:root {
  --ink: #141b19;
  --paper: #f6f7f5;
  --oxide: #17594a;
  --oxide-deep: #0e3d33;
  --haze: #6e7873;
  --hairline: #dee3df;
  --tile: #edf1ee;
  --font-display: "Newsreader", "Noto Sans TC", serif;
  --font-body: "Instrument Sans", "Noto Sans TC", -apple-system, sans-serif;
  --font-mono: "IBM Plex Mono", monospace;
}

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

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

body {
  font-family: var(--font-body);
  background: var(--paper);
  color: var(--ink);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

.wrap { max-width: 1040px; margin: 0 auto; padding: 0 24px; }

a { color: var(--oxide); text-decoration: none; }
a:hover { color: var(--oxide-deep); }
a:focus-visible, .btn:focus-visible {
  outline: 2px solid var(--oxide);
  outline-offset: 3px;
  border-radius: 2px;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--haze);
  margin-bottom: 20px;
}

/* Header */
.site-header {
  border-bottom: 1px solid var(--hairline);
  position: sticky;
  top: 0;
  background: rgba(246, 247, 245, 0.94);
  backdrop-filter: blur(6px);
  z-index: 10;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 18px;
  padding-bottom: 18px;
}
.brand { display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; }
.wordmark {
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 15px;
  letter-spacing: 0.18em;
}
.brand-zh { font-size: 12.5px; color: var(--haze); }
.nav { display: flex; gap: 26px; font-size: 14px; }
.nav a { color: var(--haze); }
.nav a:hover { color: var(--ink); }
.nav-contact { color: var(--oxide) !important; font-weight: 500; }

/* Hero */
.hero { padding: 96px 0 88px; }
.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
  gap: 64px;
  align-items: start;
}
.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(34px, 4.6vw, 50px);
  font-weight: 500;
  line-height: 1.16;
  letter-spacing: -0.01em;
  margin-bottom: 26px;
  max-width: 15em;
}
.standfirst {
  font-size: 17px;
  color: var(--haze);
  max-width: 34em;
  margin-bottom: 36px;
}
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.btn {
  display: inline-block;
  font-size: 14px;
  font-weight: 500;
  padding: 11px 24px;
  border: 1px solid var(--hairline);
  border-radius: 3px;
  color: var(--ink);
  transition: border-color 0.15s ease, background 0.15s ease;
}
.btn:hover { border-color: var(--haze); color: var(--ink); }
.btn-primary {
  background: var(--oxide);
  border-color: var(--oxide);
  color: #fff;
}
.btn-primary:hover { background: var(--oxide-deep); border-color: var(--oxide-deep); color: #fff; }

/* Element tile — signature */
.hero-tile { justify-self: end; text-align: left; max-width: 230px; }
.element-tile {
  width: 190px;
  aspect-ratio: 1;
  border: 1.5px solid var(--ink);
  border-radius: 4px;
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
  background: var(--tile);
}
.el-num { font-family: var(--font-mono); font-size: 15px; }
.el-symbol {
  font-family: var(--font-display);
  font-size: 64px;
  font-weight: 500;
  line-height: 1.05;
  margin-top: auto;
  color: var(--oxide);
}
.el-name { font-size: 14px; font-weight: 500; margin-top: 2px; }
.el-mass { font-family: var(--font-mono); font-size: 12px; color: var(--haze); margin-top: 2px; }
.tile-caption {
  font-size: 12.5px;
  color: var(--haze);
  line-height: 1.55;
  margin-top: 14px;
  max-width: 190px;
}

/* Sections */
.section { padding: 72px 0; }
.section-rule { border-top: 1px solid var(--hairline); }

/* Position diagram */
.position-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 48px minmax(0, 1fr) 48px minmax(0, 1fr);
  gap: 0;
  align-items: center;
  margin: 8px 0 28px;
}
.pos-col { display: flex; flex-direction: column; gap: 14px; }
.pos-node {
  border: 1px solid var(--hairline);
  border-radius: 4px;
  padding: 18px 20px;
  background: #fff;
}
.pos-node-center {
  border: 1.5px solid var(--oxide);
  background: var(--tile);
}
.pos-key {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.04em;
  margin-bottom: 4px;
}
.pos-node-center .pos-key { color: var(--oxide-deep); }
.pos-desc { display: block; font-size: 13px; color: var(--haze); line-height: 1.5; }
.pos-link { height: 1px; background: var(--haze); opacity: 0.55; }
.position-note { font-size: 15px; color: var(--haze); max-width: 40em; }

/* Cards */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}
.card {
  background: #fff;
  border: 1px solid var(--hairline);
  border-radius: 4px;
  padding: 26px 24px 28px;
}
.card-key {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--oxide);
  margin-bottom: 16px;
}
.card h3 {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 500;
  line-height: 1.3;
  margin-bottom: 10px;
}
.card p:last-child { font-size: 14px; color: var(--haze); line-height: 1.65; }

/* Approach */
.approach-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
  gap: 64px;
}
.credo {
  font-family: var(--font-display);
  font-size: clamp(24px, 3vw, 31px);
  font-weight: 500;
  line-height: 1.3;
  margin-bottom: 20px;
  max-width: 18em;
}
.approach-body { font-size: 15px; color: var(--haze); max-width: 36em; }

.assay { border-top: 1px solid var(--ink); }
.assay > div {
  display: grid;
  grid-template-columns: 130px minmax(0, 1fr);
  gap: 12px;
  padding: 11px 0;
  border-bottom: 1px solid var(--hairline);
  font-size: 13.5px;
}
.assay dt { font-family: var(--font-mono); font-size: 12px; color: var(--haze); padding-top: 1px; }
.assay dd { font-weight: 500; }

/* Footer */
.site-footer {
  border-top: 1px solid var(--ink);
  background: var(--tile);
  padding: 56px 0 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
  gap: 48px;
  padding-bottom: 40px;
}
.footer-name { font-family: var(--font-mono); font-weight: 500; font-size: 14px; letter-spacing: 0.08em; }
.footer-zh { font-size: 13.5px; margin-top: 2px; }
.footer-addr { font-size: 13px; color: var(--haze); margin-top: 10px; max-width: 32em; }
.footer-contact .eyebrow { margin-bottom: 10px; }
.footer-mail { font-size: 15px; font-weight: 500; }
.footer-legal {
  border-top: 1px solid var(--hairline);
  padding-top: 16px;
  padding-bottom: 20px;
}
.footer-legal p { font-size: 12px; color: var(--haze); }

/* Responsive */
@media (max-width: 860px) {
  .hero { padding: 64px 0 56px; }
  .hero-grid { grid-template-columns: 1fr; gap: 44px; }
  .hero-tile { justify-self: start; }
  .position-grid { grid-template-columns: 1fr; gap: 14px; }
  .pos-link { width: 1px; height: 22px; margin: 0 auto; }
  .approach-grid { grid-template-columns: 1fr; gap: 44px; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .nav { gap: 18px; }
}
@media (max-width: 560px) {
  .header-inner { flex-direction: column; align-items: flex-start; gap: 10px; }
  .nav { flex-wrap: wrap; }
}