/* ============================================================
   danskliu.com — shared design system base
   Used by: /index.html, /resources/index.html (and future pages).
   Blog posts & thank-you are intentionally self-contained.
   Load this BEFORE each page's own <style> so page rules win.
   Page-specific tokens (--max-width, --spacing-lg/xl) may be
   overridden in the page's :root after this file loads.
   ============================================================ */

:root {
  --bg-primary: #f4f4f0;
  --bg-secondary: #ecece6;
  --bg-card: #ffffff;
  --text-primary: #0a0a0a;
  --text-secondary: #4a4a4a;
  --accent: #0056b3;
  --accent-light: #e6f0ff;
  --accent-subtle: #f0f7ff;
  --border: #d1d9e6;
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-sm: 0 1px 2px rgba(0, 86, 179, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 86, 179, 0.12);
  --shadow-lg: 0 8px 24px rgba(0, 86, 179, 0.16);
  --radius: 8px;
}

/* ── Dark mode tokens ── */
@media (prefers-color-scheme: dark) {
  :root {
    --bg-primary: #0f1117;
    --bg-secondary: #161822;
    --bg-card: #1a1d2b;
    --text-primary: #e8e8ed;
    --text-secondary: #a0a5b8;
    --accent: #4da8ff;
    --accent-light: #1a2540;
    --accent-subtle: #131a2b;
    --border: #2a2d3a;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.5);
  }
}

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

html {
  scroll-behavior: smooth;
  touch-action: manipulation;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: Optima, 'Alegreya Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  touch-action: pan-x pan-y;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Skip link for accessibility */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--accent);
  color: var(--bg-primary);
  padding: 8px 16px;
  z-index: 10000;
  transition: top 0.3s;
}
.skip-link:focus { top: 0; }

/* Primary button */
.cta-button {
  display: inline-block;
  padding: 0.875rem 2rem;
  background: var(--accent);
  color: var(--bg-primary);
  border: 1px solid var(--accent);
  font-weight: 600;
  transition: var(--transition);
  font-size: 0.85rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  text-decoration: none;
  margin-top: var(--spacing-sm);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}
.cta-button:hover {
  background: transparent;
  color: var(--accent);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}
.cta-button:active {
  transform: translateY(0);
}
@media (prefers-color-scheme: dark) {
  .cta-button { color: #fff; }
  .cta-button:hover { color: var(--accent); }
}

/* Scroll-triggered reveal animation */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1), transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}