/* solexus.ai — stylesheet */

:root {
  --paper: #f7f6f2;
  --ink: #17181a;
  --ink-2: #4a4c50;
  --ink-3: #8a8c90;
  --rule: #d9d7d0;
  --accent: #1f3a5f;
  --accent-soft: #e7ebef;
  --paper-deep: #efeee9;

  --sans: "Inter", system-ui, -apple-system, sans-serif;
  --serif: "Newsreader", Georgia, "Times New Roman", serif;
  --measure: 62ch;
}

html[lang="zh-TW"] {
  --sans: "Noto Sans TC", "Inter", system-ui, sans-serif;
  --serif: "Noto Serif TC", "Newsreader", serif;
}
html[lang="zh-CN"] {
  --sans: "Noto Sans SC", "Inter", system-ui, sans-serif;
  --serif: "Noto Serif SC", "Newsreader", serif;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
p { margin: 0; }
h1, h2, h3 { margin: 0; font-weight: 500; }
ul, dl, dd { margin: 0; padding: 0; }
ul { list-style: none; }

.skip-link {
  position: fixed; top: 8px; left: 16px; z-index: 30;
  padding: 8px 12px; background: var(--ink); color: var(--paper);
  transform: translateY(-160%); transition: transform .18s ease;
}
.skip-link:focus { transform: translateY(0); }

.wrap { max-width: 1120px; margin: 0 auto; padding: 0 32px; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 10;
  background: rgba(247, 246, 242, 0.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--rule);
}
.header-row {
  display: flex; align-items: center; justify-content: space-between;
  min-height: 68px; gap: 24px;
}
.logo { display: flex; align-items: center; gap: 10px; color: var(--ink); }
.logo-mark { width: 26px; height: 26px; flex: none; }
.logo-text { font-weight: 600; letter-spacing: -0.02em; font-size: 1.08rem; line-height: 1; }
.logo-text span { font-weight: 400; color: var(--ink-3); }
.footer-brand { display: inline-flex; align-items: center; gap: 8px; }
.footer-brand .logo-mark { width: 18px; height: 18px; }
.site-nav { display: flex; gap: 28px; font-size: 0.92rem; color: var(--ink-2); }
.site-nav a { position: relative; padding: 8px 0; }
.site-nav a::after {
  content: ""; position: absolute; left: 0; right: 100%; bottom: 2px;
  border-bottom: 1px solid var(--accent); transition: right .2s ease;
}
.site-nav a:hover, .site-nav a[aria-current="true"] { color: var(--ink); }
.site-nav a:hover::after, .site-nav a[aria-current="true"]::after { right: 0; }
.lang { display: flex; gap: 2px; font-size: 0.82rem; }
.lang button {
  font: inherit; background: none; border: 0; cursor: pointer;
  color: var(--ink-3); padding: 7px 9px; border-radius: 2px;
}
.lang button:hover { color: var(--ink); }
.lang button.active { color: var(--ink); background: var(--accent-soft); }
.lang button:focus-visible, .site-nav a:focus-visible, .toc a:focus-visible, .email:focus-visible { outline: 2px solid var(--accent); outline-offset: 4px; }

/* Intro */
.intro { padding: 92px 0 104px; border-bottom: 1px solid var(--rule); }
.intro-topline {
  display: flex; align-items: center; justify-content: space-between; gap: 24px;
  margin-bottom: 30px; color: var(--ink-3); font-size: .74rem;
  letter-spacing: .12em; text-transform: uppercase;
}
.kicker { color: var(--accent); font-weight: 600; }
.kicker::before { content: ""; display: inline-block; width: 24px; margin: 0 10px 3px 0; border-top: 1px solid currentColor; }
.intro-edition { font-variant-numeric: tabular-nums; }
.intro h1 {
  font-family: var(--serif);
  font-size: clamp(2.15rem, 4.4vw, 3.8rem);
  line-height: 1.12;
  letter-spacing: -0.02em;
  max-width: 22em;
  text-wrap: pretty;
}
.intro-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 64px;
  margin-top: 64px; align-items: start;
}
.intro-grid > p { max-width: var(--measure); color: var(--ink-2); font-size: 1.04rem; }
.toc li { border-top: 1px solid var(--rule); }
.toc li:last-child { border-bottom: 1px solid var(--rule); }
.toc a { display: grid; grid-template-columns: 34px 1fr 18px; gap: 14px; padding: 19px 0; align-items: baseline; transition: padding .2s ease; }
.toc a::after { content: "↗"; color: var(--accent); opacity: 0; transform: translate(-6px, 5px); transition: opacity .2s ease, transform .2s ease; }
.toc a:hover { padding-left: 8px; }
.toc a:hover::after { opacity: 1; transform: translate(0, 0); }
.toc a:hover em { color: var(--accent); }
.toc span { font-size: 0.8rem; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.toc em { font-style: normal; font-weight: 500; }

/* Blocks */
.block { padding: 104px 0; border-bottom: 1px solid var(--rule); }
.block:nth-of-type(odd) { background: rgba(255, 255, 255, .34); }
.block-grid {
  display: grid; grid-template-columns: 300px 1fr; gap: 64px; align-items: start;
}
.block-label { position: sticky; top: 92px; }
.num { display: block; font-size: 0.8rem; color: var(--ink-3); margin-bottom: 14px; font-variant-numeric: tabular-nums; }
.block-label h2 {
  font-family: var(--serif);
  font-size: 1.65rem; line-height: 1.25; letter-spacing: -0.01em;
}
.block-body { max-width: var(--measure); }
.block-body > p { margin-bottom: 1.2em; }
.block-body > p:last-child { margin-bottom: 0; }

/* Flow diagram */
.flow {
  display: grid; grid-template-columns: 1fr 40px 1fr 40px 1fr; align-items: stretch;
  margin: 48px 0 12px; padding: 0;
}
.flow-node {
  display: flex; flex-direction: column; gap: 6px;
  padding: 19px; border: 1px solid var(--rule); background: rgba(255,255,255,.55);
  font-size: 0.9rem; line-height: 1.45;
}
.flow-node small { font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--ink-3); }
.flow-core { border-color: var(--ink); }
.flow-core small { color: var(--ink); font-weight: 600; text-transform: none; letter-spacing: 0; font-size: 0.85rem; }
.flow-arrow { position: relative; }
.flow-arrow::before {
  content: ""; position: absolute; top: 50%; left: 6px; right: 6px;
  border-top: 1px solid var(--ink-3);
}
.flow-arrow::after {
  content: ""; position: absolute; top: 50%; right: 6px;
  width: 6px; height: 6px; border-top: 1px solid var(--ink-3); border-right: 1px solid var(--ink-3);
  transform: translateY(-50%) rotate(45deg);
}
.flow-caption { grid-column: 1 / -1; margin-top: 13px; color: var(--ink-3); font-size: .78rem; font-style: italic; }

/* Facts */
.facts { border-top: 1px solid var(--rule); margin-top: 8px; }
.facts > div {
  display: grid; grid-template-columns: 140px 1fr; gap: 24px;
  padding: 14px 0; border-bottom: 1px solid var(--rule); font-size: 0.95rem;
}
.facts dt { color: var(--ink-3); }

/* Sub sections */
.sub { margin-top: 40px; padding-top: 32px; border-top: 1px solid var(--rule); }
.sub h3 { font-size: 1.1rem; margin-bottom: 10px; }
.sub p { color: var(--ink-2); }
.plain-list { margin-top: 12px; padding-left: 1.2em; list-style: disc; color: var(--ink); }
.plain-list li { margin: 4px 0; }
.plain-list li::marker { color: var(--ink-3); }

/* Contact */
.contact .block-label h2 { font-size: 1.4rem; }
.email {
  display: inline-block; margin-top: 18px;
  font-family: var(--serif); font-size: 1.6rem;
  border-bottom: 1px solid var(--ink);
}
.email:hover { color: var(--accent); border-color: var(--accent); }

/* Footer */
.site-footer { padding: 32px 0 48px; font-size: 0.82rem; color: var(--ink-3); }
.footer-row { display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; }

/* Responsive */
@media (max-width: 900px) {
  .block-grid { grid-template-columns: 1fr; gap: 28px; }
  .block-label { position: static; }
  .intro-grid { grid-template-columns: 1fr; gap: 40px; }
}
@media (max-width: 640px) {
  body { font-size: 16px; }
  .wrap { padding: 0 20px; }
  .site-nav { display: none; }
  .intro { padding: 68px 0 72px; }
  .intro-topline { align-items: flex-start; flex-direction: column; gap: 10px; margin-bottom: 23px; }
  .intro-edition { padding-left: 34px; }
  .intro h1 { font-size: clamp(2.05rem, 10vw, 3.1rem); line-height: 1.1; }
  .intro-grid { margin-top: 42px; gap: 34px; }
  .block { padding: 64px 0; }
  .flow { grid-template-columns: 1fr; margin: 36px 0; }
  .flow-arrow { height: 32px; }
  .flow-arrow::before { left: 50%; right: auto; top: 4px; bottom: 4px; border-top: 0; border-left: 1px solid var(--ink-3); }
  .flow-arrow::after { left: 50%; right: auto; top: auto; bottom: 5px; transform: translateX(-50%) rotate(135deg); }
  .facts > div { grid-template-columns: 1fr; gap: 4px; }
  .footer-row { flex-direction: column; gap: 8px; }
}