.stride-item h3 {
  margin: 0 0 8px;
  font-size: 16px;
}

.stride-item p {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
}

.sheet {
  width: 100%;
  border-collapse: collapse;
  background: var(--paper);
  border: 1px solid var(--line);
}

.sheet th,
.sheet td {
  border-bottom: 1px solid var(--line);
  padding: 14px 16px;
  text-align: left;
  vertical-align: top;
  font-size: 14px;
}

.sheet th {
  background: var(--teal);
  color: #fff;
  font-weight: 600;
}

.sheet tr:last-child td {
  border-bottom: none;
}

.sheet td:first-child {
  font-weight: 600;
  color: var(--teal-deep);
  width: 22%;
}

.quad {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.scene {
  background: var(--paper);
  border-radius: 14px;
  padding: 22px;
  border-top: 4px solid var(--mint);
  box-shadow: 0 6px 20px rgba(18, 140, 126, 0.06);
}

.scene h3 {
  margin: 0 0 10px;
  font-size: 17px;
}

.scene p {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 14px;
}

.bias {
  display: grid;
  gap: 14px;
}

.bias-card {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 16px;
  align-items: start;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 18px;
}

.bias-card h3 {
  margin: 0 0 8px;
  font-size: 16px;
}

.bias-card p {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 14px;
}

.faq-block details {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0 18px;
  margin-bottom: 10px;
}

.faq-block summary {
  cursor: pointer;
  padding: 14px 0;
  font-weight: 600;
  color: var(--teal-deep);
}

.faq-block details p {
  margin: 0 0 14px;
  color: var(--muted);
  font-size: 14px;
}

.colophon {
  background: var(--teal-deep);
  color: #D7EEEA;
  padding: 36px 0 28px;
}

.colophon h2,
.colophon .foot-k {
  color: #fff;
  font-size: 16px;
  margin: 0 0 8px;
  font-weight: 700;
}

.foot-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-bottom: 20px;
}

.colophon p {
  margin: 0 0 8px;
  font-size: 13px;
}

.legal {
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  padding-top: 16px;
  font-size: 12px;
}

@media (max-width: 900px) {
  .mast {
    flex-direction: column;
    align-items: flex-start;
    padding: 12px 16px;
  }

  .hero,
  .trio,
  .quad,
  .foot-grid,
  .bias-card {
    grid-template-columns: 1fr;
  }

  .stride {
    flex-direction: column;
  }

  .stride-item,
  .stride-item:first-child,
  .stride-item:last-child {
    border: 1px solid var(--line);
    border-radius: 12px;
    margin-bottom: 10px;
  }

  .wrap {
    width: calc(100% - 32px);
  }
}