/* ================================================================
   数迹团队 DataTrace
   Prose-only. Minimal. Editorial.
   ================================================================ */

/* ---------------------------------------------------------------
   1. Tokens
   --------------------------------------------------------------- */

:root,
:root[data-theme="dark"] {
  --bg: #0e0e10;
  --bg-subtle: #141416;
  --bg-elevated: #1a1a1d;
  --border: #25252a;
  --border-strong: #34343a;
  --fg: #d8d8dc;
  --fg-muted: #9b9ba3;
  --fg-subtle: #6c6c75;
  --accent: #60a5fa;
  --accent-subtle: rgba(96, 165, 250, 0.10);
  --dot-color: rgba(255, 255, 255, 0.10);
  --dot-line: rgba(255, 255, 255, 0.04);
  --dot-glow: rgba(255, 255, 255, 0.25);
}

:root[data-theme="light"] {
  --bg: #ffffff;
  --bg-subtle: #f5f5f7;
  --bg-elevated: #eeeef0;
  --border: #d4d4d8;
  --border-strong: #a1a1aa;
  --fg: #09090b;
  --fg-muted: #3f3f46;
  --fg-subtle: #71717a;
  --accent: #2563eb;
  --accent-subtle: rgba(37, 99, 235, 0.08);
  --dot-color: rgba(0, 0, 0, 0.06);
  --dot-line: rgba(0, 0, 0, 0.025);
  --dot-glow: rgba(0, 0, 0, 0.12);
}

/* ---------------------------------------------------------------
   2. Reset
   --------------------------------------------------------------- */

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: "Inter", -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 15px; font-weight: 400;
  line-height: 1.72;
  color: var(--fg-muted);
  background: var(--bg);
  transition: background 0.3s ease, color 0.3s ease;
}

a { color: inherit; text-decoration: none; }
button { cursor: pointer; border: none; background: none; font: inherit; color: inherit; }

/* ---------------------------------------------------------------
   3. Particle
   --------------------------------------------------------------- */

#particle-canvas {
  position: fixed; top: 0; left: 0;
  width: 100%; height: 100%;
  z-index: 0; pointer-events: none;
}

/* ---------------------------------------------------------------
   4. Mono
   --------------------------------------------------------------- */

.mono {
  font-family: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 10.5px; letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--fg-subtle);
}

/* ---------------------------------------------------------------
   5. Header
   --------------------------------------------------------------- */

.site-header {
  position: sticky; top: 0; z-index: 40;
  height: 64px;
  border-bottom: 1px solid var(--border);
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.header-inner {
  max-width: 960px; margin: 0 auto;
  height: 100%;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 32px;
}

.brand {
  display: flex; align-items: center; gap: 8px;
  color: var(--fg); font-weight: 600; font-size: 16px;
  letter-spacing: -0.01em;
}

.brand-mark { font-size: 17px; color: var(--accent); }

.header-nav { display: flex; gap: 24px; font-size: 14px; color: var(--fg-muted); }
.header-nav a { transition: color 0.15s; }
.header-nav a:hover { color: var(--fg); }

.theme-toggle {
  display: flex; align-items: center; justify-content: center;
  width: 34px; height: 34px; border-radius: 6px;
  color: var(--fg-subtle);
  transition: background 0.15s, color 0.15s;
}

.theme-toggle:hover { background: var(--bg-subtle); color: var(--fg); }

[data-theme="dark"]  .ico-sun  { display: block; }
[data-theme="dark"]  .ico-moon { display: none;  }
[data-theme="light"] .ico-sun  { display: none;  }
[data-theme="light"] .ico-moon { display: block; }

/* ---------------------------------------------------------------
   6. Layout
   --------------------------------------------------------------- */

.main-layout {
  position: relative; z-index: 1;
}

/* ---------------------------------------------------------------
   7. Hero
   --------------------------------------------------------------- */

.hero {
  padding: 100px 32px 88px;
  max-width: 660px; margin: 0 auto;
}

.hero-eyebrow {
  font-family: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 10.5px; letter-spacing: 0.28em; text-transform: uppercase;
  color: var(--fg-subtle);
  margin-bottom: 24px;
}

.hero-title {
  font-size: clamp(32px, 6vw, 52px);
  font-weight: 600; line-height: 1.15;
  letter-spacing: -0.015em;
  color: var(--fg);
  margin-bottom: 28px;
}

.hero-accent { color: var(--accent); }

.hero-desc {
  font-size: 16px; line-height: 1.78;
  color: var(--fg-muted);
}

/* ---------------------------------------------------------------
   8. Prose
   --------------------------------------------------------------- */

.prose {
  max-width: 660px; margin: 0 auto;
  padding: 0 32px 64px;
}

.prose h2 {
  font-size: 1.3rem; font-weight: 600;
  color: var(--fg);
  letter-spacing: -0.01em;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
  margin: 2.2rem 0 1rem;
  scroll-margin-top: 100px;
}

.prose h2:first-of-type {
  border-top: none; padding-top: 0; margin-top: 0;
}

.prose p {
  font-size: 15px; line-height: 1.78;
  color: var(--fg-muted);
  margin: 0.9rem 0;
}

.prose p a {
  color: var(--accent);
  transition: opacity 0.15s;
}

.prose p a:hover { opacity: 0.75; }

.prose-lead {
  font-size: 16px !important;
  color: var(--fg-muted) !important;
}

.prose-note {
  font-size: 13.5px !important;
  color: var(--fg-subtle) !important;
  line-height: 1.65;
  padding-left: 14px;
  border-left: 2px solid var(--border);
}

.prose-last { padding-bottom: 88px; }

/* ---------------------------------------------------------------
   9. Inline link (email)
   --------------------------------------------------------------- */

.inline-link {
  font-family: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 15px;
  color: var(--accent) !important;
  border-bottom: 1px solid var(--accent-subtle);
  transition: border-color 0.15s;
}

.inline-link:hover {
  border-bottom-color: var(--accent);
  opacity: 1 !important;
}

/* ---------------------------------------------------------------
   10. Team lines
   --------------------------------------------------------------- */

.team-line {
  padding: 20px 0;
  border-bottom: 1px solid var(--border);
}

.team-line:first-of-type {
  border-top: 1px solid var(--border);
  margin-top: 0.6rem;
}

.team-name {
  font-size: 1rem; font-weight: 600;
  color: var(--fg);
  transition: color 0.15s;
}

.team-name:hover { color: var(--accent); }

.team-sep {
  margin: 0 8px;
  color: var(--fg-subtle);
  font-size: 13px;
}

.team-role { font-size: 10px; }

.team-desc {
  font-size: 13.5px !important;
  color: var(--fg-muted) !important;
  line-height: 1.6;
  margin-top: 6px !important;
}

/* ---------------------------------------------------------------
   11. Footer
   --------------------------------------------------------------- */

.footer {
  border-top: 1px solid var(--border);
  padding: 36px 32px;
}

.footer-inner {
  max-width: 660px; margin: 0 auto;
  display: flex; align-items: center; gap: 10px;
  flex-wrap: wrap;
  font-size: 13px; color: var(--fg-muted);
}

.footer-logo { font-weight: 600; color: var(--fg); }
.footer-ver { font-size: 10px; }
.footer-dot { color: var(--fg-subtle); font-size: 11px; }

.footer-inner a {
  color: var(--fg-subtle);
  transition: color 0.15s;
}

.footer-inner a:hover { color: var(--fg); }

/* ---------------------------------------------------------------
   12. Focus
   --------------------------------------------------------------- */

a:focus-visible, button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 3px;
}

/* ---------------------------------------------------------------
   13. Reduced motion
   --------------------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
}

/* ---------------------------------------------------------------
   14. Responsive
   --------------------------------------------------------------- */

@media (max-width: 768px) {
  .header-inner { padding: 0 18px; }
  .header-nav { display: none; }

  .hero { padding: 64px 20px 56px; }
  .hero-title { font-size: clamp(26px, 8vw, 40px); }

  .prose { padding: 0 20px 48px; }
  .prose-last { padding-bottom: 64px; }

  .footer { padding: 28px 20px; }
  .footer-inner { gap: 6px; font-size: 12px; }
}