:root {
  --tech-paper: #f5f5f1;
  --tech-ink: #171716;
  --tech-copy: #5d5d58;
  --tech-quiet: #989893;
  --tech-blue: #9bb4c5;
  --tech-rule: rgba(23, 23, 22, 0.12);
}

* { box-sizing: border-box; }

html { background: var(--tech-paper); }

body {
  margin: 0;
  background: var(--tech-paper);
  color: var(--tech-ink);
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, p { margin: 0; }

.page-return {
  position: fixed;
  z-index: 20;
  top: clamp(20px, 3vw, 30px);
  right: clamp(20px, 4vw, 60px);
  width: 42px;
  height: 42px;
  border: 1px solid var(--tech-rule);
  border-radius: 50%;
  background: rgba(245, 245, 241, .8);
  color: var(--tech-ink);
  transition: transform 300ms ease, background-color 300ms ease;
}

.page-return::before,
.page-return::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 14px;
  height: 1px;
  background: currentColor;
}

.page-return::before { transform: translate(-50%, -50%) rotate(45deg); }
.page-return::after { transform: translate(-50%, -50%) rotate(-45deg); }
.page-return:hover { background: #fff; transform: scale(1.04); }
.page-return:focus-visible { outline: 2px solid rgba(23, 23, 22, .55); outline-offset: 3px; }

.tech-page {
  min-height: 100vh;
  overflow: hidden;
  padding: clamp(34px, 5.2vw, 72px) clamp(24px, 5vw, 72px) 0;
}

.tech-intro {
  width: min(100%, 1260px);
  margin: 0 auto;
  text-align: center;
}

.tech-kicker {
  color: var(--tech-quiet);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.1em;
}

.tech-intro h1 {
  margin-top: 24px;
  font-size: clamp(48px, 6.25vw, 86px);
  font-weight: 600;
  line-height: 1.06;
  letter-spacing: -0.075em;
}

.tech-intro-copy {
  width: max-content;
  max-width: 100%;
  margin: 35px auto 0;
  color: var(--tech-copy);
  font-size: clamp(17px, 1.7vw, 21px);
  font-weight: 400;
  line-height: 1.78;
  letter-spacing: -0.035em;
  white-space: nowrap;
}

.tech-capabilities {
  display: grid;
  grid-template-columns: minmax(190px, 28fr) minmax(0, 72fr);
  width: min(100%, 1180px);
  min-height: 530px;
  margin: clamp(72px, 8.5vw, 116px) auto 0;
}

.tech-navigation {
  align-self: start;
  padding: 10px 8% 0 0;
}

.tech-nav-item {
  position: relative;
  display: block;
  width: 100%;
  margin: 0;
  padding: 16px 0 16px 19px;
  border: 0;
  background: transparent;
  color: var(--tech-quiet);
  font: inherit;
  font-size: clamp(15px, 1.35vw, 18px);
  font-weight: 400;
  line-height: 1.35;
  letter-spacing: -0.04em;
  text-align: left;
  cursor: pointer;
}

.tech-nav-item::before {
  content: "";
  position: absolute;
  top: 9px;
  bottom: 9px;
  left: 0;
  width: 1px;
  background: transparent;
}

.tech-nav-item:hover,
.tech-nav-item:focus-visible { color: var(--tech-ink); }

.tech-nav-item:focus-visible { outline: 1px solid var(--tech-blue); outline-offset: 5px; }

.tech-nav-item.is-active {
  color: var(--tech-ink);
  font-size: clamp(16px, 1.47vw, 20px);
  font-weight: 500;
}

.tech-nav-item.is-active::before { background: var(--tech-blue); }

.tech-panels { padding-left: clamp(40px, 7vw, 110px); }

.tech-panel { width: min(100%, 760px); }

.tech-panel h2 {
  color: var(--tech-ink);
  font-size: clamp(33px, 4vw, 54px);
  font-weight: 500;
  line-height: 1.12;
  letter-spacing: -0.07em;
}

.tech-body {
  margin-top: clamp(34px, 4vw, 48px);
  color: var(--tech-copy);
  font-size: clamp(16px, 1.52vw, 19px);
  font-weight: 400;
  line-height: 1.9;
  letter-spacing: -0.025em;
}

.tech-body p + p { margin-top: 23px; }

.tech-why {
  margin-top: clamp(54px, 6vw, 76px);
  padding-top: 25px;
  border-top: 1px solid var(--tech-rule);
}

.tech-why h3 {
  color: var(--tech-ink);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.02em;
}

.tech-why p {
  margin-top: 15px;
  color: var(--tech-copy);
  font-size: clamp(16px, 1.38vw, 18px);
  line-height: 1.75;
  letter-spacing: -0.025em;
}

@media (max-width: 760px) {
  .tech-page { padding-right: 20px; padding-left: 20px; }
  .tech-kicker { font-size: 11px; }
  .tech-intro-copy { width: min(100%, 620px); margin-top: 29px; font-size: 16px; white-space: normal; }
  .tech-capabilities { display: block; min-height: 0; margin-top: 66px; }
  .tech-navigation { display: grid; grid-template-columns: 1fr 1fr; gap: 3px 17px; padding: 0; }
  .tech-nav-item { padding: 12px 0 12px 13px; font-size: 14px; }
  .tech-nav-item::before { top: 8px; bottom: 8px; }
  .tech-nav-item.is-active { font-size: 15px; }
  .tech-panels { margin-top: 62px; padding-left: 0; }
  .tech-panel h2 { font-size: clamp(31px, 9.4vw, 43px); }
  .tech-body { margin-top: 30px; font-size: 16px; line-height: 1.86; }
  .tech-body p + p { margin-top: 21px; }
  .tech-why { margin-top: 48px; }
}

@media (max-width: 420px) {
  .tech-navigation { grid-template-columns: 1fr; gap: 0; }
}